cssi/SciSciGPT-SciSciNet huggingface dataset:
Multifrequency radiation diffusion equations for homogeneous, refractive, lossy media and their interface conditions

Abstract We derive time-dependent multifrequency diffusion equations for homogeneous, refractive lossy media. The equations are applicable for a domain composed of several materials with distinct refractive indexes. In such applications, the fundamental radiation variable, the intensity I, is discontinuous across material interfaces. The diffusion equations evolve a variable ξ, the integral of I over all directions divided by the square of the refractive index. Attention is focused on boundary and internal interface conditions for ξ. For numerical solutions using finite elements, it is shown that at material interfaces, the usual diffusion coefficient 1 / 3 κ of the multifrequency equation, where κ is the opacity, is modified by a tensor diffusion term consisting of integrals of the reflectivity. Numerical results are presented. For a single material simulation, the ξ equations yield the same result as diffusion equations that evolve the spectral radiation energy density. A second simulation solves a test problem that models radiation transport in a domain comprised of materials with different refractive indexes. Results qualitatively agree with those previously published.
Research based methods for using powerpoint, animation, and video for instruction

This paper is a literature review on practical techniques and guidelines using PowerPoint, animation, and video effectively for instruction. The motivation to collect research based guidelines for the creation and use of instructional media comes from Giordano and Trufant's observation that one of the common barriers that prevent faculty from successfully integrating technology into their teaching is a "lack of familiarity with best practices, knowledge, and research on the appropriate uses of technology in the classroom" [1]. This paper would be of interest to faculty and instructional technology staff who support faculty in the development of instructional media.
Ultrastructure of a craniopharyngioma.

A craniopharyngioma removed at surgery was examined by light and electron microscopy. The tumor consisted of both solid and cystic components. The cells lining the cysts, as well as those forming the solid masses, displayed desmosomes, tonofilaments, keratohyalin granules, and keratinization identical to those seen in the epidermis. Three distinct varieties of cysts were recognized in this tumor. The cysts occurring within the connective tissue stroma were lined by a row of cells with basement membrane covering. The cysts in the epithelial masses, on the other hand, were lined either by the slender processes of the stellate-shaped cells with a reticulated surface coating, or by cells showing microvillous projections and frequent keratinization. Crystalline calcium deposits were present, predominantly in the keratinized zones. Furthermore, the tumor extended to the hypothalamic region evoking severe reactive gliosis with formation of Rosenthal fibers which consisted of masses of granular deposits within the astrocytic processes.
Variance Calculations for Direct Adjusted Survival Curves, with Applications to Testing for No Treatment Effect

Several investigators have recently constructed survival curves adjusted for imbalances in prognostic factors by a method which we call direct adjustment. We present methods for calculating variances of these direct adjusted survival curves and their differences. Estimates of the adjusted curves, their variances, and the variances of their differences are compared for non-parametric (Kaplan-Meier), semi-parametric (Cox) and parametric (Weibull) models applied to censored exponential data. Semi-parametric proportional hazards models were nearly fully efficient for estimating differences in adjusted curves, but parametric estimates of individual adjusted curves may be substantially more precise. Standardized differences between direct adjusted survival curves may be used to test the null hypothesis of no treatment effect. This procedure may prove especially useful when the proportional hazards assumption is questionable.
What Does Silicon Valley Have to Do with Jerusalem

Abstract. Adapted from the introductory chapter of Minding God: Theology and the Cognitive Sciences (Peterson 2003), I here lay out a general approach for a dialogue between theology and cognitive science. Key to this task is an understanding of theology as the science or study of meaning and purpose. I give reasons why theology should be thought of in this sense and the potential fruitfulness of this approach.
DEVS formalism and methodology: unity of conception/diversity of application

DEVS (Discrete Event System Specification) is a general modelling formalism with sound semantics founded on a system theoretic basis. This gives it a claim to be universal for formalisms describing Discrete Event Dynamic Systems (DEDS). This gives that any other formalism such as Petri nets, which have become very popular for DEDS control can be embedded in it. Moreover, DEVS extends to the continuous case thus facilitating combined discrete/continuous modelling. The universality of DEVS is significant because it has been implemented in a variety of simulation environments, as extensions of diverse underlying Object-Oriented languages such as CLOS and C++. This gives it not only the power of formal rigor but also the practical capability of application to real world complex systems. The DEVS formalism has associated with it a characteristic abstract simulation engine architecture that can be realized in diverse sequential and parallel/distributed platforms. It is especially suitable for the simulation study of complex technical and natural systems with intelligent components and for long term model development capability acquired through systematic reusability. This tutorial will present the basic concepts of the DEVS formalism and its associated simulation methodology. These concepts will be illustrated in the context of large scale ecosystems modelling.
Micromachining process simulation using a continuous cellular automata method

