cssi/SciSciGPT-SciSciNet huggingface dataset:
Two-dimensional iterative region-of-interest (ROI) reconstruction from truncated projection data.

A small detector or limited gantry rotation angles may cause data truncation, in which case the entire object cannot be completely reconstructed. However, a small region of interest (ROI) may be recoverable in certain truncation situations. Two analytical methods have been proposed for exact ROI reconstruction. Here we evaluate the capability of ROI reconstruction using an maximum-likelihood expectation-maximization (ML-EM) method, which directly solves the inverse problem of the system equations. ROI reconstruction using the ML-EM method is compared with that using the two analytical methods. Comparisons are based on reconstructions of four specifically designed, computer-simulated truncation cases. In the simulation, each reconstructed ROI is coupled with its counterpart in the nontruncated case to evaluate the accuracy of the reconstructed ROI. We found that, (a) in two truncation situations the ROI can be reconstructed by both the analytical methods and the two-dimensional ML-EM method, but the ML-EM method may produce a larger ROI; (b) for a truncation case [Fig. 3(c)] that neither analytical algorithm is applicable, the ML-EM method provides a quantitative ROI reconstruction; and (c) for the well-known “interior” truncation problem, neither the analytical methods nor the ML-EM method can perform an exact ROI reconstruction, but the ML-EM method provides informative ROI images. We also propose an analysis using the truncated projection matrix and its Moore-Penrose inverse matrix which can help to determine the recoverable ROI using iterative methods for a given truncation situation.
Nutrient pulses, plankton blooms, and seasonal hypoxia in western Long Island Sound

Development of seasonal hypoxia was studied weekly in the western narrows of Long Island Sound (WLIS) during the summers of 1992 and 1993 by measuring hydrographic properties, biological oxygen demand (BOD), biomass, production, and mortality of phytoplankton and bacterioplankton in the water column. Dissolved oxygen in bottom waters was low and variable during stratified periods (19–51% saturation), oscillating in and out of hypoxic conditions (defined as <3 mg O2 l−1 or 94 μM O2). Hypoxia was more prevalent in 1993 than in 1992, corresponding to greater water column stratification in 1993. Microbial BOD in bottom waters appeared to be fueled by delivery of autochthonous carbon from phytoplankton blooms rather than allochthonous carbon input. Phytoplankton production responded to elevated NH4 + concentrations, especially when the mixed layer was shallow. NH4 + concentrations generally varied as a function of the preceding week's rainfall (r2=0.765). Bacterial production did not covary with phytoplankton production, yet was closely correlated with particulate organic carbon, which was chlorophyll-rich. Results indicate that the timing and severity of hypoxia development are strongly coupled to allochthonous input of NH4 + after heavy precipitation. Observations illustrate for the first time that bottom waters in this system oscillate in and out of hypoxia on an almost weekly basis rather than sustain them over the entire stratified period. The frequency of these oscillations depends upon variations in nutrients, planktonic production and export, and bottom water ventilation.
Undulators as Sources of Synchrotron Radiation

At the present time the first generation of facilities having electron storage rings designed for and dedicated to synchrotron radiation research are beginning operations in the US, Europe and Japan. The use of wigglers and undulators as enhanced sources of synchrotron radiation plays an important role at all these facilities. Moreover, recently there has been much activity in the design of the next generation machines, which will place even greater, and perhaps exclusive, emphasis on the use of wigglers and undulators. The operation of these insertion devices has been made even more attractive by advances in the design and construction of permanent magnet wigglers and undulators. This reliable and economical technology eliminates the need for more complex superconducting magnets, except to achieve very high magnetic fields for the production of hard photons from relatively low energy rings. We review the spectral properties of the radiation, emphasizing the complementary aspects of time- and frequency-domain analyses. We next study the brightness of the undulator source. Finally, we consider some limitations associated with operating an undulator in a storage ring.
Avian gastrointestinal anatomy and physiology

A bird's gastrointestinal (GI) tract morphology, digestive strategy, and metabolic capability have been intimately intertwined during evolution to match the nutrient content and physical attributes of foods available in its natural habitat. The most commonly kept companion species are granivorous with a tendency toward omnivory. The beak, oral cavity and tongue of granivorous birds have anatomic adaptations for shelling seeds, including ridges in the tomia of their beak for slicing the hull and a dexterous tongue for manipulating the seed and disposing the hull. Granivorous species possess a sizeable crop or an expandable esophageal pouch for storing food so that large meals can be consumed. Their proventriculus is somewhat small, and their gizzard is large, muscular, and possesses a thick cuticle relative to carnivores or frugivores. A vestigial ceca and short rectum provide little area for use of symbiotic bacteria to aid in the digestion of the fibrous components of food.
An approach to summarizing interrelations between functions used in radiotherapy dose calculations

An approach to summarizing interrelations between functions used in radiotherapydose calculations is suggested. A mnemonic diagram is proposed which should be useful for radiationphysicists in radiotherapy to obtain at a quick glance the definitions and interrelations between the commonly used functions like back‐scatter factor, percent depth dose, tissue–air ratio, scatter–air ratio, and scatter function. The conditions under which the measurements must be made for these functions and interrelations to be valid are described. Rules for application of the diagram and some practical examples are included. The diagram also serves as a very effective teaching aid.
Infant Emotionality: Observational Methods and the Validity of Maternal Reports

