cssi/SciSciGPT-SciSciNet huggingface dataset:
Managing Varicoceles in Children: Results With Microsurgical Varicocelectomy

Authors from New York present their experience of elective varicocelectomy, using microsurgical techniques, in a large series of children. They found the procedure to be safe and effective, and gave a much lower complication rate than the published rate in open varicocelectomy. The results of urethroplasty in post-traumatic paediatric urethral strictures are presented by authors from Mansoura. They found the overall success of one-stage perineal anastomotic repair of such strictures to be excellent, with very little morbidity. OBJECTIVE To report our experience of microsurgical subinguinal varicocelectomy in boys aged ≤ 18 years. PATIENTS AND METHODS Boys aged ≤ 18 years treated with microsurgical varicocelectomy between 1996 and 2000 at one institution were retrospectively reviewed. Indications for surgery included ipsilateral testicular atrophy, large varicocele or pain. Microsurgery was assisted by an operating microscope (×10–25) allowing preservation of the lymphatics, and the testicular and cremasteric arteries. Patient age, varicocele grade, complications and follow-up interval were recorded. RESULTS In all there were 97 microsurgical subinguinal varicocelectomies (23 bilateral) in 74 boys (mean age 14.7 years). Left-sided varicoceles were significantly larger (mean grade 2.9) than right-sided (mean grade 1.4) varicoceles. The mean follow-up was 9.6 months. There were four complications: two hydroceles, of which one resolved spontaneously after 4 months; one patient had persistent orchialgia that resolved after 8 months; and one developed hypertrophic scarring at the inguinal incision site. There were no infections, haematomas or intraoperative injuries to the vas deferens or testicular arteries. All boys were discharged home on the day of surgery. CONCLUSIONS Microsurgical subinguinal varicocelectomy in boys is a safe, minimally invasive and effective means of treating varicoceles. Compared with published results of the retroperitoneal mass ligation technique, which has a 15% overall complication rate and a 7–9% hydrocele occurrence rate, the microsurgical subinguinal approach appears to offer less morbidity, with a 1% hydrocele rate. We consider that microsurgical subinguinal varicocelectomy offers the best results with lower morbidity than other techniques.
Rapid weakening of subducting plates from trench-parallel estimates of flexural rigidity

Abstract The negative buoyancy force of sinking lithosphere (slabs) is the principle driving force for subducting plates, but transmission of this force to the subducting plate depends on the strength of the slab (e.g., Conrad and Hager, 2001 ). Slab strength has been studied in the context of plate bending within subduction zones for a wide range of rheologies (i.e., perfectly elastic, perfectly viscous, perfectly plastic, brittle-ductile layered). Because the applicability of these rheologic models cannot be distinguished based on trench-perpendicular plate bending models ( Forsyth, 1980 ), a method was developed to directly measure variations in plate strength with distance from the trench and has found significant plate weakening within 100 km of the Kermadec Trench ( Billen and Gurnis, 2005 ). Using the same method we show that rapid plate weakening trenchward of the forebulge also exists at the Tonga and Japan-Izu-Bonin subduction zones. The observed plate weakening provides further evidence for a plate rheology that leads to significant yielding (loss of elastic strength and reduction in effective viscosity) within the bending region of the subducting plate. This rapid weakening within the shallow, low curvature, region of the plate may significantly decrease estimates of energy dissipation related to plate bending, compared to recent calculations assuming high plate strength and constant plate curvature.
Optimum Transmission Policies for Battery Limited Energy Harvesting Nodes

Wireless networks with energy harvesting battery equipped nodes are quickly emerging as a viable option for future wireless networks with extended lifetime. Equally important to their counterpart in the design of energy harvesting radios are the design principles that this new networking paradigm calls for. In particular, unlike wireless networks considered to date, the energy replenishment process and the storage constraints of the rechargeable batteries need to be taken into account in designing efficient transmission strategies. In this work, such transmission policies for rechargeable nodes are considered, and optimum solutions for two related problems are identified. Specifically, the transmission policy that maximizes the short term throughput, i.e., the amount of data transmitted in a finite time horizon is found. In addition, the relation of this optimization problem to another, namely, the minimization of the transmission completion time for a given amount of data is demonstrated, which leads to the solution of the latter as well. The optimum transmission policies are identified under the constraints on energy causality, i.e., energy replenishment process, as well as the energy storage, i.e., battery capacity. For battery replenishment, a model with discrete packets of energy arrivals is considered. The necessary conditions that the throughput-optimal allocation satisfies are derived, and then the algorithm that finds the optimal transmission policy with respect to the short-term throughput and the minimum transmission completion time is given. Numerical results are presented to confirm the analytical findings.
Expanding our students' brainpower: idea generation and critical thinking skills

How do we teach our students to think? This is not a skill that they can pick up by doing "X" number of homework problems; it is the product of good habits that must be practiced and honed on a daily basis. It is a state of mind that continually questions "Who? What? Where? When? How? Why?" In light of this reality, we developed this segment for the "Introduction to Literature Review and Proposal Writing" graduate course this past summer. Our goals during this three-day class period were: /spl middot/ To define the creative process /spl middot/ To identify techniques that enhance creativity /spl middot/ To practice idea generation and critical thinking skills in controlled settings This segment helps smooth the transition between the undergraduate mentality of "teach me" to the desired graduate-student mentality of "enable me." It attempts to demystify the creative process, which most people associate with inspired moments and geniuses, so that students can deliberately foster an atmosphere that will help them generate new research ideas.
Copper-catalyzed arylation of 1H-perfluoroalkanes.

