cssi/SciSciGPT-SciSciNet huggingface dataset:
Microstructure-based modeling of the deformation behavior of particle reinforced metal matrix composites

A review is provided of the use of analytical models and two dimensional (2D) and three dimensional (3D) microstructure based FEM models to accurately predict the properties of particle reinforced composite materials. It is shown that analytical models do not account for the microstructural factors that influence the mechanical behavior of the material. 2D models do capture the anisotropy in deformation behavior induced by anisotropy in particle orientation. The experimentally-observed dependence of Young's modulus and tensile strength is confirmed by the 2D microstructure-based numerical model. However, because of the 2D stress state, a realistic comparison to actual experimental values is not possible. A serial sectioning process can be used to reproduce and visualize the 3D microstructure of particle reinforced metal matrix composites. The 3D microstructure-based FEM accurately represents the alignment, aspect ratio, and distribution of the particles. Comparison with single particle and multiparticle models of simple shape (spherical and ellipsoidal) shows that the 3D microstructure-based approach is more accurate in simulating and understanding material behavior.
Excimer and photochemically induced fluorescence of 9-cyanoanthracene crystals

Abstract The polarized emission spectra of melt and vapor grown single crystals of carefully purified 9-cyanoanthracene (9-CNA) are reported. This materials has a quasi one-dimensional structure with molecules stacked along the c-axis. In crystals previously unirradiated at room temperature, the emission is excimer-like with a double peak (550 nm, E⊥c) and (525 nm, E|c) at 2 K, and a single peak at 300 K (588 nm, E, |c). Exposure to UV radiation at room temperature induces fluorescence associated with the production of photodimers. At 2 K this fluorescence is highly structured and coexists with excimer emission. It also extends to higher energies than the origin of the exciton band of the first singlet, supporting a model in which this component of the fluorescence arises from 9-CNA molecules separated from bulk by a matrix of photodimers. The photoproduct thus acts somewhat like a Shpol'skii matrix for these unreacted molecules.
Effect of the Nature of the Counterion on the Properties of Anionic Surfactants. 1. Cmc, Ionization Degree at the Cmc and Aggregation Number of Micelles of Sodium, Cesium, Tetramethylammonium, Tetraethylammonium, Tetrapropylammonium, and Tetrabutylammonium Dodecyl Sulfates

The surfactants cesium, tetramethylammonium, tetraethylammonium, tetrapropylammonium and tetrabutylammonium dodecyl sulfates (CsDS, TMADS, TEADS, TPADS, and TBADS) have been synthesized by ion-exchange. The critical micellization concentration in the absence of added salt (cmc) has been determined at 10, 25, and 40 °C using the electrical conductivity method. The cmc was found to decrease in the sequence CsDS > TMADS > TEADS > TPADS > TBADS. The value of the cmc depends very little on temperature, going through a shallow minimum around 25 °C for most surfactants investigated. The micelle aggregation numbers have been determined using the time-resolved fluorescence quenching method, with the pyrene/dodecylpyridinium chloride as fluorescent probe/quencher pair, at various surfactant concentrations and, in the case of TMADS, in the presence of tetramethylammonium chloride. The micelle ionization degree α0 at the cmc has been determined from the electrical conductivity data and the values of the aggregation n...
Cell-free fetal DNA levels in maternal plasma after elective first-trimester termination of pregnancy

Abstract Objective To determine if first-trimester elective termination of pregnancy affects cell-free fetal DNA (fDNA) levels in maternal plasma. Design Prospective cohort study. Setting Clinical and academic research centers. Patient(s) One hundred thirty-four women who underwent first-trimester elective termination procedures. Intervention(s) None. Main outcome measure(s) Real-time polymerase chain reaction (PCR) amplification and measurement of DYS1 , a Y-chromosome sequence, was used as a marker of fDNA. Result(s) We detected fDNA in pretermination samples from 27 out of 71 patients in the surgical arm, and 29 out of 63 patients in the medical arm. Based on confirmation of male gender in placental tissue, the sensitivity of fDNA detection is 92.6%. We detected fDNA as early as 32 days of gestation, which increased 4.2 genome equivalents/mL/week. In the surgical arm, the mean level of posttermination fDNA, adjusted for the clearance of fDNA in maternal blood, was higher than projected based on an expected increase with gestational age. In the medical arm, six patients had increased fDNA levels up to 11 days following termination. Conclusion(s) We found that fDNA can be reliably quantified in the early first trimester; fDNA elevation that occurs shortly after surgical termination may reflect fetomaternal hemorrhage or destruction of trophoblastic villi. Continued elevation of fDNA for several days may occur following medical termination.
Cyclooxygenase-1 Deficiency in Bone Marrow Cells Increases Early Atherosclerosis in Apolipoprotein E– and Low-Density Lipoprotein Receptor–Null Mice

