cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular evidence for a single genetic clone of invasive Arundo donax in the United States

Arundo donax (giant reed) is an aggressive invasive weed of riparian habitats throughout the southern half of the United States from California to Maryland. Native to Asia, the species is believed to have been initially introduced into North America from the Mediterranean region although subsequent introductions were from multiple regions. To provide insight into the potential for biological control of A. donax, genetic variation in plants sampled from a wide geographical area in the United States was analyzed using Sequence Related Amplification Polymorphism (SRAP) and transposable element (TE)-based molecular markers. Invasive individuals from 15 states as well as four populations in southern France were genetically fingerprinted using 10 SRAP and 12 TE-based primer combinations. With the exception of simple mutations detected in four plants, A. donax exhibited a single multilocus DNA fingerprint indicating a single genetic clone. The genetic uniformity of invasive A. donax suggests that classical biological control of the species could be successful. A lack of genetic diversity in the invaded range simplifies identification of native source populations to search for natural enemies that could be used as biocontrol agents.
NEW OPTIMIZATION MODELS FOR DATA MINING

In recent years modern methods of optimization have contributed greatly to the advances in data mining and related areas. These contributions continue today and promise to further advance the state of the art both in terms of modeling innovations and new solution methodologies. In this paper, we present a new modeling and solution methodology for unsupervised clustering. Preliminary computational experience is given to illustrate the approach. This methodology is part of our current research and offers considerable opportunity for additional investigation to be conducted by other researchers.
Scaling study of graphene transistors

By performing rigorous self-consistent atomistic quantum transport simulations, scaling behavior of graphene-based MOSFET and TFET are investigated. We show that phonon scattering can negatively affect the on-current and transconductance of a MOSFET significantly, and therefore on-state characteristics can be improved by reducing the channel length down to 30 nm. For a TFET, however, off-state characteristics are very susceptible to phonon scattering, and off-current can increase by 6 orders of magnitude in a 30-nm-channel TFET. In contrast to what is predicted in the ballistic picture, the minimum leakage current and subthreshold swing of a TFET do not monotonically decreased by increasing channel length, but saturate for a channel length longer than 20 nm.
Solute Effects on β-Sn Grain Boundary Energy and Shear Stress

The excess enthalpy and shear strain behavior of the β-Sn (101) grain boundary containing various amounts of Ag and Cu solute atoms was investigated using molecular simulation. An increase in either type of solute at the interface lowers the excess enthalpy of the grain boundary. The enthalpies of segregation for both solute types are computed as the slope of excess enthalpy of the grain boundary per area versus interfacial solute concentration per area. For Ag, ΔHSEG=0.64(9) eV/atom , and for Cu, ΔHSEG=0.45(8) eV/atom , indicating a preference for grain boundary segregation. These results agree with other simulation work that attributes a larger decrease in grain boundary energy to a solute with a larger atomic radius. A (301) special boundary of β-Sn was also investigated and found ΔHSEG=0.12(9) eV/atom for Ag and ΔHSEG=0.06(9) eV/atom for Cu. Statistically, this shows the possibility for excess enthalpy increase when Cu is present at the (301) boundary. Under constant shear strain, addition of solu...
Assessing minimum viable population size: Demography meets population genetics

The discussion of a population's minimum viable size provides a focus for the study of ecological and genetic factors that influence the persistence of a threatened population. There are many causes of extinction and the fate of a specific population cannot generally be predicted. This uncertainty has been dealt with in two ways: through stochastic demographic models to determine how to minimize extinction probabilities; and through population genetic theory to determine how best to maintain genetic variation, in the belief that the ability to evolve helps buffer a population against the unknown. Recent work suggests that these two very different approaches lead to very similar conclusions, at least under panmictic conditions. However, defining the ideal spatial distribution for an endangered species remains an important challenge.
Population patterns of Aspergillus flavus group and A. niger group in field soils

Abstract The horizontal distribution of soil-borne fungi in field soils is an important component of fungal ecology. Aspergillus flavus group and its antagonist, the A. niger group, had moderate and moderate to high degrees of aggregation (patchiness), respectively, in two peanut fields with a history of aflatoxin contamination: Lloyd's index of patchiness values ranged from 2.32 to 6.55, where 1.0 is a random pattern. For the A. niger group, there was evidence that quadrats in close proximity had similar population densities. Clump size, rarely reported for soil-borne fungi, was found to be 13–52 m 2 for A. niger group in one field. Mean population densities of A. flavus group in both fields were higher than found previously in most Virginia peanut fields and, along with moderate aggregation, may be related, in part, to the occurrence of aflatoxin in these fields.
An interdisciplinary reading of Chicana/o and (US) Central American cross-cultural narrations

How do Mexican Americans and US Central Americans textually represent (US) Central American, Chicana/o and Mexican American subjects and what can be gained or lost by these intercultural narrations? Issues of naming, generalizing and anxieties of transculturation in Chicana/o and US Central American narratives are developed especially in the access and deployment of US Central American voice and authorial agency. Through mutual (mis)representations, both US Central Americans and Chicana/os open textual spaces where US Central Americans now more fully represent themselves as they question their own Chicana/o, Central American and American identifications. The article explores these textual intercultural (mis)representations and seeks to contribute to the emergent body of knowledge by US Central Americans whose relevance continues to grow within Chicana/o and Latina/o literatures and discourses.
Reducible poly(2-dimethylaminoethyl methacrylate): Synthesis, cytotoxicity, and gene delivery activity

