cssi/SciSciGPT-SciSciNet huggingface dataset:
Risk Management in the Cooperative Contract

Agricultural cooperatives have long played an important role in helping their members manage risk. Yet the typical cooperative (co-op) does a much better job of helping its members manage some sorts of risk than it does others. In particular, co-ops are good at helping members manage marketing risk, or idiosyncratic variation in prices observed within the course of a single season. However, agricultural cooperatives seem not to be particularly good at helping their members to manage production risk, which involves variation in yield over the course of several years. This paper argues that by taking advantage of the multi-year nature of most members’ relationship with the cooperative, the cooperative can also provide a useful (though limited) form of insurance against crop shortfalls. Agricultural producers face various sorts of risk; some of these are difficult to manage using standard institutions. Agricultural cooperatives can play an important role in helping their members to manage these sources of risk. For example, marketing co-ops traditionally help to reduce price risk by pooling sales across time and space, and could reduce production risk by making some payments to members on the basis of predetermined shares, rather than on actual delivery or “patronage.” However, just because a cooperative can help its members manage risk does not mean that membership in a cooperative will serve as a useful means for dealing with risk. The details of a cooperative’s by-laws, management of equity, mechanisms governing the transfer of delivery rights, methods of capitalization, pooling rules, and expansion options can all have a big impact on the usefulness of the cooperative structure as a risk-management tool for users. Here, we provide an enumeration of some different sorts of shocks which may be important to agricultural producers and then describe the manner in which a typical cooperative market pooling mechanism
The effects of government, academic and industrial policy on cross-university collaboration

This article examines how collaborating with industry influences the academic scientist's collaborations with scientists at other universities (cross-university collaboration). Government policies have actively encouraged academics in different universities to collaborate with one another, but contract requirements stemming from academic-industrial collaborations often influence the ways in which academics can collaborate. The major findings from this article show that collaborating with industry appears to be linked to increasing levels of cross-university collaboration. Copyright , Beech Tree Publishing.
Extreme Value Distributions for some classes of Non-Uniformly Partially Hyperbolic Dynamical Systems

In this note, we obtain verifiable sufficient conditions for the extreme-value distribution for a certain class of skew-product extensions of non-uniformly hyperbolic base maps. We show that these conditions, formulated in terms of the decay of correlations on the product system and the measure of rapidly returning points on the base, lead to a distribution for the maximum of Φ(p)=−log(d(p,p0)) that is of the first type. In particular, we establish the type I distribution for S1 extensions of piecewise C2 uniformly expanding maps of the interval, non-uniformly expanding maps of the interval modeled by a Young tower, and a skew-product extension of a uniformly expanding map with a curve of neutral points.
Homicide trials in Classical Athens

Homicide trials in Classical Athens had a unique feature. After the initial evidence was presented the defendant was given the option to go into a self-imposed exile for life losing all protections, rights, and wealth. If the defendant did not go into exile, then the trial continued with additional arguments presented. If the judges voted to convict, the sanction of death was imposed. Given the limited set of feasible sanctions available to the Athenians, it is argued that this institution is effective as it separates some guilty from the innocent. Consequently, fewer innocent are convicted and more guilty are punished.
Integrated Antimicrobial and Nonfouling Zwitterionic Polymers

Zwitterionic polymers are generally viewed as a new class of nonfouling materials. Unlike their poly(ethylene glycol) (PEG) counterparts, zwitterionic polymers have a broader chemical diversity and greater freedom for molecular design. In this Minireview, we highlight recent microbiological applications of zwitterionic polymers and their derivatives, with an emphasis on several unique molecular strategies to integrate antimicrobial and nonfouling properties. We will also discuss our insights into the bacterial nonfouling performance of zwitterionic polymers and one example of engineering zwitterionic polymer derivatives for antimicrobial wound-dressing applications.
Nuclear symmetry energy: An experimental overview

The nuclear symmetry energy is a fundamental quantity important for studying the structure of systems as diverse as the atomic nucleus and the neutron star. Considerable efforts are being made to experimentally extract the symmetry energy and its dependence on nuclear density and temperature. In this article, the experimental studies carried out up-to-date and their current status are reviewed.
Material Characteristics of Spin‐On Glasses for Interlayer Dielectric Applications

On etudie les proprietes de divers verres commerciaux deposes par centrifugation pour ameliorer la planeite. La spectrophotometrie infrarouge permet d'etudier les effets du recuit sur la concentration des groupes hydroxyle et groupes organiques. Ces concentrations sont sensibles aux temperatures de recuit et aux milieux ambiants pendant le recuit. On controle a la fois la contrainte a temperature ambiante et la contrainte in situ. Les niveaux de contrainte mesures sur des couches deposees sur silicium sont faibles (moins de 10 8 Pa en traction) par comparaison aux autres couches de dioxyde de silicium. Une forte correlation entre les proprietes dielectriques (constantes dielectriques et facteurs de dissipation) et la teneur en OH est observee. Sur deux couches etudiees plus particulierement, l'une avait des proprietes dielectriques nettement meilleures apres recuit a basse temperature (<600°C). Toutes deux etaient de bonnes couches dielectriques comme couches de transition dans les circuits VLSI apres recuit a haute temperature
Enumeration of genus-three plane curves with a fixed complex structure

