cssi/SciSciGPT-SciSciNet huggingface dataset:
Recent Advances in Estimating Term-Structure Models

In the past 10 years, increasingly sophisticated statistical techniques have been applied to the estimation of increasingly complex models of the term structure of interest rates. In reviewing this literature, we highlight the facts that have been established and the key unresolved issues. The data indicate that within a wide range of interest rates, mean reversion in rates is, at best, weak. Whether mean reversion is stronger for very high or very low levels of rates is an unresolved issue. The absolute volatility of rates increases as the level of rates increases, but the strength of this effect and the role and nature of either stochastic-volatility or regime-switching components in rates are still unclear. Unfortunately, these unresolved issues have important implications for fixed-income option pricing and risk measurement, including value-at-risk calculations.
Renormalizing curvature integrals on Poincaré–Einstein manifolds

Abstract After analyzing renormalization schemes on a Poincare–Einstein manifold, we study the renormalized integrals of scalar Riemannian invariants. The behavior of the renormalized volume is well known and we show any scalar Riemannian invariant renormalizes similarly. We consider characteristic forms and their behavior under a variation of the Poincare–Einstein structure and obtain, from the renormalized integral of the Pfaffian, an extension of the Gauss–Bonnet theorem.
Hydrogeologic inferences from drillers' logs and from gravity and resistivity surveys in the Amargosa Desert, southern Nevada

Abstract The Amargosa Desert of southern Nevada, in the Basin and Range province, is hydraulically downgradient from Yucca Mountain, the potential site of a repository for high-level nuclear waste. Groundwater flow paths and flow rates beneath the Amargosa Desert are controlled in part by the total saturated thickness and the hydraulic properties of basin-fill alluvial sediments. Drillers' logs of water wells completed in alluvium were analyzed to help characterize the hydrogeologic framework underlying the Amargosa Desert. Fractions of coarse-grained sediments, calculated from each of these logs, were contoured using a universal-kriging routine to interpolate values. Results from a previous electrical sounding survey also were contoured, including the estimated depth to Paleozoic (?) basement rocks. The vertical electric sounding results were obtained from individual depth-to-resistivity profiles, from which the average resistivity of the total profile and the resistivity of the upper 75 m were calculated. The distribution and variations in average resistivity of the total depth correlated reasonably well with the distribution of variations in regional gravity. Patterns of contours of the resistivity of the upper 75 m of alluvium were similar to patterns of regional contours of the predominant cation (sodium) in ground water. Gravity lows correspond in some places to the presence of lacustrine, eolian, or marsh surface deposits, which may function as barriers to groundwater flow. Gravity lows also correspond to areas with thick basin-fill sediments, which was corroborated by depth-to-basement data determined from vertical electric soundings. Depths to Paleozoic (?) basement rocks may be as much as 1600 m based on data from the resistivity survey, which were corroborated in part by seismic-refraction survey data. Small variations exist in the percentage of the basin fill that is saturated. The unsaturated zone is always
Infeasibility of instance compression and succinct PCPs for NP

The OR-SAT problem asks, given Boolean formulae @f"1,...,@f"m each of size at most n, whether at least one of the @f"i's is satisfiable. We show that there is no reduction from OR-SAT to any set A where the length of the output is bounded by a polynomial in n, unless NP@?coNP/poly, and the Polynomial-Time Hierarchy collapses. This result settles an open problem proposed by Bodlaender et al. (2008) [6] and Harnik and Naor (2006) [20] and has a number of implications. (i) A number of parametric NP problems, including Satisfiability, Clique, Dominating Set and Integer Programming, are not instance compressible or polynomially kernelizable unless NP@?coNP/poly. (ii) Satisfiability does not have PCPs of size polynomial in the number of variables unless NP@?coNP/poly. (iii) An approach of Harnik and Naor to constructing collision-resistant hash functions from one-way functions is unlikely to be viable in its present form. (iv) (Buhrman-Hitchcock) There are no subexponential-size hard sets for NP unless NP is in co-NP/poly. We also study probabilistic variants of compression, and show various results about and connections between these variants. To this end, we introduce a new strong derandomization hypothesis, the Oracle Derandomization Hypothesis, and discuss how it relates to traditional derandomization assumptions.
Pulsed Plasma and Low-Pressure Detonator Thrusters for Secondary Propulsion of Spacecraft