Background— Cyclooxygenase-1 (COX-1) has been implicated in the pathogenesis of atherothrombosis and is expressed by the major cell types of atherosclerotic lesions. COX-1–mediated platelet thromboxane (TX) production has been proposed to promote both early atherosclerosis and thrombosis. Here, we examined the impact of COX-1 deficiency in bone marrow–derived cells on early atherogenesis in the mouse. Methods and Results— LDL receptor (LDLR)−/− and apolipoprotein E (apoE)−/− recipient mice were lethally irradiated and transplanted with COX-1−/− bone marrow. Mice reconstituted with COX-1−/− marrow had nearly complete (99.7%) loss of platelet TXA2 and significantly suppressed levels of macrophage and urinary TXA2 metabolites. Serum lipid levels and lipoprotein distributions did not differ between recipients reconstituted with COX-1+/+ and COX-1−/− marrow. Surprisingly, the extent of atherosclerotic lesions in both LDLR−/− and apoE−/− mice reconstituted with COX-1−/− marrow was increased significantly compar...
AP-1 and vitamin D receptor (VDR) signaling pathways converge at the rat osteocalcin VDR element: requirement for the internal activating protein-1 site for vitamin D-mediated trans-activation

Responsiveness of genes to steroid hormones is a complex process involving synergistic and/or antagonistic interactions between specific receptors and other nonreceptor transcription factors. Thus, DNA recognition elements for steroid hormone receptors are often located among binding sites for other trans-acting factors. The hormonal form of vitamin D, 1,25-dihydroxyvitamin D3, stimulates transcription of the tissue-specific osteocalcin (OC) gene in osteoblastic cells. The rat OC vitamin D response element contains an internal acitvating protein-1 (AP-1) site. Here, we report for the first time that this AP-1 site is critical for the transcriptional enhancement of rat osteocalcin gene expression mediated by vitamin D. Precise mutations were introduced either in the steroid half-elements or in the internal AP-1 sequences. One mutation within the internal AP-1 site retained vitamin D receptor/retinoid X receptor binding equivalent to that of the wild-type sequence, but resulted in complete loss of vitamin D inducibility of the OC promoter. These results suggest a functional interaction between the hormone receptor and nuclear oncoproteins at the rat OC vitamin D response element. This cooperation of activities may have important consequences in physiological regulation of osteocalcin transcription during osteoblast differentiation and bone tissue development in vivo.
Corrigendum to “Failure of mineralized collagen fibrils: Modeling the role of collagen cross-linking” (J. Biomech. 41 (2008) 1427–1435)

Corrigendum to ‘‘Failure of mineralized collagen fibrils: Modeling the role of collagen cross-linking’’ (J. Biomech. 41 (2008) 1427–1435) Thomas Siegmund a, , Matthew R. Allen , David B. Burr b,c,d a School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA b Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA c Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA d Biomedical Engineering, Indiana University—Purdue University at Indianapolis, Indianapolis, IN 46202, USA
Optical Measurements at the Combustor Exit of the HIFiRE 2 Ground Test Engine

The development of optical techniques capable of measuring in-stream flow properties of air breathing hypersonic engines is a goal of the Aerospace Propulsion Division at AFRL. Of particular interest are techniques such as tunable diode laser absorption spectroscopy that can be implemented in both ground and flight test efforts. We recently executed a measurement campaign at the exit of the combustor of the HIFiRE 2 ground test engine during Phase II operation of the engine. Data was collected in anticipation of similar data sets to be collected during the flight experiment. The ground test optical data provides a means to evaluate signal processing algorithms particularly those associated with limited line of sight tomography. Equally important, this in-stream data was collected to compliment data acquired with surface-mounted instrumentation and the accompanying flowpath modeling efforts-both CFD and lower order modeling. Here we discuss the specifics of hardware and data collection along with a coarse-grained look at the acquired data and our approach to processing and analyzing it.
Loosened Partisan Attachments and Receptivity to Incumbent Behaviors: A Panel Analysis, 1972-1976

An established hypothesis explaining the increased incumbency advantage is that incumbents reaped the benefit of the reduction in partisan identification's influence on the congressional vote. Briefly, the hypothesis maintains that as partisan identification's influence waned incumbent behavior's influence increased. The increased incumbency advantage is then the result of incumbents actively attracting voters whose decision is based less on partisan considerations and more on what incumbents offer. Using the 1972-76 NES panel study, we test this hypothesis by examining incumbent behavior's influence on voters with loosened partisan identification. The results support this premise. The interaction between incumbent behaviors and loosened partisan identifi cation increases the probability of an incumbent vote, attracting loosened challenger party identifiers and retaining loosened incumbent party identifiers. Finally, the results suggest that higher levels of incumbent activity increase the probability of ...
Surface ultrastructure of the isolated avian notochord in vitro: The effect of the perinotochordal sheath