We give a practical formula for counting irreducible nodal genus-three plane curves with a fixed general complex structure on the normalization. As an intermediate step, we enumerate rational plane curves that have a (3, 4)-cusp.
Dipole interactions and electrical polarity in nanosystems: The Clausius–Mossotti and related models

Point polarizable molecules at fixed spatial positions have solvable electrostatic properties in classical approximation, the most familiar being the Clausius-Mossotti (CM) formula. This paper generalizes the model and imagines various applications to nanosystems. The behavior is worked out for a sequence of octahedral fragments of simple cubic crystals, and the crossover to the bulk CM law is found. Some relations to fixed moment systems are discussed and exploited. The one-dimensional dipole stack is introduced as an important model system. The energy of interaction of parallel stacks is worked out, and clarifies the diverse behavior found in different crystal structures. It also suggests patterns of self-organization which polar molecules in solution might adopt. A sum rule on the stack interaction is found and tested. Stability of polarized states under thermal fluctuations is discussed, using the one-dimensional domain wall as an example. Possible structures for polar hard ellipsoids are considered. An idea is formulated for enhancing polarity of nanosystems by intentionally adding metallic coatings.
Plasma etching - a discussion of mechanisms

Abstract Plasma etching, which is expected to play an important role in the manufacture of semiconductor and other devices requiring fine–line lithography, involves using a glow discharge to generate chemically reactive species from relatively inert molecular gases.1 These reactive species combine chemically with certain solid materials to form volatile compounds which are removed by the vacuum pumping system. Although the general concept is relatively simple, the complexities of the glow discharge itself and of the associated parameter space have impeded the development of a detailed understanding of the chemical reactions involved in the process, which in turn has impeded the implementation of plasma etching in device manufacture.
Studies on the dolabellanes: Stereoselective transannular cyclizations of dolabelladiene macrocycles

Abstract Eleven-membered dolabelladiene carbocycles have been transformed into several tricyclic ring systems via efficient, stereocontrolled, transannular olefin-enone cyclizations. Ring contractions of the [9.3.0]cyclotetradecane.nucleus have provided 5-7-6 dolastane and 5-8-5 fusicoccane carbocycles.
DBI inflation in the tip region of a warped throat

Previous work on DBI inflation, which achieves inflation through the motion of a D3 brane as it moves through a warped throat compactification, has focused on the region far from the tip of the throat. Since reheating and other observable effects typically occur near the tip, a more detailed study of this region is required. To investigate these effects we consider a generalized warp throat where the warp factor becomes nearly constant near the tip. We find that it is possible to obtain 60 or more e-folds in the constant region, however large non-gaussianities are typically produced due to the small sound speed of fluctuations. For a particular well-studied throat, the Klebanov-Strassler solution, we find that inflation near the tip may be generic and it is difficult to satisfy current bounds on non-gaussianity, but other throat solutions may evade these difficulties.
Progressive multiple alignment with constraints

A progressive alignment algorithm produces a multi-alignment of a set of sequences by repeatedly aligning pairs of sequences and/or previously generated alignments. We describe a method for guaranteeing that the alignment generated by a progressive alignment strategy satisfies a user-specified collection of constraints about where certain sequence positions should appear relative to others. Given a collection of constraints over sequences whose total length is , our algorithm takes time. An alignment of the -like globin gene clusters of several mammals illustrates t he practicality of the method.
Banana or fruit? Detection and recognition across categorical levels in RSVP

Pictured objects and scenes can be understood in a brief glimpse, but there is a debate about whether they are first encoded at the basic level (e.g., banana), as proposed by Rosch et al. (1976, Cognitive Psychology) , or at a superordinate level (e.g., fruit). The level at which we first categorize an object matters in everyday situations because it determines whether we approach, avoid, or ignore the object. In the present study, we limited stimulus duration in order to explore the earliest level of object understanding. Target objects were presented among five other pictures using RSVP at 80, 53, 27, or 13 ms/picture. On each trial, participants viewed or heard 1 of 28 superordinate names or a corresponding basic-level name of the target. The name appeared before or after the picture sequence. Detection (as d') improved as duration increased but was significantly above chance in all conditions and for all durations. When the name was given before the sequence, d' was higher for the basic than for the superordinate name, showing that specific advance information facilitated visual encoding. In the name-after group, performance on the two category levels did not differ significantly; this suggests that encoding had occurred at the basic level during presentation, allowing the superordinate category to be inferred. We interpret the results as being consistent with the claim that the basic level is usually the entry level for object perception.
Properties of Galactic Outflows: Measurements of the Feedback from Star Formation

Properties of starburst-driven outflows in dwarf galaxies are compared with those in more massive galaxies. Over a factor of ~10 in galactic rotation speed, supershells are shown to lift warm ionized gas out of the disk at rates up to several times the star formation rate. The amount of mass escaping the galactic potential, in contrast to the disk, does depend on the galactic mass. The temperature of the hottest extended X-ray emission shows little variation around ~106.7 K, and this gas has enough energy to escape from the galaxies with rotation speed less than approximately 130 km s-1.
Evidence for d orbital aromaticity in square planar coinage metal clusters.

