cssi/SciSciGPT-SciSciNet huggingface dataset:
Multi-Robot Assembly Sequencing via Discrete Optimization

Multi-robot assembly has the potential to greatly reduce the cost and risk associated with the fabrication of large structures. Using teams of robots to perform assembly offers numerous advantages such as parallelism, robustness to single-agent failures, and flexibility in scheduling and task assignment. However, while previous work on multi-robot assembly focuses on generating feasible assembly plans and decentralized control strategies, we instead study the problem of planning optimal assembly sequences.To this end, we pose the problem of multi-robot assembly as a discrete optimization, specifically an integer linear program (ILP) or quadratic program (IQP), which aims to minimize the time to complete the assembly, or to minimize the distance traveled. We develop a model of multi-robot assembly that captures both geometric constraints and actuation constraints inherent to the problem. While the ILP and IQP can be solved exactly using commercial optimization software in a substantial amount of time, we also propose heuristic strategies which can be quickly computed, and can scale to structures of reasonable size. We also verify our methods empirically by comparing their performance on a variety of test structures.
Investigation of startup, performance and cycling of a residential furnace integrated with micro-tubular flame-assisted fuel cells for micro-combined heat and power

Abstract Solid Oxide Fuel Cells (SOFCs) offer advantages for micro-Combined Heat and Power (μCHP), but currently suffer from slow startup (>1 h) and limited thermal cycling which reduces the applications, energy savings and economics. In this work, a micro-Tubular SOFC stack is integrated into a residential furnace to create a micro-Tubular Flame-assisted Fuel Cell (mT-FFC) μCHP system. A high power density of 202 mW cm−2 is reported operating in synthesis gas generated from fuel-rich combustion of natural gas/air. Unlike previous reports, instabilities in the polarization are attributed to low temperature of the oxygen reduction reaction at the cathode. The mT-FFC stack achieved peak power density in 6 min after ignition. 200 thermal cycles at an average heating rate of 215 °C.min−1 and average cooling rate of 176 °C.min−1 were conducted and a low degradation rate of 0.0325 V per 100 cycles per fuel cell was achieved. Low NOx emissions (10 ppm) and high combined efficiency is reported.
The effects of trade deficit on output and employment: evidence from the U.S.’s economy

This paper investigates the effect a trade deficit has on GDP in the United States and if the effect is being lessened by the income and substitution effect. Employment will also be discussed in this paper as regression and cointegration analysis will be used to see what effect technology and the trade deficit have on employment in the manufacturing sector. The results suggest that trade deficit has a small negative effect on GDP. In addition, we find that technology advancement has more impact on employment than the trade deficit.
Reactive Transport Modeling of Shale–Fluid Interactions after Imbibition of Fracturing Fluids

Injection of hydraulic fracturing fluid (HFF) into shale formations for unconventional oil/gas production results in chemical reactions in the shale matrix. Our recent experimental study determined...
Recent developments in single-photon detection with superconducting nanowires (Conference Presentation)

Superconducting nanowires are currently a key technology for photon sensing, with key performance metrics exceeding those of most competing technologies. For example, recently detector timing resolution of just 3 ps for single visible photons was demonstrated. In addition, infrared sensitivity has long been a key advantage of these techniques. But the field continues to change rapidly, with interesting architectures emerging that promise increased functionality in the same form factor. For example, imaging, photon-number-resolution, and spectroscopy are all promising directions the field is now pursuing. In this review, I will explain the technology, applications, and background device physics, but also touch on some of the latest new developments.
Husserl’s Transcendental Turn

The term ‘transcendental’ refers to a wide variety of philosophical approaches which draw their inspiration, however remotely, from Kant’s decision to search for the foundations of rationality in the a priori structures of the experiencing subject. Although there has been considerable debate in the subsequent tradition about the status of subjectivity, transcendental philosophers agree that the principal source for an investigation into human rationality is provided by the subject’s deductive or reflective access to its own invariant operations and structures. Husserl uses the term ‘transcendental’ to refer to the unique status of rationality, to the philosophical attitude that permits appropriate thinking about the relationship between knower and known, and to the method and language of the philosopher engaged in such thinking. Like Kant, he claims that such thinking takes place within a universal zone of intelligibility, which he often describes as a plane or dimension which cannot be located within the coordinates of the empirical world. He also characterizes his version of transcendental philosophy as the fulfillment of the original project of Greek philosophy. Referring to his first intimation of the interplay between transcendental and empirical dimensions, he even goes so far as to say that it had been given to him “to see what had never before been seen, to think what had never before been thought.”1
Persistent Hypertransmission Defects on En Face OCT Imaging as a Stand-Alone Precursor for the Future Formation of Geographic Atrophy.

