cssi/SciSciGPT-SciSciNet huggingface dataset:
Gear crack propagation investigations

Abstract : Analytical and experimental studies were performed to investigate the effect of gear rim thickness on crack propagation life. The FRANC (FRacture ANalysis Code) computer program was used to simulate crack propagation. The FRANC program used principles of linear elastic fracture mechanics, finite element modeling, and a unique re-meshing scheme to determine crack tip stress distributions, estimate stress intensity factors, and model crack propagation. Various fatigue crack growth models were used to estimate crack propagation life based on the calculated stress intensity factors. Experimental tests were performed in a gear fatigue rig to validate predicted crack propagation results. Test gears were installed with special crack propagation gages in the tooth fillet region to measure bending fatigue crack growth. Good correlation between predicted and measured crack growth was achieved when the fatigue crack closure concept was introduced into the analysis. As the gear rim thickness decreased, the compressive cyclic stress in the gear tooth fillet region increased. This retarded crack growth and increased the number of crack propagation cycles to failure.
Gamma-Ray Burst Spectral Features: Interpretation as X-Ray Emission from a Photoionized Plasma

Numerous reports have been made of features, in either emission or absorption, in the 10-1000 keV spectra of some gamma-ray bursts. Originally interpreted in the context of Galactic neutron star models as cyclotron line emission and e+-e- annihilation features, the recent demonstration that the majority of gamma-ray bursts (GRBs) lie at cosmological distances makes these explanations unlikely. In this Letter, we adopt a relativistic fireball model for cosmological GRBs in which dense, metal-rich blobs or filaments of plasma are entrained in the relativistic outflow. In the context of this model, we investigate the conditions under which broadband features, similar to those detected, can be observed. We find a limited region of parameter space capable of reproducing the observed GRB spectra. Finally, we discuss possible constraints additional high-energy spectral observations could place on fireball model parameters.
Calling recessions in real time

Abstract This paper surveys efforts to automate the dating of business cycle turning points. Doing this on a real time, out-of-sample basis is a bigger challenge than many academics might assume, due to factors such as data revisions and changes in economic relationships over time. The paper stresses the value of both simulated real-time analysis — looking at what the inference of a proposed model would have been using data as they were actually released at the time — and actual real-time analysis, in which a researcher stakes his or her reputation on publicly using the model to generate out-of-sample, real-time predictions. The immediate publication capabilities of the internet make the latter a realistic option for researchers today, and many are taking advantage of it. The paper reviews a number of approaches to dating business cycle turning points and emphasizes the fundamental trade-off between parsimony — trying to keep the model as simple and robust as possible — and making full use of the available information. Different approaches have different advantages, and the paper concludes that there may be gains from combining the best features of several different approaches.
The Next Geminga: Search for Radio and X-ray Pulsations from the Neutron Star Identified with 3EG J1835+5918

We report unsuccessful searches for pulsations from the neutron star RX J1836.2+5925, identified with the EGRET source 3EG J1835+5918. A 24 hr observation with the NRAO Green Bank Telescope at 820 MHz placed an upper limit on flux density of 17 μJy for P 10 ms, and gradually increasing limits for 1 P 10 ms. The equivalent luminosity is lower than that of any known pulsar, with the possible exception of the radio-quiet γ-ray pulsar Geminga. A set of observations with the Chandra X-ray Observatory HRC totaling 118 ks revealed no pulsar with 1 ms ≤ P ≤ 10 s. The upper limit on its pulsed fraction is 35% assuming a sinusoidal pulse shape. The position of RX J1836.2+5925 in Chandra observations separated by 3 years is unchanged within errors, leading to an upper limit on its proper motion of <0.14'' yr-1, or vt < 530 km s-1 at d = 800 pc, a maximum distance estimated from its thermal X-ray spectrum. With these null results, the properties of 3EG J1835+5918 and its X-ray counterpart RX J1836.2+5925 are consistent with a more distant or older version of Geminga, or perhaps a recycled pulsar. Having nearly exhausted the capabilities of current instrumentation at all wavelengths, it will likely fall to the Gamma-ray Large Area Space Telescope to discover pulsations from 3EG J1835+5918.
Maximal neutrino mixing from an attractive infrared fixed point

Abstract In the Standard Model (and MSSM), renormalization effects on neutrino mixing are generally very small and the attractive fixed points are at vanishing neutrino mixing. However for multi-Higgs extensions of the Standard Model, renormalization effects on neutrino mixing can be large and nontrivial fixed points are possible. Here we examine a simple two-Higgs model. For two flavors, maximal mixing is an attractive infrared fixed point. For three flavors, the neutrino mass matrix evolves towards large off-diagonal elements at low energies. The experimentally suggested bimaximal neutrino mixing pattern is one possible attractive infrared fixed point.
The Rotational Spectrum of HCl

