cssi/SciSciGPT-SciSciNet huggingface dataset:
Calcium Imaging of Cortical Neurons using Fura-2 AM

Calcium imaging is a common technique that is useful for measuring calcium signals in cultured cells. Calcium imaging techniques take advantage of calcium indicator dyes, which are BAPTA-based organic molecules that change their spectral properties in response to the binding of Ca2+ ions. Calcium indicator dyes fall into two categories, ratio-metric dyes like Fura-2 and Indo-1 and single-wavelength dyes like Fluo-4. Ratio-metric dyes change either their excitation or their emission spectra in response to calcium, allowing the concentration of intracellular calcium to be determined from the ratio of fluorescence emission or excitation at distinct wavelengths. The main advantage of using ratio-metric dyes over single wavelength probes is that the ratio signal is independent of the dye concentration, illumination intensity, and optical path length allowing the concentration of intracellular calcium to be determined independently of these artifacts. One of the most common calcium indicators is Fura-2, which has an emission peak at 505 nM and changes its excitation peak from 340 nm to 380 nm in response to calcium binding. Here we describe the use of Fura-2 to measure intracellular calcium elevations in neurons and other excitable cells.
Cannabinoids in glaucoma II: The effect of different cannabinoids on intraocular pressure of the rabbit

Thirty-two different cannabinoids were tested for their ability to reduce intraocular pressure (IOP) in the rabbit. These included many of Δ9-and Δ8 -THC derivatives and metabolites along with othe...
Saddle Point in the Minimax Converse for Channel Coding

A minimax metaconverse has recently been proposed as a simultaneous generalization of a number of classical results and a tool for the nonasymptotic analysis. In this paper, it is shown that the order of optimizing the input and output distributions can be interchanged without affecting the bound. In the course of the proof, a number of auxiliary results of separate interest are obtained. In particular, it is shown that the optimization problem is convex and can be solved in many cases by the symmetry considerations. As a consequence, it is demonstrated that in the latter cases, the (multiletter) input distribution in information-spectrum (Verdu-Han) converse bound can be taken to be a (memoryless) product of single-letter ones. A tight converse for the binary erasure channel is rederived by computing the optimal (nonproduct) output distribution. For discrete memoryless channels, a conjecture of Poor and Verdu regarding the tightness of the information spectrum bound on the error exponents is resolved in the negative. Concept of the channel symmetry group is established and relations with the definitions of symmetry by Gallager and Dobrushin are investigated.
The Use of the Lead (II) Cation as the Precipitating Agent in the Quantitative Determination of Phosphorus in Organo-Phosphorus Compounds – A Study of the Lead Phosphate – Lead EDTA System

Abstract A simple procedure for the quantitative determination of Phosphorus in organic compounds through the precipitation of lead phosphate and the subsequent titration of excess lead with ethylenediaminetetraacetic acid (EDTA) was studied. The results of this study directed our investigation to the lead phosphate-lead EDTA system with a specific lead ion electrode.
Herd factors associated with dairy cow mortality.

Summary studies of dairy cow removal indicate increasing levels of mortality over the past several decades. This poses a serious problem for the US dairy industry. The objective of this project was to evaluate associations between facilities, herd management practices, disease occurrence and death rates on US dairy operations through an analysis of the National Animal Health Monitoring System’s Dairy 2007 survey. The survey included farms in 17 states that represented 79.5% of US dairy operations and 82.5% of the US dairy cow population. During the first phase of the study operations were randomly selected from a sampling list maintained by the National Agricultural Statistics Service. Only farms that participated in phase I and had 30 or more dairy cows were eligible to participate in phase II. In total, 459 farms had complete data for all selected variables and were included in this analysis. Univariable associations between dairy cow mortality and 162 a priori identified operation-level management practices or characteristics were evaluated. Sixty of the 162 management factors explored in the univariate analysis met initial screening criteria and were further evaluated in a multivariable model exploring more complex relationships. The final weighted, negative binomial regression model included six variables. Based on the incidence rate ratio, this model predicted 32.0% less mortality for operations that vaccinated heifers for at least one of the following: bovine viral diarrhea, infectious bovine rhinotracheitis, parainfluenza 3, bovine respiratory syncytial virus, Haemophilus somnus, leptospirosis, Salmonella, Escherichia coli or clostridia. The final multivariable model also predicted a 27.0% increase in mortality for operations from which a bulk tank milk sample tested ELISA positive for bovine leukosis virus. Additionally, an 18.0% higher mortality was predicted for operations that used necropsies to determine the cause of death for some proportion of dead dairy cows. The final model also predicted that increased proportions of dairy cows with clinical mastitis and infertility problems were associated with increased mortality. Finally, an increase in mortality was predicted to be associated with an increase in the proportion of lame or injured permanently removed dairy cows. In general terms, this model identified that mortality was associated with reproductive problems, non-infectious postpartum disease, infectious disease and infectious disease prevention, and information derived from postmortem evaluations. Ultimately, addressing excessive mortality levels requires a concerted effort that recognizes and appropriately manages the numerous and diverse underlying risks.
Large area thin film silicon modules with 10% efficiency for production

