cssi/SciSciGPT-SciSciNet huggingface dataset:
Risk-attitude selection bias in subject pools for experiments involving neuroimaging and blood samples

Techniques such as neuroimaging and molecular genetics are increasingly used to investigate economic theory, decision making behavior and personality traits related to economic behavior (e.g., risk attitudes, reward dependence). The generalizability of this research is ultimately limited, however, if the subjects participating in such studies are not representative of the general population with respect to the behavior or traits of interest to the researcher. In this study, university student recruits answer surveys that assess risk attitudes prior to being told that the study involves a one-hour functional magnetic resonance imaging (fMRI) session and a blood sample obtained via phlebotomy. We find recruits with more conservative risk attitudes in two of four measured dimensions are less likely to agree to participate in the study due to these biomedical requirements, suggesting that recruitment among student volunteer populations for fMRI studies and for genetics studies requiring blood as genetic source material may induce a sample selection bias in the domain of risk attitudes. We find that limiting recruitment to individuals who have previously undergone certain types of medical interventions (MRI, computed tomography or surgery) eliminates the sample selection bias in the case of fMRI research and attenuates the bias in the case of genetics research. Furthermore, relying upon buccal cells rather than blood for genetic source material may attenuate sample selection bias. Buccal cell samples can be collected via less invasive oral techniques and have been shown to provide genotyping results that are comparable to blood samples.
Molten salt electrolytes for high-temperature lithium cells

Abstract The composition and melting point of the molten salt electrolyte play a key role in the performance of high-temperature Li-alloy/metal sulfide cells. For example, the performance of the LiAl/FeS cell operated under flooded-electrolyte conditions improves markedly with an increase in the LiCl content of the LiClKCl electrolyte. A similar cell, when operated in a starved-electrolyte state, requires the use of an all-lithium cation electrolyte ( e.g. , LiFLiClLiBr) to achieve good performance. Both these electrolytes have fairly high melting points, >400 °C. The LiAl/FeS 2 cell, on the other hand, has been found to operate well as an upper-plateau cell in an electrolyte (25mol%LiCl–37mol%LiBr–38mol%KBr) with a low melting point, 310 °C. Recent laboratory investigations have also demonstrated that the LiAl/(NiFe)S 2 cell operates very well in an Li 2 S saturated, all-lithium, cation electrolyte at high temperatures, 475 °C.
Quandles and Monodromy

We show that a variety of monodromy phenomena arising in geometric topology and algebraic geometry are most conveniently described in terms of homomorphisms from a(n augmented) knot quandle associated with the base to a suitable (augmented) quandle associated with the fiber. We consider the cases of the monodromy of a branched covering, braid monodromy and the monodromy of a Lefschetz fibration. The present paper is an expanded and corrected version of [1].
Neighboring Optimal Aircraft Guidance in Winds

The technique of Neighboring Optimal Control is extended to handle cases of parameter change in the system dynamic model. This extension is used to develop an algorithm for optimizing horizontal aircraft trajectories in general wind fields using time-varying linear feedback gains. The minimum-time problem for an airplane traveling horizontally between two points in a variable wind field (a type of Zermelo Problem) is used to illustrate how perturbations in system parameters can be accounted for by augmenting the dynamic model with additional bias states. For the special case of a constant wind shear in the cross-track direction, analytical and numerical results are derived for bias perturbations. Numerical simulations are presented to demonstrate the performance of the proposed state-augmentation technique. An additional example is used to demonstrate an algorithm to compute near-optimal trajectories in general wind fields. The algorithm is based on nondimensionalizing the neighboring optimal control solutions and using piecewise linearly varying wind and horizontal wind shear parameters. One proposed application of this technique is to the computation and real-time update of time-optimal trajectories in wind fields by onboard flight management systems and by ground-based air traffic management automation tools.
A model of cultural transmission, voting and political ideology

In this paper, we present a model of cultural transmission of preferences on goods, some of which are provided publicly through simple majority voting. We emphasize the existence of a two-way causality between socialization decisions and political outcomes. This generates the possibility of indeterminacies and multiple self-fulfilling equilibrium paths in cultural change and politics. We provide then a rationale for ideologies and collective socialization institutions as coordination mechanisms allowing cultural groups to preserve or shift political power in favor of their preference profile in the long run.
Revisiting Brightest Cluster Galaxy Evolution with the Las Campanas Distant Cluster Survey

