cssi/SciSciGPT-SciSciNet huggingface dataset:
What do we know about knowledge utilization

Utilization has gained attention in recent years, but not all utilization is good and not all nonutilization is bad. Ethical issues, organizational arrangements, and roles and skills of the researcher must be considered if the government is to more widely apply research findings for public good.
WE‐C‐T‐617‐01: A First Step Toward a New National Standard for Direct Calibrations in Clinical High Energy Photon Beams

Purpose: Clinical reference dosimetry for high‐energy photon and electron beams is based on ion‐chamber calibrations in a Co‐60 beam for absorbed dose to water, as prescribed in the TG‐51 protocol. A complex formalism is required when converting the calibration to the beam quality of end users. Direct calibrations in clinical high‐energy x‐ray beams will eliminate the complexity and associated uncertainties, resulting in greater accuracy and measurement simplicity. Method and Materials: The current primary standard for absorbed dose is transferred through ionization chambermeasurements in a Co‐60 beam and is ultimately traceable to the first‐generation water calorimeter developed at NIST by Domen. We are evaluating a new calorimeter with modern data acquisition in a Clinac 2100C photon beam at 6 MV and 18 MV. Results: To address the convection/conduction problems inherent to water calorimetry, we have devised a novel data‐collection scheme with multiple cycles of radiation‐induced temperature increase as a function of time; this has greatly improved the efficiency of measurements, thereby achieving greater precision. The temperature rise can be extracted by three approaches that yield consistent results; these will be described in detail in the presentation. The absorbed dose determined at 18 MV and 6 MV using the water calorimeter at selected depth along the beam axis are compared to the depth‐dose curves measured with a calibrated ion chamber following the TG‐51 protocol. In addition, the dependence of bridge‐excitation voltage at the higher dose rate (4 Gy/min) behaves differently from that at a lower rate (1 Gy/min) in a Co‐60 beam; this has been investigated in order to assess the influence of the thermistor power on measured results. Conclusion: We have obtained preliminary results and are moving toward a new national standard for direct calibrations in clinical beams.
An African Perspective on Contemporary Terrorism

Mahmood Mamdani suggests that we turn the cultural theory of politics on its head. He places cultural debates in their historical and political contexts and in so doing claims that terrorism is not a cultural residue in modern politics but a modern construction.
Italy @ 150: The Discourse of the Nation at the Sesquicentennial (1861–2011)

Italian Culture devotes the first volume of its thirtieth issue to a reflection on the discourse of the nation prompted by the sesquicentennial anniversary of Italian unification on March 17 1861, ...
Resolution enhancement using an approximate-inverse Savitzky-Golay smooth

Abstract Any convolution operation, such as the Savitzky-Golay smooth, can be represented as the matrix multiplication of a convolute matrix and a digitized spectrum. The convolute matrix is a band diagonal matrix where the convolute occupies each row, centered on the main diagonal. This convolute matrix can be inverted to provide an inverse convolution operator. In general, these inverse matrices induce large cyclic errors in the data. However, a simple, robust convolute can be extracted from an adjusted inverse matrix. This convolute is not the exact inverse but an approximation. The approximate-inverse Savitzky-Golay convolute provides the inverse of smoothing (i.e. resolution enhancement). This approximate inverse of a smoothing convolute works well, with a significant increase of resolution and minimal decrease in the signal-to-noise ratio of a test NIR spectrum. This resolution enhancement technique, when applied to a set of sample spectra, can improve a multiple-linear-regression model. The derivation of the inverse convolute is shown and the results of its use are discussed.
Histologic markers of mammographic breast density: core-needle biopsy tissue from healthy volunteers.

CTRC-AACR San Antonio Breast Cancer Symposium: 2008 Abstracts Abstract #4037 Background: Mammographic breast density is a strong and consistent risk factor for breast cancer. Women with dense tissue in over 60 to 75% of the breast are at 4 to 6 times greater risk than women with little or no density. However, the biology of breast density is not well understood and studies at the tissue level are limited. We present the first report of a tissue-based study of breast density, sampling mammographically dense and non-dense areas of the breast of healthy women with the goal of examining histologic correlates. Materials and Methods: Healthy women volunteers aged 40 to 85 years, with no breast symptoms, normal screening mammogram within 6 months, and no personal history of breast cancer were considered eligible. Women with breast-related symptoms, those on endocrine therapy, or with bleeding tendencies were excluded from participation. Sixty consecutive eligible women were enrolled in the study- results are based on the first 34 participants. Eligible women underwent an ultrasound-guided, core-needle breast biopsy of mammographically dense and non-dense areas of the breast, performed by a single experienced radiologist. Quantitative assessment of breast tissue from dense and non-dense areas was performed for epithelium, stroma, and fat. In addition, we assessed the difference in the extent of lobular involution (complete, partial and none) between dense and non-dense areas. We used means and SD to describe distributions in each tissue type. Signed rank test was used to assess within woman differences between dense and non-dense tissue. Results: The mean age of the participants was 50.1 years (range 40 to 79 years). The histological findings are outlined below. ![][1] Dense tissue is comprised of increased stroma and epithelium and decreased fat, consistent with prior reports on breast density. The finding of 'no involution' was greater in dense tissue compared to non-dense tissue (24% versus 8.8%); non-dense tissue had greater proportion of complete involution compared to dense tissue (82.5% versus 35.2%). Discussion: This report is the first to quantify histology in tissue sampled from dense and non-dense regions of the healthy breast. We find a dramatic difference in tissue composition between dense and non-dense tissue in the breast. Future studies using this tissue to assess molecular markers will further help to characterize pathways through which density may increase breast cancer risk. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4037. [1]: /embed/graphic-1.gif
Frontal and sagittal electrocardiograms of normal and hypertensive subjects during an experimentally produced phase of lowered blood pressure.