A stabilized total-area efficiency above 10% (ISC = 1.46 A, VOC = 148 V, FF = 67%, Pmpp = 145W, total area of 1.43m2) has been achieved on Gen 5 modules for the first time with an amorphous/microcrystalline silicon solar cell. The efficiency was enhanced by improving the light management and reducing the light induced degradation. The short circuit current density Jsc was enhanced by the introduction of internal light trapping using textured ZnO as the front transparent conductor, the implementation of an innovative µc-SiOx based p-layer and by an optical filter between the top and bottom cells of the tandem junction. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
On the theory of sexual reproductive kinetics with comments on some recent experimental results

A general formalism is presented which integrates behavioral patterns into population dynamics. These behavioral patterns can be represented by a set of linear or nonlinear state equations which are said to generate the behavioral microdynamics. It is shown that under certain time-scaling assumptions a behavioral equilibrium distribution may exist which allows a considerable simplification in the representation of the behavioral microdynamic (BMD) state space. An important BMD process, sexual reproductive kinetics, is investigated in detail with reference to the specific behavioral patterns of Drosophila melanogaster. Three subsystem sexual reproductive kinetic models are investigated: (1) male mate searching behavior, (2) female spacing behavior, and (3) the response of males to female pheromone emission. The qualitative agreement between experimental results and both the general and specific aspects of Drosophila melanogaster behavioral microdynamics is discussed.
Bounding the variance in Monte Carlo experiments

This paper describes a method for obtaining a worst-case bound on variance in a Monte Carlo experiment by using available lower and upper bounds on outcomes within disjoint strata in the corresponding sample space. This worst-case bound can be used to determine a worst-case sample size to meet a specified variance criterion.
Land-Use Intensity Effects on Soil Organic Carbon Accumulation Rates and Mechanisms

Restoring soil C pools by reducing land use intensity is a potentially high impact, rapidly deployable strategy for partially offsetting atmospheric CO2 increases. However, rates of C accumulation and underlying mechanisms have rarely been determined for a range of managed and successional ecosystems on the same soil type. We determined soil organic matter (SOM) fractions with the highest potential for sequestering C in ten ecosystems on the same soil series using both density- and incubation-based fractionation methods. Ecosystems included four annual row-crop systems (conventional, low input, organic and no-till), two perennial cropping systems (alfalfa and poplar), and four native ecosystems (early successional, midsuccessional historically tilled, midsuccessional never-tilled, and late successional forest). Enhanced C storage to 5 cm relative to conventional agriculture ranged from 8.9 g C m−2 y−1 in low input row crops to 31.6 g C m−2 y−1 in the early successional ecosystem. Carbon sequestration across all ecosystems occurred in aggregate-associated pools larger than 53 μm. The density-based fractionation scheme identified heavy-fraction C pools (SOM > 1.6 g cm−3 plus SOM 250 μm), as having the highest potential C accumulation rates, ranging from 8.79 g C m−2 y−1 in low input row crops to 29.22 g C m−2 y−1 in the alfalfa ecosystem. Intra-aggregate light fraction pools accumulated C at slower rates, but generally faster than in inter-aggregate LF pools. Incubation-based methods that fractionated soil into active, slow and passive pools showed that C accumulated primarily in slow and resistant pools. However, crushing aggregates in a manner that simulates tillage resulted in a substantial transfer of C from slow pools with field mean residence times of decades to active pools with mean residence times of only weeks. Our results demonstrate that soil C accumulates almost entirely in soil aggregates, mostly in macroaggregates, following reductions in land use intensity. The potentially rapid destruction of macroaggregates following tillage, however, raises concerns about the long-term persistence of these C pools.
Structure and infrastructure of infectious agent research literature: SARS

Text mining was used to extract technical intelligence from the open source global SARS research literature. A SARS-focused query was applied to the Science Citation Index (SCI) (SCI 2008) database for the period 1998---early 2008. The SARS research literature infrastructure (prolific authors, key journals/institutions/countries, most cited authors/journals/documents) was obtained using bibliometrics, and the SARS research literature technical structure (hierarchical taxonomy) was obtained using computational linguistics/document clustering.
Superfaces: polyhedral approximation with bounded error

We describe superfaces, a new method for simplifying closed polyhedra. The superfaces algorithm performs the simplification based on a bounded approximation criterion that produces a simplified polyhedron that approximates the original one to within a prespecified tolerance. The vertices in the simplified polyhedron are a proper subset of the original vertices, so the algorithm is well-suited for creating hierarchical representations of polyhedra.
Deeply Diverged Alleles in the Arabidopsis AREB1 Transcription Factor Drive Genome-Wide Differences in Transcriptional Response to the Environment

Gene regulatory variation is an important driver of the evolution of physiological and developmental responses to the environment. The abscisic acid (ABA) signaling pathway has long been studied as a key component of the cellular response to abiotic stresses in plants. We identify two haplotypes in an Arabidopsis thaliana transcription factor, AREB1, which plays a central role in ABA-mediated response to osmotic stress. These two haplotypes show the sequence signature of long-term maintenance of genetic diversity, suggesting a role for a diversifying selection process such as balancing selection. We find that the two haplotypes, distinguished by a large number of single nucleotide polymorphisms and the presence or absence of four small insertion/deletions in AREB1 intron 1 and exon 2, are at roughly equal frequencies in Arabidopsis, and show high linkage disequilibrium and deep sequence divergence. We use a transgenic approach, along with mRNA Sequencing-based assay of genome-wide expression levels, and find considerable functional divergence between alleles representing the two haplotype groups. Specifically, we find that, under benign soil‐water conditions, transgenic lines containing different AREB1 alleles differ in the expression of a large number of genes associated with pathogen response. There are relatively modest gene expression differences between the two transgenic lines under restricted soil water content. Our finding of pathogen-related activity expands the known roles of AREB1 in A. thaliana and reveals the molecular basis of gene-by-environment interaction in a putatively adaptive plant regulatory protein.
Metabolism and vascular fatty acid transport.

