cssi/SciSciGPT-SciSciNet huggingface dataset:
Liver cancers and other hepatic disease from the Adult/Adolescent Spectrum of HIV-related Diseases (ASD) Project

Materials and methods The multisite ASD Project followed 29,491 HIV-infected individuals receiving medical care in 11 U.S. metropolitan areas for an average of 2.4 years and a total of 69,487 person-years. ASD collected data on the presentation, treatment, and outcomes related to HIV infection, including viral hepatitis screening and liver-specific complications including hepatic neoplasms. Data were restricted to the HAART era, 1998-2004.
Chapter 8 Spectral imaging and its use in the measurement of Förster resonance energy transfer in living cells

Publisher Summary This chapter focuses on the theory of linear unmixing of spectral images, and describes how it can be used to acquire accurate Forster resonance energy transfer (FRET) measurements. Many of the technical problems encountered when acquiring FRET images can be eliminated by analyzing the data encoded in spectral images with an image analysis algorithm called linear unmixing. The chapter describes how spectral imaging can be used to detect and measure FRET and to convey the strengths and weaknesses of the approach. Spectral imaging microscopy is a relatively new form of multidimensional fluorescence microscopy that can potentially eliminate several of the obstacles one encounters in FRET imaging. FRET is not a rare event in biology as it is fundamental to the process of photosynthesis. FRET can also occur, often unintentionally, on the introduction of fluorophores in a biological milieu, particularly in crowded environments such as in membranes. The chapter demonstrates the fundamental problem in quantitative fluorescence microscopy, and outlines how spectral imaging can be used to measure the true abundance of fluorophores, even when FRET is occurring.
Granulometric Size Density for Segmented Random-Disk Models

This design of optimal filters depends upon the random processes under consideration and the operator class from which a filter is to be chosen. Analytic derivation of an optimal filter is facilitated by finding partial descriptors of the random processes that facilitate analytic derivation of an optimal filter from the descriptors—for linear filtering, derivation of the optimal filter is via the covariance function. For nonlinear filtering of random sets (binary images), an analogous approach applies to the derivation of an optimal granulometric bandpass filter (GBF) by means of the granulometric size densities (GSDs) of the signal and noise. A GBF operates by passing or not passing components of a random set. For simply shaped grains having convenient analytic description, finding the GSD is not too difficults however, when the disjoint union results from the segmentation of a non-disjoint union, the resulting process, and its GSD, can become very complex. This paper postulates a constrained overlap random-set model, and then finds the GSD for the segmented random set. The primary grain of the random model is a disk of random radius and segmentation is via the watershed transformation. Even for a union of disks, modest intersection greatly enhances the difficulty of finding the GSD, and therefore of designing optimal bandpass filters. Although application to disks is specialized, it gives quantitative insight into the effects of grain overlapping and segmentation. Such restriction to a tractable model is not uncommon in the literature of random sets when quantitative estimation results are desired.
Identification of a TPA-responsive element mediating preferential transactivation of the galanin gene promoter in chromaffin cells.

Abstract The gene encoding the neuropeptide galanin is upregulated by second messenger signal transduction pathways in bovine chromaffin cells. To identify its transcriptional regulatory elements, 5'-flanking sequences of the galanin gene were transiently transfected into primary cultures of bovine chromaffin cells within reporter gene constructs. Multiple regions of the galanin 5' flank seem to be necessary for basal activity. The most promoter-proximal of these regions contains a sequence (TGACG) -66 to -62 nucleotides upstream from the transcriptional start site which mediates stimulation by 12-O-tetradecanoylphorbol-13-acetate (TPA), as demonstrated by site-directed mutagenesis and cis-activation experiments. This cis-regulatory element mediates preferential TPA stimulation of transcription from the galanin promoter in chromaffin cells compared with bovine endothelial or HeLa cells. DNA-protein binding assays indicate that an oligonucleotide that includes the galanin TPA-responsive element (GTRE) binds specifically to proteins from nuclear extracts of chromaffin cells. TPA treatment persistently increases this binding activity in chromaffin but not in endothelial cells. Mutation of the galanin promoter within the -66 to -62 region renders it unresponsive to transcriptional stimulation by TPA, and a correspondingly mutated oligonucleotide fails to bind chromaffin cell nuclear proteins in a gel-shift assay. Chromaffin cell nuclear extracts also contain proteins that bind consensus TPA-responsive (TRE) and cyclic AMP-responsive (CRE) elements. GTRE, TRE, and CRE oligonucleotides all compete more efficiently for protein binding to their labeled congeners than for protein binding to either of the other labeled oligonucleotides, suggesting that the GTRE, TRE, and CRE oligonucleotides, suggesting that the GTRE, TRE, and CRE oligonucleotides each bind unique as well as common proteins, likely to be members of the Jun/Fos and cAMP-responsive element-binding protein/activating transcription factors (CREB/ATF) families of transcription factors, in chromaffin cells.
Use of Erythropoietin Following Emergent Surgery in a Jehovah'S Witness