Reducible polycations represent promising carriers of therapeutic nucleic acids. Oligomers of 2-dimethylaminoethyl methacrylate (DMAEMA) containing terminal thiol groups were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using difunctional chain transfer agent. Reducible poly(DMAEMA) (rPDMAEMA) was synthesized by oxidation of the terminal thiol groups, forming a polymer with disulfide bonds in the backbone. Physico-chemical properties of DNA polyplexes of rPDMAEMA were evaluated by dynamic and static light scattering methods, revealing lower structural density and DNA content than control PDMAEMA polyplexes. Cytotoxicity and transfection activity of rPDMAEMA-based DNA polyplexes were evaluated in vitro. In comparison with control PDMAEMA, only minimum toxic effects of rPDMAEMA were observed in a panel of cell lines. Transfection activity was tested in B16F10 mouse melanoma and six human pancreatic cancer cell lines. rPDMAEMA polyplexes showed a comparable or better activity than control PDMAEMA polyplexes.
Utility guy wires - a potential electrical hazard

Electrocutions can occur in low and medium voltage systems, when a person comes in direct contact with a conductor at a high voltage or when there is a conductive contaminant which creates an electrically conductive path across an insulating member.
Reduced expression of peptide-loaded HLA class I molecules on multiple sclerosis lymphocytes.

Lymphocytes from patients with HLA class II-linked autoimmune diseases such as type I diabetes, systemic lupus erythematosus, rheumatoid arthritis, and Graves' have recently been shown to have a decrease in the expression of self-peptide-filled HLA class I antigens on the surface of peripheral lymphocytes. The human demyelinating diseases of multiple sclerosis in some cases are also associated with the presence of certain HLA class II genes, which may in turn be linked to genes in the class II region that control class I expression. Hence, we studied fresh peripheral blood mononuclear cells (PBMCs) and newly produced Epstein-Barr virus (EBV)-transformed cell lines from multiple sclerosis patients for the class I defect. Unseparated PBMCs, as well as T cells, B cells, and macrophages from multiple sclerosis patients had a decrease in the amount of conformationally correct peptide-filled HLA class I molecules on the cell surface compared with matched controls detectable by flow cytometry. To demonstrate the independence of this defect from exogenous serum factors, newly produced EBV-transformed cell lines from B cells of patients with multiple sclerosis maintained the defect. In addition, DR2 +/+, +/-, and -/- EBV-transformed B cells from these patients similarly demonstrated the self-antigen presentation defect. Analysis of a set of discordant multiple sclerosis twins revealed the class I defect was exclusively found on the affected twin lymphocytes, suggesting a role of this class I complex in disease expression. These data indicate that multiple sclerosis patients have abnormal presentation of self-antigens. This phenomenon, common to a number of HLA-linked autoimmune disorders, may be associated with failed self-tolerance and improper T-cell education secondary to faulty HLA class I assembly controlled by HLA class II linked genes.
Enhancement in ballistic performance of composite hard armor through carbon nanotubes

The use of carbon nanotubes in composite hard armor is discussed in this study. The processing techniques to make various armor composite panels consisting of Kevlar®29 woven fabric in an epoxy matrix and the subsequent V50 test results for both 44 caliber soft-point rounds and 30 caliber FSP (fragment simulated projectile) threats are presented. A 6.5% improvement in the V50 test results was found for a combination of 1.65 wt% loading of carbon nanotubes and 1.65 wt% loading of milled fibers. The failure mechanism of carbon nanotubes during the ballistic event is discussed through scanning electron microscope images of the panels after the failure. Raman Spectroscopy was also utilized to evaluate the residual strain in the Kevlar®29 fibers post shoot. The Raman Spectroscopy shows a Raman shift of 25 cm−1 for the Kevlar®29 fiber utilized in the composite panel that had an enhancement in the V50 performance by using milled fiber and multi-walled carbon nanotubes. Evaluating both scenarios where an improvem...
Constrained multifidelity optimization using model calibration

Multifidelity optimization approaches seek to bring higher-fidelity analyses earlier into the design process by using performance estimates from lower-fidelity models to accelerate convergence towards the optimum of a high-fidelity design problem. Current multifidelity optimization methods generally fall into two broad categories: provably convergent methods that use either the high-fidelity gradient or a high-fidelity pattern-search, and heuristic model calibration approaches, such as interpolating high-fidelity data or adding a Kriging error model to a lower-fidelity function. This paper presents a multifidelity optimization method that bridges these two ideas; our method iteratively calibrates lower-fidelity information to the high-fidelity function in order to find an optimum of the high-fidelity design problem. The algorithm developed minimizes a high-fidelity objective function subject to a high-fidelity constraint and other simple constraints. The algorithm never computes the gradient of a high-fidelity function; however, it achieves first-order optimality using sensitivity information from the calibrated low-fidelity models, which are constructed to have negligible error in a neighborhood around the solution. The method is demonstrated for aerodynamic shape optimization and shows at least an 80% reduction in the number of high-fidelity analyses compared other single-fidelity derivative-free and sequential quadratic programming methods. The method uses approximately the same number of high-fidelity analyses as a multifidelity trust-region algorithm that estimates the high-fidelity gradient using finite differences.
Developmental consequences of mutations in the 84B α-tubulin gene of Drosophila melanogaster