The transport of lipids into tissues with an elevated rate of cellular metabolism (e.g., skeletal muscle, heart and brown adipose tissue) partly depends on vascular endothelial growth factor B.
High pressure synthesis of thorium sesquicarbide: A new actinide carbide

Abstract Thorium sesquicarbide, having the body-centered cubic Pu 2 C 3 -type structure, has been synthesized by high pressure-high temperature techniques. A minimal pressure and temperature of approximately 30 kb and 1200 °C are required to produce the compound in high yield. Lattice parameter measurements suggest a narrow range of homogeneity. High temperature-ambient pressure annealing results in the destruction of the body-centered cubic structure. The Vegard relationship in the body-centered cubic high pressure-high temperature yttrium-thorium sesquicarbide system is illustrated.
The Reaction of μ-dithiobis(tricarbonyliron) with dimanganese decacarbonyl: a novel product and an interesting structural problem

Abstract The photo-induced reaction of (μ-S2)Fe2(CO)6 and Mn2(CO)10 in tetrahydrofuran solution gave a complex of composition S2Fe2Mn2(CO)14. A combination of X-ray crystallography, Mossbauer spectroscopy, mass spectroscopy and elemental analysis established this composition and the structure as Fe2Mn(CO)9(μ3-S)(μ4-S)Mn(CO)5, the Fe2Mn system of which contains one FeFe and one FeMn bond.
An Antisense Transcript Induced by Wnt/β-Catenin Signaling Decreases E2F4

Wnt signaling induces the nuclear accumulation of beta-catenin and transcription of specific target genes via the DNA-binding proteins TCF/Lef. Although all known beta-catenin target genes encode proteins, genome-wide RNA profiling studies indicate that many transcripts do not have this capability. Transcription factor-binding sites associated with these noncoding transcripts can be identified using unbiased techniques such as serial analysis of chromatin occupancy (SACO). We used this method to identify a beta-catenin-regulated antisense RNA expressed in HCT116 colorectal carcinoma cells, a cellular model of activated beta-catenin signaling. Genomic signature tags designating putative beta-catenin-binding sites mapped to the 3'-untranslated region (3'-UTR) of the E2F4 gene. We showed that both beta-catenin and TCF4 bind to the E2F4 3'-UTR site in vivo, inducing expression of an E2F4 antisense transcript. LiCl, which mimics Wnt signaling, also induced expression of the E2F4 antisense transcript and decreased E2F4 protein levels. This effect was blocked by a cDNA expressing the E2F4 3'-UTR sense strand. The antisense-mediated decrease in E2F4 protein was reflected by reduced E2F4 association with specific target genes, including CCNA2, CDC2, PCNA, and Rad54. We propose that Wnt/beta-catenin signaling may contribute to colorectal carcinogenesis by reducing the level of the E2F4 cell cycle repressor via an antisense mechanism.
Attempt to inhibit cytotoxic alloantibody with specific anti-receptor site antiserum☆

Abstract Utilizing a 51Cr release cytotoxicity inhibition assay, putative anti-receptor site antisera (anti-A RSB) were assayed for their capacity to inhibit specific alloantibody, a result predicted by the recent work of Ramseier and Lindenman. Utilizing various isogenic strains of rats, anti-RS antisera prepared by injecting appropriate F1 hybrid animals (A × B) with either lymph node cells (A) or specific alloantiserum (A anti-B) were found to be inactive in this assay. It appears that the Ramseier-Lindenman phenomenon cannot be corroborated using a 51Cr release inhibition assay.
High temperature phase transition in NH4H2PO4

Abstract NH 4 H 2 PO 4 (ADP) has been investigated by infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis and d.c. conductivity in the temperature range of 25–180° C. Sharp reversible changes were observed in the region from 400 to 500 cm −1 of the infrared spectra in the temperature range of 138–174° C. Similar and supportive data were obtained with DSC, TGA and DC conductivity measurements. The results clearly suggest a high temperature phase transition for ADP before its melting point.
Hunter-gatherer foraging: A linear programming approach