A general method has been developed for arylation of readily available 1H-perfluoroalkanes. The method employs aryl iodide and 1H-perfluoroalkane reagents, DMPU solvent, TMP2Zn base, and a copper chloride/phenanthroline catalyst. Preliminary mechanistic studies are reported.
AIDS: politics and science.

Ethicists sometimes embark on an approach to thorny issues with the assertion that "good data make good ethics"; the same could be said of good politics. The burgeoning problems posed by the acquired immunodeficiency syndrome (AIDS) epidemic will put social systems and political skills to a severe test, but in the six years since the first cases of AIDS were diagnosed, biomedical and epidemiologic scientists have established a firm foundation of data on which to construct focused public health programs responsive to the precise contours of the epidemic. Meanwhile, the hazards of overreaction are becoming very clear. The good news . . .
Nitrate as a redox co-catalyst for the aerobic Pd-catalyzed oxidation of unactivated sp3-C–H bonds

This paper describes a new method for the catalytic aerobic oxygenation of unactivated sp3-C–H bonds. This transformation utilizes Pd(OAc)2 as a catalyst in conjunction with NaNO3 as a redox co-catalyst. Both oxime ether and pyridine derivatives are effective directing groups for these reactions. The oxygen incorporated into the product derives from the solvent (acetic acid). Preliminary results show that the addition of simple NaCl to the reaction mixture results in aerobic chlorination under analogous conditions.
Density of states in a resonant-tunneling structure

ABSTRACTS DISTRIBUTION LIST, 056/625/629Dr. J. E. Jensen Dr. C. B. HarrisHughes Research Laboratory Department of Chemistry3011 Malibu Canyon Road University of CaliforniaMalibu, California 90265 Berkeley, California 94720Dr. J. H. WeaverDepartment of Chemical Engineering Dr. F. Kutzlerand Materials Science Department of ChemistryUniversity of Minnesota Box 5055Minneapolis, Minnesota 55455 Tennessee Technological UniversityCookesville, Tennessee 38501Dr. A. ReismanMicroelectronics Center of North Carolina Dr. 0. DiLellaResearch Triangle Park, North Carolina Chemistry Department27709 George Washington UniversityWashington D.C. 20052Dr. M. GrunzeLaboratory for Surface Science and Dr. R. ReevesTechnology Chemistry DepartmentUniversity of Maine Renssaeler Polytechnic InstituteOrono, Maine 04469 Troy, New York 12181Dr. J. Butler Dr. Steven M. GeorgeNaval Research Laboratory Stanford UniversityCode 6115 Department of ChemistryWashington D.C. 20375-5000 Stanford, CA 94305Dr. L. Interante Dr. Mark JohnsonChemistry Department Yale UniversityRensselaer Polytechnic Institute Department of ChemistryTroy, New York 12181 New Haven, CT 06511-8118Dr. Irvin Heard Dr. W. KnauerChemistry and Physics Department Hughes Research LaboratoryLincoln University 3011 Malibu Canyon RoadLincoln University, Pennsylvania 19352 Malibu, California 90265Dr. K.J. KlaubundeDepartment of ChemistryKansas State UniversityManhattan, Kansas 665066
Coffee and Conflict in Colombia, 1886-1910

The appearance of Coffee and Conflict in Colombia, 1886-1910 , had several important consequences for the entire field of Latin American history, as well as for the study of Colombia. Through Bergquist's analysis of this transitional period in terms of what has been called the dependency theory, he has left his mark on all subsequent studies in Latin American affairs; questions of economic development and political alignment cannot be dealt with without confronting Bergquist's work. he has also provided a major contribution to Colombian history by his examination of the growth of the coffee industry and Thousand Days War.
Towards a tandem-radical macrocyclization-transannular cyclization approach to steroids: Transannular cyclizations of a macrocyclic core

Abstract The triple transannular radical cyclization of 1-cyano-5-methyl-1-phenylseleno-8-hydroxy-4,9,13-cycloheptadecatriene (1a) provided a product 2 possessing the steroid ring skeleton of unassigned configuration in 4% isolated yield. A high yielding transannular cyclization of the related diene lacking the Δ4,5double bond identifies the second cyclization as the Achilles heel of the triene cyclization.
Averaged periodogram spectral estimation with long-memory conditional heteroscedasticity

The empirical relevance of long-memory conditional heteroscedasticity has emerged in a variety of studies of long time series of high frequency financial measurements. A reassessment of the applicability of existing semiparametric frequency domain tools for the analysis of time dependence and long-run behaviour of time series is therefore warranted. To that end, in this paper the averaged periodogram statistic is analysed in the framework of a generalized linear process with long-memory conditional heteroscedastic innovations according to a model specification first proposed by Robinson (Testing for strong serial correlation and dynamic conditional heteroscedasticity in multiple regression. J. Economet. 47 (1991), 67–84). It is shown that the averaged periodogram estimate of the spectral density of a short-memory process remains asymptotically normal with unchanged asymptotic variance under mild moment conditions, and that for strongly dependent processes Robinson's averaged periodogram estimate of long memory (Semiparametric analysis of long memory time series. Ann. Stat. 22 (1994), 515–39) remains consistent.
The process of effective critiques

