cssi/SciSciGPT-SciSciNet huggingface dataset:
NMR study of the stabilities of urea–formaldehyde resin components toward hydrolytic treatments

The solid residues of nine urea–formaldehyde (UF) resins after hydrolytic treatment at pH4 and 86°C for 20 h and the solid residues of one UF resin after eight different hydrolytic treatments were examined by 13C-CP–MAS NMR. The relative stability toward hydrolysis of each structural component in each UF resin was established for various hydrolytic conditions. In general, UF resins prepared from starting mixtures with a formal F/U molar ratio of 1.00 show a high degree of stability toward hydrolysis. Cross-linking methylene linkages in the UF resins show a higher susceptibility to hydrolytic treatments at pH 4 and 86°C than do linear methylene linkages. UF resins prepared with an F/U molar ratio of 2.00 are susceptible to hydrolysis at pH 4 and 86°C. Dimethylene ether linkages, methylols attached to tertiary amides, and poly(oxymethylene glycol) moieties are probably the main formaldehyde emitters in UF resin products. © 1994 John Wiley & Sons, Inc.
The separation and purification of enzymes through foaming

Abstract Mixtures of catalase and amylase are concentrated and purified through foaming. The relationship of the surface tension-concentration diagram to foam formation is examined. Various agents may be employed to control the foam separation process. A number of other enzymes subjected to foaming are found not to be inactivated. It is concluded that this process should be investigated further as a means of large-scale purification and concentration of enzymes.
Design, fabrication and characterization of a Far-field Superlens

The fabrication process as well as the optical characterization of a Far-field Superlens (FSL) is presented in detail. A FSL is capable of optically imaging well below the diffraction limit and works by enhancing and scattering evanescent waves to the far field which is then used to numerically reconstruct the object image [S. Durant, J. Opt. Soc. Am. B. 23(2006) 2383; Z. Liu, S. Durant, H. Lee, Y. Pikus, N. Fang, Y. Xiong, C. Sun, X. Zhang, Nano Lett. 7 (2007) 403]. We demonstrate the resolution of 70 nm gap distance of a three-line object in the far field. Also, a full optical imaging scheme, without the need for numerical processing, for a direct real-time subdiffraction-limited imaging is presented. Such remarkable imaging capability of FSL will revolutionize the optical imaging technique in the field of bio-imaging and nanolithography.
Syntactic Decision Rules for Recognition of Spoken Words and Phrases Using a Stochastic Automaton

This study deals with the design of a syntactic decision rule for recognizing an unknown utterance from a set X. The decision rule is expressed as a function of the character string (CS) derived from the test utterance. To obtain the CS, the waveform of the utterance is divided into a large number of frames of roughly equal duration numbered 1, 2,...,n. The ith symbol in the CS is the phonemic symbol obtained by subjecting the ith frame of the waveform to a relatively simple phoneme decision rule, the number of symbols in the CS being n. All the available nonacoustic information such as the lexicon of words in the set X, the possibility of confusion between different phonemes as seen by the phoneme decision rule, etc. is used in the design of the decision rule. The syntactic decision rule can be implemented by a stochastic finite state automaton involving limited memory and computation. The decision rule can also be interpreted as yielding the phrase x which minimizes a distance measure D(x, z) between the phrase x X and the observed CS z. We wili compare this approach with the other approaches such as the Viterbi methods, the distance approaches involving various types of distances, etc.
Tattoos Can Harm Perceptions: A Study and Suggestions.

Objective: Health researchers have claimed that perceptions toward a person with a tattoo are more negative than are perceptions toward nontattooed persons. However, support for this has been obtained almost completely by nonexperimental research. Participants: In 2 experiments with 158 community college student participants, the authors found that tattoos harmed perceptions. Methods: Students viewed a photograph of a female model with and without a visible tattoo, and rated her on 13 personal characteristics. Results: In Experiment 1, ratings of a model with a dragon tattoo were significantly more negative (p < .05) on 5 of the 13 personal characteristics than were ratings of the same model shown without the tattoo. In Experiment 2, which included different participants, a different model, and a different tattoo, the authors found that a dolphin tattoo led to more negative ratings on 2 of the 13 characteristics. Conclusions: The authors discuss possible impacts of tattoos on person perception as well as ...
THE ROLE OF ADVANCED AIR TRAFFIC MANAGEMENT IN REDUCING THE IMPACT OF AIRCRAFT NOISE AND ENABLING AVIATION GROWTH

Abstract Aviation is a critical component of the global economic infrastructure. If there is to be growth in aviation, however, the environmental impacts of aviation must be mitigated. While the benefits of advanced noise abatement procedures have been recognized, the primary obstacle to the implementation of these procedures remains the inability of air traffic controllers to maintain manually the precise sequencing and spacing required for maximum takeoff and landing rates in heavy traffic. Thus, introduction of automation that predicts the performance and noise impact of aircraft, and uses this information to assist the controller in determining and maintaining the appropriate sequencing and spacing, is critical to the successful utilization of noise abatement procedures.
Effect of a compliant fault zone on the inferred earthquake slip distribution

