cssi/SciSciGPT-SciSciNet huggingface dataset:
Machine learning enhancement of Storm Scale Ensemble precipitation forecasts

Precipitation forecasts provide both a crucial service for the general populace and a challenging forecasting problem due to the complex, multi-scale interactions required for precipitation formation. The Center for the Analysis and Prediction of Storms (CAPS) Storm Scale Ensemble Forecast (SSEF) system is a promising method of providing high-resolution forecasts of the intensity and uncertainty in precipitation forecasts. The SSEF incorporates multiple models with varied parameterization scheme combinations and produces forecasts every 4 km over the continental US. The SSEF precipitation forecasts exhibit significant negative biases and placement errors. In order to correct these issues, multiple machine learning algorithms have been applied to the SSEF precipitation forecasts to correct the forecasts using the NSSL National Mosaic and Multisensor QPE (NMQ) grid as verification. The 2010 SSEF was used for training. Two levels of post-processing are performed. In the first, probabilities of any precipitation are determined and used to find optimal thresholds for the precipitation areas. Then, three types of forecasts are produced in those areas. First, the probability of the 1-hour accumulated precipitation exceeding a threshold is predicted with random forests, logistic regression, and multivariate adaptive regression splines (MARS). Second, deterministic forecasts based on a correction from the ensemble mean are made with linear regression, random forests, and MARS. Third, fixed probability interval forecasts are made with quantile regressions and quantile regression forests. Models are generated from points sampled from the western, central, and eastern sections of the domain. Verification statistics and case study results show improvements in the reliability and skill of the forecasts compared to the original ensemble while controlling for the over-prediction of the precipitation areas and without sacrificing smaller scale details from the model runs.
Heterogeneous borrowers, liquidity, and the search for credit

Abstract We develop a general equilibrium model of credit formation where borrowers and lenders must search for matches and where the composition of borrowers adjusts to satisfy equilibrium entry conditions. When market liquidity dries up as a result of fundamental shocks to the system, fewer borrowers will participate in the credit market with low-quality borrowers suffering disproportionately because of a flight to quality. However, less liquid credit markets need not be associated with lower social output, because the effect of higher average quality may outweigh that of reduced market participation, depending crucially on the source of the liquidity shock.
A real-time computing system for LASA

The Large Aperture Seismic Array (LASA) consists of 525 vertical motion seismometers installed in an area of approximately 10,000 square miles in eastern Montana. Each seismometer is located at the bottom of a 200-foot borehole to reduce noise generated by wind, traffic, and livestock. The seismometers are grouped in clusters (subarrays) of 25 seismometers each, and the 21 subarrays are arranged in a series of successively inscribed squares (see Fig. 1) to produce a logarithmic density taper.
Finiteness properties of soluble arithmetic groups over global function fields

Let G be a Chevalley group scheme and B < G a Borel subgroup scheme, both defined over Z. Let K be a global function field, S be a finite non-empty set of places over K, and O S be the corresponding S-arithmetic ring. Then, the S-arithmetic group B(O S ) is of type F | S | - 1 but not of type FP | S | . Moreover one can derive lower and upper bounds for the geometric invariants Σ m (B(O S )). These are sharp if G has rank 1. For higher ranks, the estimates imply that normal subgroups of B(O S ) with abelian quotients, generically, satisfy strong finiteness conditions.
Tandem [4 + 2]/[3 + 2] Cycloadditions with Nitroethylene

The simplest nitroalkene, nitroethylene, undergoes Lewis acid-promoted [4 + 2] cycloaddition with chiral vinyl ethers to afford cyclic nitronates with high diastereoselectivity. The resulting cyclic nitronates react with electron deficient alkenes to effect a face selective [3 + 2] cycloaddition. The origin of stereocontrol in the [3 + 2] cycloaddition is due to the single ring substituent, a remote acetal center. The scope and limitations of the use of nitroethylene as a 4π component in Lewis acid-promoted cycloadditions are documented and discussed. Additionally, concise syntheses of the pyrrolizidine alkaloids (+)-macronecine and (+)-petasinecine are presented.
Intracluster Light in Nearby Galaxy Clusters: Relationship to the Halos of Brightest Cluster Galaxies

We present a detailed analysis of the surface brightness distribution of the brightest cluster galaxy (BCG) in each of 24 galaxy clusters at 0.03 < z < 0.13. We use two-dimensional profile fitting to model the surface brightness out to r = 300 kpc for each BCG, comparing r1/4, r1/n, and double r1/4 models. We obtain statistically superior fits using a two-component model consisting of a pair of r1/4 profiles with independent scale lengths, ellipticities, and orientations. The two-component model can simply reproduce the observed position angle and ellipticity gradients, which cannot generally be explained purely by triaxiality. The inner component of our two-component model has properties similar to those of a typical massive elliptical galaxy and is clearly associated with the BCG. The outer component is 10-40 times larger in scale, has ~10 times the total luminosity of the inner component, and exhibits a steeper μ-re relation than that of the elliptical fundamental plane. We interpret this outer component as a population of intracluster stars that trace the cluster potential. The two components are strongly aligned (|Δθ| < 10°) in roughly 40% of the clusters. When they are not aligned, the components tend toward high degrees of misalignment, suggesting that accretion of infalling material may change the orientation of some BCGs for a time. The extent of the outer component and its similar elongation to published cluster galaxy distributions indicates that the evolution of the intracluster light is tied to the cluster as a whole rather than to the BCG.
The bar-halo interaction-I. From fundamental dynamics to revised N-body requirements

