cssi/SciSciGPT-SciSciNet huggingface dataset:
Nitroglycerin and Other Nitrites in the Treatment of Angina Pectoris Comparison of Six Preparations and Four Routes of Administration

The close chemical relationship between glyceryl trinitrate and erythrol tetranitrate suggests that these 2 drugs, despite clinical evidence to the contrary, should be equally effective in preventing attacks of angina pectoris. This proved to be true when the drugs were administered by the same route. Thus, erythrol tetranitrate when administered sublingually (instead of being swallowed, as is the custom) behaves like nitroglycerin and is one of the most effective vasodilators available. Conversely, nitroglycerin when swallowed (instead of being taken sublingually, as is the custom) is ineffective and erratic in activity. A similar striking increase in vasodilating action on sublingual administration is seen also with mannitol hexanitrate and triethanolamine trinitrate and to a lesser extent with pentaerythritol tetranitrate but not with sodium nitrite. The prolonged effect of erythrol tetranitrate, when administered sublingually or in the buccal pouch, makes it particularly valuable in the clinical manag...
Representing Tenochtitlan: Understanding Urban Life by Collecting Material Culture

How can museums best document and represent the complexity of urban life and the significance of modern cities? We consider this question through an examination of the Aztec World exhibit, presented at the Field Museum of Chicago from October 2008 through April 2009. We explain how the effort to represent Tenochtitlan, the heterogeneous urban capital of the Aztec Empire (C.E. 1428‐1521), was affected by the acquisitions policies of museums in the United States and Mexico, and by the curators’ own ideas about how urban societies should be represented. Drawing on this background, we outline how a careful and comprehensive collection program can resist poor interpretation and misrepresentation, and may even prefigure new and better understandings of cities that will be gained in the future. [urbanism, material culture, Aztec Empire, Mexico]
Optimising muscle parameters in musculoskeletal models using Monte Carlo simulation.

The use of musculoskeletal simulation software has become a useful tool for modelling joint and muscle forces during human activity, including in reduced gravity because direct experimentation is difficult. Knowledge of muscle and joint loads can better inform the design of exercise protocols and exercise countermeasure equipment. In this study, the LifeModeler™ (San Clemente, CA, USA) biomechanics simulation software was used to model a squat exercise. The initial model using default parameters yielded physiologically reasonable hip-joint forces but no activation was predicted in some large muscles such as rectus femoris, which have been shown to be active in 1-g performance of the activity. Parametric testing was conducted using Monte Carlo methods and combinatorial reduction to find a muscle parameter set that more closely matched physiologically observed activation patterns during the squat exercise. The rectus femoris was predicted to peak at 60.1% activation in the same test case compared to 19.2% a...
Cellular resistance to oxidative stress is accompanied by resistance to cisplatin: the significance of increased catalase activity and total glutathione in hydrogen peroxide-resistant fibroblasts.

Studies designed to better understand the involvement of cellular resistance to oxidative stress in mechanisms of cellular resistance to cisplatin were undertaken using H2O2-resistant variants of the HA 1 Chinese hamster fibroblast cell line. H2O2-resistant cell lines were resistant to clonogenic inactivation mediated by cisplatin with dose modifying factors at 10% survival of 1.5–3.0, relative to HA 1 cells. The most cisplatin resistant of these cell lines (OC5) also demonstrated fewer DNA–DNA crosslinks induced by cisplatin, relative to HA 1. Since H2O2-resistant cells contained increased catalase activity as well as total glutathione (GSH) content, the involvement of these cellular antioxidants in the resistance to cisplatin toxicity was evaluated. Treatment of HA 1 and H2O2-resistant cell lines (OC5, OC14) with 9 mM aminotriazole reduced catalase activity by 60–65% but had no effect on the cytotoxicity of cisplatin. In contrast, treatment with 5 mM buthionine sulfoximine reduced total GSH by 90% and sensitized the cells to cisplatin cytotoxicity. Furthermore, extracellular reaction of GSH with cisplatin prior to treating HA 1 cells reduced the toxicity of the compound, indicating that this reaction is capable of participating in the detoxification of cisplatin. These results indicate that cellular adaptation to oxidative stress renders cells resistant to DNA damage as well as to cytotoxicity associated with cisplatin treatment. Furthermore, increases in total GSH content (but not catalase activity) appear to partially account for cisplatin resistance demonstrated by H2O2-resistant cells. © 1993 Wiley-Liss, Inc.
1H NMR investigation of thermally triggered insulin release from poly(N-isopropylacrylamide) microgels.