[1] We present a new semi-analytic method to evaluate the deformation due to a screw dislocation in arbitrarily heterogeneous and/or anisotropic elastic half plane. The method employs integral transformations to reduce the governing partial differential equations to the integral Fredholm equation of the second kind. Dislocation sources, as well as spatial perturbations in the elastic properties are modeled using equivalent body forces. The solution to the Fredholm equation is obtained in the Fourier domain using a method of successive over-relaxation, and is mapped into the spatial domain using the inverse Fast Fourier Transform. We apply this method to investigate the effect of a soft damage zone around an earthquake fault on the co-seismic displacement field, and on the earthquake slip distribution inferred from inversions of geodetic data. In the presence of a kilometer-wide damage zone with a reduction of the effective shear modulus of a factor of 2, inversions that assume a laterally homogeneous model tend to underestimate the amount of slip in the middle of the seismogenic layer by as much as 20%. This bias may accentuate the inferred maxima in the seismic moment release at depth between 3–6 km suggested by previous studies of large strike-slip earthquakes.
Narrowband dye laser with a large scan range

A computer-controlled nitrogen-pumped dye laser with a linewidth of 500 MHz and which is scannable linearly in wavelength over the full range of a dye (~50 nm) with a ±25-pm error is described. The computer couples the grating and etalon to scan large wavelength ranges while scanning the etalon over only one free spectral range at a time. A highly linear grating drive appropriate for echelle gratings is presented. Results with a piezoelectric scanned etalon and a pressure scanned etalon are shown. With the pressure scanned etalon a frequency stability of ±300 MHz/week has been achieved.
Coarse-Grained Simulations of Peptide Aggregation on Surfaces

We present a series of computational studies of peptide aggregation using a coarse-grained peptide model. Our model has one tunable parameter: the peptide backbone stiffness. We have found previously that this parameter governs the propensity of beta-sheet formation. By adjusting this parameter, we obtain a diversity of aggregate structures: amorphous/disordered aggregates, beta-barrels, multi-layered fibrils, and aggregates of mixed type. Here, we focus on peptide aggregation in the presence of three surfaces: the surface of a pre-existing fibril seed, a solid surface, and a lipid bilayer. (1) Seeding aggregation with compatible existing aggregates is known to remove the nucleation barrier for aggregation. We find the nature of both the aggregating peptides and aggregate seed affect the aggregation pathway and final aggregate structure. (2) Aggregation on solid hydrophilic or hydrophobic surfaces frequently occur in many experimental setups. We analyze the kinetics and thermodynamics of how these surfaces modulate the propensity toward the formation of highly-ordered fibrillar aggregates. (3) We simulate the aggregation of peptides on lipid bilayers in an effort to approximate the complexity of the cellular milieu. Our simulations uncover an important role of the fluidity of the membrane structure in governing the final morphology of the aggregates.Relevant publications:- J. Chem. Phys. 137, 145104 (2012)- J. Chem. Phys. 136, 065103 (2012)- J. Chem. Phys. 135, 085102 (2011)
Silicone gel and octamethylcyclotetrasiloxane [D4] enhances antibody production to bovine serum albumin in mice

The purpose of the present study was to determine whether components of silicone breast implants [silicon (polydimethylsiloxane) oil, silicone gel, and octamethylcyclotetrasiloxane (D4)] potentiate the antibody response to bovine serum albumin (BSA) in mice. Seventy A/J mice were divided into seven groups which received the following: group I--phosphate buffer solution (PBS); group II--20 centistoke (cs) silicone oil; group III--50% silicone gel homogenized in silicone oil; group IV--incomplete Freunds' adjuvant (IFA); group V--IFA mixed with an equal volume of silicone oil; group VI--D4; and group VII--IFA mixed with an equal volume of DA. Each 0.1 mL of treatment material(s) was mixed or emulsified with an equal 0.1-mL volume of 250 micrograms/mL BSA in PBS solution. Antibodies to BSA were measured using an enzyme-linked immunosorbent assay. Our study demonstrates for the first time that both D4 and the silicone gel potentiate antibody production to BSA in mice. Histopathologic evaluation of the injection sites reveals granulomas for mice injected with IFA and D4 preparations. Whether D4 or silicone gel acts as an adjuvant against self-antigens has yet to be determined.
Abnormalities in neural progenitor cells in a dog model of lysosomal storage disease.

Lysosomal storage disorders constitute a large group of genetic diseases, many of which are characterized by mental retardation and other neurologic symptoms. The mechanisms of neural dysfunction remain poorly understood. Because neural progenitor cells (NPCs) are fundamentally important to normal brain development and function, we investigated NPC properties in a canine model of mucopolysaccharidosis VII (MPS VII). MPS VII is a lysosomal storage disorder characterized by defects in the catabolism of glycosaminoglycans. NPCs were isolated from the olfactory bulb, cerebellum, and striatal subventricular zone of normal and MPS VII (β-glucuronidase-deficient) postnatal dog brains. Canine NPCs (cNPCs) from normal and MPS VII brains had similar growth curves, but cerebellar-derived cNPCs grew significantly slower than those derived from other regions. In differentiation assays, MPS VII cNPCs from the striatal subventricular zone and cerebellum generated fewer mature neuronal and/or glial cells than normal, and MPS VII olfactory bulb-derived cNPCs retained significantly more phenotypically immature cells. These differences were only present at the earliest time point after isolation; at later passages, there were no differences attributable to genotype. The data suggest that MPS VII cNPCs respond differently to developmental cues in vivo, probably because of the diseased neural microenvironment rather than intrinsic cellular deficits.
Reflections on the role of science in the evolution of dimensioning and tolerancing standards

