cssi/SciSciGPT-SciSciNet huggingface dataset:
Direct detection and quantification of microRNAs.

The recent discovery of the potent regulatory nature of microRNAs (miRNAs), a relatively new class of approximately 22 nucleotide RNAs, has made them a primary focus in today’s biochemical and medical research. The relationship between miRNA expression patterns and the onset of cancer, as well as other diseases, has glimpsed the potential of miRNAs as disease biomarkers or drug targets, making them a primary research focus. Their promising future in medicine is hinged upon improving our scientific understanding of their intricate regulatory mechanisms. In the realm of analytical chemistry, the main challenge associated with miRNA is its detection. Their extremely small size and low cellular concentration poses many challenges for achieving reliable results. Current reviews in this area have focused on adaptations to microarray, PCR, and Northern blotting procedures to make them suitable for miRNA detection. While these are extremely powerful methods and accepted as the current standards, they are typically very laborious, semi-quantitative, and often require expensive imaging equipment and/or radioactive/toxic labels. This review aims to highlight emerging techniques in miRNA detection and quantification that exhibit superior flexibility and adaptability as well as matched or increased sensitivity in comparison to the current standards. Specifically, this review will cover colorimetric, fluorescence, bioluminescence, enzyme, and electrochemical based methods, which drastically reduce procedural complexity and overall expense of operation thereby increasing the accessibility of this field of research. The methods are presented and discussed as to their improvements over current standard methods as well as their potential complications preventing acceptance as standard procedures. These new methods have addressed the many of the problems associated with miRNA detection through the employment of enzyme-based signal amplification, enhanced hybridization conditions using PNA capture probes, highly sensitive and flexible forms of spectroscopy, and extremely responsive electrocatalytic nanosystems, among other approaches.
On the flow near a weak shock wave downstream of a nozzle throat

Abstract : In a transonic nozzle flow for which the velocity is slightly supersonic in some neighborhood of the nozzle throat, a shock wave may be present either very close to the throat or else somewhat further downstream. In the latter case, relatively simple series solutions in general provide an asymptotic description of the fluid motion except very close to the shock wave. These outer solutions are reviewed for symmetric two-dimensional flow, and a correction is derived in the form of an inner solution for a small region immediately behind the shock. The resulting solution exhibits the characteristics which are expected at the intersection of a normal shock wave and a curved wall. An extension to axisymmetric flow is also given. (Modified author abstract)
Colloidal nanoparticle clusters: functional materials by design

Significant advances in colloidal synthesis made in the past two decades have enabled the preparation of high quality nanoparticles with well-controlled sizes, shapes, and compositions. It has recently been realized that such nanoparticles can be utilized as ‘artificial atoms’ for building new materials which not only combine the size- and shape-dependent properties of individual nanoparticles but also create new collective properties by taking advantage of their electromagnetic interactions. The controlled clustering of nanoparticle building blocks into defined geometric arrangements opens a new research area in materials science and as a result much interest has been paid to the creation of secondary structures of nanoparticles, either by direct solution growth or self-assembly methods. In this tutorial review, we introduce recently developed strategies for the creation and surface modification of colloidal nanoparticle clusters, demonstrate the new collective properties resulting from their secondary structures, and highlight several of their many important technological applications ranging from photonics, separation, and detection, to multimodal imaging, energy storage and transformation, and catalysis.
Multiplication of Polynomials on Hermitian Symmetric spaces and Littlewood–Richardson Coefficients

Let be a complex reductive algebraic group and a representation of . Let denote the ring of polynomials on . Assume that the action of on is multiplicity-free. If denotes the isomorphism class of an irreducible representation of , let denote the corresponding irreducible representation and the -isotypic component of . Write for the subspace of spanned by products of and . If occurs as an irreducible constituent of , is it true that In this paper, the authors investigate this question for representations arising in the context of Hermitian symmetric pairs. It is shown that the answer is yes in some cases and, using an earlier result of Ruitenburg, that in the remaining classical cases, the answer is yes provided that a conjecture of Stanley on the multiplication of Jack polynomials is true. It is also shown how the conjecture connects multiplication in the ring to the usual Littlewood–Richardson rule.
Prediction of centrifugal pump cleaning ability in waste sludge

Radioactive waste at the Savannah River Plant (SRP) is being transferred from older waste tanks to new, stress-relieved tanks for more effective waste management. The technology developed for waste removal involves the use of long-shaft, recirculating, centrifugal pumps (slurry pumps). Testing completed at the Savannah River Laboratory's 30-meter-diameter mock-up waste tank related the effective cleaning radius (ECR) of a slurry pump to critical pump and material characteristics. Presently, this theory is being applied to radioactive waste at SRP. However, the technology can be applied to other remote handling situations where the slurry rheology can be determined. For SRP waste, an equation of the form ECR ∝ DV0 (ϱτ0)12 was determined where D is the nozzle diameter, V0 is the average initial velocity, ϱ is the density of the slurry, and τ0 is the yield stress of the slurry. Using this relationship, the cleaning performance of a pump operating in any SRP sludge environment can be predicted. Specifically, yield stress and density measurements on sludge samples can be used to predict the required number and effective location for slurry pumps in actual SRP waste tanks.
Experimental study of laser induced temporary degradation in photovoltaic PbSnTe and HgCdTe diodes