References 1 Perel, J. et al., "Research and Development of a Charge Particle Bipolar Thruster," AIAA Journal, Vol. 7, No. 3, March 1969, pp. 507-511. 2 Huberman, M. N. et al., "Present Status of Colloid Microthruster Technology," Journal of Spacecraft and Rockets, Vol. 5, No. 11, Nov. 1968, pp. 1319-1324. 3 Burson, W. C., "Research on Electrohydrodynamic Charged Droplet Beams," AFAPL-TR-67-199, Oct. 1967, Air Force Systems Command, Wright-Patterson Air Force Base, Ohio. 4 Stark, K. W. and Sherman, A., "Research and Development in Needle and Slit Colloid Thrusters," TND-5305, Feb. 1970, NASA. 5 Hendricks, C. D., "Research on High Intensity Charged Particle Sources," AFAPL-TR-67-92, Aug. 1967, Air Force Aero Propulsion Lab., Wright-Patterson Air Force Base, Ohio. 6 Pfeifer, R. J. and Hendricks, C. D., "Charge to Mass Relationships for Electrohydrodynamically Sprayed Liquid Droplets," The Physics of Fluids, Vol. 10, No. 10, Oct. 1967, pp. 21492154. 7 Sherman, A., "Parametric Analysis of Electrostatic Dispersion of a Liquid," X-734-67-321, July 1967, NASA. 8 Kidd, P. W., "Parametric Studies with a Single Needle Colloid Thruster," Journal of Spacecraft and Rockets, Vol. 5, No. 9, Sept. 1968, pp. 1034-1039. 9 Perel, J., Yahiku, A. Y., and Mahoney, J. F., "Focusing and Deflection of Heavy Charged Particle Beams," AIAA Paper 69-283, March 1969, Williamsburg, Va. 10 Perel, J., Mahoney, J. F., and Yahiku, A. Y., "Analytical Study of Colloid Annular Thrusters," AIAA Paper 70-1113, Aug.Sept. 1970, Stanford, Calif.
Disclination unbinding transition in quantum Hall liquid crystals

We derive the long-wavelength elastic theory for the quantum Hall smectic state starting from the Hartree-Fock approximation. Dislocations in this state lead to an effective nematic model for $Tg0,$ which undergoes a disclination unbinding transition from a phase with algebraic orientational order into an isotropic phase. We obtain transition temperatures that are in qualitative agreement with recent experiments that have observed large anisotropies of the longitudinal resistivities in half-filled Landau levels, lending credence to the liquid crystal interpretation of experiments.
Raising the outcome standards for conventional open cholecystectomy

Background Postcholecystectomy length of stay declined after the introduction of laparoscopy in 1987. Technology deserves some credit for reducing iatrogenic trauma. However, the improved outcome primarily resulted from setting higher surgical standards. What goals were (and are) achievable with the conventional “open” technique? Methods One surgeon performed 160 consecutive open cholecystectomies from 1983 to 1987. The patients averaged 46 years of age (range 13 to 100), 62% were female, and 20% presented acutely. Five (3.1%) had common bile duct exploration. Each patient was prepared to accept early discharge. Prompt ambulation followed minimal tissue handling and use of long-acting local anesthesia. Enteral feeding at 300 kcal plus 12 g AAs/ hour began immediately, with swallowed air and potential excess removed automatically by efficient more proximal aspiration. Results 160 patients were discharged the next day, 158 of 160 (99%) without receiving any narcotics. They absorbed (on average) 3,350 kcal plus 130 g AAs the initial 8 to 16 hours. Serum branched-chain amino acids (BCAA) levels rose above basal within 4 hours. Three patients (1.9%) were readmitted. One (0.6%) had a sterile biloma drained percutaneously. A single acute cholecystitis patient developed sepsis (0.6%), a subphrenic abscess that resolved after drainage. The sole mortality (0.6%) was caused suddenly 27 days postoperatively by a pulmonary embolus. Conclusions Laparoscopy is a valuable surgical tool whose actual incremental benefits are yet to be determined. Shorter length of stay after cholecystectomy may primarily reflect the altered expectations and overall improved surgical performance associated with this innovation.
Structural deformations and bond length alternation in porphyrin π-cation radicals

This review discusses the structural changes that occur when the porphyrin ring of metalloporphyrin complexes is oxidized to form a π-cation radical species. Although various differences in core conformation between the π-cation derivative and the unoxidized homologue have been observed, there does not appear to be a general pattern of change. A frequently observed feature in π-cation derivatives is the appearance of an alternating bond distance pattern in the inner ring of the porphyrin consistent with a localized structure rather the delocalized structure usually seen. The pattern, first seen in cofacial dimeric structures, has now been seen in monomeric systems as well. The nature and frequency of the observation and possible explanation are given.
Total Synthesis of Mycolactones A and B

First and second generation total syntheses of mycolactones A and B are reported. The first generation total synthesis unambiguously confirmed our earlier assignment of the relative and absolute stereochemistry of mycolactones A and B. Knowledge of the chemical properties of the mycolactones accumulated through the first generation total synthesis allowed us to implement several major improvements to the original synthesis, including: (1) optimizing the choice of protecting groups, (2) eliminating the unnecessary adjustment of protecting groups, and (3) improving the overall stereoselectivity and synthetic efficiency. The second generation total synthesis consists of 21 longest linear steps, with 8.8% overall yield.
Do remittances promote economic growth in the Caribbean Community and Common Market

Abstract The paper investigates the economic importance of remittance flows to the Caribbean Community and Common Market (CARICOM). Utilizing panel cointegration tests, the results show that there is no evidence of a long-run relationship between remittances and real GDP per capita or investment but some evidence of a long-run relationship between remittances and consumption. This suggests that remittance inflows to the CARICOM region are used for consumption purposes rather than productivity improving spending.
Inner-shell ionization of lithium-like chromium ions