A galaxy remains near equilibrium for most of its history. Only through resonances can nonaxisymmetric features such as spiral arms and bars exert torques over large scales and change the overall structure of the galaxy. In this paper, we descri be the resonant interaction mechanism in detail and derive explicit criteria for the particl e number required to simulate these dynamical processes accurately using N-body simulations, and illustrate them with numerical experiments. To do this, we perform a direct numerical solution of perturbation theory, in short, by solving for each orbit in an ensemble and make detailed comparisons with N-body simulations. The criteria include: sufficient particle cov erage in phase space near the resonance and enough particles to minimise gravitational potential fluctuations that will change the dynamics of the resonant encounter. These criteria are general in concept and can be applied to any dynamical interaction. We use the bar‐halo interaction as our primary example owing to its technical simplicity and astronomical ubiquity. Some of our more surprising findings are as follows. First, th e Inner-Lindblad-like resonance (ILR), responsible for coupling the bar to the central halo cusp, requires more than O(10 8 ) equal mass particles within the virial radius for a Milky-Way-like bar in an NFW profile (Navarro et al. 1997). Second, orbits that linger nea r the resonance receive more angular momentum than orbits that move through the resonance quickly. Small-scale fluctuations present in state-of-the-art particle-particle simulatio ns can knock orbits out of resonance, preventing them from lingering and, thereby, decrease the torque. This particularly affects the ILR. However, noise from orbiting substructure remains at least an order of magnitude too small to be of consequence. The required particle numbers are sufficiently high for scenarios of interest that apparent convergence in particle number is misleading: the convergence is in the noise-dominated regime. State-of-the-art simula tions are not adequate to follow all aspects of secular evolution driven by the bar-halo interac tion. It is not possible to derive particle number requirements that apply to all situations, e.g . more subtle interactions may be even more difficult to simulate. Therefore, we present a proc edure to test the requirements for individual N-body codes to the actual problem of interest.
Structure-Activity Studies on Tetrahydro- and Hexahydrocannabinol Derivatives

Abstract A series of tetrahydro- and hexahydrocannabinol derivatives was prepared in which the substituents at position 9 were varied. These compounds were evaluated in mice for their effects on locomotor activity, body temperature, muscle tone, and analgesia. Depression of body temperature and locomotor function was demonstrated by several compounds, but all were devoid of any significant analgesic activity.
Effect of β-Substituents on the Regioselectivity of the Diazomethane Ring Expansion of α-Methyl-α-methoxycyclobutanones to Cyclopentanones

The ring expansion of 22 differently β-substituted α-methyl-α-methoxycyclobutanones by diazomethane was studied. Migration of the less-substituted α-carbon was favored with the single exception of a very sterically hindered β-benzyloxy β-substituent.
Fixed-width output analysis for Markov chain Monte Carlo

Markov chain Monte Carlo is a method of producing a correlated sample to estimate features of a target distribution through ergodic averages. A fundamental question is when sampling should stop; that is, at what point the ergodic averages are good estimates of the desired quantities. We consider a method that stops the simulation when the width of a confidence interval based on an ergodic average is less than a user-specified value. Hence calculating a Monte Carlo standard error is a critical step in assessing the simulation output. We consider the regenerative simulation and batch means methods of estimating the variance of the asymptotic normal distribution. We give sufficient conditions for the strong consistency of both methods and investigate their finite-sample properties in various examples.
On homomorphisms between global Weyl modules

Global Weyl modules for generalized loop algebras $\lie g\tensor A$, where $\lie g$ is a simple finite dimensional Lie algebra and A is a commutative associative algebra were defined, for any dominant integral weight $\lambda$, by generators and relations. They are expected to play the role similar to that of Verma modules in the study of categories of representations of these algebras. One of the fundamental properties of Verma modules is that the space of morphisms between two Verma modules is either zero or one--dimensional and also that any non--zero morphism is injective. The aim of this paper is to establish an analogue of this property for the global Weyl modules. This is done under certain restrictions on the Lie algebra $\lie g$, $\lambda$ and $A$. A crucial tool is the construction of fundamental global Weyl modules in terms of fundamental local Weyl modules given in Section 3.
Compactifications of Hurwitz Spaces

We construct several modular compactifications of the Hurwitz space $H^d_{g/h}$ of genus $g$ curves expressed as $d$-sheeted, simply branched covers of genus $h$ curves. These compactifications are obtained by allowing the branch points of the covers to collide to a variable extent. They are very well-behaved if $d = 2, 3$, or if relatively few collisions are allowed. We recover as special cases the spaces of twisted admissible covers of Abramovich, Corti and Vistoli and the spaces of hyperelliptic curves of Fedorchuk.
On the rigidity of the coisotropic Maslov index on certain rational symplectic manifolds

