cssi/SciSciGPT-SciSciNet huggingface dataset:
Two Magnetar Candidates in HESS Supernova Remnants

We identify two candidate magnetars in archival X-ray observations of HESS-detected shell-type supernova remnants (SNRs). X-ray point sources in CTB 37B coincident with HESS J1713 - 381 and in G353.6 - 0.7 coincident with HESS J1731 - 347 both have anomalous X-ray pulsar (AXP) like spectra, much softer than those of ordinary, rotation-powered pulsars, and no optical/IR counterparts. The spectrum of CXOU J171405.7 - 381031 in CTB 37B has a hard excess above 6 keV, which may be similar to such components seen in some AXPs. A new Chandra observation of this object reveals a highly significant pulsed signal at P = 3.82 s with pulsed fraction f{sub p} = 0.31. Analysis of an XMM-Newton observation of the second candidate, XMMU J173203.3 - 344518 in G353.6 - 0.7, yields only marginal evidence for a 1 s period. If it is not a magnetar, then it could be a weakly magnetized central compact object. Considering that these HESS sources previously attributed to the SNR shells are possibly centrally peaked, we hypothesize that their pulsars may contribute to diffuse TeV emission. These identifications potentially double the number of magnetar/SNR associations in the Galaxy and can be used to investigate the energetics andmore » asymmetries of the supernovae that give rise to magnetars.« less
On page migration and other relaxed task systems

This paper is concerned with the page migration (or file migration) problem (Black and Sleator, Technical Report CMU-CS-89-201, Department of Computer Science, Carnegie-Mellon University, 1989) as part of a large class of on-line problems. The page migration problem deals with the management of pages residing in a network of processors. In the classical problem there is only one copy of each page which is accessed by different processors over time. The page is allowed to be migrated between processors. However a migration incurs higher communication cost than an access (proportionally to the page size). The problem is that of deciding when and where to migrate the page in order to lower access costs. A more general setting is the k-page migration problem where we wish to maintain k copies of the page. The page migration problems are concerned with a dilemma common to many on-line problems: determining when it is beneficial to make configuration changes. We deal with the relaxed task systems model which captures a large class of problems of this type, that can be described as the generalization of some original task system problem (Borodin et al., J. ACM 39(4) (1992) 745-763). Given a c-competitive algorithm for a task system we show how to obtain a deterministic O(c2) and randomized O(c) competitive algorithms for the corresponding relaxed task system. The result implies deterministic algorithms for k-page migration by using k-server (Manasse et al., J. Algorithms 11(2) (1990) 208-230) algorithms, and for network leasing by using generalized Steiner tree algorithms (Awerbuch et al., Proc 7th Ann. ACM-SIAM Symp. on Discrete Algorithms, January 1996, pp. 68-74), as well as providing solutions for natural generalizations of other problems (e.g. storage rearrangement (Fiat et al., Proc. 36th Ann. IEEE Symp. on Foundations of Computer Science, October 1995, pp. 392-403)). We further study some special cases of the k-page migration problem and get optimal deterministic algorithms. For the classical page migration problem we present a deterministic algorithm that achieves a competitive ratio of ~ 4:086, improving upon the previously best competitive ratio of 7 (Awerbuch et al., Proc. 25th ACM Symp. on Theory of Computing, May 1993, pp. 164-173). (The current lower bound on the problem is ~ 3:148 (Chrobak et al., J. Algorithms 24(1) (1997) 124-157). Copyright 2001 Elsevier Science B.V.
The PMPO syndrome (postmenopausal palpable ovary syndrome).

If we are to save more women and diminish the mortality rate from ovarian cancer, we must become more liberal in our indications for operation. We suggest that the palpation of what appears to be a normal-sized ovary for a patient three to five years postmenopausal is indicative of an ovarian tumor and should be investigated promptly. These patients should not be followed and re-evaluated but rather subjected to proof as to the presence or absence of an ovarian tumor. To wait until one feels a solid tumor mass of up to 5 cm. and expect a cure is an exercise in fancy and futility. John Gardner said, “We are all faced with wonderful opportunities brilliantly disguised as insoluble problems.” Ovarian cancer is not insoluble. Perhaps, by adding a small segment at a time, the total picture will emerge to the benefit of our patients. Remember the PMPO Syndrome!
Probing the MSSM Higgs sector via weak boson fusion at the LHC

Abstract In the MSSM weak boson fusion produces the two CP even Higgs bosons with a combined strength equivalent to the production of the Standard Model Higgs boson. The ττ decay mode – supplemented by γγ – provides a highly significant signal for at least one of the CP even Higgs bosons at the LHC with reasonable luminosity. The accessible parameter space covers the entire physical range which will be left unexplored by LEP2.
Land use effects on soil carbon fractions in the southeastern United States. II. Changes in soil carbon fractions along a forest to pasture chronosequence

