cssi/SciSciGPT-SciSciNet huggingface dataset:
Older Adults and Free/Open Source Software: A Diary Study of First-Time Contributors

The global population is aging rapidly, and older adults are becoming increasingly technically savvy. This paper explores ways to engage these individuals to contribute to free/open source software (FOSS) projects. We conducted a pilot diary study to explore motivations, barriers, and the contribution processes of first-time contributors in a real time, qualitative manner. In addition, we measured their self-efficacy before and after their participation. We found that what drove participants were intrinsic motivations, altruism, and internal values, which differed from previous work with older adults and with the general FOSS population. We also found that self-efficacy did not change significantly, even when participants encountered significant barriers or setbacks. The top 3 barriers were lack of communication, installation issues, and documentation issues. We found that asking for and receiving help, and avoiding difficult development environments were more likely to lead to success. To verify these results, we encourage a future large-scale diary study that involves multiple demographics. Given our pilot study, we recommend that future outreach efforts involving older adults focus on how to effectively communicate and build community amongst older contributors.
Octopamine: Normal Occurrence in Sympathetic Nerves of Rats

Octopamine has been identified in several organs of normal rats by means of a sensitive enzymatic assay. It is localized within the sympathetic nerve endings.
Atraumatic Fractures in Heart Failure

Osteoporosis and heart failure are 2 highly prevalent conditions, particularly among the elderly, both of which account for significant morbidity and mortality. In this review, we describe the epidemiology of osteoporosis and osteoporotic-related fractures in persons with heart failure. A review of the current literature regarding shared risk factors for heart failure and osteoporosis is presented, and potential common pathophysiologic mechanisms for these disorders are discussed.
Effect of Nuclear Motion on the Fine Structure of Hydrogen

The problem is re-examined from the point of view of the Hamiltonian applicable to two charged particles and accounting for effects of order $\frac{{v}^{2}}{{c}^{2}}$, where $v$ is the velocity. The work differs from that of Bechert and Meixner in that the energy of the Dirac's electron in a central field is taken as the reference point. The solution is carried out in terms of an eight-component rather than a four-component approximation to the 16-component wave function. The result is the same for practical purposes as that of Darwin for the prequantum-mechanical problem and of Bechert and Meixner for the four-component approximation. The energy formula is affected only by the original Bohr reduced mass correction to the term value and also by a term which is independent of the particular fine structure component and depends only on the principal quantum number. Bethe's electrodynamic shift is, therefore, not obscured to within terms of relative order ${\ensuremath{\alpha}}^{2}(\frac{m}{M})$ by effect of nuclear motion.
On approximation algorithms for the minimum satisfiability problem

Abstract We consider the following minimum satisfiability (MINSAT) problem: Given a CNF formula, find a truth assignment to the variables that minimizes the number of satisfied clauses. This problem was shown to be NP-complete by R. Kohli, R. Krishnamurti and P. Mirchandani (1994). They also presented an approximation algorithm whose performance guarantee is equal to the maximum number of literals in a clause. We present an approximation-preserving reduction from MINSAT to the minimum vertex cover (MINVC) problem. This reduction, in conjunction with known heuristics for the MINVC problem, yields a heuristic with a performance guarantee of 2 for MINSAT. Further, we show that if there is an approximation algorithm with a performance guarantee ϱ for MINSAT, then there is an approximation algorithm with the same performance guarantee ϱ for the minimum vertex cover problem. This result points out the difficulty of devising an approximation algorithm with a performance guarantee better than 2 for MINSAT. We also observe that MINSAT remains NP-complete even when restricted to planar instances.
Novel acylation of poxvirus A-type inclusion proteins.

Abstract Myristylation is one of several post-translational modifications that occur on vaccinia virus (VV) proteins. Previously, time course labeling of VV-infected cells with myristic acid had indicated that five late proteins (17, 25, 36, 38 and 92 kDa) are myristylated. Four of these proteins were mapped to the E7R, L1R, AI6L and G9R open-reading frames, respectively, because of the predicted presence of the N -myristyltransferase recognition sequence (M-G-X-X-X-S/T/A) at their amino termini. In contrast, computer analyses of large (80–100 kDa) VV open reading frames did not reveal any predicted species with this N-terminal motif. By immunoprecipitation with monospecific sera and transient expression of cloned gene products, the myristylated 92-kDa protein has been demonstrated to be the A-type inclusion protein encoded by the Western Reserve (WR) strain of VV. Labeling of cowpox virus (CPV) infected cells with myristic acid indicated that the 160-kDa A-type inclusion protein appears to be myristylated as well. Both the VV 92-kDa and the CPV 160-kDa A-type inclusion proteins labeled with myristic acid were stable to hydroxylamine treatment, suggesting an amide linkage between the fatty acid and the acceptor protein. HPLC analysis confirmed that the 92-kDa protein was in fact myristylated. This data suggests that poxvirus ATI proteins may be subject to a novel type of internal myristylation modification, and the roles such modifications may play in the replication cycles of these viruses is discussed.
The Ambiguity of Reform in the New Deal