We describe investigations of insulin release from thermoresponsive microgels using variable temperature 1H NMR. Microgel particles composed of poly(N-isopropylacrylamide) were loaded with the peptide via a swelling technique, and this method was compared to simple equilibrium partitioning. Variable temperature 1H NMR studies suggest that the swelling loading method results in enhanced entrapment of the peptide versus equilibrium partitioning. A centrifugation-loading assay supports this finding. Pseudo-temperature jump 1H NMR measurements suggest that the insulin release rate is partially decoupled from microgel collapse. These types of direct release investigations could prove to be useful methods in the future design of controlled macromolecule drug delivery devices.
Associative Hebbian Synaptic Plasticity in Primate Visual Cortex

In primates, the functional connectivity of adult primary visual cortex is susceptible to be modified by sensory training during perceptual learning. It is widely held that this type of neural plasticity might involve mechanisms like long-term potentiation (LTP) and long-term depression (LTD). NMDAR-dependent forms of LTP and LTD are particularly attractive because in rodents they can be induced in a Hebbian manner by near coincidental presynaptic and postsynaptic firing, in a paradigm termed spike timing-dependent plasticity (STDP). These fundamental properties of LTP and LTD, Hebbian induction and NMDAR dependence, have not been examined in primate cortex. Here we demonstrate these properties in the primary visual cortex of the rhesus macaque (Macaca mulatta), and also show that, like in rodents, STDP is gated by neuromodulators. These findings indicate that the cellular principles governing cortical plasticity are conserved across mammalian species, further validating the use of rodents as a model system.
Novel NMR tools to study structure and dynamics of biomembranes.

Nuclear magnetic resonance (NMR) studies on biomembranes have benefited greatly from introduction of magic angle spinning (MAS) NMR techniques. Improvements in MAS probe technology, combined with the higher magnetic field strength of modern instruments, enables almost liquid-like resolution of lipid resonances. The cross-relaxation rates measured by nuclear Overhauser enhancement spectroscopy (NOESY) provide new insights into conformation and dynamics of lipids with atomic-scale resolution. The data reflect the tremendous motional disorder in the lipid matrix. Transfer of magnetization by spin diffusion along the proton network of lipids is of secondary relevance, even at a long NOESY mixing time of 300 ms. MAS experiments with re-coupling of anisotropic interactions, like the 13C–1H dipolar couplings, benefit from the excellent resolution of 13C shifts that enables assignment of the couplings to specific carbon atoms. The traditional 2H NMR experiments on deuterated lipids have higher sensitivity when conducted on oriented samples at higher magnetic field strength. A very large number of NMR parameters from lipid bilayers is now accessible, providing information about conformation and dynamics for every lipid segment. The NMR methods have the sensitivity and resolution to study lipid–protein interaction, lateral lipid organization, and the location of solvents and drugs in the lipid matrix.
The effect of para-cholorophenylalamine and scopolamine on passive avoidance in chicks☆

Abstract Four-day-old Vantress x Arbor Acre chicks were tested for key-peck passive avoidance (PA) learning following intraperitoneal injections of parachlorophenylalanine (PCPA) and/or scopolamine. In Experiment 1, chicks were pre-treated with either three or five injections of PCPA (150 mg/kg) or saline across the first three posthatch days and then tested for PA learning on the fourth posthatch day. In Experiment 2, chicks were first pre-treated with three injections of PCPA (150 mg/kg) or saline, and then injected with either scopolamine (0.5 mg/kg) or saline 20 min prior to PA testing on the fourth posthatch day. Major findings were: (a) Chicks pre-treated with PCPA did not significantly differ from saline control chicks in either the acquisition or maintenance of response suppression during PA testing; (b) chicks injected with scopolamine were significantly disrupted in PA learning as compared to saline control chicks; and (c) PCPA pre-treatment did not significantly affect the scopolamine-induced disruption of PA learning. These findings, therefore, suggest that cholinergic, but not serotonergic, mechanisms are involved in PA learning of the young chick.
Evaluation of alternative approaches for screening contaminated sediments and soils for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans.

Traditional high resolution mass spectrometry (HRMS) analysis for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) can be time consuming and expensive. Consequently, alternative methods are of great interest to regulatory agencies and others characterizing contaminated sites. One factor that hinders acceptance of alternative methods is a lack of performance information that assesses the alternative method's impacts on analytical results. The U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation Monitoring and Measurement Technologies Program (EPA SITE MMT) encourages the development and implementation of innovative and alternative monitoring methods by providing performance information on site characterization technologies. This paper presents a comparison of the results obtained from laboratory-based alternative approaches for screening sediment and soil samples for dioxin toxicity equivalents (TEQD/F) to results obtained using traditional HRMS. The laboratory-based approaches included modifying the traditional HRMS analysis to make it more cost-effective (alternate 1613B), analyzing extracts that had been prepared for HRMS using low resolution mass spectrometry, and determining total organic carbon (TOC) content as an indicator of PCDD/F content. These comparisons demonstrated that TEQD/F values generated using toxicity equivalency factors proposed by the World Health Organization in 1998 applied to alternate 1613B and LRMS analyses have a strong linear correlation to the TEQD/F values derived in the same fashion from traditional HRMS analysis. These results would have placed >90% of the samples within the same concentration intervals using ranges of 5 ng TEQ/g. Natural log transformed data for TOC had significantly weaker correlation to TEQD/F, indicating that TOC is not a reliable indicator of TEQD/F concentrations.
Simultaneous Confidence Intervals for Variances