Quantitative evidence for the existence of aromaticity involving the d orbitals of transition metals is provided for the first time. The doubly bridged square planar (D4h) coinage metal clusters (M4Li2, M = Cu (1), Ag (2), and Au (3)) are characterized as aromatic by their substantial nucleus independent chemical shifts (NICS) values in the centers (−14.5, −14.1, and −18.6, respectively). Nevertheless, the participation of p orbitals in the bonding (and cyclic electron delocalization) of 1−3 is negligible. Instead, these clusters benefit strongly from the delocalization of d and to some extent s orbitals. The same conclusion applies to Tsipis and Tsipis' H-bridged D4h Cu4H4 ring (4). Canonical MO−NICS analysis of structures 1−3 shows the total diatropic d orbital contributions to the total NICS to be substantial, although the individual contributions of the five sets of filled d orbitals vary. The d orbital aromaticity of Cu4Li2 also is indicated by its atomization energy, 243.2 kcal/mol, which is larger ...
A global solution curve for a class of periodic problems, including the relativistic pendulum

AbstractUsing continuation methods, we study the global solution structure of periodic solutions for a class of periodically forced equations, generalizing the case of relativistic pendulum. We obtain results on the existence and multiplicity of periodic solutions. Our approach is suitable for numerical computations, and in fact we present some numerically computed bifurcation diagrams illustrating our results.
Modeling and analysis of calcium bromide hydrolysis

Abstract The main focus of this paper is the modeling, simulation, and analysis of the calcium bromide hydrolysis reactor stage in the calcium–bromine thermochemical water-splitting cycle for nuclear hydrogen production. One reactor concept is to use a spray of calcium bromide into steam, in which the heat of fusion supplies the heat of reaction. Droplet models were built up in a series of steps incorporating various physical phenomena, including droplet flow, heat transfer, phase change, and reaction, separately. Given the large heat reservoir contained in a pool of molten calcium bromide that allows bubbles to rise easily, using a bubble column reactor for the hydrolysis appears to be a feasible and promising alternative to the spray reactor concept. The two limiting cases of bubble geometry, spherical and spherical-cap, are considered in the modeling. Results for both droplet and bubble modeling with COMSOL MULTIPHYSICS™ are presented, with recommendations for the path forward.
An efficient cyclopentenone formation via an allene oxide

A new and efficient cyclopentenone annulation reaction has been developed. The annulation involves the in situ epoxidation [tBuOOH, VO(acac)2] of vinyl allenes 1a-f to furnish cyclopentenones 2a-f in 40~70% yield. This reaction closely resembles the proposed biosynthetic route to prostanoids.
Optimization Among Provably Equivalent Programs

We consider the extent to which it's possible, given 8 program p for computing a function, f, to Find an optimal program p' which also computes f and is either provably equivalent to p or else provably an optimal program. Our methods and problems come chiefly from abstract recurslontheoretic complexity theory, but some of our results may be viewed as directly challenging the intuitive interpretatIon of earlier results In the area.
A Behavioral Theory of Corporate Governance: Explicating the Mechanisms of Socially Situated and Socially Constituted Agency

We propose a behavioral theory of corporate governance based on an ontological foundation of socially situated and socially constituted agency. More specifically, we advance a multi-level, mechanism-based, theory of governance that is socially informed yet actor-centric, and thus offers a distinct alternative to under-socialized governance theories, such as agency theory. We highlight the contributions of recent governance research in providing the foundation for such a behavioral theory, with particular emphasis on our prior work that demonstrated the relevance of social structural relationships, institutional processes, and social cognition. We conclude with a discussion of the central themes that emerge from our perspective.
Exact inequalities for sums of asymmetric random variables, with applications

Let \({{\rm BS}_{1},\dots,{\rm BS}_{n}}\) be independent identically distributed random variables each having the standardized Bernoulli distribution with parameter \({p \in (0, 1)}\) . Let \({m_*(p):=(1 + p + 2 p^{2})/(2\sqrt{p - p^{2}} + 4 p^{2})}\) if \({0 < p \le \frac12}\) and \({m_{*}(p) := 1 if \frac12 \le p < 1}\) . Let \({m \ge m_{*}(p)}\) . Let f be such a function that f and f′′ are nondecreasing and convex. Then it is proved that for all nonnegative numbers \({c_{1},\dots,c_{n}}\) one has the inequality \({{\mathsf{E}} f(c_1{\mathrm{B\!S}}_1+\dots+c_n{\mathrm{B\!S}}_n)\le{\mathsf{E}} f\big(s^{(m)}({\mathrm{B\!S}}_1+\dots+{\mathrm{BS}}_{n})\big),}\) where \({s^{(m)}:=\big(\frac1n\,\sum_{i=1}^n c_i^{2m}\big)^\frac1{2m}}\) . The lower bound \({m_{*}(p)}\) on m is exact for each \({p \in (0,1)}\) . Moreover, \({{\operatorname{\mathsf{E}}} f(c_1{\mathrm{B\!S}}_1+\dots+c_n{\mathrm{B\!S}}_n)}\) is Schur-concave in \({(c_{1}^{2m},\ldots,c_{n}^{2m})}\) .
Total Synthesis of Syringolin A