By the end of the 1940s, it was clear that New Deal liberalism had changed. Cabell Phillips, a journalist, wrote that the Fair Deal had abandoned a liberalism preoccupied with poverty and inequality and “focused on the creation and equitable distribution of abundance, which now loomed as an attainable reality.” Economic growth had become the talisman of liberal policies, both foreign and domestic. Fair Deal conservation policy, for example, abandoned the New Deal's emphasis on resource planning and redistribution of economic power and reshaped federal land, water, and grazing programs into tools of economic expansion. Similarly, postwar America put production and efficiency at the center of international debates over foreign exchange and foreign aid to war-torn Europe. The place of economic growth in postwar liberalism is often understood to reflect the conservative turn in American politics that followed the war with Harry Truman's presidency and the cold war's onset.
The effects of argument preparation and timing of first offer on negotiators' cognitions and performance

We investigate how argument preparation (self-only, self/counter) and the timing of the first offer (immediate, delayed) combine to affect negotiation performance. Subjects participated in a dyadic negotiation concerning the out-of-court settlement of a lawsuit. Subjects prepared by generating a list of arguments in support of their case (self-only), or by generating a list of arguments in support of their caseaccompanied by a list of counterarguments that they might expect from their opponent (self/counter). In the Immediate Offer condition, subjects began the negotiation with an exchange of written settlement offers. In the Delayed Offer condition, subjects began the negotiation with a discussion of the qualitative negotiation issues. It was proposed that negotiators who prepared both their own and counterarguments would be more flexible and that this effect would be increased by delaying the first offer. The results indicate that the effects of these variables are more complex than originally proposed, and reveal significant interactions with the negotiator's role in the conflict.
Computer Work Stations: Preferred Posture and Line of Sight

Ergonomic design of the computer work station can not rely on assuming an upright body position, but must accommodate various and varying postures.
Fiber Arrangement and Micro‐Structure of Bovine Longissimus Dorsi Muscle

SUMMARY An experiment was conducted to establish the fiber arrangement and micro-structure at three sites in the longissimus dorsi of horizontally placed and vertically suspended bovine carcass sides. Fiber angles, from transverse processes, increased markedly from anterior to posterior positions. Conversely, the fiber angles, from the spinous processes, decreased from anterior to posterior positions. In comparison with horizontal placement, vertical suspension released some of the tension on the longissimus dorsi and allowed rearrangement of its internal construction. This rearrange. ment was noted by larger angles, from both the transverse and spinous processes, and shorter sarcomeres in the vertically suspended than in the horizontally placed sides. Differences were also observed in muscle shape and marbling coarseness.
A Device to Measure Heat Flow Through the Skin in People with Diabetes

Abstract Introduction: As people age, and especially for older people with diabetes, there is increased susceptibility to burns. However, this is not true for all older people or all people with diabetes. The factors that predict burn susceptibility in specific members of the population with diabetes have not been elucidated. To understand the heat transfer properties of the skin in different parts of the body and how it is altered by skin blood flow, age, and glycemic control, a new device was developed. Methods: The device was a Plexiglas® (Arkema, Colombes, France) capsule (thermode) that has a footprint on the skin of 20 cm2, with the side contacting the skin made of thin brass. The thermode was machined to allow the free flow of water through the interior with the exception of a small hole for a laser Doppler flow meter to assess blood flow under the capsule. Flow directors kept the water flow even on the under surface of the capsule and minimized turbulent flow until high water flow rates are forced...
Root amputation and bone grafting of failed apicoectomy of mesiobuccal root of maxillary first molar

Root amputation is an option available to extend the function of a molar tooth when there is a persistent endodontic failure. This case report of a 52-year-old male provides an overview of the feasibility of mesiobuccal root amputation and bone grafting with calcium sulfate of maxillary right first molar after failed non-surgical and surgical endodontics due to root fracture. A 2 year follow-up showed successful clinical and radiographic results. In specific situations, root amputation is a viable treatment to retain a functional portion of the tooth.
Determination of human apolipoprotein e by electroimmunoassay

1. Apolipoprotein E ("arginine-rich" polypeptide) was isolated from delipidized human very low density lipoproteins by agarose column chromatography in the presence of 6 M guanidine-hydrochloride. 2. An electroimmunoassay ("rocket" electrophoresis) is described for quantitative determination of human serum apolipoprotein E. Purified apolipoprotein E was used for the preparation of monospecific antisera and standardization of assay. This sensitive, specific, rapid (time required for the completion of the assay is 5 h) and precise (the within- and between-assay coefficients of variation are 5 and 8%, respectively) assay is applicable to measurement of apolipoprotein E in whole serum and density classes. The results correlated well with those obtained by radial immunodiffusion (r = 0.85). 3. Serum apolipoprotein E levels of normal subjects and hyperlipoproteinemic phenotypes IIa, IIb and IV were the same (10 to 16 mg/100 ml). In contrast, patients with type III and V hyperlipoproteinemias had markedly elevated serum apolipoprotein E levels )27 and 25 mg/100 ml, respectively). The apolipoprotein E in serum of normolipidemic subjects was equally distributed among three major lipoprotein density classes: d less than 1.030 g/ml (27%), d 1.030-1.063 g/ml (36%)and d 1.063-1.21 g/ml (37%).
Squatter Sam and Professionalism