Since land use change can have significant impacts on regional biogeochemistry, we investigated how conversion of forest and cultivation to pasture impact soil C and N cycling. In addition to examining total soil C, we isolated soil physiochemical C fractions in order to understand the mechanisms by which soil C is sequestered or lost. Total soil C did not change significantly over time following conversion from forest, though coarse (250–2,000 μm) particulate organic matter C increased by a factor of 6 immediately after conversion. Aggregate mean weight diameter was reduced by about 50% after conversion, but values were like those under forest after 8 years under pasture. Samples collected from a long-term pasture that was converted from annual cultivation more than 50 years ago revealed that some soil physical properties negatively impacted by cultivation were very slow to recover. Finally, our results indicate that soil macroaggregates turn over more rapidly under pasture than under forest and are less efficient at stabilizing soil C, whereas microaggregates from pasture soils stabilize a larger concentration of C than forest microaggregates. Since conversion from forest to pasture has a minimal impact on total soil C content in the Piedmont region of Virginia, United States, a simple C stock accounting system could use the same base soil C stock value for either type of land use. However, since the effects of forest to pasture conversion are a function of grassland management following conversion, assessments of C sequestration rates require activity data on the extent of various grassland management practices.
THE NEW TRANSITING PLANET OGLE-TR-56b: ORBIT AND ATMOSPHERE

Motivated by the identification of the very close-in extrasolar giant planet OGLE-TR-56b (P = 1.2 days, a = 0.023 AU, Mp = 0.9MJ), we explore implications of its existence for problems of tidal dissipation, planet migration, and atmospheric stability. The small orbit of OGLE-TR-56b makes the planet an interesting test particle case for tidal dissipation in stellar convection zones. We show that it favors prescriptions of suppressed convective eddy viscosity. Precise timing of the transits of OGLE-TR-56b might place interesting constraints on stellar convection theory if orbital period change is detected in the near future. Another interesting issue related to the new planet is the origin of its close orbit; OGLE-TR-56b may be a survivor of Roche lobe overflow mass loss. Living in such close proximity to its parent star, OGLE-TR-56b should have temperatures in the dayside hemisphere reaching 1900 K, and we find that only few condensates could form clouds, if at all, under those conditions—mostly Al2O3 and Fe(s). We explore the issue of atmosphere evaporation and find that the planet's atmosphere is stable over its lifetime. The large size of the planet (Rp = 1.3 ± 0.15 RJ) might also require additional energy, similar to HD 209458b.
Response to Endicott: The Case of the Wise Electrician

Timothy Endicott tells the tale of the "wise electrician." Speaking as a homeowner, I should be pleased to hear about the moderately competent, reasonably affordable electrician. But that is not what Timothy has put on offer. Let us talk then about his much more interesting guy. The main activities of the Wise Electrician are two. One is that he installs legally required Grade 5 insulation in everyone's home save one. The second is that on his own ceiling light circuits he uses Grade 4 insulation. Number 4 is cheaper to acquire and, in his professional judgment, it is safe. We are not invited to infer that the Wise Electrician's abode is unique; number 4 would apparently be safe in many homes, and just as cheap for their owners. In fact, the Wise Electrician would install Grade 4 in those houses, too, but for one fact: it would be illegal. What makes our man so interesting is that it is illegal to install Grade 4 in his house too. The law says: Grade 5 for "all home wiring" and that's that. No exceptions listed.
The Dark Spot in the atmosphere of Uranus in 2006: Discovery, description, and dynamical simulations ✩

Abstract We report the first definitive detection of a discrete dark atmospheric feature on Uranus in 2006 using visible and near-infrared images from the Hubble Space Telescope and the Keck II 10-m telescope. Like Neptune's Great Dark Spots, this Uranus Dark Spot had bright companion features that exhibited considerable variability in brightness and location relative to the Dark Spot. We detected the feature or its bright companions on 16 June (Hubble), 30 July and 1 August (Keck), 23–24 August (Hubble), and 15 October (Keck). The dark feature—detected at latitude ∼ 28 ± 1 ° N with an average physical extent of roughly 2° (1300 km) in latitude and 5° (2700 km) in longitude—moved with a nearly constant zonal velocity of 43.1 ± 0.1 m s − 1 , which is roughly 20 m s−1 greater than the average observed speed of bright features at this latitude. The dark feature's contrast and extent varied as a function of wavelength, with largest negative contrast occurring at a surprisingly long wavelength when compared with Neptune's dark features: the Uranus feature was detected out to 1.6 μm with a contrast of −0.07, but it was undetectable at 0.467 μm; the Neptune GDS seen by Voyager exhibited its most prominent contrast of −0.12 at 0.48 μm, and was undetectable longward of 0.7 μm. Computational fluid dynamic simulations of the dark feature on Uranus suggest that structure in the zonal wind profile may be a critical factor in the emergence of large sustained vortices.
Dynamics of Constrained Multibody Systems