This study was designed to improve the observational measurement of emotionality, and to test factors that influence the validity of maternal reports. More than 150 infants were visited at home with their mothers, two thirds of whom were depressed. These visits yielded 4 different observational measures of positive and negative emotionality at both 6 and 9 months. These were standard assessments (based on LabTab), naturalistic interactions, atypical reactions to the standard assessments, and the still-face procedure. Atypical reactions were consistently related to traditional measures of emotionality. Responses to the still-face procedure also generally cohered with the other measures. Aggregation improved agreement between mothers and observers. Depressed mothers' reports of negative emotionality were less accurate at 6 months than those of nondepressed mothers. Parenting experience appeared to be associated with greater maternal accuracy. Taken together the findings provide some support for both sides o...
Preparation, electrical and mechanical properties of vapor grown carbon fiber (VGCF)/vinyl ester composites

Abstract Vapor grown carbon nanofiber (VGCF)/vinyl ester composites were prepared. Their volume electrical properties exhibited percolation behavior with a sharp drop in resistivity occurring between 2 and 3 wt% VGCF loading. Composites made from nitric acid-oxidized VGCF were insulators even at: 15 wt% VGCF loading. Unpolished samples had thin resin-rich outer layers observed by SEM, which affected their resistivity behavior. The effects of fiber diameter, heat treatment and fiber/resin mixing were examined. Incorporating VGCF had little influence on flexural moduli, decreased flexural strengths and T g and increased storage moduli, E ′, both above and below T g .
Prediction of inherited and genetic mutations using the software model checker SPIN

Genetic testing is becoming an important tool for detection of many genetic diseases. Designing a genetic test requires accurate data and an efficient means of comparing sequences that are present in the databases. However, as prodigious amount of data continue to emerge, querying the database to make important predictions is becoming arduous. It is essential that better tools be designed to analyze these data. In this paper, a model-based approach to gene tests and the analysis of metabolic pathways is proposed. Gene sequences and metabolic processes are modeled using formal language, and predictions are made through the verification mechanism of a software model checker. The technique is demonstrated with models of genes for cystic fibrosis tranmembrane conductance regulator protein and the map kinase pathway.
β‐Spiral conformations of the elastomeric polytetrapeptides, (VPGG)n and (IPGG)n, by 2D NMR and molecular mechanics studies

The synthetic polytetrapeptide using the repeating sequence VPGG found in the fibrous protein, elastin, exhibits a reversible inverse temperature transition, i.e., the molecular order increases on raising the temperature of the polypeptide in aqueous solutions. The matrices formed from the coacervate by γ-irradiation-induced cross-linking exhibit an elastic modulus and temperature dependence of elastomeric force with similarity to that of fibrous elastin. As demonstrated on poly(VPGVG), which forms a β-spiral structure with recurring Type II β-turns, the molecular structure of the elastin-based polypeptides is fundamental to an understanding of the mechanism of elasticity. It was found previously that the repeating unit VPGG in the polytetrapeptide forms a Type II β-turn with a hydrogen bond between Val1 CO and Gly4 NH. This secondary structural feature is confirmed in this report by 2D NMR data as indicated by specific NOE cross-peaks, particularly, dNN(3,4), dαN(2,3), dαN(2,4), and dγN(1,4). The same secondary structural feature is found in the 2D NMR data for its analog polypeptide, poly(IPGG). The NMR data provide conclusive evidence for the Type II β-turn secondary structure. Molecular mechanics computations were performed to develop a more detailed tertiary structure for the polytetrapeptides. The ECEPP/2 potential field and build-up strategy were employed in mapping conformational space of VPGG and its high polymer. In addition, helical structures are sought using the Go–Scheraga condition, on the assumption that the repeated sequence would preferentially adopt a helical or nearhelical conformation on optimization of intramolecular hydrophobic contacts. A number of structures with helically recurring β-turns was obtained and can be used as starting structures in future studies that are to include hydration. The structures were also evaluated in terms of potential energy using the CHARMm force field.
Surface finish and treatment on iron substrates for electronic packaging

Iron (Fe) with small percentage of carbon (less than 0.2%) is known as low carbon steel. It has numerous industrial applications since the Iron Age. It possesses high strength, high melting point, and low CTE. It is very inexpensive. The downside is fair thermal conductivity, which can be compensated using thinner substrates and thinner solder layer. The other downside is that it rusts easily and its oxides dissolve in water. In this research, we explored techniques to treat its surfaces to achieve finishes compatible with electronic packaging processes. These methods include electroplating of nickel (Ni), tin (Sn), respectively. With these finishes, we demonstrated that Si chips can be strongly bonded to Fe substrates using Sn without any flux.
Trichinella spiralis: IgM and IgG and infectivity for mice