Abstract Effective critiquing is a sound method for assessing, teaching and learning new technology. The processes and techniques that are critical to help students develop and evaluate their technical, aesthetic, written and verbal skills can be implemented at all levels of technical expertise and disciplines. Administering an effective critique does not begin at the completion of an assignment. It begins with the creation of the learning objectives and outcomes of a specific project. The author is drawing on industrial, art and technical educational experience to prepare projects and criteria for effective critiques. This paper will point out several different methods and approaches in preparing and conducting project critiques along with examples of how to use this approach to assess an assignment and overall course learning objectives.
An Experimental Investigation of an Airfoil Undergoing Large-Amplitude Pitching Motions

FLOW visualization and near-surface hot-wire experiments were performed in the U.S.A.F Academy Aeronautics Laboratory subsonic wind tunnel on an airfoil undergoing large-amplitude pitching motions about its quarter chord. The experiments were conducted using a NACA 0015 airfoil at an airfoil Reynolds number of 45,000. Two cases are presented in which the angular pitching rate a is maintained constant during the motion. These two cases represent two different nondimensional pitching rates a+, where ot+ is equal to 6; nondimensionalized by the chord c and the freestream velocity U^ (a + ^ac/U^). Data for the two cases where values of a+ are equal to 0.2 and 0.6 show the dramatic effect of pitch rate on flow structure. Largescale vortical structures are seen in both cases at high angles of attack but appear much later and are of a different form for the case with the larger a+ value. These structures are very energetic, producing reverse flow velocities near the airfoil surface of 1.0-2.1 times the freestream velocity.
The Strength of Thin-Walled Cylinders Subjected to Dynamic Internal Pressures

The equation of motion governing the response of long (infinite) cylinders to dynamic internal pressures is derived. Since large displacements and wall thinning effects are taken into account, elastic behavior of the material is neglected. The material is assumed to be rigid-plastic, with strain- hardening being taken into account through the Ludwik power strain hardening law. Numerical results are presented for a range of hardening constants from 0.01 to 1.0, covering the range applicable to most materials of interest. The form of the dynamic pressure considered is an initally peaked, linearly decaying pressure pulse. Charts are presented giving the pressure and duration required to produce a given final radius of the cylinder. (auth)
Mastrovito multiplier for general irreducible polynomials

We present a new formulation of the Mastrovito multiplication matrix for the field GF(2/sup m/) generated by an arbitrary irreducible polynomial. We study in detail several specific types of irreducible polynomials, e.g., trinomials, all-one-polynomials, and equally-spaced-polynomials, and obtain the time and space complexity of these designs. Particular examples illustrating the properties of the proposed architecture are also given. The complexity results established in this paper match the best complexity results known to date. The most important new result is the space complexity of the Mastrovito multiplier for an equally-spaced-polynomial, which is found as (m/sup 2/-/spl Delta/) XOR gates and m/sup 2/ AND gates, where /spl Delta/ is the spacing factor.
Newborn hospitalization: A closer look

To assess the safety of moderately early hospital discharge for normal newborn Infants (mean ±SD, 31±5 hours after delivery), we compared the incidence of hospital readmission within 6 weeks of birth with the incidence of readmission among a simllar cohort of infants with extended hospitalization (mean±SD, 92±44 hours) as a result of maternal illness. The hospital charts for all infants admitted to the well-baby nursery between January 1 and December 31, 1985, were reviewed. Fifty-two (3.0%) of the 1714 infants who were discharged moderately early and 17 (2.7%) of the 622 infants who had an extended hospitalization were readmitted to the hospital by age 6 weeks (P=NS). Matenral age, financial status, and race each failed to predict infant readmission. Only four of the 52 readmission diagnoses among infants discharged moderately early could potentially have been identified (not prevented) before discharge with an extended newborn hospitalization. These data indicate that moderately early neonatal hospital discharge does not result in an increased incidence of rehospitalization within the first 6 weeks of life.
AdS2 Quantum Gravity and String Theory

AdS2 has an SL(2,R) isometry group. It is argued that in the context of quantum gravity on AdS2 this group is enlarged to the full infinite-dimensional 1+1 conformal group. Massive scalar fields are coupled to AdS2 gravity and shown to have associated conformal weights h(m) shifted by their mass. For integral values of h primary boundary operators are obtained as h normal derivatives of the scalar field. AdS2 string theories arise in the `very-near-horizon' limit of S1-compactified AdS2 string theories. This limit corresponds to energies far below the compactification scale. The dual conformal field theory has one null dimension and can in certain cases be described as the discrete light cone quantization of a two-dimensional deformed symmetric-product conformal field theory. Evidence is given that the AdS2 Virasoro algebra is related to the right-moving AdS2 Virasoro algebra by a topological twist which shifts the central charge to zero.
Nano-optics for chemical and materials characterization