Etude des equations de mouvement de systemes a n corps soumis a des contraintes soit geometriques (boucles fermees), soit cinematiques (mouvement specifique)
Evaluation of the rotational barrier in the bis-(dimethylamido) phosphenium cation by spin saturation transfer and 1H and 13C complete bandshape analysis

Abstract The barrier to rotation about the phosphorus-nitrogen bond in the bis(dimethylamido) phosphenium cation has been determined by 13C and 1H DNMR complete bandshape analysis and spin saturation transfer methodologies. Arrhenius activation energies for this simple two-site exchange process as derived from the three techniques are 11.2, 11.0 and 12.7 kcal mol−1, respectively. Corresponding activation enthalpies are 10.7, 10.5 and 12.2 kcal mol−1. Activation energies and enthalpies derived from these methods are thus in agreement within 1.7 kcal of one another.
Representing Risk Preferences in Expected Utility Based Decision Models

Users of expected utility based decision models frequently find it useful or necessary to specify a functional form that represents the risk preferences of a decision maker. Having additional functional forms from which to choose would be helpful. The literature so far has provided several such functional forms for the utility function itself. The discussion presented here indicates that providing a functional form for the marginal utility function is an alternate and equally useful way to represent risk preferences. Furthermore, functional forms for marginal utility are easier to provide, and there exist functional forms for marginal utility that represent simple risk preferences for which there is no associated functional form for the utility function. Several functional forms for marginal utility are suggested, and the class of isoelastic risk preferences is identified and discussed.
Recovery of bivariate band-limited functions using scattered translates of the Poisson kernel

This paper continues the study of interpolation operators on scattered data. We introduce the Poisson interpolation operator and prove various properties of this operator. The main result concerns functions whose Fourier transforms are concentrated near the origin, specifically functions belonging to the Paley-Wiener space PW B β . We show that one may recover these functions from their samples on a complete interpolating sequence for - ? , ? 2 by using the Poisson interpolation operator, provided that 0 < β < ( 3 - 8 ) ? .
Extensible knowledge representation: the case of description reasoners

This paper offers an approach to extensible knowledge representation and reasoning for the Description Logic family of formalisms. The approach is based on the notion of adding new concept constructors, and includes a heuristic methodology for specifying the desired extensions, as well as a modularized software architecture that supports implementing extensions. The architecture detailed here falls in the normalize-compared paradigm, and supports both intentional reasoning (subsumption) involving concepts, and extensional reasoning involving individuals after incremental updates to the knowledge base. The resulting approach can be used to extend the reasoner with specialized notions that are motivated by specific problems or application areas, such as reasoning about dates, plans, etc. In addition, it provides an opportunity to implement constructors that are not currently yet sufficiently well understood theoretically, but are needed in practice. Also, for constructors that are provably hard to reason with (e.g., ones whose presence would lead to undecidability), it allows the implementation of incomplete reasoners where the incompleteness is tailored to be acceptable for the application at hand.
Rotating-wave-plate Stokes polarimeter for differential group delay measurements of polarization-mode dispersion.

We present a description and detailed uncertainty analysis of a polarization-mode dispersion (PMD) measurement system that uses the Jones matrix eigenanalysis measurement technique based on a rotating-wave-plate Stokes polarimeter. The uncertainty of the system is 3.2 fs (∼95% confidence interval) and is due primarily to PMD in the fiber leads of the measurement system.
Cumulant Correlators from the APM

This work presents a set of new statistics, the cumulant correlators (CCs), aimed at high-precision analysis of the galaxy distribution. They form a symmetric matrix, QNM, related to moment correlators in the same way cumulants are related to the moments of the distribution. They encode more information than the usual cumulants SN, and their extraction from data is similar to the calculation of the two-point correlation function. Perturbation theory (PT), its generalization in the extended perturbation theory (EPT), and the hierarchical assumption (HA) have simple predictions for these statistics. As an example, the factorial moment correlators measured by Szapudi and coworkers in the APM catalog are reanalyzed using this technique. While the previous analysis assumed hierarchical structure constants, this method can directly investigate the validity of the HA, along with PT and EPT. The results in agreement with previous findings indicate that, at the small scales used for this analysis, the APM data support the HA. When all nonlinear corrections are taken into account, it is a good approximation at the 20% level. It appears that PT, and a natural generalization of EPT for CCs, does not provide such a good fit for the APM at small scales. Once the validity of the HA is approximately established, CCs can separate the amplitudes of different tree types in the hierarchy up to fifth order. As an example, the weights for the fourth-order tree topologies are calculated including all nonlinear corrections.
ARM Wrestling: Valuing Adjustable Rate Mortgages Indexed to the Eleventh District Cost of Funds