Dimensioning and tolerancing standards originated about 75 years ago in the form of various national and company standards that governed engineering draughting and documentation practices. They served the purpose of communicating to manufacturers what geometric variations designers could tolerate in a product without compromising the product’s intended function. These standards have evolved over time and are by now well entrenched in the engineering profession throughout the world. For several initial decades, this evolution was driven primarily by codification of best engineering practices without the benefit of any systematic scientific treatment. This trend encountered a major hurdle in early 1980s when the emergence of computer-aided design and manufacturing systems forced a drastic reexamination of these standards with a greater emphasis on mathematical formalism. Since then, scientific principles to explain past practices and to guide future evolution have emerged, and the role of science has now be...
Abacavir/lamivudine fixed-dose combination antiretroviral therapy for the treatment of HIV

In the past 15 years, improvements in the treatment of HIV infection have dramatically reduced morbidity and mortality. Nucleoside reverse transcriptase inhibitors are the backbone of combination antiretroviral therapy for the treatment of HIV. One of the recommended and commonly used therapies in this class is the once-daily fixed-dose combination of abacavir/lamivudine. Clinical studies and practice have shown these drugs to be potent, safe, and easy to use in a variety of settings; however, several recent reports have challenged the safety and efficacy claims among certain patient populations, including those at risk for cardiovascular disease and in those with high viral loads prior to treatment initiation. We reviewed abacavir/lamivudine as a treatment for HIV and discussed limitations of its use due to these controversial issues.
ConceptClang: an implementation of C++ concepts in Clang

Concepts are a proposed C++ extension for constraints-based poly-morphism. In this paper, we present our experience implementing an infrastructure for exploring concept designs based on Clang--an LLVM frontend for the C family of languages. We discuss how the primary proposed features of concepts (such as concept-based lookup, overloading and constrained templates) are implemented in Clang, and how our implementation can be extended to support the different approaches suggested within the C++ community. Some illustrations are presented and include a subset of the Boost Graph Library.
Narratives of escape: A hermeneutic study of resiliency

This study examines the structure of narratives told by well-functioning adults who were “at-risk” as children. Participants told stories of their childhood based on pictures they selected from the TAT test (Thematic Apperception Test). Analysis of their narratives resulted in a set of hermeneutic rules which may be useful in interpreting the structure of narratives and in understanding the relationship between internalized images, reality construction, and resiliency. Two types of images were identified: negative images of stress and darkness and more positive images of escape and hope. Implications for helping clients develop images of strength and competence are discussed.
Venom alkaloids of fire ants in relation to worker size and age.

Abstract Piperidine alkaloids compose most of the venom of the red imported fire ant, Solenopsis invicta , and we examined how six of these alkaloids varied across worker size and age. In a colony sampled intensively, the relative abundance of each alkaloid was highly correlated with worker size with one exception, and ratios of saturated to unsaturated alkaloids were positively correlated with worker size. Similarly, both the abundance and ratios of alkaloids differed significantly between the small and large workers sampled from colonies across Texas, USA. Young and old workers produced less venom than ants of intermediate age (3–7 weeks), and ratios of saturated to unsaturated alkaloids increased significantly with worker age. The differences in venom composition correspond to the size- and age-based functional roles of workers.
Acoustic Imaging of Vapor Bubbles through Optically Non-Transparent Media

A preliminary investigation of the feasibility of acoustic imaging of vapor bubbles through optically non-transparent media is described. Measurements are reported showing the echo signals produced by air filled glass spheres of various sizes positioned in an aqueous medium as well as signals produced by actual vapor bubbles within a water filled steel pipe. In addition, the influence of the metallic wall thickness and material on the amplitude of the echo signals is investigated. Finally several examples are given of the imaging of spherical bubbles within metallic pipes using a simulated array of acoustic transducers mounted circumferentially around the pipe. The measurement procedures and a description of the measuring system are also given.
Can accretion onto isolated neutron stars produce gamma-ray bursts?