We revisit the definition of the Maslov index of loops in coisotropic submanifolds tangent to the characteristic foliation of this submanifold. This Maslov index is given by the mean index of a certain symplectic path which is a lift of the holonomy along the loop. We prove a Maslov index rigidity result for stable coisotropic submanifolds in a broad class of ambient symplectic manifolds. Furthermore, we establish a nearby existence theorem for the same class of ambient manifolds.
Cs2CO3 promoted O-alkylation of alcohols for the preparation of mixed alkyl carbonates

Abstract The presence of cesium carbonate and tetrabutylammonium iodide (TBAI) facilitated efficient O -alkylation of alcohols with alkyl halides, giving rise to the exclusive formation of mixed alkyl carbonates. The cesium effect was also examined comparatively with other alkali carbonates.
A randomized trial of metronidazole in asymptomatic bacterial vaginosis to prevent the acquisition of sexually transmitted diseases.

Objective The purpose of this study was to determine whether treatment of bacterial vaginosis (BV) decreases the incidence of sexually transmitted diseases (STDs). Study Design Women with asymptomatic BV were studied prospectively to determine the effect of treatment of BV for the prevention of STD. Women were assigned randomly to observation or treatment and prophylaxis with intravaginal metronidazole gel. Women were screened monthly for STDs. Results Women who were assigned randomly to receive metronidazole gel had a significantly longer time to the development of STDs compared with women in the observation group (P = .02). The 6-month STD rate was 1.58 per person-year (95% CI, 1.29, 1.87) for women in the metronidazole gel group vs 2.29 per person-year (95% CI, 1.95, 2.63) for women in the observational group. The difference in STD rates was driven by a significant difference in the number of chlamydial infections (P = .013). Conclusion Treatment and twice-weekly prophylactic use of intravaginal metronidazole gel resulted in significantly fewer cases of chlamydia.
JKPLOT version 2.00: a device-independent plotting system written in QuickBasic for an IBM PC

Abstract Version 2.0 of JKPLOT is a simple, device-independent plotting system that can provide a base for building plotting facilities tailored to the needs of geologists. The programs were written in Microsoft QuickBasic for use on equipment compatible with an IBM personal computer. The system provides subroutines and functions for plotting in both 2 and 3 dimensions with the capability for making scaled plots with annotated axes. Plot output can be directed to the PC screen, an Epson printer, any HPGL pen plotter, or an HP laser printer. The user's documentation and program diskettes of the JKPLOT system are available from U.S. Geological Survey Open File Services.
Network coding for multiple unicasts: An interference alignment approach

This paper considers the problem of network coding for multiple unicast connections in networks represented by directed acyclic graphs. The concept of interference alignment, traditionally used in interference networks, is extended to analyze the performance of linear network coding in this setup and to provide a systematic code design approach. It is shown that, for a broad class of three-source three-destination unicast networks, a rate corresponding to half the individual source-destination min-cut is achievable via alignment strategies.
Sprinkler: Maximizing resource utilization in many-chip solid state disks

Resource utilization is one of the emerging problems in many-chip SSDs. In this paper, we propose Sprinkler, a novel device-level SSD controller, which targets maximizing resource utilization and achieving high performance without additional NAND flash chips. Specifically, Sprinkler relaxes parallelism dependency by scheduling I/O requests based on internal resource layout rather than the order imposed by the device-level queue. In addition, Sprinkler improves flash-level parallelism and reduces the number of transactions (i.e., improves transactionallocality) by over-committing flash memory requests to specific resources. Our extensive experimental evaluation using a cycle-accurate large-scale SSD simulation framework shows that a many-chip SSD equipped with our Sprinkler provides at least 56.6% shorter latency and 1.8 −2.2 times better throughput than the state-of-the-art SSD controllers. Further, it improves overall resource utilization by 68.8% under different I/O request patterns and provides, on average, 80.2% more flash-level parallelism by reducing half of the flash memory requests at runtime.
Sovereign risk assessment and agency credit ratings

Sovereign ratings are gaining importance as more governments with greater default risk borrow in international bond markets. However, while the ratings have proved useful to governments seeking market access, the difficulty of assessing sovereign risk has led to agency disagreements and public controversy over specific rating assignments. Recognising this difficulty, the financial markets have shown some scepticism toward sovereign ratings when pricing issues.
Large Area Self Assembled Tunable Terahertz Detector

To improve detector sensitivity, tunability and remove polarization dependence, we develop the gated grid plasmonic structure on 2DEG by using nanosphere self-assembly lithography. We obtain a large plasmonic resonance with a change in the transmission of 25%.
Highly enantioselective oxonium ylide formation and stevens rearrangement catalyzed by chiral Dirhodium(II) carboxamidates

Abstract 1,3-Dioxan-5-yl diazoacetates undergo conformation dependent oxonium ylide generation catalyzed by chiral dirhodium(II) carboxamidates, and Stevens rearrangement product(s) are formed with high chemoselectivity and with enantioselectivities reaching 88% ee.
Propagation of few-cycle pulses in nonlinear Kerr media: Harmonic generation