Purpose To evaluate the prognostic significance of persistent choroidal hypertransmission defects (HyperTDs) detected on en face OCT imaging for predicting the progression of drusen to geographic atrophy (GA) by analyzing their association with the presence of nascent GA (nGA). Design Retrospective, post hoc subgroup analysis of a prospective study. Participants Patients with bilateral soft drusen from a natural history study. Methods Participants underwent both Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany) and Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA) imaging over 36 months at 6-month intervals. The Spectralis SD-OCT B-scans were used to grade nGA. En face imaging of Cirrus SD-OCT scans was used to detect HyperTDs, masked to nGA gradings. Hypertransmission defects with greatest linear dimension (GLD) of 125 μm or more were tracked throughout visits. Main Outcome Measures The GLD at baseline for best discrimination between persistent and transient HyperTDs over 36 months and the association between these HyperTDs with nGA assessed with odds ratio. Results A total of 157 eyes from 81 patients were enrolled. Cirrus SD-OCT scans were available for 133 eyes at baseline, and 39 HyperTDs lesions from 27 eyes of 22 participants were classified as either persistent (26 lesions) or transient (13 lesions) over 36 months. Receiver operating characteristic curve analysis suggested that HyperTDs with baseline GLD of 250 μm or more or 300 μm fit the definition of persistent. After grading the entire population of 157 eyes, a significant association (P Conclusions Choroidal HyperTDs on en face OCT imaging were associated strongly with nGA. The potential of using HyperTDs with GLD of 250 μm or more or 300 μm as a risk factor for the progression of drusen to GA is promising and requires further study.
A Profile of Multidimensional Poverty in America

Applying the Alkire-Foster method to data from the 2008–2018 American Community Surveys, we calculate the Multidimensional Poverty Index (MPI) for the U.S. as the product of the incidence and intensity of deprivation. Incidence is represented by the headcount ratio (i.e., the proportion of the population that is classified as multidimensionally poor), while intensity is represented by the average deprivation intensity value (i.e., the mean deprivation score among those who suffer multidimensional poverty). Documenting multidimensional poverty in the U.S. at the national level, we estimate that in the typical year during our reference period, 25,328,644 U.S. residents were multidimensionally poor. This is equivalent to 8.01 percent of the country’s population. We also produce corresponding estimates for four segments of the population: those who are neither multidimensionally poor nor vulnerable to multidimensional poverty, those who are vulnerable to multidimensional poverty, those experiencing moderate multidimensional poverty, and those who face severe multidimensional poverty. Further, we estimate the frequency of deprivation at the dimension and indicator levels of detail. To demonstrate the robustness of our MPI measure, we close the chapter by comparing several alternative constructions of the MPI and the associated incidence and intensity series to our primary measure.
Pediatric Pain Screening Tool: A Simple 9-Item Questionnaire Predicts Functional and Chronic Postsurgical Pain Outcomes After Major Musculoskeletal Surgeries

Abstract Reliable, clinic-friendly screening for Chronic postsurgical pain (CPSP) risk is unavailable. Within a prospective, observational study, we evaluated Pediatric Pain Screening Tool (PPST), a concise 9-item questionnaire, as a preoperative screening tool to identify those at higher risk for CPSP (Numerical Rating Scale > 3/10 beyond 3 months post-surgery) and poor function (disability/Functional Disability Inventory [FDI]/quality of life/ Pediatric Quality of Life) after spine fusion and Nuss procedures. Incidence of CPSP was 34.86% (38/109). We confirmed PPST scale stability, test re-test reliability (ICC = 0.68; P ClinicalTrials.gov Identifier NCT02998138 . Perspective The article supports Pediatric Pain Screening Tool, a simple 9-item questionnaire, as a preoperative screening tool for CPSP and function 6-12 months after spine/pectus surgeries. PPST measures correlate with known risk factors for CPSP. Risk stratification and targeted preventive interventions in high-risk subjects are proposed.
Event-related alpha perturbations related to the scaling of steering wheel corrections

Previously we derived a new measure relating the driver's steering wheel responses to the vehicle's heading error velocity. This measure, the relative steering wheel compensation (RSWC), changes at times coincident with an alerting stimulus, possibly representing shifts in control strategy as measured by a change in the gain between visual input and motor output. In the present study, we sought to further validate this novel measure by determining the relationship between the RSWC and electroencephalogram (EEG) activity in brain regions associated with sensorimotor transformation processes. These areas have been shown to exhibit event-related spectral perturbation (ERSP) in the alpha frequency band that occurs with the onset of corrective steering wheel maneuvers in response to vehicle perturbations. We hypothesized that these regions would show differential alpha activity depending on whether the RSWC was high or low, reflecting changes in gain between visual input and motor output. Interestingly, we find that low RSWC is associated with significantly less peak desynchronization than larger RSWC. In addition we demonstrate that these differences are not attributable to the amount the steering wheel is turned nor the heading error velocity independently. Collectively these results suggest that neural activity in these sensorimotor regions scales with alertness and may represent differential utilization of multisensory information to control the steering wheel.
Basis Expansions and Regularization

