cssi/SciSciGPT-SciSciNet huggingface dataset:
Reducing the Effects of Detrimental Instances

Not all instances in a data set are equally beneficial for inducing a model of the data. Some instances (such as outliers or noise) can be detrimental. However, at least initially, the instances in a data set are generally considered equally in machine learning algorithms. Many current approaches for handling noisy and detrimental instances make a binary decision about whether an instance is detrimental or not. In this paper, we 1) extend this paradigm by weighting the instances on a continuous scale and 2) present a methodology for measuring how detrimental an instance may be for inducing a model of the data. We call our method of identifying and weighting detrimental instances reduced detrimental instance learning (RDIL). We examine RDIL on a set of 54 data sets and 5 learning algorithms and compare RDIL with other weighting and filtering approaches. RDIL is especially useful for learning algorithms where every instance can affect the classification boundary and the training instances are considered individually, such as multilayer perceptrons trained with back propagation (MLPs). Our results also suggest that a more accurate estimate of which instances are detrimental can have a significant positive impact for handling them.
Hamiltonicity, independence number, and pancyclicity

A graph on n vertices is called pancyclic if it contains a cycle of length @? for all 3@?@?@?n. In 1972, Erdos proved that if G is a Hamiltonian graph on n>4k^4 vertices with independence number k, then G is pancyclic. He then suggested that n=@W(k^2) should already be enough to guarantee pancyclicity. Improving on his and some other later results, we prove that there exists a constant c such that n>ck^7^/^3 suffices.
A numerical circulation model with topography for the Martian Southern Hemisphere

A quasi-geostrophic numerical model, including friction, radiation, and the observed planetary topography, is applied to the general circulation of the Martian atmosphere in the Southern Hemisphere at latitudes south of about 35 deg. Near equilibrium weather systems developed after about 5 model days. To avoid violating the quasi-geostrophic approximation, only 0.8 of the already smoothed relief was employed. Weather systems and velocity fields are strikingly tied to topography. A 2mb middle latitude jet stream is found of remarkably terrestrial aspect. Highest surface velocities, both horizontal and vertical, are predicted in western Hellas Planitia and eastern Argyre Planitia, which are observed to be preferred sites of origin of major Martian dust storms. Mean horizontal velocities and vertical velocities are found just above the surface velocity boundary layer.
Racial differences in hormone replacement therapy prescriptions.

Abstract Objective: To examine racial differences in hormone replacement therapy (HRT) use by analyzing the relative risks and rates of HRT prescriptions for black and white women. Methods: Data on visits to hospital outpatient departments and office-based physicians by black and white women aged 45–64 years were obtained from 25,203 visits sampled in the 1993–1995 National Ambulatory Medical Care Surveys and National Hospital Ambulatory Medical Care Surveys. The relative effect of race on the provision of an HRT prescription at an ambulatory visit was estimated by controlling confounders using logistic regression. Population-based rates of physician visits and visits with HRT prescriptions were also calculated to address issues involving access to care. Results: Approximately 98,787,000 annual visits were made by black and white women 45–64 years of age, 9.2% of which involved prescriptions for HRT. The percentage of visits by black women in which prescriptions for HRT were reported (4.5%) was roughly half that of white women (9.7%). The association persisted after controlling for type of physician, practice type, geographic region, payment source, and non-HRT prescription(s) (odds ratio 2.1; 95% confidence interval 1.5, 2.9). The rate of ambulatory care among black women (3.82 visits per year per woman) was virtually identical to that of white women (3.94 visits per year), whereas the rate of visits with HRT prescriptions for white women was twice as high as for black women (0.38 and 0.17 visits per year, respectively). Conclusion: Apparent racial differences in HRT use persist after controlling for physician and visit factors not explored in previous studies.
ON SUPERMULTIPLET TWISTING AND SPIN-STATISTICS

Twisting of off-shell supermultiplets in models with (1+1)-dimensional spacetime has been discovered in 1984, and was shown to be a generic feature of off-shell representations in worldline supersymmetry two decades later. It is shown herein that in all supersymmetric models with spacetime of four or more dimensions, this off-shell supermultiplet twisting, if nontrivial, necessarily maps regular (non-ghost) supermultiplets to ghost supermultiplets. This feature is shown to be ubiquitous in all fully off-shell supersymmetric models with (BV/BRST-treated) constraints.
Targeting retroviral integration

Retroviral vectorsarecurrently themost widely used method ofgenetransfer ingene therapy, inpartbecause theretroviral integration systemprecisely links thetherapeutic sequencestothehost chromosome with neat covalent bonds. DNA integration, however, comes with aprice. Retroviral integration systemsshowlittle targetsite specificity, andhaphazard insertions into a patient's chromosomes can createproblems. Integration nearcellular proto-oncogenesmay lead toectopic gene activation andcancer,not a desirable outcome of gene therapy (1).Retroviral integration can also inactivate genes(2). Recent findings on site-specific DNA integration by retroviruses andretrotransposons suggesta strategyforretrovirusbased gene therapy thatavoids
Deregulating the Transfer of Agricultural Technology: Lessons from Bangladesh, India, Turkey, and Zimbabwe