Abstract Developmental effects of six mutations in the gene encoding the majority of α-tubulin in all tissues at all stages of Drosophila melanogaster development have been examined. All six alleles produce at least partially stable α84B protein. In genetic assays, two of these alleles approximate the null condition. The other four alleles appear to form a graded series of hypomorphs. The two most severe alleles produce a semidominant maternal-effect polyphasic lethality, plus a predominantly larval recessive zygotic lethality. Clonal analysis of one of these alleles suggests it is a cell lethal. Worsening of the lethal phenotype (negative complementation) occurs in most interallelic heterozygotes involving these two mutations. As hemizygotes, the other four alleles are predominantly larval/pupal lethals. Partial complementation is achieved by most interallelic heterozygotes involving these four alleles. Phenotypic defects associated with the six tubulin mutations include disrupted embryos, pseudopupae, pharate adults with defects in various cuticular pattern elements, pharate adults with retarded head development, adults with leg tremors and extremely short life spans, and viable but sterile adults with bristle defects.
Follicular Lymphoma with Marginal Zone Differentiation: Microdissection Demonstrates the t(14;18) in Both the Follicular and Marginal Zone Components

On occasion, follicle center lymphomas (FCL) may contain a marginal-zone (MZ) component in which the interfollicular lymphoid cells take on an MZ cell morphology. In the past, these have been termed composite lymphomas. However, recent studies suggest that the two components are clonally related. It is unknown whether the bcl-2 translocation present in most FCLs is present in the cells that demonstrate MZ cell morphology. We have identified three cases of low-grade FCL with a MZ component suitable for laser capture microdissection (LCM) of the two components. Cases were immunophenotyped in paraffin section with antibodies to CD10, CD20, bcl-2, and bcl-6. LCM was done to isolate cells from each component. Polymerase chain reaction for t(14;18) using primers to the major breakpoint region was performed on DNA extracts. The sensitivity of the PCR assay was decreased to 5%--10% follicle center cells in a background of reactive tonsil cells. All three cases showed different phenotypes in each component. The FCL component was positive for all four of the above markers, whereas the MZ component expressed only CD20 and bcl-2. Both components showed t(14;18) amplicons of identical size, with the MZ component signal being stronger than the 5%--10% sensitivity control, suggesting that the signal was not from rare, contaminating FCL cells. These results confirm that both components are clonally related and support the theory that these are indeed FCLs with MZ differentiation (that retain the t(14;18)) rather than the reverse, MZ lymphoma with follicle center differentiation.
Electron attachment to oxygen and other solutes in non-polar liquids

Abstract The rates of electron attachment to oxygen and other solutes are reported as a function of temperature for several high-electron-mobility liquids. Whereas the reaction with perfluorocyclobutane is fast in all solvents, that with oxygen is considerably slower. For both reactions the rates are energy dependent and are influenced by the energy (V0) of the conduction band of the solvent as well as by the polarization energy (P−) of the product anion. The activation energies can be accounted for in terms of changes in these energies.
An assumed stress hybrid finite element method for an incompressible and near-incompressible material☆

Abstract A variational principle based on assumed stress hybrid method suitable for incompressible or nearincompressible solid is formulated for finite element analysis. One example to illustrate the use of the method is given.
SMISB: A system for Managing Minimum Information from omics' studies in systems biology

Because biological systems with high-throughput performance generate huge amount of experimental data, biologists need efficient methods to analyze large datasets. Specifically, researchers in systems biology require the ability to compare and integrate complex data from different omics' experiments. This requirement results in the standardization of formats for data representation and communication. These standards can be categorized into three parts: reporting, data exchange and modeling, and terminology. Even though these standards are very helpful for analyzing data in each omics' experiment, we need to integrate them into unified standardized format for studies of systems biology because most researchers in systems biology require cross-omics' studies. To satisfy these requirements, we developed the object model for SMISB (System of Managing Minimum Information in Systems Biology). This model accommodates reporting, exchange, and management of data from five different omics such as genomics, epigenomics, transcriptomics, proteomics, and metabolomics.
Effect of temperature and CO2 concentration on laser-induced breakdown spectroscopy measurements of alkali fume

