cssi/SciSciGPT-SciSciNet huggingface dataset:
Dental pulp stem cell responses to novel antibiotic‐containing scaffolds for regenerative endodontics

AbstractAimTo evaluate both the drug-release profile and the effects on human dental pulp stem cells' (hDPSC) proliferation and viability of novel bi-mix antibiotic-containing scaffolds intended for use as a drug delivery system for root canal disinfection prior to regenerative endodontics.Methodolo
The localizing value of a quadrantanopia.

Background: A lesion affecting the optic radiations may produce a quadrantanopia based on the topographical arrangement of the geniculocalcarine tract. Objective: To determine the localizing associations of a quadrantic visual field defect. Design: Retrospective study of case records of 41 patients with inferior quadrantanopia and 30 patients with superior quadrantanopia caused by disorders affecting the posterior visual pathway. The responsible lesion was identified with neuroimaging techniques. Setting: Neuro-ophthalmology referral practice in a large multispecialty clinic that provides primary, secondary, and tertiary medical care. Results: Cerebrovascular disorders accounted for most lesions. The location (and frequency) of lesions causing inferior quadrantanopia was occipital lobe (76%), parietal lobe (22%), and temporal lobe (2%). Other localizing signs were associated with 6%, 89%, and 0% of lesions located in the occipital, parietal, and temporal lobes, respectively. The location (and frequency) of lesions causing superior quadrantanopias was occipital lobe (83%), parietal lobe (3%), and temporal lobe (13%). Other localizing signs were associated with 4%, 100%, and 0% of lesions located in the occipital, parietal, and temporal lobes, respectively. Conclusions: A patient with a neurologically isolated quadrantanopia is likely to have a lesion in the occipital lobe, although, in the case of a superior quadrantanopia, the possibility of a temporal lobe lesion can not be excluded using clinical criteria only. Quadrantanopias caused by lesions of the parietal lobe usually are associated with other localizing signs.
Synthesis of bicyclic guanidines via cascade hydroamination/Michael additions of mono-N-acryloylpropargylguanidines.

A cascade silver(I)-catalyzed hydroamination/Michael addition sequence has been developed to deliver highly substituted bicyclic guanidines. This transformation gives rise to geometrically and constitutionally stable ene–guanidines and generates a remote stereocenter with moderate to high diastereoselectivity.
The interplay of invention, discovery, development, and application in organic synthetic methodology: A case study

This Perspective chronicles the conceptual development, proof of principle, exploration of scope, mechanistic investigations, and applications in natural product total synthesis of palladium-catalyzed cross-coupling reactions of silicon derivatives. The explication of how this new class of cross-coupling reactions evolved from problem formulation to use in complex molecule synthesis serves as one goal of the essay. The other goal is the presentation of the various stages of this methodological enterprise such that the reader gleans a first hand look at one approach to the creation of new synthetic reactions. These two goals are woven together such that the underlying thought processes that guide a program of reaction development emerge in clear view and imbue the chemical tapestry with a cohesive logic.
Unsteady evaporation and combustion of a drop cluster inside a vortex

A model has been developed that describes the evaporation, ignition, and combustion of a drop cluster embedded in a large vortex. The purpose of this model is to simulate the behavior of drops in large coherent vortices produced in the shear layer of a jet. The model treats the dynamic interactions between the drops and the vortex, and also takes into account the drop proximity to calculate the heat and mass transfer between drops and ambient gas. The gas phase outside the cluster is treated as an unsteady, reacting phase, whereas quasi-steadiness is assumed between the drops and surrounding gas inside the cluster. It is assumed that drops will not burn individually, but as a group. The results show a very complex interaction between the dynamics of the drop-loaded vortex, the flame, and the evaporation process. A quasi-steady state is not always reached, depending upon the drop number density or the vortex intensity. In most cases, the flame is located very close to the cluster. The mass ratio of burned fuel (at complete evaporation) to initial fuel is generally less than 10%.
Quantum dots in the strong confinement regime: a model system for gain in quasi zero-dimensional semiconductors

Abstract We present a model for gain in a quasi zero-dimensional quantum confined semiconductor system. Due to a combination of a multitude of one-electron-hole pair and two-electron-hole pair transitions and inhomogeneous broadening, the gain region is broad, quasi-continuous and stretches below the absorption edge. Femtosecond experiments in the gain region of strongly confined CdSe quantum dots confirm our theoretical predictions.
Single-Crystal-to-Single-Crystal Topochemical Polymerizations by Design

The polymerization of simple conjugated dienes has long been of interest: polydienes occur throughout Nature, and polyisoprene and its analogues form the basis of entire industries. In contrast, the polymers of similar small conjugated compounds, diacetylenes, trienes, and triacetylenes, are either unknown or laboratory curiosities. For 40 years, the only viable synthetic method for the 1,4-polymerization of a diacetylene was a topochemical polymerization in a condensed phase. But such an approach is hit or miss: if the diacetylene monomers have a solid-state structure preorganized at distances matching the repeat distance in the final polymer, then thermal or photochemical energy can bring about the polymerization. However, most monomers lack the proper structural parameters and simply do not react. As discussed in this Account, we have developed a supramolecular host−guest strategy that imposes the necessary structural parameters upon a diacetylene monomer that otherwise does not polymerize. We apply th...
Room-temperature Pd-catalyzed amidation of aryl bromides using tert-butyl carbamate.