Many transition and developing economies have reduced direct public involvement in the production and trade of seed and other agricultural inputs. This trend creates opportunities for farmers to realize improved access to inputs, including technology from international private research. Unfortunately, input regulations often derail these opportunities by blocking private entry and the introduction of private technology. This study looks at the experience in Bangladesh, India, Turkey, and Zimbabwe to see whether regulations make a difference in agriculture and input industries in developing economies. In all countries, companies and farmers responded to regulatory reforms by introducing and adopting more new technology and by expanding the production, trade, and use of inputs. The increased use of private technology has brought higher yields and incomes, allowing farmers and consumers to reach higher levels of welfare. These results challenge governments to open their regulatory systems to allow market entry and the introduction of private technology through seeds and other inputs.
Improved Hanle effect measurement technique for fast ions.

Abstract An improved averaging technique for use with foil-excited fast ions is applied to a Hanle-effect measurement of the mean lifte τ of the 4p 2F° 7 2 level of Ar II. The result is τ = 9.5 ± 0.5 nsec. Other coherence measurements are are also reported.
Accelerating pathology image data cross-comparison on CPU-GPU hybrid systems

As an important application of spatial databases in pathology imaging analysis, cross-comparing the spatial boundaries of a huge amount of segmented micro-anatomic objects demands extremely data- and compute-intensive operations, requiring high throughput at an affordable cost. However, the performance of spatial database systems has not been satisfactory since their implementations of spatial operations cannot fully utilize the power of modern parallel hardware. In this paper, we provide a customized software solution that exploits GPUs and multi-core CPUs to accelerate spatial cross-comparison in a cost-effective way. Our solution consists of an efficient GPU algorithm and a pipelined system framework with task migration support. Extensive experiments with real-world data sets demonstrate the effectiveness of our solution, which improves the performance of spatial cross-comparison by over 18 times compared with a parallelized spatial database approach.
Absence of Mott Transition in an Exact Solution of the Short-Range, One-Band Model in One Dimension

The short-range, one-band model for electron correlations in a narrow energy band is solved exactly in the one-dimensional case. The ground-state energy, wave function, and the chemical potentials are obtained, and it is found that the ground state exhibits no conductor-insulator transition as the correlation strength is increased.
Finite plane and anti-plane elastostatic fields with discontinuous deformation gradients near the tip of a crack

In this paper the fully nonlinear theory of finite deformations of an elastic solid is used to study the elastostatic field near the tip of a crack. The special elastic materials considered are such that the differential equations governing the equilibrium fields may lose ellipticity in the presence of sufficiently severe strains.
Brain drain or overflow

drain" in recent years, no firm consensus has emerged as to whether or not one exists. Today we know much more about the international migration of professional manpower than we did five, four or even three years ago. But the "more" we know is mainly facts, and not all that many; men still have difficulty saying what the facts mean and deciding whether or not the brain drain constitutes a problem of "disturbing dimen sions"?as the Pearson Commission called it. Instead of mass movements of relatively unskilled and un tutored peoples into the world's empty spaces, international migration has increasingly become the movement of people with education seeking opportunities in more developed coun tries to use skills that education has given them. The dramatic increases in foreign study since World War II, the explosion of international communications and the decline in the cost of travel have combined to internationalize the market for edu cated manpower to a degree previously unknown. This widening of the market, combined with full employment in the West, has greatly increased competition for professional manpower, espe cially the competition for exceptional talent. For some em? ployers, this international competition has brought trouble; for many individuals it has brought opportunity. There can be no quarrel with the statement in the United Na tions Report1 that "highly trained personnel from many devel oping countries are emigrating to a few major developed coun tries, that the size of this flow is large and that it is increasing at a rapid rate." But there is great question whether this migration is seriously hurting the countries that are the net exporters of trained manpower. The surprising fact is that in most develop? ing countries the number of professionally trained people who are becoming available for home employment is rising, not fall ing, and in country after country the numbers are rising faster than their economies can absorb them. One certainly cannot make this statement about all countries, or even all underdevel
Strict Kneser–Poulsen conjecture for large radii

In this paper we prove the Kneser–Poulsen conjecture for the case of large radii. Namely, if a finite number of points in Euclidean space \({\mathbb{E}^n}\) is rearranged so that the distance between each pair of points does not decrease, then there exists a positive number r0 that depends on the rearrangement of the points, such that if we consider n-dimensional balls of radius r > r0 with centers at these points, then the volume of the union (intersection) of the balls before the rearrangement is not less (not greater) than the volume of the union (intersection) after the rearrangement. Moreover, the inequality is strict whenever the new point set is not congruent to the original one. Also under the same conditions we prove a similar result about surface volumes instead of volumes. In order to prove the above mentioned results we use ideas from tensegrity theory to strengthen the theorem of Sudakov (Dokl. Akad. Nauk SSSR 197:43–45, 1971), Alexander (Trans. Am. Math. Soc., 288(2):661–678, 1985) and Capoyleas and Pach (Discrete and computational geometry. American Mathematical Society, Providence, 1991), which says that the mean width of the convex hull of a finite number of points does not decrease after an expansive rearrangement of those points. In this paper we show that the mean width increases strictly, unless the expansive rearrangement was a congruence. We also show that if the configuration of centers of the balls is fixed and the volume of the intersection of the balls is considered as a function of the radius r, then the second highest term in the asymptotic expansion of this function is equal to \({-M_nr^{n-1}}\) , where Mn is the mean width of the convex hall of the centers. This theorem was conjectured by Balazs Csikos in 2009.
Who's minding the store? Motivating and monitoring hired managers at small, closely held commercial banks ☆