We investigate the influence of environment on brightest cluster galaxy (BCG) evolution using a sample of 63 clusters at 0.3 ≤ z ≤ 0.9 drawn primarily from the Las Campanas Distant Cluster Survey and follow-up V, I, and K' photometry. The luminosity evolution of the entire BCG sample is not adequately described by a single evolutionary model. Using the integrated light from the cluster detection as a proxy for cluster LX and the suggestion by Burke, Collins, & Mann, we set LX = 2 × 1044 ergs s-1 to be the division between high- and low-luminosity clusters. At high redshift (z > 0.6) BCGs from low-LX clusters are fainter, on average, than those from high-LX clusters and are best modeled as having constant luminosity with redshift. The BCGs from high-LX clusters are best modeled as having a stellar population that formed at large redshift (zform > 5) and is passively evolving. However, for the entire BCG population, the observed V-I and I-K' colors are well described by a single evolutionary model in which the stellar populations have zform > 5 and subsequently passively evolve. We conclude that accretion is proportionally more significant for BCGs in lower mass clusters at these redshifts (a factor of 2-4 increase in mass since z ~ 1 for the low-LX systems; Aragon-Salamanca and coworkers) and that the accreted matter is in the form of systems with evolved stellar populations.
Stability of relativistic jets from rotating, accreting black holes via fully three-dimensional magnetohydrodynamic simulations

Rotating magnetized compact objects and their accretion discs can generate strong toroidal magnetic fields driving highly magnetized plasmas into relativistic jets. Of significant concern, however, has been that a strong toroidal field in the jet should be highly unstable to the non-axisymmetric helical kink (screw) m= 1 mode leading to rapid disruption. In addition, a recent concern has been that the jet formation process itself may be unstable due to the accretion of non-dipolar magnetic fields. We describe large-scale fully three-dimensional global general relativistic magnetohydrodynamic simulations of rapidly rotating, accreting black holes producing jets. We study both the stability of the jet as it propagates and the stability of the jet formation process during accretion of dipolar and quadrupolar fields. For our dipolar model, despite strong non-axisymmetric disc turbulence, the jet reaches Lorentz factors of Γ∼ 10 with opening half-angle θj∼ 5° at 103 gravitational radii without significant disruption or dissipation with only mild substructure dominated by the m= 1 mode. On the contrary, our quadrupolar model does not produce a steady relativistic (Γ≳ 3) jet due to mass loading of the polar regions caused by unstable polar fields. Thus, if produced, relativistic jets are roughly stable structures and may reach up to external shocks with strong magnetic fields. We discuss the astrophysical implications of the accreted magnetic geometry playing such a significant role in relativistic jet formation, and outline avenues for future work.
Dynamic buckling of imperfection-sensitive shell structures

Structural buckling under dynamic loads may occur at load levels that are less than the corresponding static loads. Presence of local geometric imperfections may induce an early buckling for both static and dynamic loadings. The phenomenon of "dynamic weakening" is studied for a general class of shell structures under a general class of time-dependent loadings. A doubly curved quadrilateral Love-Kirchhoff shell finite element is used. Geometric deviations of the shell middle surface are included within the element formulation by suitably modifying the strain-displacement relations. This is accomplished by retaining additional terms that are quadratic in spatial derivatives of imperfections and displacement components. The nonlinear equations of motion are written in the Lagrangian system and are solved by using an incremental algorithm based on Newmark's generalized operator. The dynamic responses up to buckling are obtained for a perfect spherical cap and an imperfect spherical cap both under external pressure, as well as a complete imperfect sphere under external pressure. Numerical results include the effects of amplitude of imperfection and thickness of shell on the dynamic buckling loads. The formulation is general and can be applied to obtain the dynamic buckling responses of a wide variety of shell structures.
Investigating the possibility of a human component in various pacific decadal oscillation indices

The pacific decadal oscillation (PDO) is a mode of natural decadal climate variability, typically defined as the principal component of North Pacific sea surface temperature (SST) anomalies. To remove any global warming signal present in the data, the traditional definition specifies that monthly-mean, global-average SST anomalies are subtracted from the local anomalies. Differences in the warming rates over the globe and the PDO region may therefore be aliased into the PDO index. Here, we examine the possibility of a human component in the PDO, considering three different definitions. The implications of these definitions are explored using SSTs from both observations and simulations of historical and future climate, all projected onto (definition-dependent) observed PDO patterns. In the twenty first century scenarios, a systematic anthropogenic component is found in all three PDO indices. Under the first definition—in which no warming signal is removed—this component is so large that it is also statistically detectable in the observed PDO. Using the second/traditional definition, this component is also large, and arises primarily from the differential warming rates predicted in the North Pacific and over global oceans. Removing the spatial average SST signal in the PDO region (in the third definition) partially solves this problem, but a human signal persists because the predicted pattern of SST response to human forcing projects strongly onto the PDO pattern. This illustrates the importance of separating internally-generated and externally-forced components in the PDO, and suggests that caution should be exercised in using PDO indices for statistical removal of “natural variability” effects from observational datasets.
The Development of Iron(II) Complexes as ParaCEST MRI Contrast Agents