We report a case of a 25-year-old, female Jehovah'S Witness (JW) with severe anemia secondary to emergent salpingectomy who was treated with high dose human recombinant erythropoietin (rHu-EPO). Po...
The Effect of the Top Two Primary on the Number of Primary Candidates

Objectives Washington State held its first “top two primary” in 2008. Under this system, the two candidates receiving the most votes move on to the general election, regardless of party affiliation. This study empirically examines the potential incentive under this top two primary system for each political party to discourage “excess” party candidates from entering primary contests. Methods We examine this possibility by looking at the Washington State Legislative Primaries in 2004, 2006, 2008, and 2010. With these data, we estimate the factors impacting the number of primary candidates in a race for each political party, including the change in the primary format in 2008. Results Our results indicate that the switch to the top two primary reduced the likelihood of having multiple Democratic candidates in a race, reduced the number of “excess” Democratic candidates, but did not have a significant impact on Republican candidates. Conclusion With many states revising their primary systems, an understanding of the incentives present under alternative systems is critical. As such, the results presented in this study provide evidence that the top two primary gives the political parties an incentive to discourage excess primary candidates.
The Adoption of Japanese Manufacturing Management Techniques in Korean Manufacturing Industry

After four consecutive years′ trade surplus, Korea′s climbing foreign trade deficit in 1990 is a clear signal that the nation should attempt to improve the performance of its manufacturing industry. However, there has not been much study on how manufacturing management is conducted in Korea and how it might be improved. Too much emphasis has been placed on macro policy variables such as tax, exchange rates and interest rates, which have only short‐term effects on competitiveness. The task for Korean manufacturing industry is to meet the challenges before it and be in a position to compete with other countries by providing high‐quality products at the right price. The most affordable and practical alternative is to make innovations in the current manufacturing process in order to enhance productivity and competitiveness. Studies the adoption and application of Japanese manufacturing management techniques under Korean conditions. Also provides a number of cases of their implementation in Korea and outlines ...
Condensation of R134a flowing inside helicoidal pipe

Condensing heat transfer and pressure drop characteristics of an ozone-friendly refrigerant HFC-134a (hydrofluorocarbon 134a) flowing inside a 12.7 mm helicoidal tube were investigated experimentally to obtain heat transfer data and correlations. For long helicoidal pipe, heat transfer measurements were performed for the refrigerant flow mass fluxes from 100 to 400 kg/m 2 /s, in the cooling water flow Reynolds number range of 1500< Rew < 9000 at fixed system temperature (338C) and cooling tube wall temperature (128C and 228C). With the increase of mass flux, the overall condensing heat transfer coeAcients of R134a increased, and slowly the pressure drops also increased. However, with the increase of mass flux (or the cooling water flow Reynolds number), the refrigerant side heat transfer coeAcients decreased. The eAects of cooling wall temperature on heat transfer coeAcients and system pressure drops were considered. Predictive correlations valid over the above water flow Reynolds number ranges and refrigerant flow mass flux were proposed. Helicoidal pipe heat transfer characteristics were compared with data for horizontal straight pipe from literature reports. 7 2000 Elsevier Science Ltd. All rights reserved.
MPEG Video Encryption Algorithms

Multimedia data security is important for multimedia commerce. Previous cryptography studies have focused on text data. The encryption algorithms developed to secure text data may not be suitable to multimedia applications because of the large data size and real time constraint. For multimedia applications, light weight encryption algorithms are attractive. We present four fast MPEG video encryption algorithms. These algorithms use a secret key to randomly change the sign bits of Discrete Cosine Transform (DCT) coefficients and/or the sign bits of motion vectors. The encryption is accomplished by the inverse DCT (IDCT) during the MPEG video decompression processing. These algorithms add a small overhead to MPEG codec. Software implementations are fast enough to meet the real time requirement of MPEG video applications. The experimental results show that these algorithms achieve satisfactory results. They can be used to secure video-on-demand, video conferencing, and video email applications.
Serial cardiac catheterizations in infundibular and pulmonic stenosis.

A 43-year-old man with infundibular and pulmonic stenosis underwent two cardiac catheterizations over a seven-year period. With passage of time a decrease in cardiac index and severity of the infundibular stenosis was observed. Little change was observed in the valvular stenosis gradient Reduction in obstruction at the infundibular level can probably be ascribed to an increase in the right ventricular volume.
Substrate and phospholipid specificity of the purified mannitol permease of Escherichia coli

D-Mannitol is transported and phosphorylated by a specific enzyme II of the phosphotransferase system of Escherichia coli. This protein was purified previously in detergent solution and has been partially characterized. As one approach in understanding the structure and mechanism of this enzyme/pcrmease, we have tested a number of sugar alcohols and their derivatives as substrates and/or inhibitors of this protein. Our results show that the mannitol permease is highly, but not absolutely, specific for D-mannitol. Compounds accepted by the enzyme include those with substitutions in the C-2 (= C-5) position of the carbon backbone of the natural substrate as well as D-mannonic acid, one heptilol and one pentitol. All of these compounds were both inhibitors and substrates for the mannitol permease except for D-mannoheptilol, which was an inhibitor but was not phosphorylated by the enzyme. No compound examined, however, exhibited an affinity for the enzyme as high as that for its natural substrate. We have also investigated the phospholipid requirements of the mannitol permease using phosphotipids purified from E coli. The purified protein was significantly activated by phosphatidylethanolamine, but little activation was observed with phosphatidylglycerol or cardioli-pin. These observations partially delineate requirements for interaction of sugar alcohols and phospholipids with the mannitol permease. They suggest approaches for the design of specific active site probes for the protein, and strategies for stabilizing the enzyme's activity in vitro.
The stable isotopic composition of bluefin tuna (Thunnus thynnus) otoliths: Evidence for physiological regulation

