cssi/SciSciGPT-SciSciNet huggingface dataset:
Synthesis and crystallization of hybrid spherical colloids composed of polystyrene cores and silica shells.

The Stober method has been adopted to prepare hybrid core-shell particles by coating the surfaces of monodisperse polystyrene beads with uniform silica shells. Polystyrene beads with diameters in the range of 0.1-1.0 microm have been successfully demonstrated for use with this process, and the thickness of the silica coating could be controlled in the range of 50-150 nm by adjusting the concentration of tetraethoxysilane, the deposition time, or both. The morphology and surface smoothness of the deposited silica were found to strongly depend on a number of parameters such as the surface functional groups on the polymer beads, the pH value of the medium, and the deposition time. Hollow spheres made of silica could be obtained by selectively removing the polymer cores via calcination in air at an elevated temperature or by wet etching with toluene. These core-shell colloids were also explored as building blocks to fabricate long-range ordered lattices (or colloidal crystals) that exhibited stop bands different from those assembled from spherical colloids purely made of either polystyrene or silica.
The molecular paramagnetic moment in the short time limit

Abstract We discuss the paramagnetic moment of a molecule, such as oxygen or nitric oxide, considered over the time span of a molecular collision. Detailed gas-phase measurements of proton spin-lattice relaxation in paramagnetically adulterated methane show that the paramagnetic moment is not, in general, a constant of the motion over the time scale of the interaction of the methane and the paramagnetic molecule. The time correlation of the paramagnetic moment over this time period is especially dependent on the coupling of the internal orbital and spin angular momentum of the molecule with molecular rotation. In the case of oxygen, S is a good quantum number and the electron spins are coupled to rotation only via the electron-electron dipolar coupling. Nitric oxide, by contrast, is a molecule which fits Hund's case A. Here the paramagnetic moment vector precesses about the J axis during the time period of vie collision, resulting in a partial y averaged magnetic moment. These considerations enable us to explain the experimental temperature dependence of the spin-lattice relaxation time T1 of the paramagnetically adulterated methane system, as well as the fact that oxygen is about eight times as effective as nitric oxide in relaxing the methane protons.
Rearrangement of acyloxyoxiranes : a revised structure for the oxidation product of 5α -androst-16-ene-3α-,17-diol 3-benzoate 17-acetate

Abstract During the oxidation of conjugated enones to α-acyloxyoxiranes by m-chloroperbenzoic acid, the preferred sequence is epoxidation followed by Baeyer-Villiger oxidation. Rearrangement of acyloxyoxiranes to α-acyloxyketones, in situ, was observed. The α-ketoacetate structure assigned previously to the m-CPBA oxidation product of 5α-androst-16-ene-3α,17-diol 3-benzoate 17-acetate, has been revised to an acyloxyoxirane structure based on spectroscopic and X-ray diffraction data.
Identification of lipid aggregate structures on TiO2 surface using headgroup IR bands.

Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy was used to study the nature of the dipalmitoylphosphatidylcholine (DPPC) aggregated structures adsorbed on TiO2. DPPC molecules were assembled on TiO2 using Langmuir−Blodgett (LB) deposition methods or by directly flowing the DPPC liposome solution across the TiO2-coated ATR crystal. We found that there is a direct correlation between the intensity and frequency position of the zwitterionic headgroup IR bands and the nature of LB films. Specifically, we have shown that the bands due to PO2- modes are sensitive to changes in the degree of hydration of the LB films and that the symmetric deformation vibrational mode (δs +N−CH3) is sensitive to interaction with oppositely charged surface sites. Using this information, we found that the liposomes adsorbed on TiO2 remain intact as vesicles and that the vesicles are stable and not removed in flowing water. We have also shown that the antisymmetric deformation vibrational (δas +N−CH3...
Influence of glucose on amine release from rat corpus striatum.

Abstract The influence of glucose on release of tritiated α-methyl-m-tyramine (3H-MMTA), a false dopaminergic transmitter, from rat corpus striatum was studied in vitro. K+, in submaximal releasing concentrations (27mM) produced much greater release when glucose was omitted from the washout medium. Inclusion of 2-deoxyglucose along with glucose gave results not different from experiments in which glucose was omitted. Amphetamine also released more 3H-MMTA in the absence of glucose. Thus, glucose influenced release by two agents with entirely different modes of action. It is suggested that this action of glucose might be fundamental to the handling of transmitters by nerve terminals.
Reviving the Swan, Extending the Curse of Methuselah, or Adhering to the Kevorkian Ethic?