The rotational spectrum of the radical ion HCl{sup +} has been detected at high resolution in the laboratory, confirming the identification reported in the accompanying Letter by De Luca et al., in diffuse clouds toward W31C and W49N. Three rotational transitions, one in the ground-state {sup 2}{Pi}{sub 3/2} ladder and two in the {sup 2}{Pi}{sub 1/2} ladder (643 cm{sup -1} above ground), were observed in a microwave discharge of He and HCl. Well-resolved chlorine hyperfine structure and {Lambda}-doubling, and the detection of lines of H{sup 37}Cl{sup +} at precisely the expected isotopic shift, provide conclusive evidence for the laboratory identification. Detection of rotational transitions in the {sup 2}{Pi}{sub 1/2} ladder of HCl{sup +} for the first time allows an experimental determination of the individual hyperfine coupling constants of chlorine and yields a precise value of eQq{sub 2}. The spectroscopic constants obtained by fitting a Hamiltonian simultaneously to our data and more than 8000 optical transitions are so precise that they allow us to calculate the frequencies of the {sup 2}{Pi}{sub 3/2} J = 5/2 - 3/2 transition observed in space to within 0.2 km s{sup -1}, and indeed, those of the strongest rotational transitions below 7.5 THz, to better thanmore » 1 km s{sup -1}.« less
A NEW STRUCTURAL FORM OF TIN IN A CUBIC CLUSTER

Abstract We have reported new forms of tin comprised of oligomeric oxotin carboxylates that are based on the compositions [R'Sn(O)O2CR]6 1-5 and [(R'Sn(O)O2CR)2-R'Sn(O2CR)3]2.2-5 These have “drum” and “ladder” structures, respectively. We also reported the oxygen-capped cluster, [(n-BuSn(OH)O2PPh2)3O]-[Ph2PO2],6 which has tin in a partial cubic array surrounded by chelating phosphinate groups. In all of these forms, tin generally is octahedrally coordinated. One useful synthetic route for their formation employs the interaction of an alkyl or aryl stannoic acid with either a carboxylic acid or a phosphorus-containing acid.
Small-molecule fluorescent sensors for investigating zinc metalloneurochemistry.

The metalloneurochemistry of Zn(II) is of substantial current interest. Zinc is the second most abundant d-block metal ion in the human brain, and its distribution varies with relatively high concentrations found in the hippocampus. Brain zinc is generally divided into two types, protein-bound and loosely bound, the latter also being termed histochemically observable, chelatable, labile, or mobile zinc. The neurophysiological and neuropathological significance of mobile Zn(II) remains enigmatic. Studies of Zn(II) distribution, translocation, and function in vivo require tools for its detection. Because Zn(II) has a closed-shell d10 configuration and no convenient spectroscopic signature, fluorescence is a well-suited method for monitoring Zn(II) in biological contexts. This Account summarizes work by our laboratory addressing the design, preparation, characterization, and use of small-molecule fluorescent sensors for imaging Zn(II) in living cells and samples of brain tissue. These sensors provide “turn-o...
Value Creation, Value Capture, and Supply Chain Structure: Understanding Resource–Based Advantage in a Project–Based Industry

Understanding supply chain resilience and robustness is increasingly important for supply chain managers. This is due to the growing complexity of contemporary supply chains and the subsequent increased probability of experiencing a disruption. Few studies within the risk management literature have empirically disentangled the concepts of resilience and robustness or explored their antecedents. This study utilizes a contingent resource-based view perspective to understand the relationship between specific resources (information sharing and connectivity), capabilities (visibility), and performance in terms of supply chain resilience and robustness. In addition, it utilizes supply base complexity as a moderating factor. Survey data collected from 264 UK manufacturing plants suggest that supply chain connectivity and information sharing resources lead to a supply chain visibility capability which enhances resilience and robustness. Of the four dimensions of complexity, only scale is found to have a strong moderating effect on this relationship, while geographic dispersion, differentiation, and delivery complexity do not have contingent effects. This study highlights theoretical and managerial implications for approaches to resilience and robustness.
Quantitative Determination of the Mechanical Properties of Shales

Shales make up more than 75% of drilled formations and cause at least 90% of wellbore-stability problems. Physical measurements of shale properties are required to develop realistic constitutive relationships and to understand and define shale strength and behavior under downhole conditions. Quantitative shale-strength data are needed to improve wellbore-stability model predictions. This paper describes a research test program to determine the mechanical properties of different classes of shales and to build a database on their characteristics and mechanical behavior. Shale samples from undisturbed block samples were prepared under controlled conditions. Mechanical test techniques were developed to measure effective-stress/strain properties accurately for shales. The tests require a heavy-duty, triaxial test load frame and other specially designed equipment to obtain precise pore pressure measurements. During the tests, pore pressure, stresses, and strains were monitored accurately by an automatic data-acquisition system. The test techniques described can be used to test shales with different characteristics: soft, hard, brittle, plastic, etc. On the basis on results of several shale tests, high-quality, effective-stress/strain data and failure criteria (shale strength relationships) can be obtained routinely.
The synthesis of 1-alkylthiopyrroles

Abstract Reaction of various S-substituted thiophthalimides or thiosuccinimides and pyrrole, under phase transfer conditions, provides an efficient way to prepare 1-alkylthiopyrroles in high yield.
The Application of Automatic Testing to Complex Nuclear Physics Experiments