Abstract Laser-induced breakdown spectroscopy (LIBS) was used in the evaluation of aerosol concentration in the exhaust of an oxygen/natural-gas glass furnace. Experiments showed that for a delay time of 10 μs and a gate width of 50 μs, the presence of CO 2 and changes in gas temperature affect the intensity of both continuum emission and the Na D lines. The intensity increased for the neutral Ca and Mg lines in the presence of 21% CO 2 when compared to 100% N 2 , whereas the intensity of the Mg and Ca ionic lines decreased. An increase in temperature from 300 to 730 K produced an increase in both continuum emission and Na signal. These laboratory measurements were consistent with measurements in the glass furnace exhaust. Time-resolved analysis of the spark radiation suggested that differences in continuum radiation resulting from changes in bath composition are only apparent at long delay times. The changes in the intensity of ionic and neutral lines in the presence of CO 2 are believed to result from higher free electron number density caused by lower ionization energies of species formed during the spark decay process in the presence of CO 2 . For the high Na concentration observed in the glass furnace exhaust, self-absorption of the spark radiation occurred. Power law regression was used to fit laboratory Na LIBS calibration data for sodium loadings, gas temperatures, and a CO 2 content representative of the furnace exhaust. Improvement of the LIBS measurement in this environment may be possible by evaluation of Na lines with weaker emission and through the use of shorter gate delay times.
The syntheses of 3-substituted perfluoroalkyl steroids

Abstract The syntheses of three classes of C-3 perfluoroalkyl substituted steroids are described. They are the 3β-hydroxy-3α-perfluoroalkylandrost-4-en-17-ones ( 5a-c ), 3-perfluoroalkylandrosta-3,5-dien-3-ones ( 8a-c ) and 3β-hydroxy-3α-perfluoroalkylandrost-5-en-17-ones ( 12a-c ). Addition of a series of perfluroalkylorganometallic reagents (R F Li; R F = C 2 F 5 , C 3 F 7 , or C 4 F 9 ) to the 3 position of silylated testosterone 2b afforded Δ 4 perfluoroalkyl carbinols 3. In Scheme 1, deprotection with HF and oxidation at the C-17 carbon with PCC produced Δ 4 ketones 5. In Scheme 2 dehydration of 3 with 1,2-phenylenephosphorochloridite and iodine afforded Δ 3,5 dienes 6 which were deprotected and oxidized as above to the C-17 ketones 8. In Scheme 3 isomerization of the double bond of 3 from the C-4 to the C-5 position using the allylic halogenation followed by treatment with lithium aluminum hydride led to the synthesis of the double bond isomer series 12. A new method for dehydration was developed. On average and within experimental error, 3β-hydroxy-3α-perfluoroalkylandrost-5-en-17 ones ( 12a-c ) were better than the 3-perfluoroalkylandrosta-3,5-dien-17-ones ( 8a-c ) and 3β-hydroxy-3α-perfluoroalkylandrost-4-en-17-ones ( 5a-c ) at inhibiting glucose-6-phosphate dehydrogenase.
Measuring grain-boundary segregation in nanocrystalline alloys: direct validation of statistical techniques using atom probe tomography

Atom probe tomography (APT) is used to investigate grain-boundary segregation of W solute atoms in nanocrystalline Ni. For the heat-treated specimens used here, the grain structure can be observed in the APT data, enabling direct composition analyses across individual grain boundaries. These direct measurements are used to validate methods proposed in earlier work, which determine the average segregation state in nanocrystalline materials through statistical analysis of the solute distribution, without knowledge of the boundary positions. Good agreement is demonstrated between the two experimental techniques.
Changes in fault displacement populations correlated to linkage between faults

In Carboniferous strata exposed at the western margin of the southern Appalachian (U.S.A.) fold—thrust belt, mesoscopic faults accommodated strains as the Cumberland Plateau thrust sheet moved ≤ 1 km WNW on a sub-horizontal detachment. These faults are confined to a layer ∼ 75 m thick above the detachment. In the upper part of this ∼ 75 m thick layer, a laterally persistent coal seam separates two stratigraphic units subjected to different amounts of sub-horizontal elongation. Distinct sets of mesoscopic faults that cut bedding at high angles and have normal offsets accommodate the strains in each unit. Below the coal seam, a sample line ∼ 500 m long intersects 504 faults. A plot of log N (size rank) vs log d (dip separation in mm) for these faults is linear, suggesting that a scaling law N = ad−c holds for this population. Least-squares regression gives c ≈ 0.8 and log10 a ≈ 3.1. Above the coal seam, a sample line ∼250 m long intersects 745 faults. A plot of log N vs log d for these faults has two distinct linear trends. Faults with separations ≤ 1.25 m yield a scaling law N = ad−c with c ≈ 0.5 and log10 a ≈ 2.9. Seventeen faults with separations d ≥ 1.25 m define a second linear segment N = a′ d−c′, with c′ ≈ 1.8 and log10 a′ ≈ 6.9. The break in slope at d ≈ 1.25 m corresponds to faults with heights of ∼30 m, roughly equal to the thickness of the faulted strata. Faults here with d ≤ 1.25 m and d ≥ 1.25 m, which exhibit different scaling characteristics, are, respectively, analogous to faults within and those that extend across the brittle crust in regional studies. Comparing the two displacement populations described here, small-offset faults make a proportionally smaller contribution to the total strain in the larger strain setting. This pattern, which is observed elsewhere, suggests that fault systems within individual layers exhibit different scaling characteristics at different stages in their history. This contribution argues that fault linkage is the key to such changes in fault scaling behavior; it is a mesoscopic to macroscopic structural change that alters the subsequent development of faults. Fault linkage, like fault size or sampling dimension, should be considered in examinations of fault scaling laws.
Gains in employment status following antidepressant medication or cognitive therapy for depression