Methuselah, it is said, lived 969 years. His state of health at death is not revealed. It can only be surmised that he was surely not robust and, no doubt, was subject to all of the infirmities of old age and the tragic indignities associated with senility.Jonathan Swift captured well the “curse” of immortality when, in Gulliver's Travels, he created a group of individuals, the Struldbrugs, who, when encountered, dulled what had heretofore been an appetite for perpetual life. The Struldbrugs were allowed to be born totally exempt from the “calamity of human Nature,” in that their minds were free “and disingaged (sic), without the Weight and De pression of Spirits caused by the continued Apprehension of Death.” They were thus condemned “to a perpetual continuance in the World.” In his travels, Gulliver found some Struldbrugs well over 1,000 years old.
Arteriographic assessment of patency of the inferior alveolar artery and its relevance to alveolar atrophy

Patency of the inferior alveolar artery was investigated on 84 patients who had undergone selective external carotid angiography with digital subtraction. Patency of the artery was lost earlier in males than females, but the presence or absence of teeth did not appear to affect the outcome. The artery was visualized less well on patients with medical conditions that may predispose to early or excessive atherosclerotic disease.
Adult thymectomy results in loss of T-dependent mitogen response in mouse spleen cells.

THERE is overwhelming evidence that murine thymocytes represent a heterogeneous population of cells that can be divided into discrete subpopulations on the basis of surface antigen markers1,2, drug sensitivity3, physical characteristics4,5 and responsiveness to mitogens6. There is some indication that a similar heterogeneity with regard to biological function exists within the peripheral thymus-derived (T) lymphocyte population (reviewed in refs 7–9). Several investigators have shown that thymectomy of young adult mice reveals a differential sensitivity of several T-cell activities to this surgical procedure and suggested the existence of T-cell subsets with different life spans7–9. Therefore we investigated the response to PHA and concanavalin A in adult thymectomised (ATX) mice to determine if responsiveness to these mitogens could be attributed similarly to subpopulations of T cells.
Readability of self‐report clinical outcome measures

Because the validity of data obtained from self-report clinical outcome measures depends upon the ability of the client to comprehend the inventories, readability was assessed for five frequently employed measures: Beck Depression Inventory, Integra Outpatient Tracking Assessment, MOS 36-Item Short-Form Health Survey, Social Adjustment Scale-Self Report, and Symptoms Checklist-90-Revised. The Flesch Reading Ease (RE) formula and a Flesch abstraction formula were applied. The measures are generally shown to be useful for patients with an eighth or ninth grade education, suggesting that outcome researchers must choose only those measures appropriate to the educational background of their clients.
Cytotoxicity of monofunctional alkylating agents. Methyl methanesulfonate and methyl-n'-nitro-n-nitrosoguanidine have different mechanisms of toxicity for 10t1/2 cells.

Abstract N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) and methyl methanesulfonate (MMS) are directly active alkylating agents that methylate cellular macromolecules by SN1 and SN2 mechanisms, respectively. These two chemicals produce similar types of alkylation products in DNA and a similar level of total alkylations on a molar basis, but strikingly different proportions of alkylations of ring oxygen atoms of purines and pyrimidines. Because of this attribute, they have been used in combination to attempt to determine which types of alkylation products are responsible for mutation, transformation, and toxicity. Studies have suggested that the mutation rates produced by these and similar chemicals in cells surviving toxicity correlate well with the number of methyl adducts at the O6 position of guanine, but that cytotoxicity (reduced colony-forming efficiency) does not correlate with any single adduct or with the total level of alkylation of DNA. In this study we have investigated the cytotoxic mechanisms of MNNG and MMS in synchronized 10 T 1 2 cells, using colony-forming ability as a measure of toxicity. Both MNNG and MMS cause dose-dependent reduction in the ability of 10 T 1 2 cells to produce colonies of more than 50 cells after 2 weeks in culture. MNNG is about 100-fold more toxic than MMS on a molar basis. As indicated by the inability of cells to exclude trypan blue, MMS kills a fraction of the population of treated 10 T 1 2 cells after a 30-min exposure; the fraction of cells that excludes trypan blue is correlated with dose of MMS and with colony-forming efficiency. Neither the fraction of cells that is permeable to trypan blue nor the relative colony-forming efficiency is affected by the phase of the cycle when 10 T 1 2 cells are treated with MMS. Furthermore, MMS toxicity for 10 T 1 2 cells is not potentiated by caffeine, MMS treatment does not delay progress of S phase, and cells that survive acute membrane toxicity complete the cell cycle without significant delay. In contrast, MNNG treatment produces toxicity that is maximal when 10 T 1 2 cells are exposed during the S phase and the effect of potentiated by caffeine. MNNG treatment delays DNA replication and this delay is reversed by caffeine. In sharp contrast to 10 T 1 2 cells treated with MMS. MNNG-treated cells are not made permeable to trypan blue, but are blocked in their ability to proliferate. These observations indicate that MNNG and MMS kill 10 T 1 2 cells by drastically different mechanisms, MNNG producing toxicity mainly by preventing chromosome replication and MMS producing toxicity mainly by damaging cell membranes.
Protective Immunity to Vaccinia Virus Induced by Vaccination with Multiple Recombinant Outer Membrane Proteins of Intracellular and Extracellular Virions

