cssi/SciSciGPT-SciSciNet huggingface dataset:
Sequence of centromere separation another mechanism for the origin of nondisjunction

The most commonly accepted view about the origin of aneuploidy is that it is due to errors in meiotic division. However, its rare occurrence makes it difficult to explain recurrent births of trisomic children to some parents. This problem causes more serious concern when one accepts that an abnormal (n + 1 or n - 1) sperm would enter fertilization by overriding thousands, or even millions, of normal haploid sperms. Also, the failure of aneuploidy to be induced in the offspring of mammals treated with mutagens raises questions about the effectiveness of the accepted mode of origin of errors. Current concepts also do not explain why one observes more errors of meiotic I, than of meiotic II, origin. It is known that most chromosomes separating at meta-anaphase junction in mitosis follow a nonrandom, genetically controlled sequence of separation. The present proposal makes use of out-of-phase separation of a rare chromosome, like premature separation in mitosis of the X in elderly humans or of an 18 in parents of trisomy 18 children. The suggestion is made that such out-of-phase separation results in aneuploid cell lines by total failure of the centromere to separate or by it separating too early, before the spindle is formed. The prematurely separating centromeres, it appears, do not attach to spindle fibers and hence cause nondisjunction. Such nondisjunction in embryonic stages will produce apparently normal individuals with mosaicism in somatic and/or gametic tissue. An individual carrying mosaicism in gonadal tissue will produce a large number of abnormal gametes, one of which may have a reasonable chance of entering fertilization. This mode of origin of aneuploidy takes care of all questions raised above and finds support in the data available in the literature. Several of the suggestions made in the hypothesis are easily testable.
A property of local cohomology modules of polynomial rings

Let R = k[x 1 ,···, x n ] be a polynomial ring over a field k of characteristic p > 0, and let I = (f 1 ,···, f s ) be an ideal of R. We prove that every associated prime P of H i I (R) satisfies dimR/P ≥ n - ∑ deg f i . In characteristic 0 the question is open.
Loyalty-Based Portfolio Choice

I evaluate the effect of loyalty on individuals' portfolio choice using a unique dataset of retirement contributions. I exploit the statutory difference that, in 401(k) plans, stand-alone employees can invest directly in their division, while conglomerate employees must invest in the entire firm, including all unrelated divisions. Consistent with loyalty, employees of stand-alone firms invest 10 percentage points (75%) more in company stock than conglomerate employees. Support is also found using variation in loyalty between different groups of employees, across and within firms. The cost to employees of loyalty is large, amounting to nearly a 20% loss in retirement income.
Favorable Leukemia-Free Survival (LFS) for Adults and Children Undergoing Myeloablative Umbilical Cord Blood (UCB) Transplantation with Cyclophosphamide (CY), Fludarabine (FLU) and Total Body Irradiation (TBI): A Single Center Analysis of 194 Patients

We evaluated the outcomes in 194 consecutive patients (pts) transplanted with UCB after a myeloablative therapy for acute myeloid leukemia (AML,n=86), acute lymphoblastic leukemia (ALL,n=89), chronic myeloid leukemia (CML,n=13), and myelodysplastic syndrome (MDS,n=6) between 1995 and 2007. Methods: Pts were assigned to 3 treatment groups (Table 1): Cy 120mg/kg, TBI 1320 cGy and equine anti-thymocyte globulin (ATG) 90mg/kg with one UCB unit (CyTBI, 1995–2000; n=65; median age 9 yrs, r 0.5–52); CyTBI and Flu 75mg/m2/day with one UCB unit (CYFluTBI-1, 2000–2007; n=36; median age 8yrs, r 2–44); and Cy/Flu/TBI with two UCB units (CyFluTBI-2, 2001–2007; n=93; median age 25yrs, r 9–45). All received cyclosporine A (CsA) with either short course methylprednisolone (2 mg/kg/days; days +5 to +19) or mycophenolate mofetil (days -3 to +30). Pts were classified as standard (acute leukemia in CR1-2 or CML in first chronic phase, n=138) or high risk (n=56) for relapse. Median follow-up for survivors is 2.8 years (r: 0.7–9.2). Pts received a 0–1 HLA-mismatched graft in 81% for CyFluTBI-1, 47% for CyTBI, and 36% for CyFluTBI-2 (p<.01). The total nucleated cell dose infused in recipients of CyFluTBI-1 was 3.6 (2.1–13.9), CyTBI 3.0 (0.9–14.0), and CyFluTBI-2 3.6 (1.7–6.5) x 107/kg (p=.01). Results: Engraftment was not significantly different for the 3 groups (CyFluTBI-1 97% (92–100) vs. CyTBI 89% (82–96) vs. CyFluTBI-2 87% (80–94) (p=.06). Patients receiving a total CD34+ cell dose > 2.5 x 106/kg had significantly better engraftment ( 6.5, 98% [94–100], p<.01). Incidence of grades II-IV GVHD was higher after CyFluTBI-2 (51% [40–62]) as compared to CyFluTBI-1 (25% [11–39]) or CyTBI 37% (25–49) (p<.01) in univariate, but not in multivariate analysis after adjusting for age and disease risk. While treatment-related mortality (TRM) at 2 yrs was similar in univariate analysis (CyFluTBI-1, 11% [1–21] vs. CyFluTBI–2, 32% [22–42] vs. CyTBI 32% [22–42], p=.07), after adjusting for age and disease risk TRM was higher for the CyTBI (RR 3.5 [1.1–9.2], p=.03) vs. CyFluTBI-1. The relapse risk at 4 yrs for CyFluTBI-1 was 37% (19–55), CyFluTBI-2 19% (10–28), and CyTBI 28% (18–38) (p=.19). The LFS at 4 yrs for CyFluTBI-1 was 52% (34–70), CyFluTBI-2 49% (38–60), and CyTBI 37% (25–49) (p=.46). In multivariate analysis, only high risk disease was associated with higher relapse risk (RR 2.0;95%CI,1.0–3.9;p=.05) and mortality (RR 2.2;95%CI,1.4–3.4;p<.01). Notably, cell dose and HLA match had no effect on any outcome in multivariate analysis. Conclusions: Use of two partially HLA matched UCB units has increased the applicability of UCB particularly in adult recipients. As a result all UCB grafts contain >2.5 x 107 nucleated cells/kg at cryopreservation, limiting the negative effect of low cell dose on engraftment and survival and reducing the negative impact of HLA mismatch previously reported.
GPU-based iterative cone-beam CT reconstruction using tight frame regularization