Abstract Given a sample of n vector observations from a multivariate normal population, Anderson and Roy-Gnanadesikan have given for the variances a set of confidence intervals which are approximate in that a lower bound only is known for the joint confidence coefficient. In the present study, exact procedures are developed in terms of multivariate Chi-Square distributions, and more general approximate procedures are given via Bonferroni's inequality. A numerical investigation suggests that the Bonferroni lower bound is fairly sharp for a variety of parameter values, and it always is superior to the Roy-Gnanadesikan procedure in the bivariate case examined. A lower bound in terms of independent statistics further is examined for a special class of one-sided intervals.
Optical down-conversion in doped ZnSe:Tb3+ nanocrystals

Rare earth (RE) Tb(3+)-doped high quality ZnSe nanocrystals (NCs) were synthesized by a facile chemical hot-injection method. ZnSe:Tb(3+) nanocrystals exhibited broadband absorption below the first excitonic absorption peak. Photoluminescence spectra showed Tb(3+) emission lines in the visible spectral window at room temperature when excited by UV radiation below the band-edge of the host ZnSe nanocrystals. Our experimental results indicate optical down-conversion in these Tb(3+)-doped Zn-chalcogenide nanocrystals via energy migration from host ZnSe to the Tb(3+) dopant. The host-dopant energy transfer mechanism for this ZnSe:Tb(3+) nanocrystal system is correlated with the emission spectra.
Icosahedral clusters with pair interaction of atoms

Abstract Expressions for the total binding energy of atoms in icosahedral clusters with unfilled layers are obtained for a short-range interactions of atoms. These results and numerical calculations for the Lennard_Jones clusters with filled layers allow one to find the binding energy for the Lennard-Jones clusters with unfilled layers. Comparison of energetic parameters for clusters with icosahedral and face-centered cubic structures shows that the competition between these structures of clusters takes place in a wide range of cluster sizes.
Dopamine covalently modifies and functionally inactivates parkin

Inherited mutations in PARK2, the gene encoding parkin, cause selective degeneration of catecholaminergic neurons in the substantia nigra and locus coeruleus of the brainstem, resulting in early-onset parkinsonism. But the role of parkin in common, sporadic forms of Parkinson disease remains unclear. Here we report that the neurotransmitter dopamine covalently modifies parkin in living dopaminergic cells, a process that increases parkin insolubility and inactivates its E3 ubiquitin ligase function. In the brains of individuals with sporadic Parkinson disease, we observed decreases in parkin solubility consistent with its functional inactivation. Using a new biochemical method, we detected catechol-modified parkin in the substantia nigra but not other regions of normal human brain. These findings show a vulnerability of parkin to modification by dopamine, the principal transmitter lost in Parkinson disease, suggesting a mechanism for the progressive loss of parkin function in dopaminergic neurons during aging and sporadic Parkinson disease.
Forensic discovery auditing of digital evidence containers

Current digital forensics methods capture, preserve, and analyze digital evidence in general-purpose electronic containers (typically, plain files) with no dedicated support to help establish that the evidence has been properly handled. Auditing of a digital investigation, from identification and seizure of evidence through duplication and investigation is, essentially, ad hoc, recorded in separate log files or in an investigator's case notebook. Auditing performed in this fashion is bound to be incomplete, because different tools provide widely disparate amounts of auditing information - including none at all - and there is ample room for human error. The latter is a particularly pressing concern given the fast growth of the size of forensic targets. Recently, there has been a serious community effort to develop an open standard for specialized digital evidence containers (DECs). A DEC differs from a general purpose container in that, in addition to the actual evidence, it bundles arbitrary metadata associated with it, such as logs and notes, and provides the basic means to detect evidence-tampering through digital signatures. Current approaches consist of defining a container format and providing a specialized library that can be used to manipulate it. While a big step in the right direction, this approach has some non-trivial shortcomings - it requires the retooling of existing forensic software and, thereby, limits the number of tools available to the investigator. More importantly, however, it does not provide a complete solution since it only records snapshots of the state of the DEC without being able to provide a trusted log of all data operations actually performed on the evidence. Without a trusted log the question of whether a tool worked exactly as advertised cannot be answered with certainty, which opens the door to challenges (both legitimate and frivolous) of the results. In this paper, we propose a complementary mechanism, called the Forensic Discovery Auditing Module (FDAM), aimed at closing this loophole in the discovery process. FDAM can be thought of as a 'clean-room' environment for the manipulation of digital evidence, where evidence from containers is placed for controlled manipulation. It functions as an operating system component, which monitors and logs all access to the evidence and enforces policy restrictions. This allows the immediate, safe, and verifiable use of any tool deemed necessary by the examiner. In addition, the module can provide transparent support for multiple DEC formats, thereby greatly simplifying the adoption of open standards.
Crystallogenesis of bacteriophage P22 tail accessory factor gp26 at acidic and neutral pH