It is shown here that, if slow accretion onto high-velocity neutron stars from the interstellar medium is to be the origin of gamma-ray bursts, the accretion physics is very different from what applies for local low-velocity neutron stars. For halo neutron stars with high magnetic fields and velocities, electromagnetic dipole radiation pressure prevents accretion unless the period is longer than tens of seconds; the centrifugal barrier will then prevent accretion until the period reaches several thousand seconds. For periods as long as this, accretion may proceed through Kelvin-Helmholtz instability at the magnetopause boundary. At interstellar densities and neutron-star magnetic fields of about 10 exp 12 G, the accretion rate by this process can be much larger than the Bondi-Hoyle accretion rate, but is still well below what is needed for slow-accretion burst models. It is concluded that slow accretion onto high-velocity neutron stars in the halo cannot be the origin of gamma-ray bursts.
The Effect of Trans‐Stifle External Skeletal Fixation and Hyaluronic Acid Therapy on Articular Cartilage in the Dog

Transarticular external skeletal (TES) fixators were applied unilaterally to the stifle joints of 10 young adult dogs. After 4 weeks, the fixators were removed from all dogs. Two dogs were not allowed a remobilization period, whereas 8 dogs were provided with 4 additional weeks of weight-bearing activity in a kennel run. Four dogs were given high-molecular weight hyaluronic acid by intra-articular injection weekly during the remobilization period. Clinical gait evaluations and range of motion were determined during the remobilization period. Articular cartilage samples from both stifle joints of all dogs were evaluated histologically and histochemically. No significant differences in gait scores or range of motion were noted between treated and untreated dogs. Articular cartilage proteoglycan content was reduced after 4 weeks of trans-stifle external skeletal fixation as determined by loss of alcian blue (AB) histochemical staining. Improved homogeneity of histochemical staining was observed after remobilization. However, remobilization was associated with histological damage to the surface and tangential layers of articular cartilage. Remobilization combined with hyaluronic acid (HA) therapy improved histochemical staining and reduced structural damage to articular cartilage when compared with remobilization alone.
Rotatability of variance surfaces and moment matrices

Abstract Box-Hunter (Ann. Math. Statist. 28, 1957) state that the rotatability of a variance surface implies rotatability of the moment matrix M that defines the variance surface. We demonstrate by example that this implication breaks down when the matrix M is positive definite only, but not a moment matrix. We provide a detailed proof that the implication is correct when the matrix M is a positive definite moment matrix.
Polyvictimization in Developmental Context

Polyvictimization (i.e., exposure to multiple forms of victimization) appears highly correlated with indicators of traumatic stress in children. In this study, a national sample of children and youth were assessed for 36 different kinds of victimization using the Juvenile Victimization Questionnaire. Polyvictims were defined as the 10% of children experiencing the most different kinds of victimization in each of 4 developmental cohorts. The younger polyvictims had somewhat fewer victimizations overall, less sexual victimization, and more victimization at the hands of family members, particularly siblings. However, polyvictimization at every developmental level was strongly associated with distress symptoms. This study suggests the importance of assessing for and identifying polyvictims at all ages, including among preschoolers.
Sensory and Physicochemical Characteristics of Frankfurters Containing Lactate with Antimicrobial Surface Treatments

: Generally recognized as safe (GRAS) antimicrobial ingredients were applied to the surface of frankfurters with or without lactate to control the growth of Listeria monocytogenes and ensure the safety of ready-to-eat meat products. The sensory and physicochemical properties of the frankfurters were evaluated. Two frankfurter formulations with no potassium lactate (KL) or 3.3% KL were prepared, and each batch was treated for 30 s with 1 of 4 dips: (1) control (saline solution), (2) acidified calcium sulfate with propionic acid (ACSP), (3) 3.3% KL, or (4) 3.4% lactic acid. Samples then were vacuum-packaged, stored at 4.5°C for 12 wk, and evaluated at 2-wk intervals. The addition of KL slightly decreased aw and percent moisture in franks. Vacuum-package purge was slightly higher in samples treated with ACSP. Descriptive attribute sensory results indicated minimal effects on the sensory properties of the frankfurters containing KL and dipped in antimicrobial solutions.
Complete crystal field calculations including spin-orbit interaction and paramagnetic effects☆

Abstract Computational methods for carrying out complete crystal field calculations, including spin-orbit interaction and paramagnetic effects, on the Russell-Saunders S, L, J basis are presented for all d n systems. The equations employed for matrix elements are listed and symmetry considerations which simplify the calculations are applied for tetragonal complexes. The hole theorem is used to obtain results for d 10− n , n = 1, 2, 3, 4 systems. Paramagnetic susceptibilities and electron paramagnetic resonance g -factors are obtained by numerical differentiation and Boltzmann averaging. The methods provide several checks for accuracy and precision.
Progesterone-mediated increases of leucocyte alkaline phosphatase in rabbits

Abstract A study was carried out on the effects of various steroids on the activity of leucocyte alkaline phosphatase (EC 3.1.3.1) isolated from white male rabbits. Of numerous steroids administered, progesterone was the most effective, resulting in an average 17-fold increase in enzyme activity 24 h after administration. Actinomycin or puromycin administered simultaneously with progesterone blocked the increase in enzyme activity. When administered 6 or 24 h after progesterone, actinomycin or puromycin resulsted in a rapid decrease of enzyme activity. Examination of steroid structure and increased alkaline phosphatase activity indicated that among the steroids investigated an acetyl group at position 17, and a Δ3,4-keto group in the A ring produced greatest increases in leucocyte alkaline phosphatase activity.
Cigarette Smoke Induces Distinct Histone Modifications in Lung Cells: Implications for the Pathogenesis of COPD and Lung Cancer