We have developed a hybrid microscope which combines structured-illumination techniques with Raman-spectroscopy to record 100 nm resolution images with chemically-specific contrast. We will show images of semiconductor nanostructures and discuss the technique?s advantages and requirements.
Dehydration, dehydrogenation, and condensation of alcohols on supported oxide catalysts based on cyclic (WO3)3 and (MoO3)3 clusters

Supported early transition metal oxides have important applications in numerous catalytic reactions. In this article, we review the synthesis and activity of well-defined model WO3 and MoO3 catalysts that are prepared via deposition of cyclic gas-phase (WO3)3 and (MoO3)3 clusters generated by sublimation of WO3 and MoO3 powders. Conversion of small aliphatic alcohols to alkenes, aldehydes/ketones, and ethers is employed to probe the structure-activity relationships on model catalysts ranging from unsupported (WO3)3 and (MoO3)3 clusters embedded in alcohol matrices, to (WO3)3 clusters supported on surfaces of other oxides, and epitaxial and nanoporous WO3 films. Detailed theoretical calculations reveal the underlying reaction mechanisms and provide insight into the origin of the differences in the WO3 and MoO3 reactivity. The catalytic activity for a range of interrogated (WO3)3 motifs (from unsupported clusters to nanoporous films) further sheds light onto the role structure and binding of (WO3)3 clusters with the support play in determining their catalytic activity.
On Second-Quantized Open Superstring Theory

Abstract The SO (32) theory, in the limit where it is an open superstring theory, is completely specified in the light-cone gauge as a second-quantized string theory in terms of a “matrix string” model. The theory is defined by the neighborhood of a 1 + 1-dimensional fixed point theory, characterized by an Abelian gauge theory with type IB Green-Schwarz form. Non-orientability and SO (32) gauge symmetry arise naturally, and the theory effectively constructs an orientifold projection of the (weakly coupled) matrix type IIB theory (also discussed herein). The fixed point theory is a conformal field theory with boundary, defining the free string theory. Interactions involving the interior of open and closed strings are governed by a twist operator in the bulk, while string endpoints are created and destroyed by a boundary twist operator.
Synthesis of SL0101 Carbasugar Analogues: Carbasugars via Pd-Catalyzed Cyclitolization and Post-Cyclitolization Transformations

A general approach to the stereoselective synthesis of 5a-carbasugars has been developed. The route mimics our palladium-catalyzed glycosylation/postglycosylation approach to carbohydrates in that it also utilizes a highly regio- and stereospecific palladium-catalyzed allylation and postglycosylation reaction sequence for the installation of either d- or l-cyclitols. This cyclitolization/postcyclitolization sequence was used for the enantioselective synthesis of a cyclitol analogue of SL0101, its d-sugar enantiomer, as well as several acetylation pattern analogues.
Mechanism of the mediated reduction of hydrogen peroxide at an electrode modified with a film containing a basic form of iridium oxide

Abstract Cyclic voltammetry of a glassy carbon electrode in an acidic PdCl 2 , Na 2 IrCl 6 mixture results in formation of a stable film on the surface. Previously it was shown to comprise palladium and iridium oxide. An iridium oxide couple in the modified electrode mediates the reduction of H 2 O 2 in the following electrolytes: neutral and basic unbuffered solutions and buffers with pH ⩾10. The current for the reduction of H 2 O 2 is limited by diffusion from the bulk solution to the film/solution interface at pH values above 12. The proposed mechanism for the mediated reduction of H 2 O 2 involves distribution of the mediator among the following three species: the oxidized and reduced state and the protonated form of the reduced state. The acidic form of the reduced state is not active in the mediation. A procedure for measuring the analogue of the pK a for a film is suggested. This value is estimated as 10.8 for iridium oxide.
Domain structures in fourth-order phase and Ginzburg-Landau equations

Abstract In pattern-forming systems, competition between patterns with different wave numbers can lead to domain structures, which consist of regions with differing wave numbers separated by domain walls. For domain structures well above threshold we employ the appropriate phase equation and obtain detailed qualitative agreement with recent experiments. Close to threshold a fourth-order Ginzburg-Landau equation is used which describes a steady bifurcation in systems with two competing critical wave numbers. The existence and stability regime of domain structures is found to be very intricate due to interactions with other modes. In contrast to the phase equation the Ginzburg-Landau equation allows a spatially oscillatory interaction of the domain walls. Thus, close to threshold domain structures need not undergo the coarsening dynamics found in the phase equation far above threshold, and can be stable even without phase conservation. We study their regime of stability as a function of their (quantized) length. Domain structures are related to zig-zags in two-dimensional systems. The latter are therefore expected to be stable only when quenched far enough beyond the zig-zag instability.
Stereoselective formation and rearrangement of morpholinium ylides derived from copper carbenoids