We have already made use of models linear in the input features, both for regression and classification. Linear regression, linear discriminant analysis, logistic regression and separating hyperplanes all rely on a linear model. It is extremely unlikely that the true function f(X) is actually linear in X. In regression problems, f(X) = E(Y|X) will typically be nonlinear and nonadditive in X, and representing f(X) by a linear model is usually a convenient, and sometimes a necessary, approximation. Convenient because a linear model is easy to interpret, and is the first-order Taylor approximation to f(X). Sometimes necessary, because with N small and/or p large, a linear model might be all we are able to fit to the data without overfitting. Likewise in classification, a linear, Bayes-optimal decision boundary implies that some monotone transformation of Pr(Y = 1|X) is linear in X. This is inevitably an approximation.
A study of the polarization of light scattered by vegetation

This study was undertaken in order to better understand the factors that govern the polarization of light scattered from vegetation and soils. The intensity and polarization of light scattered by clover and grass in vivo and soil were measured at a number of different angles of incidence and reflectance. Both individual leaves and natural patches of leaves were measured. The light transmitted through the leaves was found to be negatively polarized. The light scattered from the upper leaf surface was found to be positively polarized in a manner which could be accounted for qualitatively but not quantitatively by the Fresnel reflection coefficients modified by a shadowing function of the form cos sup2 (g/2), where g is the phase angle. Findings indicate that the polarization of light scattered by vegetation is a more complex process than previously thought, and that besides the surface-scattered component of light, the volume-scattered and multiply-scattered components also contribute significantly to the polarization.
Hydrogen metabolism in Escherichia coli: biochemical and genetic evidence for a hydF gene.

Abstract A new gene whose product is essential for production of all three hydrogenase isoenzymes in Escherichia coli has been identified. This gene, termed hydF, mapped at 59 min in the E. coli chromosome and resided next to the hydB gene. The map order of these genes was hydE, hydF, hydB, fhlA, and fdv. The hydF gene was transcribed from its own promoter and coded for a protein with an apparent molecular weight of 43,000 to 44,000. Expression of the hydF operon was enhanced by anaerobic growth conditions. Partial products of the hydF gene were capable of supporting various levels of hydrogenase activity in a hydF mutant in the presence of the fhlA gene product, also produced from multicopy plasmids. In the presence of a second mutation in an unidentified, unlinked gene, hydrogenase activity in a hydF mutant was restored by plasmids which carried incomplete hydF and hydB+ genes. These results suggest that the products of hydF and fhlA interact with each other and with yet one other gene product.
Unique polyethylene morphologies produced under extrusion conditions

Unusual morphologies have been shown to be produced in high density polyethylene near its melting point and under selective conditions of orientation and pressure existing in an Instron capillary extrusion rheometer. Points of study involve the remarkably high optical clarity and tensile moduli for the morphologies produced in these filaments. Details of the crystallization procedure are provided. The morphologies resulting from the Instron procedure have been analyzed by several different techniques. X-ray, calorimetry, microscopy and modulus data are discussed. The transparent filaments are composed of a large number of microfibers having a high degree of crystalline orientation parallel to the capillary axis. Electron diffraction and calorimetric studies indicate that a portion of the strands have an unusually high degree of order. Structural models for the strands are also proposed. Es wurde gezeigt, das sich in Hochdruck-Polyathylen in der Nahe der Schmelztemperatur und unter bestimmten Bedingungen in bezug auf Orientierung und Druck, wie sie im Instron-Extrusions-Kapillar-Rheometer vorliegen, ungewohnliche morphologische Strukturen ausbilden. Die bemerkenswert hohe optische Transparenz und die Spannungsmoduln der in diesen Faden vorliegenden morphologischen Gebilde waren Gegenstande der Untersuchungen. Einzelheiten des Kristallisationsverfahrens werden beschrieben. Die morphologischen Strukturen, die sich bei dem „Instron-Verfahren” herausbilden, wurden mit Hilfe von rontgenographischen, kalorimetrischen, mikroskopischen und mechanischen Messungen untersucht. Die transparenten Fasern setzen sich aus einer grosen Zahl von Mikrofibrillen, die einen hohen kristallinen Orientierungsgrad parallel zur Kapillarachse bestizen, zusammen. Elektronenbeugung und kalorimetrische Untersuchungen zeigen, das ein Teil der Fasern einen ungewohnlich hohen Ordnungsgrad besitzt. Es werden Strukturmodelle fur die Fasern vorgeschlagen.
Frequency/phase movement analysis by orthogonal demodulation [mixed signal SOC testing]

In mixed signal system-on-a-chip (SOC) testing, there are many opportunities to measure phase and frequency change of signals. For instance, in a PLL circuit, the lock up time is one of most typical test items. In a read/write channel device for hard disc drives, small pulse shifts for write pre-compensation are tested. Clock jitter is often evaluated in data transmission and storage devices. Since this kind of measurement needs a time stamp measurement, in general, a time interval analyzer (TIA) or a time measurement instrument is applied to do the tests. If the input frequency range of the available TIA is not high enough for the test signal, real-time digitizers having higher sampling rates than the TIA do precise time stamp measurement. The digitized data is processed with an orthogonal demodulation method, and its instantaneous phase/frequency trend is extracted. Swept frequencies, phase-shifted clocks, shifted pulses, shifted edges and clock jitter are analyzed by this method.
Milk as a vehicle for oral medications: hidden osmoles