The x-ray imaging dose from serial cone-beam computed tomography (CBCT) scans raises a clinical concern in most image-guided radiation therapy procedures. It is the goal of this paper to develop a fast graphic processing unit (GPU)-based algorithm to reconstruct high-quality CBCT images from undersampled and noisy projection data so as to lower the imaging dose. For this purpose, we have developed an iterative tight-frame (TF)-based CBCT reconstruction algorithm. A condition that a real CBCT image has a sparse representation under a TF basis is imposed in the iteration process as regularization to the solution. To speed up the computation, a multi-grid method is employed. Our GPU implementation has achieved high computational efficiency and a CBCT image of resolution 512 × 512 × 70 can be reconstructed in ~5 min. We have tested our algorithm on a digital NCAT phantom and a physical Catphan phantom. It is found that our TF-based algorithm is able to reconstruct CBCT in the context of undersampling and low mAs levels. We have also quantitatively analyzed the reconstructed CBCT image quality in terms of the modulation-transfer function and contrast-to-noise ratio under various scanning conditions. The results confirm the high CBCT image quality obtained from our TF algorithm. Moreover, our algorithm has also been validated in a real clinical context using a head-and-neck patient case. Comparisons of the developed TF algorithm and the current state-of-the-art TV algorithm have also been made in various cases studied in terms of reconstructed image quality and computation efficiency.
A welfare comparison of private and public monopoly

Abstract The cost function of a monopoly is C(q)=K + θq, where θ is unknown to the regulator. We evaluate various ownership and regulation regimes in terms of social welfare, determined by both the amount of total surplus and its distribution. Maximal welfare is achieved by the regulated public firm when its bias is pro-consumer, and also when it is pro-worker and θ is low enough. We compare an unregulated public firm with a private one regulated a la Loeb–Magat–Baron–Myerson and characterize the frontier, in parameter space, where one or the other dominates.
Intramolecular Cycloadditions of Photogenerated Azaxylylenes with Oxadiazoles Provide Direct Access to Versatile Polyheterocyclic Ketopiperazines Containing a Spiro-oxirane Moiety

Photogenerated azaxylylenes undergo intramolecular cycloadditions to 1,3,4-oxadiazole pendants, which are accompanied by concomitant release of dinitrogen, yielding functionalized ketopiperazinoquinolinols containing an oxirane moiety fused to the quinolinole moiety while spiro-connected to diketopiperazine. These primary photoproducts are reactive versatile intermediates which can be further derivatized under nucleophilic SN1- or SN2-like ring opening of the oxirane moiety. The oxidized quinolinones undergo new rearrangements under the conditions of the Schmidt reaction, leading to unprecedented triazacanoindolinones.
Synthesis of Substituted Piperidines from N,N-Bis[(benzotriazol-1-yl)methyl]amines.

N,N-Bis[(benzotriazol-1-yl)methyl]benzylamines and N,N-bis[(benzotriazol-1-yl)methyl](p-N‘,N‘-dimethylphenyl)amine on reaction with allyltrimethylsilanes yielded substituted piperidines. Other N,N-bis[(benzotriazol-1-yl)methyl]anilines (unsubstituted and p-CH3, OCH3, Cl) gave julolidines (2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij] quinoline).
A low - mass central black hole in the bulgeless Seyfert 1 galaxy NGC 4395