The perinotochordal sheath (PNS) is a “tube” of extracellular matrix (ECM) that surrounds the avian notochord beginning in the second day of development. Somites, like the notochord, derive from chordamesoblast but are encased by a less substantial perisomitic matrix (PSM). Initially both tissue types exhibit epithelioid characteristics. Somitic cells subsequently disperse, however, while notochordal histoarchitecture is maintained until much later. To test the possible shape-preserving role of the PNS, notochords were isolated from chick embryos by homogenization (which retains the sheath) or by trypsinization (which removes the sheath). Somites were similarly isolated. Tissues were cultured 12-72 hours and studied by LM, SEM and TEM. Mechanically isolated notochords are initially rigid with smooth surfaces. During the culture period a few cells grow outward from cut ends of the notochord, but its overall rod shape and intact PNS are maintained. In contrast, uncultured trypsinized notochords are flaccid, denuded cylinders with numerous cytoplasmic blebs. They adhere to the substratum within 12 hours of culture when a few cells break away from the central tissue rod, migrate laterally, and appear mesenchymal. This cellular dispersion is directional (perpendicular to the long notochordal axis) and continuous (up to 72 hours). At this time a flattened ovoid growth area is formed. Cultured somites form flat circular growth areas within 12 hours of culture irrespective of the isolation method. These data suggest that the maintenance of an epithelial configuration by notochords in vivo may be due in part to physical restraints of the PNS. It seems possible that notochordal secretions (manifested by the formation of a PNS) could result in its compartmentation and axial confinement while its unrestrained somitic relatives are free to disperse.
Illustrative Material in Conversation Classes

Author's Summary— Illustrative material can claim a central place in conversation classes for sound pedagogical as well as didactical reasons. The article discusses in detail its didactical value 1) in vocabulary building (the descriptive picture), 2) as a guide for conversation (the action picture), 3) as a purveyor of topics (the associative picture).
A mechanical model for plate deformation associated with aseismic ridge subduction in the new hebrides arc

Tectonic features associated with a subducting fracture zone-aseismic ridge system in the New Hebrides island arc are investigated. Several notable features including a discontinuity of the trench, peculiar locations of two major islands (Santo and Malekula), regional uplift, and the formation of a basin are interpreted as a result of the subduction of a buoyant ridge system. The islands of Santo and Malekula are probably formed from an uplifted mid-slope basement high while the interarc basin of this particular arc is probably a subsiding basin instead of a basin formed by backarc opening. The situation can be modeled by using a thin elastic half plate overlying a quarter fluid space with a vertical upward loading applied at the plate edge. This model is consistent with topographic and geophysical data. This study suggests that subduction of aseismic ridges can have significant effects on tectonic features at consuming plate boundaries.
Harvesting implicit group attitudes and beliefs from a demonstration web site

Respondents at an Internet site completed over 600,000 tasks between October 1998 and April 2000 measuring attitudes toward and stereotypes of social groups. Their responses demonstrated, on average, implicit preference for White over Black and young over old and stereotypic associations linking male terms with science and career and female terms with liberal arts and family. The main purpose was to provide a demonstration site at which respondents could experience their implicit attitudes and stereotypes toward social groups. Nevertheless, the data collected are rich in information regarding the operation of attitudes and stereotypes, most notably the strength of implicit attitudes, the association and dissociation between implicit and explicit attitudes, and the effects of group membership on attitudes and stereotypes.
A p × p bit fraction model of binary floating point division and extremal rounding cases

We introduce the ordered series Fp×p of irreducible p × p bit fractions as a model of p-bit precision binary floating point division. We employ and extend results from the number theoretic literature on Farey fractions and continued fractions to provide a foundation for generation and analysis of the series Fp×p. An algorithm for ordered on-the-fly enumeration of a consecutive subsequence of Fp×p over a selected interval is introduced which requires only a couple of integer additions and/or subtractions per p × p bit fraction enumerated.We characterize two extremal rounding boundary sets, RNp, respectively RDp, of irreducible p × p bit fractions over the standard binade [1,2) whose 2p+O(1) member fractions have rational values that are each comparably close to a boundary for rounding to a normalized p-bit floating point number by round-to-nearest, respectively, by a directed rounding. A transformation is shown allowing either set RNp, RDp, to be simply computed from the other. We determine properties of these extremal rounding boundary sets RNp, RDp, and describe their use in the testing of floating point division implementations.
Exploring the performance of large-N radio astronomical arrays

New radio telescope arrays are currently being contemplated which may be built using hundreds, or even thousands, of relatively small antennas. These include the One Hectare Telescope of the SETI Institute and UC Berkeley, the LOFAR telescope planned for the New Mexico desert surrounding the VLA, and possibly the ambitious international Square Kilometer Array (SKA) project. Recent and continuing advances in signal transmission and processing technology make it realistic to consider full cross-correlation of signals from such a large number of antennas, permitting the synthesis of an aperture with much greater fidelity than in the past. In principle, many advantages in instrumental performance are gained by this 'large-N' approach to the design, most of which require the development of new algorithms. Because new instruments of this type are expected to outstrip the performance of current instruments by wide margins, much of their scientific productivity is likely to come from the study of objects which are currently unknown. For this reason, instrumental flexibility is of special importance in design studies. A research effort has begun at Haystack Observatory to explore large-N performance benefits, and to determine what array design properties and data reduction algorithms are required to achieve them. The approach to these problems, involving a sophisticated data simulator, algorithm development, and exploration of array configuration parameter space, will be described, and progress to date will be summarized.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Cortisol as an indicator of severity of parasitic infections of Haemonchus contortus in lambs (Ovis aries).