Reduction of the blood pressure in normal and hypertensive subjects by intravenous pyrogen caused the electrocardiograms to assume a more abnormal configuration as judged by present criteria of electrocardiographic normality. A temporary reduction of the blood pressure by the intravenous administration of tetraethylammonium chloride caused only minor and variable modifications of the electrocardiogram. The results of the experiments as done do not support the concept of strain as applied to certain electrocardiographic abnormalities which occur in the course of hypertension.
An electron microscope study of differentiation and growth in oocytes of Ophioderma panamensis.

Electron microscope studies on oocytes of the ophiuroid Ophioderma panamensis indicate the numerous nucleoli to be active throughout much of oogenesis. The nucleoli appear to “spin out” coarse strands of granules and fibers from their periphery (nucleolonema), and become attached at certain points to the inner layer of the nuclear envelope. The nucleolonema appear to fragment into small granular clusters or granule-filament complexes, both of which are also observed in the cytoplasm. During the period of nucleolar activity, mitochondria illustrate a special relationship to the nuclear surface, being preferentially aligned adjacent to the outer layer of the nuclear envelope. Proteid yolk granules first become apparent within certain of the Golgi cisternae. The origin of cortical granules also appears to be associated with the Golgi complexes. During oocyte differentiation an extensive membrane system of vesicles and lamellae, part rough- and part smooth-surfaced, forms in the peripheral portion of the ooplasm. The morphological variations observed during oocyte growth indicate that this membrane system differentiates into (a) annulate lamellae, (b) endoplasmic reticulum which becomes organized into concentric whorls of membranes (within which lipid droplets appear), and (c) single lamellae of endoplasmic reticulum which partially surround each of the Golgi complexes in the cell. The specific arrangement and association between the Golgi complexes and endoplasmic reticulum strongly suggest that the two organelles play a role in the elaboration of proteid yolk granules and cortical granules.
Phage DNA subunits in the phage precursor pool

In the presence of chloramphenicol, phage precursor nucleic acid (DNA) can be allowed to accumulate to form a large intrabacterial pool, while protein synthesis has been temporarily arrested. Radiophosphorus, 32 P, of high specific activity was introduced at various stages and, by following the sensitivity to the radioactive 32 P decay of the final progeny population obtained after removal of the antibiotic, the origin of DNA phosphorus of individual phage particles which were derived from the DNA pool has been investigated. The experiments showed that radioactive decay inactivated the great majority of progeny phages, and that DNA synthesized at different points in time appeared together in the same phage individuals. The findings suggest either that the phage DNA is composed of subunits which are assembled into the entire viral DNA complement only upon maturation of the phages, or that, if the pool already contains the entire phage DNA complement synthesized in advance of its maturation into protein mem- branes, exchange of homologous subunits of the DNA with each other may occur during their sojourn in the pool.
Cationic Ring-Opening Polymerization of 1,3-Benzoxazines: Mechanistic Study Using Model Compounds

The benzoxazine monomer is used to simplify the study of the benzoxazine initiation mechanism. The HPLC retention time and the 1H NMR spectra of crude products from the benzoxazine reaction are compared with the results from a vast number of pure model compounds, which are synthesized based on the hypothesized mechanisms. Products involved in the process are identified, with species having benzoxazine structures, Mannich base and other components (acetal, nonacetal phenoxy structures, and methylene bridge structure). Initiation mechanisms of benzoxazine, e.g., the oxygen protonation and the nitrogen protonation, are proposed.
The future of Mr. Jefferson's Laboratory (né CEBAF)

Abstract We present one viewpoint plus some general information on the plans for energy upgrades and physics research at the Jefferson Laboratory.
Innate Immunity at the Mucosal Surface: Role of Toll-like Receptor 3 and Toll-like Receptor 9 in Cervical Epithelial Cell Responses to Microbial Pathogens