In this issue, the On Being a Doctor story of Squatter Sam is well worth reading and sharing. It is a physician's story—a story about the kind of patient we all remember well. With a few words, thi...
NL ∩ IR: Natural language for information retrieval

Neither natural language processing nor information retrieval is any longer a young field, but the two areas have yet to achieve a graceful interaction. Mainly, the reason for this incompatibility is that information retrieval technology depends upon relatively simple but robust methods, while natural language processing involves complex knowledge-based systems that have never approached robustness. We provide an analysis of areas in which natural language and information retrieval come together, and describe a system that joins the two fields by combining technology, choice of application area, and knowledge acquisition techniques. © 1989 Wiley Periodicals, Inc.
Effects of Ceramic Parameters on Microwave Properties of Nickel Ferrite

A simple apparatus is described for measuring the magnetic loss as a function of magnetic field for ferrites at a frequency of 10,000 mc. The width of the ferromagnetic resonance curve is as important a factor in designing microwave devices as is the resistivity of these materials. The method of preparing ferrites and the physical properties of polycrystalline nickel ferrites as affected by preparation and firing techniques are discussed. It is shown that pores in the ferrite body substantially increase the width of the ferromagnetic resonance curve. The direct-current resistivity can be made to vary from 10 ohm-cm. to 109 ohm-cm. by changing the firing temperatures. The variation in the relative permeability with the bulk density of the body is discussed with reference to domain rotation and domain wall movement.
Moving FDIC insurance to an asset-based assessment system: Evidence from the special assessment of 2009

Abstract In the second quarter of 2009, the FDIC imposed a special assessment on insured banks to replenish the deposit insurance fund. While the traditional assessment base for regular deposit insurance premiums was all insured deposits, the special assessment was applied to a bank's total assets minus Tier 1 capital (total liabilities), with the maximum ‘capped’ at 10 basis points of insured deposits. We find that the cap yielded the greatest savings for banks with assets above $10 billion and that the FDIC would have raised a substantially greater amount of funds using holding company adjusted assets or could have applied a lower assessment rate to collect the same amount of proceeds.
Hierarchically Etched Silicon Lotus Effect Surface Structures for Reduced Light Reflection

Superhydrophobic self-cleaning lotus effect surfaces are of interest for a variety of applications such as self-cleaning, water repellency and anticorrosion properties. Numerous approaches to generate superhydrophobic surfaces have been proposed. In these studies, high contact angles and reduced contact angle hysteresis were intensively investigated. In our study, we invoked a surface etching technique for the preparation of multi-functional (self-cleaning, non-reflecting, water repellent) surface micro/nano structures for potential photovoltaic applications. A facile way of forming superhydrophobic surfaces is reported that uses Au assisted HF/H2O2 etching of silicon wafers. The Au layer was deposited onto a silicon wafer via e-beam evaporation. By controlling the evaporation and etching times, the surface roughness can be manipulated and superhydrophobic surfaces with different optical properties can be generated. Contact angles were measured with a CCD camera equipped goniometer; these values determined the water repellency. Light reflection on the as prepared black surfaces was measured to assess the efficiency for low cost solar cell applications. It is expected that by controlled manipulation of surface structures via the etching process, multifunctional silicon surfaces can be achieved and cost-effective photovoltaics may be possible[1].
Axonal projection patterns of neurons in the secondary gustatory nucleus of channel catfish

The secondary gustatory nucleus of teleost fishes receives ascending fibers from the primary gustatory center in the medulla and sends efferent fibers to several nuclei in the inferior lobe of the diencephalon. Similar to the corresponding parabrachial nucleus in birds and mammals, the secondary gustatory nucleus of catfish consists of several cytoarchitectonically distinct subnuclei which receive input from different portions of the primary gustatory nuclei. However, it is unclear how the subnuclear organization relates to the processing of gustatory information in the hindbrain and the subsequent transmission of that information to the forebrain. To determine whether cells within different subnuclei of the secondary gustatory nucleus of channel catfish project to different diencephalic targets, single cells were intracellularly labeled with biocytin. Three subnuclei have been identified in the secondary gustatory nucleus: a medial subnucleus spanning most of the rostrocaudal extent of the nucleus, a central subnucleus and a dorsal subnucleus, the latter two located in the rostrolateral portion of the complex. Cells throughout the secondary gustatory nucleus typically possessed similar collateral projections to several nuclei in the inferior lobe, although four of the six cells filled in the medial subnucleus projected only to nucleus centralis. The only apparent subnucleus-specific projection pattern involved cells at the rostral edge of the secondary gustatory nucleus and in the secondary visceral nucleus. Axons of these cells terminated only in restricted portions of nucleus lobobulbaris. These results suggest that efferents from different subnuclei of the secondary gustatory nucleus of catfish, like those of the parabrachial nucleus of birds and mammals, do not possess simple, topographical projections to target nuclei in the diencephalon. © 1996 Wiley-Liss, Inc.
Age- and Gene-Dosage–Dependent Cre-Induced Abnormalities in the Retinal Pigment Epithelium