NGC 4395 is one of the least luminous and nearest known type 1 Seyfert galaxies, and it also lacks a bulge. We present a Hubble Space Telescope (HST) I-band image of its nuclear region and Keck high-resolution (~8 km s-1) echelle spectra containing the Ca II near-infrared triplet. In addition to the unresolved point source, there is a nuclear star cluster of size r ≈ 3.9 pc; the upper limit on its velocity dispersion is only 30 km s-1. We thus derive an upper limit of ~6.2 × 106 M☉ for the mass of the compact nucleus. Based on the amount of spatially resolved light in the HST image, a sizable fraction of this is likely to reside in stars. Hence, this estimate sets a stringent upper limit on the mass of the central black hole. We argue, from other lines of evidence, that the true mass of the black hole is likely to be ~104-105 M☉. Although the black hole is much less massive than those thought to exist in classical active galactic nuclei (AGNs), its accretion rate of Lbol/LEdd ≈ 2 × 10-2 to 2 × 10-3 is consistent with the mass-luminosity relation obeyed by classical AGNs. This may explain why NGC 4395 has a high-excitation (Seyfert) emission-line spectrum; active galaxies having low-ionization spectra seem to accrete at significantly lower rates. NGC 4395, a pure disk galaxy, demonstrates that supermassive black holes are not associated exclusively with bulges.
Observational Consequences of Fine-Structure Line Optical Depths on Infrared Spectral Diagnostics

It has long been known that infrared fine-structure lines of abundant ions, such as the (O iii) 88 mm line, can become optically thick in H ii regions under certain high-luminosity conditions. This could mitigate their potential as diagnostic tools, especially if the source is too dusty for optical spectroscopy to otherwise determine the system's parameters. We examined a series of photoionization calculations that were designed to push the nebulae into the limit where many IR lines should be quite optically thick. We find that radiative transfer effects do not significantly change the observed emission-line spectrum. This is due to a combination of grain absorption of the hydrogen ionizing continuum and the fact that the correction for stimulated emission in these lines is large. Given these results and the likelihood that real objects have nonthermal line broadening, it seems unlikely that line optical depth presents a problem in using these lines as diagnostics of the physical conditions or chemical composition.
Total synthesis of the sesquiterpene (+/-)-illudin C via an intramolecular nitrile oxide cycloaddition.

A convergent total synthesis of illudin C is described. The tricyclic ring system of the natural product was quickly assembled from cyclopropane and cyclopentene precursors via a novel oxime dianion coupling reaction and a subsequent intramolecular nitrile oxide−olefin cycloaddition.
Disappearance of the Deepwater Sculpin (Myoxocephalus Thompsoni) from Lake Ontario: The Keystone Predator Hypothesis

Disappearance of the deepwater sculpin (Myoxocephalus thompsoni) from Lake Ontario during the early 1950s is unexplained. I suggest that a contributing factor to this local extinction may have been increased competition with or predation on younger deepwater sculpin lifestages by the sympatric slimy sculpin (Cottus cognatus) that was precipitated by the loss of piscivores from the lake. Habitat and diet of adult slimy sculpins and young deepwater sculpins overlap in the Great Lakes and both species were heavily preyed upon by the lake trout (Salvelinus namaycush) and burbot (Lota lota) in Lake Ontario. It is hypothesized that predation on sculpins may have prevented either species from monopolizing the benthic offshore regions of Lake Ontario.
Stereodivergency in Catalytic Asymmetric Conjugate Addition Reactions of Glycine (Ket)imines

Stereodivergent catalytic asymmetric conjugate reactions of glycine (ket)imines with nitroalkenes have been achieved using various chiral catalyst systems derived from a multidentate amino alcohol (1). The stepwise nature of the [3 + 2] cycloaddition reactions of N-metalated azomethine ylides has also been demonstrated by highly enantio- and diastereoselective syntheses of exo-5 and endo-8 from the respective syn-4 and anti-7 conjugate addition products in a one-pot tandem fashion.
Weak order on complete quadrics

Using an action of the Richardson-Springer monoid on involutions, we study the weak order on the variety of complete quadrics. Maximal chains in the poset are explicitly determined. Applying results of Brion, our calculations describe certain cohomology classes in the complete flag variety.
Localized Functional Principal Component Analysis

We propose localized functional principal component analysis (LFPCA), looking for orthogonal basis functions with localized support regions that explain most of the variability of a random process. The LFPCA is formulated as a convex optimization problem through a novel deflated Fantope localization method and is implemented through an efficient algorithm to obtain the global optimum. We prove that the proposed LFPCA converges to the original functional principal component analysis (FPCA) when the tuning parameters are chosen appropriately. Simulation shows that the proposed LFPCA with tuning parameters chosen by cross-validation can almost perfectly recover the true eigenfunctions and significantly improve the estimation accuracy when the eigenfunctions are truly supported on some subdomains. In the scenario that the original eigenfunctions are not localized, the proposed LFPCA also serves as a nice tool in finding orthogonal basis functions that balance between interpretability and the capability of exp...
Gravitational field measurement with an equilibrium ensemble of cold atoms

A new approach to the measurement of gravitational fields with an equilibrium ensemble of ultra-cold alkali atoms confined in a cell of volume V is investigated. The proposed model of the gravitational sensor is based on a variation of the density profile of the ensemble due to a changing of gravitational field. Measuring the atomic density variations of the ensemble is accomplished through the method of electromagnetically induced transparency.
Federalism and Safety on America's Highways

Safety on America's highways has long been an important state policy issue, but since the 1960s Congress has used incentive grants, crossover sanctions that threaten to withhold federal highway funds, and diversionary sanctions that force states to use highway funds for safety purposes as a means of compelling states to adopt traffic safety policies. In an effort to promote public health, Congress has, at times, pushed states to adopt lower speed limits, mandatory motorcycle helmet laws, occupant protection laws, and laws designed to deter impaired driving. This article examines which fiscal tools have been effective in getting states to adopt traffic safety policies, how states have responded to changes in federal priorities on public health goals, and the implications of these policy efforts for public health.
Localization of the noradrenergic nervous system in human brain.