Abstract A linear program model is developed to examine how much effort hunter-gatherers should devote to hunting vs gathering. This foraging model contains a foraging time, a digestive capacity, and a nutritional constraint which determine the optimal solution to a given human foraging goal: nutritional maximization, foraging time minimization, risk aversion, or food storage maximization. The model is compared with the most commonly used foraging models in anthropology and is shown to be more appropriate for hunter-gatherers. Using data on present day hunter-gatherers, the model's solution is shown to indicate quantitatively that these people tend to either maximize their energy or protein intake rather than minimize their time spent providing for their energy and protein needs. The model also predicts diet proportions, absolute food intake, time spent foraging, and sexual division of labor. A general version of the model is developed where the hunting and gathering cropping rates are made functions of environmental primary production. The solutions to this model agree with world patterns of hunter-gatherer diets, foraging time, and sexual division of labor. Modifications of the model to investigate risk-averse foraging and food storage are also presented, and the model is applied to determine when agriculture/pastoralism might be adopted and how hunter-gatherer body size might be selected. Although the model appears closely to predict observed hunter-gatherer foraging, the model's sensitivity and the quality of the data available make its uncritical acceptance unwarranted at this time.
IRBIT is a novel regulator of ribonucleotide reductase in higher eukaryotes

Ribonucleotide reductase (RNR) supplies the balanced pools of deoxynucleotide triphosphates (dNTPs) necessary for DNA replication and maintenance of genomic integrity. RNR is subject to allosteric regulatory mechanisms in all eukaryotes, as well as to control by small protein inhibitors Sml1p and Spd1p in budding and fission yeast, respectively. Here, we show that the metazoan protein IRBIT forms a deoxyadenosine triphosphate (dATP)–dependent complex with RNR, which stabilizes dATP in the activity site of RNR and thus inhibits the enzyme. Formation of the RNR-IRBIT complex is regulated through phosphorylation of IRBIT, and ablation of IRBIT expression in HeLa cells causes imbalanced dNTP pools and altered cell cycle progression. We demonstrate a mechanism for RNR regulation in higher eukaryotes that acts by enhancing allosteric RNR inhibition by dATP.
Effect of Exogenous Reductant on Growth and Iron Mobilization from Ferrihydrite by the Pseudomonas mendocina ymp Strain

Growth of the Pseudomonas mendocina ymp strain on insoluble ferrihydrite is enhanced by exogenous reductants with concurrent increase in soluble iron concentrations. This shows that exogenous reductants play a substantial role in the overall microbial iron bioavailability. The exogenous reductants may work together with the siderophores, Fe-scavenging agents, to facilitate ferrihydrite dissolution.
“Another Insistence of Man”: Prolegomena to the Question of the Animal in Derrida's Reading of Heidegger

In recent years Derrida has devoted a considerable number of writings to addressing “the question of the animal,” and, more often than not, this question arises in a reading of one of Heidegger's texts. In order to appreciate more fully the stakes of Derrida's posing of this question in relation to Heidegger, in this essay I offer some prefatory remarks to the question of the animal in Derrida's reading of Heidegger. The essay opens with a careful analysis of Derrida's early essay “The Ends of Man,” in which Heidegger's “Letter on ‘Humanism”’ is read in terms of the motif of man's “proper.” Taking my point of departure from this Derridean reading of Heidegger's humanism, I return to Heidegger's “Letter” in order to uncover the manner in which Heidegger distinguishes man's “proper” from what is “improper,” namely, animality. This reading reveals that, while Heidegger offers a convincing account of the limits of metaphysical humanism, this critical account nevertheless ends up uncritically reinforcing the anthropocentrism of this same tradition. My closing suggestion is that Derrida's rethinking of animality should be understood as an extended meditation on the various consequences and effects of this dogmatic anthropocentrism in Heideggerian and post-Heideggerian thought.
Ultrastructural evidence of pulmonary capillary endothelial damage from paraquat.

Because of lack of agreement concerning the toxicity of paraquat to the pulmonary microvasculature, we have undertaken an electron microscopic study of lungs of paraquat-treated rats. Rats were injected with paraquat or sterile water (controls) intraperitoneally; the animals were then killed at 24-h intervals for 10 days post-injection. In the control animals, lung ultrastructure remained normal throughout the study. In treated animals, the initial evidence of alveolar epithelial injury occurred 24 h post-paraquat. By 48 h, severe fragmentation and desquamation of membranous pneumocytes occurred, and both alveolar and interstitial edema were present. Epithelial damage was maximal 72–96 h post-paraquat. Pulmonary capillary endothelial abnormalities were less extensive that the alveolar epithelial lesions. Endothelial damage was first observed 48 h post-paraquat. In endothelial cells on the septal (thick) side of the capillaries, the number of pinocytotic vesicles was significantly increased (P<0.05) from 48 to 96 h post-paraquat. In endothelium adjacent to damaged epithelium, abnormalities included hydration, fragmentation, discontinuity, and widened intercellular junctions; these were maximal 72–96 h post-paraquat. Although other mechanisms are probably important, damaged pulmonary capillary endothelium seems to be a factor favoring paraquat-induced pulmonary edema.
Graded constraint algebras, OSP(1, 1|2) and superstring theory

Abstract Earlier, we have established that, for a constrained system with a first class bosonic constraint algebra, the standard BRST invariance generalizes to an OSP(1, 1|2) symmetry, with four nilpotent and anticommuting BRST-type operators. Here we generalize this to arbitrary constrained systems with a graded first class constraint algebra. Our approach is based on the Fradkin- Vilkovisky formalism and uses a relation between abelian and nonabelian constraint algebras. Subsidiary constraints and generalized structure constants play an important role in the construction. As an application, we construct the OSP(1, 1|2) generators for superstrings. Here the subsidiary constraints are identified with physically relevant operators used in the unitarity proof.
A molecular mechanics study of methyl vinyl ether an related compounds