This article analyzes adjustable rate mortgages (ARMs) based on the Eleventh District Cost of Funds Index (EDCOFI). The behavior of EDCOFI was examined over the period 1981–1993. Adjustments in this index lag substantially behind term structure fluctuations. Also, the seasonality and days-in-the-month effects noted by previous authors are really symptoms of a January effect. A finite difference valuation algorithm was developed which accounts for all usual ARM contractual features, in addition to the dynamics of EDCOFI. This pricing algorithm allows us to determine endogenously the optimal prepayment strategy for mortgage holders, and hence the value of their prepayment options. The dynamics of EDCOFI give significant value to this option, typically around 0.5% of the remaining principal on the loan.
Total Syntheses of Lyconadins: Finding Efficiency and Diversity

Lyconadins A–C are important members of the Lycopodium alkaloid family with challenging structural features and interesting biological profiles. Herein, various synthetic strategies and methods for their preparation are summarized with the focus on constructive bond formation and our efficient and divergent synthesis based on a functional group pairing (FGP) strategy.
Wifi-Reports: Improving Wireless Network Selection with Collaboration

Wi-Fi clients can obtain much better performance at some commercial hot spots than others. Unfortunately, there is currently no way for users to determine which hot spot access points (APs) will be sufficient to run their applications before purchasing access. To address this problem, this paper presents Wifi-Reports, a collaborative service that provides Wi-Fi clients with historical information about AP performance and application support. The key research challenge in Wifi-Reports is to obtain accurate user-submitted reports. This is challenging because two conflicting goals must be addressed in a practical system: preserving the privacy of users' reports and limiting fraudulent reports. We introduce a practical cryptographic protocol that achieves both goals, and address the important engineering challenges in building Wifi-Reports. Using a measurement study of APs in a busy commercial district, we show that Wifi-Reports would improve the performance over previous AP selection approaches in 30-60 percent of locations.
The Honeycomb Conjecture

This article gives a proof of the classical honeycomb conjecture: any partition of the plane into regions of equal area has perimeter at least that of the regular hexagonal honeycomb tiling.
Stable Matching With Incomplete Information

We formulate a notion of stable outcomes in matching problems with one-sided asymmetric information. The key conceptual problem is to formulate a notion of a blocking pair that takes account of the inferences that the uninformed agent might make from the hypothesis that the current allocation is stable. We show that the set of stable outcomes is nonempty in incomplete information environments, and is a superset of the set of complete-information stable outcomes. We then provide sucient conditions for incomplete-information stable matchings to be ecient. Lastly, we dene a notion of price sustainable allocations and show that the set of incomplete- information stable matchings is a subset of the set of such allocations.
Minimum Advertised-Price Policy Rules and Retailer Behavior: An Experiment by Hewlett-Packard

We tested the effects of various policy rules on retailer behavior in laboratory experiments conducted at Hewlett-Packard Laboratories. Our experimental design models the multifaceted contemporary market for consumer computer products and is quite complex, but we found that participants can make effective decisions and that their behavior is sensitive to variations in policies. Based on our results, Hewlett-Packard changed its policies; for example, it made the consequences for violations forward looking as well as backward looking. This line of research appears promising for complex industrial environments.
Nutrition, Posture, Gait, Face. and Skin

Careful observation should arouse the optometrist's index of suspicion not only of refractive disorders but of those disturbances requiring medical referral which might have otherwise been missed or overlooked.
Three-graviton scattering in Matrix theory revisited

Abstract We consider a subset of the terms in the effective potential describing three-graviton interactions in Matrix theory and in classical eleven-dimensional supergravity. In agreement with the results of Dine and Rajaraman, we find that these terms vanish in Matrix theory. We show that the absence of these terms is compatible with the classical supergravity theory when the theory is compactified in a lightlike direction, resolving an apparent discrepancy between the two theories. A brief discussion is given of how this calculation might be generalized to compare the Matrix theory and supergravity descriptions of an arbitrary 3-body system.
Cryptoprotocols: Subscription to a Public Key, The Secret Blocking and The Multi-Player Mental Poker Game (extended abstract)

Investigating the capabilities of public key and related cryptographic techniques has recently become an important area of cryptographic research. In this paper we present some new algorithms and cryptographic protocols (Cryptoprotocols) which enlarge the range of applications of public key systems and enable us to perform certain transactions in communication networks. The basic cryptographic tools used are Rabin’s Oblivious Transfer Protocol and an algorithm we developed for Number Embedding which is provably hard to invert.
Bilinear CNN Models for Fine-Grained Visual Recognition

We propose bilinear models, a recognition architecture that consists of two feature extractors whose outputs are multiplied using outer product at each location of the image and pooled to obtain an image descriptor. This architecture can model local pairwise feature interactions in a translationally invariant manner which is particularly useful for fine-grained categorization. It also generalizes various orderless texture descriptors such as the Fisher vector, VLAD and O2P. We present experiments with bilinear models where the feature extractors are based on convolutional neural networks. The bilinear form simplifies gradient computation and allows end-to-end training of both networks using image labels only. Using networks initialized from the ImageNet dataset followed by domain specific fine-tuning we obtain 84.1% accuracy of the CUB-200-2011 dataset requiring only category labels at training time. We present experiments and visualizations that analyze the effects of fine-tuning and the choice two networks on the speed and accuracy of the models. Results show that the architecture compares favorably to the existing state of the art on a number of fine-grained datasets while being substantially simpler and easier to train. Moreover, our most accurate model is fairly efficient running at 8 frames/sec on a NVIDIA Tesla K40 GPU. The source code for the complete system will be made available at http://vis-www.cs.umass.edu/bcnn.
Cumulative Advantage as a Mechanism for Inequality: A Review of Theoretical and Empirical Developments