Infectious intracellular and extracellular forms of vaccinia virus have different outer membrane proteins, presenting multiple targets to the immune system. We investigated the immunogenicity of soluble forms of L1, an outer membrane protein of the intracellular mature virus, and of A33 and B5, outer membrane proteins of the extracellular enveloped virus. The recombinant proteins, in 10-μg amounts mixed with a Ribi- or saponin-type adjuvant, were administered subcutaneously to mice. Antibody titers to each protein rose sharply after the first and second boosts, reaching levels that surpassed those induced by percutaneous immunization with live vaccinia virus. Immunoglobulin G1 (IgG1) antibody predominated after the protein immunizations, indicative of a T-helper cell type 2 response, whereas live vaccinia virus induced mainly IgG2a, indicative of a T-helper cell type 1 response. Mice immunized with any one of the recombinant proteins survived an intranasal challenge with 5 times the 50% lethal dose of the pathogenic WR strain of vaccinia virus. Measurements of weight loss indicated that the A33 immunization most effectively prevented disease. The superiority of protein combinations was demonstrated when the challenge virus dose was increased 20-fold. The best protection was obtained with a vaccine made by combining recombinant proteins of the outer membranes of intracellular and extracellular virus. Indeed, mice immunized with A33 plus B5 plus L1 or with A33 plus L1 were better protected than mice immunized with live vaccinia virus. Three immunizations with the three-protein combination were necessary and sufficient for complete protection. These studies suggest the feasibility of a multiprotein smallpox vaccine.
Evaluating army geospatial data collection tools

During the conflicts in Iraq and Afghanistan, there were thousands of different types of equipment delivered to Army units to support their efforts. These “rapidly fielded” systems did not follow the standard Department of Defense procurement process to become what is termed a “Program of Record”, or PoRs, meaning a program which has a funding stream to continue fielding and support. Now that the war effort is winding down, these systems will either be terminated or become PoR. One such system is the Buckeye system. This system provides very high-definition 3D photo capabilities which can provide Army units with near real-time pictures of the terrain which they are about to walk through or, in the case of helicopters, land on. To become a Program of Record, the Army must determine if the system provides the most cost-beneficial solution. In this paper, we evaluate the value of systems which can be used to evaluate terrain data for Army units using a process known as the Systems Decision Process.
The AmeriFlux Data Activity and Data System: An Evolving Collection of Data Management Techniques, Tools, Products and Services

Abstract. The Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL), USA has provided scientific data management support for the US Department of Energy and international climate change science since 1982. Among the many data archived and available from CDIAC are collections from long-term measurement projects. One current example is the AmeriFlux measurement network. AmeriFlux provides continuous measurements from forests, grasslands, wetlands, and croplands in North, Central, and South America and offers important insight about carbon cycling in terrestrial ecosystems. To successfully manage AmeriFlux data and support climate change research, CDIAC has designed flexible data systems using proven technologies and standards blended with new, evolving technologies and standards. The AmeriFlux data system, comprised primarily of a relational database, a PHP-based data interface and a FTP server, offers a broad suite of AmeriFlux data. The data interface allows users to query the AmeriFlux collection in a variety of ways and then subset, visualize and download the data. From the perspective of data stewardship, on the other hand, this system is designed for CDIAC to easily control database content, automate data movement, track data provenance, manage metadata content, and handle frequent additions and corrections. CDIAC and researchers in the flux community developed data submission guidelines to enhance the AmeriFlux data collection, enable automated data processing, and promote standardization across regional networks. Both continuous flux and meteorological data and irregular biological data collected at AmeriFlux sites are carefully scrutinized by CDIAC using established quality-control algorithms before the data are ingested into the AmeriFlux data system. Other tasks at CDIAC include reformatting and standardizing the diverse and heterogeneous datasets received from individual sites into a uniform and consistent network database, generating high-level derived products to meet the current demands from a broad user group, and developing new products in anticipation of future needs. In this paper, we share our approaches to meet the challenges of standardizing, archiving and delivering quality, well-documented AmeriFlux data worldwide to benefit others with similar challenges of handling diverse climate change data, to further heighten awareness and use of an outstanding ecological data resource, and to highlight expanded software engineering applications being used for climate change measurement data.
Evaluation of intervention to prevent hypomagnesemia in cervical cancer patients receiving combination cisplatin and radiation treatment.

The purpose of this study was to evaluate the impact of increasing the magnesium (Mg2+) supplementation in the pre- and posthydration of patients receiving cisplatin plus radiation (CisXRT) to prevent chemotherapy-induced hypomagnesemia (CIH) events. The study was conducted on newly diagnosed cervical cancer patients receiving CisXRT. The first prospective intervention to prevent CIH was to increase the pre- and posthydration Mg2+ from 1 to 2 g. After completion of the first intervention, the analysis demonstrated the persistent occurrence of CIH on cycle 3, and later, a second intervention was implemented to increase Mg2+ to 3 g in the pre- and posthydration. Patients that failed to complete at least five cycles or received cisplatin in combination with another chemotherapy regimen were excluded from the study. Baseline group included 70 patients that had received CisXRT prior to any changes in magnesium supplementation. There were 62.8% (44/70) and 32.6% (22/70) of patients with episodes of CIH in the baseline and first intervention groups, respectively (P = 0.007). In the second intervention group, a 49.6% decrease in the total number of episodes compared to control group was observed. Patients in the second intervention group showed a 100% improvement incidence of persistent CIH over the two other cohorts (P = 0.001). The increase of Mg2+ to 2 g for the initial two cycles and then to 3 g with the third cycle of CisXRT therapy prevented episodes of CIH and decreased associated treatment delays.
Noun phrase structure in German-English codeswitching: Variation in gender assignment and article use