We apply the recently developed time-transformation technique to optical pulse propagation in nonlinear Kerr media, and to study carrier-wave shocking and generation of odd-order harmonics.
The synthesis of neoglycophospholipid conjugates via reductive amination of ω-oxoalkylglycosides and phosphatidylethanolamines

Abstract Phospholipid conjugates of mono- and disaccharides tethered with an n -decanyl spacer were efficiently synthesized via an improved reductive amination of deprotected ω -oxodecanyl β -glycosides and phosphatidylethanolamines with or without alkenyl groups. The ω -oxodecanyl β -glycosides were prepared by stereoselective glycosidation of glycosyl halides with 1,10-decanediol followed by pyridinium dichromate oxidation. The acetyl groups of the ω -oxodecanyl β -glycosides were removed with sodium methoxide prior to their conjugation with phosphatidylethanolamines.
Titanium silicide nanonet as a new material platform for advanced lithium ion battery applications.

Compared with competing technologies, rechargeable lithium ion batteries offer relative advantages such as high capacity and long cycle lifetime. Remarkable advances in the development of this technology notwithstanding significant performance improvements are still required to meet society's ever-growing electrical energy storage need. In particular, we long for devices with greater capacity, a higher power rate and a longer cycle lifetime. Aimed at solving challenges associated with poor charge transport within electrode materials, we have recently tested a new, nanonet-based material platform. The nanonet, made of TiSi2 (C49), is similar to the more commonly used porous carbon in that it has high surface area and good electrical conductivity. The key uniqueness of the nanonet lies in that its morphology is well-defined, permitting us to design and test various heteronanostructures. In essence, the TiSi2 nanonet can serve as a charge collector and a mechanical support for the construction of electrodes for a wide range of applications. We show that when combined with Si, an anode with superior performance is obtained. Similarly, a high-performance cathode is enabled by the TiSi2–V2O5 combination.
MeV Tau Neutrino:: Astrophysical and cosmological constraints and mischief

Terrestrial and “Heavenly” experiments severely constrain the mass and lifetime of an MeV tau neutrino. Irrespective of decay mode, for τv ≳ 300 sec the mass of the tau neutrino must be either approximately 30 MeV or less than 0.4 MeV (Majorana), 15 keV (Dirac). If the dominant decay mode includes electromagnetic daughter products, the mass must be less than 0.4 MeV (Majorana or Dirac) provided τv ≳ 2.5 × 10−12 sec, 15 keV (Dirac) provided τv ≳ 10−6 sec(mv/ MeV). A tau neutrino of mass between 1 MeV and 30 MeV can have a host of interesting astrophysical and cosmological consequences: relaxing the big-bang nucleosynthesis bound to the baryon density and the number of neutrino species, allowing big-bang nucleosynthesis to accommodate a low (less than 22%) 4 He mass fraction or high (greater than 10−4) deuterium abundance, improving significantly the agreement between the cold dark matter theory of structure formation and observations, and helping to explain how type II supernovae explode. Exploring the MeV mass range not only probes fundamental particle physics, but also interesting astrophysical and cosmological scenarios.
A Formal [4 + 4] Complementary Ambiphile Pairing Reaction: A New Cyclization Pathway for ortho-Quinone Methides

A formal, one-pot [4 + 4] cyclization pathway for the generation of eight-membered sultams via in situ generation of an ortho-quinone methide (o-QM) is reported. The pairing of ambiphilic synthons in a complementary fashion is examined whereby o-fluorobenzenesulfonamides are merged with in situ generated o-QM in a formal [4 + 4] cyclization pathway to afford 5,2,1-dibenzooxathiazocine-2,2-dioxide scaffolds under microwave (mW) conditions. The method reported represents the first use of an o-QM in a formal hetero [4 + 4] cyclization.
Ligand steric properties

Abstract Methods of estimating the steric requirements of ligands are reviewed. The most widely employed measure is the cone angle, ⊝, first proposed by Tolman. Elaborations on the cone angle concept include mathematical methods for its estimation, estimates based on X-ray structural data, and solid cone angle measures. The ligand repulsive parameter, E R , is based upon molecular mechanics calculations of the structures of Cr(CO) 5 complexes of the various ligands. The ⊝ and E R parameters correlate reasonably well, but significant disparities are found among a large group of phosphorus, arsenic and nitrogen ligands for which both ⊝ and E R , values are available. Consideration of the various approaches to estimating ligand steric requirements indicates that each ligand has a range of steric requirements relative to other ligands, depending on the details of the particular complex or reaction involved. Applications of ligand steric requirements include quantitative linear free energy relationships. Given the relative imprecision with which the steric (and probably also the electronic) parameters can be determined, the use of additional parameters to account for the relative importances of σ and π bonding, or the existence of a steric threshold may not be justified by the number and variety of data available. Nevertheless, despite their lack of high precision, linear free energy relationships can provide important information regarding the electronic and steric demands of the transition state relative to the ground state in chemical reactions.
Connected sum construction of constant Q-curvature manifolds in higher dimensions