Toll-like receptors (TLRs) are a family of pattern recognition receptors that recognize distinct molecular patterns shared by a broad range of pathogens, including nucleic acids. TLR9, for example, recognizes unmethylated deoxycytidyl-phosphate-deoxyguanosine (CpG) dinucleotides that are common in bacterial and some viral nucleic acids, whereas TLR3 recognizes double-stranded RNA and TLR7/TLR8 recognize single-stranded RNA, which would be found during viral replication. We were interested in whether TLR3, TLR9, and the related TLR9 family members TLR7/TLR8 might play a role in antiviral immune defense at the mucosal epithelial surface of the lower female reproductive tract. We studied cervical epithelial cells and found that they expressed mRNA for TLR3, TLR9, and TLR7, but had only a weak signal for TLR8. For TLR3 and TLR9, protein expression was confirmed to be intracellular. When epithelial cells were incubated with polyinosine-polycytidylic acid and CpG oligodinucleotides, we observed dose-dependent upregulation of interleukin-8 secretion. However, cells failed to respond to a variety of TLR7/TLR8 ligands. Polyinosine-polycytidylic acid also induced production of interferon-beta and chemokine C-C motif ligand 5, whereas CpG DNA did not. Cell activation by synthetic oligodinucleotides occurred only in response to the B class sequences, and required the presence of human-specific CpG motifs. In addition, responses to CpG oligodinucleotides could be inhibited by chloroquine, demonstrating the requirement for endosomal maturation. These data demonstrate that mucosal epithelial cells express functional TLR3 and TLR9, and suggest that these receptors play a role in regulating the proinflammatory cytokine and antiviral environment of the lower female reproductive tract during infection with viral and bacterial pathogens.
Characterization of the “hygroscopic” properties of active pharmaceutical ingredients

The amount of water vapor taken up by an active pharmaceutical ingredient (API) as a function of relative humidity is routinely evaluated to characterize and monitor its "hygroscopicity" throughout the drug development process. In this minireview we address the necessity of going beyond the measurement of water vapor sorption isotherms to establish the various mechanisms by which solids interact with water and the important role played by the crystalline or amorphous form of the solid. Practical approaches for choosing experimental conditions under which water vapor sorption should be measured, including the pre-treatment of samples and the time allowed to reach an equilibrium state are presented. With the assistance of a flowchart, we provide a basis for the systematic examination of samples to establish the likely mechanisms of sorption and the indicators pointing toward future problems with physical and chemical instabilities. Finally, we present strategies for managing materials that might be susceptible to the detrimental effects of water vapor sorption.
An examination of misclassifications with bank failure prediction models

Abstract Unlike prior work in the area of bank failure prediction, this article focuses on misclassifications: the individual banks that were predicted by a model to fail and yet have not, and those predicted to survive and yet have failed. The concern here is with the profile of these misclassified banks and the causes of their success or failure. Linear and quadratic multiple discriminant analysis models and Cox proportional hazards models are employed. The performance of these models is examined in periods subsequent to that over which they were estimated. The results provide insights for the development and application of early warning models for banks.
Initial evaluation of an IEEE 802.11s-based mobile ad-hoc network for collaborative Unmanned Aerial Vehicles

The purpose of this research was to develop a reconfigurable network architecture for collaborative Unmanned Aerial Vehicles (UAVs) based on a mesh networking standard called IEEE 802.11s. A low-cost, small form-factor, IEEE 802.11a based wireless modem was selected and integrated with the existing Flight Control System developed at Virginia Commonwealth University UAV Laboratory. A self-configurable user-space application was developed that can provide support and functionality to collaborative algorithms. The reconfigurability of the IEEE 802.11s mesh network was validated and evaluated by conducting real-world flights using two UAV nodes and one ground node. The results show that the IEEE 802.11s is a promising solution for collaborative UAV applications.
Optical pulling of airborne absorbing particles and smut spores over a meter-scale distance with negative photophoretic force

We demonstrate optical pulling of single light-absorbing particles and smut spores in air over a meter-scale distance using a single collimated laser beam based on negative photophoretic force. The micron-sized particles are pulled towards the light source at a constant speed of 1–10 cm/s in the optical pulling pipeline while undergoing transverse rotation at 0.2–10 kHz. The pulled particles can be manipulated and precisely positioned on the entrance window with an accuracy of ∼20 μm, and their chemical compositions can be characterized with micro-Raman spectroscopy.
Dynamics of the healing of skin wounds in the horse as compared with the rat

Abstract The dynamics of skin wound healing were studied in three horses with either full thickness skin excision or with subcutaneously implanted polyvinyl alcohol sponges. Granulation tissue and reactive granuloma were harvested from three anatomical sites and were analyzed by morphological and biochemical methods at three time intervals. PVA sponges were also implanted in rats and studied by similar methods. No effect of wound or implant location on morphology or density of the sample tissue was found. In the horse, neutrophil infiltration was found in the tissue of wounds less than one day old. This tissue actively synthesized collagen and showed high activity of collagenase. The activity of prolyl hydroxylase (PH), however, was low. At later time sampling period (3, 7, 14 days), both granulation and granuloma tissue showed increasing PH activity, high activity of collagenase, and decreasing rate of collagen synthesis. Collagen content also increased with time. The reactive granuloma tissue found in rats showed less connective tissue reactivity than in the horse as seen by the dynamics of the morphological and biochemical changes of the tissue. We conclude that the healing in the horse is rather prompt and excessive and may tend toward abnormal repair reactions.
Evaluation of Sampling Methods for Lady Beetles (Coleoptera: Coccinellidae) in Grain Sorghum