Magnetic resonance imaging (MRI) is a powerful imaging modality for visualizing anatomical soft tissue using nonionizing radiation. Compared with other molecular imaging methods such as optical, nuclear, and ultrasound, sensitivity is limited but can be improved through development of chemical agents which enhance MRI contrast. MRI Contrast agents that function through paramagnetic chemical exchange saturation transfer (paraCEST) are currently being investigated as an alternative to T1 and T2 contrast agents. These agents may be designed as imaging probes which are intrinsically responsive to pH and temperature. Trivalentlanthanide complexes have dominated the relatively young field of paraCEST for just over a decade. Recently, high spin FeII complexes containing labile amide and amino protons which chemically exchange with bulk water have emerged as viable additions to the repertoire of paraCEST agents. This microreview will provide an overview of some considerations when designing paraCEST contrast agents which incorporate high spin FeII as the paramagnetic metal center. Important factors such as paramagnetic relaxation and hyperfine shifts, spin state, coordination, oxidation state, and stability will be discussed in regard to transition metal ion paraCEST contrast agent design.
A versatile total synthesis of epibatidine and analogs

A racemic mixture of epibatidine, a potent analgesic alkaloid possessing a 7-azanorbornane structure, has been synthesized via a versatile four-step synthetic route: a Diels-Alder reaction of N-carbomethoxy pyrrole and phenylsulfonyl 6-chloro-3-pyridyl acetylene, followed by desulfonation, hydrogenation and deprotection of the amine. rac -Epibatidine was resolved to its d and l enantiomers.
Ab Initio calculation of band gap renormalization in highly excited GaAs

We present ab initio quasiparticle self-energy calculations in crystalline GaAs for cases of intense electronic excitation $(\ensuremath{\sim}10%$ of valence electrons excited into conduction band), relevant for high-intensity ultrashort pulsed laser experiments. Calculations are performed using an out-of-equilibrium generalization of the $\mathrm{GW}$ approximation based on the Keldysh Green's function approach. Our results indicate that while the quasiparticle band gap is a sensitive function of the amount of excitation, it is not possible to induce complete band-gap closure in this system by purely electronic means.
Rolling-element fatigue life of AMS 5749 corrosion resistant, high temperature bearing steel

The rolling element fatigue lives of AMS 5749 and AISI M-50 were compared in tests run in the five ball fatigue tester and the rolling contact fatigue tester. The effects of double vacuum melting and retained austenite on the life of AMS 5749 were determined in five ball fatigue tests. The double vacuum melting process consisted of induction vacuum melting followed by vacuum arc remelting (VIM-VAR). In the five ball tests, VIM-VAR AMS 5749 gave lives at least six times that of VIM-VAR AISI M-50. Similar tests in the rolling contact fatigue tester showed no significant difference in the lives of the two materials. The rolling element fatigue life of VIM-VAR AMS 5749 was at least 14 times that of vacuum induction melted AMS 5749. A trend toward increased rolling element fatigue life with decreased retained austenite is apparent, but the confidence that all experimental differences are significant is not great.
Comments on 4-point functions in the CFT/AdS correspondence

Abstract We study the four-point function of chiral primaries corresponding to the dilaton–axion sector in supergravity in the AdS5/CFT4 correspondence. We find relations between some of the supergravity graphs and compute their leading singularities. We discuss the issue of logarithmic singularities and their significance for the OPE structure of the CFT.
Self-dual N=(1,0) supergravity in eight dimensions with reduced holonomy Spin(7)

Abstract We construct chiral N=(1,0) self-dual supergravity in Euclidean eight dimensions with reduced holonomy Spin(7), including all the higher-order interactions in a closed form. We first establish the non-chiral N=(1,1) superspace supergravity in eight dimensions with SO(8) holonomy without self-duality, as the foundation of the formulation. In order to make the whole computation simple, and the generalized self-duality compatible with supersymmetry, we adopt a particular set of superspace constraints similar to the one originally developed in ten-dimensional superspace. The intrinsic properties of octonionic structure constants make local supersymmetry, generalized self-duality condition, and reduced holonomy Spin(7) all consistent with each other.
The Translation Operator for Self-Projective Coalgebras

We describe the transpose operator for self-projective and symmetric coalgebras in terms of the syzygy and Nakayama functors.
MAWL: mobile assisted word-learning

Word-learning is one of the basic steps in language learning. A general traditional approach for learning new words is to keep a dictionary and use it whenever one encounters a new word. This video demonstrates Mobile Assisted Word-Learning (MAWL)[1]: an augmented reality based collaborative social-networking interface for learning new words using a smartphone. MAWL keeps track and saves all textual contexts during reading process; along with providing augmented reality-based assistance such as images, translation into native language, synonyms, antonyms, sentence usage etc.
Mechanical engineering's role in multi-disciplinary radar design