This article investigates the construction of the grammatical frame in codeswitching in terms of the roles played by the two languages in contact, referred to here as the Matrix Language(ML) and Embedded Language(EL). In “classic” codeswitching, the ML sets the grammatical frame; in addition, however, we claim that the ML frame may be synchronically variable and may converge toward the EL with increased duration of bilingualism. This process has been called an ML turnover, and these data show the roots of this development. We present data from German-English codeswitching on grammatical gender assignment and article use in noun phrases. These features have been chosen for analysis because they are aspects of the noun phrase in which English and German exhibit structural differences, and it is important to study how bilinguals deal with the lack of congruence in codeswitching structures. For grammatical gender assignment, the ML(in this case, German) determines the codeswitching structure, yet this does no...
Frequency and Content of Chat Questions by Time of Semester at the University of Central Florida: Implications for Training, Staffing and Marketing

ABSTRACT The more than 4,000 “chats” received by the University of Central Florida's (UCF) Ask-A-Librarian digital reference service are the subject of this practitioner-based, descriptive case study. Question content from chats received during four semesters between January 2005 and May 2006 are categorized and plotted, by semester, to show the number of questions received in each question category. The study seeks to provide a baseline of descriptive statistics for the UCF digital reference service and to address gaps in the literature about the manner in which patrons are using digital reference services. Further, awareness of question topics can contribute to effective decisions about training and staffing requirements and marketing of services.
Quinocarmycin Analog DX-52-1 Inhibits Cell Migration and Targets Radixin, Disrupting Interactions of Radixin with Actin and CD44

In the course of screening for new small-molecule modulators of cell motility, we discovered that quinocarmycin (also known as quinocarcin) analog DX-52-1 is an inhibitor of epithelial cell migration. While it has been assumed that the main target of DX-52-1 is DNA, we identified and confirmed radixin as the relevant molecular target of DX-52-1 in the cell. Radixin is a member of the ezrin/radixin/moesin family of membrane-actin cytoskeleton linker proteins that also participate in signal transduction pathways. DX-52-1 binds specifically and covalently to the C-terminal region of radixin, which contains the domain that interacts with actin filaments. Overexpression of radixin in cells abrogates their sensitivity to DX-52-1's antimigratory activity. Small interfering RNA-mediated silencing of radixin expression reduces the rate of cell migration. Finally, we found that DX-52-1 disrupts radixin's ability to interact with both actin and the cell adhesion molecule CD44.
Religion and United States Physicians’ Opinions and Self-Predicted Practices Concerning Artificial Nutrition and Hydration

This study surveyed 1,156 practicing US physicians to examine the relationship between physicians’ religious characteristics and their approaches to artificial nutrition and hydration (ANH). Forty percent of physicians believed that unless a patient is imminently dying, the patient should always receive nutrition and fluids; 75 % believed that it is ethically permissible for doctors to withdraw ANH. The least religious physicians were less likely to oppose withholding or withdrawing ANH. Compared to non-evangelical Protestant physicians, Jews and Muslims were significantly more likely to oppose withholding ANH, and Muslims were significantly more likely to oppose withdrawing ANH.
The Core Protein of the Chondroitin Sulfate Proteoglycan Phosphacan Is a High-affinity Ligand of Fibroblast Growth Factor-2 and Potentiates Its Mitogenic Activity

Using a radioligand binding assay we have demonstrated that phosphacan, a chondroitin sulfate proteoglycan of nervous tissue that also represents the extracellular domain of a receptor-type protein tyrosine phosphatase, shows saturable, reversible, high-affinity binding (Kd approximately 6 nM) to fibroblast growth factor-2 (FGF-2). Binding was reduced by only approximately 35% following chondroitinase treatment of the proteoglycan, indicating that the interaction is mediated primarily through the core protein rather than the glycosaminoglycan chains. Immunocytochemical studies also showed an overlapping localization of FGF-2 and phosphacan in the developing central nervous system. At concentrations of 10 microg protein/ml, both native phosphacan and the core protein obtained by chondroitinase treatment potentiated the mitogenic effect of FGF-2 (5 ng/ml) on NIH/3T3 cells by 75-90%, which is nearly the same potentiation as that produced by heparin at an equivalent concentration. Although studies on the role of proteoglycans in mediating the binding and mitogenic effects of FGF-2 have previously focused on cell surface heparan sulfate, our results indicate that the core protein of a chondroitin sulfate proteoglycan may also regulate the access of FGF-2 to cell surface signaling receptors in nervous tissue.
Neuroimaging experience in pediatric Horner syndrome