Once critically ill, preterm infants have transitioned to enteral or oral feedings, it is common to mix oral medications with milk feedings. The osmolality of oral and intravenous drugs were tested in the 1980s and many were found to exceed the American Academy of Pediatrics (AAP) recommended limit (400 mOsm kg−1 H2O). Many new milks and medications have entered the neonatal intensive care unit (NICU) since then. The objective of this study was to measure the osmolality of common milk-medication combinations administered in the NICU. Common milk-medication mixtures were analyzed for osmolality by freezing point depression. Only Elecare (30 kcal per oz) exceeded AAP recommendations for osmolality in its unadulterated state. The addition of multivitamins alone resulted in an osmolality that exceeded 400 mOsm kg−1 H2O. The cumulative addition of other medications resulted in some osmolalities >1000 mOsm kg−1 H2O. The coadministration of medications with milk products should be evaluated as a potential contributor to gastrointestinal intolerance of feedings in preterm infants.
Food group consumption reported by the elderly during the NHANES I epidemiologic followup study

Abstract Food group consumption in the elderly (65 years of age or older) was examined using data from the food frequency questionnaire administered as part of the 1982–84 National Health and Nutrition Examination Survey's (NHANES I) Epidemiologic Followup Study (NHEFS). The number of daily servings from each food group was determined for each individual by adjusting reported frequency of consumption of food from that group (daily, weekly, monthly, yearly, and never) to a daily basis. Mean daily servings for the population of 2653 elderly were calculated for 95 NHEFS food groups combined into 32 nutritionally similar food groups, and six food groups used for current dietary guidance. Older adults reported mean daily servings greater than 1.0 for five of the 32 groups: coffee/tea, vegetable fats, non-citrus fruits, citrus fruits, and refined grains. A comparison of actual servings consumed daily with the recommended servings of six food groups indicated too few servings of dairy and grain products and adequate servings of fruits, vegetables, and protein foods. These results may be used to design nutrition education programs targeted to the elderly population.
A multithermal analysis of solar X-ray emission

The NRL SOLRAD 10 satellite carries six ionization chambers to measure solar X-radiation in the 0.5 to 60 A wavelength band. The X-ray emission spectrum in this range is determined by the derivative of the coronal emission measure (∫ Ne2dV) with respect to temperature when the thermal processes of bremsstrahlung, radiative recombination and line radiation are considered. If a simple model for this differential emission measure is used and detector responses to the calculated spectra are fitted to the SOLRAD data by a least squares method, the differential emission measure can be obtained for temperatures between 2 × 106K and 64 × 106K. Data during quiet and flaring periods are analyzed and the general behavior of the differential emission measure during flares is presented. This analysis is based on experimental measurements of the efficiencies of the SOLRAD detectors.
Approximate Decoupling of the Equations of Motion of Linear Second Order Systems

One common procedure in solving a normalized damped linear second order system with nonzero off-diagonal damping elements is to replace the normalized damping matrix by a selected diagonal matrix. The extent of approximation introduced by this method of decoupling the system is evaluated and tight upper bounds on the norm of errors are derived. Moreover, it is shown that when the normalized damping matrix is diagonally dominant, decoupling the system by neglecting the off-diagonal elements indeed minimizes the error upper bound.
Structure of 2-keto-3-deoxy-6-phosphogluconate aldolase at 2 . 8 A resolution.

Abstract The structure of 2-keto-3-deoxy-6-phosphogluconate aldolase has been extended to 2.8 A resolution from 3.5 A resolution by multiple isomorphous replacement methods using three heavy-atom derivatives and anomalous Bijvoet differences to 6 A resolution (〈 m 〉 = 0.72). The replacement phases were improved and refined by electron density modification procedures coupled with inverse transform phase angle calculations. A Kendrew model of the molecule was built, which contained all 225 residues of a recently determined amino acid sequence, whereas only 173 were accounted for at 3.5 A resolution. The missing residues were found to be part of the interior of the molecule and not simply an appendage. The molecule folds to form an eight-strand α/β-barrel structure strikingly similar to triosephosphate isomerase, the A-domain of pyruvate kinase and Taka amylase. With a knowledge of the sequence, the nature of the interfaces of the two kinds of crystallographic trimers have been examined, from which it was concluded that the choice of trimers selected in the 3.5 A resolution work was probably correct for trimers in solution. The active site region has been established from the position of the Schiff base forming Lys144 but it has not been possible to confirm it conclusively in independent derivative experiments. An apparent anomaly exists in the location of Glu56 (about 25 A from Lys144). The latter has been reported to assist in catalysis.
Structures of the native and swollen forms of cowpea chlorotic mottle virus determined by X-ray crystallography and cryo-electron microscopy.