The scope of Pd-catalyzed synthesis of N-Boc-protected anilines from aryl bromides and commercially available tert-butyl carbamate is described. For the first time, this process can be conducted at...
Role of synaptic feedback and intrinsic voltage-gated currents in shaping cone light responses

Abstract A model of the outer primate retina was used to investigate how cone light responses could be shaped by both synaptic feedback from horizontal cells and intrinsic voltage-gated conductances. Published data was used to estimate the photoconductance, convergence/divergence ratios, synaptic transfer functions, passive membrane properties and voltage-gated conductances, the latter using a Levenberg–Marquardt search algorithm. When the cone resting potential was sufficiently depolarized, synaptic feedback from horizontal cells could account for the flash response measured experimentally. Voltage-gated conductances were not significantly activated during the flash response but rather maintained the cone membrane potential inside a narrow physiological range.
JetSum: SMA actuator based undersea unmanned vehicle inspired by jellyfish bio-mechanics

Previously, we reported an undersea unmanned vehicle (UUV) termed as JetSum, inspired by the locomotion of medusa jellyfish, [12]. The propulsion of JetSum was based on shape memory alloy (SMA) wires replicating the contraction-relaxation cycle of natural jellyfish locomotion. In this paper, we report modified design of JetSum that addresses problems related to electrical isolation and power consumption. The modifications lead to significant improvement in functionality, providing implementation of a full continuous bell, bolstering critical sealing junctions, and reducing the overall power requirement. A LabVIEW controller program was developed to automate and optimize the driving of JetSum enabling reduction in power consumption for full contraction of SMA. JetSum locomotion in underwater conditions was recorded by using a high-speed camera and analyzed with image processing techniques developed in MatLab. The results show that JetSum was able to achieve velocity of 7 cm/s with power consumption of 8.94 W per cycle.
Proper Motions and Brightness Variations of Nonthermal X-Ray Filaments in the Cassiopeia a Supernova Remnant

We present Chandra ACIS X-ray observations of the Galactic supernova remnant Cassiopeia A taken in 2007 December. Combining these data with previous archival Chandra observations taken in 2000, 2002, and 2004, we estimate the remnant's forward shock velocity at various points around the outermost shell to range between 4200 and 5200 ± 500 km s–1. Using these results together with previous analyses of Cas A's X-ray emission, we present a model for the evolution of Cas A and find that it's expansion is well fit by a ρej ∝ r –(7–9) ejecta profile running into a circumstellar wind. We further find that while the position of the reverse shock in this model is consistent with that measured in the X-rays, in order to match the forward shock velocity and radius we had to assume that ~ 30% of the explosion energy has gone into accelerating cosmic rays at the forward shock. The new X-ray images also show that brightness variations can occur for some forward shock filaments like that seen for several nonthermal filaments seen projected in the interior of the remnant. Spectral fits to exterior forward shock filaments and interior nonthermal filaments show that they exhibit similar spectra. This together with similar flux variations suggests that interior nonthermal filaments might be simply forward shock filaments seen in projection and not located at the reverse shock as has been recently proposed.
Low-energy excitations, symmetry breaking and specific heat in YbBiPt

Abstract The heavy fermion compound YbBiPt has a very large linear coefficient of specific heat γ=8 J mol−1 K−2 and this is understood, to first order, in terms of the observed low-energy neutron scattering response. However, at low temperatures, symmetry forbidden splittings at 1 and 2 meV, respectively are observed. These levels give good qualitative agreement with the measured specific heat, but poor quantitative agreement. Indeed, the specific heat drops more rapidly with temperature than can be accounted for assuming a temperature-independent density of states. We also present new low-temperature crystallographic data, which rule out any significant structural distortions.
A method of object-oriented information management for layout design

During the layout design process, the spatial arrangement of components in an engineering system is developed in order to meet design goals and constraints. Proper organization of the information involved in this process enhances the quality of layout designs. The organization of information is accomplished through the use of the techniques and methods existing in the information management field. Using the object-oriented technique, a method was developed to guide the design of information management systems that support the layout design process. The method was developed in a case study involving, the layout design of automobile engine bay compoenents.
False Consensus Goes Online Impact of Ideologically Homogeneous Groups on False Consensus

This study analyzes survey data obtained from members of neo-Nazi and radical environmentalist discussion forums. It assesses the extent to which participants in homogeneous online groups exhibit false consensus, i.e., overestimate public support for their views, and whether the overestimation increases with increased online participation. Although the analyzed sample overestimates public support, the overestimation is no greater than found with more conventional populations studied to date. However, false consensus among the neo-Nazis increases with their involvement in online groups, also controlling for extremism. Among the environmentalists, it is the extremism, not online participation that accounts for false consensus. Theoretical and practical implications of these findings are discussed.
An Automated Algorithm to Distinguish and Characterize Solar Flares and Associated Sequential Chromospheric Brightenings