In this paper, we present results on the development of an anisotropic crystalline etching simulation (AGES) program based on a continuous cellular automata (CA) model. The program provides improved spatial resolution and accuracy compared with the conventional and stochastic CA methods. Implementation of a three-dimensional (3-D) dynamic CA technique provides increased simulation speed and reduced memory requirement. The first AGES software based on common personal computer platforms has been realized for simulation of micromachining processes and visualizing results in 3-D space. The software is uniquely capable of simulating the resultant profile following a series of micromachining steps, including surface passivation, reactive ion etching, as well as wet chemical bulk etching. A novel method for accurately obtaining the etch-rate diagram of anisotropic etching using both experimental and numerical techniques has been developed.
KINETICS OF SOIL NITROGEN MINERALIZATION FROM UNDISTURBED AND DISTURBED SOIL

Knowledge of soil nitrogen (N) mineralization processes is essential for modeling soil processes in agriculture. Many authors have found discrepancies in N mineralization between disturbed and undisturbed samples. Nevertheless, most simulation models use a first-order kinetic model (exponential model) for all the layers under study, devised from studies using disturbed and superficial samples. The goal of the present study was to establish the best kinetic model to explain and predict N mineralization as affected by sample disturbance and soil depth in two soils of the semiarid region of Argentina. Disturbed (D: sieved <2 mm and quartz mixed) and undisturbed (UD) samples from two Haplustolls were subject to successive incubations and extractions to assess N mineralization rates. The amount of N mineralized in disturbed samples was up to 200% greater than undisturbed. Replicate D samples from the Torriorthentic had significantly higher variability than samples from the Torrifluventic. In the latter, UD sam...
Proteomic analysis of the site specificity of glycation and carboxymethylation of ribonuclease.

Proteomic analysis using electrospray liquid chromatography−mass spectrometry (ESI−LC−MS) has been used to compare the sites of glycation (Amadori adduct formation) and carboxymethylation of RNase ...
Loss of the Chance of Cure from Cancer

In Gregg v Scott' the agreed facts were few. On 22 November 1994 Mr. Gregg presented to Dr Scott complaining of a lump under his left arm. In breach of his duty to Mr. Gregg, Dr Scott failed to refer him at once for biopsy investigation or to arrange to see him very soon to see if the lump had resolved itself. Had he done so, the lump would have been revealed to be cancerous and cancer treatment would have commenced in April 1995. The breach meant that the cancer went undetected until November 1995 and cancer treatment commenced in January 1996; the breach had caused a 9 month delay before treatment commenced. In this 9month period, the cancer spread to the left pectoral region. The details of treatment are important. From January 1996 chemotherapy and radiotherapy were administered but, although the tumour responded, it did so incompletely. As a result aggressive high dose chemotherapy was administered in August 1996. In early 1998 Mr. Gregg suffered a relapse, that is a new tumour was detected in the right axilla. The medical conclusion from this relapse was that he could not be "cured", that is survive for at least 10 years without evidence of the disease. Palliative therapy was administered. In April 1998 there was another suspected relapse and a further course of palliative therapy was administered. From April 1998 to the date of judgment in the trial on 3 August 2001, and on to the time when judgment was handed down by the House of Lords on 27 January 2005 there was no discernible recurrence of the disease: Mr. Gregg was in remission throughout. In Gregg the pre-tort range of fates confronting a cohort of 100 people with the same cancer as Mr. Gregg's and undergoing initial treatment were assessed at trial 2 as:
Mental juggling: when does multitasking impair reading comprehension?

ABSTRACTThe present study investigated the conditions under which multitasking impairs reading comprehension. Participants read prose passages (the primary task), some of which required them to perform a secondary task. In Experiment 1, we compared two different types of secondary tasks (answering trivia questions and solving math problems). Reading comprehension was assessed using a multiple-choice test that measured both factual and conceptual knowledge. The results showed no observable detrimental effects associated with multitasking. In Experiment 2, the secondary task was a cognitive load task that required participants to remember a string of numbers while reading the passages. Performance on the reading comprehension test was lower in the cognitive load conditions relative to the no-load condition. The present study delineates the conditions under which multitasking can impair or have no effect on reading comprehension. These results further our understanding of our capacity to multitask and have p...
Limbic dysregulation is associated with lowered heart rate variability and increased trait anxiety in healthy adults.

Objectives: We tested whether dynamic interaction between limbic regions supports a control systems model of excitatory and inhibitory components of a negative feedback loop, and whether dysregulation of those dynamics might correlate with trait differences in anxiety and their cardiac characteristics among healthy adults. Experimental Design: Sixty-five subjects received fMRI scans while passively viewing angry, fearful, happy, and neutral facial stimuli. Subjects also completed a trait anxiety inventory, and were monitored using ambulatory wake ECG. The ECG data were analyzed for heart rate variability, a measure of autonomic regulation. The fMRI data were analyzed with respect to six limbic regions (bilateral amygdala, bilateral hippocampus, Brodmann Areas 9, 45) using limbic time-series cross-correlations, maximum BOLD amplitude, and BOLD amplitude at each point in the time-series. Principal Observations: Diminished coupling between limbic time-series in response to the neutral, fearful, and happy faces was associated with greater trait anxiety, greater sympathetic activation, and lowered heart rate variability. Individuals with greater levels of trait anxiety showed delayed activation of Brodmann Area 45 in response to the fearful and happy faces, and lowered Brodmann Area 45 activation with prolonged left amygdala activation in response to the neutral faces. Conclusions: The dynamics support limbic regulation as a control system, in which dysregulation, as assessed by diminished coupling between limbic time-series, is associated with increased trait anxiety and excitatory autonomic outputs. Trait-anxious individuals showed delayed inhibitory activation in response to overt-affect stimuli and diminished inhibitory activation with delayed extinction of excitatory activation in response to ambiguous-affect stimuli. Hum Brain Mapp 2009. © 2007 Wiley-Liss, Inc.
The evaluation of a company supplied ordering policy (COP) applied to purchase discounts