Abstract Small, closely held corporations must rely disproportionately on managerial shareholdings to mitigate the agency costs associated with hired managers, because market discipline and motivated outside monitors are typically absent for such firms. We study a random sample of 266 small, closely held US commercial banks with a broad range of ownership and management arrangements. Our results suggest that hiring an outside manager can improve profitability, but these gains depend on aligning hired managers with owners via managerial shareholdings. We find that over-utilizing this control mechanism results in entrenchment, while under-utilization is costly in terms of foregone profits.
Synthesis of metal–organic framework particles and thin films via nanoscopic metal oxide precursors

Metal–organic frameworks (MOFs) are a diverse family of hybrid inorganic–organic crystalline solids synthesized by assembling secondary building units (SBUs) and organic ligands into a periodic and porous framework. Microporous MOF materials, due to their high permeability and size selectivity, have attracted tremendous interest in gas storage and separation, large molecule adsorption, catalysis, and sensing. Despite the significant fabrication challenges, nanosized MOF particles can be fabricated to display enhanced gas storage and separation abilities in comparison to the parent MOF bulk counterparts under special synthesis conditions. So far, the majority of MOF nanocrystals have been derived from the controlled nucleation and growth of molecular precursors in homogeneous solutions. However, synthesis protocols based on nucleation and growth from dilute solution precursors are difficult to adapt to the synthesis of other nanoscopic materials, such as thin film and mixed-matrix membranes, which limits the practical applications of MOFs. This article discusses the current status of synthetic methods that have been utilized to fabricate MOF-based nanoscopic materials and ultrathin membranes from nanoscopic metal oxide precursors.
Design and validation of a power supply noise reduction technique

For the high-performance microprocessors with high-bandwidth I/O, the power supply noise needs to be controlled to ensure reliable high speed bus operation. This is generally done with high-quality package capacitors. These capacitors are generally lower equivalent series inductance (ESL) and lower equivalent series resistor (ESR). In this paper, we will present two implementations of an approach of using on-die resistors in series with the package capacitance to dampen the high-frequency noise. We will show by validation on the 90-nm technology that this technique is capable of reducing the noise by nearly 80% without adversely affecting the timings. The results of several validation experiments, including the measurement of noise and impedance of the I/O power delivery, and the post-layout simulation will also be presented.
Deciphering the Roles of Multicomponent Recognition Signals by the AAA + Unfoldase ClpX

ATP-dependent protein remodeling and unfolding enzymes are key participants in protein metabolism in all cells. How these often-destructive enzymes specifically recognize target protein complexes is poorly understood. Here, we use the well-studied AAA+ unfoldase-substrate pair, Escherichia coli ClpX and MuA transposase, to address how these powerful enzymes recognize target protein complexes. We demonstrate that the final transposition product, which is a DNA-bound tetramer of MuA, is preferentially recognized over the monomeric apo-protein through its multivalent display of ClpX recognition tags. The important peptide tags include one at the C-terminus ("C-tag") that binds the ClpX pore and a second one (enhancement or "E-tag") that binds the ClpX N-terminal domain. We construct a chimeric protein to interrogate subunit-specific contributions of these tags. Efficient remodeling of MuA tetramers requires ClpX to contact a minimum of three tags (one C-tag and two or more E-tags), and that these tags are contributed by different subunits within the tetramer. The individual recognition peptides bind ClpX weakly (KD>70 μM) but impart a high-affinity interaction (KD~1.0 μM) when combined in the MuA tetramer. When the weak C-tag signal is replaced with a stronger recognition tag, the E-tags become unnecessary and ClpX's preference for the complex over MuA monomers is eliminated. Additionally, because the spatial orientation of the tags is predicted to change during the final step of transposition, this recognition strategy suggests how AAA+ unfoldases specifically distinguish the completed "end-stage" form of a particular complex for the ideal biological outcome.
Automatic off-line multivariate data analysis

Many research problems in the social and physical sciences require the collection of large amounts of data of the simultaneously measured attributes of a phenomenon or process under investigation. Pattern recognition problems, in particular, yield data of multiple variables for each manifestation of the different sources of data. The automatic off-line multivariate analysis techniques described in this paper deal with the quantitative description of data of this type.
Distortion of a turbulent scalar upstream of axisymmetric objects