Abstract Thermal recovery processes in 8–14μm HgCdTe and PbSnTe photovoltaic detectors were investigated experimentally as a function of bias voltage, laser power and irradiation time. The detectors were exposed to CO2 laser pulses whose duration was varied from 0.2 to 200 msec. The data were recorded and processed on a Tektronix digital processing oscilloscope system. The characteristics of each photodiode were measured as a function of temperature. Significant thermal degradation was found to occur. For both detectors the thermal recovery process was observed to occur on two separate time scales, one on the order of msec and the other on the order of hundreds of msec. These results are compared to previous results for HgCdTe (PC) detectors. An analysis of the data shows that these two recovery times are related to the thermal properties of the detector and mount and its coupling to the heat sink. The relative importance of each of the thermal recovery processes is discussed for each of the bias voltages and irradiation times studies.
Cool Customers in the Stellar Graveyard I: Limits to Extrasolar Planets Around the White Dwarf G29-38

We present high-contrast images of the hydrogen white dwarf G29-38 taken in the near-infrared with the Hubble Space Telescope and the Gemini North Telescope as part of a high-contrast imaging search for substellar objects in orbit around nearby white dwarfs. We review the current limits on planetary companions for G29-38, the only nearby white dwarf with an infrared excess due to a dust disk. We add our recent observations to these limits to produce extremely tight constraints on the types of possible companions that could be present. No objects >6MJ are detected in our data at projected separations >12 AU, and no objects >16MJ are detected for separations from 3 to 12 AU, assuming a total system age of 1 Gyr. Limits for companions at separations <3 AU come from a combination of Two Micron All Sky Survey (2MASS) photometry and previous studies of G29-38's pulsations. Our imaging with Gemini cannot confirm a tentative claim for the presence of a low-mass brown dwarf. These observations demonstrate that a careful combination of several techniques can probe nearby white dwarfs for large planets and low-mass brown dwarfs.
On Gravity and the Uncertainty Principle

Heisenberg showed in the early days of quantum theory that the uncertainty principle follows as a direct consequence of the quantization of electromagnetic radiation in the form of photons. As we show here the gravitational interaction of the photon and the particle being observed modifies the uncertainty principle with an additional term. From the modified or gravitational uncertainty principle it follows that there is an absolute minimum uncertainty in the position of any particle, of order of the Planck length. A modified uncertainty relation of this form is a standard result of superstring theory, but the derivation given here is based on simpler and rather general considerations with either Newtonian gravitational theory or general relativity theory.
In vitro evaluation of the Lithoclast Ultra Vario combination lithotrite

Rigid intracorporeal lithotrites can be invaluable in the removal of large stone burdens during percutaneous nephrolithotomy. One such device, the Lithoclast Ultra Vario (LUV) has an outer ultrasound probe and inner pneumatic-ballistic probe. The ballistic probe can be advanced or retracted and run at 1–12 Hz. Since it can be difficult to predict optimal settings with any new device, we asked if in vitro testing could give insight into how best to operate this lithotrite. We tested the LUV under hands-free conditions that simulate treatment of fixed stones and freely movable stones. A fixed-stone test system measured the time to penetrate a gypsum model stone placed atop the probe and a movable-stone system determined time for comminution of a stone within a confined space. In addition, the time to evacuate 2-mm stone particles was measured. For hands-on testing, model stones were placed in a plastic dish submerged in water and the time to comminution was measured. Penetration time of fixed stones was faster with the ballistic probe extended 2.5 mm than when retracted (5.30 ± 0.85 vs. 8.75 ± 1.07 s, p < 0.0001). Comminution of free stones was faster with the ballistic probe retracted than when it was extended 1 mm or 2.5 mm (9.7 ± 0.9, 13.8 ± 1.3, 23.7 ± 3.2 s, p < 0.0001). In hands-on testing, extending the ballistic probe substantially reduced the efficiency of comminution (36.7 ± 6.4 vs. 131.3 ± 15.3 s, p < 0.0001). Clearance of fragments was considerably faster when the pneumatic-ballistic rate was 12 Hz compared to 1 Hz (12.3 ± 1.1 vs. 28.3 ± 2.2 s, p < 0.0001). These in vitro findings suggest ways to take advantage of the positive features while minimizing potential limitations of this lithotrite. Extending the ballistic probe is an advantage when the stone is immobile, as would be the case in treating a large stone that can be isolated against the wall of the pelvicalyceal system, but is a distinct disadvantage—due to retropulsion—when the stone is free to move. Operation of the LUV at fast ballistic rate significantly improved its ability to aspirate stone fragments.
SIFT: software implemented fault tolerance