Abstract Utilizing the known structures of methyl vinyl ether and a few related compounds including anisol and phenol, the MM2 force field has been extended so that structures of these compounds may be calculated. The energy differences between conformations and configurations for many related molecules have been examined, and on the whole these are well calculated in cases where they are known. Dipole moments and heats of formation were also studied.
PHYTOPLANKTON PIGMENTS IN COASTAL LAKE MICHIGAN: DISTRIBUTIONS DURING THE SPRING ISOTHERMAL PERIOD AND RELATION WITH EPISODIC SEDIMENT RESUSPENSION1

Phytoplankton pigment distributions during the spring isothermal periods of 1998 and 1999 and their association with episodic sediment resuspension were characterized in coastal waters of southern Lake Michigan. Total andphylogenetic group chl a concentrations (derived using chemical taxonomy matrix factorization of diagnostic carotenoids) corresponded with assemblage and group biovolumes estimated from microscopic enumeration (P ≤ 0.001). Diatoms and cryptophytes dominated assemblages and together typically comprised greater than 85% of relative chl a. Total chl a concentrations and both fucoxanthin.ch1 a - 1 and alloxanthin.chl a - 1 ratios were similar across depths (P > 0.05), indicating uniform distributions of and photophysiological states for assemblages and diatoms and cryptophytes, respectively, throughout the mixed water column. Total chl a concentrations were not always spatially uniform from near-shore to offshore waters, with the greatest variability reflecting the influence of tributary inflows upon coastal assemblages. Sediment resuspension strongly influenced water column particle density and light climate; however, total and group chl a concentrations did not correspond with coefficients of K d and suspended particulate matter concentrations (P > 0.05). The correspondence of both light attenuation and suspended particulate matter concentration with relative diatom chl a (P ≤ 0.001) indicated an apparent association between sediment resuspension and diatoms. This, and the negative association (P ≤ 0.0001) between relative diatom and cryptophyte chl a, corresponded with the spatial dominance of diatom and cryptophyte chl a in near-shore and offshore waters, respectively. The presence of viable chl a and fucoxanthin within the surficial sediment layer, established this layer as a potential source of meroplanktonic diatoms for near-shore assemblages.
Slow Neutron Resonances in Cesium, Palladium, and Gold

The slow neutron total cross sections of Cs, Pd, and Au have been measured with a crystal spectrometer using beryllium as a monochromator. A strong resonance was found in Cs at 5.90 ev. The strength of this resonance is ${\ensuremath{\sigma}}_{0}{\ensuremath{\Gamma}}^{2}=144\ifmmode\pm\else\textpm\fi{}25$ barn ${\mathrm{ev}}^{2}$ with ${\ensuremath{\sigma}}_{0}=9500\ifmmode\pm\else\textpm\fi{}2000$ barns. Pd has a strong resonance at 34.1 ev with weaker ones at 26 and 13.3 ev. The 4.91-ev resonance in Au has been found to have unusual shape. If it is a single resonance, the maximum total cross section is ${\ensuremath{\sigma}}_{0}=31000\ifmmode\pm\else\textpm\fi{}1000$ barns and the total width is $\ensuremath{\Gamma}=0.175\ifmmode\pm\else\textpm\fi{}0.01$ ev.
Trasplante pulmonar pediátrico

Se han efectuado aproximadamente 700 trasplantes en ninos menores de 18 anos de edad en todo el mundo; en cambio, se han efectuado mas de 11.000 en adultos. El principal grupo diagnostico es el de fibrosis quistica. Un grupo emergente de pacientes esta constituido por los ninos que nacen con enfermedades pulmonares de base congenita, como la deficiencia de la proteina B del surfactante. La supervivencia de los ninos es muy similar a la observada en adultos, aunque, por lo general, los ninos pertenecen a una clase de riesgo mas elevado. Por ejemplo, no hay ninos que hayan sido sometidos a trasplante por enfermedad pulmonar obstructiva cronica (un grupo diagnostico de bajo riesgo), en tanto que dicho diagnostico comprende alrededor del 40 % de todos los adultos sometidosa trasplante de pulmon. La inmunosupresion consiste por lo general en ciclosporina, azatioprina y prednisona. Las complicaciones postrasplante son similares a las observadas en adultos. Alrededor del 40 % de los pacientes desarrollan una bronquiolitis obliterante hacia los 3 anos postrasplante y ello sigue constituyendo el principal impedimento para la supervivencia largo plazo. La escasez de donantes tambien es un obstaculo significativo, sobre todo en el grupo de pacientes adolescentes. Como solucion parcial a dicho problema, el trasplante pulmonar de donante vivo ha asumido mayor trascendencia en el programa. Aunque es una estrategia terapeutica compleja y costosa, el trasplante pulmonar sigue siendo el tratamiento mas eficaz de las neumopatias parenquimatosas y vasculares en estadios terminales, incluso en los ninos de menor edad.
Blocking the K-pathway still allows rapid one-electron reduction of the binuclear center during the anaerobic reduction of the aa3-type cytochrome c oxidase from Rhodobacter sphaeroides.