Abstract Serum collected from rabbits given multiple inoculations of Trichinella spiralis reduced infectivity of the larvae when preincubated in immune whole serum. After gel filtration of the serum, antiparasitic activity was found to be associated with the IgM (19S) fraction as measured by the reduced number of adult worm and larva recoveries. Preincubation of the larvae with IgG (7S) showed no effect on the infectivity of the larvae.
Managing Radical Organizational Change

Karen L. Newman and Stanley D. Nollen, in their book ‘Managing Radical Organizational Change,’ examine the transformation of six companies in the Czech Republic as they adapted to the economic transitions of the 1990s. The book presents detailed case analyses of each of the firms, and the authors interpret these cases in terms of a set of research questions about organizational change derived from a comprehensive review of contemporary organization theory. The authors, both of Georgetown University, have had extensive experience as teachers, researchers, and consultants with a number of firms in the Czech Republic.
Seyfert galaxy ultraviolet emission-line intensities and variability - A self-consistent photoionization analysis applied to broad-line-emitting gas in NGC 3783

Well-constrained photoionization models for the Seyfert I galaxy NGC 3783 are developed. Both cross-correlation analyses and line variability trends with varying ionizing radiation flux require a multicomponent picture. All the data for He II 1640 A, C IV 1549 A, and semiforbidden C III 1909 A can be reasonably well reproduced by two cloud components. One has a source-cloud distance of 24 lt-days, gas density around 3 x 10 exp 10/cu cm, ionization parameter range of 0.04-0.2, and cloud thickness such that about half of the carbon is doubly ionized and about half is triply ionized. The other component is located approximately 96 lt-days from the source, is shielded from the source by the inner cloud, has a density about 3 x 10 to the 9th/cu cm, and is characterized by an ionization parameter range of 0.001-0.03, The cloud thickness is such that about 45 percent carbon is doubly ionized and about 55 percent is singly ionized.
Scientific Basis for Nuclear Waste Management

As a result of the Reagan administration's commitment to nuclear energy as a significant future energy source and of attempts by the 97th Congress to grapple with legislative aspects of the problem, increased attention has focused recently on the problem of safely disposing of nuclear waste. These proceedings of the Third Symposium on Nuclear Waste Management of the Materials Research Society provide insight into the status of investigations on the subject as of late 1980. As with volumes 1 and 2 of this series, the 77 contributions are all short progress reports of ongoing research with the emphasis fittingly on materials science. Readers who wish extensive background material on the problems of nuclear-waste management and disposal, details of specific sites, or overviews of the programs of research in this country and abroad will have to look elsewhere.
Conical extrusion of a work-hardening material: an asymptotic analysis

We study steady-state conical extrusion of an isotropic, power-law hardening material with a Coulomb friction condition present at the die faces. An asymptotic theory is developed based on an axial velocity field which is nearly “slug-like”, i.e., a deformation field for which the transverse variations of the axial velocity are modest in size. However, although the velocity is ‘slug-like”, within the asymptotic limit considered the shear stresses are not negligible compared to the longitudinal deviatoric stresses. For this reason the theory accounts for the first manifestations of inhomogeneous deformation. In practical terms the validity of the asymptotic theory generally requires either the friction coefficient µ to be small or the die slope Δh/L to be small (where Δh is the radius reduction and L the die length). The primary result of the work is the set of equations (76)–(78). In addition, the present formulation enables for the first time the development of a model of inhomogeneous deformation in conical extrusion which is analogous to the very popular inhomogeneous deformation theory developed by Orowan for plane-strain sheet rolling. Results are presented for a number of examples illustrating the depature from a state of homogeneous compression which is typically found.
Improving Listening in Content Area Subjects

The ability to listen attentively and critically, the authors state, is crucial. In the following article they describe two techniques for improving listening skills.
Liquid Structures and Glass Formation

Glasses have the structures of those liquids from which they formed on cooling. The structures of liquids are the key to the understanding of glass formation. Weyl and Marboe assume three extreme cases of liquid structures. (1) Sodium chloride melts under disproportionation of all binding forces, forming abruptly a very fluid melt which consists of ionic clusters separated by fissures (Frenkel-type liquid). (2) Organic compounds of high molecular weight consist of molecules with strong intramolecular forces and weaker intermolecular forces. Depending on the shape and size of these molecules, the liquids undergo orientation when stretched (orientable liquid of the Stewart type). (3) Cristobalite and many silicates (albite) melt because increased thermal motion gradually overcomes the binding forces in the crystal. Melting is a gradual process; the optical properties of the crystal are retained for long times above the melting temperature. The resulting “flawless” liquid of the Bernal type can be easily supercooled and forms a glass. Glass formation does not take place from atomic liquids (argon, most metals) nor from low molecular-weight liquids (benzene, carbon tetrachloride) but from liquids whose structures correspond to (2) and (3) of the idealized structures. The structure of liquids which can form glasses is discussed on the basis of a ternary diagram, the corners of which are representing the three idealized extreme structures. Conventional thermodynamic treatment can not distinguish between the average bond strength and a distribution of bond strengths. The average bond strength might be the same for (1), (2), and (3). Even if one could derive the distributions of all binding forces within a condensed system, one still cannot distinguish between the structures (2) and (3), because the difference lies in the lifetime of the “clusters” (short life) and the “molecules” (long life).
The plutonium-magnesium system

Abstract Experimental determination of phase behavior within the Pu-Mg binary system has been completed using metallography, electron microprobe, X-ray powder diffraction, and differential thermal analysis (DTA). Decompositional temperatures and lattice parameters were determined for two intermetallic phases, PuMg4 and PuMg6. Additionally, solid and liquid solubilities were characterized from 510 to 1095°C. A new construction of the binary phase diagram is presented which reflects our data along with the work of previous researchers. Thermodynamic properties for the liquid phase were derived from the revised phase boundary of the liquid miscibility gap determined in this investigation.
Thromboelastographic evaluation of dogs with congenital portosystemic shunts.