Successful execution of a program and full satisfaction of the customer's requirements is a challenge for any contractor. Raytheon Company responds to this challenge by following a proven program execution methodology. The methodology includes all program aspects from financial planning to engineering to validation and test. This discusses the engineering team and the role of the mechanical engineer. A radar system is ultimately an assembly of advanced electronics and software. However, the design, fabrication, assembly, integration, and test Of this complex system requires a coherent multi-disciplinary approach. Raytheon, like many contractors, chooses to assemble an integrated product team (IPT) including all engineering disciplines. Mechanical engineering is integral to satisfying performance requirements, performing preliminary and detailed design, transition of the design to manufacturing, and implementation of the hardware in the field. During definition, mechanical engineering assists fundamental architecture development, conceptual design, and requirements development which precludes issues that are sometimes ignored to the detriment of many programs. These design issues include environmental protection, structural stiffness to meet deflection requirements, cooling system capacity to properly remove dissipated heat, manufacturability to control cost, maintainability to enable repair in the field, and transportability. Recognizing and trading off these issues early greatly increases the Probability Of satisfying customer objectives. This discusses the approach Raytheon is taking to ensure an overall multi-disciplinary solution to our design challenges from the perspective of the mechanical engineer.
Cryogenic operation of asymmetric n-channel IGBTs

Abstract Detailed experimental data taken for asymmetric n-channel IGBTs between 300 and 77 K are presented. The forward voltage drop, the gain of the inherent PNP transistor and turn off time were found to decrease whereas the threshold voltage and transconductance were found to increase with a decrease in operating temperature. This paper provides analytical models for the behavior of these parameters. Based upon this study, a much lower on-state and switching power loss is predicted for IGBTs operated at cryogenic temperatures.
Hardy-Sobolev-Maz'ya inequalities for arbitrary domains

We prove a Hardy-Sobolev-Maz’ya inequality for arbitrary domains Ω ⊂ R^N with a constant depending only on the dimension N ≥ 3. In particular, for convex domains this settles a conjecture by Filippas, Maz’ya and Tertikas. As an application we derive Hardy-Lieb-Thirring inequalities for eigenvalues of Schrodinger operators on domains.
The Shape of the Galaxy

There is growing evidence that our Galaxy is a complex triaxial system. In this article, I will present evidence that the disk of the Galaxy is not axisymmetric and conclude by discussing the implications of its triaxiality for galaxy formation and evolution.
High-pressure proton disorder in brucite

In this paper we explore the structure and physical properties of brucite over a wide range of pressures with density functional theory using the variable cell-shape plane wave pseudopotential method in the local density (LDA) and generalized gradient (GGA) approximations. We probe the energetics underlying the structure and dynamics of the proton sub-lattice by performing a series of constrained and unconstrained static calculations based on an energetically stable root 3x root 3x1 super-cell wherein proton locations are related to the 6i Wyckoff sites as opposed to the ideal 2d site. The displacement of the hydrogen atom from the threefold axis increases with increasing pressure. This means that even in the absence of thermal energy, the protons are frustrated and would be expected to exhibit long-range disorder akin to a spin glass. To shed light on the dynamic nature of the proton hopping between the 6i-like sites, we determined the activation energy barrier for such jumps. We found that the energy barrier increases with compression, possibly indicating a transition from dynamic proton disorder at lower pressures to static disorder at higher pressure. We have also investigated the possibility of proton jumps across the interlayer, by determining the potential energy well along the O center dot center dot center dot O vector. We infer that proton jumps across the interlayer are either severely limited or highly cooperative since we did not find any evidence for a double well along the O center dot center dot center dot O vector. The absence of a double well along the O center dot center dot center dot O vector, the evolution of O-H center dot center dot center dot O distances with compression, and the gradual transition to a symmetric O-H center dot center dot center dot O configuration, all argue for weak hydrogen bonding in brucite.
The Term Structure of Interest Rates: Alternative Approaches and Their Implications for the Valuation of Contingent Claims

One of the most active areas of research in financial economics has been the modeling of the term structure of interest rates and its relationship to the pricing of contingent claims. There is a vast array of issues in the area, as well as a variety of perspectives, ranging from theoretical to practical. This article provides a general framework for the analysis of issues in the modeling of the term structure. Specifically, this article provides an overview of the conceptual issues and the empirical evidence in the area, based on an examination of five seminal models by Black, Scholes, and Merton; Vasicek; Cox, Ingersoll, and Ross; Ho and Lee; and Heath, Jarrow, and Morton. The article provides a synthesis of the area and suggests directions for future research.
Reduction of amides with NaBH4 in diglyme at 162°C

High temperature (162°C) reductions of aromatic amides were studied to extend the useful range of functional group transformations by NaBH4. Primary aromatic amides were reduced to the amines with NaBH4–diglyme at 162°C. Reduction proceeds via fast initial loss of hydrogen, followed by formation of the corresponding nitrile, which is then more slowly reduced to the amine. N-Methylbenzamide is not reduced under these conditions, but it is reduced to benzylmethylamine when LiCl is added to NaBH4–diglyme at 162°C. LiCl addition raised the rate of primary aromatic amide and aromatic nitrile conversions to both the nitrile, first, and the amine. An intermediate was isolated from the reaction of N-benzylformamide with NaBH4–LiCl in diglyme at 162°C. It was examined by 1H NMR, atomic absorption, IR and thermal decomposition. Possible structures are proposed. A mechanism for the reduction of primary aromatic amides is proposed based on the initial evolution of one mole equivalent of hydrogen and formation of the nitrile prior to further reduction to amine.
Direct Semiparametric Estimation of Single-Index Models with Discrete Covariates

