cssi/SciSciGPT-SciSciNet huggingface dataset:
Surface-induced reduction of twisting power in liquid-crystal films

Null transmission ellipsometry was employed to study the temperature evolution of the helical structure of the smectic-$C$${}_{\ensuremath{\alpha}}^{*}$ phase. Free-standing films with thickness ranging from 31 to more than 400 layers were prepared and studied. The experimental results show a reduced twisting power in thin films. A simple model was constructed to explain the results. Surface effects were found to be the key reason for this phenomenon. Our findings are consistent with the theoretical studies of helically ordered magnetic films.
Competitive Target Advertising and Consumer Data Sharing

Advances in information technologies enable firms to collect detailed consumer data and target individual consumers with tailored ads. Consumer data are among the most valuable assets that firms own. An interesting phenomenon is that competing firms often trade their consumer data with each other. Based on a common-value all-pay auction framework, this paper studies the advertising competition between two firms that target the same consumer but are asymmetrically informed about the consumer value. We characterize firms' equilibrium competition strategies. The results show that better consumer information does not help the better-informed firm save the advertising expenditure but does enable it to reap a higher expected profit in competition. Sharing individual-level consumer data may soften the competition even though firms compete head-to-head for the same consumer. We also find that the better-informed firm may sell its data to its competitor but never voluntarily shares it with its competitor.
The demand for health inputs and their impact on the black neonatal mortality rate in the U.S.

Abstract Relatively high birth rates among black adolescents and unmarried women as well as inadequate access to medical care are considered primary reasons why the black neonatal mortality rate is almost double that of whites. Using household production theory, this paper examines the determinants of input utilization and estimates the impact of utilization on the survival of black infants across large countries in the U.S. in 1977. The results indicate that expanding the availability of family planning clinics increases the number of teenagers served resulting in a lower neonatal mortality rate. Accessibility to abortion services operates in a similar manner. Moreover, the use of neonatal intensive care, which is strongly related to its availability, is an important determinant of newborn survivability whereas the initiation of early prenatal care is not. Overall, the results suggest that lowering the incidence of low-weight and preterm births among blacks by helping women to avoid an unwanted birth, may be the most cost-effective way of improving black infant health.
Improving TCP performance over networks with wireless components using ‘probing devices’

TCP error control mechanism lacks the ability to detect with precision the nature of potential errors during communication. It is only capable of detecting the results of the errors, namely that segments are dropped. As a result, the protocol lacks the ability to implement an appropriate error recovery strategy cognizant of current network conditions and responsive to the distinctive error characteristics of the communication channel. TCP sender always calls for the sending window to shrink. We show that probing mechanisms could enhance the error detection capabilities of the protocol. TCP could then flexibly adjust its window in a manner that permits the available bandwidth to be exploited without violating the requirements of stability, efficiency and fairness that need to be guaranteed during congestion. Our experiments have three distinct goals: First, to demonstrate the potential contribution of probing mechanisms. A simple probing mechanism and an immediate recovery strategy are grafted into TCP-Tahoe and TCP-Reno. We show that, this way, standard TCP can improve its performance without requiring any further change. Second, to study the performance of adaptive strategies. An adaptive TCP with probing is used, that is responsive to the detected error conditions by alternating slow start, fast recovery and immediate recovery. An adaptive error recovery strategy can yield better performance. Third, to study the design limitations of the probing device itself. The aggressive or conservative nature of the probing mechanisms themselves can determine the aggressive or conservative behaviour of the protocol and exploit accordingly the energy/throughput trade-off. Copyright © 2002 John Wiley & Sons, Ltd.
A decision support system for computer-aided process planning

Abstract A decision support system framework is presented to aid the Decision Maker to resolve conflicting, non-commensurate objectives to set up parameters for machining operations, using a Multiple Criteria Decision Making approach.
Global upper-mantle structure from finite-frequency surface-wave tomography

[1] We report global shear-wave velocity structure and radial anisotropy in the upper mantle obtained using finite-frequency surface-wave tomography, based upon complete three-dimensional Born sensitivity kernels. Because wavefront healing effects are properly taken into account, finite-frequency surface-wave tomography improves the resolution of small-scale mantle heterogeneities, especially for deep anomalies that are constrained by the longest-period surface waves. In our finite-frequency model FFSW1, the globally averaged radial anisotropy shows a transition from positive (SH > SV) to negative anisotropy (SV > SH) at about 220 km, consistent with a change in the dominant mantle circulation pattern from predominantly horizontal flow at shallow depths to vertical flow at greater depths. The radial anisotropy beneath cratons and the old Pacific plate agrees well with previous studies. However, our model exhibits a strong negative radial anisotropy at depths greater than 120 km beneath mid-ocean ridges, a feature that is not present in previous upper-mantle models. More interestingly, the depth extent of the ridge anomalies is distinctly different beneath fast- and slow-spreading centers; anomalies beneath fast-spreading centers are stronger, but the strength decreases rapidly below 250 km. In contrast, beneath slow-spreading centers such as the northern Mid-Atlantic Ridge and the Red Sea, anomalies extend down at least to the top of the transition zone. The different depth extent of the ridge anomalies suggests that the primary driving force of slow-spreading seafloor may be different from that of fast-spreading seafloor and that active upwelling beneath slow-spreading ridges may play a major role in the opening of the seafloor.
Bias in GRACE estimates of ice mass change due to accompanying sea-level change