Four sampling techniques (visual counts on 50 plant samples, sweepnet, drop cloth, and pitfall traps) were evaluated over a 3-yr period to determine the most efficient methods in terms of time, effort, and precision for estimating coccinellid population densities in grain sorghum. Correlations were made among the four techniques, using visual counts as the absolute method, and estimates were made of the relative sampling variation (precision) and relative net precision (efficiency) for each technique. Visual counts were the most efficient sampling method when high precision is desired, regardless of time consh aints. When time is a constraint, the drop cloth method is most precise and efficient, followed by sweepnet sampling.
Primary Familial Amyloidosis of the Cornea

A case of primary familial amyloidosis of the cornea in a 13-year-old boy was confirmed by histopathologic examination of material obtained by penetrating keratoplasty. Elevated subepithelial nodules of amyloid were present centrally. Extensive nonelevated subepithelial amyloid deposition was present in areas where either clinically gray, nonelevated subepithelial opacities or apparently normal cornea was present. Nonelevated subepithelial corneal deposits clinically similar to amyloid deposits in the proband were present in two siblings. The genetic pattern of the corneal amyloid deposits in this family appears to be autosomal recessive. Cataracts were present in two of the three affected members. Aspirated lens material from two of the affected members did not contain amyloid.
The phase transition of the directed polymer on disordered hierarchical lattices

The directed polymer on disordered hierarchical lattices is studied using an exact renormalization scheme. The phase transition is studied and a hyperscaling relation is derived. The fixed distributions of the renormalized energies are obtained numerically. The specific heat and associated exponents are computed from the fixed distributions.
Design for product retirement and material life-cycle

Abstract Life-cycle design seeks to maximize the life-cycle value of a product at the early stages of design, while minimizing cost and environmental impact. This paper focuses on product retirement and advanced planning for material recycling. Design for product retirement (DFPR) applies to retirement strategies, i.e. designers' intent for product disassembly and reprocessing of subassemblies and components. The method combines quantitative cost formulae and qualitative guidelines to determine the feasibility and cost benefits of a candidate retirement plan. Material life-cycle analysis (MLCA) addresses essential knowledge used by DFPR, i.e. assessment of residual value of a material when recycled under a certain scenario. For plastic components, we have been developing a standard for evaluating the residual mechanical strength of materials recycled from various product histories and assessing necessary processes to remedy the degradation. This standard, combined with other material compatibility information and disassembly knowledge, makes DFPR a viable tool for life-cycle design. The paper illustrates our prototype computer tool for DFPR using an example from the computer industry.
Analysis of the Time-Dependent Chemical Evolution of Titan Haze Tholin

Haze particles exert a significant influence over the thermodynamics and radiation absorption properties of the Titan haze, as well as its complex organic chemistry. Characterization of both the molecular and the submicrometer components of the haze is therefore vital for understanding the global properties of Titan. We have carried out a Titan tholin synthesis experiment and measured the time variation of the infrared spectrum of the product as a thin film developed. Also, to examine the possibility of oxygen contamination, we compared the infrared spectrum of the tholin film with that of a tholin film exposed to dry air and laboratory air. The objective of this study is to understand the chemical processes related to how simple organic molecules are processed into more complex haze particles. The progressive development of features characteristic of amines, aromatic and aliphatic hydrocarbons, and nitriles in the experimental mixture is clear. Of particular interest is the formation of aromatic rings after only a few seconds of glow discharge, indicating that these compounds appear to be intermediates between simple haze molecules and microphysical aerosols. The early dominance of aromatic ring structures is accompanied during the later stages of the experiment by the appearance of nitrile and amine compounds. This time-dependent succession of chemical structures provides vital clues to the possible chemical formation pathways of Titan haze aerosols.
What do Pre-Service Teachers See as Their Roles in Promoting Positive Social Environments? “I see Myself as a Facilitator of Acceptance”

Teacher educators describe a developmental process they use for preparing pre-service teachers to support preschool-age children with and without disabilities in becoming socially competent. Social competence is crucial in developing the “whole” child and may actually foster other areas of development. Using qualitative data gathered from multiple classes over several years, the authors explain ways they guide future teachers in learning how to provide positive social environments. They describe their observations of changes in students’ beliefs about their roles and responsibilities, which appear to be influenced by the guided experiences they have provided. Activities implemented in early childhood and early childhood special education courses are shared, as well as student work samples that illustrate developing awareness and understanding.
Carcinoma of the superior pulmonary sulcus.