Background On plasma-based assays, dogs with congenital portosystemic shunts (CPSS) have changes in serum concentrations of both pro- and anticoagulant proteins, but how these abnormalities affect whole blood coagulation assays (eg, thromboelastography) are unknown. Objectives To conduct kaolin-activated thromboelastography (TEG) analysis in dogs with CPSS and to compare TEG coagulation status with clinical presentation, routine serum biochemistry, and plasma-based coagulation tests. Animals Twenty-one client-owned dogs with CPSS confirmed by ultrasound examination or nuclear scintigraphy. Methods In a prospective study, signalment, clinical presentation, TEG analysis, CBC, serum biochemistry, and hemostatic tests (platelet count, prothrombin time [PT], activated partial thromboplastin time [aPTT], quantitative fibrinogen, antithrombin [AT] activity, protein C [PC] activity, d-dimers, and factor VIII activity) were analyzed in dogs with CPSS. Results Dogs with CPSS had significantly shorter K values and increased angle, maximum amplitude (MA), and G values compared with the reference population. On plasma-based coagulation testing, dogs with CPSS had significantly prolonged PT, lower platelet counts, lower AT and PC activities, and increased d-dimers and factor VIII activity. Evaluation of G value defined 9/21 dogs with CPSS as hypercoagulable. These dogs were more likely to have hepatic encephalopathy (HE) than CPSS dogs that had normal coagulation. Conclusions and Clinical Importance TEG analysis detected hemostatic abnormalities consistent with a hypercoagulable state in some dogs with CPSS. The presence of a hypercoagulable state was 40 times more likely in dogs with symptomatic HE.
Optimized Pedestrian Detection for Multiple and Occluded People

We present a quadratic unconstrained binary optimization (QUBO) framework for reasoning about multiple object detections with spatial overlaps. The method maximizes an objective function composed of unary detection confidence scores and pairwise overlap constraints to determine which overlapping detections should be suppressed, and which should be kept. The framework is flexible enough to handle the problem of detecting objects as a shape covering of a foreground mask, and to handle the problem of filtering confidence weighted detections produced by a traditional sliding window object detector. In our experiments, we show that our method outperforms two existing state-of-the-art pedestrian detectors.
Ultrarapid Purification of Collagen Type I for Tissue Engineering Applications

Acid-solubilized collagen type I (COL1) can form highly organized, three-dimensional scaffolds for a wide variety of bioengineering and cell culture applications. A rapid COL1 isolation method would be a valuable tool for both basic and translational researchers because conventional techniques require days or weeks to complete, typically use nonhuman animal tissues as a source material, and do not efficiently purify autologous COL1 from small samples. Here, we describe a 3-h method to isolate COL1 from rabbit, lamb, and human skin in sufficient quantities for fabrication of autologously derived tissues by using a rapid agitation technique and incorporating centrifugal filtration units into a traditional isolation procedure. We demonstrate that the purified product is comparable to traditional preparations using polyacrylamide gel electrophoresis, transmission electron microscopy, and collagen content assays. In addition, our COL1 is able to support myogenic cell growth and direct orientation of these cells in vitro. Importantly, this ultrarapid COL1 isolation procedure increases the feasibility of autologous COL1 use in humans as well as overall safety for clinical patients.
High-18O granitic plutons from the Frontenac Axis, Grenville province of ontario, Canada

Abstract 18 O 16 O ratios have been determined for whole rock as well as coexisting minerals from nine syn- to post-tectonic monzonite and quartz monzonite plutons in the Westport-Gananoque area covering approximately 2500 km2. The plutons fall in two distinct isotopic groups: 1. (I) Low-18O group (δ = 8.0–11.2): Rideau Lake, Westport and Wolfe Lake plutons and 2. (II) High-18O group (δ = 12.7–16.2): Lyndhurst, Perth Road, Battersea, Gananoque, South Lake and Crow Lake plutons. The 18 O 16 O ratios of granitic rocks from the latter group are among the highest ever reported in the literature. The isotopic compositions of samples within each pluton bear no relationship to the sample distance from the intrusive contacts nor are they affected by the types of country rocks (marbles vs. pelitic gneisses) into which they are emplaced. Oxygen isotope fractionations among coexisting quartz, feldspar, biotite and magnetite all show normal plutonic values. Thus, all lines of evidence suggest that the monzonite and quartz monzonite plutons did not acquire their characteristic 18 O 16 O ratios at the present level of exposure, either by isotopic exchange with the surrounding metasedimentary country rocks or by any post-crystallization low-temperature alteration processes. The distinct 18O/16O ratios observed in the high- and low-18O groups probably reflect the difference in the isotopic compositions of the source materials. The most plausible source for the high-18O group plutons is the Grenville Supergroup metasedimentary rocks and that for the low-18O group plutons the Grenville basement gneisses mixed with a small amount of Grenville Supergroup metasedimentary rocks.
Emerging methods for the study of coastal ecosystem landscape structure and change