Background Depression can adversely affect employment status. Aims To examine whether there is a relative advantage of cognitive therapy or antidepressant medication in improving employment status following treatment, using data from a previously reported trial. Method Random assignment to cognitive therapy ( n = 48) or the selective serotonin reuptake inhibitor paroxetine ( n = 93) for 4 months; treatment responders were followed for up to 24 months. Differential effects of treatment on employment status were examined. Results At the end of 28 months, cognitive therapy led to higher rates of full-time employment (88.9%) than did antidepressant medication among treatment responders (70.8%), χ21 = 5.78, P = 0.02, odds ratio (OR) = 5.66, 95% CI 1.16-27.69. In the shorter-term, the main effect of treatment on employment status was not significant following acute treatment (χ21 = 1.74, P = 0.19, OR = 1.77, 95% CI 0.75-4.17); however, we observed a site×treatment interaction (χ21 = 6.87, P = 0.009) whereby cognitive therapy led to a higher rate of full-time employment at one site but not at the other. Conclusions Cognitive therapy may produce greater improvements in employment v. medication, particularly over the longer term.
The phenomenon of blogs and theoretical model of blog use in educational contexts

Many educators have attempted to implement a blog in educational contexts to enhance the communication environment among students and teachers. However, it is uncertain as to why traditional computer-mediated communication (CMC) applications should be replaced with blogs. It is time to comprehensively explore the effects of educational blogs by considering the CMC tools. This paper reviews prior studies and develops a model for the use of blogs in educational contexts by taking into account socio-technical systems theory. The model contributes to interactivity, an open system, a visualization tool, and a decentralized environment of online communication circumstance.
Spatial and temporal evolution of dynamic damage in single crystal α-quartz

Abstract The quantitative measurement of the spatial and temporal evolution of dynamic damage from impact failure is necessary to provide understanding and accurately predict the overall dynamic mechanical behavior of brittle ceramics. This paper characterizes the spatial and temporal evolution of dynamic damage in synthetic single crystal quartz specimens used as a model material system. Single crystal x-cut α -quartz is impacted using a Kolsky (split-Hopkinson) bar in the [ 1 1 2 ¯ 0 ] and [ 1 0 1 ¯ 0 ] directions. The heterogeneity of the damage evolution presented provides insight into the failure processes, as well as benchmark data for computational simulations of dynamic failure. The results revealed a reduction in the rate of damage near peak loading, and dynamic failure was found to occur preferentially along the second order trigonal–pyramidal or ( 1 1 2 ¯ 2 ) plane. These findings are compared to an existing analytical micromechanical damage model and are discussed in terms of the crystalline anisotropy and general fracture mechanics theory.
Linear Calibration of Radiographic Mineral Density Using Video-Digitizing Methods

Radiographic images can provide quantitative as well as qualitative information if they are subjected to densitometric analysis. Using modern video-digitizing techniques, such densitometry can be readily accomplished using relatively inexpensive computer systems. However, such analyses are made more difficult by the fact that the density values read from the radiograph have a complex, nonlinear relationship to bone mineral content. This article derives the relationship between these variables from the nature of the intermediate physical processes, and presents a simple mathematical method for obtaining a linear calibration function using a step wedge or other standard.
The angry patient : An intervention for managing anger in substance abuse treatment

Patients who have problems controlling anger and aggression can pose special problems for substance abuse treatment providers. Levels of anger and violence are higher in substance abusers than in the general population. Although anger management treatments have been studied extensively, few treatments have been developed and studied with substance abusers. In this article, we evaluated an anger management treatment based on Novaco's (1983) cognitive-behavioral stress inoculation procedures. The treatment was delivered as individual sessions and evaluated in a study of six substance abuse patients with a single-subject multiple-baseline design. Preliminary findings suggest that the treatment is effective for substance abuse patients and that this mode of treatment should be explored further.
Preprocessed and postprocessed quantization index modulation methods for digital watermarking

Quantization index modulation (QIM) methods, a class of digital watermarking and information embedding methods, achieve very efficient trade-offs among the amount of embedded information (rate), the amount of embedding-induced distortion to the host signal, and the robustness to intentional and unintentional attacks. For example, we show that against independent additive Gaussian attacks, which are good models for at least some types of uniformed and unintentional attacks, QIM methods exist that achieve the best possible rate-distortion-robustness trade-offs (i.e., capacity) asymptotically at high rates and achieve performance within a few dB of capacity at all finite rates. Furthermore, low- complexity realizations of QIM methods, such as so-called dither modulation, have also been shown to achieve favorable rate-distortion-robustness trade-offs. We further develop preprocessing and postprocessing techniques that enable QIM to fully achieve capacity, not only against Gaussian attacks but also against other types of attacks as well. One practical postprocessing technique we develop we refer to as distortion compensation. Distortion compensation has the property that when suitably optimized it is sufficient for use in conjunction with QIM to achieve capacity against Gaussian attacks and against square-error distortion-constrained attacks. More generally, we present the results of a comparative information theoretic analysis of the fundamental performance limits of QIM, distortion-compensated QIM, and other watermarking methods and demonstrate practically achievable gains with experimental results.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
S cycling: Characterization of natural communities of sulfate-reducing bacteria by 165 rRNA sequence comparisons