Abstract From January, 1971, to January, 1977, 26 patients underwent surgical resection of a carcinoma of the superior pulmonary sulcus. They ranged from 33 to 77 years old. All but 1 had symptoms characteristic of Pancoast's syndrome. The site of involvement was the right superior sulcus in 17 patients and the left superior sulcus in 9. All patients were treated by lobectomy and extended en bloc resection. Twenty-five patients survived operation. There was 1 early postoperative death. Twenty-two patients had been followed for at least 3 years, and 8 had survived for 5 years, at the time of writing. Nine patients died of recurrent disease from five months to 3 years after operation. Important considerations in postoperative care include routine use of continuous positive airway pressure and intermittent mandatory ventilation.
Two-dimensional normal zone propagation in BSCCO-2223 pancake coils☆

Abstract We present the results of an experimental and analytical study of two-dimensional normal zone propagation in pancake test coils, wound with silver-sheathed BSCCO-2223 tapes. Two test coils were studied in detail, one having three and the other eight layers. Each test coil was housed in an adiabatic environment whose temperature (20–70 K) was controlled and maintained by a two-stage G-M cryocooler and placed in a background field (0–6 T) generated by a Bitter magnet. With a test coil carrying a transport current (0–200 A), a local heat disturbance was applied by a heater attached to the outermost layer of the coil. The resulting electrical and thermal responses of the coil were recorded with voltage taps and thermometers attached to the coil. A normal zone propagation code was developed to accurately simulate the voltage and temperature responses of each coil for both quenching and recovering events. The code solves the nonlinear transient heat diffusion equation in two-dimensional cylindrical coordinates with a finite difference method. As an application of this code, a two-coil system, with each coil comprised of one double pancake wound with silversheathed BSCCO tape, was studied for its quench behaviour as one of the coils was driven normal locally. The simulation results indicate that the value of a shunt resistor connected across the terminals of each coil has a profound effect on the level of hotspot temperature reached in the quench initiation spot.
Collaboration as the Norm in Reference Work

The stereotype of the reference transaction is more or less unchanged since Samuel Swett Green’s day, as involving precisely one librarian and one user. There are many common situations in which the reference transaction is not a one-to-one interaction, and this article will explore those situations. Additionally, this article argues that as network technology is increasingly utilized in reference work, situations in which the reference transaction is not a one-to-one interaction are becoming more common. Indeed, this article argues that as network technology is increasingly utilized in reference work, reference work will become fundamentally a collaborative effort, to the benefit of both individual reference services and reference work in general.
Charge equilibration in deep inelastic reactions

Abstract We compare two mechanisms for charge equilibration in deep inelastic collisions: (1) diffusion resulting from different initial charge densities, and (2) dynamics based on the liquid drop potential. We find that equilibration occurs rapidly in both cases.
Deformation and fracture behavior of laser processed dense and porous Ti6Al4V alloy under static and dynamic loading

Abstract Deformation and fracture behavior of laser processed dense and porous Ti6Al4V alloy under uniaxial static and dynamic compression loadings were experimentally investigated in this study. Samples with 0%, 10% and 20% porosities were fabricated using a continuous wave Nd–YAG laser in a controlled environment. The dynamic tests were performed at the strain rates of 1 × 103, 4 × 103 and 8 × 103/s using the split Hopkinson pressure bar (SHPB) test system and the static tests were done at the strain rate of 1 × 10−3/s. In addition, SEM and EBSD analyses were also carried out to study the failure mechanisms and texture development due to solidification and deformation. Both deformation and fracture exhibited appreciable rate sensitivity. For the former, the material strength increased, and for the latter, the failure strains decreased with the increased strain rates. The 20% porous Ti6Al4V showed lower strength, but higher ductility compared to the 10% material, but the 10% porous material had both less strength and ductility than the dense (0% porosity) material and the ductility of 20% porous material was only comparable to that of the dense material, i.e., did not exhibit appreciable increase of ductility. The texture analysis indicated that all the samples had reasonably consistent textures due to solidification. Hence the texture effect is essentially negligible and the observed material behavior is mainly a manifestation of the induced porosity. Both the macroscopic experiments and the microstructure analysis suggest that the formation of adiabatic shear band (ASB) could likely be the major failure mechanism for Ti6Al4V and the pores likely be the sites for nucleating ASB and subsequent catastrophic failure. For initially dense Ti6Al4V, the failure and the corresponding failure strain seem to depend on the duration of the incubation period for developing a nucleation site.
An architecture for sensor fusion in intelligent process monitoring

Abstract This paper suggests an architecture for sensor fusion in intelligent process monitoring. The paper reviews the need for sensor fusion in manufacturing process control, describes the architecture and provides an example of its implementation in the laboratory.
Temporal variation in the Vt-Ti relationship in humans☆

Abstract The variation with time of the relationship between tidal volume (V t ) and inspiratory duration (T i ) was assessed by analysis of 34 breathing sequences, nominally of 300 breath duration, during eupnea and hypercapnic hypernea in 6 human subjects. Two approaches were used: (1) each sequence was delivered into consecutive 50-breath and standard regression techniques used to characterize V t as a function of T i ; and (2) a piecewise linear regression technique was applied to cluster consecutive breaths into regression regimes. Analysis of covariance was used with the results of both approaches to determine the likelihood that a single regression line was adequate to describe the entire data set. Similar results obtained regardless of the approach used. In only 4 of the 34 experiments would the hypothesis of regression slope homogeneity be accepted (p > 0.05) using the clustering approach; in 27 experiments, it was indicated that the regression slope estimates of V t and T i should not be considered homogeneous. Changes in the V t -T i slope were not correlated with changes in mean levels of V t , T i , minute ventilation (V, mean inspiratory flow (V t /T i ), nor alveolar PCO2 (P a CO2). Thus it is apparent that the V t -T i relation cannot be considered temporally invariant, but changes with time over periods ranging from less than 20 to more than 100 breaths.
An Introduction to Genetic Algorithms