Abstract Amino diazoacetoacetates 4a – e and 7a , b were prepared from readily available amino alcohols and subjected to copper-catalyzed carbene-transfer reaction. Substrates 4c – e furnished the morpholin-2-ones 5c – e in good yield via the corresponding cyclic ammonium ylides, albeit with poor diastereoselectivity. Substrates 4a , b failed to provide the corresponding morpholinones, perhaps as a result of steric congestion. Cyclic substrates 7a , b underwent conversion to bicyclic morpholinones 8 and 9 in good yield and with moderate to good diastereoselectivity. This result is rationalized via control of the transiently stereogenic ammonium center of the intermediate bicyclic ylides.
Bankruptcy Costs, Liability Dollarization, and Vulnerability to Sudden Stops

Abstract Countries with intermediate levels of institutional quality suffer larger output contractions following sudden stops of capital inflows than less developed nations. However, countries with strong institutions seldom experience significant falls in output after capital flow reversals. We reconcile these two observations using a calibrated DSGE model that extends the financial accelerator framework developed in Bernanke, Gertler and Gilchrist (1999). The model captures financial market institutional quality with creditors' ability to recover assets from bankrupt firms. Bankruptcy costs affect vulnerability to sudden stops directly but also indirectly by affecting the degree of liability dollarization. Simulations reveal an inverted U-shaped relationship between bankruptcy costs and the output loss following sudden stops.
Ionization Currents in Divergent Fields in Hydrogen and in Air

Ionization currents were measured in hydrogen and in dry, mercury-free air between concentric cylinders for pressures from 0.01 mm to 760 mm. Above the pressures corresponding to the minimum sparking potentials, $(\frac{1}{r})(\frac{1}{p}) log\frac{i}{{i}_{0}}$ was a single-valued, continuous function of ${(\frac{X}{p})}_{max}$. Calculated values of apparent $\ensuremath{\alpha}$ for air agreed with uniform field values at low $\frac{X}{p}$ but were high at higher $\frac{X}{p}$. In hydrogen apparent $\ensuremath{\alpha}$ was high over the full range of variables studied. Auxiliary anodes permitted estimates of the location of the ionization which was found to agree with the spatial distribution predicted by Morton. Electrons released in the low and collected in the high field produced the same ionization as for the reverse case except at low pressure in hydrogen where about 10 percent less ionization occurred for electrons released in the low field. The peaks of Morton's $\frac{i}{{i}_{0}} \mathrm{vs}. p$ curves were identified with the minimum sparking potential. Application of the back diffusion equation of Rice permitted the evaluation of ${i}_{0}$ at higher pressures than hitherto has been possible. Comparison of the present results with those reported by Fisher and Weissler show that the present results can be directly applied if the focal length of the point parabola is substituted for $r$ in the electron multiplication parameter. On the basis of this agreement, it is expected that the present values of the parameter may be applied to any geometry in which the field varies inversely as the distance from a fixed point. A necessary condition for the application of the observed values of the parameter to any system is that the electrons give up all of their ionizing energy to the gas before being collected.
Microwave‐Hydrothermal Processing of BiFeO3 and CsAl2PO6

Microwave-hydrothermal (M-H) processing was compared with conventional-hydrothermal (C-H) processing in the crystallization of BiFeO3 and CsAl2PO6 phases. The presence of the microwave field led to accelerated kinetics of the crystallization of both these phases as detected by powder X-ray diffraction. The acceleration of reaction rates under microwave field is expected to lead to energy savings during ceramic processing.
Our Killing Schools

On Friday, December 14, 2012, a deranged 20-year-old walked into Sandy Hook Elementary in Newtown, Connecticut, and executed 20 young children and six teachers and administrators. The killer, Adam Lanza was the most recent in a long line of teenage or near-teenage boys who have committed mass murder at a public school. The statistics are frightening. Between 1997 and 2012, ten boys have killed 73 students, parents, and teachers, and wounded 99 more, in the nine most well publicized school shootings. Previously unknown places such as Pearl, Mississippi (1997); West Paducah, Kentucky (1997); Jonesboro, Arkansas (1998); Springfield, Oregon (1998); Littleton, Colorado (1999); Santee, California (2001); Red Lake, Minnesota (2005); and Chardon, Ohio (2012) have become a part of the American consciousness. The best known of these ten killers, Eric Harris and Dylan Klebold, massacred 13 students and teachers at Columbine High School and then killed themselves. The boys’ original goal (planned over a year before the attack) was to bomb and level the entire school in a series of massive explosions and then to shoot everyone left alive. They hoped to kill every single person at the school (over 2,000 students, plus 150 teachers and staff). Less well known to Americans but no less shocking is the fact that scores of boys around the United States have been arrested since 1999 for conspiracy to commit large-scale shootings and bombings at their respective schools. Here are just a few examples. In Fort Collins, Colorado, three boys were arrested in 2001 for attempting to carry-out a “Columbine-like” massacre with propane bombs and semi-automatic rifles. Their plan was to shoot as many people as possible and to then take 10 seventh-graders hostage, execute them, and then kill themselves. That same year, three teenage boys were arrested in New Bedford, Massachusetts, for conspiracy to commit mass murder at their school. After the killing spree, they planned to meet on the school roof, drink alcohol, smoke pot, drop acid, and then shoot each other in the head. Three years later, a 17year-old boy in Nebraska was arrested at his school with 20 homemade bombs and a rifle. According to officials, the boy “intended to kill everyone in the school except three friends.” On December 14, 2012— the same day as the Sandy Hook massacre—an 18-year-old boy in Bartlesville, Oklahoma, was arrested for conspiracy to launch a massive bombing and shooting attack at his high school. Despite statistics suggesting that overall school violence has declined in recent years, millions of parents send their children to school every year worried they may never come home. And with every new school shooting or attempted bombing, many Americans experience a sense of deja
A Doubly Charged Ion Model for Ion Thrusters