Background Horner syndrome in children is rare. The frequency and spectrum of malignancy as the cause of Horner syndrome in children remains unclear. Also unclear is whether the imaging work-up should include the entire oculo-sympathetic pathway or should be more targeted. In addition, the value of cross-sectional angiographic imaging in Horner syndrome is uncertain.
Opening doors to tourism planning in the 21st century: A practical and scholarly view© Ontario Research Council on Leisure

(2007). Opening doors to tourism planning in the 21st century: A practical and scholarly view© Ontario Research Council on Leisure. Leisure/Loisir: Vol. 31, No. 2, pp. 375-382.
Doping Uric Acid Crystals. 1. Uric Acid Dihydrate

The crystallization of uric acid dihydrate (UAD) from model supersaturated aqueous solutions containing 21 different molecular dye probes and 11 inorganic salts was investigated. UAD crystals grown at room temperature were found to include low concentrations (0.01−0.42%) of cationic and neutral dyes but not anionic dyes. From dilute dye solutions, a preference for inclusion in either {011} or {102} growth sectors was exhibited for some dyes while others showed little specificity. At higher dye concentrations, inclusion generally increased but specificity tended to diminish. Crysoidine G was exceptional in that over a broad range of solution concentrations, it was consistently and exclusively included on growth hillocks located in {011} sectors. Most dye-doped UAD crystals also exhibited morphological changes, namely the development of {210} faces, which are typically absent in pure UAD crystals. UAD grown from salt solutions showed inclusion of Na+, K+, and Mg2+ ions in concentrations similar to dyes; how...
Reaction-Diffusion Model for A + A Reaction

We formulate an approach to the A + A {yields} products reaction that is based on a reaction-diffusion equation frequently used for the A + B problem but requires an appropriate generalization for the A + A problem. This approach leads naturally to the proportionality of the rate of the reaction to the pair correlation function evaluated at r = a, where a is the diameter of the reacting particles. In other words, the reaction rate is proportional to the probability that two A particles are sufficiently close. We also present numerical simulations in one and two dimensions in order to check our predictions. We confirm the well-known anomalous rate law in one dimension (the anomalies are marginal in two dimensions) and the proportionality of the reaction rate to the two-particle correlation function. Our simulations show that the rate of the reaction is indeed determined entirely by the spatial distribution of a very small shell of particles around a given reactant particle. Anomalous kinetics is a direct reflection of the deviation of the spatial distribution of this small shell from a random configuration. We also present simulation results that confirm the predicted distance and time scaling of the pair correlationmore » function in one dimension. 92 refs., 3 figs.« less
Peer Popularity and Peer Communication Patterns: Hyperactive versus Active but Normal Boys.

Classroom peer perceptions of 18 teacher-nominated hyperactive and 18 teacher-nominated active but normal elementary school-age boys, as revealed in two sociometric measures (Bower's Class Play, like-dislike nomination), were compared. Results indicated that hyperactives were significantly different from actives on all sociometric measures in that they were perceived more negatively. Peer communication patterns also were assessed. The communicative content, communicative quality, and attention to task instructions of hyperactive boys were compared to those of comparison boys. Limited support was found for the earlier finding that hyperactive boys were less likely than comparison boys to modulate behavior in response to changing external cues and to respond to subtle social learning opportunities. The communication task was found to be highly engaging for both groups of boys, and results suggest that hyperactive children may not lack the interpersonal skills necessary for referential communication, although they may be unable to use them consistently in all settings. The need to continue the study of peer relations of hyperactive children in naturalistic settings is stressed.
Hierarchical disk sharing for multimedia systems

Systems that use or serve multimedia data require timely access to data on hard drives. To ensure adequate performance users must either prevent overload of disk resources, or use real-time algorithms that rely on intricate knowledge of disk internals to meet deadline requirements. We have developed Hierarchical Disk Sharing (HDS) to allow disks to be fully utilized while sustaining a bandwidth reservation, without requiring detailed knowledge of the drive internals. HDS uses a hierarchy of token bucket filters to isolate disk access among clients and groups of clients, and to allow for reclaiming of unused bandwidth. We discuss the design of HDS and present our implementation in a Linux block device driver, demonstrating the effectiveness (and limitations) of this approach.
Influence of urbanization on riparian forest diversity and structure in the Georgia Piedmont, US

Riparian forests are increasingly threatened by urban expansion and land use change worldwide. This study examined the relationships between landscape characteristics and woody plant diversity, structure, and composition of small order riparian corridors along an urban-rural land use gradient in the Georgia Piedmont, US. Riparian plant diversity, structure, and composition were related to landscape metrics and land use. Species richness was negatively associated with impervious surfaces and landscape diversity, and positively associated with forest cover and largest forest patch index. Shannon species diversity was strongly related to the biomass of non-native species, especially for the regeneration layer. Urban sites were characterized by high richness of non-native and pioneer species. Developing sites were dominated by the non-native shrub, Ligustrum sinense Lour., and several native overstory trees, mainly Acer negundo L. While agricultural and managed forest sites were composed of ubiquitous species, unmanaged forest sites had a structurally distinct midstory indicative of reduced disturbance. Urban and agricultural land uses showed decreased native stem densities and signs of overstory tree regeneration failure. Results from this study highlight the impact of the surrounding landscape matrix upon riparian forest plant diversity and structure.
T2‐shortening by strongly magnetized spheres: A chemical exchange model†