Abstract Others have developed average derivative estimators of the parameter β in the model E(Y|X = x) = G(xβ), where G is an unknown function and X is a random vector. These estimators are noniterative and easy to compute but require that X be continuously distributed. This article develops a noniterative, easily computed estimator of β for models in which some components of X are discrete. The estimator is n ½ consistent and asymptotically normal. An application to data on product innovation by German manufacturers illustrates the estimator's usefulness.
New diol metabolites derived by biooxidation of chlorostyrenes with Pseudomonas putida : determination of absolute stereochemistry and enantiomeric excess by convergent syntheses

Abstract The three isomers of chlorostyrenes were subjected to whole cell biooxidation by means of a mutant strain of Pseudomonas putida 39D. The metabolites were isolated and their absolute stereochemistry determined by conversion to known standards derived from 1-ethenyl-2,3-dihydroxycyclohexa-4,6-diene whose absolute configuration has been previously established. The extent of ring vs side chain oxidation of the chlorostyrene isomers was evaluated and the enantiomeric excess determined for all compounds.
Understanding Privacy Online: Development of a Social Contract Approach to Privacy

Recent scholarship in philosophy, law, and information systems suggests that respecting privacy entails understanding the implicit privacy norms about what, why, and to whom information is shared within specific relationships. These social contracts are important to understand if firms are to adequately manage the privacy expectations of stakeholders. This paper explores a social contract approach to developing, acknowledging, and protecting privacy norms within specific contexts. While privacy as a social contract—a mutually beneficial agreement within a community about sharing and using information—has been introduced theoretically and empirically, the full impact on firms of an alternative framework to respecting the privacy expectations of stakeholders has not been examined. The goal of this paper is to examine how privacy norms develop through social contract’s narrative, to redescribe privacy violations given the social contract approach, and to critically examine the role of business as a contractor in developing privacy norms. A social contract narrative dealing specifically with issues of privacy is an important next step in exploring a social contract approach to privacy. Here, the narrative is used to explain to analyze the dynamic process of privacy norm generation within particular communities. Based on this narrative, individuals within a given community discriminately share information with a particular set of obligations in mind as to who has access to the information and how it will be used. Rather than giving away privacy, individuals discriminately share information within a particular community and with norms governing the use of their information. Similar to contractual business ethics’ impact on global commerce in explaining how and why norms vary across global contexts, the social contract approach to privacy explains how and why norms vary across communities of actors. Focusing on agreements around privacy expectations shifts the responsibility of firms from adequate notification to the responsibility of firms as contractors to maintain a mutually beneficial and sustainable solution.
Manufacturing all-polymer laminar flow-based fuel cells

Abstract On the macroscale, fuel cell systems typically require heavy clamping constructions to seal layers. Here we report an alternative manufacturing approach that utilizes patterned polymer layers to yield much thinner, lighter laminar flow-based fuel cells (LFFCs). Most LFFCs reported to date have been proof-of-concept configurations. To meet the power requirements of portable electronic devices, challenges related to the design and manufacturing of scalable LFFC systems still need to be addressed. Here we report electrodes that are encapsulated between polymer layers with metallized polymer layers serving as current collectors. Assembly of a polymer-encapsulated anode and cathode yields a 1-mm thick all-polymer fuel cell, about one order of magnitude thinner than most microfluidic fuel cells. To identify performance changes associated with this alternative approach to electrode and catalyst integration, we first validated performance by analyzing the polymer-encapsulated anodes and cathodes individually, and then the complete cell after bonding the polymer-encapsulated electrodes together. This all-polymer fuel cell achieved a maximum power density of 10 mW cm−2 at room temperature when using 1 M methanol as the fuel. Thin, lightweight fuel cell stacks for future portable power applications could be obtained by scaling and stacking of the all-polymer cell reported here.
A Half‐Century Odyssey in the Realm of Reactive Intermediates

Through a retrospective examination of the author’s half-century immersion in physical organic chemistry, an attempt is made to identify some broader currents in the field. Among these are the cyclical nature of physical organic chemistry, the persistence of research themes, the driving force of new instrumentation, paradigm shifts in theory, greater computational power, enhanced time resolution of experiments, and the export of mechanism-based analysis to other foci of contemporary science.
Approximate solutions for large transfer matrix problems

A new approach is proposed for the determination of the dominant eigenvalues and their corresponding eigenvectors for one-spin transfer matrices. The matrices describe properties of spin systems on semi-infinite lattices. The method gives approximate solution for lattices of widths larger than previously tractable.
Population studies of the unidentified EGRET sources