To conditionally inactivate genes in the retinal pigment epithelium (RPE) transgenic mouse strains have been developed, in which Cre recombinase (Cre) expression is driven by an RPE-specific gene promoter. The RPE is a quiescent epithelium, and continuous expression of Cre could affect its function. Here, we tested the hypothesis that continuous postnatal Cre expression in the RPE may lead to cellular abnormalities, which may depend on both age and Cre gene dosage. We therefore examined the eyes of homozygous and heterozygous VMD2-Cre mice at various ages. In VMD2-Cre heterozygous mice variable progressive age-dependent RPE abnormalities were noticed, including attenuation of phalloidin and cytoplasmic active β-catenin staining, reduced cell size, and loss of the typical honeycomb pattern of RPE morphology in those RPE cells that stained for Cre. These morphological RPE abnormalities were not noticed in Cre-negative RPE cells in VMD2-Cre or age-matched control mice. In addition, an abnormal number and morphology of cell nuclei were noticed in a subset of Cre-expressing RPE cells in aged heterozygous VMD2-Cre mice, whereas more severe nuclear abnormalities were observed already in young homozygous VMD2-Cre mice. Thus, continuous postnatal expression of Cre causes abnormalities in the RPE in an age- and Cre gene dosage-dependent manner, which needs to be considered in the interpretation of gene targeting studies in the RPE.
Partial Synthesis of Krukovines A and B, Triterpene Ketones Isolated from the Brazilian Medicinal Plant Maytenus krukovii

Krukovines A (1) and B (2), triterpene ketones isolated from the Brazilian medicinal plant “chuchuhuasi” (Maytenus krukovii), were synthesized in eight steps from the commercially available oleanol...
'Herringbone' defect formation in planar-flow melt spinning

Abstract A short-wavelength, periodic feature (≈1 mm) similar in appearance to a herringbone pattern appeared on ribbon produced at high rates (≈10 m/s) by the planar-flow process. These marks corresponded to a high-frequency (≈10 kHz) disturbance to the process stream. Observations of herringbone formation came from ribbon profilometry, customized nozzle tests and high-speed meniscus imaging. These observations were compared against observations of the ‘crosswave’ feature formation which were subject to prior study. It is demonstrated here that herringbone marks, in contrast to the crosswave marks, were mainly influenced by the substrate motion of translation. Herringbone formation is also reported to have correlated with the pinning of the liquid puddle at the nozzle edge.
Disruption of HDAC/CoREST/REST repressor by dnREST reduces genome silencing and increases virulence of herpes simplex virus

In nonneuronal cells, herpes simplex virus 1 overcomes host defenses, replicates, and ultimately kills the infected cell. Among the host defenses suppressed by the virus is a repressor complex whose key components are histone deacetylase (HDAC) 1 or 2, RE-1 silencing transcription factor (REST), corepressor of REST (CoREST), and lysine-specific demethylase (LSD) 1. In neurons innervating cells at the portal of entry into the body, the virus establishes a “latent” infection in which viral DNA is silenced with the exception of a family of genes. The question posed here is whether the virus hijacks this repressor complex to silence itself in neurons during the latent state. To test this hypothesis, we inserted into the wild-type virus genome a wild-type REST [recombinant (R) 111], a dominant-negative REST (dnREST) lacking the N- and C-terminal repressor domains (R112), or an insertion control consisting of tandem repeats of stop codons (R113). The recombinant virus R112 carrying the dnREST replicated better and was more virulent than the wild-type parent or the other recombinant viruses when administered by the corneal or i.p. routes. Moreover, in contrast to other recombinants, corneal route inoculation by R112 recombinant virus resulted in higher DNA copy numbers, higher levels of infectious virus in eye, trigeminal ganglion, or brain, and virtually complete destruction of trigeminal ganglia in mice that may ultimately succumb to infection. These results support an earlier conclusion that the HDAC/CoREST/REST/LSD1 repressor complex is a significant component of the host innate immunity and are consistent with the hypothesis that HSV-1 hijacks the repressor to silence itself during latent infection.
Impacts of amorphous and crystalline cobalt ferrite layers on the giant magneto-impedance response of a soft ferromagnetic amorphous ribbon

A systematic study of the effect of depositing CoFe2O4 (CFO) films of various thicknesses (d = 0–600 nm) on the giant magneto-impedance (GMI) response of a soft ferromagnetic amorphous ribbon Co65Fe4Ni2Si15B14 has been performed. The CFO films were grown on the amorphous ribbons by the pulsed laser deposition technique. X-ray diffraction and transmission electron microscopy revealed a structural variation of the CFO film from amorphous to polycrystalline as the thickness of the CFO film exceeded a critical value of 300 nm. Atomic force microscopy evidenced the increase in surface roughness of the CFO film as the thickness of the CFO film was increased. These changes in the crystallinity and morphology of the CFO film were found to have a distinct impact on the GMI response of the ribbon. Relative to the bare ribbon, coating of amorphous CFO films significantly enhanced the GMI response of the ribbon, while polycrystalline CFO films decreased it considerably. The maximum GMI response was achieved near the onset of the structural transition of the CFO film. These findings are of practical importance in developing high-sensitivity magnetic sensors.
ΔF508 CFTR Expressed In Xenopus Oocytes Exhibits Unique Thermal Sensitivity