The crystallogenesis of bacteriophage P22 tail-fiber gp26 is described. To study possible pH-induced conformational changes in gp26 structure, native trimeric gp26 has been crystallized at acidic pH (4.6) and a chimera of gp26 fused to maltose-binding protein (MBP-gp26) has been crystallized at neutral and alkaline pH (7-10). Gp26 is one of three phage P22-encoded tail accessory factors essential for stabilization of viral DNA within the mature capsid. In solution, gp26 exists as an extended triple-stranded coiled-coil protein which shares profound structural similarities with class I viral membrane-fusion protein. In the cryo-EM reconstruction of P22 tail extracted from mature virions, gp26 forms an ∼220 A extended needle structure emanating from the neck of the tail, which is likely to be brought into contact with the cell’s outer membrane when the viral DNA-injection process is initiated. To shed light on the potential role of gp26 in cell-wall penetration and DNA injection, gp26 has been crystallized at acidic, neutral and alkaline pH. Crystals of native gp26 grown at pH 4.6 diffract X-rays to 2.0 A resolution and belong to space group P2{sub 1}, with a dimer of trimeric gp26 molecules in the asymmetric unit. To study potential pH-induced conformational changes in the gp26more » structure, a chimera of gp26 fused to maltose-binding protein (MBP-gp26) was generated. Hexagonal crystals of MBP-gp26 were obtained at neutral and alkaline pH using the high-throughput crystallization robot at the Hauptman–Woodward Medical Research Institute, Buffalo, NY, USA. These crystals diffract X-rays to beyond 2.0 A resolution. Structural analysis of gp26 crystallized at acidic, neutral and alkaline pH is in progress.« less
Age-related changes in the latency of the visual evoked potential: Influences of check size ☆

Abstract Pattern reversal visual evoked potentials were recorded from 125 visually normal adults between 10 and 80 years of age. Two check sizes, 12 and 48 min, were used. The results showed that the latency of the first major positive component, P 1 , increased with age for both check sizes. This rate of increase was nearly twice as fast for 12 min checks. This difference is most likely a reflection of the differential effects of aging processes on the various spatial frequency channels in the human visual system.
Linearly elastic annular and circular membranes under radial, transverse, and torsional loading. Part I: large unwrinkled axisymmetric deformations

Three theories for determination of the equilibrium states of initially flat, linearly elastic, rotationally symmetric, taut membranes are considered: Foppl-von Karman theory, Reissner’s theory, and a new generalization of Reissner’s theory that does not restrict the strains to be small. Attention is focused on annular membranes, but circular membranes are also treated. Large deformations are allowed, and the equilibrium equations are written in terms of transverse, radial, and circumferential displacements. Problems considered include radial stretching, transverse displacement of the inner edge, an adhesive punch pull-off test on a circular blister, transverse pressure, ponding of annular and circular membranes, a vertical distributed load with a vertically sliding outer membrane edge, pull-in (snap-down, jump-to-contact) instability of a MEMS device, torsion of the inner or outer edge of a stretched membrane, and a combination of radial stretching, vertical displacement, and torsion. Results for the three theories are compared. Closed-form solutions are available in a few cases, but usually a shooting method is utilized to obtain numerical solutions for displacements, strains, and stresses. Conditions for the onset of wrinkling are determined. In the second part of this two-part study, small vibrations about equilibrium configurations are analyzed.
Dynamics of Weather Regimes: Quasi-Stationary Waves and Blocking.

Abstract We hypothesize that periods of quasi-stationary behavior in the large scales are integrally associated with an organized behavior of the synoptic scales, thus the terminology “weather regime.” To investigate our hypothesis, we extend the model of Charney and Straus (1980) to include an additional wave in the zonal direction which is highly baroclinically unstable and can interact directly with the externally forced large-scale wave. We find that such a model aperiodically vacillates between two distinct weather regime states which are not located near any of the stationary equilibria of the large-scale state; thus, we cannot ascertain the qualitative behavior of the large-scale flow in our model knowing only the large-scale equilibria and their respective stabilities to perturbations on the scale of the equilibria. The state of the model flow may remain in either one of the two regime states for several synoptic periods. During each of the two regimes, the net transports by the transient disturba...
Acidification, bleaching and oxygen consumption with chlorophyll-containing lipid microvesicles

When chlorophyll-lipid microvesicles under aerobic conditions were illuminated with intense white light; (a) the media became more acidic, (b) the lipid microvesicles bleached from green to yellow and (c) oxygen was taken up from the bathing solution. The bleaching, which was followed spectrophotometrically, resulted in a decrease in the total chlorophyll content as well as the chlorophyll a : b ratio. Some bleaching, which was slowed by the presence of electron donors, occurred in the dark. Water-soluble electron donors were shown to increase the rate of oxygen consumption with the order of effectiveness being; control = KI = ferrocyanide < hydroquinone < thiourea < cysteine < NADH < Fe+2 < ascorbic acid < phenylhydrazine. Chlorophyll mediated electron transfer from donors to oxygen is similar to that of the well known Krasnovsky reactions (in organic solvents and aqueous detergent suspensions) and Mehler reaction (in chloroplast suspension). Electron acceptors and β-carotene had no effect on the oxygen consumption. Lipid-soluble quinones and α-tocopherol affected the oxygen reaction to different extents. The reactions reported here are closely related to those previously described for chlorophyll in organic solvents, “quantasomes” and chloroplasts. The demonstration of these reactions in chlorophyll-lipid microvesicles is an advance in making the chlorophyll-lipid microvesicles a better model of the thylakoid membrane.
Reference beyond the walls of the library: Interacting with faculty and students in the 21st century

SUMMARY The nature of research continues to evolve from accessing print publications in a library building toward retrieving information online, any time any place. Since patrons no longer need to enter a library building to access information, the social character of reference service has also changed. Demand for face-to-face reference interaction has declined, altering the traditional one-on-one venue for teaching information retrieval and evaluation. To develop new opportunities for influencing the information literacy levels of students, librarians at Northwest Missouri State University are creating outreach strategies that facilitate increased interaction with students and faculty.
Dietary supplementation with monosodium glutamate is safe and improves growth performance in postweaning pigs.