Many computer applications have stringent requirements for continued correct operation of the computer in the presence of internal faults. The subject of design of such highly reliable computers has been extensively studied, and numerous techniques have been developed to achieve this high reliability. Such computers are termed "fault tolerant"; examples of applications are found in the aerospace industry, communication systems, and computer networks. Several designs of such systems have been proposed and some have been implemented. In general, these designs contain extensive hard-wired logic for such functions as fault masking, comparison, switching, and encoding-decoding.
Segregation by Racial and Demographic Group: Evidence from the San Francisco Bay Area

This paper considers residential segregation by race and by type of household in 1970 and 1980. The paper presents entropy indices of segregation for the San Francisco Bay Area and its five metropolitan areas. The methodology permits an investigation of the effects of group definition upon segregation measures, and an analysis of the degree of independence in the segregation of households by race and demographic group. The results indicate that the levels of segregation by race and by household type have declined modestly during the 1970s, at least in this region. More importantly, however, the results indicate a remarkable independence in the spatial distribution of households by race and demographic group. Only a very small fraction of the observed levels of segregation by race could be ’explained’ by the prior partitioning of households by demographic group. The principal results of the analysis are invariant to changes in the definition of racial or household groups.
Photosensitized defluorination of saturated perfluorocarbons

Abstract UV irradiation of perfluorodecalin 1 in the presence of an electron donor results in the facile formation of perfluoroolefin 2 from the selective elimination of the vicinal tertiary fluorines.
Tension-Dependent Dynamic Microtubule Model for Metaphase and Anaphase Phenomena

We present a theoretical model describing metaphase chromosome oscillations, microtubule (MT) attachment error correction, and anaphase chromosome separation. During metaphase, chromosome pairs align near the center of a bipolar MT spindle and oscillate as the MTs attaching them to the cell poles polymerize and depolymerize. Simultaneously, the cell fixes misaligned chromosome pairs by some tension-dependent mechanism. In anaphase, chromosome pairs separate as depolymerizing MTs pull each chromosome toward its respective cell pole. Instead of including all known components to develop a comprehensive, species-specific description, we introduce a minimal model based on fundamental properties of MT kinetics. We use the tension-dependence of single MT polymerization/depolymerization kinetics measured by Akiyoshi et al. [1] and assume the same functional dependence for compressed MTs. We apply these to a many MT model, and solve this stochastic model numerically and by a master equation approach. We find that the tension dependence of rates enhances the speed of single chromosome pulling by MTs during anaphase- or error-correction-like behavior. Additionally, the force-velocity curve for a single chromosome attached to dynamic MTs exhibits bi-stability: at high loads, large tension fluctuations induce MTs to spontaneously switch from a depolymerizing state into a polymerizing state. The system is hysteretic; to recover depolymerization from the polymerizing state, the load must be decreased to a far smaller value than that required to initially induce polymerization. This behavior leads to the chromosome oscillations we observe in the two-chromosome system. Interestingly, we observe breathing oscillations, which are not captured by any other chromosome oscillation model. Our minimal model reflects general features of the underlying mechanisms of these phenomena, and reveals how different components control chromosome dynamics through the rate constants.[1] Akiyoshi et al. (2010) Nature 468, 576-579.
The Democratic Domino Theory: An Empirical Investigation

According to the democratic domino theory, increases or decreases in democracy in one country spread and “infect” neighboring countries, increasing or decreasing their democracy in turn. Using spatial econometrics and panel data that cover over 130 countries between 1850 and 2000, this article empirically investigates the democratic domino theory. We find that democratic dominoes do in fact fall as the theory contends. However, these dominoes fall significantly “lighter” than the importance of this model suggests. Countries “catch” only about 11% of the increases or decreases in their average geographic neighbors’ increases or decreases in democracy. This finding has potentially important foreign policy implications. The “lightness” with which democratic dominoes fall suggests that even if foreign military intervention aimed at promoting democracy in undemocratic countries succeeds in democratizing these nations, intervention is likely to have only a small effect on democracy in their broader regions.
Auto-Gopher: a wire-line rotary-hammer ultrasonic drill

Developing technologies that would enable NASA to sample rock, soil, and ice by coring, drilling or abrading at a significant depth is of great importance for a large number of in-situ exploration missions as well as for earth applications. Proven techniques to sample Mars subsurface will be critical for future NASA astrobiology missions that will search for records of past and present life on the planet, as well as the search of water and other resources. A deep corer, called Auto-Gopher, is currently being developed as a joint effort of the JPL's NDEAA laboratory and Honeybee Robotics Corp. The Auto-Gopher is a wire-line rotary- hammer drill that combines rock breaking by hammering using an ultrasonic actuator and cuttings removal by rotating a fluted bit. The hammering mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) that has been developed as an adaptable tool for many of drilling and coring applications. The USDC uses an intermediate free-flying mass to transform the high frequency vibrations of the horn tip into a sonic hammering of a drill bit. The USDC concept was used in a previous task to develop an Ultrasonic/Sonic Ice Gopher. The lessons learned from testing the ice gopher were implemented into the design of the Auto-Gopher by inducing a rotary motion onto the fluted coring bit. A wire-line version of such a system would allow penetration of significant depth without a large increase in mass. A laboratory version of the corer was developed in the NDEAA lab to determine the design and drive parameters of the integrated system. The design configuration lab version of the design and fabrication and preliminary testing results are presented in this paper.
Preliminary Evaluation of a Modified Mueller-Hortig Geometry Negative Ion Source Using a Negative Ion Source Test Facility