The complexity of the data-acquisition systems required for advanced nuclear physics experiments is increasing. The difficulties involved both in setting up these systems and in detecting failures or drifts in the associated electronic equipment increase rapidly with the complexity of the system. To alleviate these difficulties, some automatic test routines for checking a complete data-acquisition system from phototube to scaler or analyzer have been developed. One technique involves the use of the nanosecond light pulsers described by Kerns. These are mounted so as to illuminate the scintillators. Relay matrices for routing the electrical triggers to the pulsers have been developed. The routing is programmed to sequentially activate various combinations of light pulsers, thereby simulating the nuclear events under investigation, as well as accidental events. Control systems are provided to perform the programming, with either automatic or manually controlled sequencing. Methods of checking or recording the results of the test routine are discussed. Two applications of this technique to actual experiments are described.
Rent Control, Rental Housing Supply, and the Distribution of Tenant Benefits

Abstract This paper estimates the net benefits of rent control to tenants in New York City. Although other studies have measured these benefits, all assume that the price per unit of rental housing service in the uncontrolled sector is unaffected by the existence of rent controls. That assumption is relaxed in this study. The results suggest that, controlling for higher prices in the uncontrolled sector, the average benefit to tenants in regulated units is negative. This implies that, on average, tenants in rent regulated units would be better off if these controls had never been established.
Tail behavior of solutions of linear recursions on trees

Abstract Consider the linear nonhomogeneous fixed-point equation R = D ∑ i = 1 N C i R i + Q , where ( Q , N , C 1 , C 2 , … ) is a random vector with N ∈ { 0 , 1 , 2 , 3 , … } ∪ { ∞ } , C i ≥ 0 for all i ∈ N , P ( | Q | > 0 ) > 0 , and { R i } i ∈ N is a sequence of i.i.d. random variables independent of ( Q , N , C 1 , C 2 , … ) having the same distribution as R . It is known that R will have a heavy-tailed distribution under several different sets of assumptions on the vector ( Q , N , C 1 , C 2 , … ) . This paper investigates the settings where either Z N = ∑ i = 1 N C i or Q are regularly varying with index − α − 1 and E [ ∑ i = 1 N C i α ] 1 . This work complements previous results showing that P ( R > t ) ∼ H t − α provided there exists a solution α > 0 to the equation E [ ∑ i = 1 N | C i | α ] = 1 , and both Q and Z N have lighter tails.
Design of Gate Delay and Gate Interval Time for Four-Quadrant Gate System at Railroad-Highway Grade Crossings

A design methodology for gate delay and gate interval time for at-grade crossings using four-quadrant gates is developed. The design approach is based on the concept of dilemma zones related to signal change intervals at signalized intersections. The design approach is validated based on data from six sites in Illinois on a proposed high-speed rail corridor. Gate delay and gate interval times are determined that provide an optimal safe decision point to allow a driver to stop before the crossing or to proceed through the crossing without becoming trapped by the exit gates.
13C NMR Quantitative Spectrometric Data-Activity Relationship (QSDAR) Models of Steroids Binding the Aromatase Enzyme

Five quantitative spectroscopic data-activity relationships (QSDAR) models for 50 steroidal inhibitors binding to aromatase enzyme have been developed based on simulated (13)C nuclear magnetic resonance (NMR) data. Three of the models were based on comparative spectral analysis (CoSA), and the two other models were based on comparative structurally assigned spectral analysis (CoSASA). A CoSA QSDAR model based on five principal components had an explained variance (r(2)) of 0.78 and a leave-one-out (LOO) cross-validated variance (q(2)) of 0.71. A CoSASA model that used the assigned (13)C NMR chemical shifts from a steroidal backbone at five selected positions gave an r(2) of 0.75 and a q(2) of 0.66. The (13)C NMR chemical shifts from atoms in the steroid template position 9, 6, 3, and 7 each had correlations greater than 0.6 with the relative binding activity to the aromatase enzyme. All five QSDAR models had explained and cross-validated variances that were better than the explained and cross-validated variances from a five structural parameter quantitative structure-activity relationship (QSAR) model of the same compounds. QSAR modeling suffers from errors introduced by the assumptions and approximations used in partial charges, dielectric constants, and the molecular alignment process of one structural conformation. One postulated reason that the variances of QSDAR models are better than the QSAR models is that (13)C NMR spectral data, based on quantum mechanical principles, are more reflective of binding than the QSAR model's calculated electrostatic potentials and molecular alignment process. The QSDAR models provide a rapid, simple way to model the steroid inhibitor activity in relation to the aromatase enzyme.
The BG-rank of a partition and its applications

Let @p denote a partition into parts @l"1>=@l"2>=@l"3>=.... In a 2006 paper we defined BG-rank(@p) asBG-rank(@p)=@?j>=1(-1)^j^+^11-(-1)^@l^"^j2. This statistic was employed to generalize and refine the famous Ramanujan modulo 5 partition congruence. Let p"j(n) denote the number of partitions of n with BG-rank=j. Here, we provide a combinatorial proof thatp"j(5n+4)=0(mod5),j@?Z, by showing that the residue of the 5-core crank mod 5 divides the partitions enumerated by p"j(5n+4) into five equal classes. This proof uses the orbit construction from our previous paper and a new identity for the BG-rank. Let a"t","j(n) denote the number of t-cores of n with BG-rank=j. We find eta-quotient representations for@?n>=0a"t","@?"t"+"1"4"@?(n)q^nand@?n>=0a"t","-"@?"t"-"1"4"@?(n)q^n, when t is an odd, positive integer. Finally, we derive explicit formulas for the coefficients a"5","j(n), j=0,+/-1.
Genomics in space life sciences.