Abstract 1. 1. The stable isotopic composition of giant (>350kg) bluefin tuna ( Thunnus thynnus ) was determined for fish held under known environmental conditions where gut temperatures were monitored. 2. 2. It was discovered that otolith stable isotopes were not deposited in equilibium with hydrographic conditions. 3. 3. The oxygen isotopic composition appeared to be a function of body and brain temperature, which was regulated through a thermoregulatory mechanism. 4. 4. The depletion of 13 C in the otoliths established that the carbon isotopic composition of the otolith aragonite was fractionated by metabolic processes. 5. 5. These findings suggest that it is possible to study the physiological history of bluefin tuna and maybe other fish species through the use of the stable isotopic composition of otoliths.
Air Drying Bacon Slices to Reduce aw: An Anti‐Clostridial Alternative to Sodium Nitrite

Low temperature air drying studies were conducted on bacon slices to determine the practicality and effectiveness of this method for reducing water activity (aw) as an anti-clostridial alternative to sodium nitrite. Isotherms were developed to determine the extent of moisture removal required to achieve aw = 0.92 or lower; these levels have been found to inhibit C. botulinum. Drying to these levels have been found to inhibit C. botulinum. Drying to these levels of inhibition can be accomplished in approximately 1.75 hr. Drying rates are significantly affected by air temperature, air flow rate, and slice overlap. Experimental data indicate drying can be accomplished with no substantial change in product quality.
From Mee-gook to Gook: The Cold War and Racialized Undocumented Capital in Chang-rae Lee's Native Speaker

In his 1995 novel Native Speaker, Chang-rae Lee inserts an account of the pedagogical moment in which his Korean American narrator experi ences the lesson of what it means to be a "good" or "bad" Korean. This moment literally takes place in the classroom. Henry Park recalls, "I read my junior encyclopedia.... The entry didn't mention any Koreans except for Syngman Rhee and Kim Il Sung, the Communist leader. Kim was a bad Korean. In the volume there was a picture of him wearing a Chinese jacket. He was fat-faced and maniacal. Bayonets were in the frame behind him. He looked like an evil robot." Pressed to present an oral report to his class that would be received favorably, Henry decides to be a "good
Acute coronary hemodynamic response to cigarette smoking in patients with coronary artery disease.

The acute changes in coronary blood flow and coronary resistance that occur in response to cigarette smoking have not been accurately determined. To define the factors that affect this response, coronary sinus blood flow was measured in 16 patients (group 1) with coronary artery disease and in 6 patients (group II) without angiographically detectable coronary disease. Seven patients (group IA) had severe (≥75%) proximal left coronary lesions and nine patients (group IB) had significant distal lesions with 50% or less proximal stenoses. Group I had a smaller overall increase ( ↑ 1.6 ± 5.3%) in coronary sinus blood flow than did group II ( ↑ 7.7 ± 6.1 %) (p It is concluded that smoking increases coronary resistance in patients with coronary artery disease. A greater impact is observed in patients with a severe proximal stenosis than in those with a distal stenosis. It is proposed that smoking increases coronary artery tone at the site of the stenosis, limiting the coronary flow response proportionally to the size of the affected vascular bed.
Dealing with under- and over-dispersed count data in life history, spatial, and community ecology

Count data arise frequently in ecological analyses, but regularly violate the equi-dispersion constraint imposed by the most popular distribution for analyzing these data, the Poisson distribution. Several approaches for addressing over-dispersion have been developed (e.g., negative binomial distribution), but methods for including both under-dispersion and over-dispersion have been largely overlooked. We provide three specific examples drawn from life-history theory, spatial ecology, and community ecology, and illustrate the use of the Conway-Maxwell-Poisson (CMP) distribution as compared to other common models for count data. We find that where equi-dispersion is violated, the CMP distribution performs significantly better than the Poisson distribution, as assessed by information criteria that account for the CMP's additional distribution parameter. The Conway-Maxwell-Poisson distribution has seen rapid development in other fields such as risk analysis and linguistics, but is relatively unknown in the e...
A variational formulation for convection-diffusion problems

A variational principle is proposed that under certain restrictions is shown to be equivalent to the advection-diffusion boundary value problem. Based on this variational principle, an upwind finite element method is derived that precludes spurious oscillations while possessing optimal convergence properties even in the multidimensional case. The formulation also points to a canonical choice of weighting functions for the Petrov-Galerkin method proposed by the Dundee and Swansea groups.
Bronchogenic carcinoma metastatic to the lip and the mandible

Two cases of metastatic bronchogenic carcinoma are reported. Possible pathways of dissemination are discussed, along with the symptoms, diagnosis, and management of these lesions.
Chamber and Vessel Quantification in Pediatric Echocardiography: What Do the Guidelines Teach Us?