A convergent, efficient synthesis of syringolin A has been accomplished in 13 steps from commercially available materials, Garner’s aldehyde and l-valine. The unnatural 3,4-dehydrolysine fragment was prepared using successive Johnson−Claisen/Curtius rearrangement reactions. The macrolactamization and late-stage introduction of the side chain will provide convenient access to analogues of this promising proteasome inhibitor.
Photoproducts from the photolysis of tris(bipyridine)ruthenium(II) chloride in dimethylformamide

Abstract Six photoproducts were observed in the photolysis of [Ru(bpy) 3 ] 2+ in N,N -dimethylformamide (DMF) in the presence of chloride ions. The primary products were cis -[Ru(bpy) 2 Cl 2 ] and cis -[Ru(bpy) 2 -(DMF)Cl] + . The remaining ruthenium products, which were thermally unstable to varying degrees, were cis -[Ru(bpy) 2 Cl 2 ] + , [Ru(bpy) 3 ] + , and a binuclear species we have tentatively identified as [Ru(bpy) 2 Cl] 2 n+ ( n = 3 or 4).
New enone derivatives of oleanolic acid and ursolic acid as inhibitors of nitric oxide production in mouse macrophages

Abstract New derivatives of 3-oxoolean-1-en-28-oic acid and 3-oxours-1-en-28-oic acid were synthesized. Nine of them showed significant inhibitory activity against interferon-γ-induced nitric oxide production in mouse macrophages when assayed at the 1 μM level. 3,12-Dioxoolean-1,9-dien-28-oic acid ( 3 ) had the highest activity (IC 50 , 0.9 μM).
Vector bundles and lax equations on algebraic curves

The Hamiltonian theory of zero-curvature equations with spectral parameter on an arbitrary compact Riemann surface is constructed. It is shown that the equations can be seen as commuting flows of an infinite-dimensional field generalization of the Hitchin system. The field analog of the elliptic Calogero-Moser system is proposed. An explicit parameterization of Hitchin system based on the Tyurin parameters for stable holomorphic vector bundles on algebraic curves is obtained.
ALMA North American Integration Center Front-End Test System

The Atacama Large Millimeter/submillimeter (ALMA) Array Front End (FE) system is the first element in a complex chain of signal receiving, conversion, processing and recording. 70 Front Ends will be required for the project. The Front End is designed to receive signals in ten different frequency bands. In the initial phase of operations, the antennas will be fully equipped with six bands. These are Band 3 (84–116 GHz), Band 4 (125–163 GHz), Band 6 (211–275 GHz), Band 7 (275–373 GHz), Band 8 (385–500 GHz) and Band 9 (602–720 GHz). It is planned to equip the antennas with the missing bands at a later stage of ALMA operations, with a few Band 5 (163–211 GHz) and Band 10 (787–950 GHz) receivers in use before the end of the construction project. The ALMA Front End is far superior to any existing receiver systems; spin-offs of the ALMA prototypes are leading to improved sensitivities in existing millimeter and submillimeter observatories. The Front End units are comprised of numerous elements, produced at different locations in Europe, North America and East Asia and are integrated at several Front End integration centers (FEIC) to insure timely delivery of all the units to Chile. The North American FEIC (NA FEIC) is at the National Radio Astronomy Observatory facility in Charlottesville, Virginia, USA. This paper describes the design and performance of the test set used at the NA FEIC to check the performance of the Front Ends, following integration and prior to shipment to Chile.
The Effect of Incentives on Knowledge Sharing in Computer‐Mediated Communication: An Experimental Investigation

Do financial incentives increase knowledge sharing in a computermediated environment? Thirty‐six accounting students assigned to groups with different financial incentives (group, piece‐rate, or tournament) searched for errors in accounting‐related spreadsheets, with access to an online chat room they could use for helping others. The dependent variable was the amount of knowledge the students shared with others. Quantitative and qualitative data suggest that the group financial incentives inspired more knowledge sharing than did either tournament or piece‐rate. Results suggest that managers should carefully consider incentive structures in computer‐based systems because incentives potentially affect knowledge sharing.
Estimating Network Economies in Retail Chains: A Revealed Preference Approach

Many industries are characterized by a small number of rms making many entry decisions over a large choice set. Nowhere is this more true than in the case of the discount retail sector, where Target, Wal-Mart, and Kmart compete in a national market. Traditional discrete choice models of rm entry are ill-suited to this high dimensional choice problem. We instead draw upon recent innovations in the application of maximum score estimators to models of revealed preference (Bajari and Fox (2006), Fox (2007)). Unlike previous work on this sector, our approach allows us to consider any number of potential rivals, any number of stores per location, the endogeneity of the distribution network, and unobserved (to the econometrician) location attributes that might cause rms to cluster their stores. Moreover, we show how recent innovations in set identication and inference can be used to separate the role of these unobservables from observed location attributes like population. We nd that all
Management of allergic aspergillosis