Observations of spatio-temporal variations in the geopotential using the GRACE satellites have been used to estimate recent mass fluxes from polar ice sheets and glaciers. However, these estimates have not considered the potential bias associated with the migration of water that accompanies the ice melt. This migration is driven by the diminished gravitational attraction of the melting ice reservoir, and this migration, as well as the crustal loading it induces, will contribute to the observed geopotential anomaly. The extent to which this contribution contaminates the ice mass flux estimates depends on how far the smoothing filters applied to the GRACE data extend beyond the ice margins into the ocean. Using the Antarctic Peninsula as a case study, we estimate the magnitude of this bias for a range of melt areas and Gaussian smoothing filter radii. We conclude that GRACE estimates of ice mass loss over the Antarctic Peninsula are systematically overestimating the loss by up to 10 $$\%$$ for filter radii of less than 500 km.
Housing issues of persons with AIDS.

The housing status of persons with HIV/AIDS is a central issue in their care and prognosis. We conducted eight focus groups to explore the housing needs of special populations of persons with HIV/AIDS in New York State; these populations included substance users, ex-offenders, persons with documented histories of homelessness, and rural dwellers/migrant workers. For the focus groups, 52 participants were recruited from the clientele of health and social service agencies. A major theme was the potent effect that housing situations had on participants’ health. Participants frequently attributed lowered T-cell counts and increased lethargy to the stress associated with governmental rules and paperwork. Lack of money, inadequacy of entitlements, and high costs of housing were the major barriers to securing stable and appropriate housing. Furthermore, participants experienced housing discrimination based on HIV status and experience with the criminal justice system or drugs.
Optimal image interpolation using local low-order surfaces

Desirable features of any digital image resolution- enhancement algorithm include exact interpolation (for 'distortionless' or 'lossless' processing) adjustable resolution, adjustable smoothness, and ease of computation. A given low-order polynomial surface (linear, quadratic, cubic, etc.) optimally fit by least squares to a given local neighborhood of a pixel to be interpolated can enable all of these features. For example, if the surface is cubic, if a pixel and the 5-by-5 pixel array surrounding it are selected, and if interpolation of this pixel must yield a 4- by-4 array of sub-pixels, then the 10 coefficients that define the surface may be determined by the constrained least squares solution of 25 linear equations in 10 unknowns, where each equation sets the surface value at a pixel center equal to the pixel gray value and where the constraint is that the mean of the surface values at the sub-pixel centers equals the gray value of the interpolated pixel. Note that resolution is adjustable because the interpolating surface for each pixel may be subdivided arbitrarily, that smoothness is adjustable (within each pixel) because the polynomial order and number neighboring pixels may be selected, and that the most computationally demanding operation is solving a relatively small number of simultaneous linear equations for each pixel.
Micro‐/Nanostructured Mechanical Metamaterials

Mechanical properties of materials have long been one of the most fundamental and studied areas of materials science for a myriad of applications. Recently, mechanical metamaterials have been shown to possess extraordinary effective properties, such as negative dynamic modulus and/or density, phononic bandgaps, superior thermoelectric properties, and high specific energy absorption. To obtain such materials on appropriate length scales to enable novel mechanical devices, it is often necessary to effectively design and fabricate micro-/nano- structured materials. In this Review, various aspects of the micro-/nano-structured materials as mechanical metamaterials, potential tools for their multidimensional fabrication, and selected methods for their structural and performance characterization are described, as well as some prospects for the future developments in this exciting and emerging field.
Economic agents and markets as emergent phenomena.

An overview of recent work in agent-based computational economics is provided, with a stress on the research areas highlighted in the National Academy of Sciences Sackler Colloquium session “Economic Agents and Markets as Emergent Phenomena” held in October 2001.
Reduced mass calculations, low-frequency vibrations, and conformations of 1,4-cyclohexadiene, 1,4-dioxacyclohexadiene-2,5, and 9,10-dihydroanthracene

Abstract Vector-based computer programs have been written in order to calculate the kinetic energy (reciprocal reduced mass) expansions as a function of the coordinate for the ring-puckering, ring-twisting (in-phase), and ring-twisting (out-of-phase) vibrations of 9,10-dihydroanthracene. The same programs also permit the kinetic energy expansions for all three vibrations to be calculated for smaller molecules including 1,4-cyclohexadiene and 1,4-dioxacyclohexadiene-2,5. The reduced mass calculated for the ring-puckering vibration of 1,4-cyclohexadiene has a minimum value for the planar conformation and increases substantially as the molecule puckers. The kinetic energy expansion for this vibration, used along with a harmonic ring-puckering potential energy function, quantitatively accounts for the observed far-infrared spectrum. This molecule is thus clearly planar. The potential energy function for 1,4-cyclohexadiene calculated from a molecular mechanics program does a remarkable job in predicting the ring-puckering frequencies when the calculated reduced mass expansion is used. The kinetic energy expansions for the puckering and twisting vibrations of 1,4-dioxacyclohexadiene-2,5 and 9,10-dihydroanthracene have also been used in conjunction with potential functions to help analyze the observed spectra for these molecules.
Treatment of severe IgA nephropathy in children.