We have used high-resolution x-ray spectroscopy to investigate inner-shell ionization of Cr21+ ions by electron impact using the Electron Beam Ion Trap at Lawrence Livermore Laboratory. Our measurements indicate that inner-shell ionization enhances the intensity of the radiative transition ls2s 3S1→1s2 1So.
On the Photometric Consequences of Charge‐Transfer Inefficiency in WFPC2

Charge-transfer effects in photometry with Wide Field Planetary Camera 2 (WFPC2) aboard the Hubble Space Telescope are investigated by a comparison of WFPC2 observations with ground-based photometry for the Galactic globular clusters ω Centauri and NGC 2419. Simple numerical formulae describing the fraction of lost signal as functions of position on the detector, stellar brightness, and the diffuse sky brightness recorded in an image are presented, and the resulting corrections are compared with those previously derived by Whitmore & Heyer. Significant lost-charge effects are seen that are proportional to both the Y-coordinate (i.e., the number of shifts along the parallel register during readout) and the X-coordinate (number of shifts along the serial register). A "typical" star image (one containing ~104 photoelectrons) near the center of a "typical" intermediate-length exposure (one with a diffuse sky brightness of ~10 e– pixel–1, obtained at a camera temperature of –88° C) loses approximately 2% of its electrons to charge traps during readout; a star in the corner of the image most remote from the readout electronics loses twice that. The percentage of charge lost decreases as the star brightness or the diffuse sky brightness increases. Charge losses during the brief period when WFPC2 was operated at a temperature of –76° C were approximately 85% greater, but apart from that, no significant change in the charge-transfer losses with time during the first 3.5 years of WFPC2's mission is evident, except possibly a weak effect for the very faintest star images. These results are quite similar to those of Whitmore & Heyer, which were based on a much smaller data set, but there are some differences in detail. Even with the present set of corrections, additional sources of calibration uncertainty that I am unable identify or characterize with the available data probably limit the external accuracy of photometry from WFPC2 to of order 1%-2%.
The role of terrestrial snow cover in the climate system

Snow cover is known to exert a strong influence on climate, but quantifying its impact is difficult. This study investigates the global impact of terrestrial snow cover through a pair of GCM simulations run with prognostic snow cover and with all snow cover on land eliminated (NOSNOWCOVER). In this experiment all snowfall over land was converted into its liquid–water equivalent upon reaching the surface. Compared with the control run, NOSNOWCOVER produces mean-annual surface air temperatures up to 5 K higher over northern North America and Eurasia and 8–10 K greater during winter. The globally averaged warming of 0.8 K is one-third as large as the model’s response to 2 × CO2 forcing. The pronounced surface heating propagates throughout the troposphere, causing changes in surface and upper-air circulation patterns. Despite the large atmospheric warming, the absence of an insulating snow pack causes soil temperatures in NOSNOWCOVER to fall throughout northern Asia and Canada, including extreme wintertime cooling of over 20 K in Siberia and a 70% increase in permafrost area. The absence of snow melt water also affects extratropical surface hydrology, causing significantly drier upper-layer soils and dramatic changes in the annual cycle of runoff. Removing snow cover also drastically affects extreme weather. Extreme cold-air outbreaks (CAOs)—defined relative to the control climatology—essentially disappear in NOSNOWCOVER. The loss of CAOs appears to stem from both the local effects of eliminating snow cover in mid-latitudes and a remote effect over source regions in the Arctic, where −40°C air masses are no longer able to form.
Optimal Flight-Path-Angle Transitions in Minimum-Time Airplane Climbs

If dependence of drag D on lift L is suppressed by calculating the induced drag corresponding to L weight W, the minimum-time climb path, obtained either by the energy state analysis or by Green's Theorem, leads, as is well known, to discontinuities in the flight-path angle 7. This requires, of course, an unreasonable increase in lift, positive or negative! If the reciprocal of maximum L/D is treated as a small parameter e, dependent on Mach number, a more complete analysis reveals that the discontinuities in 7 are replaced by transitional "boundary layers" on time scales of order e l / 2 , during which L/D is of order e ~ //: rather than e ~.
An Arg311Gln NR2E3 mutation in a family with classic Goldmann-Favre syndrome

Goldmann-Favre syndrome (GFS) is one of the rarest inherited vitreoretinal dystrophies that manifests with hemeralopia, degenerative vitreous changes, peripheral and central retinoschisis, a liquefied vitreous cavity with preretinal band-shaped structures, macular oedema, cataract formation, and an abnormal electroretinogram (ERG).1–3 The term “clumped pigmentary retinal degeneration” (CPRD) describes a group of patients with decreased night and peripheral vision who have round and irregular clumps of pigment in the mid-peripheral fundus with little or no evidence of bone spicule formation.4 This pattern of pigmentation occurs in retinitis pigmentosa (RP) with preserved para-arteriolar retinal pigment epithelium (PPRPE),5 enhanced S-cone syndrome (ESCS), and GFS, and these disorders share common mutations in the NR2E3 gene, which is involved in retinal cell fate determination.6 We present clinical and molecular genetic studies of a family from the United Arab Emirates with a classic GFS phenotype and a mutation in the NR2E3 gene. Two affected siblings and two unaffected siblings from a consanguineous family in which there were nine unaffected siblings were examined. GFS was diagnosed according to previous clinical descriptions of the disease.1,2 Complete ocular examinations, fluorescein angiography (FA), ERG, and optical coherence tomography (OCT) were …
Inorganic membranes and membrane reactors