TECHNICAL NOTES are short manuscripts describing neve developments or important results of a preliminary nature. These Notes cannot exceed 6 manuscript pages and 3 figures; a page of text may be substituted for a figure and vice versa. After informal review by the editors, they may be published within a few months of the date of receipt. Style requirements are the same as for regular contributions (see inside back cover).
Building constrained peptidomimetics: a convenient approach to 3-phenyl-5-vinyl substituted proline derivatives

Abstract An approach to the synthesis of 3-phenyl-5-vinyl substituted prolines starting from readily available 2,3-disubstituted pentenoic acid derivatives is reported. The route converts the pentenoic acid derived starting materials into cyclic N-acyliminium ion precursors with the use of a hydroboration–Swern oxidation sequence. This overall transformation worked best when the initial alkylborane product was treated sequentially with excess MCPBA and then acetone prior to the Swern oxidation. In this way, a 70% yield of the desired N-acyliminium ion precursor could be obtained. Once in hand, the cyclic N-acyliminium ion precursor was used to make the desired 3-phenyl-5-vinyl substituted prolines.
Combined/simultaneous gust and oscillating compressor blade unsteady aerodynamics

Experiments are performed in a three-stage axial flow research compressor to investigate and quantify the simultaneous/combined gust- and motion-induced unsteady aerodynamic response of the first-stage rotor blades of thecompressor. The gust-response unsteady aerodynamics are experimentally modeled with a 2 per revolution forcing function. The torsion mode unsteady aerodynamics is investigated utilizing an experimental influence coefficient technique in conjunction with a unique drive system. Combined gust and oscillating unsteady aerodynamics are obtained by the superposition of the oscillating blade row and the gust-response unsteady aerodynamics. Simultaneous gust- and motion-induced unsteady aerodynamic responses are obtained by driving the torsion mode oscillation in the presence of the 2 per revolution forcing function. The effects of steady loading are quantified. Airfoil oscillation amplitude effects are also studied. The combined unsteady aerodynamics establishes superposition limitations at high oscillation amplitudes and high loading. In addition, the gust-blade motion phase angle is identified as a key parameter.
Early estimates of the strength of the nuclear spin-orbit force

Before the development of the nuclear shell model estimates of the strength of the nuclear spin-orbit interaction varied widely. Wheeler was the first to conclude that the nuclear spin-orbit interaction produces splittings of several MeV. This conclusion appeared, however, to be inconsistent with some experimental results that later turned out to be faulty.
Stability of delay impulsive systems with application to networked control systems

We establish asymptotic and exponential stability theorems for delay impulsive systems by employing Lyapunov functionals with discontinuities. Our conditions have the property that when specialized to linear delay impulsive systems, the stability tests can be formulated as Linear Matrix Inequalities (LMIs). Then we consider Networked Control Systems (NCSs) consisting of an LTI process and a static feedback controller connected through a communication network. Due to the shared and unreliable channels, sampling intervals become uncertain and variable. Moreover, samples may be dropped or experience uncertain and variable delays before arriving at the destination. We show that the resulting NCSs can be modelled by linear delay impulsive systems and we provide conditions for stability of the closed-loop system in terms of LMIs. By solving these LMIs, one can find a positive constant that determines an upper bound between each sampling time and the subsequent input update time, for which stability of the close...
The complexity of evaluating relational queries

A sequence of results which characterize exactly the complexity of problems related to the evaluation of relational queries consisting of projections and natural joins is proved. It is shown that testing whether the result of a given query on a given relation equals some other given relation is D p -complete ( D p is the class of languages that are equal to the intersection of a language in NP and a language in co- NP —it includes both NP and co- NP , and was recently introduced in a totally different context, see Papadimitriou and Yannakakis, 1982 , Proceedings, 14th Annual ACM Sympos. on the Theory of Computing, San Francisco, Calif., pp. 255–260). It is shown that testing inclusion or equivalence of queries with respect to a fixed relation (or of relations with respect to a fixed query) is Π p 2 -complete. The complexity of estimating the number of tuples of the answer is also examined.
Is "ethicist" anything to call a philosopher?

to the discipline. The thing is made the more complicated by the fact that not very much about this discipline is very well understood ? by the general public, by medical folks, by well-meaning academic col? leagues, and even by the more dedicated of its practitioners. The "it," the "field" or "discipline" presents precisely the problem: what in the world is "it"? Expressed in a more usual form: "what in the hell is that philosopher doing in our hospital or medical school?" Or, as my aca? demic friends wonder: "Is 'ethicist' anything to call a philosopher?" I am fully cognizant of the fact that there are some of us who do indeed believe they have a handle on the creature: Robert Veatch has published a book, as you may know, with the audacious and probably presumptuous title, A Theory of Medical Ethics, Tom Beauchamp and James Childress have put another out, Principles of Biom?dical Ethics. Numerous books and anthologies, conferences and symposia, have appeared over the past decade or so, many of which exhibit a phenomenal confidence about the field, its so-called problems, and even appropriate theories and methods by which to deal with them, I confess that all this has me quite baffled, and at times convinced that I have neither the wits nor the intelligence to see things clearly. I have
Flipping triangles and rectangles