Treatment of allergic bronchopulmonary aspergillosis depends on accurate diagnosis, which is difficult because of multiple clinical, radiographic, and immunologic criteria; unstandardized immunoassays; and its similarity to cystic fibrosis. Advances in chest CT interpretation, measuring serum Aspergillus fumigatus-specific antibodies and the TH2 chemokine thymusactivated-and-regulated chemokine, recognizing risk factors, should improve diagnostic accuracy. Oral glucocorticosteroids remain the mainstay of treatment. Dose regimen and duration are not standardized, so expert recommendations are used. Inhaled steroids have not been proven to be effective. Due to relapse and toxicity, itraconazole has been added as second-tier therapy, supported by randomized, placebo-controlled trials in asthma and open-label trials in cystic fibrosis. Itraconazole is steroid sparing with anti-inflammatory aspects and poor bioavailability. Despite combination steroid-itraconazole therapy, relapses and steroid toxicity have led to open-label use of voriconazole, nebulized amphotericin B, monthly high-dose intravenous methylprednisolone, and omalizumab. Controlled trials are needed to evaluate these and other antifungal or immunomodulatory interventions.
On the Hardness of Signaling

There has been a recent surge of interest in the role of information in strategic interactions. Much of this work seeks to understand how the realized equilibrium of a game is influenced by uncertainty in the environment and the information available to players in the game. Lurking beneath this literature is a fundamental, yet largely unexplored, algorithmic question: how should a "market maker" who is privy to additional information, and equipped with a specified objective, inform the players in the game? This is an informational analogue of the mechanism design question, and views the information structure of a game as a mathematical object to be designed, rather than an exogenous variable. We initiate a complexity-theoretic examination of the design of optimal information structures in general Bayesian games, a task often referred to as signaling. We focus on one of the simplest instantiations of the signaling question: Bayesian zero-sum games, and a principal who must choose an information structure maximizing the equilibrium payoff of one of the players. In this setting, we show that optimal signaling is computationally intractable, and in some cases hard to approximate, assuming that it is hard to recover a planted clique from an Erdos-Renyi random graph. This is despite the fact that equilibria in these games are computable in polynomial time, and therefore suggests that the hardness of optimal signaling is a distinct phenomenon from the hardness of equilibrium computation. Necessitated by the non-local nature of information structures, en-route to our results we prove an "amplification lemma" for the planted clique problem which may be of independent interest. Specifically, we show that even if we plant many cliques in an Erdos-Renyi random graph, so much so that most nodes in the graph are in some planted clique, recovering a constant fraction of the planted cliques is no easier than the traditional planted clique problem.
The Extracellular Matrix: Not Just Pretty Fibrils

The extracellular matrix (ECM) and ECM proteins are important in phenomena as diverse as developmental patterning, stem cell niches, cancer, and genetic diseases. The ECM has many effects beyond providing structural support. ECM proteins typically include multiple, independently folded domains whose sequences and arrangement are highly conserved. Some of these domains bind adhesion receptors such as integrins that mediate cell-matrix adhesion and also transduce signals into cells. However, ECM proteins also bind soluble growth factors and regulate their distribution, activation, and presentation to cells. As organized, solid-phase ligands, ECM proteins can integrate complex, multivalent signals to cells in a spatially patterned and regulated fashion. These properties need to be incorporated into considerations of the functions of the ECM.
Review of electron neutrino appearance oscillation experiments

A review of νe appearance oscillation experiments is presented. The measurement of the appearance signal is of particular interest because this mode is sensitive to both θ13, δCP and other mixing parameters. Using the value of θ13 measured by reactor neutrino experiments (disappearance studies) present and next generation appearance experiments can explore CP violation.
On Passive Damping Mechanisms in Large Space Structures

The significance is explained of even tiny amounts of passive energy dissipation to ensure successful stabilization of large, flexible space structures. Study of scale effects on various mechanisms indicates that modal damping ratios are likely to decrease as size increases in a family of similar structures. Paper focuses on thermal dissipation induced by strain gradients during vibration of monolithic configurations. Past work and the expected magnitudes of this damping are reviewed, along with reasons why it is, to some degree, under the designer's control. In the search for the highest practical values, unidirectional metallic composites and other arrangements are examined
Probing Disk Accretion in Young Brown Dwarfs

We present high-resolution optical spectra of 15 objects near or below the substellar limit in the Upper Scorpius and ρ Ophiuchus star-forming regions. These spectra, obtained with the High Resolution Echelle Spectrometer on the Keck I telescope, are used to investigate disk accretion, rotation, and activity in young very low mass objects. We report the detection of a broad, asymmetric Hα emission line in the ρ Oph source GY 5, which is also known to harbor mid-infrared excess, consistent with the presence of an accreting disk. The Hα profiles of the Upper Sco objects suggest little or no ongoing accretion. Our results imply that if most brown dwarfs are born with disks, their accretion rates decrease rapidly, at timescales comparable to or smaller than those for T Tauri disks. The Upper Sco brown dwarfs appear to be rotating faster than their somewhat younger counterparts in Taurus, consistent with spin-up due to contraction following disk unlocking. The Hα activity is comparable to saturated activity levels in field M dwarfs with similar spectral type and rotation rates. Comparison of our data with published (albeit lower resolution) spectra of a few of the same objects from other epochs suggests possible variability in accretion/activity indicators.
Strategic alliance via co-opetition: Supply chain partnership with a competitor