The American Society of Echocardiography has recently published guidelines for chamber and vessel quantification during a pediatric echocardiogram. Because the sizes of cardiovascular structures increase with somatic growth, pediatric quantification requires the adjustment of measurements for the effects of body size in order to determine when a measurement is outside the normal range. A universal pediatric normative database of measurements from a normal population encompassing the full range of body sizes encountered in pediatrics would provide clinicians and researchers a powerful tool to distinguish normal from abnormal values and aid in the management of children with heart disease. However, there are still challenges in the complete acceptance of the recommended pediatric protocols for each cardiac segment, mostly because of historical standard practices, differences with the quantification guidelines for adults, and varying methodologies utilized in currently available pediatric normative databases.
MESOSCALE AND SYNOPTIC SCALE TRANSPORT OF AEROSOLS

An overview is presented of mesoscale and synoptic-scale (macroscale) aerosol transport as observed in recent air pollution field studies. Examples of mesoscale transport systems are discussed, including urban plumes, sea breezes, the mountain-valley wind cycle, and the urban-heat-island circulation. The synoptic-scale systems considered are migrating high- and low-pressure systems. Documented cases are reviewed of aerosol transport in the various mesoscale systems, aerosol accumulation and transport in high-pressure systems, and acid precipitation in low-pressure systems. The characteristics of the transported aerosols are identified, along with the chemical species that occur primarily in aerosols in the accumulation mode (particle diameters of 0.1-3 microns). It is shown that aerosol particles in the accumulation mode are the most important in terms of synoptic-scale and mesoscale transport and that such particles are primarily responsible for visible haze.
Computer simulations of cardiac defibrillation: a look inside the heart

This paper presents for the first time computer simulations of electrical defibrillation in the heart in a realistic model of cardiac structure and membrane ionic processes. The content of the paper focuses primarily on model development. Two models of defibrillation are presented here: a three-dimensional slice of the canine heart that encompasses both ventricular cavities, and a full rabbit heart model. The two sets of simulations employing the described models demonstrate transmural electrical activity in the heart during and after the shock that has not yet been observed experimentally due to present limitations in recording procedures. The models developed here are intended for exploration of the mechanisms for defibrillation as well as to address issues pertinent to the clinical procedure of defibrillation such as electrode location and shock waveform.
Spacecraft charging at synchronous orbit.

Observation that ATS 5 can charge to potentials as high as 10,000 volts during eclipse, and as high as 200 volts in sunlight. This charging has been used to infer the presence of the plasmasphere at synchronous altitude in the midnight region, and its prompt disappearance when hot plasma is injected in association with substorms. Although injected plasma has a density of 1.0 per cu cm the remaining cold plasma (less than 50 eV) has a density of 0.01 per cu cm. A mathematical model of ATS 5 has been constructed that can be used to predict spacecraft potentials. In addition, parts of ATS 5 can charge to several hundred volts without affecting the overall spacecraft potential appreciably.
Performance of Fourth-Grade Students with Learning Disabilities on Multiplication Facts Comparing Teacher-Mediated and Technology-Mediated Interventions: A Preliminary Investigation

Instructional applications (apps) are educational software programs that can be accessed via mobile technologies (e.g., iPad, smartphone) and used to help students acquire various academic skills, including mathematics. Although research suggests that app-based instruction (AI) can be effective, there is a paucity of research comparing AI, to teacher-directed instruction (TDI) or to a combination of instructional approaches (CI) involving both AI and TDI in tandem. In an alternating treatments design, we compared AI, TDI, and CI conditions during instruction targeting multiplication facts with six students with learning disabilities. Results were inconsistent across students, and no condition emerged as consistently better than the others. Students completed social validity rating scales, and all approaches were favored by at least one student. Our results support findings from previous research involving similar comparisons between these instructional formats in which no (or minimal) differences across conditions were detected. We conclude that there may not be a meaningful difference between the outcomes achieved using AI, TDI, or CI for many students. Results are discussed in terms of directions for the future research.
Infection of human astrocytoma cells with simian-human immunodeficiency virus results in up-regulation of gene expression and altered growth properties.