We study the chromatic number of the flip graph of triangles determined by n points in convex position in the plane, and present new or improved bounds on several related parameters for this graph. We also find the chromatic numbers of two related graphs: the rectangle flip graph which generalizes the shift graph, and the rolling block graph from the popular puzzle "Rolling Block Maze."
Total Synthesis of (+)‐Myomontanone and (+)‐10,11‐Didehydromyomontanone

The sesquiterpenoid (+)-myomontanone (2), a toxic component of the Australian plant Myoporum montanum, has been synthesized through a short efficient sequence. An electrochemical oxyselenation-deselenation sequence allows oxidation of an intermediate olefin, in the presence of the furan ring, ultimatively providing the requisite enone of the natural product. This approach also allowed synthesis of (+)-10,11-didehydromyomontanone (13) and several other natural products of this family of furanosesquiterpenoids.
A stringy test of the fate of the conifold

Abstract By studying string loop corrections to the superpotential of Type II strings compactified on Calabi-Yau threefolds we find a quantum stringy test and a confirmation of a recent proposal of Strominger on the fate of the conifold singularity. We also propose a connection between the spectrum of Bogomolnyi saturated solitons and the one-loop string partition function of N = 2 topological strings.
Gait phase analysis based on a Hidden Markov Model

Abstract For effective gait rehabilitation treatments, the status of a patient’s gait needs to be analyzed precisely. Since the gait motions are cyclic with several gait phases, the gait motions can be analyzed by gait phases. In this paper, a Hidden Markov Model (HMM) is applied to analyze the gait phases in the gait motions. Smart Shoes are utilized to obtain the ground reaction forces (GRFs) as observed data in the HMM. The posterior probabilities from the HMM are used to infer the gait phases, and the abnormal transition between gait phases are checked by the transition matrix. The proposed gait phase analysis methods have been applied to actual gait data, and the results show that the proposed methods have the potential of tools for diagnosing the status of a patient and evaluating a rehabilitation treatment.
Effect of catalyst structure and carbon deposition on heptane oxidation over supported platinum and palladium

A series of supported platinum and palladium catalysts were tested for heptane oxidation at 75 to 200°C, 20 Torr heptane, 245 Torr oxygen, 795 Torr helium, and conversions below 1%. At these low temperatures, carbon fouls the metal surface. The decline in the turnover frequency with time is accurately fitted with this function: TOFobs = TOFAexp(−kAt) + TOFbexp(−kBt). The turnover frequencies of the A and B sites depend on catalyst structure. At 140°C, the activities of the A sites are: 0.02 s−1 for 50 A platinum crystallites, 0.002 s−1 for 50 A palladium crystallites. The activity of the B sites is 10 times higher on platinum compared to palladium, and is 4 times higher on large crystallites compared to small ones. The amount of carbon on the catalyst depends on the half power of reaction time. These and other results indicate that carbon formed on the metal diffuses slowly to the support. The coke formation and the deactivation rate are much lower on 50 A metal crystallites. On large metal crystallites, the coke formation rate per exposed metal atom and the deactivation rate depend on the number of metal particles on the support and the support composition. Decreasing the number of particles sixfold increases the carbon deposition rate by 2.5 times, and decreases the deactivation rate by 5.3 times. Switching from zirconia (40 m2/g) to alumina (83 m2/g) at 5.0 wt% platinum increases the carbon deposition rate 5 times, and decreases the deactivation rate 5.5 times. Evidently, the faster the carbon migrates from the metal to the support, the slower the carbon fouls the metal surface.
Laser-Induced Neutralization And Negative-Ion Formation In Surface Scattering

In neutralization and negative-ion formation from positive ions scattering from a solid surface, a laser can be used to control the nature of resonant, near-resonant, and even nonresonant transfer of electrons from the conduction band. These spectral characteristics can be achieved by variation of only the laser frequency and intensity.
Interaction rates at high magnetic field strengths and high degeneracy

Abstract In this paper, we have derived the effects of strong magnetic fields B on nucleon and particle reaction rates of astrophysical significance. We have explored the sensitivity to the presence of arbitrary degeneracy and polarization. The possible astrophysical applications of our results are discussed.
The global tracking networks for crustal dynamics

Abstract Highly accurate Satellite Laser Ranging (SLR) and Very-Long-Baseline Interferometry (VLBI) have been implemented by the NASA Crustal Dynamics Project and many cooperating groups in many countries to form global SLR and VLBI networks for geodetic measurements of global plate motion, plate deformation, regional deformations in areas of high earthquake activity, and accurate measurements of the Earth's polar motion and changes in rotation rate. These systems are measuring vector baselines between stations to an accuracy of 2–5 cm. New improvements being implemented will improve the accuracy to about 1 cm.
In-situ hardening hydroxyapatite-based scaffold for bone repair.