Two experiments were conducted with lambs to examine the effects of experimental infections of Haemonchus contortus on circulating cortisol levels. In both experiments, naive lambs were divided into three groups based on inoculum doses of 0 (control), 2000 (low dose) and 20,000 (high dose) infective larvae. In experiment 1, the lambs were sampled once daily from day 1 post-inoculation (p.i.) until day 39 p.i. Lambs from the high-dose group had significantly higher sustained levels of cortisol throughout the course of the infection than either the low-dose group or control lambs. In experiment 2, blood was sampled at 30-min intervals for 4 hr on day 21 p.i. The high-dose group also had highest cortisol levels. The consequences of chronic stress and the resultant elevated cortisol concentrations potentially could compromise animal health and animal well-being.
Inter-Regulation of Th17 Cytokines and the IL-36 Cytokines In Vitro and In Vivo: Implications in Psoriasis Pathogenesis

Accumulating evidence indicates that IL-1 family members and Th17 cytokines have a pathogenic role in psoriasis. We investigated the regulatory interactions of the IL-1-like IL-36 cytokine family and the Th17 cytokines in the context of skin inflammation. We observed increased gene expression of all three IL-36 cytokines in a Th17-dominant psoriasis-like animal model. The induction was downregulated by neutralizing IL-22. Expression of the IL-36s was also induced in cultured primary human keratinocytes (KC) by IL-17A and tumor necrosis factor (TNF)-α, and IL-22 synergized with IL-17A and TNF-α. Furthermore, the IL-36s directly induced their own expression and the production of proinflammatory mediators (TNF-α, IL-6, IL-8) in KC. These functions were markedly enhanced with the addition of IL-17A or TNF-α to the cultures. Similarly, IL-36α and IL-36β augmented IL-17A-mediated induction of antibacterial peptides. Finally, we show that the increased gene expression of IL-36 correlated with Th17 cytokines in the lesions of psoriatic patients. Our results indicate that the IL-36 cytokines are not only regulated by Th17 cytokines, but that they themselves can regulate the expression and enhance the function of Th17 cytokines. We propose that a feedback loop between the IL-36 and Th17 cytokines is involved in driving cytokine expression in psoriatic tissues.
The absorptive surface of Moniliformis dubius (Acanthocephala). I. Fine structure.

Abstract The fine structure of the syncytial epidermis of Moniliformis dubius (Acanthocephala) was examined with emphasis on the Streifenzone. Numerous crypts elaborate the area of the absorptive surface. Surface architecture is supported by a tripartite filamentous terminal web consisting of a 100 A sheet underlying the plasma membrane, a more extensive and diffuse inner region surrounding the crypts and a differentiated cytoplasmic annulation encircling each crypt neck. Inclusions and organelles described include filaments, microtubules, glycogen, lipid droplets, vesicles, mitochondria, Golgi complexes, endoplasmic reticulum and five lysosomal types. The eutelic nuclei contain little beterochromatin and have unusual nucleolar features.
Development of intelligent design associates: a case study.

Abstract A number of human factors data sets provides guidelines and recommendations for the system design process. Much of this information is available to the human factors engineer in design handbooks, textbooks, and periodicals. While human factors design information is both available and abundant, it is not necessarily readily accessible or in a format that is easily assimilated into a particular design scenario. This paper discusses the feasibility of incoporating human factors design data into intelligent, knowledge-based systems referred to as design associates . Successful implementation of any design associate is dependent upon two key issues: conversion of human factors data into a valid knowledge base, and overcoming the knowledge representation constraints imposed by an intelligent software tool. Detailed results of a recent effort to address these issues, and subsequently implement a design associate on a commercially available intelligent software tool, are presented. This particular associate, implemented in a rule-based tool environment, aids in the selection of visual display technologies.
Screening of point charges in Si quantum dots

The screening of point charges in hydrogenated Si quantum dots ranging in diameter from 10 A to 26 A has been studied using first-principles density-functional methods. We find that the main contribution to the screening function originates from the electrostatic field set up by the polarization charges at the surface of the nanocrystals. This contribution is well described by a classical electrostatics model of dielectric screening.
Relevance feedback in content-based image retrieval: some recent advances

Various relevance feedback algorithms have been proposed in recent years in the area of content-based image retrieval. This paper presents some recent advances: first, the linear and kernel-based biased discriminant analysis, BiasMap, is proposed to fit the unique nature of relevance feedback as a small sample biased classification problem. As a novel variant of traditional discriminant analysis, the proposed algorithm provides a trade-off between discriminant transform and density modeling. Experimental results indicate that significant improvement in retrieval performance is achieved by the new scheme. Secondly, a word association via relevance feedback (WARF) formula is presented and tested for unification of low-level visual features and high-level semantic annotations during the process of relevance feedback.
Hairy cell leukemia: current therapies and future directions