The inorganic membrane reactor is a combined unit operation of chemical reactions and membrane separations. By having a membrane reactor, the downstream separation load can be reduced. Also, the yields can be increased and conversion can be improved for equilibrium limited reactions. However, many of the industrial chemical reactions take place at high temperature that the conventional polymeric membranes cannot withstand. A great deal of research has been done recently to develop ion-conducting ceramic membranes. Many of these have been successfully employed to form membrane reactors for many industrially relevant chemical reactions, such as hydrogenation, dehydrogenation, oxidation, coupled reactions, and decomposition reactions. An overview is given for the area of inorganic membrane preparations and membrane reactors. Many examples of petrochemical interests are presented, including hydrocarbon conversions and fuel cell applications.
Mechanical metamaterials with negative compressibility transitions

Most materials expand along the direction of an external pulling force, but there are no materials that compress instead. The proposal of mechanical metamaterials that show such negative compressibility promises new artificial materials with designed functionalities.
Therapeutic potential of targeting the oncogenic SHP2 phosphatase.

The Src homology 2 domain containing protein tyrosine phosphatase-2 (SHP2) is an oncogenic phosphatase associated with various kinds of leukemia and solid tumors. Thus, there is substantial interest in developing SHP2 inhibitors as potential anticancer and antileukemia agents. Using a structure-guided and fragment-based library approach, we identified a novel hydroxyindole carboxylic acid-based SHP2 inhibitor 11a-1, with an IC50 value of 200 nM and greater than 5-fold selectivity against 20 mammalian PTPs. Structural and modeling studies reveal that the hydroxyindole carboxylic acid anchors the inhibitor to the SHP2 active site, while interactions of the oxalamide linker and the phenylthiophene tail with residues in the β5–β6 loop contribute to 11a-1’s binding potency and selectivity. Evidence suggests that 11a-1 specifically attenuates the SHP2-dependent signaling inside the cell. Moreover, 11a-1 blocks growth factor mediated Erk1/2 and Akt activation and exhibits excellent antiproliferative activity in ...
Theoretical Radii of Extrasolar Giant Planets: The Cases of TrES-4, XO-3b, and HAT-P-1b

To explain their observed radii, we present theoretical radius-age trajectories for the extrasolar giant planets (EGPs) TrES-4, XO-3b, and HAT-P-1b. We factor in variations in atmospheric opacity, the presence of an inner heavy-element core, and possible heating due to orbital tidal dissipation. A small, yet nonzero, degree of core heating is needed to explain the observed radius of TrES-4, unless its atmospheric opacity is significantly larger than a value equivalent to that at -->10 × solar metallicity with equilibrium molecular abundances. This heating rate is reasonable, and corresponds for an energy dissipation parameter (Qp) of ~103.8 to an eccentricity of ~0.01, assuming -->3 × solar atmospheric opacity and a heavy-element core of -->Mc = 30 M⊕. For XO-3b, which has an observed orbital eccentricity of 0.26, we show that tidal heating needs to be taken into account to explain its observed radius. Furthermore, we reexamine the core mass needed for HAT-P-1b in light of new measurements and find that it now generally follows the correlation between stellar metallicity and core mass suggested recently. Given various core heating rates, theoretical grids and fitting formulae for a giant planet's equilibrium radius and equilibration timescale are provided for planet masses -->Mp = 0.5, 1.0, and 1.5 MJ with -->a = 0.02–0.06 AU, orbiting a G2 V star. When the equilibration timescale is much shorter than that of tidal heating variation, the effective age of the planet is shortened, resulting in evolutionary trajectories more like those of younger EGPs. Motivated by the work of B. Jackson et al., we suggest that this effect could indeed be important in better explaining some observed transit radii.
A matrix-Holzer analysis for bending vibrations of clustered launch vehicles.