The deletion of a phenylalanine at position 508 is the most common, disease-related mutation in the CFTR protein. ΔF508 CFTR channels are assembled in mammalian cells, but exhibit two deficiencies thought to underlie the disease phenotype: impaired trafficking and defective gating. The CFTR trafficking defect is partially mitigated at low temperature so that Xenopus oocytes are ideal for studying the physical properties of ΔF508 channels under physiological conditions. In order to investigate possible effects of the Phe deletion on the intrinsic stability of CFTR channel function in the plasma membrane, we monitored channel activity at room temperature (∼23°C) and during a brief (10-12 minute) period of elevated temperature (28°C to 37°C). In oocytes expressing wild type CFTR, a temperature challenge resulted in a reversible increase in the conductance; a result of a simultaneous increase in single-channel conductance and open probability. Both parameters, however, returned to baseline values when the temperature was returned to 23°C. In marked contrast, conductance due to ΔF508 CFTR channels exhibited a transient increase within a minute after the temperature challenge, followed by a quasi-exponential decline of about 80-90% of the initial conductance (t1/2 = 4 minutes at 37°C). The temperature induced decrease in ΔF508 CFTR conductance was not reversed by returning the temperature to 23°C. The second-site reverent construct, R553M/ ΔF508 CFTR, previously shown to rescue CFTR function in mammalian cells (Teem et al. 1993. Cell. 73:335-346), exhibited a thermal response that was indistinguishable from wild type. Preliminary data suggests that this “thermal instability” that is readily detectable when ΔF508 CFTR is expressed in Xenopus oocytes, reflects an intrinsic structural defect in the channel protein that results in a temperature-sensitive alteration in gating and could potentially trigger the retrieval of surface protein documented in mammalian cells.
Why are some international agreements informal

Informal agreements are the most common form of international cooperation and the least studied. Ranging from simple oral deals to detailed executive agreements, they permit states to conclude profitable bargains without the formality of treaties. They differ from treaties in more than just a procedural sense. Treaties are designed, by long-standing convention, to raise the credibility of promises by staking national reputation on their adherence. Informal agreements have a more ambiguous status and are useful for precisely that reason. They are chosen to avoid formal and visible national pledges, to avoid the political obstacles of ratification, to reach agreements quickly and quietly, and to provide flexibility for subsequent modification or even renunciation. They differ from formal agreements not because their substance is less important (the Cuban missile crisis was solved by informal agreement) but because the underlying promises are less visible and more equivocal. The prevalence of such informal devices thus reveals not only the possibilities of international cooperation but also the practical obstacles and the institutional limits to endogenous enforcement.
The Vocabularies of Higher Education: Addressing the Problems They Create

While fresh hires had the right technical know-how for the job, said most employers in the survey, they grumbled that colleges weren't accurately preparing students in written and oral communicatio...
Efficient SIMD Code Generation for Runtime Alignment and Length Conversion

When generating codes for today's multimedia extensions, one of the major challenges is to deal with memory alignment issues. While hand programming still yields best performing SIMD codes, it is both time consuming and error prone. Compiler technology has greatly improved, including techniques that simdize loops with misaligned accesses by automatically rearranging mis-aligned memory streams in registers. Current techniques are applicable to runtime alignments, but they aggressively reduce the alignment overhead only when all alignments are known at compile time. This paper presents two major enhancements to the state of the art, improving both performance and coverage. First, we propose a novel technique to simdize loops with runtime alignment nearly as efficiently as those with compile-time misalignment. Runtime alignment is pervasive in real applications because it is either part of the algorithms, or it is an artifact of the compiler's inability to extract accurate alignment information from complex applications. Second, we incorporate length conversion operations, e.g., conversions between data of different sizes, into the alignment handling framework. Length conversions are pervasive in multimedia applications where mixed integer types are often used. Supporting length conversion can greatly improve the coverage of simdizable loops. Experimental results indicate that our runtime alignment technique achieves a 19% to 32% speedup increase over prior art for a benchmark stressing the impact of misaligned data. We also demonstrate speedup factors of up to 8.11 for real benchmarks over sequential execution.
Net migration, unemployment, and the business cycle.