Hairy cell leukemia is a rare disease for which there are multiple treatment options. Purine nucleoside analogs (cladribine and pentostatin) are generally used for front-line treatment. Other active agents include interferon, rituximab and, although rarely, splenectomy. In the series published by Zinzani et al. in Cancer, the authors conclude that initial treatment for hairy cell leukemia should be maximized since these patients generally enjoy the highest complete response rates and the longest remission durations, and subsequent lines of therapy have lower response rates and more frequent relapses. However, evolving immunohistochemical and molecular diagnostic techniques, as well as criteria for evaluating response to therapy and clinical trials investigating chemoimmunotherapy, may result in clinicians re-evaluating how patients are treated in the front-line and when treatment should be initiated for relapsed patients.
Reconfigurable Spacecraft Controller Design via Location-Scheduled Control

T HIS Note proposes a new strategy for the design of the attitude determination and control system (ADCS) of reconfigurable spacecraft, with a specific application example to so-called nanosatellites. These spacecraft adhere to the CubeSat standard [1], and the natural discretization of the overall volume into cube units makes them a popular platform for research into spacecraft reconfiguration [2]. The proposed design strategy, called location-scheduled control (LSC), seeks to reduce the development time required for the ADCS of a reconfigurable spacecraft conducting scientific research. In traditional ADCS design, mission science requirements levy pointing requirements onto the ADCS, which drive sensor and actuator selection. Once the ADCS hardware has been chosen, an appropriate control algorithm is selected and tested. In contrast, the location-scheduled approach to ADCS design is a two-phase process. In the first phase, a general purpose self-contained ADCS hardware unit is designed by selecting a suite of sensors and actuators that are appropriate for a class of science missions. Controller gains and ADCS location are then optimized in simulation for a number of generic science payloads, such as those depicted in Fig. 1, in which payload cube (P) layouts dictate possible locations for the ADCS (cubes A or B). In the second phase of the process, one of the previously tested configurations is selected based on the needs of the current science mission. Some amount offine gain tuningwill inevitably be required, but if a member of the catalog of spacecraft configurations satisfies the needs of the science payload, the developer need not return to the first phase of the design process. Although the LSC approach is applicable for many reconfigurable spacecraft, thiswork considers a nanosatellite ADCSdesign problem to demonstrate this methodology. The objective of the design problem is to find the optimal combination of ADCS unit location and control law gainvalues for a nanosatellite performing a detumble maneuver in which the spacecraft has high initial angular velocity and arbitrary initial orientation. Using the CubeSat standard, a 10 10 10 cm cube is designated as one unit of volume (abbreviated 1U), and complete spacecraft are created from these cubes. Traditional CubeSats are typically no larger than 3U in volume, and they have largely been passively controlled via permanent magnets [3,4], gravity gradient booms, or aerodynamic stabilization. This Note focuses on spacecraft that are 6U in volume (as in Fig. 1), with overall dimensions of 10 20 30 cm. This form factor creates greater volume for both complex science payloads and attitude control hardware and is currently under development at NASAAmes Research Center. A nonlinear control law introduced in [5] is used to control the nanosatellite using actuators for which the control authority is restricted by a known upper bound.
Potentially functional polymorphism in the promoter region of prodynorphin gene may be associated with protection against cocaine dependence or abuse

It has been demonstrated that the opioid peptide dynorphin plays a role in modulating responses to several psychoactive substances including cocaine. Our laboratory and others have found that mRNA levels of dynorphin in the caudate and putamen are elevated after acute or chronic cocaine exposure in rats. Recently, a 68-base pair (bp) repeat polymorphism within the core promoter region of the human prodynorphin gene has been reported to occur in alleles containing one, two, three, or four copies. This repeat contains a putative AP-1 transcription factor binding site; reporter gene constructs with three or four, but not one or two, copies of the tandem repeats were shown to be associated with increases in transcriptional activation in in vitro cellular assays. We hypothesize that this polymorphism may be associated with individual differences in vulnerability to cocaine dependence or abuse. From an ongoing study of the genetics of addiction, 174 subjects were studied, including individuals with a primary diagnosis (DSM-IV criteria) of cocaine dependence (N = 61) or abuse (N = 22), and controls with no history of any substance dependence or abuse (N = 91). We designed primers for polymerase chain reaction (PCR) to amplify sequences of the promoter region of the prodynorphin gene containing the repeat element. The association of alleles containing three or four repeats with cocaine dependence/abuse was examined. With data stratified by ethnic group, pooled relative risk (RR) with Mantel-Haenszel Chi square was calculated: RR = 0.59 (95% confidence interval 0.37–0.95), χ2(1) = 4.14, P = 0.042. Our results suggest that this allelic variation at the promoter region of the prodynorphin gene (alleles with three or four repeats), which may result in enhanced transcription of the gene, may contribute to relative protection and decrease individual vulnerability to develop cocaine dependence or abuse. © 2002 Wiley-Liss, Inc.
M13 bacteriophage and pUC plasmids containing DNA inserts but still capable of β-galactosidase α-complementation