A theoretical equilibrium model of doubly charged ion production and loss processes in electron bombardment ion thrusters is presented. The model is shown to predict double ion density levels accurately for 15and 30-cm diam thrusters operating with several different grid sets and at several different power levels. The model indicates that the dominant mechanism of double ion production involves the singly charged ground state. This result is used to develop a much simpler model, which, along with correlations of the average plasma properties, can be used to determine the double ion density in thrusters with acceptable accuracy.
A Hierarchical Application of the Minimum Current Corona

We study the energy and helicity injected into the corona by the slow motion of photospheric source regions. A previous study compared these quantities in a simple quadrupolar configuration modeled by a quasi-static, line-tied MHD simulation and a minimum current corona (MCC). The MCC provides a lower bound for the coronal magnetic free energy by quantifying the coronal linkages (flux domains) between discrete photospheric source regions; the chosen configuration contains four flux domains and one separator. The MCC analysis can be extended by decomposing each source region into smaller ones, increasing the number of flux domains and separators. This creates a hierarchy of topological features that asymptotically approaches a line-tied model. We demonstrate the hierarchical approach using two octopolar decompositions of the previously studied quadrupole. One of these has helicity and free energy significantly closer to those of the line-tied experiment; this is primarily due to the interweaving of lower level flux domains approximating the self-helicity of a rotating region. The other decomposition does not allow such interweaving and has helicity and free energy comparable to the quadrupolar MCC configuration.
A Lyapunov optimization approach to repeated stochastic games

This paper considers a time-varying game with N players. Every time slot, players observe their own random events and then take a control action. The events and control actions affect the individual utilities earned by each player. The goal is to maximize a concave function of time average utilities subject to equilibrium constraints. Specifically, participating players are provided access to a common source of randomness from which they can optimally correlate their decisions. The equilibrium constraints incentivize participation by ensuring that players cannot earn more utility if they choose not to participate. This form of equilibrium is similar to the notions of Nash equilibrium and correlated equilibrium, but is simpler to attain. A Lyapunov method is developed that solves the problem in an online max-weight fashion by selecting actions based on a set of time-varying weights. The algorithm does not require knowledge of the event probabilities. A similar method can be used to compute a standard correlated equilibrium, albeit with increased complexity.
A New class of unstable modes of rotating relativistic stars

The first numerical study of axial (toroidal) pulsation modes of a slowly rotating relativistic star is presented. The calculation includes terms of first order in ≡ Ω(R3/M)1/2 1 (R is the radius, M is the mass, and Ω is the rotation frequency of the star) and accounts for effects due to the Coriolis force. Effects due to the centrifugal flattening of the star enter at order 2 and are not included in the analysis. It is shown that increased rotation tends to decrease the damping times for prograde modes, while retrograde modes become longer lived. Specifically, we show that rotation affects the axial gravitational wave w-modes in this way. We also present the first relativistic calculation of the so-called r-modes (analogous to Rossby waves in the Earth's oceans). These have frequencies of the same order of magnitude as the rotation frequency of the star. The presented results indicate that the r-modes are unstable due to the emission of gravitational radiation for all rotating perfect fluid stars. This is interesting, since the previously considered gravitational wave instability associated with (for example) the f-mode of the star sets in at a critical rotation rate. Because they are also unstable for the slowest rotating stars, the r-modes may well be of considerable astrophysical importance.
Assessment study of superconducting fault-current limiters operating at 77 K

The possible impact of nitrogen-cooled superconductors on the design and cost of superconducting fault current limiters is assessed by considering the technical specifications which such devices must meet, and by comparing material properties of 77 K and 4 K superconductors. The main advantage of operating superconductors at 77 K is that the refrigeration operating cost is reduced by a factor of up to 25, and the refrigeration capital cost is reduced by a factor of up to 10. The heat capacity at 77 K is several orders of magnitude larger than at 4 K. This phenomenon increases conductor stability against flux jumps but makes switching from the superconducting to normal state slow and difficult. Consequently, a high critical current density, probably at least 10/sup 5/ A/cm/sup 2/, is required. >
Oxidation of Benzoins to Benzils using Bismuth(III) Nitrate-Copper(II) Acetate

Abstract Benzoins are oxidized to benzils in excellent yields by 0.4 equivalents of Bi(NO3)3·5H2O and 4 mol% of Cu(OAc)2. Bi(NO3)3·5H2O is a stable, inexpensive, commercially available solid. The relatively low cost and low toxicity of bismuth(III) nitrate makes this procedure a particularly attractive method for oxidation of benzoins.
Numerical Simulation of Excrescence Generated Transition