An empirical test of the effects of exogenous shocks upon a regions population size is conducted in the framework of an equilibrium locational model. The model emphasizes the separation of endogenous from exogenous factors a point omitted in most empirical studies of aggregate migration. Exogenous changes are manifested in the local relative cost of living and the local relative unemployment rate. Hypotheses are tested using a national sample of youth in addition to census data [for the United States]. Surprisingly a simple measure of the size of shock to a regional economy has the greatest explanatory power compared to more sophisticated measures based on prior business cycles. (EXCERPT)
Deleted Residuals, the QR-Factored Newton Iteration, and Other Methods for Formally Overdetermined Determinate Discretizations of Nonlinear Eigenproblems for Solitary, Cnoidal, and Shock Waves

Abstract Solitary waves, cnoidal waves, and shock waves can be computed by solving a nonlinear eigenvalue problem, which in discretized form is a system of nonlinear algebraic equations. Unfortunately, many such systems are singular because the solution is not unique until one or more additional constraints are imposed. For example, if the waves are translationally invariant and u(X) is a solution, then so also is u(X+Φ) for arbitrary Φ. To obtain a unique solution, one must impose an additional condition to reduce the one-parameter family of solutions by constraining Φ. We describe five methods for coping with such singular systems: (i) reformulation of the problem, (ii) deleting residuals, (iii) Keller's bordered matrix scheme, (iv) QR-factored, overdetermined Newton iteration, and (v) pseudoinverse-Newton iteration. We illustrate these ideas using the cnoidal waves of the Korteweg–de Vries equation, the traveling shocks of the Korteweg–de Vries-Burgers equation, and the weakly nonlocal solitary waves of the nonlinear equatorial beta-plane equations. Finite difference, Fourier and rational Chebyshev pseudospectral methods, and spectrally upgraded finite differences are applied. Reformulation and deleting residuals are the cheapest strategies, but the QR-factored Newton iteration is needed for the shock waves, which lack the symmetry of the other two wave species.
Nonlinear modeling of the vehicle/structure interaction on a skewed highway bridge using an iterative uncoupled approach

Vehicle/structure interaction is extremely important in determining the structural performance of highway bridges. However, an accurate prediction of the generated vibrations and forces requires a high-fidelity nonlinear 3D model which is sufficiently representative of the actual vehicle and bridge structure. In spite of all the computational advancements, there are still many technical difficulties to obtain a converging solution from a coupled highly nonlinear and highly damped vehicle/structure models. This paper presents an iterative uncoupled approach to obtain an accurate estimation of the vehicle/structure interaction. The multi-axle vehicle is simulated using a nonlinear 3D multibody dynamics model. The bridge model also contains several nonlinear components to accurately model the bridge behavior. The vehicle/bridge interaction results are obtained through an iterative solution by exchanging the outputs of two uncoupled nonlinear models. A convergence criterion is selected to obtain a reliable solution after several of these iterations. Finally, a reduced-order model of the bridge is developed using a state-space model. The linear reduced-order model of the bridge is coupled with the nonlinear vehicle model to improve the solution time of the analysis. The results are in a very good agreement with the iterative uncoupled approach. Â© 2012 SPIE.
Vertex-distinguishing proper edge-colorings

An edge-coloring is called vertex-distinguishing if every two distinct vertices are incident to different sets of colored edges. The minimum number of colors required for a vertex-distinguishing proper edge-coloring of a simple graph G is denoted by . A simple count shows that where ni denotes the number of vertices of degree i in G. We prove that where C is a constant depending only on Δ. Some results for special classes of graphs, notably trees, are also presented. © 1997 John Wiley & Sons, Inc. J Graph Theory 26: 73–82, 1997
Critical layer thickness in compositionally-graded semiconductor layers with non-zero interfacial mismatch

The critical layer thicknesses for the glide of misfit dislocations have been determined for compositionally-graded semiconductor layers with non-zero interfacial mismatch. Two cases have been considered: the case for which the interfacial mismatch (or 'pre overshoot') has the same sign as the grading coefficient (referred to as 'jump graded') and the case in which the signs are opposite (called 'retro graded'). A force-balance approach was used, and it was assumed that threading dislocations would glide to create misfit dislocations if the glide force exceeded the line tension. We find that for a jump-graded structure with a particular value of interfacial mismatch, the critical layer thickness decreases monotonically with the absolute value of the grading coefficient. Retro-graded structures exhibit more complicated behavior; for a particular combination of interfacial mismatch and grading coefficient, there may be three different thicknesses for which the line tension and glide force of the dislocation are equal, denoted hc1, hc2 and hc3. Lattice relaxation by glide of grown-in dislocations is favorable for thicknesses in the range hc1 hc3. This complicated behavior must be considered when modeling the strain relaxation and dislocation dynamics in retro-graded buffer structures.
Epigenetic turn ons and turn offs: chromatin reorganization and brain differentiation.