We present a new automated algorithm to identify, track, and characterize small-scale brightening associated with solar eruptive phenomena observed in Hα. The temporal, spatially localized changes in chromospheric intensities can be separated into two categories: flare ribbons and sequential chromospheric brightenings (SCBs). Within each category of brightening we determine the smallest resolvable locus of pixels, a kernel, and track the temporal evolution of the position and intensity of each kernel. This tracking is accomplished by isolating the eruptive features, identifying kernels, and linking detections between frames into trajectories of kernels. We fully characterize the evolving intensity and morphology of the flare ribbons by observing the tracked flare kernels in aggregate. With the location of SCB and flare kernels identified, they can easily be overlaid on complementary data sets to extract Doppler velocities and magnetic-field intensities underlying the kernels. This algorithm is adaptable to any dataset to identify and track solar features.
Propylene oxide production from propylene by immobilized whole cells of Methylosinus sp. CRL 31 in a gas-solid bioreactor

Methanotrophic bacteria have been shown to oxidize gaseous alkenes to the corresponding epoxides utilizing an NADH2-dependent methane monooxygenase. A cell paste of methane-grown methylotrophs was coated on porous glass beads. The production of propylene oxide from propylene was performed in a gas-solid bioreactor to ensure continuous production and removal of product epoxide from the microenvironment of the biocatalyst. The amount of propylene oxide produced before cofactor regeneration was between 120–145 μmoles/20 mg cells in about 10 h depending on the microbial strains used. The conversion rate for propylene was 2.7%. Regeneration of cofactor NADH2 was performed in the bioreactor with the vapor of a cosubstrate, methanol.
Motorized two-point safety belt effectiveness in preventing fatalities

The effectiveness of two-point motorized restraint systems in preventing fatalities to outboard front-seat car occupants is estimated using published fatality data for one model car equipped with a motorized two-point-belt system, together with a number of assumptions. Effectiveness estimates are obtained for the motorized belt system as used in the field, which reflects the mix of occupants who do and do not fasten the manual lap belt, and for effectiveness when the lap belt is not used. This latter estimate is, therefore, an estimate of the effectiveness of shoulder belts in preventing fatalities. In the data for the one car model, 18% of the fatally injured occupants were ejected. By assuming that three-point belt systems prevent ejection, these data are used to compute the difference in effectiveness between two-point and three-point systems. The result applies to the two-point belt system used in conjunction with whatever manual belt-use rates occurred in traffic. From published observations of lap-belt-use rates for this same vehicle, the effectiveness of the shoulder belt only is estimated. It is found that effectiveness of the two-point restraint system in conjunction with the lap-belt use that occurred in traffic is (32 +/- 5)%. The effectiveness of the shoulder belt only is estimated as (29 +/- 8)%.
A case of collusion: a study of the interface between ad libraries and their apps

A growing concern with advertisement libraries on Android is their ability to exfiltrate personal information from their host applications. While previous work has looked at the libraries' abilities to extract private information from the system, advertising libraries also include APIs through which a host application can deliberately leak private information about the user. This study, considering a corpus of 114,000 apps, is the first to focus on those APIs. We reconstruct the APIs for 103 ad libraries used in the corpus, and study how the privacy leaking APIs from the top 20 ad libraries are used by the 64,000 applications in which they are included. Notably, we have found that app popularity correlates with privacy leakage; the marginal increase in advertising revenue, multiplied over a larger user base, seems to incentivize these app vendors to violate their users' privacy.
EXTRACTING THE DARK MATTER PROFILE OF A RELAXED GALAXY CLUSTER

Knowledge of the structure of galaxy clusters is essential for an understanding of large-scale structure in the universe and may provide important clues to the nature of dark matter. Moreover, the shape of the dark matter distribution in the cluster core may offer insight into the structure formation process. Unfortunately, cluster cores also tend to be the site of complicated astrophysics. X-ray imaging spectroscopy of relaxed clusters, a standard technique for mapping their dark matter distributions, is often complicated by the presence of cool components in cluster cores, and the dark matter profile one derives for a cluster is sensitive to assumptions made about the distribution of this component. In addition, fluctuations in the temperature measurements resulting from normal statistical variance can produce results that are unphysical. We present here a procedure for extracting the dark matter profile of a spherically symmetric, relaxed galaxy cluster that deals with both of these complications. We apply this technique to a sample of galaxy clusters observed with the Chandra X-Ray Observatory and comment on the resulting mass profiles. For some of the clusters we compare their masses with those derived from weak and strong gravitational measurements.
Characteristics of 2–6 MeV electrons in the slot region and inner radiation belt