The K-pathway is one of the two proton-input channels required for function of cytochrome c oxidase. In the Rhodobacter sphaeroides cytochrome c oxidase, the K-channel starts at Glu101 in subunit II, which is at the surface of the protein exposed to the cytoplasm, and runs to Tyr288 at the heme a3/CuB active site. Mutations of conserved, polar residues within the K-channel block or inhibit steady state oxidase activity. A large body of research has demonstrated that the K-channel is required to fully reduce the heme/Cu binuclear center, prior to the reaction with O2, presumably by providing protons to stabilize the reduced metals (ferrous heme a3 and cuprous CuB). However, there are conflicting reports which raise questions about whether blocking the K-channel blocks both electrons or only one electron from reaching the heme/Cu center. In the current work, the rate and extent of the anaerobic reduction of the heme/Cu center were monitored by optical and EPR spectroscopies, comparing the wild type and mutants that block the K-channel. The new data show that when the K-channel is blocked, one electron will still readily enter the binuclear center. The one-electron reduction of the resting oxidized (“O”) heme/Cu center of the K362M mutant, results in a partially reduced binuclear center in which the electron is distributed about evenly between heme a3 and CuB in the R. sphaeroides oxidase. Complete reduction of the heme/Cu center requires the uptake of two protons which must be delivered through the K-channel.
Evaluation of the alkaline elution/rat hepatocyte assay as a predictor of carcinogenic/mutagenic potential

We have recently developed an alkaline elution/rat hepatocyte assay to sensitively measure DNA single-strand breaks induced by xenobiotics in non-radiolabeled rat hepatocytes. Here we have evaluated this assay as a predictor of carcinogenic/mutagenic activity by testing 91 compounds (64 carcinogens and 27 non-carcinogens) from more than 25 diverse chemical classes. Hepatocytes were isolated from uninduced rats by collagenase perfusion, exposed to chemicals for 3 h, harvested, and analyzed for DNA single-strand breaks by alkaline elution. DNA determinations were done fluorimetrically. Cytotoxicity was estimated by glutamate-oxaloacetate transaminase release or by trypan blue dye exclusion. The assay correctly predicted the reported carcinogenic/non-carcinogenic potential of 92% of the carcinogens tested and 85% of non-carcinogens tested. The assay detected a number of compounds, including inorganics, certain pesticides, and steroids, which give false-negative results in other short-term tests. Only 2 rat liver carcinogens were incorrectly identified; the other carcinogens incorrectly identified are weakly or questionably carcinogenic (i.e., they cause tumors only in one species, after lifetime exposure, or at high doses). Some chemicals cause DNA damage only at cytotoxic concentrations; of 16 such compounds in this study, 12 are weak carcinogens suggesting a link between DNA damage caused by cytotoxicity and carcinogenesis. Our data indicate that this assay rapidly, reproducibly, sensitively, and accurately detects DNA single-strand breaks in rat hepatocytes and that the production of these breaks correlates well with carcinogenic and mutagenic activity.
Paradoxical trafficking and regulation of 5-HT2A receptors by agonists and antagonists

5-Hydroxytryptamine(2A) (serotonin(2A), 5-HT(2A)) receptors are important for many physiologic processes including platelet aggregation, smooth muscle contraction, and the modulation of mood and perception. A large number of pharmaceutical agents mediate their actions, at least in part, by modulating the number and/or activity of 5-HT(2A) receptors. Drugs with action at 5-HT(2A) receptors are used in the treatment of many disorders, including schizophrenia, depression, and anxiety disorders. This review summarizes over two decades of research on the regulation of 5-HT(2A) receptors and provides a comprehensive review of numerous in vivo studies describing the paradoxical phenomenon of 5-HT(2A) receptor down-regulation by chronic treatment with antidepressants and antipsychotics. In addition, studies reporting antagonist-induced internalization of 5-HT(2A) receptors and other G protein-coupled receptors will be highlighted as a possible mechanism to explain this paradoxical down-regulation. Finally, a review of the cellular and molecular mechanisms that may be responsible for agonist-mediated desensitization and internalization of 5-HT(2A) receptors will be presented.
pH Required to Kill Enterococcus faecalis in Vitro

Enterococcus faecalis tolerates highly alkaline environments, yet the exact pH required for killing E. faecalis is not known. This study tests growth at 0.5 increments from pH 9.5 to 12. Twelve culture tubes were used in each group. Positive growth was measured using turbidity, a visual scale, and a spectrophotometer. At 24 h, growth was observed in all tubes at pH 9.5 and 10. At 48 h, all pH 10.5 tubes showed growth. At 72 h, six of the pH 11 tubes showed growth. After 7 days, five of the remaining pH 11 tubes were positive. No growth occurred in any of the pH 11.5 or pH 12 tubes. Apparently, pH 10.5 to 11.0 retards growth of E. faecalis, whereas no tubes showed growth at pH 11.5 or greater.
Performance analysis challenges and framework for high-performance reconfigurable computing