A DNA fragment encoding the transposon Tn9 chloramphenicol acetyltransferase gene (cat) was inserted into M13 phage and pUC plasmid cloning vehicles. When the cat gene was inserted in the same orientation as the lacZ gene, two new polypeptides were produced. One polypeptide possessed chloramphenicol acetyltransferase activity, while the other expressed beta-galactosidase alpha-donor activity. Both new polypeptides were translated from a hybrid messenger RNA initiating from the lac promoter. These observations may help explain why not all inserts produce white plaques.
THE ENDOCRINOLOGY OF OBESITY

Obesity is associated with multiple endocrine alterations as defined by changes in the level of circulating hormones and changes in the pattern of secretion or clearance of these circulating molecules. Of these alterations, some are most certainly secondary to the development of obesity, whereas others may be putative causative factors. This article reviews the known alterations in the classic endocrine systems (i.e., hypothalamic–pituitary–end organ and the endocrine pancreas), as well as discusses several new potential endocrine factors and their relationship to obesity. Animal experimentation is discussed when relevant, although the focus is on human endocrinology. The role of each factor in the pathogenesis of obesity is discussed from the viewpoint of association and causation. The latter category is discussed for the most part through reexamination of the post-obese patient and animal experimentation. Although the data may be suggestive, they are not direct proof of causation in humans. Techniques for the study of circulating hormones have become more widely available in recent years. The practicing physician attempting to detect subtle endocrine changes faces several diagnostic challenges which are reviewed herein from a practical perspective. This is especially relevant to a discussion of the hypothalamic-pituitary-gonadal axis (in men) in which the separation of the hypogonadal state from the alterations related to obesity, per se, makes decisions regarding the appropriateness of replacement therapy difficult. Similar issues are pertinent in discussions of the growth hormone (GH)–insulinlike growth factor (IGF) axis, and in the hypothalamic-pituitary-adrenal axis and changes linked to Cushing's disease. Several hormones are not discussed herein [including vasopressin, norepinephrine, epinephrine, glucagon, endorphins, vasoactive intestinal peptide (VIP), enterostatin, and other gut peptides]. Readers are referred to other articles in this issue for reviews.
A Review on Synthesis of High Performance Composites from Zircon

The latest development of ZrC-SiC, ZrO2-SiC and ZrO2-mullite high performance composites synthesized from zircon was reviewed. The future development of synthesizing high performance composites from cheap materials and simple preparation technology was prospected.
A Reversal of Fortunes Black Empowerment, Political Machines, and City Jobs in New York City and Chicago

Contrary to theoretical predictions, blacks have been more successful at acquiring municipal jobs in New York City than in Chicago. Moreover, the reverse was true earlier in the century: Blacks were once better represented in city jobs in Chicago. Using longitudinal data and historical accounts, the author argues that this reversal of fortunes happened because blacks were able to mobilize and exploit a critical juncture in political development—the decline of the political machine—earlier in New York City than in Chicago.
Sustainable Research, Development, and Demonstration (RD&D)†

The major theme of the 21st International Symposium on Chemical Reaction Engineering (ISCRE 21) is sustainable development. Many of the critical sustainable development challenges revolve around: energy, resources, food, water, and environment. Successful developments require sustainable resource-use strategies, processes, products, and services. In addition, the major challenges that we face are long-term, massive in scale, and have high future uncertainty. Sustainable developments must work now, work in the future, not put off addressing the problem, and not disadvantage future generations. These are tall challenges. Sustainability in research, development, and demonstration (RD&D) faces these same challenges and must fit into a similar framework. CRE is an important activity contributing to all aspects of RD&D. Sustainable RD&D supports both short-term and long-term needs, provides for a broad range of options, and continuously evolves to address progress made and shifts in future needs. Sustainable RD...
Concentration of Nitrate and Nitrite in Raw Turkey Breast Meat and the Microbial Conversion of Added Nitrate to Nitrite in Tumbled Turkey Breast Meat

Abstract The concentrations of nitrate and nitrite in raw turkey breast meat and the microbial conversion of nitrate to nitrite in an uncured tumbled breast meat product were studied to assess their involvement in the formation of undesirable pinkness. Nitrate concentration in raw turkey breast meat ranged from 3.8 to 21 ppm and nitrite varied from 0 to .7 ppm. Microorganisms in the tumbled meat sample converted the nitrate to nitrite; 5.2 ppm of nitrite (NaNO2) were formed from 100 ppm of added nitrate (KNO3) during 40 h of storage at 4 C. It was concluded that if a high amount of nitrate and a long storage period were combined in tumbled turkey breast meat, the probability of the development of a pink color in the oven-roasted product would be very high.
Comparison of 3H-galactose and 3H-glucose as precursors of hepatic glycogen in control-fed rats.