[1] In this paper, the long-term relativistic electron behavior in the often overlooked “slot” region and the inner belt was studied using the 2–6 MeV electron data from the SAMPEX satellite during 1992–2004. In particular, we investigated the penetration of the 2–6 MeV electrons to the slot region, their flux enhancement in the inner belt, and how these two processes are related to magnetospheric activity levels and solar wind parameters. It is found that the 2–6 MeV electron penetration (L 550 km s−1) as well as low solar wind density (∼4.4 cm−3). Either a couple of very extreme storms or recurrent intense storms will create conditions favorable for the MeV electron enhancement in the inner belt. However, without high-speed solar wind on average, a series of intense storms alone are not sufficient to create inner belt electron flux enhancement.
Formation of the terrestrial planets

The early phases of formation in the inner solar system were dominated by collisions and short-range dynamical interactions among planetesimals. But the later phases, which account for most of the differences among planets, are unsure because the dynamics are more subtle. Jupiter’s influence became more important, leading to drastic clearing out of the asteroid belt and the stunting of Mars’s growth. Further in, the effect of Jupiter— both directly and indirectly, through ejection of mass in the outer solar system— was probably to speed up the process without greatly affecting the outcome. The great variety in bulk properties of the terrestrial bodies indicate a terminal phase of great collisions, so that the outcome is the result of small-N statistics. Mercury, 65 percent iron, appears to be a residual core from a high-velocity collision. All planets appear to require a late phase of high energy impacts to erode their atmospheres: including the Earth, to remove CO2 so that its ocean could form by condensation of water.
Dopants and defects in InN and InGaN alloys

We have performed systematic studies of the effects of high-energy particle irradiation on the properties of InGaN alloys. In agreement with the amphoteric defect model, irradiation of InN produces donor-like defects. The electron concentration increases with increasing radiation dose and saturates at 4 x 10 20 cm -3 at very high doses. We find that the increase of the electron concentration causes a large blue-shift of the absorption edge, which is well explained by the Burstein-Moss effect. The maximum electron concentration decreases with increasing Ga fraction in irradiated In 1-x Ga x N alloys as the conduction band edge approaches the Fermi level stabilization energy (E FS ). For x>0.66 the conduction band edge moves above E FS and the irradiation of n-type films produces acceptor-like defects, resulting in a reduced free electron concentration. An analysis of the concentration dependence of the electron mobility in InN indicates that the dominant defects in irradiated InN are triply charged donors. Finally, we show that InN films doped with Mg acceptors behave like undoped films above a threshold radiation dose.
Chemical stress cracking of acrylic fibres

The generation of periodic microscopic transverse cracks in oriented acrylic fibres immersed in hot alkaline hypochlorite solution is described in detail and shown to be a variety of chemical stress cracking. It is greatly accelerated by external tensile stress, high fibre permeability, moderate fibre orientation, and water-plasticization. The proposed mechanism for bond cleavage involves cyclization of nitrile groups (similar to the “prefatory reaction” in pyrolysis of acrylic fibres), followed immediately by N-chlorination and chain scission. Mechanical retractile forces (internal or external) then cause chain retraction and crack growth. Despite the remarkable regularity of the crack pattern, which typically resembles a series of stacked lamellae, the process is independent of any such underlying fibre morphology. The cracking process does, however, appear to be a sensitive indicator of residual latent strain in the fibre, which may persist even after high-temperature annealing.
The structure of hexaaquanickel(II) chlorate

Hexaaquanickel(II) chlorate, [Ni(H2O)6]-(ClO3)2, Mr = 333.69, cubic, Pa3-, a = 10.3159 (5) A, V = 1097.80 (5) A3, Z = 4, F(000) = 680, Dx = 2.02 g cm-3, lambda(Mo K alpha-) = 0.71069 A, T = 296 K, mu = 23.13 cm-1, R = 0.026 for 388 unique reflections having I greater than sigma I. The single type of Ni ion is coordinated by six water-molecule O atoms, each at an observed distance 2.054 (1) A, in an almost regular octahedral array. The single type of chlorate ion has a Cl--O bond length 1.487 (1) A and O--Cl--O bond angle 106.45 (6) degrees. The Ni--O complex, but not the chlorate ion, manifested rigid-body behavior. The Ni--O distance corrected for rigid-body motion is 2.060 A. Location and refinement of the two inequivalent H atoms permitted a detailed analysis of hydrogen bonding, which occurs principally between the oxygen octahedra and the chlorate groups.
Erectile dysfunction and cardiovascular risk factors

Erectile dysfunction (ED), the consistent inability of a man to achieve an erection satisfactory for sexual activity, has been estimated to afflict, to some degree, 52% of male adults between the ages of 40 and 70 yr in the United States (1).Millions of men in the United States suffer with ED. Although there are numerous causes of ED (vascular, psychogenic, neurologic, endocrine, structural, traumatic, and drug-related) in men over age 50 yr, the most common cause is thought to be vascular (2–4). This chapter reviews the connection between ED and vascular disease and the connection between ED and risk factors for atherosclerosis.
Simplified method of rotating skin and mucous membrane flaps for complete reconstruction of the lower lip