Why do two competitors form an alliance yet still compete with each other in the marketplace? Consider Yahoo's recent alliance with Microsoft to use its Bing search engine, yet both companies will compete with each other to sell search ads. In this paper we study dynamic alliance formation among competing firms with a multi-period model. In each period, there is a two-stage game of co-opetition. In Stage 1, two competing firms decide on forming a partnership by negotiating a contractual agreement; and in Stage 2, all firms in the market engage in price competition. We formulate the economic incentives and costs of the cooperation, propose the optimal contract and discuss the reasons for a temporary co-opetition and a delayed co-opetition. The results of the paper shed light on firms' strategic decision on co-opetition and provide implications to public policy makers.
Alternative synthesis and thermal atropisomerism of a fully functionalized DEFG ring system of teicoplanin

Abstract An alternative synthesis and the thermal atropisomerism of a fully functionalized DEFG ring system of teicoplanin are described.
Helical micro-drill point design and grinding

A new drill point geometry, termed the helical drill point, specifically intended for micro-drills, is developed in order to alleviate the disadvantages of existing planar micro-drill points. A mathematical model for this new drill point has been established. It is shown that this model is more general than existing drill point models. The commonly used conical, cylindrical and planar drill point models are only special cases of the helical model. For uniquely determining the grinding parameters of the new drill point as well as guiding the grinder design, the characteristics, the controllability and the sensitivity of the grinding parameters have been analyzed. Finally the geometric characteristics of this new drill point are investigated.
The Effect of Tolerance to Noninherited Maternal HLA Antigens on the Survival of Renal Transplants from Sibling Donors

Background During pregnancy and nursing, a baby's developing immune system is intimately exposed to the mother's antigens. To determine whether this exposure is of clinical benefit to patients who later receive an allograft as an adult, we analyzed the outcome of primary renal transplantations from sibling donors. Methods We retrospectively studied graft survival and rejection episodes in 205 patients who had received renal transplants at nine centers between 1966 and 1996 from sibling donors bearing maternal or paternal HLA antigens not inherited by the recipient. The sibling donors were categorized by analysis of family HLA-typing data. Results In the multicenter analysis, graft survival was higher 5 years and 10 years after transplantation in recipients of kidneys from siblings expressing maternal HLA antigens not inherited by the recipient than in recipients of kidneys from siblings expressing paternal HLA antigens not inherited by the recipient (86 percent vs. 67 percent at 5 years and 77 percent vs....
Complex multiplication symmetry of black hole attractors

Abstract We show how Moore's observation, in the context of toroidal compactifications in type IIB string theory, concerning the complex multiplication structure of black hole attractor varieties, can be generalized to Calabi–Yau compactifications with finite fundamental groups. This generalization leads to an alternative general framework in terms of motives associated to a Calabi–Yau variety in which it is possible to address the arithmetic nature of the attractor varieties in a universal way via Deligne's period conjecture.
Surface brillouin scattering from graphite

This report discusses the conflicting results of two previous Brillouin scattering determinations of the C{sub 44} elastic modulus of graphite.
The correct exponent for the Gotsman---Linial Conjecture

We prove new bounds on the average sensitivity of polynomial threshold functions. In particular, we show that for f, a degree-d polynomial threshold function in n variables that $$\mathbb{AS}(f) \leq \sqrt{n}(\log(n))^{O(d log(d))}2^{O(d^2 log(d))}.$$ AS ( f ) ≤ n ( log ( n ) ) O ( d l o g ( d ) ) 2 O ( d 2 l o g ( d ) ) . This bound amounts to a significant improvement over previous bounds, and in particular, for fixed d gives the same asymptotic exponent of n as the one predicted by the Gotsman---Linial Conjecture.
Hexaazaoctadecahydrocoronene. Structural and physical properties of [HOC]n (n=0, 1+, 2+, 3+, 4+)

Hexaazaoctadecahydrocoronene and its mono-, di-, tri-, and tetracations, (HOC){sup n} (n = 0, 1+, 2+, 3+, 4+), have been prepared and characterized by X-ray diffraction, EPR, magnetic susceptibility, and electronic and vibrational spectroscopies. HOC, (HOC){sup {sm bullet}+} (BF{sub 4}){sup {minus}}, (HOC){sup {sm bullet}+}(TCNE){sup {sm bullet}{minus}} (TCNE = tetracyanoethylene), (HOC){sup {sm bullet}+} (F{sub 3}CSO{sub 3}){sup {minus}}, (HOC){sup 2+}((PF{sub 6}){sup {minus}}){sub 2}, (HOC){sup 2+}((BF{sub 4}){sup {minus}}){sub 2}, (HOC){sup 2+}((C(CN){sub 3}){sup {minus}}){sub 2}, (HOC){sup 2+}(C(C(CN){sub 2}){sub 3}){sup 2{minus}}, (HOC){sup 2+}(Ni(S{sub 2}-C{sub 2}(CF{sub 3}){sub 2}){sub 2}{sup {sm bullet}{minus}}){sub 2}, (HOC){sup {sm bullet}3+}((PF{sub 6}){sup {minus}}){sub 3}, (HOC){sup {sm bullet}3+}((SbF{sub 6}){sup {minus}}){sub 3}, and (HOC){sup 4+}((SbF{sub 6}){sup {minus}}){sub 4}{center dot}MeCn have been studied by single-crystal X-ray diffraction. Solid-state magnetic susceptibility measurements show that the n = 0, 2+, and 4+ compounds are diamagnetic and that the n = 1+ and 3+ salts are S = {1/2} paramagnets that obey the Curie-Weiss expression between 2 and 320 K. The effective moments, {mu}{sub eff}, and Curie-Weiss constants, {theta}, are 1.77 and 1.75 {mu}{sub B} and {theta} = -3.3 and -0.9 K for the mono- and trications, respectively. The n = 1+ and 3+ radical cations are fluxional in solution. The EPR spectrum of (HOC){sup {sm bullet}+} in themore » fast-exchange limit (25{degree}C) shows that all protons and N's have the same hyperfine splitting (2.56 G, g = 2.00315). Solid-state magnetic susceptibility measurements for those (HOC){sup 2+} with singlet-triplet gaps less than 4.0 kcal/mol show increases in susceptibilities at higher temperatures, consistent with the presence of thermally populated triplet excited states.« less
SEAD: Secure efficient distance vector routing for mobile wireless ad hoc networks