Although originally developed by R.K. Merton to explain advancement in scientific careers, cumulative advantage is a general mechanism for inequality across any temporal process (e.g., life course, family generations) in which a favorable relative position becomes a resource that produces further relative gains. This review shows that the term cumulative advantage has developed multiple meanings in the sociological literature. We distinguish between these alternative forms, discuss mechanisms that have been proposed in the literature that may produce cumulative advantage, and review the empirical literature in the areas of education, careers, and related life course processes.
On the construction of prefix-free and fix-free codes with specified codeword compositions

We investigate the construction of prefix-free and fix-free codes with specified codeword compositions. We present a polynomial time algorithm which constructs a fix-free code with the same codeword compositions as a given code for a special class of codes called distinct codes. We consider the construction of optimal fix-free codes which minimize the average codeword cost for general letter costs with uniform distribution of the codewords and present an approximation algorithm to find a near optimal fix-free code with a given constant cost.
Anomalous heat conduction in polyethylene chains: Theory and molecular dynamics simulations

In 1955 Fermi, Pasta, and Ulam showed that a simple model for a nonlinear one-dimensional chain of particles can be nonergodic, which implied infinite thermal conductivity. A more recent investigation of a realistic model for an individual polyethylene chain suggests that this phenomenon can even persist in real polymer chains. The reason for the divergent behavior and its associated mechanism, however, remains unclear. This paper presents a general formulation for normal-mode vibrational contributions to thermal conductivity, which is then used to analyze molecular dynamics simulations of individual polyethylene chains. Our analysis shows that cross correlations for midfrequency longitudinal-acoustic phonons are responsible for the divergent thermal conductivity in our model.
Collisional Breakup of Particles in a Planetary Ring

Jeffreys (1947) estimated the size of fragments resulting from breakup of a satellite inside the Roche limit, obtaining a result of about 100 km. This result does not allow for the further breakup of the fragments due to collisions among themselves, which should reduce the maximum size to less than about 3 km for rock, or less than about 1 km for ice. This result affects not only Jeffreys' speculations as to the origin of Saturn's rings, but also recent speculations on the origin of the moon by capture and the possible tidal destruction of satellites of Mercury or Venus.
The synthesis of quaternary carbon centers through cyclialkylations

Abstract Treatment of conjugated dienone 1 with a strong Lewis acid at −78 °C produced a hydrophenanthrene with a newly created quaternary carbon. During this transformation the arene moiety becomes a dienone system.
Congressional Mobilization of Private Litigants: Evidence from the Civil Rights Act of 1991

Levels of private litigation enforcing statutes are critically determined by legislative choice. I set out a theoretical framework for understanding how legislators purposefully influence the potential economic value of statutory claims, thereby establishing a market for enforcement consistent with legislative preferences. To test the theory, I examine the effects of the Civil Rights Act (CRA) of 1991, which increased the value of employment discrimination claims under the CRA of 1964, and find that the law increased the number of claims filed. The origins and legislative history of the law also reveal that Congress utilized economic incentives as a policy instrument to purposefully increase private litigation, with a high degree of self-consciousness, in the course of conflict with other political actors over control of civil rights policy.
A dynamo theory prediction for solar cycle 22: Sunspot number, radio flux, exospheric temperature, and total density at 400 km

Using the 'dynamo theory' method to predict solar activity, a value for the smoothed sunspot number of 109 + or - 20 is obtained for solar cycle 22. The predicted cycle is expected to peak near December, 1990 + or - 1 year. Concommitantly, F(10.7) radio flux is expected to reach a smoothed value of 158 + or - 18 flux units. Global mean exospheric temperature is expected to reach 1060 + or - 50 K and global total average total thermospheric density at 400 km is expected to reach 4.3 x 10 to the -15th gm/cu cm + or - 25 percent.
Zipf distribution of U.S. firm sizes.

