cssi/SciSciGPT-SciSciNet huggingface dataset:
Feline malignant lymphoma: environmental factors and the occurrence of this viral cancer in cats.

Environmental data collected on 221 feline malignant lymphoma cases and age-, sex- and breed-matched controls were analyzed to find evidence which could prove or disprove a hypothesis of horizontal transmission of feline leukemia virus (FeLV) between cats. The variables studied were divided into three groups: (1) association with other cats; (2) neutering and reproductive experience; and (3) diet, including predatory activities. The analyzed data did not support horizontal transmission of infectious FeLV from cat to cat and the consequential development of malignant lymphoma. Significant differences could not be found for association of case animals with other cats, either within or outside of the household. Secondly, there was no evidence of excess mature non-neutered cats, particularly males, in the case group. The courtship habits and territorial fights of entire males would dictate that excess of such animals should be present in the case group if horizontal transmission of infectious FeLV occurred. No evidence was found to support the hypothesis that diet, particularly predatory activities, may in some way affect risk. Various hypotheses concerning the pathogenesis of this disease in cats are discussed. Lymphome malin des felins: Facteurs lies a l'environnement et apparition de ce cancer viral chez les chats Les donnees sur l'environnement rassemblees a partir de 221 cas de lymphome malin des felins, et de temoins de měme ǎge, měme sexe et měme race, ont ete analysees pour la recherche d'elements qui pourraient confirmer ou refuter l'hypothese d'une transmission horizontale du virus de la teucemie feline (VLFe) entre les chats. Les variables etudiees ont ete divisees en trois groupes: 1) association avec d'autres chats; 2) experiences de reproduction ou de castration; et 3) alimentation, notamment le comportement predateur. Les donnees analysees n'ont pas prouve l'existence d'une transmission horizontale du VLFe infectieux d'un chat a un autre, ni le developpement consecutif d'un lymphome malin. Aucune difference significative n'a pu ětre mise en evidence en ce qui concerne l'association entre les animaux etudies et d'autres chats, soit dans la famille, soit en dehors. Deuxiemement, il n'y a aucune preuve d'un excedent de chats entiers adultes, notamment de mǎles, parmi les cas etudies. En raison du comportement des mǎles entiers a l'egard des femelles et leur habitude de lutter pour defendre leur territoire, ces animaux devraient ětre en excedent dans le groupe des cas etudies s'il existe une transmission horizontale du VLFe infectieux. L'auteur n'a pas non plus prouve que l'alimentation, et notamment le comportement predateur, influe en quoi que ce soit sur le risque. Il analyse diverses hypotheses concernant la pathogenese de cette maladie chez les chats.
The significance of microbial processes in hydrogeology and geochemistry

(methanogenesis). In aquifers contaminated by anthropogenic contaminants, an excess of available organic carbon often exists, and microbial metabolism is limited by the availability of electron acceptors. In addition to changes in groundwater chemistry, the solid matrix of the aquifer is affected by microbial processes. The production of carbon dioxide and organic acids can lead to increased mineral solubility, which can lead to the development of secondary porosity and permeability. Conversely, microbial production of carbonate, ferrous iron, and sulfide can result in the precipitation of secondary calcite or pyrite cements that reduce primary porosity and permeability in groundwater systems.
Evaluation of glutamate as a hippocampal neurotransmitter: glutamate uptake and release from synaptosomes.

The uptake and release of glutamic acid by synaptosomal preparations from rat hippocampus was studied. Glutamate uptake showed a low and high affinity component. High affinity glutamate uptake was highly depedent upon Na+, competitively inhibited by aspartic acid and was somewhat more active in fractions containing synaptosomes than in microsomal or nuclear fractions. Different hippocampal subfields showed similar kinetic properties for glutamate accumulation. The release of endogenous and exogenously loaded glutamate was studied and compared to GABA, a known neurotransmitter in the hippocampus. There were two types of K+-evoked release from crude synaptosomal fractions for both amino acids. One was Ca2+-dependent and the other was not. Purified synaptosomal fractions showed an enrichment of the Ca2+-depedent, K+-stimulated release over crude synaptosomal fractions, whereas Ca2+-independet, K+-stimulated efflux was markedly reduced in purified synaptosomes. Efflux from microsomes was K+-stimulated and showed no dependence on external Ca2+, even in the presence of A23187, the Ca2+ ionophore. Qualitatively, the characteristics of GABA and glutamate efflux were identical for both Ca2+-dependent and -independent release. Our results show that glutamate release originates primarily from synaptic endings, and that this release meets the characteristics of well-known stimulus secretion coupling processes seen for another transmitter in the hippocampus as well as many other transmitters in a wide variety of systems. These data strengthen our previous suggestion that glutamate may be a neurotransmitter in the rat hippocampus.
Finite element analysis of directional solidification of multicomponent alloys