A negative sputter-type ion source of the Mueller-Hortig geometry is described which utilizes a positive surface ionization source. Among the ion beams which have been produced are: A1-0.2 ?A; A10--3 ?A; Au--6 ?A; C--25 ?A; C2--20 ?A; Cl--100 ?A; Cu--0.5 ?A; CuO--0.8 ?A; F--40 ?A; I--26 ?A; 0--30 ?A; Pt--3 ?A; S--44 ?A; TaO2--2 ?A. The yields of Cl-, F-, O-, and S- produced from gaseous or high vapor pressure compounds are observed to be sensitively dependent on the metallic surface from which they are generated - indicating an intermediate surface chemical effect. While the source produces very intense beams of the halogens, sulfur, and oxygen and relatively intense beams of the metallic oxides, there appears to be a need for additional surface cesium to ensure maximum negative ion yields from many of the elemental materials.
Policy Reform and Growth in Post-Soviet Russia

In pursuit of its transition from a command to a market economy, Russia has witnessed enormous regional differences in economic growth rates. Moreover, the implementation of economic reforms has also differed markedly across regions. We analyze whether regional differences in reform policies can account for regional differences in growth rates, and conclude that to a considerable degree, they can. Most notably, we find that regional differences in price liberalization policies exhibit a positive direct correspondence with growth. We also find that regional differences in large-scale privatization exhibit a positive correspondence with the regional formation of new legal enterprises, which in turn exhibits a strong positive correspondence with growth.
Supersymmetric statistical models on the lattice

Abstract SUSY models in statistical mechanics involve spinless fermions and form an ideal laboratory for latticization. Extension of SUSY relations to the lattice may clarify, as well, the question of their validity beyond perturbation theory. A non-linear approach to lattice SUSY is introduced by the assignment of coupled commuting variables to each lattice site. As a typical example we demonstrate a SUSY dimer Hamiltonian which generates lattice branched-polymer configurations. We suggest a new SUSY model whose configurations are generated by the Ising super-Hamiltonian. These configurations cannot be simply related to the high temperature expansion of the random-field Ising model. The critical behavior of the random-field model is probably in the non-perturbative regime with thermal fluctuations squeezed into d-dimensional manifolds in the boundaries of frozen domains. Self-consistent reduction yields d = (d + 1/v)/2 if α d = d − 1/v if α > 0, where d is the actual spatial dimension and α and v are the critical exponents of the specific heat and correlation length, respectively. This may be explained in terms of anomalous “anticommuting dimensions.”
Pigou at the Plate: Externalities in Major League Baseball

Past studies estimating the marginal revenue products of baseball players have assumed individual players' hitting performances to be independent of teammate spillovers. However, the baseball commu...
High precision predictions for near-Earth asteroids: the strange case of (3908) Nyx

In November 2004 radar delay measurements of near-Earth asteroid (3908) Nyx obtained at the Arecibo radio telescope turned out to be $$7.5\sigma $$ away from the orbital prediction. We prove that this discrepancy was caused by a poor astrometric treatment and an incomplete dynamical model, which did not account for nongravitational perturbations. To improve the astrometric treatment, we remove known star catalog biases, apply suitable weights to the observations, and use an aggressive outlier rejection scheme. The main issue related to the dynamical model is having not accounted for the Yarkovsky effect. Including the Yarkovsky perturbation in the model makes the orbital prediction and the radar measurements statistically consistent by both reducing the offset and increasing the prediction uncertainty to a more realistic level. This analysis shows the sensitivity of high precision predictions to the astrometric treatment and the Yarkovsky effect. By using the full observational dataset we obtain a $$5\sigma $$ detection of the Yarkovsky effect acting on Nyx corresponding to an orbital drift $$da/dt = (142 \pm 29)$$ m/year. In turn, we derive constraints on thermal inertia and bulk density. In particular, we find that the bulk density of Nyx is around 1 g/cm $$^3$$ , possibly less. To make sure that our results are not corrupted by an asteroid impact or a close approach with a perturbing asteroid not included in our dynamical model, we show that the astrometry provides no convincing evidence of an impulsive variation of Nyx’s velocity while crossing the main belt region.
The effect of chloride ions on the gamma-radiation-induced destruction of DNA, nucleosides and nucleotides in aqueous solution.