D EFECTS of the lower lip result from inflammatory or degenerative processes, as advanced carcinoma’, 2 and extensive ulcerations (noma) ; or traumatisms from burnss or other accidents.4g 5 That’ reconstruction of these defects has been a surgical problem for many years is evidenced by the fact that according to Pierce and O’Conno~,~ over sixty-five methods and modifications of repairing complete or partial defects of the lower lip have been described in the literature. According to Martin6 von Bruns,7 as early as 1859, had found thirty-two methods described by fifty-two authors. That there have been so many different methods for the correction of this defect is indicative of the inexpedience of any one method. This fact should decry, on the one hand, the advancement of a new technique which may be only as good as others previously advocated, and yet, on the other hand, should be a stimulant to the development of a technique which fulfills satisfactorily all surgical requirements. Cheiloplasty for carcinoma of the lower lip, one of the oldest operations known, has been practiced since the days of Celsus (born about A.D. 25).B He is generally considered the originator of a method, the principle of which is still adhered to today-V-shaped incision and modifications including horizontal incisions from the angles of the mouth and along the lower edge of the mandible forming two lateral flaps of the cheek. Sccording to Fornan,’ the Hindus utilized rotating flaps from the adjacent tissues to rebuild a defect of the lip; this later became known as the lndian method. Tagliacozzi is accredited with the first description of a technique using flaps from the arm (1597).9 Chopart,‘o in 1785, reported the use of advancing flaps from the neck and chin for this purpose. Most of the operations advocated today are modifications of procedures, the basic principles of which were recognized in the early nineteenth century. BernardI and Burow and Saemann,l* in 1853, devised an operation in which full-thickness triangles were removed from the upper lip and discarded. The lower lip was then built by loosenin g and pulling the sides of the cheeks to the midline over the mandible. This procedure was modified by Steward,‘” in 1910, and Martin6 in 1932. In 1877, Estlander14 proposed a procedure which is one of the recognized methods of lip reconstruction today. A V-shaped incision is made. A similar defect only one-half the size is outlined at the outer border of the corresponding upper lip and excised completely, excepting the tissue where the coronary artery of the lip is located. The upper triangle is then turned down into the lower lip and sutured. In 1936, Padgett15 modified this operation by bringing
Synthesis of Δ1-1,2-Diazetines via a Diels−Alder Cycloaddition Approach

A novel method for the synthesis of Δ1-1,2-diazetines is presented. Diels−Alder cycloaddition of dienophile 4 with five dienes afforded cycloadducts in good to excellent yields. Four of the obtained cycloadducts were converted to the corresponding diazetines.
Towards a Communication-Theoretic Understanding of System-Level Power Consumption

Traditional communication theory focuses on minimizing transmit power. However, communication links are increasingly operating at shorter ranges where transmit power can be significantly smaller than the power consumed in decoding. This paper models the required decoding power and investigates the minimization of total system power from two complementary perspectives. First, an isolated point-to-point link is considered. Using new lower bounds on the complexity of message-passing decoding, lower bounds are derived on decoding power. These bounds show that 1) there is a fundamental tradeoff between transmit and decoding power; 2) unlike the implications of the traditional "waterfall" curve which focuses on transmit power, the total power must diverge to infinity as error probability goes to zero; 3) Regular LDPCs, and not their known capacity-achieving irregular counterparts, can be shown to be power order optimal in some cases; and 4) the optimizing transmit power is bounded away from the Shannon limit. Second, we consider a collection of links. When systems both generate and face interference, coding allows a system to support a higher density of transmitter-receiver pairs (assuming interference is treated as noise). However, at low densities, uncoded transmission may be more power-efficient in some cases.
Tidal Disruption of Protoclusters in Giant Molecular Clouds

We study the collapse of protoclusters within a giant molecular cloud (GMC) to determine the conditions under which collapse is significantly disrupted. Motivated by observations of star-forming regions which exhibit flattened cloud structures, this study considers collapsing protoclusters with disk geometries. The collapse of a 103 M☉ protocluster initially a distance of 2-10 pc from a 103-106 M☉ point mass is numerically calculated. Simulations with zero initial relative velocity between the two are completed, as well as simulations with relative velocities consistent with those observed in GMCs. The results allow us to define the conditions under which it is safe to assume that protocluster collapse proceeds as if in isolation. For instance, we find that the collapse of a 103 M☉ protocluster will be significantly disrupted if it is within 2-4 pc of a 104 M☉ point mass. Thus, the collapse of a 103 M☉ protocluster can be considered to proceed as if in isolation if it is more than ~4 pc away from a 104 M☉ compact object. In addition, in no portion of the sampled parameter space does the gravitational interaction between the protocluster disk and the massive particle significantly disperse the disk into the background GMC. We discuss the distribution of clusters of young stellar objects within the Perseus and Mon R2 star-forming regions, which are consistent with the results of our simulations and the limitations of our results in gas dominated regions such as the Orion cloud.
Private Analysis of Graph Structure