From the Publisher: "This is the best general book on Genetic Algorithms written to date. It covers background, history, and motivation; it selects important, informative examples of applications and discusses the use of Genetic Algorithms in scientific models; and it gives a good account of the status of the theory of Genetic Algorithms. Best of all the book presents its material in clear, straightforward, felicitous prose, accessible to anyone with a college-level scientific background. If you want a broad, solid understanding of Genetic Algorithms -- where they came from, what's being done with them, and where they are going -- this is the book. -- John H. Holland, Professor, Computer Science and Engineering, and Professor of Psychology, The University of Michigan; External Professor, the Santa Fe Institute. Genetic algorithms have been used in science and engineering as adaptive algorithms for solving practical problems and as computational models of natural evolutionary systems. This brief, accessible introduction describes some of the most interesting research in the field and also enables readers to implement and experiment with genetic algorithms on their own. It focuses in depth on a small set of important and interesting topics -- particularly in machine learning, scientific modeling, and artificial life -- and reviews a broad span of research, including the work of Mitchell and her colleagues. The descriptions of applications and modeling projects stretch beyond the strict boundaries of computer science to include dynamical systems theory, game theory, molecular biology, ecology, evolutionary biology, and population genetics, underscoring the exciting "general purpose" nature of genetic algorithms as search methods that can be employed across disciplines. An Introduction to Genetic Algorithms is accessible to students and researchers in any scientific discipline. It includes many thought and computer exercises that build on and reinforce the reader's understanding of the text. The first chapter introduces genetic algorithms and their terminology and describes two provocative applications in detail. The second and third chapters look at the use of genetic algorithms in machine learning (computer programs, data analysis and prediction, neural networks) and in scientific models (interactions among learning, evolution, and culture; sexual selection; ecosystems; evolutionary activity). Several approaches to the theory of genetic algorithms are discussed in depth in the fourth chapter. The fifth chapter takes up implementation, and the last chapter poses some currently unanswered questions and surveys prospects for the future of evolutionary computation.
Mechanisms of Site-Specific Recombination*

AbstractIntegration, excision, and inversion of defined DNA segments commonly occur through site-specific recombination, a process of DNA breakage and reunion that requires no DNA synthesis or high-energy cofactor. Virtually all identified site-specific recombinases fall into one of just two families, the tyrosine recombinases and the serine recombinases, named after the amino acid residue that forms a covalent protein-DNA linkage in the reaction intermediate. Their recombination mechanisms are distinctly different. Tyrosine recombinases break and rejoin single strands in pairs to form a Holliday junction intermediate. By contrast, serine recombinases cut all strands in advance of strand exchange and religation. Many natural systems of site-specific recombination impose sophisticated regulatory mechanisms on the basic recombinational process to favor one particular outcome of recombination over another (for example, excision over inversion or deletion). Details of the site-specific recombination processes...
GTP-dependent heteropolymer formation and bundling of chloroplast FtsZ1 and FtsZ2.

Bacteria and chloroplasts require the ring-forming cytoskeletal protein FtsZ for division. Although bacteria accomplish division with a single FtsZ, plant chloroplasts require two FtsZ types for division, FtsZ1 and FtsZ2. These proteins colocalize to a mid-plastid Z ring, but their biochemical relationship is poorly understood. We investigated the in vitro behavior of recombinant FtsZ1 and FtsZ2 separately and together. Both proteins bind and hydrolyze GTP, although GTPase activities are low compared with the activity of Escherichia coli FtsZ. Each protein undergoes GTP-dependent assembly into thin protofilaments in the presence of calcium as a stabilizing agent, similar to bacterial FtsZ. In contrast, when mixed without calcium, FtsZ1 and FtsZ2 exhibit slightly elevated GTPase activity and coassembly into extensively bundled protofilaments. Coassembly is enhanced by FtsZ1, suggesting that it promotes lateral interactions between protofilaments. Experiments with GTPase-deficient mutants reveal that FtsZ1 and FtsZ2 form heteropolymers. Maximum coassembly occurs in reactions containing equimolar FtsZ1 and FtsZ2, but significant coassembly occurs at other stoichiometries. The FtsZ1:FtsZ2 ratio in coassembled structures mirrors their input ratio, suggesting plasticity in protofilament and/or bundle composition. This behavior contrasts with that of α- and β-tubulin and the bacterial tubulin-like proteins BtubA and BtubB, which coassemble in a strict 1:1 stoichiometry. Our findings raise the possibility that plasticity in FtsZ filament composition and heteropolymerization-induced bundling could have been a driving force for the coevolution of FtsZ1 and FtsZ2 in the green lineage, perhaps arising from an enhanced capacity for the regulation of Z ring composition and activity in vivo.
Excretion of riboflavin by iron deficient plants