Abstract This article describes the operation and performance of a company supplied ordering policy used in the multiple purchase discounts framework when the discount is for all units purchased. The ordering policy is used to order raw materials and purchased components within the material requirements planning environment, and was incorporated into a simulation model which used real product discount structures to generate cost data. The model also considered the condition of multiple purchase discounts and demand uncertainty. This simple company ordering policy, while not the best performer, did surprisingly well in this environment as demonstrated by the supporting evidence from the simulation.
Parents' descriptions of objects: Potential data for children's inferences about category principles☆

Abstract In generalizing from an individual object, humans expect some features of the object (e.g., a dog's fur or heart), but not others (e.g., the dog's collar or owner), to be present in other category members. Little is known about how people come to make such distinctions among properties, or about the relative influence of a priori constraints versus knowledge gained through experience. This research begins to work out these relative effects by focusing on parents' speech as a source of information for children in identifying valid inferences. Parents were given a set of pictures and asked to teach their 2- to 4-year-old children about categories at different hierarchical levels: basic (e.g., porcupine), superordinate (e.g., vehicle), and subordinate (e.g., monkey wrench) levels. Object descriptions differed at the three levels. Parents mentioned perceptual features and parts more often when discussing basic and subordinate categories, while they related more abstract functions when discussing superordinate categories. These differences could help children to pick out generalizable properties, since parents are emphasizing the properties that are typical of the category. Parents also may help children learn about the asymmetrical way that inferences are made within hierarchies, by anchoring general statements (“machines do work for us”) with examples of how these properties would apply at more specific levels (“lawnmowers do work outside, mixers do work in the kitchen…”). The results are discussed in terms of possible ways in which children may use parents' descriptions as a source of data for their developing inferential abilities.
Derivation of the complete msp4 gene sequence of Anaplasma marginale without cloning

The gene encoding MSP4, a 31-kDa surface protein of the rickettsia Anaplasma marginale, was completely sequenced without prior cloning of the gene. Degenerate oligodeoxyribonucleotides (oligos) corresponding to the N-terminal amino-acid sequence of MSP4 were used as primers in the polymerase chain reaction (PCR) to amplify a 65-bp fragment of which the central 32 bp was nondegenerate. The 32-bp probe was hybridized to restriction enzyme-digested, genomic A. marginale DNA in Southern blots, and the hybridizing fragment was size selected from agarose gels and ligated into the Bluescript II SK (+/-) plasmid. The ligation reaction mixture was used as a template for PCR, amplified from the 32-bp oligo or its inverse complement to plasmid sequences. The PCR products were sequenced to obtain the entire msp4 gene and surrounding regions. This method of sequencing a gene without previously obtaining a clone for that gene could be beneficial in situations where conventional cloning and screening strategies are inefficient or ineffective.
Adolescent Reasoning about Advertisements: Relevance of Product Claims:

To foster generalization of science education from the classroom to other important problems we investigate how adolescents reason about scientific claims in advertisements. We administered interviews to 88 seventh and eighth graders to assess their criteria for brand decision making and to determine whether they use these criteria when assessing claims in advertisements. We found that adolescents change their product criteria frequently, that they lose track of their own criteria when confronted with advertisers' claims and that advertisements may encourage adolescents to add criteria to those they consider when making brand decision. Implications include the potential for impaired decision making due to an information overload and the possibility that adolescents may adopt social-psychological criteria which when not fulfilled could lead to loss of self-esteem.
An Environmental Interaction Model for Agency Development in Adult Education

This article presents an environmental interaction model for agency development in adult education. Agency development is defined in terms of quantitative growth. Development is conceptualized as b...
Identifying and characterizing epitaxial graphene domains on partially graphitized SiC(0001) surfaces using scanning probe microscopy

Scanning tunneling microscopy (STM), atomic force microscopy (AFM), lateral force microscopy (LFM), and conductive AFM (cAFM) are employed to characterize epitaxial graphene on SiC(0001). Of particular interest are substrates that possess single-layer and bilayer graphene domains, which form during thermal decomposition of silicon from SiC(0001). Since these samples are often partially graphitized, characterization techniques are needed that can distinguish domains of epitaxial graphene from the adjacent (6√3×6√3)R30° reconstructed SiC(0001) surface. The relative merits of STM, AFM, LFM, and cAFM for this purpose are outlined, thus providing nanometer-scale strategies for identifying and characterizing epitaxial graphene.
Calmodulin Regulation of Drosophila Light-Activated Channels and Receptor Function Mediates Termination of the Light Response In Vivo