Matrix-Holzer method for predicting free vibration modes of clustered launch vehicles in bending applied to first eight modes of Saturn I model
Frequency Veering Effects on Mistuned Bladed Disk Forced Response

Bladed disk mistuning is a significant contributor to gas-turbine high cycle fatigue. Frequency veering is known to increase bladed disk sensitivity to mistuning, but the reasons for the increased sensitivity are not well understood. The frequency veering effects on mistuned bladed disk forced response are investigated. Expressions for the forced response of a mistuned bladed disk with frequency veering are developed. These expressions are cast in a form that identifies the mechanisms through which frequency veering affects mistuned forced response. The accuracy of these expressions is then demonstrated by the use of two numerical examples. The first example allows for the direct observation of frequency veering effects on mistuned response. The second example demonstrates the applicability of the theoretical development to realistic bladed disk models.
New reagents for radical allylations

Abstract Three reagents are introduced for radical allylations: 3-phenylthio-2-bromopropene, 2,3-bis(trimethyl-stannyl)propene, and 3-tris(trimethylsilyl)silylthiopropene.
Interstitial fractionalization and spherical crystallography

Finding the ground states of identical particles packed on spheres has relevance for stabilizing emulsions and has a venerable history in the literature of theoretical physics and mathematics. Theory and experiment have confirmed that defects such as disclinations and dislocations are an intrinsic part of the ground state. Here we discuss the remarkable behavior of vacancies and interstitials in spherical crystals. The strain fields of isolated disclinations forced in by the spherical topology literally rip interstitials and vacancies apart, typically into dislocation fragments that combine with the disclinations to create small grain-boundary scars. The fractionalization is often into three charge-neutral dislocations, although dislocation pairs can be created as well. We use a powerful, freely-available computer program to explore interstitial fractionalization in some detail, for a variety of power-law pair potentials. We investigate the dependence on initial conditions and the final state energies, and compare the position dependence of interstitial energies with the predictions of continuum elastic theory on the sphere. The theory predicts that, before fragmentation, interstitials are repelled and vacancies are attracted from 5-fold disclinations. We also use vacancies and interstitials to study low-energy states in the vicinity of "magic numbers" that accommodate regular icosadeltahedral tessellations.
A New Bound on the Performance of the Bandwidth Puzzle

A bandwidth puzzle was recently proposed to defend against colluding adversaries in peer-to-peer networks. The colluding adversaries do not do actual work but claim to have uploaded content for each other to gain free credits from the system. The bandwidth puzzle guarantees that if the adversaries can solve the puzzles, they must have spent substantial bandwidth, the size of which is comparable to the size of the content they claim to have uploaded for each other. Therefore, the puzzle discourages the collusion. In this paper, we study the performance of the bandwidth puzzle and give a lower bound on the average number of bits the adversaries must receive to be able to solve the puzzles with a certain probability. We show that our bound is tight in the sense that there exists a strategy to approach this lower bound asymptotically within a small factor with practical puzzle parameters. The new bound gives better security guarantees than the existing bound, and can be used to guide the choices of puzzle parameters for practical systems.
The philosophy of automatic error correction

Automatic computing and dataprocessing equipment is depended upon today to perform a substantial portion of all data-processing requirements of government and industry in this country. It is natural, then, that the issue of reliability and the related issues of error detection and error correction have assumed a position of utmost importance from the viewpoint of users of such equipment. The manufacturers of data-processing equipment, recognizing the important role of their systems in the nation today, have likewise turned their attention to these areas and are bringing their most potent forces to bear on these vital issues.
A four-parameter partition identity

We present a new partition identity and give a combinatorial proof of our result. This generalizes a result of Andrews in which he considers the generating function for partitions with respect to size, number of odd parts, and number of odd parts of the conjugate.
Resolving singularities in (0,2) models

Abstract In contrast to the familiar (2,2) case, the singularities which arise in the (0,2) setting can be associated with degeneration of the base Calabi-Yau manifold and/or with degenerations of the gauge bundle. We study a variety of such singularities and give a procedure for resolving those which can be cured perturbatively. Among the novel features which emerge are models in which smoothing singularities in the base yields a gauge sheaf as opposed to a gauge bundle as the structure to which left-moving fermions couple. Supersymmetric σ-models with target data being an appropriate sheaf on a Calabi-Yau space therefore appear to be the natural arena for N = 1 string models in four dimensions. We also indicate a variety of singularities which would require a non-perturbative treatment for their resolution and briefly discuss applications to heterotic models on K3.
Chlorination of Aniline and Methyl Carbanilate by N-Chlorosuccinimide and Synthesis of 1,3,5-Trichlorobenzene

Aniline undergoes regioselective trichlorination by N-chlorosuccinimide (NCS) in acetonitrile in good yield. The product 2,4,6-trichoroaniline was converted into 1,3,5-trichlorobenzene by reduction of its diazonium salt. Reaction of the methyl carbamate of aniline with NCS gave only the 2,4-dichlorophenyl carbamate.
High speed hydraulic scanner for deep X-ray lithography

From our research and development in hard x-ray lithography, we have found that our conventional leadscrew driven scanner stages do not provide adequate scan speed or travel. These considerations have led us to develop a scanning system based on a long stroke hydraulic drive with 635 mm of travel and closed loop feedback to position the stage to better than 100 micrometers. The control of the device is through a PC with a custom LabView interface coupled to simple x-ray beam diagnostics. This configuration allows us to set a variety of scan parameters, including target dose, scan range, scan rates, and dose rate. Results from our prototype system at beamline X-27B are described as well as progress on a production version for the X-14B beamline.
The Effects of orbital motion on LISA time delay interferometry