The third EGRET catalog contains a large number of unidentified sources. This subset of objects is expected to include known gamma-ray emitters of Galactic origin such as pulsars and supernova remnants, in addition to an extragalactic population of blazars. However, current data allows the intriguing possibility that some of these objects may represent a new class of yet undiscovered gamma-ray sources. Many theoretically motivated candidate emitters (e.g. clumps of annihilating dark matter particles) have been suggested to account for these detections. We take a new approach to determine to what extent this population is Galactic and to investigate the nature of the possible Galactic component. By assuming that galaxies similar to the Milky Way should host comparable populations of objects, we constrain the allowed Galactic abundance and distribution of various classes of gamma-ray sources using the EGRET data set. We find it is highly improbable that a large number of the unidentified sources are members of a Galactic halo population, but that a distribution of the sources entirely in the disk and bulge is plausible. Finally, we discuss the additional constraints and new insights that GLAST will provide.
Ripple-Port Module-Integrated Inverter for Grid-Connected PV Applications

The single-phase inverter has inherent double-frequency power ripple, which if not internally mitigated, appears at the input port and deteriorates the maximum power point tracker performance. Conventional dc link inverter topologies filter this significant double-frequency ripple by means of the bus capacitance, usually in the form of electrolytic capacitors, which have well known lifetime challenges. This paper presents a double-frequency ripple cancellation concept and experimental proof of concept. The proposed module-integrated inverter is based on the commonly used two-stage inverter. However, a third port is added for ripple cancellation purposes. Hence, a very small capacitance is needed, and, as a result, a high-reliability film capacitor can be used instead of the bulky low-reliability electrolytic ones.
Planning for the Transportation Needs of Welfare Participants: Institutional Challenges to Collaborative Planning

The responsibility for developing transportation programs for welfare participants spans multiple public agencies. Consequently, federal funding programs require that agencies work together to develop a coordinated response to addressing the transportation needs of welfare participants. Based on a survey of transportation, welfare and employment agencies in 19 California counties, this study examines the potential institutional obstacles to successful local collaboration and coordination among public agencies. The research shows that new sources of federal funds have encouraged interagency efforts to address the transportation needs of welfare participants. However, the divergent organizational goals, methods, and approaches of the participating agencies heavily influence these collaborative efforts. As a consequence, stakeholders may have difficulty moving beyond the narrow interests of their individual institutions to identify and plan for the transportation needs of welfare participants.
Tau physics 1994 — A theoretical perspective*

In this paper I describe some recent advances in tau physics and discuss their implications from a theoretical perspective. The examples I have chosen include e-{mu}-{tau} universality, QCD studies, anomalous electroweak dipole moments, and forbidden decays. That list is by no means exhaustive. It should, however, demonstrate the breath of tau physics, describe some interesting new results, and point out the potential for future advances.
TOTAL SYNTHESIS OF (±)-FUSARICIDE

Condensation of pyridone 6 with enal 25 using DMAP in EtOH at 150°C afforded 8% of the desired Diels-Alder adduct 22, 8% of the bridged adduct 36 and 1–2% of a partially pure cis-fused adduct 37 of unknown stereochemistry. Hydroxylation of 22 completed a short synthesis of fusaricide (1).
Endosonographic assessment of multimodality therapy predicts survival of esophageal carcinoma patients

BACKGROUND Standard endosonographic (EUS) staging criteria are unreliable for staging esophageal carcinoma after neoadjuvant therapy; however, measurement of tumor size reduction can identify patients who have achieved a pathologic response. In the current study the authors prospectively compared survival between patients classified as responders and those classified as nonresponders by EUS. METHODS The maximal transverse cross-sectional area of the tumor was measured before and after neoadjuvant therapy in patients who were candidates for multimodality treatment. Response was defined as a ≥ 50% reduction in tumor area. RESULTS A total of 59 patients at 2 centers were followed for a median of 19 months. EUS assessed response in 34 patients (58%). Overall, responders had a median survival of 17.6 months compared with 14.5 months for nonresponders (P < 0.005). Survival was significantly longer in responders compared with nonresponders in the patient subgroup who underwent surgical resection (19.7 months vs. 14.6 months; P < 0.005), the patient subgroup with adenocarcinoma (21.4 months vs. 10.8 months; P < 0.005), and the patient subgroup initially classified as having T3N1 disease (17.6 months vs. 14.1 months; P < 0.05). Survival was not found to differ significantly between responders and nonresponders in the subgroup of patients with squamous cell carcinoma. EUS response was the only clinical variable that was associated with survival time in a multivariate analysis (relative hazard = 0.27; P < 0.005). CONCLUSIONS Patients with esophageal carcinoma who respond to neoadjuvant treatment as identified by EUS measurement of reduction in tumor size have a significantly better prognosis than nonresponders. Cancer 2000;88:1788–95. © 2000 American Cancer Society.
The Welfare Implications of Increasing Disability Insurance Benefit Generosity