We present efficient algorithms for releasing useful statistics about graph data while providing rigorous privacy guarantees. Our algorithms work on datasets that consist of relationships between individuals, such as social ties or email communication. The algorithms satisfy edge differential privacy, which essentially requires that the presence or absence of any particular relationship be hidden.Our algorithms output approximate answers to subgraph counting queries. Given a query graph H, for example, a triangle, k-star, or k-triangle, the goal is to return the number of edge-induced isomorphic copies of H in the input graph. The special case of triangles was considered by Nissim et al. [2007] and a more general investigation of arbitrary query graphs was initiated by Rastogi et al. [2009]. We extend the approach of Nissim et al. to a new class of statistics, namely k-star queries. We also give algorithms for k-triangle queries using a different approach based on the higher-order local sensitivity. For the specific graph statistics we consider (i.e., k-stars and k-triangles), we significantly improve on the work of Rastogi et al.: our algorithms satisfy a stronger notion of privacy that does not rely on the adversary having a particular prior distribution on the data, and add less noise to the answers before releasing them.We evaluate the accuracy of our algorithms both theoretically and empirically, using a variety of real and synthetic datasets. We give explicit, simple conditions under which these algorithms add a small amount of noise. We also provide the average-case analysis in the Erdos-Renyi-Gilbert G(n,p) random graph model.Finally, we give hardness results indicating that the approach Nissim et al. used for triangles cannot easily be extended to k-triangles (hence justifying our development of a new algorithmic approach).
Macrocyclic Cyclopropenes by Highly Enantioselective Intramolecular Addition of Metal Carbenes to Alkynes.

The intramolecular addition of a diazo ester group to a triple bond in the presence of chiral dirhodium(II) carboxamidate catalysts gives macrocyclic lactones with a fused cycloproprene ring [Eq. (a)]. This efficient reaction is characterized by high enantiocontrol (up to 98% ee) and chemoselectivity.
Bioresponsive, cell-penetrating, and multimeric MR contrast agents.

Magnetic resonance imaging (MRI) has become increasingly popular in experimental molecular imaging and clinical radiology because it is non-invasive and capable of producing three-dimensional representations of opaque organisms with high spatial and temporal resolution. Approximately 35% of all clinical MR scans utilize contrast media, however a primary limitation of MR imaging is the sensitivity of contrast agents that require high concentrations (0.1−0.6 mM).(1) A number of strategies have been employed to amplify the observed in vivo signal of MR contrast agents. Approaches include attachment of Gd(III) chelates to polymers, proteins and particles, encapsulation into micelles and caged structures, and targeting to receptors. While each of these approaches has yielded significant increases in the relaxivity of MR contrast agents (and therefore sensitivity), all of these classes of complexes possess intrinsic background signal and function solely as anatomical reporters. In order to reduce the background...
Sharp quadratic majorization in one dimension

Majorization methods solve minimization problems by replacing a complicated problem by a sequence of simpler problems. Solving the sequence of simple optimization problems guarantees convergence to a solution of the complicated original problem. Convergence is guaranteed by requiring that the approximating functions majorize the original function at the current solution. The leading examples of majorization are the EM algorithm and the SMACOF algorithm used in Multidimensional Scaling. The simplest possible majorizing subproblems are quadratic, because minimizing a quadratic is easy to do. In this paper quadratic majorizations for real-valued functions of a real variable are analyzed, and the concept of sharp majorization is introduced and studied. Applications to logit, probit, and robust loss functions are discussed.
Polarizing the Nazarov Cyclization: Efficient Catalysis under Mild Conditions

Substituted divinyl ketones were studied in the Nazarov cyclization. α-Carbomethoxy divinyl ketones underwent efficient Nazarov cyclization with catalytic copper triflate (2 mol %) to give a single cyclopentenone regio- and stereoisomer. The efficiency of the cyclizations correlated with the ability of the substituents to favorably polarize the π-system of the cationic intermediate.
Density and level set-XFEM schemes for topology optimization of 3-D structures

As the capabilities of additive manufacturing techniques increase, topology optimization provides a promising approach to design geometrically sophisticated structures. Traditional topology optimization methods aim at finding conceptual designs, but they often do not resolve sufficiently the geometry and the structural response such that the optimized designs can be directly used for manufacturing. To overcome these limitations, this paper studies the viability of the extended finite element method (XFEM) in combination with the level-set method (LSM) for topology optimization of three dimensional structures. The LSM describes the geometry by defining the nodal level set values via explicit functions of the optimization variables. The structural response is predicted by a generalized version of the XFEM. The LSM–XFEM approach is compared against results from a traditional Solid Isotropic Material with Penalization method for two-phase "solid–void" and "solid–solid" problems. The numerical results demonstrate that the LSM–XFEM approach describes crisply the geometry and predicts the structural response with acceptable accuracy even on coarse meshes.
The ABCDEF’s of matrix models for supersymmetric Chern-Simons theories