In an effort to eliminate laser phase noise in laser interferometer spaceborne gravitational wave detectors, several combinations of signals have been found that allow the laser noise to be cancelled out while gravitational wave signals remain. This process is called time delay interferometry (TDI). In the papers that defined the TDI variables, their performance was evaluated in the limit that the gravitational wave detector is fixed in space. However, the performance depends on certain symmetries in the armlengths that are available if the detector is fixed in space, but that will be broken in the actual rotating and flexing configuration produced by the LISA orbits. In this paper we investigate the performance of these TDI variables for the real LISA orbits. First, addressing the effects of rotation, we verify Daniel Shaddock's result that the Sagnac variables α(t), β(t) and γ(t) will not cancel out the laser phase noise, and we also find the same result for the symmetric Sagnac variable ζ(t). The loss of the latter variable would be particularly unfortunate since this variable also cancels out gravitational wave signal, allowing instrument noise in the detector to be isolated and measured. Fortunately, we have found a set of more complicated TDI variables, which we call Δ-Sagnac variables, one of which accomplishes the same goal as ζ(t) to good accuracy. Finally, however, as we investigate the effects of the flexing of the detector arms due to non-circular orbital motion, we show that all variables, including the interferometer variables, X(t), Y(t) and Z(t), which survive the rotation-induced loss of direction symmetry, will not completely cancel laser phase noise when the armlengths are changing with time. This unavoidable problem will place a stringent requirement on laser stability of ~5 Hz Hz−1/2.
Interannual Variations in Upper-Ocean Heat Content and Heat Transport Convergence in the Western North Atlantic

Subsurface temperature data in the western North Atlantic Ocean are analyzed to study the variations in the heat content above a fixed isotherm and contributions from surface heat fluxes and oceanic processes. The study region is chosen based on the data density; its northern boundary shifts with the Gulf Stream position and its southern boundary shifts to contain constant volume. The temperature profiles are objectively mapped to a uniform grid (0.5° latitude and longitude, 10 m in depth, and 3 months in time). The interannual variations in upper-ocean heat content show good agreement with the changes in the sea surface height from the Ocean Topography Experiment (TOPEX)/Poseidon altimeter; both indicate positive anomalies in 1994 and 1998–99 and negative anomalies in 1996–97. The interannual variations in surface heat fluxes cannot explain the changes in upper-ocean heat storage rate. On the contrary, a positive anomaly in heat released to the atmosphere corresponds to a positive upper-ocean heat content anomaly. The oceanic heat transport, mainly owing to the geostrophic advection, controls the interannual variations in heat storage rate, which suggests that geostrophic advection plays an important role in the air–sea heat exchange. The 18°C isotherm depth and layer thickness also show good correspondence to the upper-ocean heat content; a deep and thin 18°C layer corresponds to a positive heat content anomaly. The oceanic transport in each isotherm layer shows an annual cycle, converging heat in winter, and diverging in summer in a warm layer; it also shows interannual variations with the largest heat convergence occurring in even warmer layers during the period of large ocean-to-atmosphere flux.
Flow induced by fire in a compartment

Fifty-five full-scale steady-state experiments were conducted to study the flow induced by a simulated pool fire in a compartment under conditions characteristic of the developing fire period. The mass flow rate through the door or window opening and bounds on the fire plume entrainment rate are presented as a function of opening geometry, fire strength, and fire location. The characteristics of the measured opening flow rates are explained by a simple hydrostatic model based on temperature distribution. A good correlation between the measured results and the idealized flows, taking into account the complete temperature distribution, is demonstrated. Entrainment results for fires near walls are in reasonable agreement with results from free-standing plume models. Except for the smallest openings, fires in other locations entrain at a rate two to three times the rate predicted by these models. This phenomenon is attributed to room disturbances caused by the opening flow and is similar to the behavior of a fire plume in a cross wind.
Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406 × 2.032 mm cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal that the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Annual flow is identified as the dominant flow pattern for conditions relevant to two-phase micro-channel heat sinks, and forms the basis for development of a theoretical model for both pressure drop and heat transfer in micro-channels. Features unique to two-phase micro-channel flow, such as laminar liquid and gas flows, smooth liquid-gas interface, and strong entrainment and deposition effects are incorporated into the model. The model shows good agreement with experimental data for water-cooled heat sinks.Copyright © 2003 by ASME
The simulation of building heat transfer for passive solar systems

Abstract A numerical simulation program, based upon a finite difference nodal network, was used to simulate two Los Alamos test cells (one single and one multi-room cell) and a typical residence — all of which were exposed to intense insolation and large changes in ambient weather conditions. For the test cells, the predicted surface and globe temperatures are in good agreement with the measured values and indicate the acceptability of thermal modeling. The program was used to predict the behavior of a residential structure. The process of refining these predictions, guided by observations, led to the development of a stepwise simulation methodology. The insights gained as a result of this interdisciplinary involvement have been stimulating and instructive. The importance of recognizing the differences in the thought processes and the work styles of the several professions has been demonstrated. The most effective simulation methodology was that based upon human comfort, which appeared to be a common perception amongst all the program users.
Involvement of rRNA synthesis in the enhanced survival and recovery of protein synthesis seen in thermotolerance