SummaryDNA in oxygenated aqueous solution is protected from the effects of ionizing radiation by chloride ions, as measured by chromophore destruction. The mechanism of this protection is probably a change in the mode of decay of the DNA-OH radicals and not a change in the primary attacking species. Chloride ions have no effect on the radiation-induced destruction of nucleosides and nucleotides in neutral solution. The chloride effects observed for these compounds in acid solution can be attributed to conversion of OH radicals to Cl2− ion radicals, and differences in the reaction of the latter species with solutes. There is no observable chloride effect on thymine or adenine compounds. The reaction of Cl2− with pyrimidine nucleosides and nucleotides results in destruction of the glycosidic bond and the release of undamaged base. This effect is not observed with the purine compounds or with the deoxyribose compounds. The radical which results from the reaction of Cl2− with guanine compounds reacts efficien...
The Gregory-Laflamme instability for the D2-D0 bound state

The D2-D0 bound state exhibits a Gregory-Laflamme instability when it is sufficiently non-extremal. If there are no D0-branes, the requisite non-extremality is finite. When most of the extremal mass comes from D0-branes, the requisite non-extremality is very small. The location of the threshold for the instability is determined using a local thermodynamic analysis which is then checked against a numerical analysis of the linearized equations of motion. The thermodynamic analysis reveals an instability of non-commutative field theory at finite temperature, which may occur only at very long wavelengths as the decoupling limit is approached.
Strain Measurements of Silicon Dioxide Microspecimens by Digital Imaging Processing

Silicon dioxide thin film is a common component in electronic devices and in MEMS, but its mechanical properties have rarely been studied. Techniques have been adapted and developed to conduct tensile tests on 1.0 μm thick silicon dioxide specimens that are 100, 150, and 200 μm wide and either 1 or 2 mm long. One end of the specimen remains fastened to the substrate, and the other is glued to a silicon carbide fiber attached to a 30 g load cell mounted on a piezoelectric translation stage. Strain is measured by digital imaging of two gold lines applied to the gage section of the transparent specimen. Twenty-five tests yield a Young’s modulus of 60.1 ± 3.4 GPa and a fracture strength of 364 ± 57 MPa.
Radial Alignment in Simulated Clusters

Observational evidence for the radial alignment of satellites with their dark matter host has been accumulating steadily over the past few years. The effect is seen over a wide range of scales, from massive clusters of galaxies down to galaxy-sized systems, yet the underlying physical mechanism has still not been established. To this end, we have carried out a detailed analysis of the shapes and orientations of dark matter substructures in high-resolution N-body cosmological simulations. We find a strong tendency for radial alignment of the substructure with its host halo: the distribution of halo major axes is very anisotropic, with the majority pointing toward the center of mass of the host. The alignment peaks once the subhalo has passed the virial radius of the host for the first time, but is not subsequently diluted, even after the halos have gone through as many as four pericentric passages. This evidence points to the existence of a very rapid dynamical mechanism acting on these systems, and we argue that tidal torquing throughout their orbits is the most likely candidate.
A facile method for deprotection of trityl ethers using column chromatography

Abstract A mild, efficient and inexpensive detritylation method is reported that uses trifluoroacetic acid on a silica gel column to obtain pure, detritylated compounds in one-step. This method is applicable to acid stable as well as acid sensitive compounds with only slight alterations in the procedure. Nineteen examples are given.
Is venture capital worth it? Effects on firm performance and founder returns

Abstract This paper extends research on venture capital (VC) finance by studying its effects on a venture's performance and on its founders' returns beyond an initial public offering (IPO). A “founder performance” construct, defined as a founder's financial and nonfinancial returns, is proposed and used to measure and compare returns to founders with returns to investors and firm performance. In general, venture characteristics pre-IPO and venture performance post-IPO were not significantly different when comparing ventures with and without VC backing. Only when VC backing is very high, do pre-IPO resources and funding improve significantly. However, higher levels of resource endowments did not seem to affect post-IPO performance for the venture or its investors. On the other hand, founders resorting to VC funding before taking their company public generated significantly less wealth for themselves and were less likely to remain as CEOs of their ventures after the IPO. Results suggest that founders motivated primarily by wealth creation and those motivated by remaining in control of their ventures should, in both instances, minimize VC backing when taking their ventures public. The finding that founder performance differs from venture and investor performance calls for future research to explore potential conflicts of interest that may arise from the double role of founders as principals and agents.
Experience with the Baerveldt Glaucoma Implant in Treating Neovascular Glaucoma