Abstract Background: RNA–protein interactions stabilize many viruses and also the nucleoprotein cores of enveloped animal viruses (e.g. retroviruses). The nucleoprotein particles are frequently pleomorphic and generally unstable due to the lack of strong protein–protein interactions in their capsids. Principles governing their structures are unknown because crystals of such nucleoprotein particles that diffract to high resolution have not previously been produced. Cowpea chlorotic mottle virions (CCMV) are typical of particles stabilized by RNA–protein interactions and it has been found that crystals that diffract beyond 4.5 A resolution are difficult to grow. However, we report here the purification of CCMV with an exceptionally mild procedure and the growth of crystals that diffract X-rays to 3.2 A resolution. . Results The 32 A X-ray structure of native CCMV, an icosahedral ( T =3) RNA plant virus, shows novel quaternary structure interactions based on interwoven carboxy-terminal polypeptides that extend from canonical capsid β –barrel subunits. Additional particle stability is provided by intercapsomere contacts between metal ion mediated carboxyl cages and by protein interactions with regions of ordered RNA. The structure of a metal-free, swollen form of the virus was determined by cryo-electron microscopy and image reconstruction. Modeling of this structure with the X-ray coordinates of the native subunits shows that the 29 A radial expansion is due to electrostatic repulsion at the carboxyl cages and is stopped short of complete disassembly by preservation of inter-woven carboxyl termini and protein–RNA contacts. Conclusion The CCMV capsid displays quaternary structural interactions that are unique compared with previously determined RNA virus structures. The loosely coupled hexamer and pentamer morphological units readily explain their versatile reassembly properties and the pH and metal ion dependent polymorphism observed in the virions. Association of capsomeres through inter-penetrating carboxy-terminal portions of the subunit polypeptides has been previously described only for the DNA tumor viruses, SV40 and polyoma.
Application of Generalized Hopfield Networks to discrete nonlinear optimization problems

Abstract In previous work a nonlinear neural framework, the Generalized Hopfield Network, was proposed as a means of solving nonlinear optimization problems. GHNs implementing the three most important nonlinear programming algorithms: Augmented Lagrangian, Generalized reduced Gradient and Successive Quadratic Programming methods were demonstrated. In the present work, the GHN construction is extended to discrete decision problems, specifically, mixed integer nonlinear problems such as arise in process design and scheduling applications. The proposed formulation does allow a natural parallelization of the optimization calculations, distributing the computational burden among a number of digital processors linear in the problem size. Furthermore, network solution appears to be amenable to the use of simple numerical integration methods with the integration in each processor carried out asynchronously. The use of a disjunctive constraint is shown to be superior to the sigmoid filter construction. The penalty parameter of the Augmented Lagrangian implementation appears to serve as a relaxation parameter which controls the extent of the domain within which alternative local optima are sought. Two examples are given to show the potential of the method for finding global optima to MINLPs.
Oxidative stress on VWF proteolysis

In this issue of Blood , Chen and colleagues demonstrate that the rate of cleaving VWF by ADAMTS13 is significantly slowed when the residue Met1606 in the VWF A2 domain is oxidized.[1][1] The finding adds a new dimension to the complexity of regulating VWF cleavage and links the rate of VWF
Nonhomologous recombination in the human genome: deletions in the human factor VIII gene.

Abstract Four deletions in the human factor VIII gene have been characterized at the sequence level in patients with hemophilia A. Deletion JH 1 extends 57 kb from IVS 10 to IVS 18. Intron 13 and exon 14 are partially deleted in patients JH 7 and JH 37, with a loss of 3.2 and 2.4 kb of DNA, respectively. The 3′ deletion breakpoint of the JH 21 event resides in intron 3 and extends 5′ into intron 1, resulting in the loss of exons 2 and 3. Seven of the eight breakpoints sequenced (5′ and 3′ for each of the four deletions) occur in nonrepetitive sequence, while the 3′ breakpoint of the JH 1 resides in an Alu repetitive element. All of the deletions are the result of nonhomologous recombination. The 5′ and 3′ breakpoints of JH 1, JH 7, and JH 37 share 2- to 3-bp homologies at the deletion junctions. In contrast, two nucleotides have been inserted at the JH 21 deletion junction. Short sequence homologies may facilitate end-joining reactions in nonhomologous recombination events.
Relating the in-situ, ex-situ, and non-situ environments in surface electrochemistry

The relationship between ultrahigh vacuum surface science and electrochemistry is examined by comparison of so-called non-situ and ex-situ experiments performed in the vacuum environment with in-situ electrochemical experiments. Preadsorbed ClO4 on Ag(110) may be hydrated by post-adsorbed water and lifted off the surface as a hydrated complex at 170 K. This result directly illustrates the electrochemical concepts of anion desorption and nonspecific adsorption and can be explained by analogy to electrochemistry. For ex-situ studies three models exist to describe the key step of removing the electrode from the electrolyte (emersion): ideal, superequivalent, and dynamic. Ideal emersion obtains upon satisfying the criteria of (1) a 1 : 1 relationship of emersed work function with emersion potential and (2) zero charge transfer upon emersion. These criteria can be tested by Kelvin probe measurements of the work function in vacuum and re-immersion charge transient measurements in the electrochemical cell, respectively. Emersion of Pt(111) from 0.1M HClO4 + 1mM Cu2+ exhibits ideal emersion at potentials greater than 0.7VRHE and superequivalent emersion, so called because superequivalent adsorption of ClO−4 and Cl− establishes a constant work function, at emersion potentials less than 0.6VRHE. The Pb/Pt(111) system exhibits dynamic emersion behavior, characterized by a surface redox reaction between Pb0 and Pb2+ that discharges the double layer after emersion. Theoretical relationships among the non-situ, ex-situ, and in-situ methodologies are also briefly reviewed.
Cross Section as a Function of Angle for the D ( d , n ) He 3 Reaction for 10-Mev Bombarding Deuterons