Early environmental and hormonal signals induce subtle epigenetic modifications to chromatin that function to turn on and off gene expression and create lasting differences within the brain.
Controlled and Reversible Aggregation of Biotinylated Gold Nanoparticles with Streptavidin

Biotinylated gold nanoparticles were prepared by using a two-step surface modification procedure. First, a carboxyl-terminated alkanethiol was chemisorbed onto the surface of gold nanoparticles in the presence of a stabilizing agent. Subsequently, the carboxyl groups were reacted with (+)-biotinyl-3,6,9,-trioxaundecanediamine and 2-(2-aminoethoxy)ethanol. This procedure resulted in stable, ligand-modified gold nanoparticles. Upon interaction with streptavidin, the biotinylated gold nanoparticles aggregated by means of specific biomolecular recognition. Their aggregation was studied by optical absorption spectroscopy. Controlled aggregation of biotinylated gold nanoparticles resulted in a shift in the surface plasmon resonance peak and broadening of the absorption spectrum of the nanoparticles. The spectral changes were used to assess the extent of aggregation. Aggregation was found to be dependent on the concentrations of streptavidin, biotinylated gold nanoparticles, and the surface mole fraction of biot...
Possible involvement of opiate receptors in the pharmacological profiles of antidepressant compounds

Tricyclic antidepressants and selected hydroxylated metabolites were found to inhibit [3H]naltrexone binding in whole rat brain. The drug concentrations required to inhibit binding appeared to be within pharmacological relevant brain concentrations. Carbamazepine and several monoamine oxidase inhibitors (with the exception of clorgyline) were inactive in this regard. The relative potency of the tricyclic antidepressants with regard to inhibitions of opiate binding in brain did not correlate with their clinical efficiency as antidepressants, suggesting that these compounds probably do not exert their antidepressant effects through opioid peptidergic systems in brain. In addition, we found that imipramine (30 mg/kg) had antinociceptive properties, as assessed by the hot plate procedure, which were partially, but not significantly, reversed by naloxone (2 mg/kg). The possibility that opioid receptors may be involved in the analgesic properties of the tricyclic antidepressants has been discussed.
Applications of the integrated-blanket-coil concept to the compact reversed-field pinch reactor

Compact reactors, by their nature, are high-power-density devices. They place a premium on space usage within the system volume, and access to the fusion power core components is limited. The integrated-blanket-coil (IBC) concept relaxes some of these requirements by combining the functions of the breeding blanket with those of the magnet systems. In this paper, the IBC potential is analyzed for the compact reversed-field pinch reactor (CRFPR) coil sets: (a) the toroidal field (TF) system; (b) the polidal field (PF) system; (c) the ohmic heating (OH) subsystem of the PF system; and (d) the divertor coils in the impurity control system. Use is made of the Los Alamos National Laboratory (LANL) RFP systems code with suitable modifications, to estimate ohmic losses, coil masses, and economic (cost of electricity) impact of the different configurations. Preliminary evaluations indicate that a symmetric toroidal divertor would be suitable for the CRFPR. This presents a special attraction for use of IBC divertor coils. Since the minority field (TF) is < 1 T at the plasma edge, the required nulling current is modest. In addition, IBC coils can be placed closer to the plasma, allowing a trade-off between the higher resistive losses and reduced current requirements.more » Perhaps most importantly, use of IBC divertor coils would improve the tritium breeding ratio, which is somewhat marginal with copper divertor coils.« less
Studies of children’s probability learning behavior: VII. Effect of reward expectancy

Thirty-six third-grade children participated in a probability learning task under one of three presumed motivational levels. Rewarded children received toys for participating in the experiment. Children in a reward-expectancy group did not receive any toys in the experiment, but they did observe the rewarded children return to the classroom with toys. A control group did not receive or expect reward. The results indicated that the expectancy children were disappointed and withdrawn when they learned that they would not receive any toys. Performance differences were found in the children’s response strategies but not in the overall probability learning behavior of the three groups.
Translinear root-difference-of-squares circuit

A simple translinear circuit is proposed to provide analogue root-difference-of-squares operation. Fully compatible with s.i.c. technology, the circuit can be used for r.m.s. subtraction, magnitude sine-to-cosine conversion and frequency doubling. Experimental results are presented to support the theory.
The Emergence of the Personal Vote

Some scholars have argued that the increase in incumbency advantage and, thus, the advent of the personal vote were produced by the emergence of representatives during the 1950s who enhanced their electoral prospects by exploiting their ability to provide constituents with a wide array of services, and then parlaying their "help" into votes (Alford and Brady 1993; Cain, Ferejohn, and Fiorina 1987; Fiorina 1977a, 1977b). This study utilizes some uniquely placed, yet previously neglected, data about the views of candidates for Congress in the time period in question. We use data from the Miller-Stokes 1958 representation study to see whether representatives with different styles of representation can be identified in this transition period. Our analysis supports the theory that a new type of representative emerged in the late 1950s and that this new style resulted, at least in 1958, in larger vote margins.
Prenatal Birth Planning for Families of the Imperiled Newborn

Guidelines have not been established to address the needs of parents with imperiled newborns due to the infrequency of this obstetric situation. In this article we offer an approach to prenatal care planning for imperiled newborns and their families. Use of an interdisciplinary team and family involvement are the foci of the care planning process, which result in a perinatal birth plan that reflects parental values and ethical guidelines.
An authentication protocol in Web-computing