Cigarette smoke (CS)-mediated oxidative stress induces several signaling cascades, including kinases, which results in chromatin modifications (histone acetylation/deacetylation and histone methylation/demethylation). We have previously reported that CS induces chromatin remodeling in pro-inflammatory gene promoters; however, the underlying site-specific histone marks formed in histones H3 and H4 during CS exposure in lungs in vivo and in lung cells in vitro, which can either drive gene expression or repression, are not known. We hypothesize that CS exposure in mouse and human bronchial epithelial cells (H292) can cause site-specific posttranslational histone modifications (PTMs) that may play an important role in the pathogenesis of CS-induced chronic lung diseases. We used a bottom-up mass spectrometry approach to identify some potentially novel histone marks, including acetylation, monomethylation, and dimethylation, in specific lysine and arginine residues of histones H3 and H4 in mouse lungs and H292...
Detection of Hα Emission in a Methane (T Type) Brown Dwarf

We report the detection of Hα emission in the T dwarf (methane brown dwarf) 2MASSW J1237392+652615 over three days using the Keck Low Resolution Imaging Spectrograph. The measured line flux, log (L_(Hα)/L_(bol)) = -4.3, is roughly consistent with early M dwarf activity levels and inconsistent with decreasing activity trends in late M and L dwarfs. Similar emission is not seen in two other T dwarfs. We speculate on several mechanisms that may be responsible for emission, including a strong magnetic field, continuous flaring, acoustic heat generation, and a close [α ~ (4–20)R_J] interacting binary, with the cooler component overflowing its Roche lobe. We suggest that the M9.5 Ve PC 0025+0447 could be a warm analog to 2MASS J1237+65 and may be powered by the latter mechanism.
Tracking low-precision clocks with time-varying drifts using kalman filtering

Clock synchronization is essential for a large number of applications ranging from performance measurements in wired networks to data fusion in sensor networks. Existing techniques are either limited to undesirable accuracy or rely on specific hardware characteristics that may not be available in certain applications. In this paper, we examine the clock synchronization problem in networks where nodes lack the high-accuracy oscillators or programmable network interfaces some previous protocols depend on. This paper derives a general model for clock offset and skew and demonstrates its application to real clock oscillators. We design an efficient algorithm based on this model to achieve high synchronization accuracy. This algorithm applies the Kalman filter to track the clock offset and skew. We demonstrate the performance advantages of our schemes through extensive simulations and real clock oscillator measurements.
The mitogenic activity of insulin: An intrinsic property of the molecule

Abstract Higher than physiological concentrations of insulin stimulate the incorporation of [ 3 H ]thymidine into DNA in a large variety of cells in culture. In order to exclude a contaminant of insulin preparations as responsible for this mitogenic action, porcine insulin was purified by reverse phase HPLC and assayed for mitogenic activity. HPLC- purified insulin had a mitogenic activity similar to that of impure insulin. Moreover, semisynthetic and synthetic insulins as well as HPLC-purified insulin derivatives such as monodesamido- and monoarginine insulin were also biologically active.
What's in a name?: experience architecture rearticulates the humanities

By describing cultural usability work as "information architecture," I knew I would be waging a continuous rearguard battle with database designers. Eventually the cost of bickering over turf outweighed the clarity the term brought, even considering its lineage. Richard Saul Wurman first recognized Information Anxiety in the late 1980s and described those working as Information Architects in the 1990s. Here, I remind readers that Wurman goes by the nickname "Ted." Wurman's vision of widespread attention to Technology, Education, and Design resulting in the popular TED talks---although he has an uneasy relationship with his own creation. "When he speaks about TED Talks, he clearly struggles to identify with the organisation today and is adamant that it has lost its vision." [http://www.universityobserver.ie/2012/10/31/interview-richard-saul-wurman-ted-talks/] At our current moment of media convergence, it helps to remember that the 20 minute flipped pedagogical lecture itself is the result of thirty years of dedication to disseminating disruptive ideas. If Ted Wurman can let TED go, I can let go of Information Architecture.
The Aglycone Specificity-determining Sites Are Different in 2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA)-glucosidase (Maize β-Glucosidase) and Dhurrinase (Sorghum β-Glucosidase)

The maize beta-glucosidase isozyme Glu1 hydrolyzes a broad spectrum of substrates in addition to its natural substrate DIMBOAGlc (2-O-beta-d-glucopyranosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-on e), whereas the sorghum beta-glucosidase isozyme Dhr1 hydrolyzes exclusively its natural substrate dhurrin (p-hydroxy-(S)-mandelonitrile-beta-d-glucose). To study the mechanism of substrate specificity further, eight chimeric beta-glucosidases were constructed by replacing peptide sequences within the C-terminal region of Glu1 with the homologous peptide sequences of Dhr1 or vice versa, where the two enzymes differ by 4 to 22 amino acid substitutions, depending on the length of the swapped regions. Five Glu1/Dhr1 chimeras hydrolyzed substrates that are hydrolyzed by both parental enzymes, including dhurrin, which is not hydrolyzed by Glu1. In contrast, three Dhr1/Glu1 chimeras hydrolyzed only dhurrin but with lower catalytic efficiency than Dhr1. Additional domain-swapping within the C-terminal domain of Glu1 showed that replacing the peptide (466)FAGFTERY(473) of Glu1 with the homologous peptide (462)SSGYTERF(469) of Dhr1 or replacing the peptide (481)NNNCTRYMKE(490) in Glu1 with the homologous peptide (477)ENGCERTMKR(486) of Dhr1 was sufficient to confer to Glu1 the ability to hydrolyze dhurrin. Data from various reciprocal chimeras, sequence comparisons, and homology modeling suggest that the Dhr1-specific Ser-462-Ser-463 and Phe-469 play a key role in dhurrin hydrolysis. Similar data suggest that DIMBOAGlc hydrolysis determinants are not located within the extreme 47-amino acid-long C-terminal domain of Glu1.
The distribution of prophenoloxidase and its activator in pupae of the Chinese Oak silkmoth, Antheraea pernyi