Dietary intake of glutamate by postweaning pigs is markedly reduced due to low feed consumption. This study was conducted to determine the safety and efficacy of dietary supplementation with monosodium glutamate (MSG) in postweaning pigs. Piglets were weaned at 21 days of age to a corn and soybean meal-based diet supplemented with 0, 0.5, 1, 2, and 4 % MSG (n = 25/group). MSG was added to the basal diet at the expense of cornstarch. At 42 days of age (21 days after weaning), blood samples (10 mL) were obtained from the jugular vein of 25 pigs/group at 1 and 4 h after feeding for hematological and clinical chemistry tests; thereafter, pigs (n = 6/group) were euthanized to obtain tissues for histopathological examinations. Feed intake was not affected by dietary supplementation with 0–2 % MSG and was 15 % lower in pigs supplemented with 4 % MSG compared with the 0 % MSG group. Compared with the control, dietary supplementation with 1, 2 and 4 % MSG dose-dependently increased plasma concentrations of glutamate, glutamine, and other amino acids (including lysine, methionine, phenylalanine and leucine), daily weight gain, and feed efficiency in postweaning pigs. At day 7 postweaning, dietary supplementation with 1–4 % MSG also increased jejunal villus height, DNA content, and antioxidative capacity. The MSG supplementation dose-dependently reduced the incidence of diarrhea during the first week after weaning. All variables in standard hematology and clinical chemistry tests, as well as gross and microscopic structures, did not differ among the five groups of pigs. These results indicate that dietary supplementation with up to 4 % MSG is safe and improves growth performance in postweaning pigs.
Identifying Homogeneous Periods in Bus Route Origin-Destination Passenger Flow Patterns from Automatic Passenger Counter Data:

Bus passenger origin-destination (O-D) flow matrices portray information on travel patterns that can be used for route planning, design, and operations functions. Because travel patterns are known to vary throughout the day, O-D flow matrices can be expected to vary throughout the day as well. A method identifies time-of-day periods of homogeneous normalized bus route O-D passenger flow matrices in which a normalized matrix depicts the probabilities that a random passenger in the homogeneous period will travel from various origin stops to various destination stops on the route. The method uses bus trip automatic passenger counter data to estimate trip-level O-D matrices, aggregates the trip-level O-D matrices into elemental matrices for relatively short time periods, and then considers these elemental matrices as inputs to a traditional clustering procedure that is modified to ensure that a cluster indicating a period of homogeneous normalized O-D flow spans a continuous time period during the day. The ho...
Heterogeneous humoral and hemocyte-associated lectins with N-acylaminosugar specificities from the blue crab, Callinectes sapidus Rathbun.

Abstract 1. 1. Callinectes sapidus serum and hemocyte microsomal fraction agglutinated a panel of untreated and enzyme treated vertebrate erythrocytes and cultured lymphoid cell lines. 2. 2. Crossed absorption experiments suggested the presence of multiple specific lectins in the serum. 3. The microsomal fraction showed a 35-fold increase in specific activity when compared to the hemocyte lysate suggesting that hemocyte lectins are membrane-associated. 3. 4. Agglutination by serum and hemocyte lectins was inhibited by low concentrations of N-acylamino compounds including sialic, N-acetylmuramic and N-acetylglutamic acids, GalNAc, GlcNAc, ManNAc, and glycoproteins and polysaccharides which contain these carbohydrates: bovine submaxillary mucin, human orosomucoid, porcine stomach mucin and colominic acid. 4. 5. Hemagglutination by lectins of both serum and hemocyte microsomal fraction required divalent cations as suggested by the reduction in hemagglutination titer in the presence of the chelators EDTA, EGTA, CDTA and citrate.
Preneoplastic transformation of human mammary epithelial cells

Abstract Recent in-vitro models of mammary epithelial cell (MEC) immortalization have provided a practical approach to begin to dissect the molecular mechanisms of breast tumorigenesis. Introduction of a single oncogene, the human papilloma virus (HPV)-16 E6, induces efficient and reproducible preneoplastic transformation of normal MECs, by inducing degradation of the tumor suppressor protein p53. The role of p53 has also been demonstrated by analyses of a model of γ-radiation-induced MEC transformation. Recently, efficient retroviral gene transfer has allowed identification of multiple mammary epithelial cell types that show distinct susceptibilities to HPV E6 and E7 oncogenes, indicating a cell-type-specific predominance of the tumor suppressor proteins p53 and Rb which are targeted by E6 and E7, respectively. Further analyses of these models are likely to elucidate the biochemical mechanisms of early mammary tumorigenesis.
Salmonellae interplay with host cells