It is shown that a chemical exchange model can reproduce nuclear magnetic relaxation caused by diffusion of water molecules near strongly magnetized particles. The agreement is based on the similarity (but not equivalence) of the respective “visit-limiting” mechanisms in the echo-limited regime. The model leads to a single equation that predicts relaxation behavior in both the motional-averaging and visit-limited regimes. When combined with the static-dephasing regime equation, the result is a simple theory (for spheres) that covers the entire range of diffusion times. Magn Reson Med 47:388–391, 2002. Published 2002 Wiley-Liss, Inc.
The False Dasein: From Heidegger To Sartre and Psychoanalysis1

The analysis of Dasein's struggle for authenticity will be the main focus of this article. By virtue of Dasein's ontological predispositions, selfhood is subjected to inauthentic existential modalities already constitutive of its Being. In the case of the false Dasein, fallenness is exacerbated in that Dasein constricts its comportment primarily to the modes of the inauthentic, thereby abdicating its potentiality-for-Being. The false Dasein results from ontical encounters within pre-existing deficient ontological conditions of Being-in-the-world that are thrust upon selfhood as its facticity. These deficient ontological structures predispose Dasein to develop intrapsychic psychological deficits that further contribute to Dasein's false existence. Through the medium of Heidegger's existential ontology, Sartrean bad faith, and psychoanalysis, I will demonstrate that the throes of selfhood encompass a dialectical course meandering through experiential modes of authenticity and falsehood, in which this very process itself is an authentic enterprise, that is, it is the necessary constitutional structure of Dasein itself as Being-toward-becoming its possibilities.
Transformation with Oncogenic Ras and the Simian Virus 40 T Antigens Induces Caspase-Dependent Sensitivity to Fatty Acid Biosynthetic Inhibition

Oncogenesis is frequently accompanied by the activation of specific metabolic pathways. One such pathway is fatty acid biosynthesis, whose induction is observed upon transformation of a wide variety of cell types. Here, we explored how defined oncogenic alleles, specifically the simian virus 40 (SV40) T antigens and oncogenic Ras12V, affect fatty acid metabolism. Our results indicate that SV40/Ras12V-mediated transformation of fibroblasts induces fatty acid biosynthesis in the absence of significant changes in the concentration of fatty acid biosynthetic enzymes. This oncogene-induced activation of fatty acid biosynthesis was found to be mammalian target of rapamycin (mTOR) dependent, as it was attenuated by rapamycin treatment. Furthermore, SV40/Ras12V-mediated transformation induced sensitivity to treatment with fatty acid biosynthetic inhibitors. Pharmaceutical inhibition of acetyl-coenzyme A (CoA) carboxylase (ACC), a key fatty acid biosynthetic enzyme, induced caspase-dependent cell death in oncogene-transduced cells. In contrast, isogenic nontransformed cells were resistant to fatty acid biosynthetic inhibition. This oncogene-induced sensitivity to fatty acid biosynthetic inhibition was independent of the cells' growth rates and could be attenuated by supplementing the medium with unsaturated fatty acids. Both the activation of fatty acid biosynthesis and the sensitivity to fatty acid biosynthetic inhibition could be conveyed to nontransformed breast epithelial cells through transduction with oncogenic Ras12V. Similar to what was observed in the transformed fibroblasts, the Ras12V-induced sensitivity to fatty acid biosynthetic inhibition was independent of the proliferative status and could be attenuated by supplementing the medium with unsaturated fatty acids. Combined, our results indicate that specific oncogenic alleles can directly confer sensitivity to inhibitors of fatty acid biosynthesis. IMPORTANCE Viral oncoproteins and cellular mutations drive the transformation of normal cells to the cancerous state. These oncogenic alterations induce metabolic changes and dependencies that can be targeted to kill cancerous cells. Here, we find that the cellular transformation resulting from combined expression of the SV40 early region with an oncogenic Ras allele is sufficient to induce cellular susceptibility to fatty acid biosynthetic inhibition. Inhibition of fatty acid biosynthesis in these cells resulted in programmed cell death, which could be rescued by supplementing the medium with nonsaturated fatty acids. Similar results were observed with the expression of oncogenic Ras in nontransformed breast epithelial cells. Combined, our results suggest that specific oncogenic alleles induce metabolic dependencies that can be exploited to selectively kill cancerous cells.
MATS: a rapid and efficient method for the development of microsatellite markers from YACs