Musculoskeletal conditions are becoming a major health concern because of an aging population and sports- and traffic-related injuries. While sintered hydroxyapatite implants require machining, calcium phosphate cement (CPC) bone repair material is moldable, self-hardens in situ, and has excellent osteoconductivity. In the present work, new approaches for developing strong and macroporous scaffolds of CPC were tested. Relationships were determined between scaffold porosity and strength, elastic modulus and fracture toughness. A biocompatible and biodegradable polymer (chitosan) and a water-soluble porogen (mannitol) were incorporated into CPC: Chitosan to make the material stronger, fast-setting and anti-washout; and mannitol to create macropores. Flexural strength, elastic modulus, and fracture toughness were measured as functions of mannitol mass fraction in CPC from 0% to 75%. After mannitol dissolution in a physiological solution, macropores were formed in CPC in the shapes of the original entrapped mannitol crystals, with diameters of 50 μm to 200 μm for cell infiltration and bone ingrowth. The resulting porosity in CPC ranged from 34.4% to 83.3% volume fraction. At 70.2% porosity, the hydroxyapatite scaffold possessed flexural strength (mean ± sd; n = 6) of (2.5 ± 0.2) MPa and elastic modulus of (0.71 ± 0.10) GPa. These values were within the range for sintered porous hydroxyapatite and cancellous bone. Predictive equations were established by regression power-law fitting to the measured data (R2 > 0.98) that described the relationships between scaffold porosity and strength, elastic modulus and fracture toughness. In conclusion, a new graft composition was developed that could be delivered during surgery in the form of a paste to harden in situ in the bone site to form macroporous hydroxyapatite. Compared to conventional CPC without macropores, the increased macroporosity of the new apatite scaffold may help facilitate implant fixation and tissue ingrowth.
Pd(OAc)2-catalyzed domino reactions of 1,2-dihaloarenes and 2-haloaryl arenesulfonates with Grignard reagents: efficient synthesis of substituted fluorenes

Abstract Pd(OAc) 2 -catalyzed domino reactions of 1,2-dihalobenzenes and 2-haloaryl arenesulfonates with hindered Grignard reagents to form substituted fluorenes, which are believed to occur through palladium associated aryne intermediates, are described. Such palladium associated aryne reaction pathway was found to be favored by omitting the use of phosphine and N -heterocyclic carbene ligands for palladium catalysts and with better leaving groups. Our study suggested that Pd(leaving group)X associated arynes should be formed first and the sp 3 C–H activation preferentially occurred at benzylic C–(1°)H bonds. The work described here provides a high yield, one-step access to substituted fluorenes from readily available 1,2-dihalobenzenes and 2-haloaryl arenesulfonates and hindered Grignard reagents, and this substituted fluorene-making method may find applications in the preparation of substituted fluorene-containing molecules including polymers.
Generalizations of the Goulden–Jackson cluster method

We give several modifications of the Goulden–Jackson cluster method for finding generating functions for words avoiding a given set of forbidden words. Our modifications include functions which can take into account various ‘weights’ on words, including single letter probability distributions, double letter (i.e. pairwise) probability distributions, and triple letter probability distributions. We also describe an alternative, recursive approach to finding such generating functions. We describe Maple implementations of the various modifications. The accompanying Maple package is available at the website for this paper.
SATELLITE TEST OF THE EQUIVALENCE PRINCIPLE: OVERVIEW AND PROGRESS

STEP, the Satellite Test of the Equivalence Principle, is reviewed and the current status of the project is discussed. This space-based experiment will test the universality of free fall and is designed to advance the present state of knowledge by over five orders of magnitude. The international STEP collaboration is pursuing a development plan to improve and verify the technology readiness of key systems. We discuss recent advances with an emphasis on accelerometer fabrication and tests. Critical technologies successfully demonstrated in flight by the Gravity Probe B mission also contribute to progress.
Total Synthesis of (−)-Himandrine

We describe the first total synthesis of (−)-himandrine, a member of the class II galbulimima alkaloids. Noteworthy features of this chemistry include a diastereoselective Diels−Alder reaction in the rapid synthesis of the tricycle ABC-ring system in an enantiomerically enriched form, the use of a formal [3+3] annulation strategy to secure the CDE-ring system with complete diastereoselection, and successful implementation of our biogenetically inspired oxidative spirocyclization of an advanced intermediate. The successful and direct late-stage formation of the F-ring in the hexacyclic core of himandrine drew on the power of biogenetic considerations and fully utilized the inherent chemistry of a plausible biosynthetic intermediate.
The impact of age on the ability to perform under pressure: golfers on the PGA tour

This paper is about aging and the ability to perform under pressure on the PGA tour. Performance increases with golfing skill, but may first increase and then decrease with age as experience interacts with changes in physical condition. Similarly, mental fortitude or the ability of a golfer to perform under pressure may first increase and then decrease with age as experience interacts with changes in the ability to concentrate. Net performance on the tour is the result of both physical golfing skill and the ability to perform under pressure. We control for changes in physical skill and focus on the mental side of the game. The role of experience suggests an inverted U shaped relationship between age and mental performance that could vary significantly across golfers. We use Order-m FDH to calculate a measure of performance under pressure, and we confirm an inverted U-shaped curve with age. Along the way, we examine the ability to perform under pressure at the level of the individual golfer.
Effect of Heat on Space-Time Correlations in Jets

Measurements of space-time correlations of velocity, acquired in jets from acoustic Mach number 0.5 to 1.5 and static temperature ratios up to 2.7 are presented and analyzed. Previous reports of these experiments concentrated on the experimental technique and on validating the data. In the present paper the dataset is analyzed to address the question of how space-time correlations of velocity are different in cold and hot jets. The analysis shows that turbulent kinetic energy intensities, lengthscales, and timescales are impacted by the addition of heat, but by relatively small amounts. This contradicts the models and assumptions of recent aeroacoustic theory trying to predict the noise of hot jets. Once the change in jet potential core length has been factored out, most one- and two-point statistics collapse for all hot and cold jets.
Aromatic cation activation of alcohols: conversion to alkyl chlorides using dichlorodiphenylcyclopropene.