Since the early days of manned spaceflight, hazardous effects of the space environment on living organisms have been disputed. With the continuous manning of the International Space Station, the planned Chinese space station, and renewed interest in returning to the Moon and sending manned flights to Mars, identifying and addressing the potential outcomes of long-term space exposures is critically important. Space-flown and ground-based research Much progress has been made towards the understanding of the effect of space environmental factors, especially microgravity and radiation, on living organisms. During the space exploration of the 1970s, physiological changes in several organ systems due to weightlessness were identified. Some of the adverse effects are a decline in cellular immune responses (1{ 3), cardiovascular deconditioning (4), bone deterioration (5), and muscular atrophy (6). Furthermore, simulated microgravity studies have shown increased virulence in microorganisms (7). Over the past 30 years, a number of in vitro studies have been carried out in space. However, the cost and logistics of conducting space-flown studies have not allowed indepth interpretation of the data because of small sample sizes (8). Therefore, ground-based research has become common in space life sciences. Those simulated microgravity studies include head-down bed rest for humans (9), tail suspension for rodents (10), and cell and microorganism cultures with high aspect ratio vessel (HARV) bioreactors (11;12) and random positioning machine (RPM) (13).
Cosmic Mach Number as a Function of Overdensity and Galaxy Age

We carry out an extensive study of the cosmic Mach number () on scales of R = 5, 10, and 20 h-1 Mpc using a ?-dominated flat cold dark matter hydrodynamical simulation. We particularly put emphasis on the environmental dependence of on overdensity, galaxy mass, and galaxy age. We start by discussing the difference in the resulting according to different definitions of and different methods of calculation. The simulated Mach numbers are slightly lower than the linear theory predictions even when a nonlinear power spectrum was used in the calculation, reflecting the nonlinear evolution in the simulation. We find that the observed is higher than the simulated mean by more than 2 standard deviations, which suggests either that the Local Group is in a relatively low density region or that the true value of ?m is ~0.2, significantly lower than the simulated value of 0.37. We show from our simulation that the Mach number is a weakly decreasing function of overdensity. We also investigate the correlations between galaxy age, overdensity, and for two different samples of galaxies?DWARFs and GIANTs. Older systems cluster in higher density regions with lower , while younger ones tend to reside in lower density regions with larger , as expected from the hierarchical structure formation scenario. However, for DWARFs, the correlation is weakened by the fact that some of the oldest DWARFs are left over in low-density regions during the structure formation history. For giant systems, one expects blue-selected samples to have higher than red-selected ones. We briefly comment on the effect of the warm dark matter on the expected Mach number.
An efficient synthesis of furyl sulfonamides from the reaction of furan with in situ generated N-tosyl imines

Abstract Treatment of an aldehyde and furan with N-sulfinyl-p-toluenesulfonamide/zinc chloride leads to the formation of furyl sulfonamides via an in situ generated N-tosyl imine intermediate. In one case, a novel 4-tosylamino-5,6-dihydro-4H-3-oxa-benz[e]azulene was obtained by intramolecular aromatic substitution of the activated imine at the 3-position of the furan ring.
AFS and the Web: competitors or collaborators?

Over the last few years, the World-Wide Web [2] has risen to dominance as a mechanism for wide-area information access. Each day brings new reports of the growth of the Web, and this trend shows no signs of abating any time soon. To many people, the Web and the Internet are synonymous. Unfortunately, success has exposed many limitations of the Web such as its tendency to overload the network and servers, its limited ability to control access to sensitive data, its lack of mechanisms for data consistency, and its susceptibility to network and server failures. It is now widely recognized that these problems must be solved for the continued growth of the Web.With much less fanfare, another world-wide information system, AFS, has also been operational on the Internet. AFS was originally designed to support the file sharing needs of a campus-sized community of five to seven thousand workstations [11, 15]. In current parlance, AFS was conceived as an information sharing mechanism for the Intranet of an organization. Since then, AFS has been evolved to function effectively over the Internet [17, 21]. Many organizations have been part of a single distributed Unix file name space supported by AFS. As of 1994, this system spanned well over 100 organizations world-wide, with each organization typically containing many tens or hundreds of clients. Measurements reported in a recent paper [20] confirm that AFS does indeed function effectively at this scale.The goal of this paper is to critically compare these two mechanisms for world-wide information access. We begin by asking the following questions:• What are the relative strengths and weaknesses of the two mechanisms?• Which of these differences are superficial, and which are deep?• Why is the Web so much more visible and popular?In performing this comparison, it is important to keep in mind that the two mechanisms are not addressing precisely the same problem. While AFS has the relatively narrow and well-defined goal of provided distributed Unix file access, the goal of the Web is broader and less explicit. Further, AFS is now stable and mature while many aspects of the Web are still evolving. In spite of these caveats, we believe that a comparison of the two mechanisms will provide useful insights.Our comparison shows that the Web and AFS are not really competing technologies. Rather, they represent complementary technologies that may be used together for mutual advantage. We present real-life examples to confirm that this potential can indeed be realized in practice.
Dose-response curve of EBT, EBT2, and EBT3 radiochromic films to synchrotron-produced monochromatic x-ray beams