In this report, we describe the successful application of a rapid and efficient procedure, based on subtractive hybridization and PCR amplification, for generating microsatellite-based markers directly from yeast artificial chromosomes (YACs). This strategy, termed MATS (marker addition through subtraction), exploits the fact that the only difference between a yeast host strain harboring a YAC and the host strain alone is the artificial chromosome. Given the low complexity of the yeast genome and relatively large target size presented by a YAC, only a single round of subtraction is required before amplification of the target sequences (YAC) and cloning into a plasmid vector for further analysis. Several key steps have been designed to achieve optimal subtraction and to obtain preferential amplification and recovery of the target sequences. Methods for efficient construction of small insert libraries and rapid, nonradioactive screening have also been integrated into the protocol. Using a 750-kb YAC as a target, we identified a minimum of 14 unique microsatellite containing clones, leading to the development of 12 polymorphic STSs (sequence-tagged sites). These new markers will facilitate the genetic localization of targeted locus and allow the accurate ordering by STS content mapping of a cloned contig spanning the interval. In addition to the utility of this approach in positional cloning, this strategy may provide an approach for filling gaps in the emerging genetic maps.
Kinetics of lacrimal secretion in normal human subjects

A novel technique was used to study the time course of lacrimation in normal human subjects with and without the use of topical anesthetic. The Schirmer technique was modified to eliminate evaporation, to improve absorption capacity, and to allow the determination of the length of paper strip wetted as a function of time. By the use of a theoretical model, the wetting curve thus obtained could be analyzed and basic secretion parameters characteristic of lacrimation kinetics were obtained. Fourteen adult females and six adult males between the ages of 21 and 47 years were included in the study.All the eyes examined exhibited essentially the same type of tear secretion kinetics. Initially, the lacrimation occurred at a high rate which then exponentially diminished to a final, lower value. This exponential cycle of secretion pattern could occur repeatedly during the time of measurement and was not qualitatively altered by the use of topical anesthesia. In addition to the time dependence of wetted length, we ...
A Tradeoff between Safety and Liveness for Randomized Coordinated Attack

We studyrandomized, synchronousprotocols for coordinated attack. Such protocols trade off the number of rounds (N), the worst-case probability of disagreement (U), and the probability that all generals attack (L). We prove a nearly tight bound on the tradeoff between L andU(L/U?N) for astrongadversary that destroys any subset of messages. Our techniques may be useful for other problems that allow a non-zero probability of disagreement
Bilirubin metabolism: Applied physiology

Summary Bilirubin is the breakdown product of the haem moiety of haemoglobin and other haemoproteins. Because of internal hydrogen bonding, bilirubin is water-insoluble and requires enzyme-mediated glucuronidation in the liver for biliary excretion. In normal circumstances, plasma bilirubin is mostly unconjugated and is tightly bound to circulating albumin. It is taken up by hepatocytes by facilitated diffusion, stored in hepatocytes bound to glutathione-S-transferases and conjugated to glucuronides by microsomal UGT1A1. Bilirubin glucuronides are actively transported into the bile canaliculi by the ATP-utilizing pump MRP2. Bilirubin is degraded in the intestine by bacteria into urobilinogens, which are partly excreted in the urine. Increased production, reduced uptake and low glucuronidation capacity can increase plasma unconjugated bilirubin levels. In cases of inherited or acquired deficiencies of bilirubin storage or excretion, both conjugated and unconjugated bilirubin accumulate in the plasma. Conjugated bilirubin is less tightly bound to albumin and is excreted in the urine. The capacities of the various steps of bilirubin throughput are finely balanced, and the expression of the gene products mediating these steps is coordinated by nuclear receptors.
International comparison of HF and microwave electromagnetic quantities

Activities to establish international agreement on measurements of high-frequency electrical quantities have been in progress since 1957 at the initiative of the International Scientific Radio Union (URSI) and the International Committee of Weights and Measures (CIPM). Results accomplished and the overall up-to-date status are presented.
Extending Genomics to Natural Communities and Ecosystems

An important step in the integration of ecology and genomics is the progression from molecular studies of relatively simple model systems to complex field systems. The recent availability of sequenced genomes from key plants is leading to a new understanding of the molecular drivers of community composition and ecosystem processes. As genome sequences accumulate for species that form intimate associations in nature, a detailed view may emerge as to how these associations cause changes among species at the nucleotide level. This advance could dramatically alter views about the structure and evolution of communities and ecosystems.
Application of the Long-Period X-ray Standing Wave Technique to the Analysis of Surface Reactivity: Pb(II) Sorption at α-Al2O3/Aqueous Solution Interfaces in the Presence and Absence of Se(VI)

A long-period X-ray standing wave (XSW) study of the reactivity of mineral surfaces in contact with metal(loid)-bearing aqueous solutions is presented. Experimental XSW fluorescence yield data for ...
Fast atom bombardment combined with mass spectrometry for characterization of polycyclic aromatic hydrocarbons.