Abstract For a compact Riemannian manifold ( M , g 2 ) with constant Q-curvature of dimension n ≥ 6 satisfying nondegeneracy condition, we show that one can construct many examples of constant Q-curvature manifolds by gluing construction. We provide a general procedure of gluing together ( M , g 2 ) with any compact manifold ( N , g 1 ) satisfying a geometric assumption. In particular, we can prove that there exists a metric with constant Q-curvature on the connected sum N#M.
The sign representation for shephard groups

Shephard groups are unitary reflection groups arising as the symmetries of regular complex polytopes. For a Shephard group, we identify the representation carried by the principal ideal in the coinvariant algebra generated by the image of the product of all linear forms defining reflecting hyperplanes. This representation turns out to have many equivalent guises making it analogous to the sign representation of a finite Coxeter group. One of these guises is (up to a twist) the cohomology of the Milnor fiber for the isolated singularity at \(0\) in the hypersurface defined by any homogeneous invariant of minimal degree.
Bacteriophage-based synthetic biology for the study of infectious diseases

Since their discovery, bacteriophages have contributed enormously to our understanding of molecular biology as model systems. Furthermore, bacteriophages have provided many tools that have advanced the fields of genetic engineering and synthetic biology. Here, we discuss bacteriophage-based technologies and their application to the study of infectious diseases. New strategies for engineering genomes have the potential to accelerate the design of novel phages as therapies, diagnostics, and tools. Though almost a century has elapsed since their discovery, bacteriophages continue to have a major impact on modern biological sciences, especially with the growth of multidrug-resistant bacteria and interest in the microbiome.
The Effect of Merger Boosts on the Luminosity, Temperature, and Inferred Mass Functions of Clusters of Galaxies

In the standard cold dark matter model of structure formation, massive clusters form via the merger of smaller clusters. N-body/hydrodynamical simulations of merging galaxy clusters have shown that mergers can temporarily boost the X-ray luminosity and temperature of the merged cluster above the equilibrium values for the merged system. The cumulative effect of these "merger boosts" will affect the observed X-ray luminosity functions (XLFs) and temperature functions (TFs) of clusters. One expects this effect to be most important for the most luminous and hottest clusters. XLFs and TFs of clusters provide some of the strongest constraints on cosmological and large-scale structure parameters, such as the mean fluctuation parameter σ8 and the matter density divided by the critical density Ω0. Merger boosts may bias the values of σ8 and Ω0 inferred from cluster XLFs and TFs if virial equilibrium is assumed. We use a semianalytic technique to estimate the effect of merger boosts on the XLFs and TFs. The boosts from individual mergers are derived from N-body/hydrodynamical simulations of mergers. The statistics of the merger histories of clusters are determined from extended Press-Schechter (PS) merger trees. We find that merger boosts can increase the apparent number of hot, luminous clusters. For example, in a universe with Ω0 = 0.3 and ΩΛ = 0.7 at a redshift of z = 1, the number of clusters with temperatures T > 10 keV is increased by a factor of 9.5, and the number of clusters with luminosities LX > 5 × 1044 h-2 ergs s-1 is increased by a factor of 8.9. We have used our merger-boosted TFs and XLFs to derive the cosmological structure parameters σ8 and Ω0 by fitting PS equilibrium relations to local (z = 0) and distant (either z = 0.5 or z = 1) cluster samples. Merger boosts cause σ8 to be overestimated by about 20%. The matter density parameter Ω0 may be underestimated by about 20%, although this result is less clear. If the parameters of the fluctuation spectrum are derived from the observed TF or XLF (e.g., from a low-redshift sample), then this removes most of the boost effect on Ω0. However, larger merger boost effects may appear when cluster XLFs and TFs are compared to cosmological structure parameters derived by other techniques (e.g., cosmic microwave background fluctuations or the brightness of distant supernovae).
Bilayer formation in metal carboxylate structures: results from the Cambridge Structural Database

Abstract The crystal structures of 272 metal carboxylates were surveyed with regard to the prevalence of bilayer formation. Bilayers affect the chemical and physical properties of solids. In particular, solid-state reactivity may be greatly enhanced by the presence of 2-dimensional metal coordination polymers in a bilayer motif. Bilayer formation is common (≈60% of 2-D coordination polymers) for aliphatic 3-carbon acidate salts and complexes, and is dominant (92%) for salts and complexes of ≥4-carbon aliphatic acids. For aromatic unsubstituted acids, the percentage is remarkably low (32% of all structures in the class—most are 1-D coordination polymers), while addition of a spacer group between the carboxyl group and the aromatic portion leads to >90% bilayer/2-D coordination polymer formation. The above points and other subtle features are illustrated in this contribution, and strategies for planning the production of possible bilayer materials are proposed.
Retrocardiac Herniation of Atelectatic Lung Into the Opposite Chest

A 64-year-old man with a history of esophageal adenocarcinoma status postneoadjuvant therapy underwent esophagogastrectomy. Postoperatively he was found with increasing dyspnea and oxygen requirements. Computed tomography of the chest showed retrocardiac herniation of atelectatic lung into the contralateral hemithorax.
The Security Council: Adapting to Address Contemporary Conflict