We treated ten children with severe IgA nephropathy (IgAN) [proteinuria > 1g/day, hypertension, renal insufficiency, segmental sclerosis, crescent formation and/or glomerular basement membrane (GBM) deposition of IgA] with prednisone and azathioprine for 1 year. Following the year of therapy, seven of the ten children underwent a repeat kidney biopsy. All biopsies were scored for activity (percentage of glomeruli demonstrating crescent formation, degree of mesangial proliferation and interstitial infiltrate; maximum score = 9) and chronicity (percentage of glomeruli demonstrating fibrous crescents, segmental sclerosis, global sclerosis, and degree of tubular atrophy and interstitial fibrosis; maximum score = 12). After 1 year of therapy, the protein excretion of all the children decreased significantly (P<0.01) from 4052±3190 mg/day to 1692±1634 mg/day. The activity score decreased significantly (P<0.01) from 4.35±0.94 prior to therapy to 2.28±0.75 after therapy while the chronicity score was unchanged (5.42±1.7 vs 5.85±2.0). The percentage of glomeruli demonstrating cellular crescents decreased (P<0.05) from 21.2±21.7% prior to therapy to 0.94±2.4% after therapy. Mesangial deposition of IgA persisted but GBM deposition of IgA was less prominent after therapy. During the follow-up period (mean 2.6 years, range 9 months–7.5 years), one child required brief retreatment for biopsy-confirmed recurrence of active disease, two children have developed renal insufficiency due to progressive scarring in the absence of inflammation, while the remaining seven are stable. We suggest that treatment with prednisone and azathioprine may be beneficial in children with severe IgAN and that a controlled clinical trial is warranted.
Lack of Effect Following Repeated In Vivo Exposure of the Rabbit Urinary Bladder to Urine From Interstitial Cystitis Patients at Low Infusion Volumes

We reported previously that substances in interstitial cystitis urine, when infused into the rabbit bladder, induce changes that resemble bladders of interstitial cystitis (IC) patients. Here we report our investigation of the effect of additional molecular weight subfractions of IC urine and lower infusion volume in this rabbit bladder bioassay. Urine was pooled from symptomatic IC patients, asymptomatic IC patients (in remission), and normal volunteers. Two fractions of 20◊ concentrated urine were obtained for each of the 3 groups: a 10‐100-kD fraction and a fraction > 100 kD but <0.22 mm. Six rabbits per group were infused twice per week with 6 ml of 1 of these 6 urine fractions or saline as a control. After 6 weeks, each rabbit was cystoscoped before and after hydrodistension, bladder capacity and urea permeability were determined, and the bladder was removed for histologic examination. A questionnaire revealed a significant difference ( P < 0.01) regarding voiding symptom severity between symptomatic IC patients and both normal volunteers and IC patients in remission. There was no statistically significant difference among groups of rabbits in cystoscopic bladder appearance, bladder capacity, urea permeability, or bladder histology. If a urine-borne factor is in part responsible for IC symptoms, the rabbit bladder must be filled with urine to near capacity to be able to detect a difference between IC and normal urine in this rabbit bladder bioassay. Neurourol. Urodynam. 17:147‐152, 1998. © 1998 Wiley-Liss, Inc.
Bounds on the complexity of recurrent neural network implementations of finite state machines

Abstract In this paper the efficiency of recurrent neural network implementations of m-state finite state machines will be explored. Specifically, it will be shown that the node complexity for the unrestricted case can be bounded above by O (√ m ). It will also be shown that the node complexity is O( m log m ) when the weights and thresholds are restricted to the set {−1,1} and O(m) when the fan-in is restricted to two. Matching lower bounds will be provided for each of these upper bounds assuming that the state of the FSM can be encoded in a subset of the nodes of size [ log m].
Sciduction: combining induction, deduction, and structure for verification and synthesis

Even with impressive advances in formal verification, certain major challenges remain. Chief amongst these are environment modeling, incompleteness in specifications, and the complexity of underlying decision problems. In this position paper, we contend that these challenges can be tackled by integrating traditional, deductive methods with inductive inference (learning from examples) using hypotheses about system structure. We present sciduction, a formalization of such an integration, show how it can tackle hard problems in verification and synthesis, and outline directions for future work.
Electromagnetic properties of iron oxide corrosion product powders at radio frequencies