Abstract An ad hoc network is a collection of wireless computers (nodes), communicating among themselves over possibly multihop paths, without the help of any infrastructure such as base stations or access points. Although many previous ad hoc network routing protocols have been based in part on distance vector approaches, they have generally assumed a trusted environment. In this paper, we design and evaluate the Secure Efficient Ad hoc Distance vector routing protocol (SEAD), a secure ad hoc network routing protocol based on the design of the Destination-Sequenced Distance-Vector routing protocol. In order to support use with nodes of limited CPU processing capability, and to guard against Denial-of-Service attacks in which an attacker attempts to cause other nodes to consume excess network bandwidth or processing time, we use efficient one-way hash functions and do not use asymmetric cryptographic operations in the protocol. SEAD performs well over the range of scenarios we tested, and is robust against multiple uncoordinated attackers creating incorrect routing state in any other node, even in spite of any active attackers or compromised nodes in the network.
Trialkylsilyloxyalkynes: Synthesis and aromatic annulation reactions

Abstract Substituted resorcinols are produced by the thermal addition of cyclobutenones to trialkylsilyloxyalkynes. The dehydrobromination of (Z)-2-bromovinyl silyl ethers has been employed in the first synthesis of trialkylsilyloxyethyne derivatives.
Reaction of 1O2 with alkoxyallylstannanes: Synthesis of 1,2-dioxolanes and allyl hydroperoxides

Abstract The reaction of 1 O 2 with chiral alkoxyallylstannanes provides a new route for the stereoselective synthesis of 1,2-dioxolanes and allyl hydroperoxides. Dioxolane formation, which proceeds through ring opening of the intermediate perepoxide upon migration of the stannyl group, is shown to be favored by the presence of an electron-donating group and by steric factors suppressing the more typical H-ene reaction.
The calcium sulfate-induced corrosion of iron-chromium alloys

Abstract The calcium sulfate-induced corrosion behavior of binary FeCr alloys has been studied at a temperature of 1223 K under an oxygen partial pressure of 10 −11.2 atm, generated using a CO/CO 2 gas mixture. These conditions are intended to simulate the oxygen activities in the low oxygen partial pressure locations in the fluidized-bed combustor. Under this low oxygen activity, the presence of calcium sulfate induces sulfidation/oxidation corrosion, and breakaway corrosion was observed for an Fe-20Cr alloy. The formation of internal Cr-rich sulfide/oxide particles in the underlying alloy below an inner Cr-rich oxide layer was generally observed. The reaction products between the oxide and the calcium salts formed at the external surface of scale on iron-chromium alloys, such as a eutectic CaO-Cr 2 O 3 oxide mixture, appear to be insignificant in controlling the overall degradation process. The corrosion mechanism appears to be a sulfidation/oxidation process consistent with the low oxygen partial pressure and the relatively high sulfur activity calculated from the CaOS equilibria.
Molecular Recognition of Neutral and Charged Guests using Metallomacrocyclic Hosts

Publisher Summary This chapter presents the molecular recognition of neutral and charged guests using metallomacrocyclic hosts. Macrocycles and metallomacrocycles have been used in the design of high-affinity, selective receptors for a variety of substrates. Small molecule guest ligands can be bound to the metallomacrocyclic host through sigma-donor and pi-acceptor interactions. Furthermore, the macrocycle itself can adopt cleft-like conformations suitable for 3D encapsulation of substrates. Additional receptor groups can be readily appended to the macrocyclic complexes in order to accomplish more complex multi-point guest recognition. The flexibility of the metallomacrocyclic receptors can be varied, so that either highly selective rigid hosts or more versatile flexible hosts can be obtained, as needed. The field of molecular recognition using metallomacrocycles started out with small molecule binding within well-defined cavities. Molecular recognition using functionalized metallomacrocyclic hosts has also been employed in the design of molecular machines. Finally, macrocyclic compounds have shown to be effective in recognizing large guests such as polyoxoanions, fullerenes, and carbon nanotubes.
S to P wave form factors in semi-leptonic B decays