Calmodulin (CAM) participates in a variety of intracellular transduction processes by modulating signaling molecules in response to calcium changes. We report the characterization of Drosophila Cam mutants and the role of CAM in photoreceptor cell function. Contrary to current models of excitation and TRP channel function, we demonstrate that the transient phenotype of trp mutants can be explained by CAM regulation of the TRPL channel rather than by the loss of a store-operated conductance leading to depletion of the internal stores. We also analyzed light responses in a variety of mutant and transgenic backgrounds and demonstrate the importance of calmodulin in mediating calcium-dependent negative regulation of phototransduction. Our results show that CAM coordinates termination of the light response by modulating receptor and ion channel activity.
SU‐FF‐I‐137: Scatter Correction in Quantitative Dual Energy Mammography

Purpose: To investigate the performance of a new algorithm designed to correct x‐ray scatter and estimate the primary intensity in mammography.Method and Materials: The algorithm is based on image convolution and implements a spatially variant scatter point spread function which is energy and thickness dependent. The scatter kernel was characterized in terms of its scattering fraction and radial extent on uniform PMMA phantoms with thicknesses of 0.8 – 8.0 cm. The algorithm operates on a pixel by pixel basis by grouping pixels of similar thicknesses into a series of mask images that are then individually deconvolved using Fourier image analysis with a distinct kernel for each image. The algorithm was tested with four experimental phantoms, three step phantoms made of PMMA and one anthropomorphic breast phantom on a full field digital mammography system at energies of 24, 28, 31, and 49 kVp. The true primary signal was measured with a multi hole collimator.Results: For all 16 studies, the average mean percentage error in estimating the true primary signal was found to be −2.13% and the average rms percentage error was 2.60%. Conclusion: The new algorithm allows improved accuracy in estimating primary image intensity. It is also expected to improve the accuracy of quantitative dual energy mammography.
High precision active nutation control of a momentum biased spacecraft with flexible appendages

The controller design for the Solar Dynamics Observatory, a momentum biased spacecraft with three flexible appendages, is presented. The pointing of scientific instruments imposes arc-second pointing requirements on the spacecraft bus and meeting these requirements necessitates the use of an active nutation controller, here mechanized with a small reaction wheel oriented along a bus transverse axis. The active nutation controller does its job by orchestrating the transfer of angular momentum out of the bus transverse axes and into the momentum wheel. A simulation study verifies that the controller provides quick, stable, and accurate response.
The fate of transplanted cells in mouse blastocysts in vitro.

Four-day synchronous blastocyst donor cells and 8- and 12-day asynchronous embryonic cells were transplanted adjacent to and within the inner cell mass of four-day recipient blastocysts. Virtually all recipient blastocysts tolerated micrurgical procedures and regained their “normal” size and shape after four hours of incubation. About 3% of all recipient blastocysts exhibited rejected cells. The nuclei of the transplanted cells, labeled with tritiated thymidine, appeared to be present in various phases of the cell cycle 20 hours after transplant. After 40 hours in culture, the number of labeled cells was significantly greater than the number of cells transplanted in both the synchronous and asynchronous transplants. The present study shows for the first time that chronologically older cells can divide in a younger embryo and suggests that they participate in the structure of the recipient embryo.
The Effect of Amino Acid Substitutions in the Conserved Aromatic Region of Subunit II of Cytochrome c Oxidase in Saccharomyces cerevisiae

Mitochondrial encoded subunit II of cytochrome c oxidase carries the metal center, which acts as the initial acceptor of electrons from cytochrome c. Among the conserved features of this protein is a region in which five aromatic and three non-aromatic amino acids are conserved in a wide variety of organisms. This aromatic region has been postulated to be involved in transfer of electrons from the copper center in subunit II to the remaining metal centers of cytochrome oxidase in subunit I. To test the functional importance of two conserved, aromatic tryptophan residues and one conserved, non-aromatic glycine residue, yeast strains with alterations at these positions were characterized. The strains with altered codons were tested for their ability to carry out cellular respiration, for their growth rates on non-fermentable carbon sources, and for their cytochrome c oxidase activity. The results demonstrate that the aromatic character of the tryptophan residues appears necessary for subunit II function, while the conserved glycine can be replaced with other, small, uncharged residues.
Ectopic human chorionic gonadotropin in breast carcinoma.