Coastal landscapes are heterogeneous, dynamic, and evolve over a range of time scales due to intertwined climatic, geologic, hydrologic, biologic, and meteorological processes, and are also heavily...
Photochemically induced reactions of decacarbonyldimanganese(0)

Abstract Photolysis at ca. 350 nm of Mn 2 (CO) 10 in the presence of each of I 2 , CH 3 I, SnI 4 , CuCl 2 - 2 H 2 O, HgX 2 (X  Cl, Br or I), C 6 H 5 HgI, η 5 -C 5 H 5 Cr(NO) 2 Cl, (η 5 -C 5 H 5 ) 2 Cr 2 (NO) 4 and [Co 2 (CNCH 3 ) 10 ](BF 4 ) 4 , generally under N 2 or CO in several organic solvents (mainly cyclohexane and THF), was investigated. The observed photoreactions are best rationalized in terms of initial homolytic cleavage of the MnMn bond. In the presence of a halogen (X)-containing compound, the resultant Mn(CO) 5 · radical abstracts X to yield Mn(CO) 5 X. These reactions are characterized by high quantum efficiencies (generally, φ-Mn 2 (CO) 10 ⪆0.36). Following the abstraction, the remaining metal-containing species (usually a radical), SnCl 3 ·, CuCl, HgX·, C 6 H 5 Hg· or η 5 -C 5 H 5 Cr(NO) 2 ·, undergoes further abstraction of halogen by Mn(CO) 5 ·, coupling with the Mn(CO) 5 · or ligand substitution. Isolated metal-containing products include SnI 2 , Cu, Mn(CO) 5 HgX, Hg, [Mn(CO) 5 ] 2 Hg and η 5 -C 5 H 5 Cr(CO) 2 NO. Photolysis of Mn 2 (CO) 10 in the presence of each of the metal-metal bonded compounds, (η 5 -C 5 H 5 ) 2 Cr 2 (NO) 4 and [Co 2 (CNCH 3 ) 10 ](BF 4 ) 4 , does not give the respective heterodinuclear combinations, (η 5 -C 5 H 5 )(NO) 2 CrMn(CO) 5 and [(CH 3 NC) 5 CoMn(CO) 5 ] 2+ , as detectable or isolable species; instead, η 5 -C 5 H 5 Cr(CO) 2 NO, Mn(CO) 4 NO, Mn 2 (CO) 9 CNCH 3 , and [Mn(CO)(CNCH 3 ) 5 ] + are among the isolated products. The photoreaction between Mn 2 (CO) 10 and CH 3 I provides a convenient synthesis of Mn(CO) 5 I.
A New Rett Syndrome Family Consistent with X-Linked Inheritance Expands the X Chromosome Exclusion Map

Although familial recurrences of Rett syndrome (RTT) comprise only approximately 1% of the reported cases, it is these cases that hold the key for the understanding of the genetic basis of the disorder. Families in which RTT occurs in mother and daughter, aunt and niece, and half sisters are consistent with dominant inheritance and variable expressivity of the phenotype. Recurrence of RTT in sisters is likely due to germ-line mosaicism in one of the parents, rather than to recessive inheritance. The exclusive occurrence of classic RTT in females led to the hypothesis that it is X-linked and may be lethal in males. In an X-linked dominant disorder, unaffected obligate-carrier females would be expected to show nonrandom or skewed inactivation of the X chromosome bearing the mutant allele. We investigated the X chromosome inactivation (XCI) patterns in the female members of a newly identified family with recurrence of RTT in a maternal aunt and a niece. Skewing of XCI is present in the obligate carrier in this family, supporting the hypothesis that RTT is an X-linked disorder. However, evaluation of the XCI pattern in the mother of affected half sisters shows random XCI, suggesting germ-line mosaicism as the cause of repeated transmission in this family. To determine which regions of the X chromosome were inherited concordantly/discordantly by the probands, we genotyped the individuals in the aunt-niece family and two previously reported pairs of half sisters. These combined exclusion-mapping data allow us to exclude the RTT locus from the interval between DXS1053 in Xp22.2 and DXS1222 in Xq22.3. This represents an extension of the previous exclusion map.
In vitro and in vivo demonstration of physically and chemically in situ gelling NIPAAm-based copolymer system