Abstract Recent improvements in the immunofluorescence technique have made possible the localization of dopamine-β-hydroxylase in neuron cell bodies, axon fibers and terminal fibers in brain. This technique compares favorably with the Falck and Hillarp histofluorescence technique for visualization of catecholamines. The immunofluorescence technique has several advantages that make it more applicable to post-mortem tissue. Preliminary results of dopamine-β-hydroxylase localization in human brain are presented.
Periodic tilting of Saturn's plasma sheet

[1] From the vantage of the dawn sector, the INCA instrument on Cassini imaged neutral hydrogen atoms (20–50 keV) emitted from the center of the Saturn's plasma sheet for five days during late 2004. Points along the center of the plasma sheet were found from contoured images projected onto the noon-midnight plane; points within 20 RS of Saturn were fitted to straight lines, and the slopes of these lines were examined as a function of time at one hour resolution. The slopes vary between ∼17° and ∼24° with a period of 10.80 hours, the same as that of Saturn kilometric radiation (SKR). This periodic tilting of the plasma sheet is in phase with SKR radiation in the sense that the maximum tilt angle occurs when the maximum in the SKR power occurs, and the tilt angle periodicity has a phase angle of ∼47° in SLS-3 longitude.
Discovery of the Gluon

The experimental discovery of the first Yang–Mills non-Abelian gauge particle — the gluon — in the spring of 1979 is summarized, together with some of the subsequent developments, including the role of the gluon in the recent discovery of the Higgs particle.
ADAM: a generalized data management system

ADAM is a computer program system built by The MITRE Corporation for use in the MITRE/ESD Systems Design Laboratory as a tool to aid the design and evaluation of data management systems. ADAM operates on the IBM 7030 (STRETCH) computer and has been operational since early 1965.
LOAN COMMITMENTS AND OPTIMAL MONETARY POLICY

Abstract With loan commitments negotiated in advance, the use of ‘tight money’ to restrain nominal spending has asymmetric effects upon different categories of borrowers. This can reduce efficiency, even though aggregate demand is stabilized. An equilibrium model of financial intermediation with loan commitments is developed, and used to analyze the welfare consequences of alternative monetary policies. If demand uncertainty relates primarily to the number of borrowers rather than to each one's demand for credit, an interest-rate smoothing policy is optimal.
Applications of circumscription to formalizing common-sense knowledge

We present a new and more symmetric version of the circumscription method of nonmonotonic reasoning first described in (McCarthy 1980) and some applications to formalizing common sense knowledge. The applications in this paper are mostly based on minimizing the abnormality of different aspects of various entities. Included are nonmonotonic treatments of is-a hierarchies, the unique names hypothesis, and the frame problem. The new circumscription may be called formula circumscription to distinguish it from the previously defined domain circumscription and predicate circumscription. A still more general formalism called prioritized circumscription is briefly explored.
Refined Neutron Star Mass Determinations for Six Eclipsing X-Ray Pulsar Binaries

We present an improved method for determining the mass of neutron stars in eclipsing X-ray pulsar binaries and apply the method to six systems, namely, Vela X-1, 4U 1538-52, SMC X-1, LMC X-4, Cen X-3, and Her X-1. In previous studies to determine neutron star mass, the X-ray eclipse duration has been approximated analytically by assuming that the companion star is spherical with an effective Roche lobe radius. We use a numerical code based on Roche geometry with various optimizers to analyze the published data for these systems, which we supplement with new spectroscopic and photometric data for 4U 1538-52. This allows us to model the eclipse duration more accurately and thus calculate an improved value for the neutron star mass. The derived neutron star mass also depends on the assumed Roche lobe filling factor β of the companion star, where β = 1 indicates a completely filled Roche lobe. In previous work a range of β between 0.9 and 1.0 was usually adopted. We use optical ellipsoidal light-curve data to constrain β. We find neutron star masses of 1.77 ± 0.08 M ☉ for Vela X-1, 0.87 ± 0.07 M ☉ for 4U 1538-52 (eccentric orbit), 1.00 ± 0.10 M ☉ for 4U 1538-52 (circular orbit), 1.04 ± 0.09 M ☉ for SMC X-1, 1.29 ± 0.05 M ☉ for LMC X-4, 1.49 ± 0.08 M ☉ for Cen X-3, and 1.07 ± 0.36 M ☉ for Her X-1. We discuss the limits of the approximations that were used to derive the earlier mass determinations, and we comment on the implications our new masses have for observationally refining the upper and lower bounds of the neutron star mass distribution.
MIXED MODEL AND ESTIMATING EQUATION APPROACHES FOR ZERO INFLATION IN CLUSTERED BINARY RESPONSE DATA WITH APPLICATION TO A DATING VIOLENCE STUDY