We consider $ \mathcal{N} = {3} $ supersymmetric Chern-Simons gauge theories with product unitary and orthosymplectic groups and bifundamental and fundamental fields. We study the partition functions on an S 3 by using the Kapustin-Willett-Yaakov matrix model. The saddlepoint equations in a large N limit lead to a constraint that the long range forces between the eigenvalues must cancel; the resulting quiver theories are of affine Dynkin type. We introduce a folding/unfolding trick which lets us, at the level of the large N matrix model, (i) map quivers with orthosymplectic groups to those with unitary groups, and (ii) obtain non-simply laced quivers from the corresponding simply laced quivers using a $ {{\mathbb{Z}}_{{2}}} $ outer automorphism. The brane configurations of the quivers are described in string theory and the folding/unfolding is interpreted as the addition/subtraction of orientifold and orbifold planes. We also relate the U(N) quiver theories to the affine ADE quiver matrix models with a Stieltjes-Wigert type potential, and derive the generalized Seiberg duality in 2 + 1 dimensions from Seiberg duality in 3 + 1 dimensions.
Incorporating edge information into best merge region-growing segmentation

We have previously developed a best merge region-growing approach that integrates nonadjacent region object aggregation with the neighboring region merge process usually employed in region growing segmentation approaches. This approach has been named HSeg, because it provides a hierarchical set of image segmentation results. Up to this point, HSeg considered only global region feature information in the region growing decision process. We present here three new versions of HSeg that include local edge information into the region growing decision process at different levels of rigor. We then compare the effectiveness and processing times of these new versions HSeg with each other and with the original version of HSeg.
Synthesis of 4-[(1,3-diaminopyrrolo[3′,4′:4,5]pyrido[2,3-d]-pyrimidin-8-yl)benzoyl]-L-glutamic acid as a potential antifolate

This paper is dedicated to the memory of Professor Roland K. Robins The synthesis of 4-[(1,3-diaminopyrrolo[3′,4′:4,5]pyrido[2,3-d]pyrimidin-8-yl)benzoyl]-L-glutamic acid (18), a potential antifolate and anticancer agent, has been achieved starting from 1,4-dibromobutan-2-ol with alkyl p-aminobenzoic acids. Condensation of these two agents gave 1-(4-alkoxycarbonylphenyl)pyrrolidin-3-ols 7a,b, which were oxidized to the corresponding pyrrolidin-3-one derivatives 8a,b. Compounds 8a,b were converted into 1,3-diamino-8-(4-alkoxycarbonylphenyl)-7,8-dihydro-9H-pyrrolo[3′,4′:4,5]pyrido[2,3-d]pyrimidines 12a,b in 4 steps. Saponification of 12b the benzoate ester and coupling with di-tert-butyl glutamate afforded a mixture of 7,8-dihydro product 16 and its aromatized derivative 17. Finally hydrolysis of esters 16 or 17 gave only the title compound 18. The 7,8-dihydro tricyclic derivatives were easily air-oxidized to form their fully aromatized compounds. The title compound 18 was one tenth less active than MTX against HL-60 cells in culture.
Observations of Planetary Nebulae at Radio Wavelengths

Planetary nebulae are weak radio sources. The radio emission of planetary nebulae is primarily due to free-free transitions in the ionized hydrogen cloud. Very large radio telescopes and sensitive receivers are needed to detect the weak radio emission of planetary nebulae. During the last 3 years about 80 planetary nebulae have been detected at some one radio frequency, and more than 60% of these have been detected at more than one frequency. Most of the measurements have been made to measure the flux densities of the nebulae and determine their radio spectra. A few interfero­metric observations have also been made to determine the radio widths of planetary nebulae. In some cases the radio observations have been used to determine the electron temperatures and emission measures of planetary nebulae, and also to derive the interstellar extinction at Hβ.
Microsurgical Anatomy of Acoustic Neuroma

This article reviews the microsurgical anatomy important to preserving the involved cranial nerves and adjacent neural and vascular structures during acoustic neuroma removal. These anatomic considerations are divided into sections dealing with the relationships at the lateral end of the tumor in the meatus and those on the medial end of the tumor at the brain stem. The anatomy of the region offers the opportunity for three approaches to the tumor in the meatus and cerebellopontine angle. One is directed through the middle cranial fossa and the roof of the meatus. Another is directed throught the labyrinth and posterior surface of the temporal bone. The third is directed through the posterior cranial fossa and posterior meatel lip. The anatomy presented by all three approaches is reviewed in this article.
The Persistence of Income Shocks: Evidence from Rural Indonesia

This paper estimates the persistence of transient income shocks to farm households in rural Indonesia. Persistence is defined as the elasticity of a household's 1997 household per capita income with respect to its 1993 per capita income, controlling for time-invariant characteristics of the household. Local rainfall levels are used as an exogenous source of transitory variation in 1993 income. Four main conclusions emerge. First, roughly 30% of household income shocks remain after four years. Second, the persistence of negative and positive shocks is approximately equal; if anything, positive shocks last longer. Third, neither positive nor negative income shocks disproportionately affect poor households. Finally, measurement error in income and unobserved household heterogeneity are important sources of bias. These findings cast doubt on common arguments advocating public intervention to stabilize or redistribute income, and suggest that anti-poverty policy should address more permanent causes of household poverty.
On the nature of high-temperature superconductivity