Although acquired thermotolerance has been linked to the induction of heat shock proteins, the molecular mechanism(s) by which cells become resistant to heat is unknown. The present study shows a strong correlation between the survival of cells following heat shock and the rate of recovery of protein, total RNA, and rRNA synthesis. Increasing exposure of CHO cells to 45 degrees C was found to decrease survival and cause a lengthening delay in these synthetic processes. The same reciprocal correlation was seen in thermotolerant cells. As thermotolerance develops, more cells survive a heat challenge and the delay in synthesis decreases. These data argue that enhanced recovery of protein and RNA synthesis is one factor which plays a key role in thermotolerance. The involvement of rRNA synthesis was further investigated by using actinomycin D at 0.1 microgram m1(-1), a concentration at which rRNA synthesis is selectively inhibited. When the drug was present during the recovery from a challenge heat treatment, the survival of thermotolerant cells was approximately 3-fold lower than expected from the mild toxicity of the drug. As this could not be accounted for by an interaction of the drug with the response of cells to single heat treatments, it is concluded that the drug inhibits the expression of thermotolerance in cells which would otherwise express a full degree of thermotolerance. The time and concentration dependence of this effect indicates that the drug acts though inhibition of rRNA synthesis. Therefore, enhanced recovery of RNA synthesis, presumably rRNA synthesis, is identified as one of the mechanisms responsible for enhanced survival of thermotolerant cells following heat shock.
What we can expect from interstate banking

Abstract Though interstate banking has been legislatively prohibited, commercial banks have circumvented these restrictions. This has led to proposals to permit interstate banking. In this paper we examine the performance of one set of banks which has been allowed to operate on an interstate basis, namely, those grandfathered by the Bank Holding Company Act of 1956. The data and statistical tests confirm that the grandfathered BHCs have experienced a statistically significant reduction in the share of state deposits and homogenization in their profitability and portfolio composition compared with their peers in the same states over the 1960–1983 period. These results suggest that the ability to operate banks interstate has provided little in the way of long-run competitive advantages for those BHCs with this privilege. It is unlikely that interstate branching will result in the large money center banks dominating local and regional banking markets.
Arginine and the Hofmeister Series: The Role of Ion-Ion Interactions in Protein Aggregation Suppression

l-Arginine hydrochloride is a very important aggregation suppressor for which there has been much attention given regarding elucidating its mechanism of action. Little consideration, however, has been given toward other salt forms besides chloride, even though the counterion likely imparts a large influence per the Hofmeister Series. Here, we report an in depth analysis of the role the counterion plays in the aggregation suppression behavior of arginine. Consistent with the empirical Hofmeister series, we found that the aggregation suppression ability of other arginine salt forms on a model protein (α-chymotrypsinogen) follows the order: H2PO4– > SO42– > citrate2– > acetate– ≈ F– ≈ Cl– > Br– > I– ≈ SCN–. Mechanistically, preferential interaction and osmotic virial coefficient measurements, in addition to molecular dynamics simulations, indicate that attractive ion–ion interactions, particularly attractive interactions between arginine molecules, play a dominate role in the observed behavior. Furthermore, ...
Postnatal Development of the Visual Cortex and the Influence of Environment.

In the early sixties, having begun to describe the physiology of ceils in the adult cat visual cor tex (1), David Hubel and I decided to invest igate how the highly specific response properties of cort ical cells emerged during postnatal development. We were also interested in e x a m i n i n g the rote of visual experience in normal development, a ques t ion ra i sed and d iscussed by philosophers since the t ime of Descartes . The design of these experiments was undoubtedly influenced by the observation that children with congenital ca ta rac t s still have substantial and often permanent visual deficits af ter removal of the ca ta rac t and proper refract ion (2). Also, behavioral studies had shown that animals raised in the dark or in an environment devoid of contours have a similar impairment of their visual functions (3,4). Because of the difficulties associated with raising kittens in total da rkness , we decided to fuse the lids by suture. This procedure p r e v e n t e d any fo rm vision wi thout completely light-depriving the an imal . We e x p e c t e d this to be an e f fec t ive procedure because cort ical ceils respond to contours and are insensitive to changes in levels of diffuse light (5) . Initially we raised kittens with only one eye closed, using the other eye as a control. This design turned out to be for tunate , because as shown below the e f fec t s of single eye c lo s u re on the visual cor tex are more dramatic than the results obtained from animals raised with both eyes occluded or kept in the dark. Our initial findings were that kittens with an eye occluded by lid suture during the first three months of life were blind in the deprived eye, and that in the s t r ia te cor tex the majority of the cells responded only to stimulation of the normal eye (6). This defect appeared to be localized to the visual cortex, perhaps at the site of interact ion between geniculate afferents and cortical cells (7) . From another series of experiments, we found that the properties of orientat ion specif ic i ty and binocularity developed through innate mechanisms (8) . This result, taken together with the monocular deprivation experiment, i nd ica t ed that neural connections present early in life can be modified by visual experience. Such neural plasticity was not observed in the adult cat , but existed only during the first three postnatal months (9). The early experiments were done in the cat, but we soon turned our at tent ion to the rhesus macaque monkey. After having demons t ra ted that cells in the monkey visual cor tex also respond select ively to lines of different orientations and often are binocular (10), we
On near forward high energy scattering in QCD