We calculated the refractive index from Sparameter data for corrosion samples tested in waveguide from 12.4 GHz to 110 GHz. This approach minimizes the modal noise often seen in derived permittivity and permeability for low-loss samples in this range. Also, any resonance absorption due to atomic structure is made clearly discernible. We are interested in observing spectral signatures with network analyzer measurements to quantify corrosion in reinforcing steel embedded in concrete. Here, we report room-temperature measurements of the refractive index for magnetite, maghemite, goethite, hematite, calcium ferroaluminate, and bridge girder corrosion powders, all of which exhibit flat spectral responses.
Novel Urchin-like CuO Synthesized by a Facile Reflux Method with Efficient Olefin Epoxidation Catalytic Performance

CuO is an important transition metal oxide with a narrow bandgap (Eg = 1.2 eV). CuO has been used as a catalyst, a gas sensor, in anode materials for Li ion batteries. CuO has also been used to prepare high temperature superconductors and magnetoresistance materials. In this paper, CuO with urchin-like morphologies has been synthesized via a simple reflux method. The reflux method has advantages over other solution-based techniques, such as ease of operation, safety, and high yield (95%). XRD results showed pure tenorite CuO was produced. FE-SEM exhibited an urchin-like morphology of CuO, which is composed of aggregates of nanosized strips. HR-TEM showed that the strips were single crystals with the lattice fringe of 2.3 A, which corresponds to (111). DSC and TGA results suggested that as-synthesized CuO had high thermal stability. Time-dependent experiments were conducted to illustrate the evolution of the urchin-like morphology and crystal phase formation of CuO. The effects of copper sources and precip...
Ionization Front Instabilities in Primordial H II Regions

Radiative cooling by metals in shocked gas mediates the formation of ionization front instabilities in the galaxy today that are responsible for a variety of phenomena in the interstellar medium, from the morphologies of nebulae to triggered star formation in molecular clouds. An important question in early reionization and chemical enrichment of the intergalactic medium is whether such instabilities arose in the H II regions of the first stars and primeval galaxies, which were devoid of metals. We present three-dimensional numerical simulations that reveal both shadow and thin-shell instabilities readily formed in primordial gas. We find that the hard UV spectra of Population III stars broadened primordial ionization fronts, causing H2 formation capable of inciting violent thin-shell instabilities in D-type fronts, even in the presence of intense Lyman-Werner flux. The high postfront gas temperatures associated with He ionization sustained and exacerbated shadow instabilities, unaided by molecular hydrogen cooling. Our models indicate that metals eclipsed H2 cooling in I-front instabilities at modest concentrations, from 1 × 10−3 to 1 × 10−2 Z☉. We conclude that ionization front instabilities were prominent in the H II regions of the first stars and galaxies, influencing the escape of ionizing radiation and metals into the early universe.
An investigation of substituent effects on the conformation of 9,10-dihydroanthracenes by molecular mechanics calculations and X-ray structure analysis

Abstract MM2 calculations for a series of 9-R-9,10-dihydroanthracenes (DHAs) and cis-9-R-10-R′-9,10-dihydroanthracenes were performed to investigate the effect of substituents on the geometry of the central ring in 9,10-dihydroanthracenes. In general, the observed variation in central ring folding as compared to 9,10-dihydroanthracene itself is rather small for the monosubstituted compounds, but is quite pronounced for the cis-9-R-10-R′ disubstituted deriviatives. These variations in conformational preferences are rationalized in terms of the 1,4 transannular effect of substituents across the ring, and by the peri interaction between the substituents and the neighboring aromatic hydrogens. X-ray structure determinations on two monosubstituted compounds, 9-Me-DHA and 9-SiMe3-DHA, and two disubstituted compounds, cis-9-SiMe3-10-Me-DHA and 9-SiMe3-10-iPr-DHA, provide strong support for the validity of the calculations in predicting optimum structures for monosubstituted and cis-disubstituted DHAs.
Does returning to work after childbirth affect breastfeeding practices

This study examines the effect of the timing and intensity of returning to work after childbirth on the probability of initiating breastfeeding and the number of weeks of breastfeeding. Data come from the National Longitudinal Survey of Youth (NLSY79). Baseline probit models and family-level fixed effects models indicate that returning to work within 3 months is associated with a reduction in the probability that the mother will initiate breastfeeding by 16–18%. Among those mothers who initiate breastfeeding, returning to work within 3 months is associated with a reduction in the length of breastfeeding of 4–5 weeks. We find less consistent evidence that working at least 35 h per week (among mothers who return to work within 3 months) detracts from breastfeeding. Future research is needed on understanding how employers can design policies and workplaces that support breastfeeding.
ORDERING KINETICS OF DEFECT STRUCTURES

We show how the continuity equations expressing conservation of topological point or string defect charge can be used to determine the order-parameter correlation function for the phase-ordering kinetics of the O(n) model in the special case where the order parameter is constrained to be near a defect core. In this regime we find a self-consistent solution by assuming the order parameter is Gaussian. The resulting linear equation for the order-parameter correlation function has as its solution the Ohta-Jasnow-Kawasaki form.
Radio Emission Signatures in the Crab Pulsar