Analyses of firm sizes have historically used data that included limited samples of small firms, data typically described by lognormal distributions. Using data on the entire population of tax-paying firms in the United States, I show here that the Zipf distribution characterizes firm sizes: the probability a firm is larger than size s is inversely proportional to s. These results hold for data from multiple years and for various definitions of firm size.
Changes in Relative Wages, 1963–1987: Supply and Demand Factors

A simple supply and demand framework is used to analyze changes in the U. S. wage structure from 1963 to 1987. Rapid secular growth in the demand for more-educated workers, "more-skilled" workers, and females appears to be the driving force behind observed changes in the wage structure. Measured changes in the allocation of labor between industries and occupations strongly favored college graduates and females throughout the period. Movements in the college wage premium over this period appear to be strongly related to fluctuations in the rate of growth of the supply of college graduates.
Impact of the ocean acoustic transfer function on the coherence of undersea propagations

Multipath propagation, in conjunction with source motion, creates a splitting and spreading of the received source-signal energy over the time register time scale-factor (ambiguity) plane. This splitting of the received signal energy is manifested as correlation interactions between both; the set of eigenray signal arrivals (comprising the multipaths) at each receiving sensor, and the set of eigenray signal correlation pairs comprising two (or more) sensors. The more tightly the sets of eigenray signals are clustered in the ambiguity plane, the stronger will be the signal component interactions at each sensor and the less will be the expected correlation degradation between sensors. However, the greater will be the variance. Conversely, the more diffuse the clustering, the weaker will be the signal component interactions and the greater will be the expected intersensor coherence degradation. Also, the less will be the variance. Criteria which define the degree of signal component interactions in terms of the signal and the ocean transfer function parameters have been defined and are displayed in graphical form.
Conversation map: a content-based Usenet newsgroup browser

The Conversation Map system is a Usenet newsgroup browser that analyzes the text of an archive of newsgroup messages and outputs a graphical interface that can be used to search and read the messages of the archive. The system incorporates a series of novel text analysis procedures that automatically computes (1) a set of social networks detailing who is responding to and/or citing whom in the newsgroup; (2) a set of “discussion themes” that are frequently used in the newsgroup archive; and, (3) a set of semantic networks that represent the main terms under discussion and some of their relationships to one another. The text analysis procedures are written in the Perl programming language. Their results are recorded as HTML, and the HTML is displayed with a Java applet. With the Java-based graphical interface one can browse a set of Usenet newsgroup articles according to who is “talking” to whom, what they are “talking” about, and the central terms and possible emergent metaphors of the conversation. In this paper it is argued that the Conversation Map system is just one example of a new kind of content-based browser that will combine the analysis powers of computational linguistics with a graphical interface to allow network documents and messages to be viewed in ways not possible with today's, existing, format-based browsers which do not analyze the contents of the documents or messages.
Reconsidering Culture and Poverty

Culture is back on the poverty research agenda. Over the past decade, sociologists, demographers, and even economists have begun asking questions about the role of culture in many aspects of poverty and even explicitly explaining the behavior of the low-income population in reference to cultural factors. An example is Prudence Carter (2005), who, based on interviews with poor minority students, argues that whether poor children will work hard at school depends in part on their cultural beliefs about the differences between minorities and the majority. Annette Lareau (2003), after studying poor, working-class, and middleclass families, argues that poor children may do worse over their lifetimes in part because their parents are more committed to “natural growth” than “concerted cultivation” as their cultural model for child rearing. Mario Small (2004), based on fieldwork in a Boston housing complex, argues that poor people may be reluctant to participate in beneficial community activities in part because of how they culturally perceive their neighborhoods. David Harding (2007, 2010), using survey and qualitative interview data on adolescents, argues that the sexual behavior of poor teenagers depends in part on the extent of cultural heterogeneity in their neighborhoods. Economists George Akerlof and Rachel Kranton (2002), relying on the work of other scholars, argue that whether students invest in schooling depends in part on their cultural identity, wherein payoffs will differ among “jocks,” “nerds,” and “burnouts.” And William Julius Wilson, in his latest book (2009a), argues that culture helps explain how poor African Americans respond to the structural conditions they experience.
Were Money Wages Always Rigid? A Look at the Reliability of Survey Evidence on Changes in Wage Rates

In recent years, the once conventional view that nominal wage rates were much more flexible before the Great Depression than after has been challenged. This challenge has been reinforced by several recent studies that are based on monthly wage data gathered by state labor bureaus. The surveys used by the state labor bureaus in gathering the data appear to have been biased toward the finding that wages have not changed. Hence inferences drawn from the data collected in these surveys are not reliable.
Optimal Land Conversion at the Rural-Urban Fringe with Positive and Negative Agricultural Externalities

Bid-rent curves are incorporated in a stochastic dynamic programming model of land development around a city when farmland generates both positive and negative externalities. The model delineates how the quantities of land in various uses over time should depend on the relative social weights assigned to the competing agricultural externalities.
An improved method for direct conversion of heteroaryl-aldehydes to heteroaryl-acetonitriles

Abstract Treatment of heteroaryl-aldehydes with diethyl cyanophosphonate in the presence of a catalytic amount of LiCN affords phosphorylated cyanohydrins which are reduced in situ with SmI 2 to give heteroaryl-acetonitriles in generally good overall yields (50–100%). The generality of the process is demonstrated.
Examining risk attitudes