A web-computing system (WCS) allows a host with limited resources to perform CPU intensive tasks by outsourcing the computations to external clients. But not every client is trusted, and redundancy in task assignment and auditing of results are needed to ensure the integrity of the results. This raises the question as to the efficiency and reliability of the system as measured against a given unit of the host's auditing time or cost. In this paper we propose a WCS with low overhead and has favorable error rate compared to a majority-voting scheme with similar efficiency. We can reduce the error rate by re-authenticating the results without having to resubmit any jobs, and we have an auditing strategy that in many cases is probabilistically better than random sampling.
Conflict resolution for air traffic management: a study in multiagent hybrid systems

Air traffic management (ATM) of the future allows for the possibility of free flight, in which aircraft choose their own optimal routes, altitudes, and velocities. The safe resolution of trajectory conflicts between aircraft is necessary to the success of such a distributed control system. In this paper, we present a method to synthesize provably safe conflict resolution manoeuvres. The method models the aircraft and the manoeuvre as a hybrid control system and calculates the maximal set of safe initial conditions for each aircraft so that separation is assured in the presence of uncertainties in the actions of the other aircraft. Examples of manoeuvres using both speed and heading changes are worked out in detail.
Intracisternal A Particle Formation and Inhibition in Preimplantation Mouse Embryos

Intracisternal A particle (IAP) formation and inhibition in preimplantation mouse embryos were studied at different stages. The embryos were collected by flushing the oviducts. LAP particles were observed in large numbers within the endoplasmic reticulum at approximately the 4-cell stage. 2-cell embryos exhibited many regions of budding particles at numerous cytoplasmic locations within both cells. The cytoplasmic regions were characterized by fibrous material and contained a few complete intracisternal A particles a small amount of crystalloid material and a few 20 nm diameter granules. 80-100% 24-hour zygote cultures reached the 2-cell stage and showed regions interpreted as even earlier stages in IAP formation with no budding in most of these regions. Only 2 of 24 zygotes cultured in actinomucin D reached the 2-cell stage. However when cultured in alpha-amantin morphologically normal presumptive IAP regions were observed in the 2-cell embryo. These results support a cytoplasmic origin for the immature stage of the virus but do not exclude possible nuclear involvement.
Emergent and Nonemergent Nonbowel Torsion: Spectrum of Imaging and Clinical Findings

Timely diagnosis and characterization of torsion, a condition that may involve many anatomic structures besides the bowel, is critical for triaging patients either to immediate surgery for organ salvage or to conservative management and depends on interpretation of findings at US and CT as well as clinical signs and symptoms.
Development of large size high-purity germanium crystal growth

Abstract Growing large diameter (∼15 cm) dislocation-free crystals for the GEODM experiment at DUSEL is a challenging task. A crystal of such high purity and large size has never been grown before and the process will require much research and development. In pursuing this goal, we are growing high-purity germanium crystals by the Czochralski method in our laboratory at USD in order to understand the details of the growing process, especially for large diameter crystals. Using a radio frequency (RF) heating method, germanium crystals with two different orientations (along 〈100〉 and 〈111〉) have been grown. The growth characteristics of 〈100〉 crystals have been investigated to understand the impact of the thermal field on the size of the grown crystals. In order to establish the optimal thermal field for growing large high-purity germanium crystals, three different radial thermal fields have been studied. Furthermore, the dislocation density in the grown crystals was measured using an optical microscope and was determined to be about 1×103–4×103/cm2, which falls in the required range for a high-purity germanium detector. X-ray diffraction tests on the surfaces of (100) indicate the grown crystals are of high quality.
Increasing phonological complexity reveals heightened instability in inter-articulatory coordination in adults who stutter

The potential role of phonological complexity in destabilizing the speech motor systems of adults who stutter was explored by assessing the performance of 17 adults who stutter and 17 matched control participants on a nonword repetition task. The nonwords varied in length and phonological complexity. Behavioral results revealed no differences between the stuttering and normally fluent groups on accuracy of nonword repetition. In contrast, dramatic differences between groups were observed in the kinematic data. Indices of the consistency of inter-articulator coordination revealed that adults who stutter were much less consistent in their coordinative patterns over repeated productions. With increasing length and complexity of the nonwords, between-group differences in coordinative consistency were more pronounced. Coordination consistency measures revealed that adults who stutter (but not normally fluent adults) showed within-session practice effects; their coordinative consistency improved in five later compared to five earlier productions. Adults who stutter produced the nonwords at a slower rate, but both groups showed increased rates of production on the later trials, indicating a practice effect for duration for both groups. We conclude that, though the adults who stutter performed behaviorally with the same accuracy as normally fluent adults, the nonword repetition task reveals remarkable differences in the speech motor dynamics underlying fluent speech production in adults who stutter compared to their normally fluent peers. These results support a multifactorial, dynamic model of stuttering in which linguistic complexity and utterance length are factors that contribute to the probability of breakdown of the speech motor system.
MPX-PC: an operating system project for the PC

This paper describes a student operating system project, MPX-PC, that can be implemented on an IBM PC-compatible computer. Seven modules make up the project, with the seventh module being the completion of a “stand-alone” student multiprogramming operating system. The project is implemented in Turbo C.