Our high time resolution observations of individual pulses from the Crab pulsar show that both the time and frequency signatures of the interpulse are distinctly different from those of the main pulse. Main pulses can occasionally be resolved into short-lived, relatively narrowband nanoshots. We believe these nanoshots are produced by soliton collapse in strong plasma turbulence. Interpulses at centimeter wavelengths are very different. Their dynamic spectrum contains regular, microsecond-long emission bands. We have detected these bands, proportionately spaced in frequency, from 4.5 to 10.5 GHz. The bands cannot easily be explained by any current theory of pulsar radio emission; we speculate on possible new models.
Multi-Rate Feedforward Tracking Control for Plants With Nonminimum Phase Discrete Time Models

This paper deals with performance enhancement of tracking control systems by multi-rate control. The feedback controller is updated at the same rate as the sampling rate of the output measurements. The feedforward controller processes the desired output signal for high accuracy tracking, and its output is updated at a rate N-times faster than the sampling rate of the output measurements. The discrete time model of the controlled plant may possess unstable zeros, and the zero phase error tracking controller is used as a feedforward controller. Inter-sample behavior of the plant is included in evaluating the tracking performance of the multi-rate system. Illustrative examples are given to show advantages of the proposed multi-rate feedback/feedforward control scheme.
Substituted 2,2'-bipyridines by nickel-catalysis: 4,4'-di-tert-butyl-2,2'-bipyridine.

A simple, ligand-free synthesis of the important bipyridyl ligand 4,4′-di-tert-butyl-2,2′-bipyridine is presented. 5,5′-Bis(trifluoromethyl)-2,2′-bipyridine is also synthesized by the same protocol. The syntheses efficiently couple the parent 2-chloropyridines by a nickel-catalyzed dimerization with manganese powder as the terminal reductant.
Continuum description of avalanches in granular media

We develop a continuum description of partially fluidized granular flows. Our theory is based on the hydrodynamic equation for the flow coupled with the order parameter equation, which describes the transition between flowing and static components of the granular system. This theory captures important phenomenology recently observed in experiments with granular flows on rough inclined planes [A. Daerr and S. Douady, Nature (London) 399, 241 (1999)]: layer bistability, and transition from triangular avalanches propagating downhill at small inclination angles to balloon-shaped avalanches also propagating uphill for larger angles.
The capacity for self-governance and post-disaster resiliency

A community’s capacity for self-governance depends on the social coordination capacity of community organizations and associations, the ability of community members to effectively access both bonding and bridging social capital, the ability of community members to leverage their shared histories and perspectives, and the stability of social networks within the community. Both Elinor Ostrom and Jane Jacobs have explored how a community’s capacity for self-governance affects its ability to solve complex problems (for example, dealing with crime, the provision of public goods, or problems of neighborhood blight). The greater a community’s capacity for self-governance the better able it is to deal with these complex challenges. This paper examines how pre-disaster systems of self-governance aid in post-disaster community recovery. Our analysis focuses on the Mary Queen of Vietnam (MQVN) community and Gentilly, examines the effectiveness of their systems of self-governance prior to Hurricane Katrina and explores the role these systems played in promoting community recovery after the disaster.
A review of technology-assisted self-help and minimal contact therapies for anxiety and depression: Is human contact necessary for therapeutic efficacy?

Technology-based self-help and minimal contact therapies have been proposed as effective and low-cost interventions for anxiety and mood disorders. The present article reviews the literature published before 2010 on these treatments for anxiety and depression using self-help and decreased therapist-contact interventions. Treatment studies are examined by disorder as well as amount of therapist contact, ranging from self-administered therapy and predominantly self-help interventions to minimal contact therapy where the therapist is actively involved in treatment but to a lesser degree than traditional therapy and predominantly therapist-administered treatments involving regular contact with a therapist for a typical number of sessions. In the treatment of anxiety disorders, it is concluded that self-administered and predominantly self-help interventions are most effective for motivated clients. Conversely, minimal-contact therapies have demonstrated efficacy for the greatest variety of anxiety diagnoses when accounting for both attrition and compliance. Additionally, predominantly self-help computer-based cognitive and behavioral interventions are efficacious in the treatment of subthreshold mood disorders. However, therapist-assisted treatments remain optimal in the treatment of clinical levels of depression. Although the most efficacious amount of therapist contact varies by disorder, computerized treatments have been shown to be a less-intensive, cost-effective way to deliver empirically validated treatments for a variety of psychological problems.
Genesis of the Angra dos Reis and other achondritic meteorites