Immunoreactive human chorionic gonadotropin (hCG) was found in 9 of 65 surgically removed malignant breast tumors. Concentrations ranged from 5 to greater than 500 mIU hCG/g tumor. hCG was measured by a β-chain specific radioimmunoassay. In further study of these specimens, an immunoperoxidase staining technique was used to stain for hCG in formalin-fixed sections. The hCG was shown to be localized within the cytoplasm and on the surface of the malignant cells.
Photosynthetically Mediated Zn Removal from the Water Column in High Ore Creek, Montana

We collected cobbles covered in biofilm from High Ore Creek, Montana, placed them in 12 transparent PVC plastic chambers, and exposed the chambers to four treatments: Sunlight, Sunlight-occluded, DCMU (photosynthesis inhibited), and Formalin. Total aqueous zinc (Zn) concentrations in the Sunlight treatment decreased during the 4-h experiment and were significantly lower (P ≤ 0.05) than in the other three treatments, in which the total aqueous Zn concentrations did not decrease significantly. Therefore, we believe photosynthesis in the biofilm played a role in causing total aqueous Zn concentrations in the Sunlight treatment to decrease, and we believe a similar process contributes to diel Zn cycling in High Ore Creek and some other metals-contaminated streams.
Density matrix treatment of non-adiabatic photoinduced electron transfer at a semiconductor surface.

Photoinduced electron transfer at a nanostructured surface leads to localized transitions and involves three different types of non-adiabatic couplings: vertical electronic transitions induced by light absorption emission, coupling of electronic states by the momentum of atomic motions, and their coupling due to interactions with electronic density fluctuations and vibrational motions in the substrate. These phenomena are described in a unified way by a reduced density matrix (RDM) satisfying an equation of motion that contains dissipative rates. The RDM treatment is used here to distinguish non-adiabatic phenomena that are localized from those due to interaction with a medium. The fast decay of localized state populations due to electronic density fluctuations in the medium has been treated within the Lindblad formulation of rates. The formulation is developed introducing vibronic states constructed from electron orbitals available from density functional calculations, and from vibrational states describ...
Repair of near-visible- and blue-light-induced DNA single-strand breaks by the CHO cell lines AA8 and EM9.

The induction of single-strand breaks (SSB) and the kinetics of SSB repair were measured in two Chinese hamster ovary cell lines irradiated with monochromatic photons of near-visible radiation (405 nm) and blue light (434 nm). The radiosensitive and UV-A-sensitive mutant line EM9 is known to repair SSB induced by ionizing radiation or 365-nm UV-A more slowly than the parent line AA8. At the 10% survival level, EM9 cells were 1.7- and 1.6-fold more sensitive than AA8 cells to 405 and 434 nm radiation, respectively. This sensitivity was not due to differences in induction of SSB because AA8 and EM9 cells accumulated the same number of initial breaks when irradiated at 0.5°C with either 405 nm (5.9 SSB per MJ/m2) or 434 nm (5.1 SSB per MJ/m2), as measured by alkaline elution. When the cells repaired these SSB at 37°C in full culture medium, biphasic repair kinetics were observed for both cell lines. In both phases of repair, EM9 cells repaired breaks induced by both wavelengths more slowly than did AA8 cells. The 1½ values for the repair phases for 405-nm-induced SSB were 3.8 and 150 min for EM9, and 1.5 and 52 min for AA8; the corresponding values for repair of 434 nm breaks were 3.7 and 39 min for EM9, and 2.0 and 30 min for AA8. Because of this slower repair, EM9 cells left more SSB unrepaired after 90 min than did AA8 cells for both wavelengths. The ratio of unrepaired breaks in EM9 cells to that in AA8 cells was 1.4 and 1.7 times higher for 405 and 434 nm radiation, respectively. Thus, the sensitivity of EM9 cells to near-visible and visible light correlates with a deficiency in repairing SSB induced by these wavelengths. These results suggest that DNA damage may be a critical event in visible-light-induced cellular lethality and that an important determinant of the ability of AA8 and EM9 cells to survive visible light irradiation may be their ability to repair DNA strand breaks.
Gamma-irradiation Sterilization in an Inert Environment: A Partial Solution

Background In the mid to late 1990s, to sterilize UHMWPE bearings, manufacturers changed from gamma-irradiation-in-air (gamma-air) sterilization, which initiated oxidation leading to bearing fatigue, to gamma-irradiation sterilization in an inert environment (gamma-inert). The change to gamma-inert sterilization reportedly prevented shelf oxidation before implantation but not in vivo oxidation.
Grazer species effects on epilithon nutrient composition

Summary 1. Field and laboratory experiments were conducted to investigate the excretion stoichiometry of nitrogen (N) and phosphorus (P) of two benthic macroinvertebrate grazers, the crayfish Orconectes propinquus and the snail Elimia livescens, that differ in body stoichiometry (mean body molar N : P 18 and 28, respectively). Crayfish excretion had a significantly higher ammonium : soluble reactive phosphorus (SRP) ratio in the laboratory and in three natural streams than did snails, as predicted by ecological stoichiometry theory. 2. In greenhouse recirculating artificial streams, treatments consisting of crayfish, snails, or no grazers were used to examine responses in dissolved nutrient concentrations and epilithon nutrient composition and limitation. SRP concentrations depended upon the grazer species, with the snail treatment having a higher SRP concentration than other treatments (P < 0.05). Dissolved inorganic N was not affected by grazers, but appeared to be rapidly incorporated in epilithon. 3. Epilithon N content was dependent upon the grazer species present, with the crayfish treatment having a significantly higher N content than other treatments (P = 0.001). No grazer species effects on epilithon P content were found. However, both grazer treatments had significantly lower epilithon P content than the no-grazer treatment. 4. Traditionally, studies have focused on how grazer-induced structural changes to epilithon can alter epilithon nutrient dynamics, but this structural mechanism could not solely explain differences in epilithon nutrient contents and ratios in the present study. Our results rather suggest that benthic grazers can alter epilithon nutrient composition and limitation via nutrient excretion. Consequently, macroinvertebrate grazers may serve as ‘nutrient pumps’ that partly regulate the availability of nutrients to algae in stream ecosystems.
Recent developments in microwave ultrasonics