Past studies of microbial communities responsible for geochemical transformations have been limited by an inability to representatively cultivate, and then identify, the constituent members. Ribosomal RNA sequences, particularly 16S-like rRNAs, provide a measure of phylogenetic relationship that can now be used to examine the structure and diversity of microbial communities. Sulfate-reducing bacteria (SRB) play an important role in the sulfur cycle and the terminal mineralization of organic matter in estuarine and marine environments. Because the Gram-negative mesophilic SRB comprise a phylogenetically coherent assemblage, their communities are well suited to explorations through rRNA sequence-based methodologies. In this study we related molecular biological methods using rRNA probes to geochemical measurements at two different sites. At an unvegetated site in northwest Florida, rates of sulfate reduction were low and SRB rRNA comprised about 5% of the total rRNA extracted from the sediment. The other site, a salt marsh in New Hampshire, had higher rates of sulfate-reduction with SRB rRNA accounting for up to 30% of the total rRNA extracted from the sediment. SRB community structure differed dramatically between the two sites with Desulfobulbus rRNA much less abundant in the unvegetated site than in the salt marsh. The differences in these SRB communities reflect differences in the ecology of their habitats.
Nonclassical eigenvalue asymptotics

Abstract The leading asymptotics for the growth of the number of eigenvalues of the two-dimensional Dirichlet Laplacian in the regions { (x,y)∥x¦ μ ¦y¦⩽ 1 } and for −Δ + ¦x¦ α ¦ y¦ β all of which are non-Weyl because of infinite phase space volumes are computed. Along the way, a general inequality on quantum partition functions computed in a kind of Born-Oppenheimer approximation is proved.
Scaffold-associated regions in the human type I interferon gene cluster on the short arm of chromosome 9.

Abstract Scaffold-associated regions (SARs) function at the level of modeling or shaping the chromatin of DNA into loop domains. We have mapped 36 SARs in the human type I interferon ( IFN ) gene complex on chromosome 9, band p21-22, to examine the overall structure of this gene complex. A total of 29 strong SARs and 7 weak SARs were mapped to the flanking regions of the different interferon genes. Twenty-two strong SARs mapped to the flanking regions of 13 interferon ( IFNA ) α genes; 2 strong SARs mapped to one interferon ω ( IFNW ) gene; 2 strong SARs mapped to one interferon α pseudogene ( IFNAP ); and 3 strong SARs mapped to two interferon ω pseudogenes ( IFNWP ). One weak SAR mapped to the flanking region of one IFNA gene, whereas 6 weak SARs flanked four IFN pseudogenes ( P11, P12 P20, P23 ). The IFN SAR structure was comparable between the BV173 leukemia cell line and the U373 glioma cell line. Analysis of two glioma deletion breakpoint junctions, where breaks occur within and outside the IFN gene cluster, revealed an association with SARs. IFN SARs showed evidence for cooperativity among the SARs, while DNA sequence analysis revealed a series of clustered A-tracts within strong SARs. These data suggest that the IFN genes may be organized into a series of small (2–10 kb) DNA loop domains, with each loop containing a coding region flanked by SARs. In our model, the SAR enrichment and the clustering of A-tracts observed at the SARs within the IFN gene complex represent a higher level of chromatin organization, which may predispose this region to breakage.
Ontogeny of mammalian cardiac α1-adrenergic receptors

We find similar number of α1-adrenergic receptors in fetal mouse hearts of 15–20 day gestational age as compared to adult mouse hearts, and a significantly greater number of α1-adrenoceptors in the early neonate (7–21 days) hearts. Cardiac norepinephrine (NE) concentrations were extremely low inthe fetus and increased continuously after birth to reach adult levels at about 21 days of age. Te cardiac α1-adrenergic receptors prior to the development of a presynaptic component (NE) and show a dramatic increase in density without a change in affinity in the early neonate which then decrease with innervation.
THE EFFECTS OF EDTA (ETHYLENEDINITROTETRAACETIC ACID) ON THE SURVIVAL AND DEVELOPMENT OF SHRIMP NAUPLII (Penaeus stylirostris STIMPSON) AND THE INTERACTIONS OF EDTA WITH THE TOXICITIES OF CADMIUM, CALCIUM, AND PHENOL

To examine the hypothesis that EDTA increases hatching rates and survival of penaeid shrimp larvae by decreasing the toxicities of heavy metals through chelation, the toxicity of cadmium, a highly toxic metal, was compared to the toxicities of calcium and phenol in both the presence and absence of EDTA. In addition, the toxicity of EDTA at higher concentrations was examined. The toxicities of EDTA, cadmium, calcium, and phenol were evaluated in terms of the percentage of nauplii surviving after 24 hours of exposure and the percentage of nauplii which metamorphosed to protozoea. The toxicities of cadmium, calcium, and phenol were also determined in the presence of EDTA. EDTA concentrations of 1.34 mM were lethal to nauplii. At 0.67 mM, EDTA reduced the percentage of nauplii which metamorphosed to protozoea but below 0.3 mM neither survival nor metamorphosis were affected. Cadmium, phenol, and calcium were lethal to nauplii at concentrations of 20 μM, 7 mM, and 400 mM, respectively. Metamorphosis was blocked by concentrations of 1 μM, 0.9 mM, and 200 mM, respectively. However, in the presence of 0.3 mM EDTA, the toxicities of cadmium and calcium were reduced. Cadmium concentrations of 20 μM did not affect either survival or metamorphosis in the presence of EDTA. In calcium concentrations of 50 and 100 mM, the percentage of nauplii that metamorphosed to protozoea was increased by the addition of EDTA. The interaction of EDTA and phenol toxicity was not significant.
trans-Free Margarines Prepared with Canola Oil/Palm Stearin/Palm Kernel Oil-Based Structured Lipids