Purpose: The authors present a retrospective study designed to assess the effectiveness of the Baerveldt glaucoma implant in controlling intraocular pressure (10P) and maintaining visual function in eyes with neovascular glaucoma. Methods: The medical records of all 36 patients (36 eyes) who underwent Baerveldt glaucoma implantation for medically uncontrolled neovascular glaucoma between February 1991 and December 1992 were reviewed. Results: Eighteen patients received Model 350 implants, 16 received Model 500 implants, and 2 received Model 200 implants. The 12- and 18-month life-table success rates (success defined as 6 mmHg ≤ final IOP ≤ 21 mmHg without additional "glaucoma surgery or devastating complication) were 79% and 56%, respectively. Visual acuity remained stable or improved in 10 (31 %) patients. Postoperative complications included flat anterior chamber, serous choroidal detachment, and obstruction of the proximal tube tip with fibrovascular tissue, each of which occurred in four (11 %) patients. Eleven (31 %) patients lost light perception. There were no significant differences between the groups receiving the Model 350 and Model 500 implants with respect to life-table success rates, percentage of postoperative IOP reduction, or complication rates. Patients in the Model 500 implant group required significantly fewer antiglaucoma medications postoperatively, but also demonstrated a significantly greater mean visual acuity reduction. Better preoperative visual acuity and increased patient age were positively correlated with a successful outcome. Conclusions: Baerveldt implantation is effective in controlling IOP elevation associated with neovascular glaucoma. Postoperative visual loss, despite adequate IOP control, is common. Young patient age and poorer preoperative visual acuity are significant predictors of surgical failure.
Theory of competition between synchronous and nonsynchronous modes in a magnicon output cavity

In the magnicon amplifier, a scanning electron beam drives a synchronous fast‐wave interaction in a cylindrical output cavity. The output cavity is designed to support a synchronous transverse magnetic (TM) waveguide mode, usually the TM210 mode. However, a number of other transverse electric (TE) or TM modes can be excited in the cavity via a nonsynchronous, gyrotron‐type interaction. To investigate the possibility of competition from these nonsynchronous modes, a multimode gyrotron simulation theory and code have been adapted to the magnicon configuration. The gyrotron theory and corresponding code have been generalized to include a synchronous TM mode as well as nonsynchronous TE modes. Proper phase averaging between the modes, and between the modes and the beam electrons, is critical to accurate mode competition calculations. In nonsynchronous interactions this is achieved by averaging with respect to electron entrance time and the orbit guiding center angle. The synchronous mode interaction is invari...
Prussian blue: a new framework of electrode materials for sodium batteries

Prussian blue and its analogues consisting of different transition-metal ions (Fe, Mn, Ni, Cu, Co and Zn) have been synthesized at room temperature. Insertion of Na into KFe2(CN)6 in a carbonate electrolyte exhibited a reversible capacity near 100 mA h g−1 with no capacity fade in 30 cycles. The data indicate that a Na-ion battery with a Prussian blue framework as a cathode will be feasible.
VENUS: AN UPPER LIMIT ON INTRINSIC MAGNETIC DIPOLE MOMENT BASED ON ABSENCE OF A RADIATION BELT.

On the basis of the absence of energetic electrons (E(e) 45 kiloelectron volts) and protons (E(p) 320 kiloelectron volts) associated with Venus to within a radial distance of 10,150 kilometers from the center of the planet and using a physical similitude argument and the observational and theoretical knowledge of the magnetosphere of Earth, we conclude that the intrinsic magnetic dipole moment of Venus is almost certainly less than 0.01 and probably less than 0.001 of that of Earth. Corresponding upper limits on the magnetic field at the equatorial surface of Venus are about 350 and 35 x 10(-5) gauss, respectively.
Active Vibration Control of Rotating Machinery Using Piezoelectric Actuators Incorporating Flexible Casing Effects

The modern trend toward lighter and more flexible designs in rotating machinery brings with it increasing demands for ways to dissipate the excess energy transferred to such structures by the action of dynamic forces. The present study incorporates the use of active feedback control mechanisms to suppress this unwanted vibration. The basic active damping scheme involves the introduction of a control force on the structure from a feedback network whose input is dictated by the motion of the structure. The control force is applied to the rotor bearing support housing via a piezoelectric actuator attached to the rotor casing. The current research extends previous electromechanical simulations by incorporating a flexible finite element shell model of the casing to support the actuator and sensors. Actuator and feedback loop dynamics are included in the stability and response simulation
Reversals of the Earth's magnetic field and the acceptance of crustal mobility in North America: A view from the trenches

In this paper I shall attempt to give a personal view of the acceptance of ideas of crustal mobility by a key group of scientists at Lamont-Doherty Geological Observatory, Palisades, N.Y., which in turn, largely because of the data marshalled by these researchers, led to the acceptance of the concept of mobility by the larger scientific community in the United States. This took place in 1964–1966 and led to are markable and rapid transformation in the way that earth scientists view our planet. In large part the change followed the acceptance of reversals of the earth's magnetic field by earth scientists in general.
PHYSICS RESULTS FROM RICH DETECTORS

Abstract RICH detectors have become extraordinarily useful. Results include measurement of solar neutrino rates, evidence for neutrino oscillations, measurement of TeV γ -rays from gravitational sources, properties of QCD, charm production and decay, and measurement of the CKM matrix elements V cs , V cb and V ub . A new value |V ub /V cb |=0.087±0.012 is determined.
Modeling and experimental assessment of CN radiation behind a strong shock wave