Reconfigurable computing (RC) applications employing both microprocessors and FPGAs have potential for large speedup when compared with traditional (software) parallel applications. However, this potential is marred by the additional complexity of these dual-paradigm systems, making it difficult to identify performance bottlenecks and achieve desired performance. Performance analysis concepts and tools are well researched and widely available for traditional parallel applications but are lacking in RC, despite being of great importance due to the applications' increased complexity. In this paper, we explore challenges and present new techniques in automated instrumentation, runtime measurement, and visualization of RC application behavior. We also present ideas for integration with conventional performance analysis tools to create a unified tool for RC applications as well as our initial framework for FPGA instrumentation and measurement. Results from a case study are provided using a prototype of this new tool.
Supraependymal neurons overlying the periventricular region of the third ventricle of the guinea pig: A correlative scanning—transmission electron microscopic study

The frequency of occurrence, distribution and morphology of supraependymal neurons associated with the third ventricular wall of the guinea pig were investigated by correlative scanning and transmission electron microscopy. Each of the specimens was located on the ciliated ventricular wall between the inferior border of the thalamus and the non-ciliated ependyma associated with the median eminence. Prominent clusters of neuronal perikaria in association with massive process bundles were observed in 7 of the 31 specimens examined. In those specimens lacking prominent neuronal networks a more diffuse array of independent nerve fibers was sometimes seen on the ependymal surface. Neuronal perikaria exhibited numerous surface protrusions and were covered by a rich meshwork of crisscrossing, varicosed fibers. Many of these cells were associated with multiple processes of varying diameters and lengths which either coursed independently over the ventricular surface or formed fasciculated bundles. As process bundles traversed the ependymal surface, individual processes branched off and either terminated within the ventricular lumen or penetrated the subjacent ependymal lining. Fibers also made contact with adjacent supraependymal neuronal elements. Correlative transmission electron microscopic observations indicate that both the perikaria and processes of such supraependymal networks possess ultrastructural features characteristic of neurons. The morphological characteristics of the intraventricular neuronal networks suggest that they may be engaged in functional interactions with the cerebrospinal fluid, with adjacent supraependymal neuronal elements and with the subjacent neuropil.
Epidermal Growth Factor Receptor Biology in Head and Neck Cancer

Epidermal growth factor receptor (EGFR) is overexpressed in several epithelial malignancies, including head and neck squamous cell carcinoma (HNSCC), which exhibits EGFR overexpression in up to 90% of tumors. EGFR ligands such as transforming growth factor alpha are also overexpressed in HNSCC. EGFR plays a critical role in HNSCC growth, invasion, metastasis and angiogenesis. However, EGFR inhibitors as monotherapy have yielded only modest clinical outcomes. Potential mechanisms for lack of response to EGFR inhibition in HNSCC include constitutive activation of signaling pathways independent of EGFR, as well as genetic aberrations causing dysregulation of the cell cycle. EGFR-directed therapy may be optimized by identifying and selecting those HNSCC patients most likely to benefit from EGFR inhibition. Resistance to EGFR inhibition may be circumvented by combination therapy employing EGFR inhibitors together with other treatment modalities.
Charge writing in silicon?silicon dioxide for nano-assembly

Interest in using electrostatics for active nano-assembly has grown significantly over the last five years. One common electret structure for such electrostatic constructs is the silicon–silicon dioxide interface. In this paper, an experimental and mathematical analysis of the process of writing negative charge spots in Si–SiO2 is presented. It is demonstrated that controlling the spread of the charge can reduce the spot size and the drop in written potential. Simulation results of a one-dimensional charging model that assumes tunnelling of electrons through the oxide and trapping within SiO2 are presented and compared with the experimental data. The model assumes charge trapping at the Si–SiO2 interface and none at the oxide–air interface or within the oxide bulk. Conducted experiments also show that although the lateral spread of charge places a lower limit on the minimum spot size in silicon–silicon dioxide structures, the use of a hydrophobic hexamethyldisilazane layer can be effective in improving the size stability of the written electrical spots.
Activities of herpes simplex virus type 1 (HSV-1) ICP4 genes specifying nonsense peptides

Synthetic oligonucleotide linkers containing translational termination codons in all possible reading frames were inserted at various positions in the cloned gene encoding the herpes simplex virus type 1 (HSV-1) immediate-early regulatory protein, ICP4. It was determined that the amino-terminal 60 percent of the ICP4 gene was sufficient for trans-induction of a thymidine kinase promoter-CAT chimera (pTKCAT) and negative regulation of an ICP4 promoter-CAT chimera (pIE3CAT); however, it was relatively inefficient in complementing an ICP4 deletion mutant. The amino-terminal ninety amino acids do not appear to be required for infectivity as reflected by the replication competence of a mutant virus containing a linker insertion at amino acid 12. The size of the ICP4 molecule expressed from the mutant virus was consistent with translational restart at the next methionine codon corresponding to amino acid 90 of the deduced ICP4 amino acid sequence.
Simulated Performance of an Adaptive Multielement Integrated Receiver Structure in Impulse or Burst Noise