By counting ${\mathrm{He}}^{3}$ particles with a proportional counter, the differential cross sections for the reaction $\mathrm{D}(d,n){\mathrm{He}}^{3}$ have been measured at laboratory angles from 16.5 degrees to 38.2 degrees (39.3 degrees to 95.0 degrees in center of mass system), for an incident deuteron energy of 10.3 Mev. In the center of mass system, the differential cross section is 4.5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}27}$ ${\mathrm{cm}}^{2}$ at 90 degrees, decreasing to a minimum of 2.2\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}27}$ ${\mathrm{cm}}^{2}$ at about 45 degrees, and rising steeply at lower angles. By determining the neutron yield with ${\mathrm{Cu}}^{63}(n,2n){\mathrm{Cu}}^{62}$ detectors, the differential cross section at zero degrees is found to be about five times that at 90 degrees (center of mass).
Modeling the cyclic loading response of sea ice

Abstract This paper describes a physically based model of the elastic and anelastic behavior of sea ice subjected to zero-mean-stress cyclic loading. It incorporates the influence of porosity and fabric. The work demonstrates that despite the complexity of the sea ice microstructure, it is possible to develop links between its physical and mechanical properties through careful experimentation and detailed physical properties measurements. As a consequence of the presence of liquid brine at temperatures of interest, the porosity of this material is temperature-dependent. The model accounts directly for the influence of temperature on the effective elastic properties (both through the lattice constants and through the total porosity), and on the dominant dislocations and grain boundary relaxation processes. It is shown via compliance measurements that the strength of the dislocation relaxation (and by inference the grown-in dislocation density) increases dramatically with the brine porosity. Naturally occurring sea ice grown in the presence of a current offers the further complexity that the c-axes of the constituent hexagonal crystals tend to align themselves with the direction of the current. Because of the overwhelming ease of slip on the basal plane relative to other slip systems, the fabric thus produced has major influence on the mechanical properties. This effect of fabric has been incorporated in the model and verified with laboratory experiments on aligned sea ice specimens. Discussion centers on the physical basis of the model and it is shown that the model predictions compare favorably with the available experimental data.
Tracking in matrix systems

Abstract This paper provides conditions, and a sense, in which the matrix of a system of linear differential or linear difference equations can be assumed to be similar to a diagonal matrix.
A novel, quantitative model for study of endothelial cell migration and sprout formation within three-dimensional collagen matrices.

Abstract Interactions between migratory endothelial cells (ECs) and surrounding extracellular matrix (ECM) are of central importance to vascular growth. Here, we present a new model of EC migration and morphogenesis within three-dimensional ECM termed “radial invasion of matrix by aggregated cells” (RIMAC). In the RIMAC model, single aggregates of defined numbers of bovine aortic ECs were embedded within small, lenticular gels of type I collagen supported by annuli of nylon mesh. Culture of the gels in nutrient media resulted in quantifiable, reproducible, radial migration of ECs into the collagen. The angiogenic proteins basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) each stimulated migration of ECs in a concentration-dependent manner. In combination, bFGF and VEGF stimulated migration synergistically. In contrast, transforming growth factor-β1 inhibited migration of ECs. Low concentrations (0.1–0.5 ng/ml) of VEGF induced ECs to form multicellular sprouts, some of which possessed lumen-like spaces. Mitomycin C, an inhibitor of cell proliferation, did not affect the migration of ECs into collagen induced by 0.5 ng/ml VEGF but moderately inhibited migration induced by 5 ng/ml VEGF. Increasing the density (concentration) of the collagen gel inhibited the migration of single ECs and increased the branching and anastomosis of multicellular sprouts. We conclude that the RIMAC model is a highly efficacious assay for the screening of potentially angiogenic and angiostatic compounds and, moreover, is advantageous for mechanistic studies of vascular morphogenesis.
Optimal anisotropic three-phase conducting composites. Plane problem

Abstract The paper establishes tight lower bound for effective conductivity tensor K∗ of two-dimensional three-phase conducting anisotropic composites and defines optimal microstructures. It is assumed that three materials are mixed with fixed volume fractions and that the conductivity of one of the materials is infinite. The bound expands the Hashin–Shtrikman and translation bounds to multiphase structures, it is derived using a combination of translation method and additional inequalities on the fields in the materials; similar technique was used by Nesi, 1995 , Cherkaev, 2009 for isotropic multiphase composites. This paper expands the bounds to the anisotropic composites with effective conductivity tensor K∗. The lower bound of conductivity (G-closure) is a piece-wise analytic function of eigenvalues of K∗, that depends only on conductivities of components and their volume fractions. Also, we find optimal microstructures that realize the bounds, developing the technique suggested earlier by Albin et al., 2007a , Cherkaev, 2009 . The optimal microstructures are laminates of some rank for all regions. The found structures match the bounds in all but one region of parameters; we discuss the reason for the gap and numerically estimate it.
Synthesis of the bis-tetrahydropyran core of amphidinol 3.