Abstract A brief review of some ultrasonic and magnetoelastic delay lines usable at room temperature. These utilize the propagation of ultrasonic microwaves in quartz and magnetoelastic microwaves in yttrium iron garnet. Ultrasonic propagation losses at room temperature are studied and a two-port magnetoelastic delay line is described.
Preparation and Some Basic Properties of Cell-Free Cellulolytic Extracts of Rumen Fluid,

Summary A method was developed by which cell-free cellulolytically active extracts were obtained from rumen fluid. The procedure consisted of agitating rumen fluid in a Waring blendor, followed by high-speed centrifugation to remove bacterial cells and feed particles. Rumen fluid of pH 6.0 yielded the strongest cellulolytically active extracts. Extracts obtained by this method were active on carboxymethylcellulose (CMC 70-L, a soluble cellulose) and exhibited some activity on Whatman cellulose powder (an insoluble cellulose). The optimum pH for the activity of the extracts was 5.5–6.0. Erlenmeyer flasks as incubation vessels facilitated greater cellulose hydrolysis than did test tubes. Two grams of CMC as substrate appeared to be optimum when incubated in 250-ml. flasks containing 10 ml. of extract and 10 ml. of phosphate-citrate buffer. Rates of reaction trials showed maximum rates of hydrolysis immediately after adding the substrate, with little activity after the 16th hr. of incubation. Fermenting rumen fluid with cellulose substrate before making the extraction decreased the activity of the extract. Reducing sugar accumulated in flasks to which no bacterial inhibitor had been added, provided sterile conditions were maintained. The addition of either glucose or glucose and cellobiose did not decrease the rate of CMC hydrolysis. However, paper chromatograms showed that a sugar corresponding to cellobiose was produced in the flasks to which only glucose had been added.
Ancient Israel on Political Leadership: Between the Book Ends

Looking to the US presidential election of 2008, this paper considers models of leadership as they are rendered in the Books of I and II Kings in the Hebrew Bible. That corpus of historical memory is informed by the theo-political traditions of covenant in the book of Deuteronomy. At the beginning of the corpus, Solomon is presented as a leader committed to the pursuit of self-aggrandizement on the basis of political autonomy that need account to none. At the end of the corpus Josiah is presented as a king who practiced public power congruent with the neighborly requirements of Torah. The issue raised by this critical tradition concerns autonomy and moral accountability. There is, of course, no direct transfer of this tradition to US politics. But the testimony of the text lingers, ever critical, even until our time and place, a testimony about limit, connectedness, and consequences.
Isolation and HPLC of N-ε-lithocholyl lysine as its fluorescamine and dimethylaminoazobenzene isothiocyanate derivatives

Abstract N-e-lithocholyl lysine (NELL) is a component of tissue-bound lithocholic acid (TBL). The isolation of NELL from native protein sources was simulated by hydrolysis of lithocholyl-bovine serum albumin (BSA) (synthesized by coupling lithocholyl-N-hydroxysuccinimide to fatty acid-free BSA) by digestion with a mixture of 6N HCl-propionic acid at 70 C for 3 h under partial vacuum. NELL was isolated on a reversed phase Sep-Pak C18 column and converted to either a fluorophor with fluorescamine or to a chromophor with dimethylaminoazobenzene isothiocyanate for subsequent HPLC using appropriate fluorescence or UV/visible absorption detectors. The procedure described here is quantitative, highly sensitive, and not dependent upon the use of Clostridial cholanoylamino acid hydrolase, the activity of which is sometimes blocked by steric hindrance on the substrate. Using this procedure we have demonstrated the presence of TBL in native histomes.
Optical microscope for three-dimensional surface displacement and shape measurements at the microscale.

We report a novel optical microscope for full-field, noncontact measurements of three-dimensional (3D) surface deformation and topography at the microscale. The microscope system is based on a seamless integration of the diffraction-assisted image correlation (DAIC) method with fluorescent microscopy. We experimentally demonstrate the microscope’s capability for 3D measurements with submicrometer spatial resolution and subpixel measurement accuracy.
Electrostatic interactions during activation of coagulation factor IX via the tissue factor pathway: effect of univalent salts.