Throughout the 1990s, with the post-Cold War era as backdrop, there have been numerous changes in the approach of the United Nations Security Council to conflict between and within nations. The author, using historical incidents for illustration, highlights such topics as the changing nature of conflicts addressed by the Council; consideration during Council decision making; developments within the United Nations itself (“institutional”); the cumulative impact of Security Council decision making; and key challenges facing the Council today and in the future.
Costal Cartilage Excision for the Treatment of Pediatric Slipping Rib Syndrome

Abstract Background Costal cartilage excision is an effective treatment of slipping rib syndrome (SRS), although the diagnosis of SRS may be elusive. We review our experience with SRS in the pediatric patient. Methods This is a retrospective review from 2000 to 2011 of patients presenting with symptoms of SRS before 18 years of age. Results Seven patients were identified who were diagnosed with SRS and underwent costal cartilage excision. All patients presented with unilateral chest pain that was exacerbated by activity. Five patients reported a popping or clicking sensation with activity that was associated with pain. On physical examination, all patients had reproducible pain with palpation over the affected cartilage. Four patients had a mobile or popping rib with palpation, and 4 also had chest wall asymmetry. Five patients underwent imaging, and 4 patients were referred to specialists. It was a median of 2 years (0-5 years) from onset of symptoms to resection. At resection, all cartilages were grossly abnormal. There were no postoperative complications. Follow-up was complete for all patients over a median 0.9 years (0.2-2.0 years). One patient had recurrence of pain in a different location; another had persistent pain, which was less severe. Conclusions Slipping rib syndrome presents with costal cartilage pain that is reproducible on physical examination and commonly associated with a mobile rib. Excision of the affected cartilage(s) is an effective treatment and should be considered early to avoid unnecessary diagnostic tests and evaluation, which delay definitive therapy.
Using Heteroskedasticity to Identify and Estimate Mismeasured and Endogenous Regressor Models

This article proposes a new method of obtaining identification in mismeasured regressor models, triangular systems, and simultaneous equation systems. The method may be used in applications where other sources of identification, such as instrumental variables or repeated measurements, are not available. Associated estimators take the form of two-stage least squares or generalized method of moments. Identification comes from a heteroscedastic covariance restriction that is shown to be a feature of many models of endogeneity or mismeasurement. Identification is also obtained for semiparametric partly linear models, and associated estimators are provided. Set identification bounds are derived for cases where point-identifying assumptions fail to hold. An empirical application estimating Engel curves is provided.
Quasars as Absorption Probes of the J0053+1234 Region

We present UBRI photometry and spectra for 60 quasars found within 1 deg2 centered on the J0053+1234 region, which has been the subject of the Caltech Faint Galaxy Redshift Survey. Candidate quasars were selected by their ultraviolet excess with respect to the stellar locus and confirmed spectroscopically. The quasars span a wide range in brightness (17.5 < B < 21.6) and redshift (0.43 < z < 2.38). These new quasars comprise a grid of absorption probes that can be used to study large-scale structure, as well as the correlation between luminous galaxies, nonluminous halos, and Lyα absorbers in the direction of the deep pencil-beam galaxy survey. Spectra of 14 emission-line galaxies found using the same technique are also presented.
Exploiting the divalent nature of isonitriles: a novel Pictet–Spengler amidination process

An isocyanide-based multicomponent reaction (IMCR) utilized for the rapid assembly of novel, biologically relevant dihydropyrrolo[1,2-a]quinoxalines-amidines is herein presented. Starting from 1-(2-aminophenyl)pyrroles, aldehydes, and isonitriles, the target heterocyclic scaffold is assembled in a one-pot, operationally friendly process. With three points of diversity and formation of three chemical bonds in one step, this strategy proves to be very general. Novel, mild methodology for the generation of amidines from secondary amine anilines and isonitriles is also introduced.
Modeling flow and transport in unsaturated fractured rock: an evaluation of the continuum approach.

Abstract Because the continuum approach is relatively simple and straightforward to implement, it has been commonly used in modeling flow and transport in unsaturated fractured rock. However, the usefulness of this approach can be questioned in terms of its adequacy for representing fingering flow and transport in unsaturated fractured rock. The continuum approach thus needs to be evaluated carefully by comparing simulation results with field observations directly related to unsaturated flow and transport processes. This paper reports on such an evaluation, based on a combination of model calibration and prediction, using data from an infiltration test carried out in a densely fractured rock within the unsaturated zone of Yucca Mountain, Nevada. Comparisons between experimental and modeling results show that the continuum approach may be able to capture important features of flow and transport processes observed from the test. The modeling results also show that matrix diffusion may have a significant effect on the overall transport behavior in unsaturated fractured rocks, which can be used to estimate effective fracture–matrix interface areas based on tracer transport data. While more theoretical, numerical, and experimental studies are needed to provide a conclusive evaluation, this study suggests that the continuum approach is useful for modeling flow and transport in unsaturated, densely fractured rock.
Mucin glycosylation is altered by pro-inflammatory signaling in pancreatic-cancer cells.