A novel paradigm for the activation of alcohols toward nucleophilic displacement via formation of cyclopropenium ethers is described. The conversion of a range of alcohol substrates to the corresponding alkyl chlorides occurs rapidly upon treatment with 3,3-dichloro-1,2-diphenylcyclopropene. 1H NMR data support the intermediacy of a cyclopropenium intermediate, and the reaction is demonstrated to proceed primarily via the SN2 mechanism for 1-phenylethanol. A total of 12 examples of substrate scope are provided.
Hypertext and Web engineering

We take a two-stage approach to engineering World Wide Web applications. First a Relationship-Navigation Analysis, analyzes an existing or new application specifically in terms of its intraand inter-relationships. Second, a dynamic hypermedia engine (DHymE), automatically generates links for each relationship and metaknowledge items at run-time. Links and navigation supplement the application’s primary functionality.
Large-scale vectorized implicit calculations in solid mechanics on a Cray X-MP/48 utilizing EBE preconditioned conjugate gradients

Abstract The major costs of large implicit finite element calculations, particularly in three dimensions, arise from computing solutions to systems of linear equations. Direct methods, i.e., those based upon Gaussian elimination, can easily require prohibitively large amounts of both CPU time and storage, even on current supercomputers. Iterative procedures avoiding the formation and factorization of a global system of equations can circumvent these difficulties. The element-by-element (EBE) preconditioned conjugate gradients (PCG) algorithm is presented in the context of a vectorized implementation within the production nonlinear stress analysis code nike 3 d . Due to continued confusion as to the ease of vectorizing finite element procedures, we include examples of the main EBE subroutines in their entirety. The concept of a fractal dimension of a finite element mesh is introduced, and proves useful in characterizing the efficiency of this iterative algorithm with respect to a variable band, active column direct method. Sample calculations on a Cray X-MP/48 with solid-state storage device (SSD) illustrate the economy and range of applicability of EBE/PCG. Asymptotic cost formulae derived for two linear problems underscore differences between the direct and iterative algorithms for large problems and lead to predictions of problem size limitations imposed by the computing environment.
A Chronic Inhalation Toxicity Study of Diesel Engine Emissions and Coal Dust, Alone and Combined:

To evaluate the potential health hazards of diesel engine emissions in underground coal mines, inhalation studies were performed using three species of animals. A wide range of toxicological responses was measured. Exhaust was provided by a 425 in.3 displacement four-cycle, water-cooled, naturally aspirated diesel engine (Caterpillar Model 3304) equipped with a water scrubber. Exposures were 7 h/day, 5 days/week, for periods up to 24 months. Micronized coal dust was generated using a Wright dust feeder. Four exposures were evaluated: (1) filtered ambient air, (2) 2 mg/m3 diesel particulate, (3) 2 mg/m3 respirable coal dust, and (4) 1 mg/m3 each of 2 and 3. Gaseous and vapor concentrations were similar in both exposures employing diesel exhaust. Male cynomolgus monkeys, Fischer-344 male and female rats, and female CD-1 mice were the experimental subjects. Monkeys were sacrificed at 24 months, rats at 3, 6, 12, and 24 months, and mice at 1, 3, and 6 months.Gross morphology and histopathology demonstrated th...
Order and disorder in AKLT antiferromagnets in three dimensions

The models constructed by Affleck, Kennedy, Lieb, and Tasaki (AKLT) [Phys. Rev. Lett. 59, 799 (1987)] describe a family of quantum antiferromagnets on arbitrary lattices, where the local spin $S$ is an integer multiple $M$ of half the lattice coordination number. The equal-time quantum correlations in their ground states may be computed as finite temperature correlations of a classical $O(3)$ model on the same lattice, where the temperature is given by $T=1/M$. In dimensions $d=1$ and 2 this mapping implies that all AKLT states are quantum disordered. We consider AKLT states in $d=3$ where the nature of the AKLT states is now a question of detail depending upon the choice of lattice and spin; for sufficiently large $S$ some form of N\'eel order is almost inevitable. On the unfrustrated cubic lattice, we find that all AKLT states are ordered, while for the unfrustrated diamond lattice the minimal $S=2$ state is disordered while all other states are ordered. On the frustrated pyrochlore lattice, we find (conservatively) that several states starting with the minimal $S=3$ state are disordered. The disordered AKLT models we report here are a significant addition to the catalog of magnetic Hamiltonians in $d=3$ with ground states known to lack order on account of strong quantum fluctuations.
(-)-SANDRAMYCIN : TOTAL SYNTHESIS AND CHARACTERIZATION OF DNA BINDING PROPERTIES