Assessment of nonequilibrium thermochemical models for shock-layer radiation in N 2 /CH 4 mixtures is presented via comparisons with spectrally and temporally resolved intensity measurements from a set of shock tube experiments. The experiments were carried out at the Electric Arc Shock Tube facility at NASA Ames Research Center in a rarified environment [13.3-133.3 Pa (0.1 and 1 torr)] representative of the peak heating conditions of a Titan aerocapture trajectory (5-9 km/s). The baseline model that assumes a Boltzmann population of the CN excited states consistently overpredicts the shock-layer radiation intensity at lower pressure [13.3 Pa (0.1 torr)]. A nonlocal collisional radiative model that solves a simplified master equation and includes radiative transport and nonlocal absorption in the shock tube is presented. The proposed model improves the prediction of the nonequilibrium radiation overshoot peak, but still underpredicts the intensity decay rate in the low-pressure case. Further analysis suggests possible reasons for the remaining disagreement, the most likely being a slow CN consumption in the current chemical kinetics model in the intensity fall-off region.
On the Plutinos and Twotinos of the Kuiper Belt

We illuminate dynamical properties of Kuiper belt objects (KBOs) in the 3 : 2 (Plutino) and 2 : 1 ("Twotino") Neptunian resonances within the model of resonant capture and migration. We analyze a series of numerical integrations, each involving the four migratory giant planets and 400 test particles distributed throughout trans-Neptunian space, to measure the efficiencies of capture into the 3 : 2 and 2 : 1 resonances, the efficiencies of capture into Kozai-type secular resonances, and the libration centers and amplitudes of resonant particles, all as functions of the migration speed. We synthesize instantaneous snapshots of the spatial distribution of ~104 resonant KBOs, from which we derive the longitudinal variation of the sky density of each resonant family. Twotinos cluster ±75° away from Neptune's longitude, while Plutinos cluster ±90° away. Such longitudinal clustering persists even for surveys that are not volume limited in their ability to detect resonant KBOs. Remarkably, between -90° and -60° of Neptune's longitude we find the ratio of sky densities of Twotinos to Plutinos to be nearly unity, despite the greater average distance of Twotinos, assuming the two resonant populations are equal in number and share the same size, albedo, and inclination distributions. We couple our findings to observations to crudely estimate that the intrinsic Twotino population is within a factor of ~3 of the Plutino population. Most strikingly, the migration model predicts a possible asymmetry in the spatial distribution of Twotinos: more Twotinos may lie at longitudes behind that of Neptune than ahead of it. The magnitude of the asymmetry amplifies dramatically with faster rates of migration and can be as large as ~300%. A differential measurement of the sky density of 2 : 1 resonant objects behind and in front of Neptune's longitude would powerfully constrain the migration history of that planet.
Beautiful CP violation

Abstract CP violation is observed to date only in K0 decays and is parameterizable by a single quantity e. Because it is one of the least understood phenomena in the Standard Model and holds a clue to baryogenesis, it must be investigated further. Highly specialized searches in K0 decays are possible. Effects in B decays are much larger. In addition to the traditional B d → J/ψK S , π + π − asymmetries, CP violation could be searched for in already existing inclusive B data samples. The rapid B s − B s oscillations cancel in untagged Bs data samples, which therefore allow feasibility studies for the observation of CP violation and the extraction of CKM elements with present vertex detectors. The favored method for the extraction of the CKM angle γ is shown to be unfeasible and a solution is presented involving striking direct CP violation in charged B decays. Novel methods for determining the Bs mixing parameter Δm are described without the traditional requirement of flavor-specific final states. The CKM phase φ=−2β−γ=−π+α−β can be obtained from time-dependent studies of B d (t)→ D (∗)± π ∓ , even in the presence of possible final-state interactions.
Measurement of electron-muon correlations from semi-leptonic D decay in 200 GeV p + p collisions at RHIC-PHENIX

Charm production is a valuable probe of the early stages of a heavy ion collision. Correlated electron-muon pairs are a signature of semi-leptonic D decays, and a measurement of D mesons provides information on charm quark energy loss in the hot medium. The energy loss of heavy quarks is still not fully understood, so it is vital to investigate different decay channels of charm mesons to better understand this process. Measurements of electron-muon pairs suffer less from background than e+e− or µ+µ− pairs since neither direct lepton production nor resonance decays produce this type of correlated signal. Another advantage is that because electrons are measured in the central arms and muons are measured in the forward region in PHENIX, open charm can be probed in a rapidity region different from previous dilepton measurements. Studying electron-muon pairs in p + p collisions provides an important baseline for the study of these processes in d + Au and Au + Au collisions. The data in this analysis was obtained during the 2006 RHIC run of p + p collisions at 200 GeV. The current status of this analysis will be presented.
In-plane response of laminates with spatially varying fiber orientations - Variable stiffness concept