Poly(NIPAAm-co-hydroxyethylmethacarylate (HEMA)) acrylate and poly(NIPAAm-co-cysteine ethyl ester (CysOEt)) were synthesized and characterized by GPC(gel permeation chromatography), rheology, NMR (nuclear magnetic resonance), and Ellman’s method. Upon mixing of these materials in aqueous solution, they formed gels immediately at body temperature owing to temperature-driven physical gelling, and gradually cured by chemical cross-linking through Michael-type addition reactions between thiols and acrylates. The rate of nucleophilic attack in the Michael-type addition reaction was shown to be highly dependent on the mole ratio of thiol to acrylate at neutral pH. Physical and chemical gelation improved the mechanical properties of the materials compared to purely physical gels. In vitro and in vivo results revealed that chemical and physical gels formed stiffer less viscoelastic materials compared to purely physical gels. Physical and chemical gel systems using thermosensitive polymer with acrylates and thermo...
Welfare Reform: Assessing its Political, Economic, and Social Effects

Books reviewed: Rebecca M. Blank, It Takes a Nation: A New Agenda for Fighting Poverty Anne Marie Cammisa, From Rhetoric to Reform?: Welfare Policy in AmericanPolitics Martha Shirk, Neil G. Bennett, and J. Lawrence Aber, Lives on the Line: American Families and the Struggle to Make Ends Meet Robert M. Solow, Work and Welfare
CHARACTERIZATION OF AN IN VITRO SYSTEM OF HUMAN RENAL PAPILLARY COLLECTING DUCT CELLS

We have developed an in vitro model of human papillary collecting duct cells isolated from cadaver kidneys using methods similar to those we previously reported for the isolation of human proximal tubule cells. To date we have isolated papillary collecting duct cells from 100 normal human kidneys. Papillae were dissected and digested in Cellgro containing 400 U/ml collagenase. Cells were plated on fibronectin-coated culture flasks at a density of 104 live cells/ml in Cellgro supplemented with insulin and 10% fetal bovine serum. Confluent monolayers, which were able to withstand 600 mOsm for 8 h, were obtained within 10 to 15 d. Cells of primary isolates and first passages exhibited epithelial cell ultrastructure including cell junctions, microvilli, and cilia. A dark-brown reaction product was observed in these cells when stained by the immunoperoxidase method with peroxidase-labeled peanut lectin (Arachis hypogaea), which binds specifically to human distal tubule and collecting duct cells. These cells were negative for Factor-VIII (a marker for endothelial cells) and γ-glutamyltransferase (a marker for proximal tubule cells). High activities of the glycolytic enzyme pyruvate kinase and arginine vasopressin-stimulated cAMP production in these cells are consistent with a distal nephron origin. The results indicate that human collecting duct cells can be isolated and cultured to provide an in vitro system to probe pathogenetic mechanisms of potential nephrotoxins.
Mechanism of CaM Kinase IV Activation During Hypoxia in Neuronal Nuclei of the Cerebral Cortex of Newborn Piglets: The Role of Src Kinase

The present study aims to investigate the mechanism of CaM kinase IV activation during hypoxia and tests the hypothesis that hypoxia-induced increased activity of CaM kinase IV is due to Src kinase mediated increased tyrosine phosphorylation of calmodulin and CaM kinase IV in neuronal nuclei of the cerebral cortex of newborn piglets. Piglets were divided into normoxic (Nx, n = 5), hypoxic (Hx, FiO2 of 0.07 for 1 h, n = 5) and hypoxic-pretreated with Src kinase inhibitor PP2 (Hx-Srci, n = 5) groups. Src inhibitor was administered (1.0 mg/kg, I.V.) 30 min prior to hypoxia. Neuronal nuclei were isolated and purified, and tyrosine phosphorylation of calmodulin (Tyr99) and CaM kinase IV determined by Western blot using anti-phospho-(pTyr99)-calmodulin, anti-pTyrosine and anti-CaM kinase IV antibodies. The activity of CaM kinase IV and its consequence the phosphorylation of CREB protein at Ser133 were determined. Hypoxia resulted in increased tyrosine phosphorylation of calmodulin at Tyr99, tyrosine phosphorylation of CaM kinase IV, activity of CaM kinase IV and phosphorylation of CREB protein at Ser133. The data show that administration of Src kinase inhibitor PP2 prevented the hypoxia-induced increased tyrosine phosphorylation of calmodulin (Tyr99) and tyrosine phosphorylation of CaM.kinase IV as well as the activity of CaM kinase IV and CREB phosphorylation at Ser133. We conclude that the mechanism of hypoxia-induced increased activation of CaM kinase IV is mediated by Src kinase-dependent tyrosine phosphorylation of the enzyme and its activator calmodulin. We propose that Tyr99 phosphorylated calmodulin, as compared to non-phosphorylated, binds with a higher affinity at the calmodulin binding site (rich in basic amino acids) of CaM kinase IV leading to increased activation of CaM kinase IV. Similarly, tyrosine phosphorylated CaM kinase IV binds its substrate with a higher affinity and thus increased tyrosine phosphorylation leads to increased activation of CaM kinase IV resulting in increased CREB phosphorylation that triggers increased transcription of proapoptotic proteins that initiate hypoxic neuronal death.
Risk of Parkinson's disease among first-degree relatives: A community-based study