Abstract Roots of mild iron deficient plants have frequently been observed to excrete riboflavin. There is some evidence that the riboflavin contributes to iron efficiency. Previous papers of this symposium have described several iron response mechanisms. Another possible iron stress response is that of excretion of riboflavin which has been demonstrated with iron deficiency in many plant species (Frolich and Wallace, 1966; Nagarajah and Ulrich, 1966; Wallace et al., 1968, 1971a,b; and Welkie and Miller, 1960). After a short period of iron deficiency, roots of tobacco, soybeans, sugar beets. Ambrosia, and others excrete riboflavin. Enhanced iron transport in the xylem exudate of tobacco under iron deficiency was associated with riboflavin in the exudate (Wallace, 1971a). The same workers found improved greening of iron deficient tobacco plants after the riboflavin color had disappeared from the nutrient solution (Wallace, 1969). The role of riboflavin has never been fully evaluated even though riboflavin ...
Experimental Investigation of Thermoelastic Deformation in Turbojet-Engine Bearings Under Maintenance Inspection

The present investigation examined the vertical and horizontal thermoelastic changes in the outside diameter of a turbojet-engine roller bearing. Thermal loads were imparted to the bearing by the hands of a bearing technician during a rework operation. A worst-case analysis was examined by assuming a three-minute dwell time and diametrically symmetric thermal loading. Contact temperature was experimentally determined and used in conjunction with a numerical model to simulate thermal propagation throughout the bearing outer ring. Diametric deflection data, obtained using the contact temperature in conjunction with analytic and finite elements, have been shown for comparative purposes. Experimental diametric expansions of the bearing outer ring were determined and compared with the predicted results. Assuming a worst-case scenario, this investigation yielded vertical expansions in the bearing outer ring`s diameter, which would be problematic for some bearings during the rework operation; appropriate corrective action was discussed.
EFFECTS ON CHILDREN OF HAVING LIVED WITH A PARENT WHO HAS AN ANXIETY DISORDER

The purpose of this article is to show that the mental illness of a parent, in this case an anxiety disorder, can have a significant, negative impact on children. A brief history of the concept of anxiety is provided, showing the multifaceted nature of anxiety. The Integrative Model of Anxiety (Akiskal, 1985) is outlined to provide a current definition of anxiety. This article concludes by describing the role that nursing can play in intervening on behalf of children whose parents have an anxiety disorder. Finally, a proposed study is outlined.
Neurosteroid analogues. 14. Alternative ring system scaffolds: GABA modulatory and anesthetic actions of cyclopenta[b]phenanthrenes and cyclopenta[b]anthracenes.

Although the structural features of binding sites for neuroactive steroids on γ-aminobutryic acid type A (GABAA) receptors are still largely unknown, structure–activity studies have established a pharmacophore for potent enhancement of GABAA receptor function by neuroactive steroids. This pharmacophore emphasizes the importance of the position and stereochemistry of hydrogen-bonding groups on the steroid. However, the importance of the steroid ring system in mediating hydrophobic interactions with the GABAA receptor is unclear. We have taken the cyclopenta[b]phenanthrene (tetracyclic compounds with a nonlinear ring system different from that of steroids) and cyclopenta[b]anthracene (tetracyclic molecules with a linear 6–6–6–5 carbocyclic ring system) ring systems and properly substituted them to satisfy the pharmacophore requirements of the critical hydrogen-bond donor and acceptor groups found in neuroactive steroids. We have found these cyclopenta[b]phenanthrene and cyclopenta[b]anthracene analogues to ...
Cooperative Binding of DctD to the dctA Upstream Activation Sequence of Rhizobium meliloti Is Enhanced in a Constitutively Active Truncated Mutant

DctD, a σ54-dependent, two-component regulator, binds to promoter distal (A) and promoter proximal (B) sites in an activation sequence located upstream of the dctA promoter. We report gel filtration and quantitative DNase I footprint experiments supporting a model in which DctD2 binds to these sites cooperatively. The global analysis of upstream activation sequences containing sites A and B, A and B one-half helical turn out of phase, and only B yielded values for the intrinsic and cooperative binding free energies of ΔG0A = −9.5 ± 0.3, ΔG0B = −11.2 ± 0.2, and ΔG0AB = −2.5 ± 0.5. A separate analysis of data from upstream activation sequences containing site A and a point mutant of site B, and site A and mutant site B one-half helical turn out of phase confirmed the estimate of cooperativity, yielding free energy values of ΔG0A = −9.4 ± 0.2, ΔG0B(G→C) = −10.0 ± 0.2, and ΔG0AB(G→C) = −2.2 ± 0.4. We previously showed that removing the two-component receiver domain from DctD, making DctDΔ(1-142), yields a constitutively active truncated protein. Global analysis of binding data for DctDΔ(1-142) showed that this constitutively active mutant has intrinsic binding energies equal to that of the inactive DctD protein, but that it displays significantly higher cooperativity (ΔG0A = −9.4 ± 0.6, ΔG0B = −11.1 ± 0.3, and ΔG0AB = −3.8 ± 0.6.).
Quantitative, three-dimensional analysis of alfalfa egg cells in two genotypes: Implications for biparental plastid inheritance