Major, minor, and trace element abundances were determined in seven Angra dos Reis samples, which included whole rocks, fassaite (clinopyroxene), olivine, and whitlockite separates, via sequential instrumental neutron activation analysis. The rare earth element abundance patterns and the trace element abundance patterns of this achondritic meteorite are discussed. A two-stage crystal-liquid fractionation model with source material containing olivine, orthopyroxene, and clinopyroxine is presented for the genesis of Angra dos Reis. Multilinear regression analysis was used to estimate possible composition and properties of the parent magmas. Angra dos Reis was compared with other achondrites, cumulate eucrites and nakhlites in particular. It is thought that the unique Angra dos Reis could not be related to those achondrites by crystal-liquid fractionation of the same parent body.
Natural circulation patterns in the VHTR air-ingress accident and related issues

Abstract Natural circulation patterns in the VHTR during a hypothetical air-ingress accident have been investigated using computational fluid dynamic (CFD) methods in order to compare results from the previous 1-D model which was developed using GAMMA code for the air-ingress analyses. The GT-MHR 600 MWt reactor was selected to be the reference design and modeled by a half symmetric 3-D geometry using FLUENT 6.3, a commercial CFD code. CFD simulations were carried out as the steady-state calculation, and the boundary conditions were either assumed or provided from the 1-D GAMMA code results. Totally, 12 different cases have been reviewed, and many notable results have been obtained through this work. According to the simulations, natural circulation patterns in the reactor were quite different from the previous 1-D assumptions. A large re-circulation flow with thermal stratification phenomena was clearly observed in the hot-leg and the lower plenum in the 3-D model. This re-circulation flow provided about an order faster air-ingress speed (0.46 m/s in superficial velocity) than previously predicted by 1-D modeling (0.02–0.03 m/s). It indicates that the 1-D air-ingress modeling may significantly distort the air-ingress scenario and consequences. In addition, complicated natural circulation patterns are eventually expected to result in very complex graphite oxidations and corrosion behaviors.
A randomized trial of intrapartum analgesia in women with severe preeclampsia.

Abstract OBJECTIVE: To estimate whether the cesarean delivery rate differs between women with severe preeclampsia who receive intrapartum epidural analgesia versus patient-controlled intravenous opioid analgesia. METHODS: Women with severe preeclampsia at at least 24 weeks’ gestation were randomly assigned to receive either intrapartum epidural (n = 56) versus patient-controlled intravenous opioid analgesia (n = 60), and each was administered by a standardized protocol. The sample size was selected to have 80% power to detect at least a 50% difference in the predicted intergroup cesarean delivery rates. Data were analyzed by intent to treat. RESULTS: Selected maternal characteristics and neonatal outcomes were similar in the two groups. The cesarean delivery rates in the epidural group (18%) and the patient-controlled analgesia group (12%) were similar (P = .35). Women who received epidural analgesia were more likely to require ephedrine for the treatment of hypotension (9% versus 0%, P = .02), but their infants were less likely to require naloxone at delivery (9% versus 54%, P CONCLUSION: Compared with patient-controlled intravenous opioid analgesia, intrapartum epidural analgesia did not significantly increase the cesarean delivery rate in women with severe preeclampsia at our level III center, and it provided superior pain relief.
Structural characterization of bis(arylimino)isoindoline complexes of dimolybdenum

Abstract The complexes [Mo2(OAc)3(BAII)], where BAII is either bis(pyridylimino) isoindoline or bis(4,6-dimethylpyridylimino)isoindoline, have been synthesized. A detailed interpretation of their 1H NMR spectra has been made. The structure of the bis(pyridylimino)isoindoline derivative has been determined by X-ray analysis to facilitate the assignment of the resonance lines in the NMR spectra. The complex is triclinic belonging to the space group P1 with a = 8.241(3), b = 12.274(4), c = 15.390(6) A, V = 1490.1(9) A3 and Dcalc = 1.66 g cm−3. The final R value was 0.058. The structure consists of a quadruply bonded dimolybdenum unit which is bound to three bridging acetates and one bridging BAII ligand. The BAII ligand is bound to one molybdenum by an imino nitrogen and to the other molybdenum by the isoindoline nitrogen and a pyridyl nitrogen. The pyridyl nitrogen is bound in a position approximately co-axial with the metal-metal bond. The MoMo bond distance is 2.109(1) A.
Enantiopure fluorine-containing taxoids: potent anticancer agents and versatile probes for biomedical problems

Abstract Fluorine-containing paclitaxel and docetaxel analogs are reported that are obtained through the coupling of enantiopure (3R,4S)-1-acyl-β-lactams with various baccatins. Some taxoids bearing the trifluoromethyl or difluoromethyl groups at the C-3′ position possessed three orders of magnitude greater potency than either paclitaxel or doxorubicin against both sensitive and drug-resistant human breast cancer cell lines. The incorporation of fluorine in taxoids as a probe has been successfully exploited for the study of their metabolism and structure. Fluorine-containing taxoids are shown to block the metabolic pathways associated with the cytochrome P-450 class of enzymes. Structural studies using 19 F and 1 H NMR techniques on fluorine-containing taxoids in combination with molecular modeling have provided new insights into the biologically relevant conformations of taxoids in solution as well as in the microtubule-bound state.
Upper bound on the capacity of Gaussian channels with noisy feedback