Salmonellae are important causes of enteric diseases in all vertebrates. Characterization of the molecular mechanisms that underpin the interactions of salmonellae with their animal hosts has advanced greatly over the past decade, mainly through the study of Salmonella enterica serovar Typhimurium in tissue culture and animal models of infection. Knowledge of these bacterial processes and host responses has painted a dynamic and complex picture of the interaction between salmonellae and animal cells. This Review focuses on the molecular mechanisms of these host-pathogen interactions, in terms of their context, significance and future perspectives.
Shake-Off Measurements of Electron-Ion-Scattering Phase Shifts

Continuum electrons are produced in a specific l state with high-energy resolution using shake-off photoionization. This process is well characterized, so that the photoionization signal is an accurate measurement of the difference between the continuum electron's wave-function phase and that produced by a hydrogenic interaction. Measurements are reported showing the phase of a Ba/sup +/+e/sup -/ in a d wave, in cases where it is well behaved, and in cases where doubly excited resonances produce rapid phase variations.
Effect of starch-based corn rootworm (Coleoptera : chrysomelidae) baits on selected nontarget insect species : influence of semiochemical composition

Various starch-encapsulated semiochemical-insecticide formulations, developed for potential use in adult corn root worm (Diabrotica spp.) management programs, were evaluated in the laboratory and field for effectiveness on corn root worm beetles: a carabid, Harpalus pennsylvanicus DeGeer; and a coccinellid, Coleomegilla maculata leng Timberlake. Carbaryl was formulated in pregelatinized starch matrices along with Diabroticas specific semiochemicals. The specific combination of feeding-gustatory stimulants encapsulated within or coating the outside of starch granules significantly influenced effectiveness. Allstarch formulations containing feeding-gustatory stimulants effectively killed Diabrotica virgifera virgifera LeConte adults in laboratory and field bioassays. However, H. pennsylvanicus and C. m. leng i mortality was greatly reduced when presented with starch granules coated with buffalo gourd ( Cucurbita foetidissima H.B.K.) root powder (contains cucurbitacin E, I, and E-glycoside) or purified cucurbitacin I. Cucurbitacin I and component(s) of buffalo gourd root powder appear to be C. m. lengi and H. pennsylvanicus antifeedants. In the field, significantly more C. m. lengi and D. v. virgifera were collected at traps baited with pollen-coated than root powder-coated starch granules. When granules were broadcast over plants, mortality of C. m. lengi was greater in plots receiving pollen-coated than root powder-coated granules whereas the opposite was observed for corn root worm beetles. Data suggest that to optimize the effectiveness of starch baits against D. v. virgifera and to minimize adverse effects on C. m. lengi and H. pennsylvanicus , granules coated with cucurbitacin rather than with starch or pollen should be used in corn root worm management programs.
Gene Transfer to Tumor–Infiltrating Lymphocytes and other Mammalian Somatic Cells by Microprojectile Bombardment

We demonstrate the application of particle delivery to the transformation of mammalian somatic cells. Two mouse T-lymphocyte cell lines and Chinese hamster ovary (CHO) cells were transformed transiently with the RSV-ADH (alcohol dehydrogenase) gene. Stable gene transfer was also demonstrated in CHO cells at a frequency of 6 x 10(-4) and in T-cells at a frequency of 1 x 10(-4), using beta-Gal/neomycin-resistance gene constructs. The helium gas acceleration mechanism (PDS 1000/He) and particle delivery method allowed better velocity control and particle dispersion than the gunpowder driven instrument. These improvements have increased cell viability, transformation efficiency, and cellular targets.
Abstract 3846: Vitamin D3 potentiates the antitumor effects of arsenic trioxide in human leukemia (HL-60) cells

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Arsenic trioxide (ATO) is an innovative form of therapy that has recently been found to benefit acute promyelocytic leukemia (APL) patients. Our laboratory has demonstrated that ATO stimulates oxidative stress therefore causing ATO-induced cytotoxicity in human leukemia (HL-60) cells. Pro-oxidants have been known to play a role in free radical-mediated oxidative stress. Vitamin D3, an active metabolite of vitamin D, inhibits the growth of a number of cancer types such as prostate, breast, colorectal, leukemia, and skin cancers. The specific aim of this research was to determine whether co-exposure to vitamin D3 increases the efficacy of ATO through cytotoxicity, oxidative stress and apoptosis associated with increased ATO toxicity in human leukemia (HL-60) cells. In our current investigation, we performed the MTT assay and trypan blue exclusion test to measure cell viability. We also performed the lipid peroxidation assay to determine the levels of malondialdehyde (MDA) production in HL-60 cells co-exposed to ATO and vitamin D3 in combination. The results of trypan blue exclusion and MTT assay indicated that vitamin D3 exposure potentiates the toxic activity of ATO in HL-60 cells in a dose dependent manner. Co-administration of vitamin D3 and ATO resulted in a significant (P<0.05) increase in MDA level compared to ATO alone. A statistically significant and dose-dependent increase (p <0.05) was recorded in annexin V positive cells (apoptotic cells) with increasing doses of vitamin D3 in ATO-treated cells. This finding was confirmed by the result of DNA laddering assay showing clear evidence of DNA fragmentation in ATO and vitamin D3 treated HL-60 cells. Overall, the present study indicates that vitamin D3 potentiates the antitumor effects of ATO at least part, via cytotoxicity, oxidative stress, nucleosomal fragmentation and phosphatidylserine externalization. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3846. doi:1538-7445.AM2012-3846
Ocean carbon cycle