A convergent synthesis of the C31−C52 bis-tetrahydropyran core of the natural product amphidinol 3 is reported. A common intermediate was synthesized from d-tartaric acid utilizing an asymmetric glycolate alkylation/ring-closing metathesis sequence to construct the THP rings. Differential elaboration of the common intermediate allowed the synthesis of two distinct coupling partners which were joined through a modified Horner−Wadsworth−Emmons olefination to provide the bis-tetrahydropyran core.
Archaeal-eubacterial mergers in the origin of Eukarya: phylogenetic classification of life

A symbiosis-based phylogeny leads to a consistent, useful classification system for all life. "Kingdoms" and "Domains" are replaced by biological names for the most inclusive taxa: Prokarya (bacteria) and Eukarya (symbiosis-derived nucleated organisms). The earliest Eukarya, anaerobic mastigotes, hypothetically originated from permanent whole-cell fusion between members of Archaea (e.g., Thermoplasma-like organisms) and of Eubacteria (e.g., Spirochaeta-like organisms). Molecular biology, life-history, and fossil record evidence support the reunification of bacteria as Prokarya while subdividing Eukarya into uniquely defined subtaxa: Protoctista, Animalia, Fungi, and Plantae.
Preparation of [Os3(CO)11]2− and its reactions with OS3(CO)12; structures of [Et4N][HOs3(CO)11] and H2 OS4(CO

Abstract The dianion [Os3(CO)11]2− has been prepared by stoichiometric reduction of Os3(CO)12 with potassium-benzophenone ketyl. Infrared of [Et4N][HOs3(CO)11] was determined from a single crystal X-ray analysis. The anion structure consists of an Os3 triangle. One Os atom for 3558 independent reflections with I ⩾ 3σ(I). H2Os4(CO)13 was prepared by the reaction of K2[Os3(CO)11] with Os( These basal Os atoms are bridged by two single ii-H atoms. Crystal data for H2Os4(CO)13: space group P 1 , a = 9.129(4) A,
Transient crack growth under creep conditions

Abstract Transient crack growth in an elastic/power-law creeping material is investigated under antiplane shear loading and small-scale-yielding conditions. At time t = 0 the solid is suddenly loaded far from the crack by tractions that correspond to the elastic crack-tip stress distribution. At that time the crack begins to propagate at a constant velocity. The stress fields evolve in a complex manner as the crack propagates due to the competing effects of stress relaxation due to constrained creep and stress elevation due to the instantaneous elastic material response to crack growth. From detailed finite element calculations it is shown that these fields can be approximated by a simple matching of three asymptotic singular crack-tip solutions. A characteristic stress, distance and time are defined for this problem which provide a normalization that accounts for any crack velocity, loading and all material properties for a given creep exponent n . Results are presented for crack-tip stresses, strains, crack opening displacements and creep zones.
Induced anisotropy in electrically modified Polymer/Ceramic nanocomposites

Polymer/Ceramic composites with controlled spatial distribution of fillers are synthesized, and the corresponding changes in their properties are studied. Using dielectrophoretic assembly we create anisotropic composites of aligned BaTiO3 particles in silicone elastomer, and study their electrical properties as a function of ceramic volume fraction, connectivity and composite morphology. We investigate these composites for a variety of electrical properties i.e. permittivity, d.c. conduction, dielectric breakdown and energy density. The energy density of these electric-field-structured composites is found to be highly dependent on the anisotropy present in the system. This study emphasizes the important role of conductivity, permittivity, and particularly local cluster distribution in controlling high field dielectric behavior. Designed anisotropy in dielectric properties can provide new paradigms for the development of high energy density materials and gain important insights into the mechanisms that control dielectric breakdown strengths and non-linear conduction at high fields in polymer/ceramic composites.
Control schemes for tele-robotic pipe installation

Abstract Tele‐robotic operation, which allows an operator to control a mechanical tool from a safe distance, provides a technical alternative to installing buried pipes within the confines of a hazardous trench. However, the handling as well as the jointing of the many different types can't be easily replaced by remotely controllable devices. While large concrete drainage pipes are heavy, plastic pipes for sewer and water systems require careful handling to guarantee that they are properly sealed by the O‐ring gasket inside the bell. This paper will discuss the differences in control schemes that have been developed to enable the necessary operations for the two most common pipes. The paper will not only describe the designs of the many innovative components but also discuss how the many field trials with construction personnel led to successful final functionality tests for each prototype.
A determination of the sources of airborne particles collected during the regional air pollution study