We consider the convergence and tracking properties of an adaptive multielement integrated receiver structure operating in the presence of impulsive or burst noise. The receiver structure is integrated in the sense that it incorporates both the spatial/temporal predetection processing and demodulation functions in a single entity. This integrated receiver structure has been developed in previous work to approximate maximum-likelihood (ML) reception in the presence of both intersymbol interference (ISI) and spatially distributed interference (SDI) when the latter is modeled as zero-mean Gaussian noise. The present paper is devoted to a simulation study of the convergence properties of this receiver structure when the SDI is replaced by non-Gaussian impulsive or burst noise. Results indicate that the convergence characteristics are relatively insensitive to the statistics of the SDI provided that secondorder properties are held fixed, at least for moderate deviations from Gaussian behavior. For highly impulsive SDI environments, however, the adaptive system exhibits a complete failure to converge.
Detection and partial characterization of lymphoid cell surface proteases

Abstract Cultures of viable thymocytes and lymph node cells (LNC) were found to exhibit neutral protease activity toward radiolabeled protein substrates. Proteases were not actively secreted in serum-free culture. Thymocyte surface proteases were not affected by incubation of the cells in 1 m M ethylenediaminetetraacetic acid (EDTA) or 1 m M ethylene glycol bis(aminoethyl ether) N, N' -tetraacetic acid (EGTA); however, approximately 25% of lymph node cell surface protease activity was released from the cells by EDTA. It was concluded that the majority of protease activity displayed by both cell types was tightly associated with the cell surface. The inhibitor sensitivity of the cell surface proteases detected on hamster thymocytes and LNC and rat thymocytes was very similar. Cell surface protease activity was inhibited (85%) by the serine protease inhibitors diisopropylfluorophosphate (DFP) and phenylmethylsulfonylfluoride (PMSF) and was partially inhibited by l -1-tosylamide-2-phenylethylchloromethyl ketone(TPCK) and soybean trypsin inhibitor (SBTI), but not by N-α-p -tosyl- l -lysine-chloromethyl ketone (TLCK) or ϵ-aminocaproic acid (EACA). The bacterial protease inhibitor antipain was strongly inhibitory whereas leupeptin was less effective and elastinal did not inhibit cell surface protease activity. Thymocyte surface proteases were also inhibited (65%) by ZnCl 2 , but not be several other divalent cations. In LNC, both ZnCl 2 and NiCl 2 were inhibitory to a lesser extent (32% inhibition). At least one surface protease in both thymocytes and LNC could function as a plasminogen activator.
Oxidative Stability of Whey Protein‐stabilized Oil‐in‐water Emulsions at pH 3: Potential ω‐3 Fatty Acid Delivery Systems (Part B)

The oxidative stability of polyunsaturated lipids can be improved by incorporating them in oil droplets surrounded by positively charged whey protein isolate (WPI) membranes. This study dealt with the factors that influence the physical properties of WPI-stabilized oil-in-water emulsions at pH 3 Emulsions containing 5 to 50 wt% corn oil and 0.5 to 5.0 wt% WPI (protein-to-oil ratio of 1:10) were prepared at pH 3. The apparent viscosity of the emulsions increased appreciably at oil concentrations ≥ 35 wt%; however, the particle size was relatively indepndent of oil concentration. The influence of NaCl (0 to 250 mM) on the physical properties of 28 wt% emulsions was examined. Significant increases in mean particle size, apparent viscosity. and creaming instability occurred at ≥ 150 mM NaCl, which were attributed to flocculation induced by screening of the electrostatic repulsion between droplets. The influence of heat treatment (30 °C to 90 °C for 30 min) on 28 wt% emulsions was examined in the absence and presence of salt, respectively. At 0 mM NaCl, heating head little effect on the physical properties of the emulsions, presumably because the electrostatic repulsion between the droplets prevented droplet aggregation. At 150 mM NaCl, the mean particle diameter, apparent viscosity, and creaming instability of the emulsions increased considerably when they were heated above a critical temperature, which was 70 °C when salt was added before heating and 90 °C when salt was added after heating. These results have important implications for the design of WPI-stablized emulsions that could be used to incorporate functional lipids that are sensitive to oxidation, for example, ω-3 fatty acids.
Discovering Supersymmetric Particles in $W$ Boson Decay and $e^+ e^-$ Annihilation

The reported discovery of the W-boson may provide the opportunity either to discover the supersymmetric partners of the neutrino and the electron or to set greatly improved limits on their masses. We also discuss searching for scalar neutrinos in e+e- annihilation (off and on the 2').
Episomal Persistence of Recombinant Adenoviral Vector Genomes during the Cell Cycle In Vivo

Previously we showed that recombinant adenoviral helper-dependent (HD) vectors result in long-term transgene expression levels in vivo which slowly declined by 95% over a period of 1 year. In this study, we further establish that this was not predominantly immune mediated. To determine if cell turnover was responsible for the loss of transgene expression, we induced rapid hepatocyte cell cycling in mouse liver, by performing a surgical two-thirds partial hepatectomy. We observed a 55 and 65% reduction in transgene expression levels and a 50 and 71% loss of vector genomes for the HD vector and the first-generation adenoviral vector. In sharp contrast, in nonviral, episomal plasmid DNA-injected mice, transgene expression levels and DNA copy numbers decreased by 95 and 99%, respectively. These findings suggest that cell division alone was not the primary reason for the slow decrease in transgene expression levels and that recombinant adenoviral vectors have a more robust mechanism for maintaining persistence during cell cycling. Several potential mechanisms are proposed.