In alfalfa (Medicago sativa L.), plastids are inherited biparentally. Patterns of plastid transmission vary according to the genotypes involved, but there is a strong bias in favor of male plastid transmission. Previous cytological studies on the male gametophyte of this species have not provided an adequate explanation for the differences in plastid transmission frequencies among genotypes. In the present study, we compared egg cells from genotypes classified as strong or weak plastid transmitters to determine whether plastid transmission strength is correlated with egg cell structure before fertilization. We found that plastids in the mature egg cells of the strong female (genotype 6–4) are significantly larger than in mature eggs of the weak female (genotype CUF-B), and that significantly more plastids are positioned in the apical portion of the mature egg cell of genotype 6–4 than in CUF-B. Immature eggs in the two genotypes show the same pattern as mature eggs with regard to plastid number and polarization. Since only the apical portion of the egg cell/zygote gives rise to the functional embryo, these results indicate that the potential input of female plastids, in terms of plastid size and number, may be an important factor in determining the inheritance patterns of these organelles in alfalfa.
Mechanism of action of a cytotonic enterotoxin produced by Aeromonas hydrophila

In this study, we describe the mechanism of action of a cytotonic enterotoxin produced by two isolates of Aeromonas hydrophila. Isolates SSU and Ah65 are of different origin and both are capable of producing either a cytotoxic enterotoxin or aerolysin. A cytotonic enterotoxin produced by diarrheal isolate SSU, which was purified and characterized in our laboratory, elevated intracellular cAMP and PgE2 levels in cultured Chinese hamster ovary (CHO) cells. Likewise, enterotoxic activity expressed by a cytotonic enterotoxin was detected in the culture filtrate of a fish isolate (Ah65) after cytotoxic activity was neutralized with homologous aerolysin monoclonal antibodies. This cytotonic enterotoxin also elevated intracellular cAMP and PgE2 levels in CHO cells, suggesting a cholera toxin-like mechanism of action for Aeromonas cytotonic enterotoxins.
Polycomb repressive complex 2 regulates normal development of the mouse heart.

Rationale:Epigenetic marks are crucial for organogenesis, but their role in heart development is poorly understood. Polycomb repressive complex 2 (PRC2) trimethylates histone H3 at lysine 27, which...
CRIME SHOW VIEWING BY PREADULTS The Impact on Attitudes Toward Civil Liberties

The research reported here examines the impact of viewing television crime shows on preadults' attitudes toward civil liberties. The data analyzed were the result of a survey of school children in grades six through twelve. Generally, heavy viewers of crime shows were more likely to have anti-civil libertarian attitudes. This relationship survived controls for seven background variables. Crime show viewing had its greatest impact on the attitudes of subgroups that normally are predisposed to support a civil libertarian viewpoint. These groups included children in the higher grades, children from middle class homes, and children whose parents do not place a great deal of stress on conformity. The results indicate that television entertainment may be an important source of political learning.
Release of intracellular Zn 2+ in cultured neurons after brief exposure to low concentrations of exogenous nitric oxide

Several studies have shown intracellular Zn(2+) release and concomitant cell death after prolonged exposure to exogenous NO. In the present study, we investigated whether cortical neurons briefly exposured to exogenous NO would demonstrate similar levels of intracellular Zn(2+) release and subsequent cell death. Cortical neurons were loaded with the Zn(2+) selective fluorophore FluoZin-3 and treated with various concentrations of the NO generator, spermine NONOate. Fluorescence microscopy was used to detect and quantify intracellular Zn(2+) levels. Concomitant EDTA perfusion was used to eliminate potential effects of extracellular Zn(2+). Neurons were perfused with the heavy metal chelator TPEN to selectively eliminate Zn(2+) induced fluorescence changes. A significant increase of intracellular fluorescence was detected during a 5 min perfusion with spermine NONOate. The increase in intracellular Zn(2+) release appeared to peak at 1 microM spermine NONOate (123.8 +/- 28.5%, increase above control n = 20, P < 0.001). Further increases in spermine NONOate levels as high as 1 mM failed to further increase detectable intracellular Zn(2+) levels. The NO scavenger hemoglobin blocked the effects of spermine NONOate and the inactive analog of the spermine NONOate, spermine, was without effect. No evidence of cell death induced by any of the brief treatments with exogenous NO was observed; only prolonged incubation with much larger amounts of exogenous NO resulted in significant cell death. These data suggest that in vivo release of NO may cause elevations of intracellular Zn(2+) in cortical neurons. The possibility that release of intracellular Zn(2+) in response to NO could play a role in intracellular signaling is discussed.
The Expected order of a Random Permutation

Let fin be the expected order of a random permutation, that is, the arithmetic mean of the orders of the elements in the symmetric group Sn. We prove that log/in ~ c\/(n/\ogn) as n -> oo, where