Labeling of hepatic glycogen derived from 3H-galactose and 3H-glucose was compared shortly after intravenous injection in control-fed rats. The rats were allowed to accumulate 5-8% glycogen prior to receiving label. Fifteen minutes to 2 hours after labeling, liver was excised and processed for routine light (LM) and electron microscopic (EM) radioautography (RAG) or biochemical analysis. After injection of 3H-galactose, LM-RAGs revealed that the percentage of heavily labeled hepatocytes increased from 37% after 15 minutes to 68% after 1 hour but showed no further increase after 2 hours. alpha-Amylase treatment removed most glycogen and incorporated label; thus few silver grains were observed, indicating little incorporation of label except into glycogen. EM-RAGs demonstrated that most label occurred where glycogen was located. Biochemical analysis showed initially a high blood level of label that rapidly plateaued at a reduced level by 5 minutes. Concomitantly, glycogen labeling determined by liquid scintillation counting reflected the increases observed in the RAGs. After injection of 3H-glucose, LM-RAGs revealed that only 12% of the hepatocytes were heavily labeled at 1 hour and 20% at 2 hours. In tissue treated with alpha-amylase, glycogen was depleted and label was close to background level at each interval observed. EM-RAGs showed most grainsmore » associated with glycogen deposits. Biochemically, blood levels of label persisted at a high level for 30 minutes and tissue levels increased slowly over the 2-hour period. This study shows that incorporation from 3H-galactose was more rapid than incorporation of 3H-glucose; however, label derived from both carbohydrates appeared to be incorporated mainly into glycogen.« less
Debye-series analysis of the first-order rainbow produced in scattering of a diagonally incident plane wave by a circular cylinder

We derive the Debye-series expansion of the partial-wave scattering and interior amplitudes for the interaction of a diagonally incident beam of arbitrary profile with an infinitely long homogeneous dielectric circular cylinder. We then discuss the physical interpretation of the various terms of the series. We also consider the one-internal-reflection Debye-series terms for diagonal plane-wave incidence and examine the first-order rainbow extinction transition as a function of the tilt angle of the incident plane wave. We experimentally observe the first-order rainbow extinction transition and compare our observations with the Debye-series predictions.
Acquiring Metastatic Competence by Oral Squamous Cell Carcinoma Cells Is Associated with Differential Expression of α-Tubulin Isoforms

We performed comparative global proteomics analyses of patient-matched primary (686Tu) and metastatic (686Ln) OSCC cells. The metastatic OSCC 686Ln cells showed greater in vitro migratory/invasive potential and distinct cell shape from their parental primary 686Tu cells. Ettan DIGE analysis revealed 1316 proteins spots in both cell lines with >85% to be quantitatively similar (<2 folds) between the two cell lines. However, two protein spots among four serial spots were highly dominant in 686Ln cells. Mass spectrometry sequencing demonstrated all four spots to be α-tubulin isotypes. Further analysis showed no significant quantitative difference in the α-tubulin between the two cell lines either at mRNA or protein levels. Thus, two distinct isoforms of α-tubulin, probably due to posttranslational modification, were associated with metastatic 686Ln cells. Immunofluorescence demonstrated remarkable differences in the cytosolic α-tubulin distribution patterns between the two cells. In 686Tu cells, α-tubulin proteins formed a normal network composed of filaments. In contrast, α-tubulin in 686Ln cells exhibited only partial cytoskeletal distribution with the majority of the protein diffusely distributed within the cytosol. Since α-tubulin is critical for cell shape and mobility, our finding suggests a role of α-tubulin isoforms in acquisition of metastatic phenotype and represents potential target for therapeutic intervention.
Inadvertent Subdural Injection during Cervical Transforaminal Epidural Steroid Injection

Serious complications following cervical epidural steroid injection are rare. Subdural injection of local anesthetic and steroid represents a rare but potentially life threatening complication. A patient presented with left sided cervical pain radiating into the left upper extremity with motor deficit. MRI showed absent lordosis with a broad left paramedian disc-osteophyte complex impinging the spinal cord at C5-6. During C5-6 transforaminal epidural steroid injection contrast in AP fluoroscopic view demonstrated a subdural contrast pattern. The needle was withdrawn slightly and repositioned. Normal lateral epidural and nerve root contrast pattern was subsequently obtained and injection followed with immediate improvement in radicular symptoms. There were no postoperative complications on subsequent clinic follow-up. The subdural space is a potential space between the arachnoid and dura mater. As the subdural space is larger in the cervical region, there may be an elevated potential for inadvertent subdural injection. Needle placement in the cervical subdural space during transforaminal injection is uncommon. Failure to identify aberrant needle entry within the cervical subdural space may result in life threatening complications. We recommend initial injection of a limited volume of contrast agent to detect inadvertent subdural space placement.
A survey of anycast in IPv6 networks

Anycast is a new "one-to-one-of-many" communication method in IPv6 networks. With this technology, the problem of finding the best server to respond to a request becomes a virtual noop. Hindered by unresolved issues and the slow deployment of IPv6, network-layer anycast is still not a reality. However, an increase in interest and research surrounding anycast recently warrants a look at the state and direction of the ideas in this area. This article describes some of the major problems with network-layer anycast and their possible solutions, as well as some optimizations and applications that have been developed recently.
Binocular vision in theropod dinosaurs