Numerical computations are carried out to predict the transition generated by excrescence on a platelike geometry in subsonic flow. Both forward-facing and rearward-facing steps of small roughness height are considered in the investigation. These are representative of joints and other surface imperfections on wing sections that disrupt laminar flow, thereby increasing skin friction and drag. Solutions are obtained via a high-fidelity numerical scheme and an implicit time-marching approach on an overset mesh system that is used to represent the steps. Very-small-amplitude numerical forcing is employed to generate perturbations, which are amplified by the geometric disturbances, similar to the physical situation. The flowfield just downstream of the steps is characterized by the growth and breakdown of two-dimensional fluid structures. Because all significant scales of the flow are fully resolved in this region, the solutions there correspond to direct numerical simulations. Further downstream where the flo...
What to expect when you're expecting: femtoscopy at the LHC

A huge systematics of femtoscopic measurements have been used over the past 20 years to characterize the system created in heavy ion collisions. These measurements cover two orders of magnitude in energy, and with LHC beams imminent, this range will be extended by more than another order of magnitude. Here, I discuss theoretical expectations of femtoscopy of A+A and p+p collisions at the LHC, based on Boltzmann and hydrodynamic calculations, as well as on naive extrapolation of existing systematics.
Enantioselective Thiourea-Catalyzed Intramolecular Cope-Type Hydroamination

Catalysis of Cope-type rearrangements of bis-homoallylic hydroxylamines is demonstrated using chiral thiourea derivatives. This formal intramolecular hydroamination reaction provides access to highly enantioenriched α-substituted pyrrolidine products and represents a complementary approach to metal-catalyzed methods.
Measurement of Surface Rheological Effects on a Rotating Flow

We report measurement of azimuthal velocity as a function of radius near the boundary between a liquid annulus and (a) a rigid freely floating cylinder and (b) an air core contained in a rapidly rotating horizontal cylindrical container. Case (a) agrees with previous theoretical calculations and verifies the method. Case (b) demonstrates (1) that the interface can support stress and (2) that there is a distinct difference in the scale of radial variation in the bulk liquid from that observed in case (a).
Spiky strings and single trace operators in gauge theories

We consider single trace operators of the form l1...ln = Tr D+l1F...D+lnF which are common to all gauge theories. We argue that, when all li are equal and large, they have a dual description as strings with cusps, or spikes, one for each field F. In the case of = 4 SYM, we compute the energy as a function of angular momentum by finding the corresponding solutions in AdS5 and compare with a 1-loop calculation of the anomalous dimension. As in the case of two spikes (twist two operators), there is agreement in the functional form but not in the coupling constant dependence. After that, we analyze the system in more detail and find an effective classical mechanics describing the motion of the spikes. In the appropriate limit, it is the same (up to the coupling constant dependence) as the coherent state description of linear combinations of the operators l1...ln such that all li are equal on average. This agreement provides a map between the operators in the boundary and the position of the spikes in the bulk. We further suggest that moving the spikes in other directions should describe operators with derivatives other than D+ indicating that these ideas are quite generic and should help in unraveling the string description of the large-N limit of gauge theories.
Mining biomedical texts for disease-related pathways

I will describe my collaborators' and my own effort to compile large models of molecular pathways in complex human disorders. The talk will address a number of interrelated questions: How to extract facts from texts at a large scale? How to assess the quality of the extracted facts? How to identify sets of conflicting or unreliable facts and to generate an internally consistent model? How to use the resulting pathway model for automated generation of biological hypotheses?
Adiposity has Unique Influence on the Renin-Aldosterone Axis and Blood Pressure in Black Children

Objective To comparatively examine the effects of adiposity on the levels of plasma renin activity (PRA), plasma aldosterone concentration (PAC), and aldosterone-renin ratio (ARR) in young black and white children. Study design We prospectively assessed 248 black and 345 white children and adolescents. A novel analytical technique was used to assess the concurrent influences of age and body mass index (BMI) on PRA, PAC, and ARR. The estimated effects were depicted by colored contour plots. Results In contrast to whites, blacks had lower PRA (2.76 vs 3.36 ng/mL/h; P P P = .001), consistent with an association with a more expanded plasma volume; there was no association with PAC. In whites, BMI was positively associated with PAC ( P = .005); we did not detect a BMI-PRA association. The effects of BMI on ARR were directionally similar in the two race groups but more pronounced in blacks. Mean systolic blood pressure was greater in blacks with lower PRA ( P P = .015), and higher ARR ( P = .49). Conclusions An increase in adiposity was associated with a suppressed PRA in blacks and an increase in PAC in whites. The unique relationship between adiposity and renin-aldosterone axis in blacks suggests the possible existence of a population-specific mechanism characterized by volume expansion, which could in turn enhance the influences of adiposity on blood pressure in black children and adolescents.
State Policy Innovation and the Federalism Implications of Direct Democracy