Objective: To determine the relative risk (RR) and cumulative incidence of idiopathic Parkinson9s disease (PD) in first-degree relatives of PD patients compared with relatives of controls from the same geographic region. Design: A family history questionnaire was used to obtain information on all first-degree relatives of cases and controls. A subset of these first-degree relatives was also examined. A Cox proportional hazards model with double-censoring techniques for missing information was used to model the RR for PD, adjusting for gender, ethnicity, and relationship to proband. Results: A total of 1,458 first-degree relatives of 233 PD patients were 2.3 times as likely (95% CI = 1.3 to 4.0) as 7,834 relatives of 1,172 controls to develop PD. The cumulative incidence of PD to age 75 among first-degree relatives of PD patients was 2% compared with 1% among first-degree relatives of controls. The risk in male first-degree relatives was higher than in female relatives (RR = 2.0, 95% CI = 1.1 to 3.4) and the risk in relatives of Caucasians was higher than in African-Americans and Hispanics (RR = 2.4, 95% CI = 1.4 to 4.1). Risk for siblings and parents of probands was similar. Conclusions: Susceptibility to PD is increased in first-degree relatives of both sporadic and familial cases. The pattern of inheritance and the relationship between genetic and environmental risk factors warrant further study. NEUROLOGY 1996;47: 155-160
Nonlinear transverse modes of large-aspect-ratio homogeneously broadened lasers: I. Analysis and numerical simulation.

Transverse pattern evolution is investigated in single-longitudinal-mode two-level and Raman lasers with flat end reflectors, subjected to uniform transverse pumping. The natural nonlinear modes of the laser are identified as spatially homogeneous when the detuning from the gain peak is negative and as ``local'' plane traveling waves when the detuning is positive. The latter correspond to an off-axis emission of the laser. Stability characteristics of the underlying patterns are predicted to be quite different for one-dimensional and two-dimensional (2D) lasers. As an illustration, we provide direct numerical evidence for weakly turbulent behavior of a 2D Raman laser where Eckhaus and zigzag phase instabilities act in concert to spontaneously nucleate topological defects and ridgelike illuminated regions. Our numerics also confirm that the complicated patterns persist for finite transverse pumping as long as the characteristic width of the pump source contains a sufficient number of selected pattern wavelengths.
Low-energy limits of theories with two supersymmetries

Given its non-renormalization properties, low-energy supersymmetry provides an attractive framework for extending the standard model and for resolving the hierarchy problem. Models with softly broken $N=1$ supersymmetry have been extensively studied and are phenomenologically successful. However, it could be that an extended $N=2$ supersymmetry survives to low energies, as suggested by various constructions. We examine the phenomenological viability and implications of such a scenario. We show that consistent chiral fermion mass generation emerges in $N=2$ theories, which are vectorial, as a result of supersymmetry breaking at low energies. A rich mirror quark and lepton spectrum near the weak scale with model-dependent decay modes is predicted. A ${Z}_{2}$ mirror parity is shown to play an important role in determining the phenomenology of the models. It leads, if conserved, to a new stable particle, the LMP. Consistency of the $N=2$ framework and its unique spectrum with electroweak precision data is considered, and the discovery potential in the next generation of hadron collider experiments is stressed. Mirror quark pair production provides the most promising discovery channel. Higgs boson searches are also discussed and it is shown that there is no upper bound on the prediction for the Higgs boson mass in the framework of low-energy supersymmetry breaking, in general, and in the $N=2$ framework, in particular. Possible $N=2$ realizations of flavor symmetries and of neutrino masses are also discussed.
The conceptual commonality between impulsiveness as a personality trait and as an ego development stage

Abstract This research was an attempt to demonstrate the conceptual commonality between impulsiveness as a trait and as an ego development stage through correlations on measures of both. An Eysenckian measure of broad trait impulsiveness (Imp B ) consisting of four impulsiveness subscales, the Eysenck Personality Questionnaire (EPQ) and the Washington University Sentence Completion Test (WUSCT) of ego development were administered to 62 male students and 101 female students distributed across three different educational levels (Junior High, Senior High and College). Significant correlations between Imp B and the WUSCT (-0.23 for the males and -0.31 for the females) supported the hypothesized commonality. Correlations between the WUSCT and the four impulsiveness subscales indicated that Narrow Impulsiveness and Risk-taking were more indicative of ego development than Non-planning or Liveliness. Age trends in the patterns of correlations demonstrated that the commonality between trait impulsiveness and ego development was limited to the early stages of ego development. Sex differences on a number of trait measures and on the WUSCT indicated that males lag behind females in ego development during adolescence. It was hypothesized that the aspect of impulsiveness most indicative of ego development was an unsocialized aspect which might be captured by Eysenck's dimension of psychoticism (P). Correlations between P and WUSCT supported this hypothesis (-0.49 for the males and -0.29 for the females). P apparently has more concept commonality with ego development than has trait impulsiveness. Age trends and sex differences in impulsiveness, psychoticism, and aggressiveness were discussed. It was argued that these personality characteristics would be better understood if explored within a developmental framework such as ego development.
Interstitial pneumonitis in the immunologically suppressed child: an urgent surgical condition