Purpose: This work investigates the dose-response curves of GAFCHROMIC ® EBT, EBT2, and EBT3
A convenient, highly stereoselective synthesis of anti-α,β-epoxy alcohols by the Luche reduction of α,β-epoxy ketones

Abstract Reduction of α,β-epoxy ketones under the Luche conditions with NaBH 4 /CeCl 3 in MeOH provides anti- (or erythro-) α,β-epoxy alcohols in high yields and with extremely high stereoselectivity.
Managing Resistance Evolution in Two Pests to Two Toxins with Refugia

We use a regulatory model with resistance evolution in two pests to insecticidal Bt cotton and pyrethroids (a conventional insecticide) to examine non-Bt cotton (refuge) planting requirements designed to manage Bt-resistance evolution in the midsouth. Our analysis suggests that reduced refuge requirements would enhance producer profitability, sprayed refugia are more cost effective than unsprayed refugia, and producers would receive slightly higher returns under dynamic relative to static refuge policies. Pyrethroid susceptibility in one of the pests was a renewable resource, and toxin-mixture effects associated with pyrethroid use in Bt cotton were important considerations for midsouth refuge policies.
Classification approach for reliability-based topology optimization using probabilistic neural networks

This research explores the usage of classification approaches in order to facilitate the accurate estimation of probabilistic constraints in optimization problems under uncertainty. The efficiency of the proposed framework is achieved with the combination of a conventional topology optimization method and a classification approach- namely, probabilistic neural networks (PNN). Specifically, the implemented framework using PNN is useful in the case of highly nonlinear or disjoint failure domain problems. The effectiveness of the proposed framework is demonstrated with three examples. The first example deals with the estimation of the limit state function in the case of disjoint failure domains. The second example shows the efficacy of the proposed method in the design of stiffest structure through the topology optimization process with the consideration of random field inputs and disjoint failure phenomenon, such as buckling. The third example demonstrates the applicability of the proposed method in a practical engineering problem.
Domain Wall Switching: Optimizing the Energy Landscape

It has recently been suggested that exchange spring media offer a way to increase media density without causing thermal instability (superparamagnetism), by using a hard and a soft layer coupled by exchange. Victora has suggested a figure of merit xi=2Eb/mu0msHsw, the ratio of the energy barrier to that of a Stoner-Wohlfarth system with the same switching field, which is 1 for a Stoner-Wohlfarth (coherently switching) particle and 2 for an optimal two-layer composite medium. A number of theoretical approaches have been used for this problem (e.g., various numbers of coupled Stoner-Wohlfarth layers and continuum micromagnetics). In this paper we show that many of these approaches can be regarded as special cases or approximations to a variational formulation of the problem, in which the energy is minimized for fixed magnetization. The results can be easily visualized in terms of a plot of the energy E as a function of magnetic moment mz, in which both the switching field [the maximum slope of E(mz)] and the stability (determined by the energy barrier DeltaE) are geometrically visible. In this formulation we can prove a rigorous limit on the figure of merit xi, which can be no higher than 4. We also show that a quadratic anistropy suggested by Suess comes very close to this limit.
Specific synthesis and stereochemical assignment of the diastereomeric 3,5-O-benzylidene-1,2-O-isopropylidene-α-d-glucofuranose isomers

Pyridinium tosylate-catalyzed acetal exchange between benzaldehyde dimethyl acetal and 6-O-(tert-butyldiphenylsilyl)-1,2-O-isopropylidene-alpha-D-glucofu ranose was investigated as an alternative to the original procedure of Brigl and Gruner (condensation of a D-glucose triol with benzaldehyde under zinc halide catalysis) for synthesis of 3,5-O-benzylidene-1,2-O-isopropylidene-alpha-D-glucofuranose. The two routes afford opposite benzylidene diastereoisomers: the traditional procedure leads to the thermodynamically favored isomer (phenyl and C-6 trans), whereas the new sequence gives the cis compound. The orientations and conformations of these isomers were determined after conversion into the corresponding 6-iodides 5 and 7. X-Ray crystallography revealed that the 1,3-dioxane ring of the trans isomer 7 exists in the expected chair, "O-inside" conformation. In contrast, a combination of n.m.r. spectroscopy and molecular-mechanics calculations demonstrated that the same ring of cis diastereomer 5 does not adopt the alternative chair, "H-inside" conformation; instead, it exists in a specific twist form.
Microscale receiver operating characteristic analysis of micrometastasis recognition using activatable fluorescent probes indicates leukocyte imaging as a critical factor to enhance accuracy