The existence of risky choices makes the study of attitudes toward risk important. In this article we ask the following questions: Do risk-neutral preferences maximize utility? Are there other measures of social welfare that can explain risk aversion in society? What effect does evolution have on the distribution of risk attitudes and the measures of social welfare? In a static environment risk-neutral risk attitudes maximize utilitarian measures of social welfare, and risk-averse attitudes maximize Rawlsian measures. In a dynamic system agents will tend toward risk, preferring greater affinity for risk when they can accumulate wealth.
THE CONCENTRATING ACTIVITY OF THE GALL BLADDER

The bile coming at one time from different portions of the liver of the dog has nearly the same amount of pigment per cubic centimeter. With this determined we have studied the power of the gall bladder to concentrate bile directed to it, using as criterion the pigment strength of a sample collected throughout the period of experiment from a duct branch. The extent and rapidity of the concentration are alike remarkable. A gall bladder emptied at the beginning of one experiment and left to fill from the liver, concentrated the 49.8 cc. of bile reaching it in 22½ hours to 4.6 cc., that is to say reduced its bulk 10.8 times; while another bladder left distended with a bile of known constitution and receiving in addition fresh increments from the liver concentrated the secretion 8.9 times in 22 hours. A series of five emptied bladders concentrated the bile coming to them in about 24 hours on the average 7.1 times, or a little more than the 6.4 times of seven organs left full. The conditions in both cases were relatively unfavorable to the withdrawal of fluid from the bile because this takes place by osmosis and diffusion, with the ultimate Δ always that of the blood, and the secretion in our animals was notably rich in solids as an indirect result of the operation. The rapidity with which fluid is withdrawn through the wall of the bladder may be judged from some experiments in which a bag was connected with the tip of the organ by a large cannula. Merely in its passage through the bladder the bile was concentrated 2.3 to 4.8 times. The finding indicates a potential source of error in observations upon samples of bile obtained from fistulous channels of which the bladder forms a part. The bile ducts do not withdraw fluid from the secretion they convey but tend to dilute it, as we shall show in a companion paper. The restriction of the concentrating activity to the receptaculum chyli is good evidence that the latter has special significance for the organism. The nature of this significance is briefly discussed.
Studying protein folding on the Grid: experiences using CHARMM on NPACI resources under Legion

One benefit of a computational Grid is the ability to run high-performance applications over distributed resources simply and securely. We demonstrated this benefit with an experiment in which we studied the protein-folding process with the CHARMM molecular simulation package over a Grid managed by Legion, a Grid operating system. High-performance applications can take advantage of Grid resources if the Grid operating system provides both low-level functionality as well as high-level services. We describe the nature of services provided by Legion for high-performance applications. Our experiences indicate that human factors continue to play a crucial role in the configuration of Grid resources, underlying resources can be problematic, Grid services must tolerate underlying problems or inform the user, and high-level services must continue to evolve to meet user requirements. Our experiment not only helped a scientist perform an important study, but also showed the viability of an integrated approach such as Legion's for managing a Grid. Copyright © 2004 John Wiley & Sons, Ltd.
The Captive King and His Captive Court: The Psychopolitical Dynamics of the Disabled Leader and His Inner Circle

Drawing on case material from recent and past history, this paper systematically examines the effects of leader disability on political decision making and behavior, giving special attention to the complex relationship between the disabled leader and his inner circle. Four groups of factors are examined: (1) factors related to the illness itself, including whether the illness is physical or mental, and whether the disability is temporary or preterminal, total or partial; (2) factors related to the leader and his reaction to his illness, including the degree to which the leader denies or acknowledges the extent of his disability; (3) factors related to the nature of the political system including whether the society is open or closed, and whether there is a clearly defined succession process; and (4) factors associated with the medical care of the VIP patient, including the conflict between the health needs of the individual and the political needs of the system. In a closed society, with a partially disab...
Dynamic stereo with self-calibration

An approach for incremental refinement of disparity maps obtained from a dynamic stereo sequence of a static scene is presented. The approach has been implemented using a binocular stereo vision system mounted on a mobile robot. A robust least median of squares based algorithm is given for recovering the camera motion between successive viewpoints, which provides a self-calibration mechanism. The recovered motion is utilized for recursive disparity prediction and refinement using a robust Kalman filter model. >
The political economy of American Indian gaming

Since the late 1980s, the commercial gaming industry has grown rapidly on American Indian reservations. Today, more than 200 Indian nations own more than 400 gaming operations in 28 states, yielding revenues in 2006 of more than $25 billion. How did this come about and what are the effects on Indian nations and on non-Native communities? The organization of contemporary Indian gaming operations has its roots in tribal-state conflicts dating to the late 1970s. It is a governmental activity, carried out by tribal governments on the basis of the preexisting rights of Indian nations, although it has been substantially constrained by congressional legislation and federal court decisions. While gaming's effects are unevenly distributed across tribes, its political, economic, and social impacts on many Indian reservations have been significant and positive, and it has had positive economic effects on many non-Native communities as well, particularly in distressed areas. But our understanding of gaming's effects ...
Online Pickup and Delivery Planning with Transfers for Mobile Robots