As state policy activism has flourished in recent years, increasingly that activism has taken place through the direct democracy process. While winning ballot measures often have implications for federal-state relations, federalism issues have largely been ignored in the direct democracy literature. I address this oversight by investigating how the outcomes of direct democracy politics affect the relationships among citizens, states, and the federal government. My analysis focuses on measures proposed over the last decade that represent either a response to perceived federal inaction or a challenge to federal policy. The findings suggest that initiatives have different effects on federal-state relations depending on the form they take. When ballot measures seeking to fill a policy void lead to federal action, they promote intergovernmental policy consensus and narrow the distance between public opinion and federal policy; if the federal government fails to address the issue at stake, additional state innovation will result and voter preferences and federal policy outcomes will move farther apart. Meanwhile, initiatives that challenge federal law create conflict and polarization between states and the federal government and widen the distance between public opinion and federal policy. The passage of initiatives in both categories heightens opinion-policy congruence at the state level as officials are often eager to publicly support and implement the results of successful ballot measures.
The space of tropically collinear points is shellable

The spaceTd;n ofn tropically collinear points in a fixed tropical projective space\(\mathbb{T}\mathbb{P}^{d - 1} \) is equivalent to the tropicalization of the determinantal variety of matrices of rank at most 2, which consists of reald×n matrices of tropical or Kapranov rank at most 2, modulo projective equivalence of columns. We show that it is equal to the image of the moduli space\(\mathcal{M}_{0,n} (\mathbb{T}\mathbb{P}^{d - 1} , 1)\) ofn-marked tropical lines in\(\mathbb{T}\mathbb{P}^{d - 1} \) under the evaluation map. Thus we derive a natural simplicial fan structure forTd;n using a simplicial fan structure of\(\mathcal{M}_{0,n} (\mathbb{T}\mathbb{P}^{d - 1} , 1)\) which coincides with that of the space of phylogenetic trees ond +n taxa. The space of phylogenetic trees has been shown to be shellable by Trappmann and Ziegler. Using a similar method, we show thatTd;n is shellable with our simplicial fan structure and compute the homology of the link of the origin. The shellability ofTd;n has been conjectured by Develin in [1].
The uniform halting problem for generalized one-state turing machines*

It is shown that the uniform halting problem for one-state Turing machines is solvable. It remains solvable for various generalizations like one-state Turing machines with two-dimensional tape and jumping reading head. Other generalizations, for example, one-state Turing machines with two tapes, have an unsolvable uniform halting problem. The history of the problem is summarized.
Hydrovinylation and [2+2] Cycloaddition Reactions of Alkynes and Alkenes Catalyzed by a Well-Defined Cationic Ruthenium−Alkylidene Complex

The cationic ruthenium−alkylidene complex [(PCy3)2(CO)(Cl)RuCHCHC(CH3)2]+BF4- (1) was found to catalyze both hydrovinylation and [2+2] cycloaddition reactions of alkynes and alkenes. The reaction of R‘C⋮CR‘ ‘ (R‘ = H, Ph, n-Pr; R‘ ‘ = Ph, n-Pr, p-Tol, SiEt3, CH2CH2OH) with ethylene in the presence of 1 (3 mol %) produced the hydrovinylation products 2 and 3. The analogous reaction of dimethyl acetylenedicarboxylate (R‘ = R‘ ‘ = CO2Me) with ethylene and norbornene resulted in the formation of the [2+2] cycloaddition products 4. Based on the experimental evidence, a plausible mechanism of the hydrovinylation reaction has been proposed via a sequential insertion of alkyne and ethylene to the hydride complex 7.
Acrolein involvement in sensory and behavioral hypersensitivity following spinal cord injury in the rat.

Growing evidence suggests that oxidative stress, as associated with spinal cord injury (SCI), may play a critical role in both neuroinflammation and neuropathic pain conditions. The production of the endogenous aldehyde acrolein, following lipid peroxidation during the inflammatory response, may contribute to peripheral sensitization and hyperreflexia following SCI via the TRPA1-dependent mechanism. Here we report that there are enhanced levels of acrolein and increased neuronal sensitivity to the aldehyde for at least 14 days after SCI. Concurrent with injury-induced increases in acrolein concentration is an increased expression of TRPA1 in the lumbar (L3-L6) sensory ganglia. As proof of the potential pronociceptive role for acrolein, intrathecal injections of acrolein revealed enhanced sensitivity to both tactile and thermal stimuli for up to 10 days, supporting the compound’s pro-nociceptive functionality. Treatment of SCI animals with the acrolein scavenger hydralazine produced moderate improvement in tactile responses as well as robust changes in thermal sensitivity for up to 49 days. Taken together, these data suggests that acrolein directly modulates SCI-associated pain behavior, making it a novel therapeutic target for preclinical and clinical SCI as an analgesic.
An exploratory survey of noise levels associated with a 100‐kW wind turbine

During the past few years, NASA's Lewis Research Center has managed a wind turbine project for the Department of Energy. This effort has included the design, construction, and operation of a 125‐ft‐diam, 100‐kW wind turbine at the NASA Plum Brook Station near Sandusky, Ohio. During some of the performance tests, the opportunity arose to make exploratory noise measurements and results of those surveys are presented. The data include measurements as functions of distance from the turbine, and directivity angle, and cover a frequency range from 1 Hz to several kHz. Potential community impact is discussed in terms of A‐weighted noise levels relative to background levels, and the infrasonic spectral content. Finally, the change in the sound power spectrum associated with a change in the rotor speed is described.