We apply HQET to semi-leptonicB andBs meson decays into the observed charmedp wave states. In order to examine the sensitivity of the results to the choice of a specific model, we perform all calculations using several different meson models, and find that uncertainty introduced by the choice of a particular model is about 30%. Specifically, assumingτB=1.50ps andVcb=0.040, we obtain branching ratios of (0.27±0.08)% and (0.45±0.14)% for\(B \to D_1 l\bar \upsilon _1 \) and\(B \to D_2^* l\bar \upsilon _1 \) decays, respectively.
Control of Linear Systems by Output Proportional Plus Derivative Feedback

A design procedure for systems using proportional plus derivative output feedback for continuous and discrete time systems is presented. A performance index was developed that represents two major goals, regulation and sensitivity. Plant disturbances and measurement noise effects were quantified, as well as two sensitivity measures, eigenvalue sensitivity and response sensitivity. Several example problems were presented to illustrate the proposed design method
Identification of SM-OFDM and AL-OFDM Signals Based on Their Second-Order Cyclostationarity

Automatic signal identification (ASI) has important applications to both commercial and military communications, such as software-defined radio, cognitive radio, spectrum surveillance and monitoring, and electronic warfare. While ASI has been intensively studied for single-input single-output systems, only a few investigations have been recently presented for multiple-input multiple-output (MIMO) systems. This paper introduces a novel algorithm for the identification of spatial multiplexing (SM) and Alamouti (AL)-coded orthogonal frequency-division multiplexing (OFDM) signals, which relies on second-order signal cyclostationarity. Analytical expressions for the second-order cyclic statistics of the SM-OFDM and AL-OFDM signals are derived and further exploited for algorithm development. The proposed algorithm provides a good identification performance with low sensitivity to impairments in the received signal, such as phase noise, timing offset, and channel conditions.
An evaluation of caching policies for memento timemaps

As defined by the Memento Framework, TimeMaps are machine-readable lists of time-specific copies -- called "mementos" -- of an archived original resource. In theory, as an archive acquires additional mementos over time, a TimeMap should be monotonically increasing. However, there are reasons why the number of mementos in a TimeMap would decrease, for example: archival redaction of some or all of the mementos, archival restructuring, and transient errors of one or more archives. We study TimeMaps for 4,000 original resources over a three month period, note their change patterns, and develop a caching algorithm for TimeMaps suitable for a reverse proxy in front of a Memento aggregator. We show that TimeMap cardinality is constant or monotonically increasing for 80.2% of all TimeMap downloads in the observation period. The goal of the caching algorithm is to exploit the ideally monotonically increasing nature of TimeMaps and not cache responses with fewer mementos than the already cached TimeMap. This new caching algorithm uses conditional cache replacement and a Time To Live (TTL) value to ensure the user has access to the most complete TimeMap available. Based on our empirical data, a TTL of 15 days will minimize the number of mementos missed by users, and minimize the load on archives contributing to TimeMaps.
Heat transfer in inertial confinement fusion reactor systems

The transfer of energy produced by the interaction of the intense pulses of short-ranged fusion microexplosion products with materials is one of the most difficult problems in inertially-confined fusion (ICF) reactor design. The short time and deposition distance for the energy results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. High local power densities may cause change of state or spall in the reactor materials. This will limit the structure lifetimes for ICF reactors of economic physical sizes, increasing operating costs including structure replacement and radioactive waste management. Four basic first wall protection methods have evolved: a dry-wall, a wet-wall, a magnetically shielded wall, and a fluid wall. These approaches are distinguished by the way the reactor wall interfaces with fusion debris as well as the way the ambient cavity conditions modify the fusion energy forms and spectra at the first wall. Each of these approaches requires different heat transfer considerations.
Slideshow: functional presentations

Among systems for creating slide presentations, the dominant ones offer essentially no abstraction capability. Slideshow represents our effort over the last several years to build an abstraction-friendly slide system with PLT Scheme. We show how functional programming is well suited to the task of slide creation, we report on the programming contructs that we have developed for slides, and we describe our solutions to practical problems in rendering slides. We also describe experimental extensions to DrScheme that support a mixture of programmatic and WYSIWYG slide creation.
Robustness Analysis and Robust Design of Uncertain Systems

This paper proposes a methodology for the analysis and design of systems subject to parametric uncertainty in which design requirements are specified via hard inequality constraints. Hard constraints are those that must be satisfied for all parameter realizations within a given uncertainty model. Uncertainty models given by norm-bounded perturbations from a nominal parameter value (i.e., hyperspheres) and by sets of independently bounded uncertain variables (i.e., hyperrectangles) are the focus of this paper. These models, which are also quite practical, allow for a rigorous mathematical treatment within the proposed framework. Hard-constraint feasibility is determined by sizing the largest uncertainty set for which the design requirements are satisfied. Assessments of robustness are attained by comparing this set with the actual uncertainty model. These assessments do not suffer from the numerical deficiencies of sampling-based methods. Strategies that enable the comparison of the robustness characteristics of competing design alternatives, the approximation of the robust design space, and the systematic search for designs with improved robustness are also proposed. Because the problem formulation is generic and the tools derived only require standard optimization algorithms for their implementation, this methodology is applicable to a broad range of engineering problems.