The NEXT Generation Health study investigates the dating violence of adolescents using a survey questionnaire. Each student is asked to affirm or deny multiple instances of violence in his/her dating relationship. There is, however, evidence suggesting that students not in a relationship responded to the survey, resulting in excessive zeros in the responses. This paper proposes likelihood-based and estimating equation approaches to analyze the zero-inflated clustered binary response data. We adopt a mixed model method to account for the cluster effect, and the model parameters are estimated using a maximum-likelihood (ML) approach that requires a Gaussian–Hermite quadrature (GHQ) approximation for implementation. Since an incorrect assumption on the random effects distribution may bias the results, we construct generalized estimating equations (GEE) that do not require the correct specification of within-cluster correlation. In a series of simulation studies, we examine the performance of ML and GEE methods in terms of their bias, efficiency and robustness. We illustrate the importance of properly accounting for this zero inflation by reanalyzing the NEXT data where this issue has previously been ignored.
Laser collimation of an atomic gallium beam

We have laser collimated a gallium atomic beam in one dimension using the linear-perpendicular-linear polarization gradient technique. Operating on the cycling 4p{sup 2}P{sub 3/2}(F=3){yields}4d{sup 2}D{sub 5/2}(F=4) transition at 294.45 nm, the full angular divergence of the atomic beam was reduced to 0.3 mrad, corresponding to a transverse velocity of {+-}11 cm/s, about one-half the Doppler cooling limit. The dependence of the cooling efficiency on the laser detuning and power was investigated. Optical pumping of the atoms out of the 4p{sup 2}P{sub 3/2}(F=3) state by the cooling laser was observed. Repumping schemes were investigated and found to successfully repopulate the cooled F=3 hyperfine state.
Using New Technology to Improve Assessment

What are the areas of testing that will be most affected by new technology“ Who is doing work on the cutting edge of these areas“ What will be the ultimate effect of these innovations“
An Intertemporal Model of International Capital Market Segmentation

This paper develops an intertemporal model of international capital market segmentation. Within the model, under various forms of segmentation/integration, the equilibrium asset prices and allocations, the risk-free interest rate, and the intertemporal consumption behavior and welfares of two countries are derived and compared. It is shown that the equilibrium interest rate is increased on integration, and that integrating markets may be significantly welfare decreasing for one of the countries. Conditions that may lead to a decrease in welfare are investigated. The conclusions as to the effects of segmentation on asset prices in the mean-variance model of the existing finance segmentation literature are also shown to break down in an intertemporal model.
Waves in periodic structures with imperfections

Abstract The study of wave propagation in structures and discrete or continuous media has a significant history which follows from the examination of the dynamics of atomic and molecular lattices. Relatively recently, some of these ideas have been transferred and applied to the dynamic behavior of engineered structures. In particular, structures with periodic and almost periodic topologies and material properties have been extensively studied and important conclusions drawn regarding their energy-transmission properties. The attraction to wave propagation models is due to the efficient nature of the analytical tools available to study how energies of different frequency content are propagated or filtered by the structure. Such properties of a structure are profoundly affected by any imperfections or ‘near-periodicities’. It has been found that imperfections will have the effect of localizing energies about them, thus not allowing the development of normal modes of vibration as would be observed when assuming a perfect structure. It is envisioned that such understanding will permit the analyst to take advantage of localization effects to isolate locations experiencing loading. Additional applications possibly include the modeling of composite and layered structures and cracks. Also, one expects that structures with periodic boundary conditions will experience some sort of localization of energies in certain frequency ranges. Of particular interest there is the possibility that these ideas may apply to the concept of functionally graded materials and composites.
Prosecutorial Resources, Plea Bargaining, and the Decision to Go to Trial

This article examines the strategic interaction between a defendant and a prosecutor during the plea bargaining process. A four-stage game of incomplete information is developed where the defendant's guilt or innocence is private information but the amount of resources available to the prosecutor is common knowledge. The basic result of the article is that equilibrium is semiseparating; the plea offer is accepted by a proportion of the guilty defendants and is rejected by all of the innocent defendants and the remaining guilty defendants. In this model an increase in the resources available to the prosecutor increases the proportion of guilty defendants who accept plea offers. Although the prosecutor is unable to generate complete separation of the guilty and innocent defendants through the plea bargaining process, prosecutorial resources are beneficial from a societal standpoint.
Chemistry and cooling of transition metal cluster ions

Abstract Singly charged clusters of V, Cr, Mn, Fe, and Co metal and metal oxides, containing up to four metal atoms, are produced in a sputtering source. Radiofrequency ion guides are used to store the clusters for cooling by collisional relaxation and to study gas-phase reactions of the clusters. Preliminary studies of reactions of “hot” metal and metal oxide clusters with ethylene, studies of cooling efficiency of the clusters, and a comparison of reactions of cooled and hot cobalt clusters at several translational energies are reported.
Highly diastereoselective 5-hexenyl radical cyclizations with Lewis acids and carbohydrate scaffolds.