Recent reports of human immunodeficiency virus-1 (HIV-1) infection of astrocytes suggest a role for astrocytes in HIV encephalitis. In this study, we infected a human astrocytoma cell line with a pathogenic simian HIV (SHIV50OLNV) and examined growth patterns and immunomodulatory genes. Approximately 1% of uninfected cells in culture expressed glial fibrillary acid protein (GFAP) whereas 40% of the cells expressed GFAP at 7 days post-inoculation along altered growth patterns. Using targeted cytokine cDNA arrays, we found that SHIV50OLNV infection resulted in the up-regulation of several genes including metalloproteinase bone morphogenic protein 1 and chemokines monocyte chemoattractant protein 1 and stromal cell derived factor 1α. These data suggest that astrocytic activation, altered morphology and up-regulation of immunomodulatory genes in response to SHIV infection may participate in initiation of inflammation and trafficking of infected monocytes/macrophages into the central nervous system, potentiating the development of HIV encephalitis.
Neuroethics and Neuroimaging: Moving Toward Transparency

Without exaggeration, it could be said that we are entering a golden age of neuroscience. Informed by recent developments in neuroimaging that allow us to peer into the working brain at both a structural and functional level, neuroscientists are beginning to untangle mechanisms of recovery after brain injury and grapple with age-old questions about brain and mind and their correlates neural mechanisms and consciousness. Neuroimaging, coupled with new diagnostic categories and assessment scales are helping us develop a new diagnostic nosology about disorders of consciousness which will likely improve prognostication and suggest therapeutic advances. Historically such diagnostic refinement has yield therapeutic advances in medicine and there is no reason to doubt that this will be the case for disorders of consciousness, perhaps bringing relief to a marginalized population now on the periphery of the therapeutic agenda. In spite of this promise, the translation of research findings into the clinical context will be difficult. As we move from descriptive categories about disorders of consciousness, like the vegetative or minimally conscious states, to ones further specified by integrating behavioral and neuroimaging findings, humility not hubris should be the virtue that guides the ethical conduct of research and practice.
Simulation based study of on-chip antennas for a reconfigurable hybrid 3D wireless NoC

The feasibility of using on-chip antennas for a reconfigurable 3D wireless network-on-chip (3D-WiNoC) on a 3D integrated circuit (IC) is shown. The reconfigurable 3D-WiNoC is designed with on-chip antennas which are proposed to be used in conjunction with the metal interconnects making it a hybrid design. The feasibility of the on-chip antennas is shown by performing a 3-D finite element method (FEM) based full wave electro-magnetic analysis on a 3D IC model. The 3D IC is modeled according to a complimentary metal oxide semiconductor (CMOS) silicon on insulator (SoI) Benzocyclobutene (BCB) polymer adhesive bonding 3-D circuit integration technology. It is shown that it is possible to have two different frequency domains for the signal sources and the dynamic switching of the signal sinks between the two frequency domains, with minimal design and area overhead. When implemented, the proposed hybrid network architecture with two frequency channels can reduce the latency and increase the network throughput.
Get research-ready.

Nursing research promotes quality patient care and cost reduction. Learn what barriers exist to nurses conducting research and implementing findings, and how one hospital overcame them.
Highly deacetylated chitosan and its properties

A preparative method has been established for obtaining chitosan products which have a desired degree of deacetylation of up to virtually 100%. Effective deacetylation was attained by intermitently washing the intermediate product in water two or more times during the alkali treatment. The weight average molecular weight (Mw) of the product, which was measured by gel permeation liquid chromatography, was about 5 × 105 at the highest deacetylation of nearly 100%, and the degradation of the molecular chain was not so significant. Tensile strength of the wet film increased markedly with increasing degree of deacetylation, while the dry film did not show a corresponding significant increase of the tensile strength. In the infrared spectra of chitosan film new sharp bands appeared especially at the high degree of deacetylation. This was attributed to increased “crystallization” brought about by high deacetylation.
Pathogenesis and outcome of Paecilomyces keratitis.

Purpose To examine the clinical pathology and management of Paecilomyces lilacinus keratitis. Design Observational case series, literature review, and laboratory study. Methods Characteristics and outcome of 17 patients with laboratory-confirmed Paecilomyces keratitis treated at 2 referral centers were combined with 25 previously reported cases. Experimental models were developed by topically inoculating a human corneal isolate of P. lilacinus onto murine eyes and onto human donor corneas. Results Of 42 reported eyes with Paecilomyces keratitis, 13 (31%) were associated with chronic keratopathy or previous ocular surgery, 11 (26%) followed corneal trauma, and 10 (24%) occurred in soft contact lens wearers. Medical cure occurred in 13 (31%), including 9 of 31 eyes (29%) treated with natamycin or amphotericin B. Penetrating keratoplasty or other surgery was performed in 29 (69%). In vitro testing of P. lilacinus indicated resistance to natamycin and amphotericin B but susceptibility to ketoconazole and voriconazole. Experimental inoculation after superficial scarification established moderately severe corneal paecilomycosis by hyphae and conidia in immunosuppressed mice and in explanted donor corneas. Conclusions P. lilacinus is an emerging fungal pathogen that infects corneal tissue by filamentous invasion with occasional intrastromal sporulation. P. lilacinus keratitis does not reliably respond to natamycin or amphotericin B and has often required therapeutic keratoplasty, but topical azole antifungal agents such as voriconazole appear promising.
Purification and crystallization of a novel membrane‐anchored protein: the Schistosoma haematobium serpin

A unique serine-protease inhibitor (serpin) of the blood fluke S. haematobium has been crystallized. It is an antitrypsin with an unusual residue (phenylalanine) at its reactive center. Unlike any known member of this gene family, it is a membrane-anchored protein on the surface of the parasite. The location of this serpin and immunological response to the protein indicate that it may play a important role in host–parasite interaction. The crystals belong to the trigonal space group P3221 or P3121 with unit-cell parameters a = b = 64.7, c = 186.7 A, α = 90.0, β = 90.0, γ = 120.0°. There is one molecule per asymmetric unit and the crystals diffracted to 2.2 A.
Optimized linkage and quenching strategies for quantum dot molecular beacons.