Molecular-targeted probes are emerging with applications for optical biopsy of cancer. An underexplored potential clinical use of these probes is to monitor residual cancer micrometastases that escape cytoreductive surgery and chemotherapy. Here, we show that leukocytes, or white blood cells, residing in nontumor tissues—as well as those infiltrating micrometastatic lesions—uptake cancer cell-targeted, activatable immunoconjugates nonspecifically, which limits the accuracy and resolution of micrometastasis recognition using these probes. Receiver operating characteristic analysis of freshly excised tissues from a mouse model of peritoneal carcinomatosis suggests that dual-color imaging, adding an immunostain for leukocytes, offers promise for enabling accurate recognition of single cancer cells. Our results indicate that leukocyte identification improves micrometastasis recognition sensitivity and specificity from 92 to 93%—for multicellular metastases >20 to 30 μm in size—to 98 to 99.9% for resolving metastases as small as a single cell.
The user experience: designs and adaptations

Specifications for accessibility of Web pages do not necessarily guarantee a usable or satisfying Web experience for persons with disabilities. The needs of many of these individuals fall outside guidelines for accessible content. Many of these users, for example, wish that they simply could "enlarge" what is on a Web page. They also express the wish that pages would be "less confusing". To meet these needs, Web browsers and various software applications provide for a variety of ways in which page presentations can be altered. The effects of these alterations often have unexpected consequences. Some designs accommodate these alterations better than others. This paper discusses one such application that allows users to control features of Web page presentation and explores design features that facilitate such control.
Using an Ellipsoid Model to Track and Predict the Evolution and Propagation of Coronal Mass Ejections

We present a method for tracking and predicting the propagation and evolution of coronal mass ejections (CMEs) using the imagers on the STEREO and SOHO satellites. By empirically modeling the material between the inner core and leading edge of a CME as an expanding, outward propagating ellipsoid, we track its evolution in three-dimensional space. Though more complex empirical CME models have been developed, we examine the accuracy of this relatively simple geometric model, which incorporates relatively few physical assumptions, including i) a constant propagation angle and ii) an azimuthally symmetric structure. Testing our ellipsoid model developed herein on three separate CMEs, we find that it is an effective tool for predicting the arrival of density enhancements and the duration of each event near 1 AU. For each CME studied, the trends in the trajectory, as well as the radial and transverse expansion are studied from 0 to ∼0.3 AU to create predictions at 1 AU with an average accuracy of 2.9 hours.
Broker-Dealer Risk Appetite and Commodity Returns

This paper shows that the risk-bearing capacity of security brokers and dealers is a strong determinant of risk premia and return volatility in commodity markets. I measure risk-bearing capacity as the fraction of brokerdealer …nancial assets relative to the total …nancial assets of broker-dealers and households. This variable has particularly strong forecasting power for energy returns, both in-sample and out-of-sample: it forecasts approximately 30% of the variation in quarterly crude oil returns. I rationalize the …ndings in a simple asset pricing model where the economic role of broker-dealers is to provide insurance against commodity price ‡uctuations. I estimate cross-sectional prices of risk using an arbitrage-free asset pricing approach and show that broker-dealer risk-bearing capacity forecasts commodity returns because of its association with the price of risk.
Optical switching using fiber ring reflectors

We present the results of studies of fiber ring reflectors that are pulse excited in the negative dispersion regime. An intensity-dependent fiber switch is proposed for improved thresholding and pulse output characteristics over those previously reported. Schemes for fiber switches relying on solitary-wave collision-induced phase shifts are also discussed. A pulse regenerator and logic gates are proposed, each capable of correcting timing drifts.
On fusion categories

Using a variety of methods developed in the literature (in particular, the theory of weak Hopf algebras), we prove a number of general results about fusion categories in characteristic zero. We show that the global dimension of a fusion category is always positive, and that the S-matrix of any (not necessarily hermitian) modular category is unitary. We also show that the category of module functors between two module categories over a fusion category is semisimple, and that fusion categories and tensor functors between them are undeformable (generalized Ocneanu rigidity). In particular the number of such categories (functors) realizing a given fusion datum is finite. Finally, we develop the theory of Frobenius-Perron dimensions in an arbitrary fusion category. At the end of the paper we generalize some of these results to positive characteristic.
Differential changes in the value-relevance of earnings and book values over time: financial versus other industries

We investigate the change in the value-relevance of earnings and book value information in the financial industry compared to other industries from 1970 to 2005. Prior literature provides mixed evidence as to whether value-relevance reduces over time. Our sample consists of 34,252 firm-year observations in the financial industry and 160,206 observations in other industries. This paper utilises both univariate and multivariate analysis [Ohlson’s (1995) model] to test the hypotheses. We find increasing value-relevance for earnings and book value for both financial and other industries. However, the increasing trend is less evident for financial firms. More importantly, we document that the slower growth trend for the financial industry improves compared to other industries after firms adopt SFAS 133 (as amended by SFAS 137 and 138) in 2001, since financial institutions typically hold more SFAS-133-related derivative instruments and hedging portfolios than other industries. Our results are thus consistent with the view that SFAS 133 may help financial institutions improve the value-relevance of accounting information. Thus, our results have implication for policy makers when they evaluate the benefit of SFAS 133.
3-Aminoxypropionate-based linker system for cyclization activation in prodrug design.