Abstract Target transformation factor analysis (TTFA) has been applied to an analysis of a subset of the aerosol-composition data acquired during the Regional Air Pollution Study (RAPS) for St. Louis, Missouri. The RAPS program collected a large number of samples with 10 continuously operated dichotomous samplers from March 1975 to March 1977. The purpose of the present study was to evaluate the capability of TTFA to resolve sources of airborne particulate matter in a set of ambient-aerosol samples. In order to give each element a more equal weight in the identification of sources, a weighting scheme has been added to the target transformation rotation procedure. The weighted rotation produces a more sensitive source identification and has enhanced the resolution of sources with similar element profiles. To determine the most appropriate way to apply TTFA, two separate sets of the data were analyzed: (1) all the samples collected during July and August 1976 at a single station; and (2) all the samples collected at the ten RAPS stations during a single week. Each set of samples was further subdivided into fine- and coarse-fraction subsets which were analyzed separately. Because of the large number of missing values and values below detection limits, it was necessary to exclude a sizable fraction of the data from the analyses. Superior results were obtained from the examination of the variation in aerosol composition with time at a single location rather than the spatial variation over multiple sites during a shorter time period.
Impact of genetic testing on risk-reducing behavior in women at risk for hereditary gynecologic cancer syndromes

Background Women with hereditary breast and ovarian cancer (HBOC) have an estimated 15-65% lifetime risk of ovarian cancer; similarly, women with Lynch syndrome have a 40-60% lifetime risk of endometrial cancer and a 10-12% lifetime risk of ovarian cancer. The aim of this study was to investigate the impact of genetic testing on risk-reducing behavior for gynecologic malignancies in women being tested for HBOC and Lynch syndrome.
Topological problems in gauge theories

Abstract Various topological configurations of gauge fields are discussed from a unified point of view which emphasizes the notion of almost pure gauges. These configurations generate a nontrivial entropy S in the Feynman functional integral, thus making the free action Θ = I − g 2 S rather than the action I the relevant physical quantity. A proposal is made to use phenomenological models for H to discuss quark confinement.
Effectiveness of the slide and cross-over steps in volleyball blocking--a temporal analysis.

Abstract Three initial step techniques for moving laterally are commonly used by middle blockers in volleyball. These three methods are (1) the slide step, (2) the cross-over step, and (3) the jab cross-over step. The purpose of the current investigation was to study the relationship between the three initial step techniques and selected time variables involved in the jumping and blocking action. Four criterion measures were extracted from film footage (100 frames/sec) using cinematographic data collection techniques. Six skilled volleyball players were used as subjects (3 men and 3 women). A split-split plot 3 (step method) × 2 (response direction) × 2 (sex) factorial design, with repeated measures on method and direction, were used to analyze the criterion measures. Results of the analysis revealed a clear relationship between step method and three of the time variables studied. Specifically, the cross-over steps (and in particular the jab cross-over) were observed to be superior to the slide step in te...
New 1α,25-Dihydroxy-19-norvitamin D3 Compounds Constrained in a Single A-Ring Conformation: Synthesis of the Analogues by Ring-Closing Metathesis Route and Their Biological Evaluation

Vitamin D compounds possessing A rings prohibited from flipping to the alternative chair form (i.e., analogues 2 and 26) were synthesized. The bicyclic fragment 22 consisting of the fused cyclohexane and dihydropyran rings was constructed via the ring-closing metathesis route. Also, a homologous synthon 23 with an attached dihydropyran ring was successfully synthesized using this strategy. The carbonyl deprotection in 22 yielded cyclohexanone 5 that was subjected to Julia coupling with the anion of the phenylthiazoline sulfone 25. In the resulting isomeric 19-norvitamins 2 and 26, their A rings can exist only in the α- and β-conformation. The analogue 26 was 300 times more active in binding to the vitamin D receptor protein, 30 times more effective in causing HL-60 differentiation, and 10 times more active in transcription. These results confirm that the β-chair form of the vitamin D ring A is necessary for the binding to the receptor.
Limitations of Ampullectomy in the Treatment of Nonfamilial Ampullary Neoplasms

Background Pancreaticoduodenectomy (PD) is the standard surgical management of invasive ampullary neoplasms. A rational plan to use ampullectomy (AMP) for lesions at this location requires careful analysis of preoperative clinical information (comorbidity, lesion size, and histopathology) and intraoperative data (frozen section pathology and clinical impression) to properly select patients for this treatment.
Transverse oscillation arising from spatial soliton formation in nonlinear optical cavities

A new type of transverse instability in dispersively nonlinear optical cavities, called the optical whistle, is discussed. This instability occurs in the mean-field, soliton-forming limit when the cavity is driven with a finite width Gaussian beam, and gives rise to oscillation, period doubling, and chaos. It is also seen that bistability is strongly affected due to the oscillation within the upper transmission branch. The phenomenon is interpreted as a mode mismatch in the soliton-formation process and is believed to have broad applicability.