A solution to the plane elasticity problem for a symmetrically laminated composite panel with spatially varying fiber orientations has been obtained. The fiber angles vary along the length of the composite laminate, resulting in stiffness properties that change as a function of location. This work presents an analysis of the stiffness variation and its effects on the elastic response of the panel. The in-plane response of a variable stiff ness panel is governed by a system of coupled elliptic partial differential equations/Solving these equations yields the displacement fields, from which the strains, stresses, and stress resultants can be subsequently calculated. A numerical solution has been obtained using an iterative collocation technique. Corresponding closed-form solutions are presented for three sets of boundary conditions, two of which have exact solutions, and therefore serve to validate the numerical model. The effects of the variable fiber orientation on the displacement fields, stress resultants, and global stiffness are analyzed.
Operative Report Teaching and Synoptic Operative Reports: A National Survey of Surgical Program Directors

Background Although operative report documentation (ORD) is an essential skill for surgeons and is evolving with electronic health records (EHRs), little is known about current ORD teaching in surgical training. Study Design An electronic survey was sent out in January 2012 to all 1,096 ACGME surgical program directors that assessed characteristics of training programs, EHR adoption, ORD education, synoptic or templated report usage for ORD, and attitudes and opinions about ORD education and electronic tools for ORD. Content thematic analysis of qualitative responses was performed iteratively until reaching saturation. Results Overall, 441 program directors (40%; 17.9 ± 8.8 years in practice) responded from university-affiliated (383 [87%]), community/private (44 [10%]), and military (14 [3%]) programs. Although most (n = 295 [67%]) consider ORD teaching a priority, only 76 (17%) programs provide ORD instruction. Program directors formally trained in ORD were more likely to offer ORD instruction (61% vs 11%; p Conclusions Although most program directors consider ORD teaching an educational priority, incongruence exists between its perceived value and its adoption into surgical training. Operative report documentation with synoptic reporting is currently not common in most surgical subspecialties.
Enantioselective, cyclopentene-forming annulations via NHC-catalyzed benzoin-oxy-cope reactions.

Chiral N-heterocyclic carbene catalysts generated from triazolium salts promote the cyclopentene-forming annulation of α,β-unsaturated aldehydes and 4-oxoenoates with excellent levels of enantioinduction and preference for the cis-1,3,4-trisubstituted cyclopentene diastereomer. Although the observed products could arise by conjugate additions of catalytically generated homoenolates, our mechanistic and stereochemical investigations strongly support a novel reaction manifold featuring an intermolecular crossed-benzoin reaction and an NHC-catalyzed oxy-Cope rearrangement.
Orientifold and F-theory duals of CHL strings

Abstract We present orientifold and F-theory duals of the heterotic string compactification constructed by Chaudhuri, Hockney and Lykken (CHL) which has the maximal supersymmetry but gauge group of reduced rank. The 8-dimensional dual is given by the Type IIA orientifold on the Mobius band. We show the non-trivial monodromy on the base induces non-simply laced gauge groups on the F-theory orbifolds dual to the CHL strings. The F-theory models dual to the CHL strings in six dimensions are examples of N =2 F-theory vacua. We discuss the other N =2 F-theory vacua in six dimensions.
The effect of T cells from patients with infectious mononucleosis on CFU-CGM proliferation: a preliminary report.

The neutropenia occurring during infection is a poorly understood phenomenon. Immunologically-stimulated T lymphocytes, acting upon normal bone marrow stem cells, have been etiologically implicated in several disorders. Fifteen patients, ages 17 to 25 years, and diagnosed with infectious mononucleosis by positive heterophile titers, were studied. Peripheral blood T lymphocytes were separated using sheep red blood cell rosetting. They were then cocultured with normal bone marrow cells, in a concentration of 2 × 104 cells/ml, in methylcellulose containing 10% colony-stimulating activity. Normal BM was obtained from patients with nonmalignant hematologic disorders, or leukemia in remission. Bone marrow cells were cultured at a concentration of 1 × 105 or 5 × 105 cells/ml, alone (control) or with T lymphocytes. Plates were incubated at 37°C with 5% CO2. Colonies were scored at 14 days. Inhibition of normal, bone marrow growth was observed at both concentrations, after addition of T lymphocytes to the culture system. Such suppression was significant (p < 0.05) for the lower concentration of normal bone marrow cells only. Variable and partial abrogation of effect was seen after overnight incubation of T lymphocytes, possibly due to loss of suppressor activity. There were insufficient numbers of tests with supernatant to allow computation of statistical significance. Correlation between T-cell ratios and suppressive effect has not been determined, although it is suspected that the responsible cells are within the T-suppressor fraction.
Measurement of the electron affinity of lanthanum

The electron affinity of lanthanum has been measured using laser photoelectron energy spectroscopy. This is the first electron affinity measurement for lanthanum and one of the first measurements of an electron affinity of a rare-earth series element. The electron affinity of lanthanum was measured to be . At least one bound excited state of was also observed in the photoelectron spectra, and the binding energy relative to the ground state of lanthanum was measured as . The present experimental measurements are compared to a recent calculation.