Abstract A novel linker system based on 3-aminoxypropionate was designed and evaluated for drug release using proteolysis as an activation trigger followed by intramolecular cyclization. The hydroxylamine moiety present in the linker system enabled faster release of the parent drug from the linker–drug conjugate at lower pH as compared to an aliphatic amine moiety. Introduction of two methyl groups strategically at the α position to the carboxylate in the linker further improved the rate of cyclization by nearly 2-fold. The 3-aminoxypropionate linker was successfully applied to a model prodrug for protease activation using α-chymotrypsin as the activating enzyme; the activation of the model prodrug bearing the 3-aminoxypropionate linker was 136 times faster than the corresponding model prodrug bearing an amine linker.
Extended Bayesian Information Criteria for Gaussian Graphical Models

Gaussian graphical models with sparsity in the inverse covariance matrix are of significant interest in many modern applications. For the problem of recovering the graphical structure, information criteria provide useful optimization objectives for algorithms searching through sets of graphs or for selection of tuning parameters of other methods such as the graphical lasso, which is a likelihood penalization technique. In this paper we establish the consistency of an extended Bayesian information criterion for Gaussian graphical models in a scenario where both the number of variables p and the sample size n grow. Compared to earlier work on the regression case, our treatment allows for growth in the number of non-zero parameters in the true model, which is necessary in order to cover connected graphs. We demonstrate the performance of this criterion on simulated data when used in conjunction with the graphical lasso, and verify that the criterion indeed performs better than either cross-validation or the ordinary Bayesian information criterion when p and the number of non-zero parameters q both scale with n.
Contrasts in sea ice deformation and production in the Arctic seasonal and perennial ice zones

Four years (1997-2000) of RADARSAT Geophysical Processor System (RGPS) data are used to contrast the sea ice deformation and production regionally, and in the seasonal (SIZ) and perennial (PIZ) ice zones. Ice production is of seasonal ice in openings during the winter. 3-day estimates of these quantities are provided within Lagrangian elements initially 10 km on a side. A distinct seasonal cycle is seen in both zones with these estimates highest in the late fall and with seasonal minimums in the mid-winter. Regional divergence over the winter could be up to 30%. Spatially, the highest deformation is in the SIZ north of coastal Alaska. Both ice deformation and production are higher in the SIZ: deformation-related ice production in the SIZ (approx.0.5 m) is 1.5-2.3 times that of the PIZ (approx.0.3 m) - this is connected to ice strength and thickness. Atmospheric forcing and boundary layer structure contribute to only the seasonal and interannual variability. Seasonal ice growth in ice fractures accounts for approx.25-40% of the total ice production of the Arctic Ocean. By itself, this deformation-ice production relationship could be considered a negative feedback when thickness is perturbed. However, the overall effect on ice production in the face of increasing seasonal and thinner/weaker ice coverage could be modified by: local destabilization of the water column promoting overturning of warmer water due to increased brine rejection; and, the upwelling of the pynocline associated with increased occurrence of large shear motion in sea ice.
Quantum Mechanics as a Generalized Stochastic Theory in Phase Space

In this paper we formulate a new stochastic description of quantum mechanics in phase space. The theory of phase-space representations of quantum mechanics, initiated by Wigner, Groenewold, and Moyal and systematized recently by Agarwal and Wolf is essentially a single-time theory, in that it deals only with the quantum-mechanical joint distribution functions for position and momentum at a single instant of time. We develop a natural multitime extension of such a single-time theory. We consider a class of multitime phase-space distribution functions such that an arbitrary quantum multitime correlation function can be expressed as a phase-space average of the form encountered in classical stochastic theories. We study the nonclassical features of these multitime distribution functions and show that they may be considered as characterizing a generalized stochastic process in phase space. We demonstrate that the multitime distribution functions that correspond to Hamiltonian evolution of isolated quantum systems satisfy a certain condition that may be regarded as characterizing a generalized Markov process. We also investigate certain special features of the generalized stochastic processes that characterize the evolution of open systems.
Learning string-edit distance

In many applications, it is necessary to determine the similarity of two strings. A widely-used notion of string similarity is the edit distance: the minimum number of insertions, deletions, and substitutions required to transform one string into the other. In this report, we provide a stochastic model for string-edit distance. Our stochastic model allows us to learn a string-edit distance function from a corpus of examples. We illustrate the utility of our approach by applying it to the difficult problem of learning the pronunciation of words in conversational speech. In this application, we learn a string-edit distance with nearly one-fifth the error rate of the untrained Levenshtein distance. Our approach is applicable to any string classification problem that may be solved using a similarity function against a database of labeled prototypes.
Resolving the sin(I) Degeneracy in Low-mass Multi-planet Systems