Carbohydrates as removable chiral scaffolds for free radical cyclizations were examined for the first time. This investigation illustrates the utility of two inexpensive carbohydrate derivatives as sources of asymmetry for 5-hexenyl radical cyclizations. Diastereomeric ratios as high as 100:1 were achieved with an ester-appended (+)-isosorbide hexose and 70:1 for a diol-protected d-xylose pentose. Temperature dependence, Lewis acids, and solvents were all examined. By correlation with known compounds, the newly generated chiral centers were of the (S)-configuration.
Early Surgical Alignment for Congenital Esotropia

To provide sufficient numbers of patients varying in age of initial adequate surgical alignment for congenital esotropia, 162 patients managed by seven ophthalmologists in three countries were personally examined by the author and the results compiled for a clinical study. From this population group, 106 patients were chosen who had reliable answers, satisfactory alignment, and an ophthalmologist's confirmation examination of the congenital nature of the problem by at least 1 year of age. The results of sensory testing showed that those adequately aligned by the age of 6 months vs 12 months vs 24 months were not statistically different, but those patients aligned after 24 months of age demonstrated a significantly lower percentage with evidence for binocularity (P less than 0.001). Surgical alignment in the congenital esotropic patient should be accomplished by 2 years of age to attain the highest yield of binocular function.
Anisotropy in the interaction of ultracold dysprosium

The nature of the interaction between ultracold atoms with a large orbital and spin angular momentum has attracted considerable attention. It was suggested that such interactions can lead to the realization of exotic states of highly correlated matter. Here, we report on a theoretical study of the competing anisotropic dispersion, magnetic dipole–dipole, and electric quadrupole–quadrupole forces between two dysprosium atoms. Each dysprosium atom has an orbital angular momentum of L = 6 and a magnetic moment of μ = 10 μB. We show that the dispersion coefficients of the ground state adiabatic potentials lie between 1865 a.u. and 1890 a.u., creating a non-negligible anisotropy with a spread of 25 a.u. and that the electric quadrupole–quadrupole interaction is weak compared to the other interactions. We also find that for interatomic separations R < 50a0 both the anisotropic dispersion and magnetic dipole–dipole potential are larger than the atomic Zeeman splittings for external magnetic fields of order 10 G to 100 G. At these separations the atomic angular momentum can be reoriented. We finish by describing two scattering models for these inelastic m-changing collisions. A universal scattering theory is used to model loss due to the anisotropy in the dispersion and a Born approximation is used to model losses from the magnetic dipole–dipole interaction for the 164Dy isotope. These models find loss rates that are of the same order of magnitude as the experimental value.
Soft-X-ray microscope using fourier transform holography

Abstract A Fourier transform holographic microscope with an anticipated resolution of better than 100 nm has been built. Extensive testing of the apparatus has begun. Preliminary results include the recording of interference fringes using 3.6-nm X-rays. The microscope employs a charge-coupled-device (CCD) detector array of 576 × 384 elements. The system is illuminated by soft X-rays from a high-brightness undulator. The reference point source is formed by a Fresnel zone plate with a finest outer zone width of 50 nm. Sufficient temporal coherence for hologram formation is obtained by a spherical grating monochromator. The X-ray hologram intensities at the recording plane are to be collected, digitized and reconstructed by computer. Data acquisition is under CAMAC control, while image display and off-line processing takes place on a VAX graphics workstation. Computational models of Fourier transform hologram synthesis, and reconstruction in the presence of noise, have demonstrated that numerical methods in two dimensions are feasible and that three-dimensional information is potentially recoverable.
On the throughput capacity of information-centric networks

Wireless information-centric networks consider storage one of the network primitives, and propose to cache data within the network in order to improve latency to access content and reduce bandwidth consumption. We study the throughput capacity of an information-centric network when the data cached in each node has a limited lifetime. The results show that with some fixed request and cache expiration rates, the network can have the maximum throughput order of 1/√n and 1/log n in cases of grid and random networks, respectively. Comparing these values with the corresponding throughput with no cache capability (1/n and 1/√(n log n) respectively), we can actually quantify the asymptotic advantage of caching. Moreover, since the request rates will decrease as a result of increasing download delays, increasing the content lifetimes according to the network growth may result in higher throughput capacities.
COMPUTER-AIDED GEOMETRIC RECONSTRUCTION OF FLETCHER-SUIT SOURCE POSITIONS

A computer-aided method for reconstruction of the source positions of a Fletcher-Suit applicator has been developed. The tandem source positions are determined by digitizing of the tip and two arbitrary points on the shaft from each of two orthogonal simulator films. A colpostat source position is reconstructed by digitizing of a single point on the endcap and three arbitrary points on the cylindrical sidewalls of the colpostat on the films. This computer-aided method considers the true projection geometry and applicator shape and permits localization of the source positions to within a mean error of less than 1 mm. Compared with the conventional method, the new approach (1) is more time efficient because only a few easily identified points are digitized, (2) allows localization when the tandem sources are shifted by a spacer or when colpostat sources are difficult to visualize on the lateral film, and (3) is more accurate than the conventional technique because no manual drawing of source positions on films is involved.
Minimizing time-space cost for database version control

We introduce the concept of a version graph to model the problem of minimizing the combined cost of storage space and version regeneration time for database version control systems. We show that, in general, this problem and several of its variations are NP-complete. Several heuristics are developed, and performance guarantees for these heuristics are obtained. We also present linear time algorithms for special classes of version graphs; these special classes are likely to apply in many version control systems.
Multiple network alignment on quantum computers