Abstract Quantum dot (QD) molecular beacons were explored for sequence-specific DNA detection. The effectiveness of multiple linkage strategies and fluorescence quenchers were compared in hybridization-based assays. To compare linkage strategies, covalent amide linkage and streptavidin–biotin binding were used to link semiconductor QDs to molecular beacon DNA. Amide-linked beacons showed a 57% greater fluorescence increase than streptavidin-linked beacons when hybridized to 200 pmol of target DNA. The specificity of the molecular beacons, however, was similar for both linkage methods. Hybridization of both QD molecular beacons with non-complementary target DNA resulted in approximately 50% lower fluorescence intensity than hybridization with complementary DNA. The effectiveness of different quencher moieties was also evaluated. Iowa Black and 1.4 nm Nanogold-quenched molecular beacons exhibited approximately 2-fold greater fluorescence increases than dabcyl-quenched beacons when hybridized to complementary target. Specificity for target DNA was also confirmed through hybridization assays with non-complementary DNA. To provide insight into differences between the QD molecular beacons and the linkage strategies used, the hydrodynamic radius of each was measured. These measurements indicated that the larger radius of the streptavidin QDs (13.5 nm) than the carboxyl QDs (7 nm) could have a negative effect on FRET-based quenching for QD molecular beacons. These data outline the importance of choosing proper linkage methods and quencher moieties for creating high-quality QD molecular beacons.
Constraints on s -wave pairing in the Hubbard model

We present an exact identity between the on-site and the extended s-wave pairing amplitudes in the Hubbard model. We prove that the extended s-wave pairing amplitude vanishes identically at half filling for both signs of U. Away from half filling, the existence of an on-site s-wave pairing is a necessary and sufficient condition for the existence of an extended s-wave pairing. This result gives rise to constraints on the possible symmetries of the superconducting gap in the Hubbard model.
926-28 Ventricular Tachycardia After Inferior Wall Myocardial Infarction: Predominance of Basal Locations for Critical Slow Conduction Zones

Inter-patient similarities in coronary and ventricular anatomy may cause reentry circuit slow conduction zones (SCZ) to form in certain locations after myocardial infarction (MI). We assessed the location of reentry circuit SCZs identified using entrainment techniques during catheter mapping and ablation in 14 patients with an old inferior wall MI. The inferior wall was divided into 9 regions. Of 34 different ventricular tachycardias (VT) having a mean cycle length of 408 ± 82 msec, SCZs were identified in 21 (62%). At 18 of these 21 sites (86%), the SCZ was in a basal region near the mitral annulus (p l 0.01 vs all other regions). In 6 VTs, the SCZ extended into two regions. IN-SEP INF INF-LAT Total (27) BASAL 3 13 6 22 MID 1 2 0 3 APEX 0 2 0 2 SEP = septum, INF = inferior, LAT = lateral Conclusion The prevalence of SCZs near the base after inferior Mis suggest a possible role olthe mitral annulus in defining the margins olthe reentry circuit.
Chemistry of OClO in the Antarctic stratosphere: implications for bromine

Previous observations of OClO over the Antarctic obtained in 1986 are used to constrain the stratospheric abundance of bromine. The observed diurnal variation is consistent with the production of OClO via the reaction of ClO with BrO if the branching ratio to the BrCl channel is between 3.5 and 14 percent. Otherwise, an additional source in twilight is indicated. The present results suggest a stratospheric bromine concentration of 16 + or - 4 pptv, a value which is consistent with independent measurements.
Hypermedia Environments and Adaptive Instruction

Abstract The relevant professional literature is reviewed and discussed regarding the following salient issues: (1) hypermedia environments enable learner control; (2) this is reflected in individuals' navigational paths through network-based subject matter; (3) these student tracks can be captured in log files; and (4) this information can be used by artificially intelligent tutors to implement adaptive instruction. Assuming (1) most schools, colleges, universities, and corporations will eventually offer distributed students network-based instruction for particular refresher preparation and certain core courses, and (2) adaptive intelligent tutors are crucial components of course management systems, recommendations for research, development, and evaluation, extracted from the discussion, are made to appropriate sponsors, academic administrators, faculty members, training managers, and instructional developers, interested in realizing on-line learning.
Impact of Perforating on Well Performance and Cumulative Production

This study presents a simplified method to predict inflow performance of and cumulative production from selectively perforated wells in bounded reservoirs. The model first calculates the pseudo-skin for a fully perforated well penetrating a formation with only unit thickness. Then, perforation pseudo-skin is superimposed on a two-dimensional selectively open completed well model. Using the new model, a sensitivity study is carried out to identify the parameters controlling the well flow rate and total recovery. The sensitivity study includes the impact of shot density, perforation size and length, phasing angle, perforated length/formation thickness ratio, and the degree of formation damage around the wellbore and perforations.
Diallyl disulfide inhibits the proliferation of human tumor cells in culture