Thirty-eight children were evaluated for interstitial pneumonia by open lung biopsy. In most instances the patients were immunosuppressed as a result of cancer chemotherapy and irradiation. Pneumocystis carinii infection was the most common cause of pneumonitis (60.4%), especially in children with leukemia (78.3%). The clinical triad of hypoxemia, tachypnea, and a diffuse interstitial infiltrate on chest x-ray, is an indication for early open lung biopsy. Survival was 91.7% in cases of acute pneumocystis pneumonia, a significant improvement over previous reports. These observations strongly support the concept of early open lung biopsy in the management of diffuse interstitial pneumonitis in patients who are immunosuppressed.
Transcription Factor NF-κB Is Necessary for Up-regulation of Type 1 Angiotensin II Receptor mRNA in Rat Cardiac Fibroblasts Treated with Tumor Necrosis Factor-α or Interleukin-1β

Abstract Tumor necrosis factor-α (TNF-α) and interleukin-1β up-regulate type 1 angiotensin II receptor (AT1) mRNA and protein in cultured neonatal rat cardiac fibroblasts. The use of pharmacologic inhibitors and a degradation-resistant mutant IκB-α demonstrated that the transcription factor nuclear factor-κB (NF-κB) is necessary for cytokine-induced AT1 up-regulation. The increase in AT1 mRNA with TNF-α treatment is slow, reaching significance by 6–12 h and peaking by 24–48 h. Electrophoretic mobility shift assays revealed that NF-κB nuclear translocation was maintained for ≥24 h with a single dose of TNF-α. Since prolonged NF-κB activation appeared necessary to maximize AT1up-regulation, the mechanism of persistent NF-κB activation was studied further. Stimulation with TNF-α induced a >10× increase in IκB kinase (IKK) activity that quickly diminished by 20 min. IκB-α and IκB-β proteins were degraded during this time, and IκB-α was resynthesized subsequently by NF-κB-dependent transcription. However, IκB isoforms and IKK activity did not return completely to unstimulated values during a 12-h time course. These results suggest that low but persistent IKK activity and IκB degradation lead to prolonged NF-κB nuclear translocation and maximal AT1 up-regulation in the continued presence of TNF-α.
Assessment of Visual Analog versus Categorical Scale for Measurement of Osteoarthritis Pain

There is disagreement in the literature regarding which scales to use in pain measurement. The difference has usually been between nonverbal scales, such as visual analog scales and verbal ones, which usually provide only a limited number of response categories. A 12-week, randomized, double-blind naproxen sodium (500 mg bid) and placebo-controlled trial using the hip osteoarthritis (OA) flare-up pain mode, in which pain was measured on both visual analog and categorical scales simultaneously, was analyzed. The authors found a good correlation (> 0.995) between the time-series average of the unconstrained visual analog scale and a 5-point categorical scale pain measurement in the osteoarthritis pain model in both active and placebo treatment arms. However, for individuals, there is a wide range of VAS responses for each categorical score, with overlaps between categories. The visual analog and categorical scales appear as effective in determining average osteoarthritis pain. However, a combined metric scale for pain measurement that provides the subject with multiple cues may improve communication and concordance between scales for individual pain determination.
BRAF mutation in papillary thyroid cancer: pathogenic role, molecular bases, and clinical implications.

In recent years, the T1799A B-type Raf kinase (BRAF) mutation in thyroid cancer has received enthusiastic investigation, and significant progress has been made toward understanding its tumorigenic role and clinical significance. Among various thyroid tumors, this mutation occurs uniquely in papillary thyroid cancer (PTC), the most common endocrine malignancy, and some apparently PTC-derived anaplastic thyroid cancers. Many studies have found this mutation to be associated with those clinicopathological characteristics of PTC that are conventionally known to predict tumor progression and recurrence, including, for example, old patient age, extrathyroidal invasion, lymph node metastasis, and advanced tumor stages. Direct association of BRAF mutation with the clinical progression, recurrence, and treatment failure of PTC has also been demonstrated. The BRAF mutation has even been correlated with PTC recurrence in patients with conventionally low-risk clinicopathological factors. Some molecular mechanisms det...
A Dynamic Range Compression and Three-Dimensional Peptide Fractionation Analysis Platform Expands Proteome Coverage and the Diagnostic Potential of Whole Saliva

Comprehensive identification of proteins in whole human saliva is critical for appreciating its full diagnostic potential. However, this is challenged by the large dynamic range of protein abundance within the fluid. To address this problem, we used an analysis platform that coupled hexapeptide libraries for dynamic range compression (DRC) with three-dimensional (3D) peptide fractionation. Our approach identified 2340 proteins in whole saliva and represents the largest saliva proteomic dataset generated using a single analysis platform. Three-dimensional peptide fractionation involving sequential steps of preparative isoelectric focusing (IEF), strong cation exchange, and capillary reversed-phase liquid chromatography was essential for maximizing gains from DRC. Compared to saliva not treated with hexapeptide libraries, DRC substantially increased identified proteins across physicochemical and functional categories. Approximately 20% of total salivary proteins are also seen in plasma, and proteins in both fluids show comparable functional diversity and disease-linkage. However, for a subset of diseases, saliva has higher apparent diagnostic potential. These results expand the potential for whole saliva in health monitoring/diagnostics and provide a general platform for improving proteomic coverage of complex biological samples.