Abstract In order to evaluate whether workers are over- or under-insured through the Disability Insurance (DI) program, we develop a framework that allows us to simulate the benefits as well as the costs associated with marginal changes in payment generosity from a representative cross-sectional sample of the population. Under the assumption that individuals are reasonably risk averse, we find that the typical worker would value increased benefits somewhat above the average costs of providing them. However, whether the benefit increases tend to lower or raise utility when we average across all individuals in our sample is sensitive to assumptions that affect the relative marginal utility of income to disabled individuals.
RECENT PROGRESS IN THE SYNTHESIS, PROPERTIES AND REACTIONS OF TRISULFANES AND THEIR OXIDES

(1998). RECENT PROGRESS IN THE SYNTHESIS, PROPERTIES AND REACTIONS OF TRISULFANES AND THEIR OXIDES. Organic Preparations and Procedures International: Vol. 30, No. 5, pp. 551-600.
Ensuring the Survival of the Clinician–Scientist

Many forces threaten the survival of the clinician-scientist as an academic species, among them: (1) the changing health environment; (2) the complexity of and rapid advances in biomedical science, which necessitate that MD-PhD graduates "retool" after completing their clinical training; (3) the length and rigor of the research training required to train clinician-scientists adequately; (4) the scarcity of funding for subspecialty training positions; (5) the perception that the successful clinician-scientists in academic medicine are those who focus on basic, rather than clinical, research; (6) the indebtedness of young physicians when they complete medical schools; (7) the fierce competition for research funding; and (8) pessimism among senior faculty about the clinician-scientist's potential for survival. There are solutions to these issues that must be vigorously pursued to ensure the survival of the clinician-scientist: (1) Rigorous six- to seven-year programs (e.g., two in internal medicine, four to five in a subspecialty) for physicians must be established. They should include a minimum of three years of research and should lead to board certification in internal medicine, pediatrics, psychiatry, etc., board certification in a subspecialty, and a PhD in clinical science. (2) These programs must have a choice of three tracks, (a) disease-oriented basic research, (b) clinical investigation in patients, and (c) health services research. Such a program--the PhD in Clinical Science program--has recently been approved and begun at the University of Colorado. (3) Funding organizations such as the National Institutes of Health should designate their training resources primarily for programs with a minimum of three years of formal and rigorous research training. (4) These rigorous research training programs must be integrated with young-faculty awards for clinician-scientists to ensure continuity in their investigative careers. (5) Loan-repayment programs must be developed to repay student loans of clinician-scientists during their first five years as faculty members. (6) Against the background of these changes, senior faculty as mentors must articulate to emerging clinician-scientists the excitement of being involved in future discoveries in biomedical science.
A TASK DECOMPOSITION APPROACH TO USING NEURAL NETWORKS FOR THE INTERPRETATION OF BIOPROCESS DATA

Abstract During the course of most bioproccss development programs a large amount of process data is generated and stored. However, while these data records contain important information about the process, little or no use is made of this asset. The work described here uses a neural network approach to “learn” to recognize patterns in fermentation data. Neural networks, trained using fermentation data generated from previous runs, are then used to interpret data from a new fermentation. We propose a task decomposition approach to the problem. The approach involves decomposing the problem of bioprocess data interpretation into specific tasks. Separate neural networks are trained to perform each of these tasks which include fault diagnosis, growth phase determination and metabolic condition evaluation. These trained networks are combined into a multiple neural network hierarchy for the diagnosis of bioprocess data. The methodology is evaluated using experimental data from fed-batch, Saccharomyces cerevisiae fermentations. We argue that the task decomposition approach taken here allows for each network to develop a task specific representation and that this in turn, can lead to network activations and connection weights that are more clearly interpretable. These expert networks can now be pruned to remove nodes that do not contribute significant additional information.
Applications of time-frequency processing to radar imaging

Due to the time-varying behavior of the Doppler frequency of radar returns, and due to the multiple backscattering behavior of radar targets, the resolution of radar images can be significantly degraded and those images may be blurred. Conventional radar processors use the Fourier transform to retrieve Doppler information. To use the Fourier transform properly, some restrictions must be applied: the scatterers must remain in their range cells and their Doppler frequency shifts should be stationary during the entire imaging time. However, due to a target’s complex motion, the Doppler frequency shifts will be timevarying. Therefore, the Doppler spectrum obtained from the Fourier transform will be smeared, and, the radar image will be blurred. However, the restrictions of the Fourier transform can be lifted if the Doppler information is retrieved with a time-frequency transform that does not require a stationary Doppler spectrum. The image blurring problem caused by time-varying Doppler frequency shifts can be solved without resorting to sophisticated motion-compensation techniques. By replacing the conventional Fourier transform with a time-frequency transform, a 2-D range-Doppler Fourier frame becomes a 3-D time-range-Doppler cube. By sampling in time, a time sequence of 2-D range-Doppler images can be viewed. Individual, time-sampled images from the cube provide superior image resolution. When targets contain cavities or ducttype structures, these structures’ scattering mechanisms appear in radar images as blurred ‘‘clouds’’ extending in range. It is beneficial to incorporate the time-frequency transform into range profiles of the radar image. By so doing ‘‘clouds’’ can be removed and structure resonance frequencies identified.
The Moduli Space of Riemann Surfaces of Large Genus