Diallyl disulfide (DADS), an oil-soluble organosulfur compound in processed garlic, was more effective in inhibiting the in vitro growth of human tumor cell lines: HCT-15 (colon), A549 (lung), and SK MEL-2 (skin) than isomolar quantities of the water-soluble compound S-allyl cysteine (SAC). Addition of DADS (100 microM) was cytostatic to all three cell lines. The importance of the allyl and the disulfide groups were revealed by the lack of a comparable depression in the growth of HCT-15 cells exposed to its saturated analogue, dipropyl disulfide (DPDS). Treatment with DADS also resulted in a dose-dependent increase in intracellular free calcium in cells. A dose-dependent decrease in the activity of calcium-dependent ATPase enzyme occurred in HCT-15 cells exposed to increasing quantities of DADS. A correlation (r = -0.975) was found between the intracellular free calcium levels and the Ca-ATPase activity in DADS-treated cells. These studies document that DADS, a constituent of garlic oil, is an effective inhibitor of the growth of human neoplastic cells. Alterations in calcium hemostasis are likely involved in the growth inhibition/cytotoxicity caused by DADS.
Privacy and Policy

Cet article etudie la politique d'information des Etats-Unis face au probleme du developpement des moyens de communication et de la protection de la vie privee. Il presente tout d'abord les mesures prises par la Constitution americaine, puis une definition de la notion de vie privee est proposee. Ensuite les besoins pour une politique generale pour la protection de la vie privee sont examinee
On Rota's problem of the explicit representation for umbral operators

Abstract Prof. Rota's problem on finding the explicit representation of an umbral operator is solved.
High—Monounsaturated Fat Diet for Diabetic Patients: Is it time to change the current dietary recommendations?

The study by Rasmussen et al. (1) and studies by Campbell et al. (2, this issue) and Lerman-Garber et al. (3, this issue) report on the beneficial effects of high-monounsamrated fat diets in comparison with high-carbohydrate diets in patients with non-insulin-dependent diabetes mellims (N1DDM). The study by Rasmussen et al. (1) reported improvement of glycemie control and lowering of blood pressure (BP) with a high-monounsaturated fat diet. Campbell et al. (2) describe practical ways to prescribe a high-monounsaturated fat diet to NIDDM patients for use at home and report improvement in glycemie control and plasma triglyceride levels. Lerman-Garber et al. (3) report lowering of plasma triglyceride levels with an avocado-based high-monounsaturated fat diet. These data generally confirm the results of previous studies (4-9) and further support the use of high-monounsaturated fat diets in diabetic patients.
Improving hydrogen isotope ratio measurements for on-line chromium reduction systems

Recent advances in on-line metal [U, Mn, Cr] reduction systems for the automated analysis of δDVSMOW in water and organic solvents greatly increases sample throughput. However, several sources of uncertainty are inherent in these systems, including analytical reproducibility, fractionation of reference gas in the inlet system, and memory effects, as well as error introduced during data normalization that must be quantified. A careful consideration of these sources of uncertainty suggests that accuracy to <1‰ may be difficult to achieve due to the combined effects of analytical error and uncertainty in the calibration of secondary laboratory standards. However, for internally consistent data sets, it may be possible to measure relative differences between samples at the ∼0.5‰ level or below. In addition to describing methods for data reduction, strategies for minimizing and managing uncertainty are presented along with a recipe for greatly increasing reactor life in Cr-reduction systems. Increased reactor life reduces consumable costs by a factor of 10. Copyright © 2001 John Wiley & Sons, Ltd.
Choosing between atmospheric pressure chemical ionization and electrospray ionization interfaces for the HPLC/MS analysis of pesticides.

An evaluation of over 75 pesticides by high-performance liquid chromatography/mass spectrometry (HPLC/MS) clearly shows that different classes of pesticides are more sensitive using either atmospheric pressure chemical ionization (APCI) or electrospray ionization (ESI). For example, neutral and basic pesticides (phenylureas, triazines) are more sensitive using APCI (especially positive ion). While cationic and anionic herbicides (bipyridylium ions, sulfonic acids) are more sensitive using ESI (especially negative ion). These data are expressed graphically in a figure called an ionization-continuum diagram, which shows that protonation in the gas phase (proton affinity) and polarity in solution, expressed as proton addition or subtraction (pKa), is useful in selecting APCI or ESI. Furthermore, sodium adduct formation commonly occurs using positive ion ESI but not using positive ion APCI, which reflects the different mechanisms of ionization and strengthens the usefulness of the ionization-continuum diagram...
New a-Si:H photo-detectors for long-term charge storage