Altered glycosylation on the surfaces or secreted proteins of tumor cells is common in pancreatic cancer and is thought to promote cancer progression, but the factors leading to the changes in carbohydrate structures are incompletely understood. We hypothesized that pro-inflammatory conditions can lead to alterations in cancer-associated glycans on mucins produced by pancreatic-cancer cells. With the use of a novel antibody-glycan microarray method, we measured the effects of pro-inflammatory stimuli (oxidative stress and treatment with the cytokines IFNγ, IL-1α, and TNFα) on the expression and glycosylation of the mucins MUC1, MUC5AC, and MUC16 in multiple pancreatic cancer cell lines. Mucin glycosylation was significantly affected in specific cell lines, particularly in structures involving terminal galactose or N-acetylgalactosamine. In addition, the responses of the cell lines grouped according to the expression of cell-surface markers that are associated with tumorigenicity, as cell lines bearing min...
Reconsidering the Divergence between Elderly, Child, and Overall Poverty

This study challenges the conventional wisdom that elderly, child, and overall poverty are divergent. Comparing the official U.S. measure with the Luxembourg Income Study’s (LIS) measure, the autho...
Breaking halo occupation degeneracies with marked statistics

We show that a suitably defined marked correlation function can be used to break degeneracies in halo-occupation distribution modelling. The statistic can be computed on both three-dimensional and two-dimensional data sets and should be applicable to all upcoming galaxy surveys. A proof of principle, using mock catalogues created from N-body simulations, is given.
Right-Handed New Physics Remains Strangely Beautiful

Current data on CP violation in B_d -> eta' K_S and B_d -> phi K_S, taken literally, suggest new physics contributions in b -> s transitions. Despite a claim to the contrary, we point out that right-handed operators with a single weak phase can account for both deviations thanks to the two-fold ambiguity in the extraction of the weak phase from the corresponding CP-asymmetry. This observation is welcome since large mixing in the right-handed sector is favored by many GUT models and frameworks which address the flavor puzzle. There are also interesting correlations with the B_s system which provide a way to test this scenario in the near future.
AutoWitness: Locating and tracking stolen property while tolerating GPS and radio outages

We present AutoWitness, a system to deter, detect, and track personal property theft, improve historically dismal stolen property recovery rates, and disrupt stolen property distribution networks. A property owner embeds a small tag inside the asset to be protected, where the tag lies dormant until it detects vehicular movement. Once moved, the tag uses inertial sensor-based dead reckoning to estimate position changes, but to reduce integration errors, the relative position is reset whenever the sensors indicate the vehicle has stopped. The sequence of movements, stops, and turns are logged in compact form and eventually transferred to a server using a cellular modem after both sufficient time has passed (to avoid detection) and RF power is detectable (hinting cellular access may be available). Eventually, the trajectory data are sent to a server which attempts to match a path to the observations. The algorithm uses a Hidden Markov Model of city streets and Viterbi decoding to estimate the most likely path. The proposed design leverages low-power radios and inertial sensors, is immune to intransit cloaking, and supports post hoc path reconstruction. Our prototype demonstrates technical viability of the design; the volume market forces driving machine-to-machine communications will soon make the design economically viable.
Mechanistic Investigation of a Novel Vitamin B12-Catalyzed Carbon−Carbon Bond Forming Reaction, the Reductive Dimerization of Arylalkenes

In the presence of catalytic vitamin B(12) and a reducing agent such as Ti(III)citrate or Zn, arylalkenes are dimerized with unusual regioselectivity forming a carbon [bond] carbon bond between the benzylic carbons of each coupling partner. Dimerization products were obtained in good to excellent yields for mono- and 1,1-disubstituted alkenes. Dienes containing one aryl alkene underwent intramolecular cyclization in good yields. However, 1,2-disubstituted and trisubstituted alkenes were unreactive. Mechanistic investigations using radical traps suggest the involvement of benzylic radicals, and the lack of diastereoselectivity in the product distribution is consistent with dimerization of two such reactive intermediates. A strong reducing agent is required for the reaction and fulfills two roles. It returns the Co(II) form of the catalyst generated after the reaction to the active Co(I) state, and by removing Co(II) it also prevents the nonproductive recombination of alkyl radicals with cob(II)alamin. The mechanism of the formation of benzylic radicals from arylalkenes and cob(I)alamin poses an interesting problem. The results with a one-electron transfer probe indicate that radical generation is not likely to involve an electron transfer. Several alternative mechanisms are discussed.
Web-based resources for retrieving health policy information: NLM and beyond.