Abstract Freshly homogenized haemocytes of Antheraea pernyi pupae exhibited low phenoloxidase activity which rapidly increased at 0°C to a plateau. Thus, the enzyme appears to occur in the intact haemocytes, as it does in the blood plasma, as an inert precursor or prophenoloxidase. Of the total potential phenoloxidase activity in the blood, the haemocytes contained approximately 1 per cent. When moulting fluid was withdrawn from the body, this also underwent an increase in phenoloxidase activity. The ability of various preparations to accelerate the activation of prophenoloxidase was tested by adding them to freshly re-dissolved acetone powders of blood or plasma. At 0°C, homogenized haemocytes, as well as the re-dissolved acetone powders themselves, gradually developed the ability to accelerate the activation of prophenoloxidase. Homogenates of the fat body also exhibited activating ability. The activating principles proved to be non-dialysable and heatlabile. The activator probably occurs in the blood, at least, as an inert precursor or “proactivator”. When incubated at 0°C, the redissolved acetone powders of blood plasma also gave rise to a dialysable and heat-stable inhibitor. This factor retarded the activation of prophenoloxidase and lowered its final yield of enzymatic activity.
Blood Function in the Hydrothermal Vent Vestimentiferan Tube Worm

Extracellular hemoglobin in the whole blood of Riftia pachyptila has a high oxygen affinity (P50 = 1.8 millimeters of mercury at 3 degrees C), a moderate decrease in oxygen affinity at higher temperatures (P50 = 2.7 millimeters of mercury at 14 degrees C), a small effect of carbon dioxide on oxygen affinity (Delta log P50/Delta pH =-0.12), and a high oxygen carrying capacity (up to 11 milliliters of oxygen per 100 milliliters of blood). These characteristics are compatible with the high oxygen demand of chemoautotrophic metabolism in the variable vent environment.
A sparsity for decomposing a symmetric matrix

Abstract This paper studies a sparse configuration for a new class of decomposition derived by the author. Based upon the sparsity, the inverse of a sparse and symmetric matrix and the solution of a system of linear equations can be economically computed. Numerical examples are included.
Xanthogranulomatous colloid cyst of the third ventricle.

This is a case report of a xanthogranulomatous colloid cyst of the 3rd ventricle. Posible etiologies for this rare entiry, along with the clinical problems that may be associated with it, and the differential diagnosis are discussed.
Characterizing Graphs with Convex and Connected Cayley Configuration Spaces

We define and study exact, efficient representations of realization spaces Euclidean Distance Constraint Systems (EDCS), which include Linkages and Frameworks. These are graphs with distance assignments on the edges (frameworks) or graphs with distance interval assignments on the edges. Each representation corresponds to a choice of non-edge (squared) distances or Cayley parameters. The set of realizable distance assignments to the chosen parameters yields a parametrized Cayley configuration space. Our notion of efficiency is based on the convexity and connectedness of the Cayley configuration space, as well as algebraic complexity of sampling realizations, i.e., sampling the Cayley configuration space and obtaining a realization from the sample (parametrized) configuration. Significantly, we give purely graph-theoretic, forbidden minor characterizations for 2D and 3D EDCS that capture (i) the class of graphs that always admit efficient Cayley configuration spaces and (ii) the possible choices of representation parameters that yield efficient Cayley configuration spaces for a given graph. We show that the easy direction of the 3D characterization extends to arbitrary dimension d and is related to the concept of d-realizability of graphs. Our results automatically yield efficient algorithms for obtaining exact descriptions of the Cayley configuration spaces and for sampling realizations, without missing extreme or boundary realizations. In addition, our results are tight: we show counterexamples to obvious extensions. This is the first step in a systematic and graded program of combinatorial characterizations of efficient Cayley configuration spaces. We discuss several future theoretical and applied research directions. In particular, the results presented here are the first to completely characterize EDCS that have connected, convex and efficient Cayley configuration spaces, based on precise and formal measures of efficiency. It should be noted that our results do not rely on genericity of the EDCS. Some of our proofs employ an unusual interplay of (a) classical analytic results related to positive semi-definiteness of Euclidean distance matrices, with (b) recent forbidden minor characterizations and algorithms related to d-realizability of graphs. We further introduce a novel type of restricted edge contraction or reduction to a graph minor, a “trick” that we anticipate will be useful in other situations.
Effects of outer-shell orbitals on the hartree-fock energies