Using the high light absorption properties of amorphous silicon, we developed a new device configuration that can detect photons and store the induced charges for relatively long time. This device, coupled to a scintillator such as CsI(Tl) in an array form, could be used as a scintillation camera, or for long-term photo-detection such as radionuclide labeled chromatography. The detector has a simple sandwich structure consisting of a scintillator followed by a top metal layer, p-i-n layers of hydrogenated amorphous silicon (a-Si:H), a second metal layer, a thin insulating layer and a bottom metal layer. The electron-hole pairs generated in the i-layer by the interaction with the incident light will be separated by the imposed electric field and be stored in the central metal-insulator interface. Readout will be done by switching the external bias to ground after the storage time, which depends on the needs for the specific application. Prototype devices were fabricated and tested. The performances of the devices were analyzed in connection with the storage time and the background signal produced by the thermally generated charges.
The synthesis and characterization of neptunium hydroxysulfate, Np(OH)2SO4

Abstract Neptunium (IV) hydroxysulfate, Np(OH) 2 SO 4 , was synthesized using hydrothermal techniques. The X-ray powder diffraction pattern indicates that the compound is isomorphous with the Th(IV) and U(IV) analogs. Cell constants for the three compounds clearly show the effects of the actinide contraction. Visible and near-ir spectra are consistent with the presence of Np(IV) and are compared to spectra of Np(IV) in acidic solution. The ir spectrum contains bands which are assigned to the hydroxy and sulfate groups.
Plastics, Pesticides and PBDEs: Endocrine Disruption and Developmental Disabilities

Many chemicals to which humans are regularly exposed interfere with normal endocrine (hormonal) function, including critical mechanisms underlying brain development. While it is methodologically difficult to directly associate chemical exposures with subsequent manifestations of developmental disabilities, ample evidence exists to justify concern and precautionary action to reduce or eliminate exposures. In this article, we review the literature concerning the endocrine disruptive properties of three commonly encountered classes of substances, plastics, pesticides, and flame retardants (PBDEs), and the mechanisms by which they may be contributing to the apparent increase in prevalence of developmental disabilities. We urge professionals working in disabilities fields to advocate for stronger regulation and public education regarding the toxic properties of such materials.
Formation of molten metal films during metal-on-metal slip under extreme interfacial conditions

Abstract The present paper describes results of plate-impact pressure-shear friction experiments conducted to study time-resolved growth of molten metal films during dry metal-on-metal slip under extreme interfacial conditions. By employing tribo-pairs comprising hard tool-steel against relatively low melt-point metals such as 7075-T6 aluminum alloys, interfacial friction stress ranging from 100 to 400 MPa and slip speeds of approximately 100 m / s have been generated. These relatively high levels of friction stress combined with high slip-speeds generate conditions conducive for interfacial temperatures to approach the melting point of the lower melt point metal (Al alloy) comprising the tribo-pair. A Lagrangian finite element code is developed to understand the evolution of the thermo-mechanical fields and their relationship to the observed slip response. The code accounts for dynamic effects, heat conduction, contact with friction, and full thermo-mechanical coupling. At temperatures below the melting point the material is described as an isotropic thermally softening elastic-viscoplastic solid. For material elements with temperatures in excess of the melt point a purely Newtonian fluid constitutive model is employed. The results of the hybrid experimental-computational study provides new insights into the thermoelastic–plastic interactions during high speed metal-on-metal slip under extreme interfacial conditions. During the early part of frictional slip the coefficient of kinetic friction is observed to decrease with increasing slip velocity. During the later part transition in interfacial slip occurs from dry metal-on-metal sliding to the formation of molten Al films at the tribo-pair interface. Under these conditions the interfacial resistance approaches the shear strength of the molten aluminum alloy under normal pressures of approximately 1– 3 GPa and shear strain rates of ∼10 7 s −1 . The results of the study indicate that under these extreme conditions molten aluminum films maintain a shearing resistance as high as 100 MPa . Scanning electron microscopy of the slip surfaces reveal molten aluminum to be smeared on the tribo-pair interface. Knoop hardness measurements in 7075-T6 Al alloy at various depths from the slip interface indicate that the hardness increases approximately linearly with depth and reaches a plateau at approximately 40 μm from the surface.
Effect of pressure on ore mineral solubilities under hydrothermal conditions

Experimental studies were conducted at elevated pressures and temperatures on the combined solubilities of iron, zinc, and lead sulfides in chloride solutions buffered in pH by a silicate assemblage of quartz monzonite composition plus added muscovite, and buffered in/s2 and/o2 by the assemblage pyrite-pyrrhotite-magnetite. Major controls on base metal concentration are temperature, total chloride, and pressure. Higher temperature and higher chloride concentration favor higher metal solubilities as expected, but the pressure effect is opposite to that generally expected and is of considerable importance to the problem of ore mineral transport. At 500 °C, 0.5 kbar, and 1 m total chloride, Fe, Zn, and Pb solubilities were 8500, 4300, and 8700 ppm, respectively, whereas at 1 kbar they were 4200, 2400, and 2600 ppm, and at 2 kbar, 1700, 800, and 1200 ppm. The experimental results thus indicate that the metals could be carried over long distances on a decreasing pressure gradient so long as the temperature decreases were not sufficient to significantly offset the pressure effect. Such a condition could be approximated by a near-adiabatic transport cooling path. Such a condition is probably common geologically, especially for hydrothermal processes involving fairly deep-seated sources of heat and mineral components.