Long-term orbital evolution of multi-planet systems under tidal dissipation often converges to a stationary state, known as the tidal fixed point. The fixed point is characterized by a lack of oscillations in the eccentricities and apsidal alignment among the orbits. Quantitatively, the nature of the fixed point is dictated by mutual interactions among the planets as well as non-Keplerian effects. We show that if a roughly coplanar system hosts a hot, sub-Saturn mass planet, and is tidally relaxed, separation of planet-planet interactions and non-Keplerian effects in the equations of motion leads to a direct determination of the true masses of the planets. Consequently, a "snap-shot" observational determination of the orbital state resolves the sin(I) degeneracy and opens up a direct avenue toward identification of the true lowest-mass exoplanets detected. We present an approximate, as well as a general, mathematical framework for computation of the line-of-sight inclination of secular systems, and apply our models illustratively to the 61 Vir system. We conclude by discussing the observability of planetary systems to which our method is applicable and we set our analysis into a broader context by presenting a current summary of the various possibilities for determining the physical properties of planets from observations of their orbital states.
Characteristic Constraint Modes for Component Mode Synthesis

A technique is presented for reducing the size of a model generated by the Craig-Bampton method (Craig, R. R., and Bampton, M. C. C., Coupling of Substructures for Dynamic Analyses, AIAA Journal, Vol. 6, No. 7, 1968, pp. 1313-1319) of component mode synthesis (CMS). An eigenanalysis is performed on the partitions of the CMS mass and stiffness matrices that correspond to the so-called constraint modes. The resultant eigenvectors are referred to as characteristic constraint modes because they represent the characteristic motion of the interface between the component structures. When the characteristic constraint modes are truncated, a CMS model with a highly reduced number of degrees of freedom may be obtained. An example of a cantilever plate is considered. It is shown that relatively few characteristic constraint modes are needed to yield accurate approximations of the lower natural frequencies. Furthermore, this method yields physical insight into the mechanisms of vibration transmission in complex structures, and it provides an excellent framework for the efficient calculation of power flow.
Nevi of Special Sites

Melanocytic nevi can have a wide range of histologic appearances. Within the spectrum of nevi, there exists a group that presents in certain anatomic locations with histologically worrisome features but nonetheless benign behavior. This group of nevi has been broadly categorized as nevi of special sites. The anatomic locations affected by this group include the embryonic milkline (breast, axillae, umbilicus, genitalia), flexural areas, acral surfaces, ear, and scalp. Nevi in these locations may be mistaken for melanomas because of their histologic appearance, resulting in inappropriate overtreatment of patients. In this article, the authors review the histologic features of these special site nevi and discuss the criteria that help distinguish them from melanoma.
Synthesis and Characterization of Amorphous Hydrated Alkali Thio-Hydroxogermanates

The synthesis, structure, and nonhumidified proton conductivity of the hydrated alkali thio-hydroxogermanates, denoted as M x Ges x (OH) 4 - x .yH 2 O (1 < x ≤ 4, 0 < y < 8) for M = Na, K, Rb, and Cs, are reported. These materials are generally X-ray amorphous when produced by a low-temperature (∼75 °C) aqueous solution evaporation-precipitation route. Raman and IR spectroscopies indicate mixed chalcogenide germanium central anions with distinct asymmetric Ge-O and symmetric Ge-S stretching modes observable around 820-754 and 500-325 cm - 1 , respectively. These thio-oxoanions possess a combination of thermally stable hydroxyl groups and hydrophilic alkali associated with the nonbridging sulfurs. Alternating current impendence measurements performed under anhydrous conditions on low-pressure sealed pellets reveal fast ionic conductivity, 10 - 3 -10 - 2 S/cm, for typical temperatures between 100 and 275 °C. The observed falloff in conductivity at higher temperatures is consistent with the appearance of endothermic transitions in differential scanning calorimetry measurements of hermetically sealed samples, presumably from the "boiling" or sublimation of a crystalline water sublattice. Corresponding onset temperatures were observed between 150 and 275 °C and dependent on the alkali and composition. Under dry atmosphere conditions, thermogravimetric analysis mass loss measurements indicate continuous mass loss above the preparation temperature of ∼75 °C.
Stability Criteria for Accelerating and Decelerating Aircraft

Derivation of the linearized differential equation for the longitudinal oscillations of an aircraft for the general case when the atmospheric density, thrust force, and velocity are varying. Exact solutions and stability criteria are presented for several different conditions. For the zero thrust coasting aircraft that is being decelerated by its drag force, new stability criteria are derived for both ascending and descending flight. A critical altitude is found for ascending aircraft that are attempting to coast out of the atmosphere. Above this critical altitude the oscillations cease, and there is a monotonic increase in the angle of attack. Exact solutions for the oscillations of coasting aircraft are presented in terms of the confluent hypergeometric functions. It is shown that previous attempts to predict a critical altitude for ascending vehicles were in error because they did not include the second type, or logarithmic solution, of the confluent hypergeometric function.
Copper-catalyzed oxidative decarboxylative C–H arylation of benzoxazoles with 2-nitrobenzoic acids

A copper-catalyzed oxidative decarboxylative coupling of benzoxazoles with 2-nitrobenzoic acids was developed. This methodology favors electron-rich benzoxazoles and electron-deficient benzoic acids and enables the preparation of a variety of arylated benzoxazoles in good yields. The trends in product yields suggest a delicate balance between the decarboxylation and C–H arylation steps.