We consider an additive Gaussian channel with additive Gaussian noise feedback. We first derive an upper bound on the n-block capacity (defined by Cover [1]). It is shown that this upper bound can be obtained by solving a convex optimization problem. With stationarity assumptions on Gaussian noise processes, we characterize the limit of the n-block upper bound and prove that this limit is the upper bound of the noisy feedback (shannon) capacity.
Cutaneous manifestations of diabetes mellitus

Persons with diabetes mellitus comprise a sizable portion of the patient population. Chronic hyperglycemia, common to all types of diabetes mellitus, alters the small blood vessels and connective tissue of the skin in ways that can be clinically observed. Thickened and yellow skin, yellow nails, facial and periungual erythema are all common manifestations. Although these findings are currently only observations, perhaps they may eventually be useful markers of the patient’s past and present metabolic status.
Holography and condensed matter

This is a short review of recent developments in the application of AdS/CFT methods to some condensed matter problems. In particular we present the holographic description of a local quantum critical state, related to (non)-Fermi liquids and the strange metal, that appears in large N CFTs with a gravity dual at finite density and zero temperature, and explore its properties by probing it with fermionic operators. Further we discuss possible bosonic and fermionic instabilities, leading to s-, p- or d-wave holographic superconductors and “electron stars”. Finally we present a realization of local quantum criticality via an impurity problem.
Regulation of mammalian Notch signaling and embryonic development by the protein O-glucosyltransferase Rumi

Protein O-glucosylation is a conserved post-translational modification that occurs on epidermal growth factor-like (EGF) repeats harboring the C1-X-S-X-P-C2 consensus sequence. The Drosophila protein O-glucosyltransferase (Poglut) Rumi regulates Notch signaling, but the contribution of protein O-glucosylation to mammalian Notch signaling and embryonic development is not known. Here, we show that mouse Rumi encodes a Poglut, and that Rumi−/− mouse embryos die before embryonic day 9.5 with posterior axis truncation and severe defects in neural tube development, somitogenesis, cardiogenesis and vascular remodeling. Rumi knockdown in mouse cell lines results in cellular and molecular phenotypes of loss of Notch signaling without affecting Notch ligand binding. Biochemical, cell culture and cross-species transgenic experiments indicate that a decrease in Rumi levels results in reduced O-glucosylation of Notch EGF repeats, and that the enzymatic activity of Rumi is key to its regulatory role in the Notch pathway. Genetic interaction studies show that removing one copy of Rumi in a Jag1+/− (jagged 1) background results in severe bile duct morphogenesis defects. Altogether, our data indicate that addition of O-glucose to EGF repeats is essential for mouse embryonic development and Notch signaling, and that Jag1-induced signaling is sensitive to the gene dosage of the protein O-glucosyltransferase Rumi. Given that Rumi−/− embryos show more severe phenotypes compared to those displayed by other global regulators of canonical Notch signaling, Rumi is likely to have additional important targets during mammalian development.
Effective Passivation of Exfoliated Black Phosphorus Transistors against Ambient Degradation

Unencapsulated, exfoliated black phosphorus (BP) flakes are found to chemically degrade upon exposure to ambient conditions. Atomic force microscopy, electrostatic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy are employed to characterize the structure and chemistry of the degradation process, suggesting that O2 saturated H2O irreversibly reacts with BP to form oxidized phosphorus species. This interpretation is further supported by the observation that BP degradation occurs more rapidly on hydrophobic octadecyltrichlorosilane self-assembled monolayers and on H-Si(111) versus hydrophilic SiO2. For unencapsulated BP field-effect transistors, the ambient degradation causes large increases in threshold voltage after 6 h in ambient, followed by a ∼103 decrease in FET current on/off ratio and mobility after 48 h. Atomic layer deposited AlOx overlayers effectively suppress ambient degradation, allowing encapsulated BP FETs to ma...
Streakline flow visualization study of a horseshoe vortex in a large-scale, two-dimensional turbine stator cascade

Neutrally buoyant helium-filled bubbles were observed as they followed the streamlines in a horseshoe vortex system around the vane leading edge in a large-scale, two-dimensional, turbine stator cascade. Bubbles were introduced into the endwall boundary layer through a slot upstream of the vane leading edge. The paths of the bubbles were recorded photographically as streaklines on 16-mm movie film. Individual frames from the film have been selected, and overlayed to show the details of the horseshoe vortex around the leading edge. The transport of the vortex across the passage near the leading edge is clearly seen when compared to the streaks formed by bubbles carried in the main stream. Limiting streamlines on the endwall surface were traced by the flow of oil drops.
Behavior construction and refinement from high-level specifications