We have deployed a fleet of robots that pickup and deliver items requested by users in an office building. Users specify time windows in which the items should be picked up and delivered, and send in requests online. Our goal is to form a schedule which picks up and delivers the items as quickly as possible at the lowest cost. We introduce an auction-based scheduling algorithm which plans to transfer items between robots to make deliveries more efficiently. The algorithm can obey either hard or soft time constraints. We discuss how to replan in response to newly requested items, cancelled requests, delayed robots, and robot failures. We demonstrate the effectiveness of our approach through execution on robots, and examine the effect of transfers on large simulated problems.
Solid state deoximation with ammonium persulfate-silica gel: Regeneration of carbonyl compounds using microwaves

Abstract Ammonium persulfate on silica gel rapidly regenerates carbonyl compounds from their corresponding oxime derivatives using microwaves under solventless “dry” conditions.
[3,3]-Sigmatropic rearrangements: recent applications in the total synthesis of natural products.

Among the fundamental chemical transformations in organic synthesis, the [3,3]-sigmatropic rearrangement occupies a unique position as a powerful, reliable, and well-defined method for the stereoselective construction of carbon–carbon or carbon–heteroatom bonds. While many other reactions can unite two subunits and create a new bond, the strengths of sigmatropic rearrangements derive from their ability to enable structural reorganization with unmatched build-up of complexity. Recent applications that illustrate [3,3]-sigmatropic processes as a key concept in the synthesis of complex natural products are described in this tutorial review, covering literature from about 2001 through early 2009.
The host galaxies of fast-Ejecta core-collapse supernovae

Spectra of broad-lined Type Ic supernovae (SN Ic-BL), the only kind of SN observed at the locations of long-duration gamma-ray bursts (LGRBs), exhibit wide features indicative of high ejecta velocities ((is) approximately 0.1c). We study the host galaxies of a sample of 245 low-redshift (z (is) less than 0.2) core-collapse SN, including 17 SN Ic-BL, discovered by galaxy-untargeted searches, and 15 optically luminous and dust-obscured z (is) less than 1.2 LGRBs. We show that, in comparison with SDSS galaxies having similar stellar masses, the hosts of low-redshift SN Ic- BL and z (is) is less than 1.2 LGRBs have high stellar-mass and star-formation-rate densities. Core-collapse SN having typical ejecta velocities, in contrast, show no preference for such galaxies. Moreover, we find that the hosts of SN Ic-BL, unlike those of SN Ib/Ic and SN II, exhibit high gas velocity dispersions for their stellar masses. The patterns likely reflect variations among star-forming environments, and suggest that LGRBs can be used as probes of conditions in high-redshift galaxies. They may be caused by efficient formation of massive binary progenitors systems in densely star-forming regions, or, less probably, a higher fraction of stars created with the initial masses required for a SN Ic-BL or LGRB. Finally, we show that the preference of SN Ic-BL and LGRBs for galaxies with high stellar-mass and star-formation-rate densities cannot be attributed to a preference for low metal abundances but must reflect the influence of a separate environmental factor.
Topology, length scales, and energetics of surfactant micelles

We study the morphology, energetics, and kinetics of a self-associating model cationic surfactant in water using large-scale coarse-grained molecular dynamics simulations over time scales that allow for probing micelle recombination dynamics. We develop an algorithm to track micelle contours and quantify various microstructural features such as contour length distribution, persistence length, and mesh size. We predict reliably the end-cap energy and recombination time of micelles, directly from molecular simulations for the first time. We further consider the variation of solution viscosity as a function of salt concentration and show that branched and multiconnected structures govern the experimentally observed anomalous dependence of zero-shear viscosity on salt concentration. Overall, simulation predictions are in good agreement with experiments.
Synthesis of 3-Sulfenyl- and 3-Selenylindoles by the Pd/Cu-Catalyzed Coupling of N,N-Dialkyl-2-iodoanilines and Terminal Alkynes, Followed by n-Bu4NI-Induced Electrophilic Cyclization

3-Sulfenyl- and 3-selenylindoles are readily synthesized by a two-step process involving the palladium/copper-catalyzed crossing coupling of N,N-dialkyl-ortho-iodoanilines and terminal alkynes and subsequent electrophilic cyclization of the resulting N,N-dialkyl-ortho-(1-alkynyl)anilines with arylsulfenyl chlorides or arylselenyl chlorides. The presence of a stoichiometric amount of n-Bu4NI is crucial to the success of the electrophilic cyclization. A variety of 3-sulfenyl- and 3-selenylindole derivatives bearing alkyl, vinylic, aryl, and heteroaryl substituents have been prepared in good to excellent yields (up to 99%). By employing N,N-dibenzyl-ortho-iodoanilines, a 3-sulfenyl-N-H-indole has been successfully prepared. In addition, 3-sulfonyl- and 3-sulfinylindoles have also been successfully prepared by facile oxidation of the corresponding 3-sulfenylindoles.