Let $${\mathcal{M}_{g,\epsilon}}$$ be the $${\epsilon}$$ -thick part of the moduli space $${\mathcal{M}_g}$$ of closed genus g surfaces. In this article, we show that the number of balls of radius r needed to cover $${\mathcal{M}_{g,\epsilon}}$$ is bounded below by $${(c_1g)^{2g}}$$ and bounded above by $${(c_2g)^{2g}}$$ , where the constants c 1, c 2depend only on $${\epsilon}$$ and r, and in particular not on g. Using this counting result we prove that there are Riemann surfaces of arbitrarily large injectivity radius that are not close (in the Teichmuller metric) to a finite cover of a fixed closed Riemann surface. This result illustrates the sharpness of the Ehrenpreis conjecture.
Integrated vertical parallel-plate capacitive humidity sensor

A high sensitivity capacitive chemical vapor sensing topology, a vertical parallel-plate sensor, was successfully integrated with CMOS testing electronics. The sensor was fabricated by etching a sacrificial aluminum layer in the CMOS stack and filling the resulting cavity with polyimide. The measured humidity response is a 0.31% change in capacitance per percent relative humidity. The temperature sensitivity of the sensor, an important specification for a sensor exposed to a variety of environmental conditions, is 0.19% °C−1. The rising and falling response time constants for a change in relative humidity are 70 and 85 s, respectively. The minimum detectable signal is 0.06 fF, corresponding to a limit of detection of 0.0023% relative humidity.
Advanced-multi-step nonlinear model predictive control

Abstract Nonlinear model predictive control (NMPC) has gained widespread attention due to its ability to handle variable bounds and deal with multi-input, multi-output systems. However, it is susceptible to computational delay, especially when the solution time of the nonlinear programming (NLP) problem exceeds the sampling time. In this paper we propose a fast NMPC method based on NLP sensitivity, called advanced-multi-step NMPC (amsNMPC). Two variants of this method are developed, the parallel approach and the serial approach. For the amsNMPC method, NLP problems are solved in background multiple sampling times in advance, and manipulated variables are updated on-line when the actual states are available. We present case studies about a continuous stirred tank reactor (CSTR) and a distillation column to show the performance of amsNMPC. Nominal stability properties are also analyzed.
Practical Methods for Predicting Aerodynamic Heating Effects on Sounding Rockets

Sounding rockets aerodynamic heating effects approximate prediction methods using computer programs
Trivial spectrum of free 1 + 1 light-cone strings

Abstract The BRST cohomology of 1 + 1 strings in a free light-cone gauge contains only the two-dimensional tachyon, and excludes all excited states of both matter and ghosts, including the special states that arise in the continuum conformal gauge quantization and in the c = 1 matrix models. This exclusion takes plase at a very basic level, and therefore may signal some serious problems or at least unresolved issues involved in this gauge choice.
Some improved bounds on the information rate of perfect secret sharing schemes

In this paper we study secret sharing schemes for access structures based on graphs. A secret sharing scheme enables a secret key to be shared among a set of participants by distributing partial information called shares. Suppose we desire that some specified pairs of participants be able to compute the key. This gives rise in a natural way to a graphG which contains these specified pairs as its edges. The secret sharing scheme is calledperfect if a pair of participants corresponding to a nonedge ofG can obtain no information regarding the key. Such a perfect secret sharing scheme can be constructed for any graph. In this paper we study the information rate of these schemes, which measures how much information is being distributed as shares compared with the size of the secret key. We give several constructions for secret sharing schemes that have a higher information rate than previously known schemes. We prove the general result that, for any graphG having maximum degreed, there is a perfect secret sharing scheme realizingG in which the information rate is at least 2/(d+3). This improves the best previous general bound by a factor of almost two.
A High-Order Kernel Method for Diffusion and Reaction-Diffusion Equations on Surfaces

In this paper we present a high-order kernel method for numerically solving diffusion and reaction-diffusion partial differential equations (PDEs) on smooth, closed surfaces embedded in \(\mathbb{R }^d\). For two-dimensional surfaces embedded in \(\mathbb{R }^3\), these types of problems have received growing interest in biology, chemistry, and computer graphics to model such things as diffusion of chemicals on biological cells or membranes, pattern formations in biology, nonlinear chemical oscillators in excitable media, and texture mappings. Our kernel method is based on radial basis functions and uses a semi-discrete approach (or the method-of-lines) in which the surface derivative operators that appear in the PDEs are approximated using collocation. The method only requires nodes at “scattered” locations on the surface and the corresponding normal vectors to the surface. Additionally, it does not rely on any surface-based metrics and avoids any intrinsic coordinate systems, and thus does not suffer from any coordinate distortions or singularities. We provide error estimates for the kernel-based approximate surface derivative operators and numerically study the accuracy and stability of the method. Applications to different non-linear systems of PDEs that arise in biology and chemistry are also presented.