In 1896, the Nobel Prize-winning Swedish chemist Svante Arrhenius proposed that carbon dioxide going into the atmosphere from the burning of fossil fuels such as coal, oil, and natural gas was causing a change in the transparency of the atmosphere that might result in a warming outside the realm of previous human experience. The basic greenhouse theory had been introduced almost 70 years before by the French mathematician Jean-Baptiste-Joseph Fourier, who suggested that certain gases in the atmosphere could absorb radiation, thereby trapping it much as heat is trapped in a greenhouse. By the late 1850s, British physicist John Tyndall had analyzed the radiative properties of atmospheric gases, demonstrating that carbon dioxide was among those that strongly absorb radiation emitted from the Earth. Arrhenius' idea lapsed into obscurity, in part because scientists doubted that the carbon dioxide emitted by fossil fuel burning accumulated in the atmosphere. That's because the ocean plays an unusually important ...
The Great Mimickers: Castleman Disease

Castleman disease (CD) was first described and most commonly occurs in the form of classic hyaline-vascular–type CD with hyperenhancing localized (unicentric) nonneoplastic lymphadenopathy. CD may affect any body region including unusual locations for isolated lymph node enlargement. This makes CD a great mimicker of more common benign and malignant masses in the neck, chest, abdomen, and pelvis. CD masses commonly raise the suspicion of lymphoma, paraganglioma, neuroendocrine tumor, metastatic adenopathy, solid parenchymal tumors, and infectious or inflammatory diseases. The less common plasma cell–type CD, mixed CD, and human herpes virus-8–associated CD (HHV8-CD) are more prone to lead to generalized (multicentric) adenopathy without the typical nodal hyperenhancement and are associated with B symptoms and hematologic and immunologic manifestations. The generalized forms of CD have a worse prognosis, which can approach that of malignancies. CD has multiple known associations with neoplasms, skin diseases, blood dyscrasias, and immunodeficiency, which include certain forms of lymphoma; paraneoplastic pemphigus; polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes syndrome; and plasma cell dyscrasias. Cytokine overproduction (IL-6) is an important pathogenetic factor in the development of CD. The treatment is accordingly variable, from curative or diagnostic resection of a solitary lesion to systemic chemotherapy or anti-IL-6 therapy.
Patterns of structural complexity in Alzheimer's disease and frontotemporal dementia

The goal of this project was to utilize an information theoretic formalism for medical image analysis initially proposed in [Young et al. (2005): Phys Rev Lett 94:098701-1] to detect and quantify subtle global and regional differences in spatial patterns in patients suffering from Alzheimer's disease (AD) and frontotemporal dementia (FTD) by estimating the structural complexity of anatomical brain MRI. The sensitivity and specificity of the results are compared with those of a recent analysis, currently considered state of the art for MR studies of neurodegeneration. The previous study used regional estimates of cortical thinning and/or volume loss to differentiate between normal aging, AD, and FTD. The analysis illustrates that the structural complexity estimation method, a general multivariate approach to the study of variation in brain structure which does not depend on highly specialized volumetric and thickness estimates, is capable of providing sensitive and interpretable diagnostic information.
Myocardial blood flow in awake dogs with chronic tricuspid regurgitation

The primary purpose of this study was to define regional blood flow in dogs with chronic tricuspid regurgitation (TR) in order to determine if the marked hypertrophy of the right atria resulted in compromised myocardial perfusion. Myocardial blood flow (ml/min/gm) was measured with radiolabeled microspheres in eight dogs with TR during rest, moderate exercise (5 dogs), and infusion of adenosine (1 mg/kg/min), an index of minimal vascular resistance. Similar measurements were obtained in eight normal dogs. In TR, the ratio of right atrium (RA) and right ventricle (RV) to body weight was greater than in normal dogs, 77 % and 30 %, respectively. During rest, flow in RA appendage was less than in nonappendage region in the normal dogs; no differences were noted in TR dogs, indicating an augmented hemodynamic role of the appendage in TR. Both RA and RV blood flow was greater in TR during rest but no other differences in flow were found between the two groups. Minimum vascular resistance in RV but not RA was slightly increased in TR versus normal. During marked myocyte hypertrophy, the vasculature of RA develops sufficiently to provide the same flow capacity as in the normal heart.
Who's Driving? The Role and Training of the Human Patient Simulation Operator