ABSTRACT The binocular fields of view of seven theropod dinosaurs are mapped using sculpted life reconstructions of their heads and techniques adopted from ophthalmic field perimetry. The tall, narrow snout and laterally facing eyes of the allosauroids Allosaurus and Carcharodontosaurus restricted binocular vision to a region only approximately 20° wide, comparable to that of modern crocodiles. In contrast, the coelurosaurs Daspletosaurus, Tyrannosaurus, Nanotyrannus, Velociraptor, and Troodon had cranial designs that afforded binocular fields between 45–60° in width, similar to those of modern raptorial birds. Binocular field width and predatory style (ambush versus pursuit) is examined for extant taxa, along with a discussion of cranial adaptations that enhance binocular vision. The progressive increase in frontal vision in the tyrannosaurids culminates in broader binocular overlap than that of a modern hawk. The visual acuity and the limiting far point for stereopsis is estimated for Tyrannosaurus base...
Allantoate amidohydrolase transcript expression is independent of drought tolerance in soybean

Drought is a limiting factor for N2 fixation in soybean [Glycine max (L.) Merr.] thereby resulting in reduced biomass accumulation and yield. Drought-sensitive genotypes accumulate ureides, a product of N2 fixation, during drought stress; however, drought-tolerant genotypes have lower shoot ureide concentrations, which appear to alleviate drought stress on N2 fixation. A key enzyme involved in ureide breakdown in shoots is allantoate amidohydrolase (AAH). It is hypothesized that AAH gene expression in soybean determines shoot ureide concentrations during water-deficit stress and is responsible for the differential sensitivities of the N2-fixation response to drought among soybean genotypes. The objectives were to examine the relationship between AAH transcript levels and shoot ureide concentration and drought tolerance. Drought-tolerant (Jackson) and drought-sensitive (Williams) genotypes were subjected to three water-availability treatments: well-watered control, moderate water-deficit stress, and severe water-deficit stress. Shoot ureide concentrations were examined, in addition to gene expression of AAH and DREB2, a gene expressed during water-deficit stress. As expected, DREB2 expression was detected only during severe water-deficit stress, and shoot ureide concentrations were greatest in the drought-sensitive genotype relative to the drought-tolerant genotype during water-deficit stress. However, expression of AAH transcripts was similar among water treatments and genotypes, indicating that AAH mRNA was not closely associated with drought tolerance. Ureide concentrations in shoots were weakly associated with AAH mRNA levels. These results indicate that AAH expression is probably not associated with the increased ureide catabolism observed in drought-tolerant genotypes, such as Jackson. Further study of AAH at the post-translational and enzymatic levels is warranted in order to dissect the potential role of this gene in drought tolerance.
Model-based echolocation of environmental objects

This paper presents an algorithm that can recognize and localize objects given a model of their contours using only ultrasonic range data. The algorithm exploits a physical model of the ultrasonic beam and combines several readings to extract outline object segments from the environment. It then detects patterns of outline segments that correspond to predefined models of object contours, performing both object recognition and localization. The algorithm is robust since it can account for noise and inaccurate readings as well as efficient since it uses a relaxation technique that can incorporate new data incrementally without recalculating from scratch. >
Traumatic Rupture of the Aorta: Emergency Operation

Abstract Fifty-nine patients who had traumatic aortic rupture in the area of the isthmus and were treated less than one week after injury were studied. Most patients (N = 47) underwent repair using pump-oxygenator partial bypass; 7 had simple cross-clamping. Paraplegia developed in 4 during operation. One patient died of a head injury after receiving heparin for bypass. The experience with these patients and a critical review of the literature indicate that the use of extracorporeal circulation and avoidance of hypoxia and hypercapnia may decrease the probability of paraplegia. When laparotomy preceded thoracotomy, there were no clearly deleterious effects of heparinization.
Combined dynamic contrast enhanced breast MR and proton spectroscopic imaging: A feasibility study

Purpose: To investigate the feasibility of combined dynamic contrast enhanced (DCE) and magnetic resonance spectroscopy (MRS) in evaluating breast lesions. Methods: Nine patients with positive mammograms scheduled for either biopsy or mastectomy were examined on a 1.5-T MR scanner. DCE was performed with administration of gadolinium-DTPA contrast using a two-dimensional spoiled gradient recall echo (SPGR) sequence. Proton spectroscopy (TR/TE 2000/272 msec) was performed using PRESS single slice (10 mm). Lesion time intensity curves were classified as persistent (type 1), plateau (type 2), or washout (type 3) pattern enhancement. Choline (Cho) signal-to-noise ratios (SNRs) and enhancement patterns were compared between benign and malignant lesions as determined by histopathology. Results: Five patients had breast carcinoma and four had benign lesions. Type 1 enhancement was found in two benign cases, type 2 enhancement in two of four benign and four of five malignant lesions, and one malignant case exhibited a type 3 pattern. Choline SNR was significantly different (P 0.003) between benign and malignant lesions (2.0 0.3 vs. 5.7 1.4; P 0.003). Choline SNR was less than 4.0 in all of the benign lesions, including the two lesions with type 2 enhancement. Conclusion: Proton MRS appears to be a promising technique for classification of breast lesions when DCE results are equivocal. A combination of DCE and MRS is feasible, and may have improved specificity compared to either modality alone.