Abstract The inclusion of the outer-shell orbitals such as p-orbitals on hydrogen and d-orbitals on heavier main-group atoms is treated as a perturbation on Hartree-Fock orbital energies and total energies. It is shown that the first-order effect of the basis expanstion is to raise all the orbital energies. The first-orde correction to the total energy is shown to vanish identically. The differenct behavior of the CNDO approximation is mentioned.
Brain systems and long-term memory

This paper focuses mainly on those findings derived from lesion studies on the rat which help to identify ensembles of neural structures concerned with the expression of previously learned responses. At the outset, the use of the lesion method in the search for those neurological circuits underlying memory is defended. This is followed by an evaluation of neocortical and subcortical systems in long-term memory. Subsequently, a modest list of tentative functional neural "complexes" involved in the maintenance of certain classes of learned responses is given, based largely upon the author's own research. It is concluded that the key to the understanding of the neurological substrates of long-term memory lies in the identification of those subcortical sites which interact with neocortical sites in the performance of complex learned tasks. The most likely subcortical sites involved in this interaction appear to inhabit the regions of the basal ganglia, limbic midbrain area, and ventral portions of the brainstem reticular formation.
Quasi-Newton methods for image restoration

Many iterative methods that are used to solve Ax=b can be derived as quasi-Newton methods for minimizing the quadratic function 1/2 x T A T Ax-x T A T b. In this paper, several such methods are considered, including conjugate gradient least squares (CGLS), Barzilai-Borwein (BB), residual norm steepest descent (RNSD) and Landweber (LW). Regularization properties of these methods are studied by analyzing the so-called "filter factors". The algorithm proposed by Barzilai and Borwein is shown to have very favorable regularization and convergence properties. Secondly, we find that preconditioning can result in much better convergence properties for these iterative methods.
Ab initio based modeling of III-V semiconductor surfaces: Thermodynamic equilibrium and growth kinetics on atomic scales

We present a general methodology for developing predictive atomistic models of III-V semiconductor surfaces. We apply this methodology to the development of a kinetic Monte Carlo model that describes both equilibrium and growth of InAs(001) surfaces. Thermodynamic equilibrium behavior is solely based on ab initio density-functional theory calculations. Inclusion of kinetic processes and a large set of atomistic configurations on this highly complex surface enables the correct prediction of several experimental trends, including two thermodynamically stable surface reconstructions in the As-rich regime.
Investigation of strategies for executing sequential modular simulations

Abstract Alternative strategies for solving constrained and unconstrained steady state flowsheet problems using a sequential modular simulation system are studied. Test results obtained using six flowsheet problems of varying degree of nonlinearity indicate that the direct application of Broyden's method and of a successive linearization approach are closely competitive. Use of the identify matrix to initialize Broyden's method and a simple step size control strategy proved preferable to perturbation based approximations. Diagonal approximations are desirable in initializing the constraint equation contributions to the composite Jacobian. Simple separator/stoichiometric reaction linear models also were found to be preferable to more elaborate perturbation based linearized models. Because of the overheads associated with solving the linearized flowsheet model, the linearization strategy appears worthwile primarily for CPU time intensive simulations. All tests in this study were performed using the LSP flowsheeting system. The linearized subproblems were solved using the LINBAL package.
A molecular mechanism for electrical tuning of cochlear hair cells

Cochlear frequency selectivity in lower vertebrates arises in part from electrical tuning intrinsic to the sensory hair cells. The resonant frequency is determined largely by the gating kinetics of calcium-activated potassium (BK) channels encoded by the slo gene. Alternative splicing of slo from chick cochlea generated kinetically distinct BK channels. Combination with accessory β subunits slowed the gating kinetics of α splice variants but preserved relative differences between them. In situ hybridization showed that the β subunit is preferentially expressed by low-frequency (apical) hair cells in the avian cochlea. Interaction of β with α splice variants could provide the kinetic range needed for electrical tuning of cochlear hair cells.
Ruthenium in glass-forming borosilicate melts

Abstract Ruthenium was added to a borosilicate melt system and the amount dissolved investigated as a function of the ruthenium dopant, amount of ruthenium dopant, redov additives, time, melt atmosphere, and melt temperature. The amount of dissolved ruthenium in all cases was less than about 0.001 wt.%, the approvimate limit of detection. Insoluble ruthenium diovide RuO 2 was always found to be present in the glasses. The previous results of Muckerji, which typically indicated hundreds of parts per million of ruthenium dissolving in borosilicate and silicate glass melts, could not be substantiated.
The esterolytic activity of serum albumin

Abstract Crystalline bovine serum albumin catalyzes the hydrolysis of β-naphthyl esters of both long- and short-chain fatty acids as well as tripalmitin. Esterolytic activity was also found with crystalline human serum albumin and with the Fraction-V serum albumins of the dog, pig and horse. The substrate specificity patterns varied with species. It was not possible to separate the enzymic activity from the albumin by chromatography on DEAE-cellulose. The question of whether the esterolytic activity is a property of the albumin protein or a contaminant is discussed.
“Lady Teachers” and the Genteel Roots of Teacher Organization in Gilded Age Cities