Comparative analyses of graph-structured datasets underly diverse problems. Examples of these problems include identification of conserved functional components (biochemical interactions) across species, structural similarity of large biomolecules, and recurring patterns of interactions in social networks. A large class of such analyses methods quantify the topological similarity of nodes across networks. The resulting correspondence of nodes across networks, also called node alignment, can be used to identify invariant subgraphs across the input graphs. Given $$k$$k graphs as input, alignment algorithms use topological information to assign a similarity score to each $$k$$k-tuple of nodes, with elements (nodes) drawn from each of the input graphs. Nodes are considered similar if their neighbors are also similar. An alternate, equivalent view of these network alignment algorithms is to consider the Kronecker product of the input graphs and to identify high-ranked nodes in the Kronecker product graph. Conventional methods such as PageRank and HITS (Hypertext-Induced Topic Selection) can be used for this purpose. These methods typically require computation of the principal eigenvector of a suitably modified Kronecker product matrix of the input graphs. We adopt this alternate view of the problem to address the problem of multiple network alignment. Using the phase estimation algorithm, we show that the multiple network alignment problem can be efficiently solved on quantum computers. We characterize the accuracy and performance of our method and show that it can deliver exponential speedups over conventional (non-quantum) methods.
Imaging the Connectome

Connectional maps of the brain may have value in developing models of both how the brain works and how it fails when subsets of neurons or synapses are missing or misconnected. I am eager to obtain such maps in neonatal animals because of a longstanding interest in the ways neuromuscular circuitry is modified during early postnatal life as axonal input to muscle fibers is pruned. Work in my laboratory has focused on obtaining complete wiring diagrams (“connectomes”) of the projections of motor neuron axons in young and adult muscles. Each data set is large and typically made up of hundreds of confocal microscopy stacks of images which tile the 3-dimensional volume of a muscle. As a first step to analyze these data sets we developed computer assisted segmentation approaches and to make this task easier, have developed now second generation “Brainbow” transgenic mice that in essence segment each axon by a unique fluorescent spectral hue. This effort has led to new insights into the developmental processes which help the mammalian nervous system mold itself based on experience. In brain however, as opposed to muscle, the high density of neuropil is overwhelming, which has thus far precluded using the fluorescence approaches that have worked in the peripheral nervous system. We have thus developed an automated physical sectioning strategy that generates thousands of ultra-thin (∼25-30 nm) sections on a firm plastic tape. This method makes large scale serial microscopic analysis of brain volumes more routine. We have generated “saturated” segmentations of cerebral cortex and wiring diagrams in thalamus to track every axon and annotate every synapse in neural circuits.
THE COMPLETENESS OF PROPOSITIONAL RESOLUTION A SIMPLE AND CONSTRUCTIVE PROOF

It is well known that the resolution method (for propositional logic) is com- plete. However, completeness proofs found in the literature use an argument by contra- diction showing that if a set of clauses is unsatisfiable, then it must have a resolution refutation. As a consequence, none of these proofs actually gives an algorithm for produc- ing a resolution refutation from an unsatisfiable set of clauses. In this note, we give a simple and constructive proof of the completeness of propositional resolution which consists of an algorithm together with a proof of its correctness.
The renormalization group for correlated scales: one-stage versus two-stage running

Abstract Nonrelativistic bound states have two low energy scales, a soft scale μ S of order mv and an ultrasoft scale μ U of order mv 2 . In two-stage running, the soft and ultrasoft scales are lowered from m to mv , and then the ultrasoft scale is lowered from mv to mv 2 . In one-stage running, the two scales are lowered in a correlated way using a subtraction velocity. We compare these two methods of summing logarithms and show that only the correlated running in velocity space of the one-stage method correctly reproduces the logarithms in nonrelativistic bound states in QED. The argument for one-stage running is general, and should apply to any system with correlated scales.
Recommending related papers based on digital library access records

An important goal for digital libraries is to enable researchers to more easily explore related work. While citation data is often used as an indicator of relatedness, in this paper we demonstrate that digital access records (e.g. http-server logs) can be used as indicators as well. In particular, we show that measures based on co-access provide better coverage than co-citation, that they are available much sooner, and that they are more accurate for recent papers.
Reduction Of The Effects Of Scattering By Laser Annealing Of Optical Waveguides And By Use Of Integrated Waveguide Detection

The use of laser annealing with a CO2 laser to improve the quality of both Corning 7059 and phosphosilicate glass (PSG) thin-film optical waveguides will be described. Dark-field photomicrographs taken before and after laser annealing imply that both surface and bulk defects are removed by laser annealing. Waveguide attenuation is typically measured to be on the order of 10 dB/cm before laser annealing, while after laser annealing values significantly lower than 0.1 dB/cm have been measured. We shall discuss the integration of a photodetector array and the optical waveguide structure, and the fact that for such a structure less scattering reaches adjacent array elements than when these two structures are not integrated. The dynamic range of the integrated optical signal process of interest would thus be expected to be greater for the integrated configuration.
Monetary Policy Rules and Business Cycles