A new approach using fast atom bombardment combined with mass spectrometry to characterize polycyclic aromatic hydrocarbons (PAHs) in the range of 128-252 u molecular weight is described. Sulfolane was employed as a liquid matrix for these π-conjugated hydrocarbons. Bombardment of sulfolane solution of certain PAHs with an atom beam produces both radical cation (M+.) and protonated molecule [(M + H)+], with no evidence of fragmentation. Collisional activation of the fast atom bombardment-desorbed M+. ions, however, results in several structure-specific fragment ions. Structural differences in a few isomeric hydrocarbons can be detected using the [(M + H)+]/[M+.] abundance ratio and in the pyrene-fluoranthene pair by the B/E linked-field-collision-activated dissociation data. The [(M + H)+]/[M+.] was found to be compound-specific and correlated well with certain properties (resonance energy, proton affinity, and ionizing energy) of PAHs.
Distinctive information and false recognition: The contribution of encoding and retrieval factors

Four experiments evaluated the role of encoding-based and retrieval-based factors in the production of false recognition. The association of unusual fonts with study items, the match between study and test font, and the duration of retrieval time allotted to subjects to make recognition memory decisions were varied in order to examine the role encoding and retrieval play. The combined results of these experiments suggest that both encoding and retrieval are important for understanding false recognition. Additionally, the results of these studies suggest that visual features encountered at encoding can become associated with representations of unstudied items. This association, in turn, can lead to inflated levels of false recognition when unstudied items are tested in a visual format experienced at encoding or when participants utilize monitoring processes to search memory for evidence of perceptual information encountered during encoding.
Orthopedic pitfalls in the ED: Slipped capital femoral epiphysis

Slipped capital femoral epiphysis (SCFE), though a relatively common disorder, is frequently missed on initial presentation. Symptoms can be vague, the physical examination unrevealing, and radiographic abnormalities subtle. Prompt diagnosis of SCFE is important, however, to improve clinical outcome. The emergency physician needs to remain vigilant for this diagnosis to avoid this orthopedic pitfall. This article examines the clinical presentation, diagnostic techniques, and management options applicable to the emergency physician in the treatment of SCFE.
Emotional labor: A conceptualization and scale development

Abstract Despite increased research attention, the emotional labor construct remains without a clear conceptualization and operationalization. This study designed a conceptually grounded, psychometrically sound instrument to measure emotional labor with an emphasis on the experience of discrete emotions—the Discrete Emotions Emotional Labor Scale (DEELS). This conceptualization and operationalization of emotional labor departs from existing efforts because it focuses on the behavior of emotional expression, encompassing genuine, faked, and suppressed positive and negative emotional displays. Results provide initial evidence for the convergent, discriminant, and criterion-related validity of the DEELS.
New saliva DNA collection method compared to buccal cell collection techniques for epidemiological studies

Epidemiological studies may require noninvasive methods for off-site DNA collection. We compared the DNA yield and quality obtained using a whole-saliva collection device (Oragene DNA collection kit) to those from three established noninvasive methods (cytobrush, foam swab, and oral rinse). Each method was tested on 17 adult volunteers from our center, using a random crossover collection design and analyzed using repeated-measures statistics. DNA yield and quality were assessed via gel electrophoresis, spectophotometry, and polymerase chain reaction (PCR) amplification rate. The whole-saliva method provided a significantly greater DNA yield (mean +/- SD = 154.9 +/- 103.05 microg, median = 181.88) than the other methods (oral rinse = 54.74 +/- 41.72 microg, 36.56; swab = 11.44 +/- 7.39 microg, 10.72; cytobrush = 12.66 +/- 6.19, 13.22 microg) (all pairwise P < 0.05). Oral-rinse and whole-saliva samples provided the best DNA quality, whereas cytobrush and swab samples provided poorer quality DNA, as shown by lower OD(260)/OD(280) and OD(260)/OD(230) ratios. We conclude that both a 10-ml oral-rinse sample and 2-ml whole-saliva sample provide sufficient DNA quantity and better quality DNA for genetic epidemiological studies than do the commonly used buccal swab and brush techniques.
Revisiting Fisher’s ‘Lady Tasting Tea’ from a perspective of sensory discrimination testing

Abstract The Lady Tasting Tea is a famous real story in the history of development of statistics, related to R.A. Fisher, one of the greatest statisticians and founders of modern statistics. The main learning and insight offered by this paper from revisiting the story are that the methodology of conventional sensory difference tests can be and should be expanded to cover the ‘M + N’ method with larger M and N. Unlike the conventional discrimination tests, which use multiple sets of ‘M + N’ samples with small M and N based on a binomial model, the ‘M + N’ tests with larger M and N can reach a statistical significance in a single trial using only one set of ‘M + N’ samples based on a hypergeometric distribution in Fisher’s exact test. This paper explores the applications of the new methods particularly in assessing performance of trained sensory panels and panelists. The connection of the odds ratio or common odds ratio with Cohen’s standardized mean difference d is also discussed.
Why people use Yelp.com: An exploration of uses and gratifications

This study examines why individuals use the website Yelp.com from a uses and gratifications perspective. Male and female Yelp.com users who were 18 and over completed an online survey. The results of the study indicate that individuals overwhelmingly use Yelp.com for information-seeking purposes, followed by entertainment, convenience, interpersonal utility, and pass time. Further, there was an overall higher usage of each need for the readers and writers of restaurant reviews compared with readers only, suggesting more involvement for the reader and writer group. Frequency of Yelp.com usage and perceived influence of Yelp.com restaurant reviews were also positively related to the majority of motives. Theoretical and practical implications of these findings are discussed, as well as suggestions for future research.