Mobile robots are excellent examples of systems that need to show a high level of autonomy. Often robots are loosely supervised by humans who are not intimately familiar with the inner workings of the robot. We cannot generally predict exact environmental conditions in which the robot will operate in advance. This means that the behavior must be adapted in the field. Untrained individuals cannot (and probably should not) program the robot to effect these changes. We need a system that will (a) allow re-tasking, and (b) allow adaptation of the behavior to the specific conditions in the field. In this paper we concentrate on (b). We will describe how to assemble controllers, based on high-level descriptions of the behavior. We will show how the behavior can be tuned by the human, despite not knowing how the code is put together. We will also show how this can be done automatically, using reinforcement learning, and point out the problems that must be overcome for this approach to work.
Structure and Dynamics of the Sun’s Open Magnetic Field

The solar magnetic field is the primary agent that drives solar activity and couples the Sun to the heliosphere. Although the details of this coupling depend on the quantitative properties of the field, many important aspects of the corona-solar wind connection can be understood by considering only the general topological properties of those regions on the Sun where the field extends from the photosphere out to interplanetary space, the so-called open field regions that are usually observed as coronal holes. From the simple assumptions that underlie the standard quasi-steady corona-wind theoretical models, and that are likely to hold for the Sun as well, we derive two conjectures as to the possible structure and dynamics of coronal holes: (1) coronal holes are unique in that every unipolar region on the photosphere can contain at most one coronal hole, and (2) coronal holes of nested polarity regions must themselves be nested. Magnetic reconnection plays the central role in enforcing these constraints on the field topology. From these conjectures we derive additional properties for the topology of open field regions, and propose several observational predictions for both the slowly varying and transient corona/solar wind.
A SPITZER SURVEY OF YOUNG STELLAR CLUSTERS WITHIN ONE KILOPARSEC OF THE SUN: CLUSTER CORE EXTRACTION AND BASIC STRUCTURAL ANALYSIS

We present a uniform mid-infrared imaging and photometric survey of 36 young, nearby, star-forming clusters and groups using Spitzer IRAC and MIPS. We have confidently identified and classified 2548 young stellar objects (YSOs) using recently established mid-infrared color-based methods. We have devised and applied a new algorithm for the isolation of local surface density enhancements from point source distributions, enabling us to extract the overdense cores of the observed star-forming regions for further analysis. We have compiled several basic structural measurements of these cluster cores from the data, such as mean surface densities of sources, cluster core radii, and aspect ratios, in order to characterize the ranges for these quantities. We find that a typical cluster core is 0.39 pc in radius, has 26 members with infrared excess in a ratio of Class II to Class I sources of 3.7, is embedded in a A{sub K} = 0.8 mag cloud clump, and has a surface density of 60 pc{sup -2}. We examine the nearest neighbor distances among the YSOs in several ways, demonstrating similarity in the spacings between Class II and Class I sources but large member clusters appear more dense than smaller clusters. We demonstrate that near-uniform source spacingsmore » in cluster cores are common, suggesting that simple Jeans fragmentation of parsec-scale cloud clumps may be the dominant process governing star formation in nearby clusters and groups. Finally, we compare our results to other similar surveys in the literature and discuss potential biases in the data to guide further interpretation.« less
Optimal Design and Governance of Asset-Backed Securities

Abstract A model of asymmetric asset value information and nonverifiability of liquidation motives is developed to examine the optimal design and governance of asset-backed securities. Because of adverse selection risk, the liquidation option of whole loan sale results in external price discounting of composite cash flows. The alternative liquidation option of senior/subordinated security design is shown to dominate whole loan sale, since cash flow splitting allows the issuer to internalize some or all of the lemons-related liquidation costs. Security subordination levels must increase relative to full information levels, however, to protect uninformed outside investors. Pool diversification and loan bundling are shown to be packaging strategies that can soften the lemons-related subordination effect and therefore increase liquidation proceeds. With respect to security governance, we show that it is the junior securityholder who should control the debt renegotiation process with pooled debt structures. Better asset value information and a first loss position are the reasons for junior securityholder control in our model. Numerous empirical implications of the model are also identified and discussed.Journal of Economic LiteratureClassification Numbers: D46, D81, D82, G13, G21, G24, G32, G33.
Doping dependence of the mobility enhancement in surface-channel strained-Si layers

In this paper we present simulation results for the doping dependence of the mobility enhancement in surface-channel strained-Si layers grown on relaxed Si1-xGex buffers. Our numerical results show that there is a significant reduction of the mobility enhancement with increasing substrate doping. At first, this result questioned the performance increase in devices based on these novel Si-based heteroepitaxy concepts when scaled to deep-submicron dimensions. However, we find that this is not really a problem since in devices with non-uniform doping profiles, representative of the state-of-the-art technology, significant mobility enhancement is still observed.
Boundary element analysis of a trapezoidal transmission line

A full-wave analysis is a transmission line with a trapezoidal cross-section is described. The boundary element method (BEM) is used, and by making a convenient choice for the dyadic Green's function, it is shown to be very efficient in comparison to alternative methods of analysis. It is shown that for electrically small dimensions, spurious solutions are suppressed by the selection of integral equations. The analysis is verified by comparisons to calculated results from a vector finite element computer program, and some dispersion data are presented. >