Full details of the total synthesis of the potent antitumor antibiotic (−)-sandramycin (1), a cyclic decadepsipeptide possessing a 2-fold axis of symmetry, is described and constitutes the first total synthesis of a member of the growing class of naturally occurring agents now including the luzopeptins and quinaldopeptin. Key strategic elements of the approach include the late stage introduction of the heteroaromatic chromophore thereby providing access to analogs possessing altered intercalation capabilities, symmetrical pentadepsipeptide coupling and 32-membered macrocyclization conducted at the single secondary amide site in superb conversion (90%), and a convergent assemblage of the precursor pentadepsipeptide in which the potentially labile ester linkage was introduced in the final key coupling reaction. This approach also provided the cyclic decadepsipeptides 24−26 lacking both chromophores and was extended to provide 32 lacking one of the two chromophores. The characterization of the DNA-binding pr...
Efficient synthesis of 2'-C-α-aminomethyl-2'-deoxynucleosides.

Starting from methyl 3,5-di-O-benzyl-2-keto-α-D-ribofuranoside, a convergent, six-step synthesis is developed to give efficiently all four 2′-C-α-aminomethyl-2′-deoxynucleosides (U, C, A, G) in 38%, 42%, 12%, 12% yield, respectively. Convergence is achieved by the glycosylation of persilylated nucleobases with methyl 2-α-phthalimidomethyl ribofuranoside.
The impact of passive investing on corporate valuations

Purpose – The purpose of this paper is to explore the impact of S&P 500 index fund money flow on the valuations of companies that are constituents of the index and those that are not.Design/methodology/approach – To examine the impact of passive investing on corporate valuations, the authors run panel regressions of price‐to‐earnings ratio on aggregate money flow into S&P 500 index funds and control for various accounting variables that impact price‐to‐earnings ratio. These regressions involve two samples of stocks. The first sample consists of S&P 500 constituents. The second consists of large‐cap stocks that are not constituents of the S&P 500. The authors also run a set of separate regressions with price‐to‐book ratio rather than price‐to‐earnings ratio as the dependent variable.Findings – It is found that the valuations of S&P 500 constituents increased by 139 to 167 basis points relative to nonconstituents, depending on valuation metric, due to S&P 500 index fund money flow when evaluated at mean val...
Longitudinal LASSO: Jointly Learning Features and Temporal Contingency for Outcome Prediction

Longitudinal analysis is important in many disciplines, such as the study of behavioral transitions in social science. Only very recently, feature selection has drawn adequate attention in the context of longitudinal modeling. Standard techniques, such as generalized estimating equations, have been modified to select features by imposing sparsity-inducing regularizers. However, they do not explicitly model how a dependent variable relies on features measured at proximal time points. Recent graphical Granger modeling can select features in lagged time points but ignores the temporal correlations within an individual's repeated measurements. We propose an approach to automatically and simultaneously determine both the relevant features and the relevant temporal points that impact the current outcome of the dependent variable. Meanwhile, the proposed model takes into account the non-i.i.d nature of the data by estimating the within-individual correlations. This approach decomposes model parameters into a summation of two components and imposes separate block-wise LASSO penalties to each component when building a linear model in terms of the past τ measurements of features. One component is used to select features whereas the other is used to select temporal contingent points. An accelerated gradient descent algorithm is developed to efficiently solve the related optimization problem with detailed convergence analysis and asymptotic analysis. Computational results on both synthetic and real world problems demonstrate the superior performance of the proposed approach over existing techniques.
Computation of Delta-Wing Roll Maneuvers

This article presents computations of delta-wing roll maneuvers for an 80-deg sweep delta-wing at 30-deg angle of attack. Three constant roll-rate maneuvers are considered. Two of the maneuvers consist of a roll from 0 to 45 deg at nondimensiona l roll rates of = 0.0233 and 0.0467. The third roll maneuver computed starts at a 45-deg roll angle and rolls back to a -45-deg roll angle at a roll rate 4> = -0.0467. The governing equations are the unsteady, three-dimensional Navier-Stokes equations. The equations are solved using the implicit, approximately-factored, diagonal form of the Beam-Warming algorithm. Subiterations are used to provide a more accurate means of implementing the diagonal form of the algorithm for unsteady flows. The effects of roll-rate and differing initial roll angles on the dynamical behavior of the vortices positions and strengths as well as their corresponding effect on surface pressure and roll moment coefficient are described.
The dark top

We present a class of composite Higgs models in which the particle that regulates the top quark contribution to the Higgs potential is also a weakly-interacting dark matter candidate. This color-neutral ``dark top'' is related to the standard model top quark through a large global symmetry. Because the same couplings that control the Higgs potential also determine various dark matter cross sections, the dark top scenario is quite predictive once the dark top mass and various quantum numbers are specified. We construct two concrete examples of dark top models with plausible UV completions and study their dark matter properties and LHC signatures.