May the work of the L.T.A. go on ever upward and onward-gaining ground year by year; so that in future it will have its voice in the community, not low & sweet-but clear and resonant showing power and strength; may it gain that strength by increased membership, held together by strong bonds of love. Let us then be up and doing, With a heart for any fate; Still achieving, still pursuing Learn to labor and to wait.1 Miss Ophelia S. Newell believed that teachers occupied a public office of unappreciated responsibility. As the secretary of the Lady Teachers' Association (LTA) in Boston, she penned these hopeful remarks as a coda to her 1875 annual report, borrowing the last stanza of a popular Henry Wadsworth Longfellow poem. For Newell and her fellow teachers, “learn to labor and to wait” underscored their steadfast commitment to the schools. They founded the association attempting to bring women teachers “nearer together in sympathy and friendship and also for a mutual benefit in debate and parliamentary rules.” Frustrated with being “accused of a lack of enthusiasm in our profession,” they hoped such criticism could “be remedied by an organization of this kind.” Honing their debating skills represented one of the women's objectives, but they aspired to do more than polish their chances for professional advancement.
The Walls Came Tumbling Up: The Production of Culture, Class and Native American Societies

In this paper, two historical moments in the continual formation of Native American societies are examined: the creation of distinct and bounded ‘Indian’ societies in the south-eastern colonial United States, and the recent internal differentiation of the Lumbee Indian peoples in North Carolina. Four issues are at stake: the production of difference and inequality within and between Native American societies; the formation and transformation of ‘culture’ in this context; a re-examination of the concept of class; and the simultaneous production of culture and class among indigenous peoples and perhaps more generally. This leads to a suggestion concerning the problem of hegemony in struggles over inequality.
Various Oils and Fats as Substitutes for Butterfat in the Ration of Young Calves

Summary Feeding tests were conducted to compare the feeding value of the following fats and oils for calves: butterfat, lard, tallow, coconut oil, peanut oil, corn oil, cottonseed oil and soybean oil. The effect of a very fat-poor diet on calves was also determined. Each oil or fat was added to skim milk, homogenized to form a product containing 3.5 per cent fat and fed along with a low fat content concentrate mixture, cod liver oil and some alfalfa hay. One control group was fed normal whole milk not homogenized. Test periods ranged from a few days to about six months. In average daily gain in weight as well as in general well-being, the calves fed butterfat excelled those in all other groups. Following closely were those receiving lard and tallow. Corn oil, cottonseed oil and soybean oil were the least satisfactory. The average daily gains of calves in the latter three groups were .40 pound, .31 pound and .32 pound, respectively. They appeared unthrifty, listless and emaciated. Some calves in these groups died and others were saved only by changing to whole milk. Post mortem examinations showed considerably more fat deposited in calves fed butterfat than in those that had been fed other oils and fats.
Culture Confronts Nature in the Dialectical World of the Tropics

AVENI AND URTON are to be congratulated for organizing a conference 1 V that, for the first time, has brought together scholars from various disciplines to discuss the ethnoastronomy and archaeoastronomy of the American tropics. We have had to converse across disciplinary boundaries and I hope that the endeavor has clarified some of the concepts, methods, and perspectives of the different specialities represented. As an anthropologist, I would like to suggest that the tropics provide a perceptual environment that promotes and enhances a particular 'science of the concrete,'1 whereby perceived order in the environment is the basis for systems of classificatio ns, epistemological structures, and cosmologies. In the American tropics, the science of the concrete takes on a particular character that results in epistemologies founded in what I will call dialectical, reversible dualism. The native philosophers of the indigenous societies under discussion engage in the study of the nature and limits of knowledge. Their epistemological reflections are embedded in religious and ritual practices. Moreover, the native philosophers, who are usually shamans or astronomer-priests, use methods and metaphorical language that are unfamiliar to us. More importantly, the logic that underlies these systems of knowledge is dialectical rather than rationalistic. As Roy Wagner has pointed out in The Invention of Culture, the anthropological definition of the concept of dialectic refers to a tension or dialogue-like alternation between two conceptions or viewpoints that are simultaneously contradictory and supportive of each other.
Electrical conductivity of additively colored potassium chloride

Abstract The conductivity of colored KCl crystals was found to be greater than that of uncolored crystals over the range from 150° to 550°C. The electronic transport number, determined to be 0.96 at 400°C, indicates that the increased conductivity was due to ionized F centers. Plots of log σ vs. 1000 T were linear, with two different slopes depending on the prior treatment of the sample. If gold contacts were evaporated onto freshly cleaved crystals rectification was observed. The rectification could be eliminated by either heating the colored crystals for five minutes at temperatures greater than approximately 500°C, after applying the contacts, or by sanding the crystals prior to applying the contacts. Accompanying the elimination of rectification was a decrease in the conductivity and an increase in the activation energy for conduction, from 1.13 to 1.22 eV. Curves of σ, at a given temperature, vs. √ n F were found to be linear. From the above observations and the theory of rectifying contacts, the thermal ionization energy for F centers was calculated to be not less than 2.04 eV. Comparison of the calculations with experiment lead to the conclusion that the concentration of negative-ion vacancies in colored crystals was much less than the equilibrium concentration in uncolored crystals.