Abstract Interaction between the Gla-domain of coagulation proteins and negatively charged phospholipid membranes is essential for blood coagulation reactions. The interaction is calcium-dependent and mediated both by electrostatic and hydrophobic forces. This report focuses on the electrostatic component of factor IX activation via the extrinsic pathway. Effective charges during the reaction are measured by ionic titration of activity, according to the Debye–Huckel and Gouy–Chapman models. Rates of activation decrease with ionic strength independently of the type of monovalent salt used to control ionic strength. Moreover, the effect of ionic strength decreases at concentrations of charged phospholipid approaching saturation levels, indicating that membrane charges participate directly in the ionic interaction measured. The effective charge on calcium-bound factor IX during activation on phospholipid membranes is 0.95±0.1. Possible sites mediating contacts between the Gla-domain and membranes are selected by geometrical criteria in several metal-bound Gla-domain structures. A pocket with a solvent opening-pore of area 24–38 A 2 is found in the Gla-domain of factors IX, VII, and prothrombin. The pocket contains atoms with negative partial charges, including carboxylate oxygens from Gla residues, and has a volume of 57–114 A 3 , sufficient to accommodate additional calcium atoms. These studies demonstrate that electrostatic forces modify the activity coefficient of factor IX during functional interactions and suggest a conserved pocket motif as the contact site between the calcium-bound Gla-domain and charged membranes.
Fe-S cluster biogenesis in Gram-positive bacteria: SufU is a zinc-dependent sulfur transfer protein.

The biosynthesis of Fe-S clusters in Bacillus subtilis and other Gram-positive bacteria is catalyzed by the SufCDSUB system. The first step in this pathway involves the sulfur mobilization from the free amino acid cysteine to a sulfur acceptor protein SufU via a PLP-dependent cysteine desulfurase SufS. In this reaction scheme, the formation of an enzyme S-covalent intermediate is followed by the binding of SufU. This event leads to the second half of the reaction where a deprotonated thiol of SufU promotes the nucleophilic attack onto the persulfide intermediate of SufS. Kinetic analysis combined with spectroscopic methods identified that the presence of a zinc atom tightly bound to SufU (Ka = 1017 M–1) is crucial for its structural and catalytic competency. Fe-S cluster assembly experiments showed that despite the high degree of sequence and structural similarity to the ortholog enzyme IscU, the B. subtilis SufU does not act as a standard Fe-S cluster scaffold protein. The involvement of SufU as a dedica...
Generalized matching theorems for closed coverings of convex sets

In this paper we use fixed point and coincidence theorems due to Park [8] to give matching theorems concerning closed coverings of nonempty convex sets in a real topological vector space. Our new results extend previously given ones due to Ky Fan [2], [3], Shih [10], Shih and Tan [11], and Park [7].
Cardiac transplantation: drug regimens for the 21st century

Abstract Survival with congestive heart failure has improved significantly over the last 20 years. However, many patients continue to progress to end-stage disease and suffer unacceptable morbidity and mortality. In the current era, survival after cardiac transplantation approaches 88% to 90% by 1 year at most centers, with more than 50% of patients surviving more than 10 years. Thus, for end-stage patients who are acceptable candidates, cardiac transplantation remains the treatment of choice. The majority of the early (
How far will you go?: using need for closure and information scent to model search stopping behavior

Online searching plays a central role in daily life. During online searching, people first decide which queries to submit to an information retrieval system, after that they decide which links to click on, and based on the quality of search result content, they further determine whether to stop viewing the current returned result set or to refine the query. At some point a person decides to terminate searching. For tasks that require a single answer such as a navigation task, it is relatively clear when a person decides to stop searching -- he or she has either found, or not found, an answer to his or her question. However, for tasks that have no obvious end-point, it is unclear when and why people decide to stop searching and more importantly, it is unclear how to model such behavior. The research question of deciding when information is enough to complete one's task is mostly investigated under the term "search stopping behavior" [3], even though no formal definition has been given in the literature.
Thresholds for synaptic activation of transcription factors in hippocampus: correlation with long-term enhancement

Recent studies suggest a role for rapid induction of transcription factors in stimulus-induced neuronal plasticity in the mammalian brain. Synaptic activation of transcription factors has been analyzed in the hippocampus using the long-term potentiation or enhancement (LTP/LTE) paradigm. Using this approach, several studies have identified transcription factors that are induced in hippocampal granule cells by NMDA receptor-dependent mechanisms; however, the link between long-term plasticity and activation of these genes has been called into question by reports suggesting that the thresholds for LTE and gene activation differ. To address this issue, we have used a chronic in vivo recording technique to monitor mRNA responses of several transcription factor genes to two different patterns of LTE-inducing electrical stimulation of entorhinal cortical afferents to hippocampus. One pattern consisted of 10 repetitions of a 20 or 25 msec train of pulses at 400 Hz (80 or 100 pulses total). This "10-train" pattern has been used in previous studies of LTE and produces robust synaptic enhancement lasting at least 3 d (Barnes, 1979). The other stimulation pattern consisted of 50 repetitions of a 20 msec train delivered at 400 Hz (400 pulses total), which is similar to parameters used in other studies reporting induction of c-fos in association with LTE (Dragunow et al., 1989; Jeffery et al., 1990; Abraham et al., 1992). Our results indicate that expression of zif268, monitored by in situ hybridization and immunostaining, is strongly induced by the 10-train stimulus pattern to levels similar to those induced by seizure activity. JunB mRNA levels are also modestly increased by the 10-train stimulus pattern; however, increases in JunB immunostaining were not detected. Neither c-fos nor c-jun mRNA were detectably induced by this stimulus. In contrast, the 50-train stimulus pattern resulted in a robust induction of c-fos and c-jun mRNA, in addition to zif268 and junB. Transcription factor responses to either stimulus pattern were blocked by the noncompetitive NMDA receptor antagonist MK-801. Identical transcription factor responses were observed in adult (6-12-month-old) and aged (23-26-month-old) rats, suggesting that synaptic mechanisms involved in these responses are preserved in aged animals. Analysis of LTE following either the 10- or 50-train stimulus patterns revealed identical magnitudes of initial induction and decay kinetics (approximately 3 d) and indicates that the 10-train stimulus pattern is sufficient to produce maximal synaptic enhancement.(ABSTRACT TRUNCATED AT 400 WORDS)
Comparison of differences in the hemodynamic response to passive postural stress in healthy subjects >70 years and <30 years of age