A picture of the electronic structure, magnetism, and superconductivity in high-T/sub c/ oxides is obtained from a simple analysis of experiments and models of the copper oxide planes. It is shown that magnetism is associated with holes on copper and superconductivity with holes on oxygen. The pairing force is not retarded. Questions about the motion of charges in an antiferromagnetic background and the many-body theory of high-temperature superconductivity are discussed. Differences between the cuprates and doped BaBiO/sub 3/ are emphasized.
Shelling Coxeter-like complexes and sorting on trees

Abstract In their work on ‘Coxeter-like complexes’, Babson and Reiner introduced a simplicial complex Δ T associated to each tree T on n nodes, generalizing chessboard complexes and type A Coxeter complexes. They conjectured that Δ T is ( n − b − 1 ) -connected when the tree has b leaves. We provide a shelling for the ( n − b ) -skeleton of Δ T , thereby proving this conjecture. In the process, we introduce notions of weak order and inversion functions on the labellings of a tree T which imply shellability of Δ T , and we construct such inversion functions for a large enough class of trees to deduce the aforementioned conjecture and also recover the shellability of chessboard complexes M m , n with n ⩾ 2 m − 1 . We also prove that the existence or nonexistence of an inversion function for a fixed tree governs which networks with a tree structure admit greedy sorting algorithms by inversion elimination and provide an inversion function for trees where each vertex has capacity at least its degree minus one.
The New Keynesian Phillips Curve and the cyclicality of marginal cost

Abstract Several authors argue that if the labor income share is used as the proxy for real marginal cost, then the New Keynesian Phillips Curve does a good job of approximating US inflation dynamics. However, this paper argues that the labor share is not an ideal measure of real marginal cost for two reasons: it is countercyclical whereas marginal cost is likely to be procyclical, and it assumes that labor can be costlessly adjusted at a fixed real wage rate. Relaxing this assumption to a more realistic one leads to a measure of marginal cost that does turn out to be procyclical, which when tested produces results that are contradictory to the entire underlying model of the NKPC. Indeed, this paper argues that having procyclical marginal cost precludes us from even having the correct coefficient signs in the NKPC, which highlights a major problem that exists in the model.
The Imprint of Dark Energy

Diverse cosmological observations indicate the existence of dark energy, comprising ~ 70% of the total cosmic energy density and driving the accelerated cosmic expansion. Possible explanations for the dark energy include a cosmological constant and quintessence — a time-varying, inhomogeneous field with negative pressure. In this article we summarize how the dark energy imprints features on the cosmic microwave background. Observation of these features could be useful in discriminating amongst various theories, and could reveal clues as to the nature of the dark energy.
Automation Techniques for Thermal Analysis of Spacecraft Systems

The evaluation of the design and performance of current and future hypersonic flight vehicles, including the Shuttle Orbiter, National Aerospace Plane (NASP), and assured crew return vehicle (ACRV), requires rigorous and very extensive thermal analyses. These analyses are imperative to ensure that the design of spacecraft systems is adequate and that safety margins are proper for given mission requirements. Conventionally, thermal analyses have been performed manually, that is, without the aid of integrated automatic procedures for constructing nodalized thermal models, incorporating initial and boundary conditions, and performing other necessary modifications. These manual processes require considerable manpower that could be utilized for other tasks. In order to improve these time-consuming and tedious analysis procedures, an engineering concept and methodology for automating thermal analysis has been developed and implemented for the thermal analysis of the Space Shuttle Orbiter. This paper discusses this new methodology.
Gamma-ray burst prompt emission: Implications from shock acceleration theory

Abstract The principal paradigm for gamma-ray bursts (GRB) suggest that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper illustrates some properties of diffusive acceleration at relativistic shocks that pertain to GRB models, providing interpretation of the BATSE/EGRET data. Using a standard Monte Carlo simulation, computations of the spectral shape, and the range of spectral indices are presented, as functions of the shock speed, magnetic field obliquity and the type of particle scattering. It is clear that while quasi-parallel, relativistic shocks with fields approximately normal to the shock plane can efficiently accelerate particles, highly oblique and perpendicular ones cannot unless the particle diffusion is almost isotropic, i.e., extremely close to the Bohm limit. Accordingly, an array of distribution indices should be present in the burst population, as is exhibited by the EGRET data, and even mildly relativistic internal shocks require strong field turbulence in order to model the >100 MeV observations. In addition, recent spectral fitting to burst data in the BATSE band is discussed, providing probes of the efficiency of injection of non-thermal electrons.
Correlation and Prediction of the Refractive Indices of Polymers by QSPR

A general QSPR model (R2 = 0.940, s = 0.018) was developed for the prediction of the refractive index for a diverse set of amorphous homopolymers with the CODESSA program. The five descriptors, involved in the model, are calculated from the structure of the repeating unit of the polymer. The average prediction error by this model is 0.9%.
Radiation Damage in Semiconductor Detectors

A survey is presented of the important damage-producing interactions in semiconductor detectors and estimates of defect numbers are made for MeV protons, neutrons and electrons. Damage effects of fast neutrons in germanium gamma ray spectrometers are given in some detail. General effects in silicon detectors are discussed and damage constants and their relationship to leakage current is introduced.