Abstract We consider elastic quark-quark scattering at high energy and fixed transferred momentum. Performing factorization of soft gluon exchanges into Wilson lines vacuum expectation values and studying their properties, we find that the asymptotics of the scattering amplitude is controlled by the renormalization properties of the so called cross singularities of Wilson loops. Using this fact, we evaluate the scattering amplitude and show that its asymptotics is determined by the properties of the 2 × 2 matrix of anomalous dimensions which appears after renormalization of the cross singularities of Wilson loops. A generalization to the case of quark-antiquark and gluon-gluon elastic scattering is discussed.
Acoustic sensor networks for woodpecker localization

Sensor network technology can revolutionize the study of animal ecology by providing a means of non-intrusive, simultaneous monitoring of interaction among multiple animals. In this paper, we investigate design, analysis, and testing of acoustic arrays for localizing acorn woodpeckers using their vocalizations. Each acoustic array consists of four microphones arranged in a square. All four audio channels within the same acoustic array are finely synchronized within a few micro seconds. We apply the approximate maximum likelihood (AML) method to synchronized audio channels of each acoustic array for estimating the direction-of-arrival (DOA) of woodpecker vocalizations. The woodpecker location is estimated by applying least square (LS) methods to DOA bearing crossings of multiple acoustic arrays. We have revealed the critical relation between microphone spacing of acoustic arrays and robustness of beamforming of woodpecker vocalizations. Woodpecker localization experiments using robust array element spacing in different types of environments are conducted and compared. Practical issues about calibration of acoustic array orientation are also discussed.
Observability and nonlinear filtering

This paper develops a connection between the asymptotic stability of nonlinear filters and a notion of observability. We consider a general class of hidden Markov models in continuous time with compact signal state space, and call such a model observable if no two initial measures of the signal process give rise to the same law of the observation process. We demonstrate that observability implies stability of the filter, i.e., the filtered estimates become insensitive to the initial measure at large times. For the special case where the signal is a finite-state Markov process and the observations are of the white noise type, a complete (necessary and sufficient) characterization of filter stability is obtained in terms of a slightly weaker detectability condition. In addition to observability, the role of controllability is explored. Finally, the results are partially extended to non-compact signal state spaces.
Two new methods for 2,3-Pyridyne formation

Abstract The compounds 2-chloro-4-methoxypyridine and 4-methoxy-2-trifluoromethylsulfonyloxy-3-trimethylsilylpyridine were shown to be relatively efficient precursors for 4-methoxy-2,3-pyridyne as was evidenced by its trapping with furan, 2-methylfuran and 2-methoxyfuran. These findings constitute the first published report of the use of either directed-deprotonation or fluoride-induced elimination to prepare the reactive 2,3-pyridyne intermediate.
MEASUREMENTS OF SUPERSONIC WING TIP VORTICES

An experimental study of supersonic wing tip vortices has been conducted at Mach 2.49 using small-scale four-hole and five-hole conical probes, The study was performed 2.25 chords downstream of a semispan rectangular wing at angles of attack of 5.7 and 10.4 deg. The main objective of the experiments was to determine the Mach number, flow angularity and total pressure distribution in the core region of supersonic wing tip vortices. A secondary aim was to demonstrate the feasibility of calibrating a conical probe using a computational solution to predict the flow characteristics. Results of the present investigation showed that the numerically generated calibration data can be used for pointed nose four-hole conical probes but were not sufficiently accurate for conventional five-hole probes due to nose bluntness effects. A combination of four-hole conical probe measurements with independent pitot pressure measurements indicated a significant Mach number and total pressure deficit in the core regions of supersonic wing tip vortices, combined with an asymmetric ''Burger-like'' swirl distribution.
Vibrational entropy of spinodal decomposition in FeCr

Inelastic neutron-scattering spectra were measured on stoichiometric Fe0.50Cr0.50 prepared as a body-centered-cubic (bcc) solid solution, and after increasing amounts of chemical unmixing on the bcc lattice induced by annealing the solid solution at 773 K. These spectra were reduced by a conventional procedure to a neutron-weighted vibrational density of states. Mossbauer spectrometry was used to characterize the extent of decomposition after annealing. A neutron-weight correction was performed, using results from the Mossbauer spectra and recent data on inelastic nuclear resonant scattering from 57Fe-Cr. The vibrational entropy of decomposition was found to be –0.17±0.01kB/atom, nearly equal to the change in configurational entropy after spinodal decomposition. Effects of vibrational entropy on the thermodynamics of unmixing are analyzed, showing a large effect on the free energy with the formation of Cr-rich zones, and a large effect on the critical temperature for spinodal decomposition for equiatomic Fe0.50Cr0.50.