Basic features of business cycle properties under both exogenous and endogenous monetary policy rules are examined in calibrated dynamic stochastic general equilibrium models with nominal rigidities (the nominal wage contract model, the monopolistic competition model with price adjustment costs and a combination of these models). The experiments show that the difference in business cycle features under exogenous and endogenous monetary policy rules is as large as the change generated by introducing nominal rigidities (and monetary disturbances). This result suggests that, for monetary business cycle research, developing a proper way to incorporate endogenous monetary policy rules may be as important as developing new transmission mechanisms of monetary policy disturbances.
Time-dependent perturbation theory for vibrational energy relaxation and dephasing in peptides and proteins

Without invoking the Markov approximation, we derive formulas for vibrational energy relaxation (VER) and dephasing for an anharmonic system oscillator using a time-dependent perturbation theory. The system-bath Hamiltonian contains more than the third order coupling terms since we take a normal mode picture as a zeroth order approximation. When we invoke the Markov approximation, our theory reduces to the Maradudin-Fein formula which is used to describe the VER properties of glass and proteins. When the system anharmonicity and the renormalization effect due to the environment vanishes, our formulas reduce to those derived by and Mikami and Okazaki [J. Chem. Phys. 121, 10052 (2004)] invoking the path-integral influence functional method with the second order cumulant expansion. We apply our formulas to VER of the amide I mode of a small amino-acid like molecule, N-methylacetamide, in heavy water.
A rose by any other name ...?: What members of the general public prefer to call “climate change”

Unlike many other environmental problems, the terms used to describe the phenomenon of increasing atmospheric concentrations of anthropogenic greenhouse gases are many, with multiple and sometimes conflicting meanings. Whether there are meaningful distinctions in public perceptions of "global warming," "climate change," and "global climate change" has been a topic of research over the past decade. This study examines public preferences for these terms based on respondent characteristics, including climate change beliefs, political affiliation, and audience segment status derived from the "Global Warming's Six Americas" classification. Certainty of belief in global warming, political affiliation and audience segment status were found to be the strongest predictors of preference, although "I have no preference" was the modal response. Global warming appears to be a more polarizing term than climate change, preferred most by people already concerned about the issue, and least by people who don't believe climate change is occurring. Further research is needed to identify which of these two names promotes the engagement of people across the spectrum of climate change beliefs in constructive dialogue about the issue.
Probability density, diagrammatic technique, and epsilon expansion in the theory of wave turbulence

We apply the methods of field theory to study the turbulent regimes of statistical systems. First we show how one can find their probability densities. For the case of the theory of wave turbulence with four-wave interaction we calculate them explicitly and study their properties. Using those densities we show how one can in principle calculate any correlation function in this theory by means of direct perturbative expansion in powers of the interaction. Then we give the general form of the corrections to the kinetic equation and develop an appropriate diagrammatic technique. This technique, while resembling that of ϕ4 theory, has many new distinctive features. The role of the ϵ = d − 4 parameter of ϕ4 theory is played here by the parameter κ = β + d − α − γ where β is the dimension of the interaction, d is the space dimension, α is the dimension of the energy spectrum and γ is the “classical” wave density dimension. If κ > 0 then the Kolmogorov index is exact, and if κ < 0 then we expect it to be modified by the interaction. For κ a small negative number, α < 1 and a special form of the interaction we compute this modification explicitly. We neglect the encountered IR divergencies with the intend to study them in a later publication.
Improved Synthesis of a C30H12 Buckybowl via Benzylic Oxidation with Benzeneseleninic Anhydride

The authors have provided an improved synthesis of 1,2,5,6-tetraketopyracene (6), in that three steps have been replaced with one high-yield step. Moreover, a very unreliable step has been eliminated. In turn, this has led to an improved synthesis of buckybowl 3 using 6 as an intermediate. Alternatively, the authors have also provided a new route to 3 utilizing the benzeneseleninic anhydride conversion of 7 to 8. The authors hope that this new route will find application in other buckybowl syntheses as well. 7 refs.
On noncommutative multi-solitons

Solitons in noncommutative scalar field theories possess many stringy features. In particular, multi-solitons in these theories behave like multiple D- branes. A useful moduli space description for multi-solitons exists which reproduces stringy features of D-brane moduli spaces in a simple way via properties of special projection operators. In particular, they are equivalent to a Hilbert scheme resolution of symmetric product spaces.
Effects of an African grass invasion on Hawaiian shrubland nitrogen biogeochemistry

African perennial C4 grasses are highly successful invaders in Hawaiian ecosystems. We examined the effects of African molasses grass (Melinis minutiflora Beauv.) on Hawaiian shrubland nitrogen (N) dynamics without the influence of fire disturbance. Vegetation tissue carbon and nitrogen chemistry, soil inorganic N pools, net N mineralization rates, and total soil N were studied in three adjacent areas: a monospecificMelinis grassland, a mixed grass/shrubland mosaic, and an un-invaded shrubland.Melinis plots within the mosaic area exhibited the largest inorganic N pools and fastest net N mineralization rates, but were temporally variable with grass phenology. Un-invaded shrubland plots contained the smallest inorganic N pools and lowest net N mineralization rates. Grass foliar C:N and litter C:N were lower than those of common shrubland species, providing one possible link between species and ecosystem N dynamics at this site. The combined effects of N cycle modification, successful light competition, and fire-cycle enhancement make the invasion ofMelinis a significant perturbation to Hawaiian shrubland ecosystem function and successional dynamics. ei]Section editor H Lambers