Structured lipids (SLs) for formulating trans-free margarines were synthesized by lipase-catalyzed interesterification of the blends of canola oil (CO), palm stearin (PS), and palm kernel oil (PKO) in weight ratios (CO/PS/PKO) of 40:60:0, 40:50:10, 40:40:20, 40:30:30, 50:30:20, and 60:25:15. The atherogenicity was determined using fatty acid profiles. We also determined the physical properties (melting/crystallization profiles, solid fat content, polymorphism, and microstructure) of SLs and the textural properties of margarines made with the SLs. The SLs from the 50:30:20 and 60:25:15 blends had atherogenic indices similar to or lower than those of the commercial trans (CTMF) and similar to the trans-free margarine fats (CTFMF). SLs from the blends with PKO contained a wide range of fatty acids (C6−C20) and had more β′ than β polymorphs. Margarines made with SLs from 50:30:20 and 60:25:15 blends possessed similar hardness, adhesiveness, or cohesiveness to margarines made with CTMF and CTFMF, respectively....
Attosecond time-scale feedback control of coherent X-ray generation

Abstract High-harmonic generation is an extreme, high-order, nonlinear process that converts intense, ultrafast, visible and infrared laser light pulses coherently into the soft X-ray region of the spectrum. We demonstrate that by optimizing the shape of an ultrafast laser pulse, we can selectively enhance this process by promoting strong constructive interference between X-ray bursts emitted from adjacent optical cycles. This work demonstrates that coherent control of highly nonlinear processes in the strong-field regime is possible by adjusting the relative timing of the crests of an electromagnetic wave on a sub-optical cycle, attosecond time scale.
Clinical and design update on the development and testing of a one-piece, bifurcated, polytetra-fluoroethylene endovascular graft for abdominal aortic aneurysm exclusion: the Endologix device.

Continued success and expanding use of endovascular prostheses to manage aortic aneurysms has encouraged development of novel prototypes that offer advantages for low-profile delivery of durable devices. The Endologix device, currently being acquired by CR Bard, Incorporated, is a new, one-piece self-expanding polytetrafluoroethylene prosthesis that offers an alternative to current modular and fabric devices. Although only preliminary U.S. and expanding European experiences are available, the unique features of this prosthesis appear to offer an appealing alternative.
Introducing traditional students to individualized assessment: The biocontextualist rorschach with lessons from dream work

Abstract Even in clinical programs that are largely unreceptive to individualized assessment, students can develop a modest version of collaborative testing during their practicum experiences. The major steps in such a brief exposure are described, with particular attention to the Rorschach. The model includes evaluating lapses in form level from an interactionist perspective, taking account of subjective interpretations of test instructions, and applying techniques of Bossian dream exploration to the analysis of idiographic projections.
Bending the parallels of the Poggendorff figure

The two angles formed by the intersection of the transversal segment and parallel line of the Poggendorff figure were independently varied in size by bending the parallel at the intersection. The standard illusion could be enhanced or reversed by manipulating the size of the obtuse (β) angle. Regardless of acute (α) angle size, a maximal illusion obtained for α = 120 deg, and the illusion was reversed for figures in which β< α.
Immunocytochemical localization of CD44 in the mouse retina.

The transmembrane glycoprotein CD44 is a cell adhesion molecule which has recently been localized in a variety of cell types. It mediates cell attachment to extracellular matrix components and also binds to the actin cytoskeleton within the cell. In this study, the presence and distribution of CD44 in the mouse retina was investigated in order to determine whether this molecule might be important for retinal cell adhesion. With immunoperoxidase techniques, positive labeling for CD44 was found at the level of the outer limiting membrane and in the region just sclerad to it. However, from these light microscope results it was not clear if the label was in the photoreceptor inner segments, the Muller cell apical microvilli, or both. In order to answer this question, cryoultramicrotomy and immunogold labeling were used to demonstrate that CD44 is specifically localized to the Muller cell microvilli which appose the interphotoreceptor matrix. Western blotting of a retina homogenate showed that the anti-CD44 antibody is specific for a protein of approximately 90 kDa which is the correct molecular weight for the most abundant form of CD44. These results, along with the known binding characteristics of CD44 for the extracellular matrix, suggest that CD44 could play a role in mediating the attachment of the neural retina to components of the interphotoreceptor matrix.
Hopping transport on a randomly substituted lattice in the presence of dilute deep traps