Within the airline industry, where much of simulation-based education originated, cockpit simulators are operated by current or former pilots whose expertise ensures the authenticity of the training experience. As yet, identifying the most appropriate person to run a patient simulator has not been translated into healthcare. Furthermore, few training resources exist for those who must learn the intricacies of the relationship between patient simulators, simulation scenarios, and educational objectives. This article reviews literature related to the role, educational preparation, and training of the patient simulator operator and explores solutions to the uncertainty about the difference between simulator operators and technicians. Because simulators are operationally intensive and because scarce faculty may be best used to facilitate student learning within the laboratory, the tendency has been to use a variety of personnel to manage patient simulators. Recommendations for standardizing the role of the operator that are consistent with the pedagogical purposes of simulation are offered. Potential questions are posed, and methods for future work are discussed.
Major-element vapor fractionation on the lunar surface: An unusual lithic fragment from the Luna 20 fines

A 250-μm fragment in the Luna 20 fines has a very fine-grained “igneous” texture and has the composition (wt.%): SiO2, 41.1; TiO2, 0.35; Al2O3, 27.2; Cr2O3, 0.14; FeO, 4.2; MnO, 0.06; MgO, 8.5; CaO, 17.8; Na2O, 0.05; and K2O < 0.02. It contains ∼ 65% plagioclase An99–100, ∼ 15% olivine Fo90, ∼ 2% Mg-Al spinel and the remainder an unusual interstitial phase with composition SiO2, 34.8; TiO2, 1.78; Al2O3, 18.3; Cr2O3, 0.04; FeO, 14.1; MnO, 0.22; MgO, 5.0; CaO, 24.1; Na2O, 0.34; K2O < 0.02. This fragment probably represents a portion of a normal highland rock (anorthositic norite) which was heated to a very high temperature by impact, lost volatiles including SiO2, and then partially crystallized. The observed phases and their inferred crystallization sequence are consistent with experimental results in the system CaOMgOAl2O3SiO2 (Schairer and Yoder, 1969), assuming the unusual phase to be a residual glass. This type of internal fractionation, leading to silica depletion in the residuum, is different from that normally observed in lunar rocks and is attributed to slightly lower bulk SiO2 resulting from vapor fractionation due to impact (which also results in lower Na2O and other volatiles). Because differentiation of the type shown by this fragment is rare in lunar materials, we infer that such major-element vapor fractionation is uncommon on the surface of the moon. The experimental CaOMgOAl2O3SiO2 phase relations also have a bearing on the lunar model proposed by D.L. Anderson in 1973: his “refractory” original lunar composition would differentiate to produce silica deficient liquids, like the unusual phase in our fragment, rather than the normal lunar crustal rocks.
In situ observation of cement particle growth during setting

The evolution of the cement paste microstructure is a complex phenomenon, which governs the setting of concrete. During setting, cement particles tend to flocculate and agglomerate due to their surface charges, attraction forces and variety of other reasons. However, it is still unclear how these developments in cement paste microstructure influence the setting of concrete. In order to better understanding the correlation between cement paste microstructure development and corresponding concrete behavior during setting, in situ observations on cement particles behaviors are essential. In this study, in situ observations on microstructure development of fresh pastes were made on three different cement pastes by using a newly developed Quantomix WETSEM™ capsuling system in a conventional scanning electron microscope. Further, by employing image analysis techniques on the captured images, microstructure changes of these cement pastes were investigated quantitatively. During the study single and multiple particle growth, hydration rate of different cement particles, and total solids growth in association with various solid concentrations and corresponding heat of hydration were studied quantitatively and as well as qualitatively. The purpose of this quantitative study is to investigate the feasibility of using such a new technology to evaluate the factors influencing the cement paste microstructure evolutions during setting.
Science Literacy Is > Strategies

Comprehension strategies, while helpful, are not sufficient to produce student achievement at high levels. The authors examine the role of background knowledge and vocabulary in developing understanding and facilitating achievement. Through purposeful instruction in vocabulary and by building and activating background knowledge, teachers can help students absorb content.
Damage to Neurons in Culture Following Medium Change: Role of Glutamine and Extracellular Generation of Glutamate

Changing the medium of primary cell cultures of CNS origin causes severe damage that is mediated via the N-methyl-D-aspartate (NMDA)-type of glutamate receptors and dependent on the presence of glutamine in the medium. Data presented here show that glutamine has two roles in culture damage: glutamine is contaminated with a small amount of glutamate, which is responsible for initiating culture damage, and glutamine is the source of the glutamate that is produced extracellularly in damaged cultures. The NMDA receptor plays a critical role minutes after medium change when the glutamate contaminating the glutamine binds to NMDA receptors; during this time, addition of a low level (10-20 microM) of 2-amino-5-phosphonovaleric acid can block most culture damage and the appearance of extracellular glutamate. A higher level (300 microM) of 2-amino-5-phosphonovaleric acid can protect cultures when added at much later times (30-60 min). Between 3 and 6 h after medium change, the concentration of extracellular glutamate starts to rise and accumulates until the end of the culture period (20 h). Medium removed from cultures at 3 h or later after medium change and incubated alone (i.e., with no cells) also continues to generate glutamate; filtration (0.22 microns pore size) or centrifugation (18,000 g) stops the appearance of this glutamate. 6-Diazo-5-oxo-L-norleucine, an inhibitor of the mitochondrial enzyme glutaminase, blocks the generation of glutamate. Mitochondria or mitochondrial fragments are probably released from the damaged cells and then convert extracellular glutamine to glutamate, resulting in generation of a high extracellular glutamate concentration.