To test the hypothesis that age-related increases in arterial pressure alter the cardiovascular response to physiologic stress, 9 healthy elderly volunteers (74 +/- 2 years) and 7 young subjects (27 +/- 3 years) were subjected to a standard 60 degrees upright tilt. Cardiac volumes were measured with patients in the supine position and 5 minutes after they assumed an upright posture using radionuclide ventriculography, while heart rate, blood pressure and forearm cutaneous flow were recorded continuously and simultaneously. Only the expected age-related increase in mean arterial pressure (young subjects, 79 +/- 1 mm Hg; elderly subjects, 99 +/- 3 mm Hg; p less than 0.001) distinguished the 2 groups at baseline. However, during upright tilt, elderly subjects had significant decreases in stroke volume (supine [108 +/- 9 ml] vs upright [78 +/- 9 ml]; p less than 0.01) and cardiac index (supine [3.4 +/- 0.2 liters/min/m2] vs upright [2.8 +/- 0.2 liters/min/m2]; p less than 0.05) because of an inability to reduce end-systolic volume (supine, 44 +/- 6 ml; upright, 51 +/- 7 ml); however, mean arterial pressure was maintained through an increase in peripheral resistance. In contrast, the young relied solely on cardiac adaptations to postural stress by decreasing end-systolic volume (supine, 62 +/- 5 ml; upright, 39 +/- 5 ml; p less than 0.01) and increasing heart rate (57 +/- 2 min-1 to 71 +/- 3 min-1, p less than 0.01), whereby cardiac output and mean arterial pressure were maintained during tilt.(ABSTRACT TRUNCATED AT 250 WORDS)
The Grammatical Metaphor: A Survey of Its Use in the Middle Ages

The history of the grammatical metaphor in the West begins in ancient Greece, with the naming of the rules that govern human speech, and continues up to the present day.* The Stoic philosophers produced fantastic psychological and metaphysical justifications of their word "case" and its subdivisions "upright" and "oblique."' Lucillius (first century A.D.) wrote an epigram in which grammatical terms are given a sexual interpretation.2 Medieval poets, noting the literal meanings of such terms as casus and declinatio both signifying "fall" drew elaborate comparisons between grammar and the story of Adam and Eve: original sin is referred to as "the first declension," and Adam and Eve are "oblique" nouns that fell away or "declined" from God.3 In 1414 the duke of Exeter wrote to Henry IV that "Scotland is like a noun adjective that cannot stand without a substantive," and again in 1658 the Scots were referred to contemptuously as "those northern adjectives, not able to subsist without England."4 In 1783 an anonymous writer in Gentleman's Magazine asked, "Can any of you all impart a rule to conjugate the heart: To shew its present, perfect, future. Its active, passive, and its neuter?"5 More recently, Buckminster Fuller has confided the following piece of insight on the Almighty:
A sparse approximate inverse to the IML matrices allows solution in 5 iterations

A sparse approximate inverse to the impedance matrix localization (IML) method is described which allows solution in five iterations. Numerical results show how well the method discussed works. >
Real-time cooperative interaction between structured-light and reflectance ranging for robot guidance

When applied to rapidly moving objects with complex trajectories, the information-rate limitation imposed by video-camera frame rates impairs the effectiveness of structured-light techniques in real-time robot servoing. To improve the performance of such systems, the use of fast infra-red proximity detectors to augment visual guidance in the final phase of target acquisition was explored. It was found that this approach was limited by the necessity of employing a different range/intensity calibration curve for the proximity detectors for every object and for every angle of approach to complex objects. Consideration of the physics of the detector process suggested that a single log-linear parametric family could describe all such calibration curves, and this was confirmed by experiment. From this result, a technique was devised for cooperative interaction between modalities, in which the vision sense provided on-the-fly determination of calibration parameters for the proximity detectors, for every approach to a target, before passing control of the system to the other modality. This technique provided a three hundred percent increase in useful manipulator velocity, and improved performance during the transition of control from one modality to the other.