Our recent theory of hopping transport of excitations or charge carriers among particles randomly distributed on the sites of a lattice is extended here to include the presence of a low concentration trap species. We present an exact diagrammatic analysis of the configuration-averaged Green function of the pauli master equation for this problem. We obtain a non-perturbative approximation to the Green function that is expected to be accurate at both high and low donor concentration for low trap concentration. The approximation can be carried out for any lattice type in which any two sites can be transformed into one another by a symmetry operation, and a transfer rate of any distance dependence. We present calculations of the observable in a steady-state excitation transfer and trapping experiment that illustrate the effect of dimensionality and of the distance dependence of the transfer rate on this observable.
Periodic points and rotation numbers for area preserving diffeomorphisms of the plane

Letf be an orientation preserving diffeomorphism ofR2 which preserves area. We prove the existence of infinitely many periodic points with distinct rotation numbers around a fixed point off, provided only thatf has two fixed points whose infinitesimal rotation numbers are not both 0.
Insights from Xanthine and Uracil DNA Glycosylase Activities of Bacterial and Human SMUG1: Switching SMUG1 to UDG

Single-strand-selective monofunctional uracil DNA glycosylase (SMUG1) belongs to Family 3 of the uracil DNA glycosylase (UDG) superfamily. Here, we report that a bacterial SMUG1 ortholog in Geobacter metallireducens (Gme) and the human SMUG1 enzyme are not only UDGs but also xanthine DNA glycosylases (XDGs). In addition, mutational analysis and molecular dynamics (MD) simulations of Gme SMUG1 identify important structural determinants in conserved motifs 1 and 2 for XDG and UDG activities. Mutations at M57 (M57L) and H210 (H210G, H210M, and H210N), both of which are involved in interactions with the C2 carbonyl oxygen in uracil or xanthine, cause substantial reductions in XDG and UDG activities. Increased selectivity is achieved in the A214R mutant of Gme SMUG1, which corresponds to a position involved in base flipping. This mutation results in an activity profile resembling a human SMUG1-like enzyme as exemplified by the retention of UDG activity on mismatched base pairs and weak XDG activity. MD simulations indicate that M57L increases the flexibility of the motif 2 loop region and specifically A214, which may account for the reduced catalytic activity. G60Y completely abolishes XDG and UDG activity, which is consistent with a modeled structure in which G60Y blocks the entry of either xanthine or uracil to the base binding pocket. Most interestingly, a proline substitution at the G63 position switches the Gme SMUG1 enzyme to an exclusive UDG as demonstrated by the uniform excision of uracil in both double-stranded and single-stranded DNA and the complete loss of XDG activity. MD simulations indicate that a combination of a reduced free volume and altered flexibility in the active-site loops may underlie the dramatic effects of the G63P mutation on the activity profile of SMUG1. This study offers insights on the important role that modulation of conformational flexibility may play in defining specificity and catalytic efficiency.
Developing a playground injury prevention plan

Playgrounds are a major source of unintentional injuries in the school environment. In fact, 80% of all injuries on public playground equipment happen at school. Thus, the need for developing a playground injury prevention plan is critical to provide safe educational outdoor environments for children. The S.A.F.E.trade mark framework for injury prevention is the first step in preventing playground injuries. This article highlights suggestions that school nurses can implement in creating an effective playground injury prevention program at their schools.
Subcellular localization of α-2A-adrenergic receptors in the rat medial nucleus tractus solitarius: Regional targeting and relationship with catecholamine neurons

α-2A-adrenergic receptor (α2A-AR) agonists modulate diverse autonomic functions. These actions are believed to involve functionally specialized, second-order neurons in catecholamine-containing portions of the medial nucleus tractus solitarius (mNTS) at both intermediate (NTSi) and caudal (NTSc) levels. However, the cellular mechanisms subserving α2A-AR-mediated actions within the mNTS have yet to be established. Immunocytochemistry was employed to examine the subcellular distribution of α2A-AR in both the intermediate and caudal mNTS and its association with cells containing the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH). Quantitative regional comparison using immunogold showed that this receptor was distributed differentially to dendrites (NTSi, 46%; NTSc, 31%) and glia (NTSi, 29%; NTSc, 48%) at different levels of the NTS. Somata, axons, and terminals less frequently contained α2A-AR. The subcellular distribution of α2A-AR relative to catecholaminergic neurons also was similar within both subregions. Approximately 50% of α2A-AR-labeled somata also contained TH. In somatic profiles, α2A-AR labeling was often found in the cytosol and in association with endoplasmic reticulum and Golgi complexes, sites of receptor synthesis and trafficking. Approximately 20% of α2A-AR-immunoreactive dendrites also contained TH, where the receptor was often found on extrasynaptic portions of the plasma membrane near unlabeled terminals, some of which made symmetric contacts. However, TH-labeled terminals and dendrites usually were detected in the neuropil at a short distance (<10 μm) from α2A-AR-labeled neurons. α2A-AR-labeled glia frequently apposed unlabeled dendrites and terminals and were often located near TH-immunoreactive dendrites. These results indicate that, within the mNTS, α2A-AR is involved in a variety of autonomic processes, including postsynaptic modulation of mostly noncatecholaminergic dendrites, as well as influencing glia functions. J. Comp. Neurol. 433:193–207, 2001. © 2001 Wiley-Liss, Inc.