This paper identifies Web-based resources of interest to the health policy community. Both information useful for developing health policy and information about existing health policy are included. Resources described are classified into three major categories: traditional and grey literature, statistical and epidemiological data, and legal and legislative material. National Library of Medicine (NLM) resources include MEDLINE, DIRLINE, HealthSTAR, HSRProj, and HSTAT. In addition, NLM's National Information Center on Health Services Research and Health Care Technology (NICHSR) has a Web page (http://www.nlm.nih.gov/nichsr/nichsr.html) that provides an extensive listing of health-policy-related Web sites. Some of the other resources highlighted include those available from the Health Care Financing Administration (HCFA), the National Center for Health Statistics (NCHS) of the Centers for Disease Control and Prevention (CDC), the National Committee for Vital and Health Statistics (NCVHS), and the Library of Congress.
The Challenge of Change: Rethinking Alcohol Abuse

Nurses usually conceptualize alcohol abuse and dependence as a progressive disease that can be managed but never cured. Yet there are millions of Americans for whom this approach is not helpful. Impressive results have been reported by the alcohol research community with interventions that are guided by the assumption that many alcohol problems are learned habits that can be changed. This article reviews the clinical research in the area of brief interventions and moderation training with alcohol abusers. Nursing's vital role in advocating for and delivering such interventions is identified. Resistance to implementing alternative approaches for the treatment of alcohol problems is explored.
On radiative CP violation in (supersymmetric) two Higgs doublet models

Abstract We discuss the feasibility of spontaneous CP violation being induced by radiative corrections in 2HDM's, emphasizing on a consistent treatment at 1-loop level. Specifically, we analyze the cases of gaugino/higgsino effect on MSSM, and a new model proposed here with an extra, exotic, quark doublet. The latter model is phenomenologically interesting. One conclusion is that some fine tuning is in general needed for the scenario to work. The case for the new model requires a tree level mass mixing between the two Higgses, which fits in the standard SUSY picture. The fine tuning requires is then very moderate in magnitude and in a way natural.
Quantitative investigation of acoustic streaming in blood

Acoustic streaming may have practical utility in diagnostic medical ultrasound in distinguishing between stagnant blood and tissue as well as clotted and unclotted blood. This distinction can be difficult with conventional ultrasound but have high value in managing trauma patients with internal hemorrhage. Ultrasound energy applies a force to blood by momentum transfer, resulting in bulk streaming that is a function of the acoustic attenuation, sound speed, acoustic intensity, blood viscosity, and the boundary conditions posed by the geometry around the hematoma. A simple tubular model was studied analytically, by finite element simulation, and experimentally by in vitro measurement. The simulation agreed closely with measurements while the analytic solutions were found to be valid only for beam diameters approximating the diameter of the tubular channel. Experimentally, the acoustic streaming in blood decreased as the blood began to clot and the streaming flow was not detected in clotted blood. In contrast, the echogenicity of the same blood samples did not change appreciably from the unclotted to the clotted state for the stagnant blood studied. Streaming detection appears to offer a potential tool for improving hemorrhage diagnosis.
Novel routes to 4-substituted N,N-dialkylanilines, N-alkylanilines and anilines

Abstract 4-(Benzotriazol-1-ylmethyl)-N,N-dialkylanilines, -N-alkylanilines, -anilines and some substituted analogs obtained via lithiation are converted by lithium aluminum hydride or Grignard reagents into 4-substituted N,N-dialkylanilines, N-alkylanilines and anilines, respectively, in good yields.
Identification of Minimum Air Flow Design for a Desktop Computer Using CFD Modeling

This paper reports the results of CFD analysis to cool the 30-W socketed CPU of a desktop computer with minimum air flow rate and minimum heat sink size. This was achieved using only the fan in the power supply for all air movement in the chassis. A duct was employed to direct the air flow over the CPU and then to the inlet air vents of the power supply. Use of this duct allowed more than 10/spl deg/C reduction of the CPU case temperature, relative to a unducted design. The CFD analysis results were confirmed by experiment, and the predicted CPU case temperatures agreed within /spl plusmn/2.9/spl deg/C of the experimental values for the ducted cases. This paper describes the methodology of CFD analysis for the heat sink/duct design, and describes experimental procedures to validate the predictions.
Young's Double-Slit Interferometry within an Atom

An experiment is described which is an analog of Young's double-slit interferometer using an atomic electron instead of light. Two phase-coherent laser pulses are used to excite a single electron into a state of the form of a pair of Rydberg wave packets that are initially on opposite sides of the orbit. The two wave packets propagate and spread until they completely overlap, then a third phase-coherent laser pulse probes the resulting fringe pattern. The relative phase of the two wave packets is varied so that the interference produces a single localized electron wave packet on one side of the orbit or the other.
An econometric analysis of the forward premium in the international corn market.

This study investigates the linkage between world macroeconomic factors and prices of an internationally traded commodity by explicitly accounting for the role of futures markets in stockholding behavior. Using a portfolio model, the empirical analysis is carried out with quarterly data of a storable, international traded commodity--corn--for the 1973I-1983IV period. The empirical findings show that a substantial variation in the corn forward premium can be explained by current and expected future values of macroeconomic variables, such as industrial production, interest rates, and exchange rates. Copyright 1990 by Oxford University Press.
Capital income taxation and economic growth in open economies

Can reductions in domestic capital income taxes attract foreign capital and, at the same time, foster economic growth? Using a two-country overlapping generations model with endogenous growth and internationally mobile capital, this paper shows that the effect of domestic capital taxes on the international allocation of capital and on the rate of economic growth do not necessarily go in the same direction. A country can attract capital by reducing its taxes, but this may lower the rate of economic growth depending on the elasticity of saving to the net-of-tax interest rate and on the effect of taxes on domestic factor productivity.