A finite element model of dendritic solidification of multicomponent alloys is presented that includes solutal convection and is an extension of a previously developed model for solidification of binary alloys. The model is applied to simulation of the solidification of ternary and quaternary Ni‒based alloys. The role of solutal convection in the macrosegregation and the formation of freckles is analysed. Calculations show the effects of geometry and material properties on the convection patterns and the attendant segregation. © 1998 John Wiley & Sons, Ltd.
The “Law of Small Numbers”: An Unexpected and Incidental Replication

Summary Thirty-seven graduate students in nursing were given the problem set, used by Tversky and Kahneman in their study on the “law of small numbers,” as an extra credit part of a final examination for a statistics course. While some conservativism was noted, the major Tversky and Kahneman postulates were supported. These incidentally obtained replication data provide support for the contention that the tendency, induced by representativeness, to confidently make inferences is only slightly, if at all, determined by factors such as statistical and empirical sophistication, availability of normative criteria, knowledge about the shortcomings of human judgment, and the conditions under which inferences are to be made.
A Theory of Post-Stall Transients in Axial Compression Systems: Part I—Development of Equations

An approximate theory is presented for post-stall transients in multistage axial compression systems. The theory leads to a set of three simultaneous nonlinear third-order partial differential equations for pressure rise, and average and disturbed values of flow coefficient, as functions of time and angle around the compressor. By a Galerkin procedure, angular dependence is averaged, and the equations become first order in time. These final equations are capable of describing the growth and possible decay of a rotating-stall cell during a compressor mass-flow transient. It is shown how rotating-stall-like and surgelike motions are coupled through these equations, and also how the instantaneous compressor pumping characteristic changes during the transient stall process.
Perfluorooctyl bromide concentration in plasma and tissues of beagle dogs

Plasma levels were determined frequently after single doses of perfluorooctyl bromide were administered to beagle dogs at doses of either 30.8 g/kg po or 3.9 g/kg intratracheally. The apparent first-order half-life during the terminal elimination phase was about 1 day after oral medication and about 7 days after intratracheal administration. Analysis of tissues revealed the highest concentrations of the compound in abdominal fat of dogs autopsied 4 weeks later.
International Orders and International Borders: Anthropological Perspectives

Subversions of International Order: Studies in the Political Anthropology of Culture, John Borneman (Albany: State University of New York Press, 1998). 341 pp., cloth (ISBN: 0-7914-3583-0), $59.50; paper (ISBN: 0-7914-3584-9), $19.95. Border Identities: Nation and State at International Frontiers, Thomas M. Wilson, Hastings Donnan, eds. (Cambridge, U.K.: Cambridge University Press, 1998). 301 pp., cloth (ISBN: 0-5215-8315-2), $59.95; paper (ISBN: 0-5215-8745-X), $23.95. Books reviewed: Subversions of International Order: Studies in the Political Anthropology of Culture , John Borneman Border Identities: Nation and State at International Frontiers , Thomas M. Wilson and Hastings Donnan, eds.
Some new asymptotic fixed point theorems.

Abstract For a continuous self mapping f of a locally convex topological vector space which is locally compact (i.e., f maps a neighborhood of each point into a relatively compact set), it is shown that a sufficient condition for the existence of a fixed point is the existence of a compact attractor K0 such that each orbit under f has a point of K0 in its closure. The proof is based upon the circle of ideas of the Lefschetz fixed point theorem.
Bioterrorism threats: learning from inappropriate responses.

Between April 1997 and June 1999, some 200 mailed or telephoned bioterrorism threats were received at a variety of locations. Usually claiming that anthrax had been released, the threats all proved to be hoaxes. In many instances, local emergency responders treated the more than 13,000 potential victims inappropriately, in particular requiring victims to strip and undergo decontamination with bleach solutions. Narratives of several incidents indicated that many victims were distressed and embarrassed by their treatment. Their experiences underscore the need for improved local response actions and the formulation of a uniform response protocol for public health agencies. Language: en
Hurwitz series as formal functions

In this paper we continue the study, begun in [7], of properties of the ring HA of Hurwitz series over a commutative ring A with identity. In particular, we show that with its “natural” topology, HA is a complete metric space, and all of the natural mappings are continuous. Further, there is a composition which satisfies the usual properties, i.e., it is continuous, associative, has a two-sided identity, is additive and multiplicative in the left (outer) factor, and, of particular interest from the point of view of differential algebra, satisfies the chain rule. We also show that HA provides formal solutions to homogeneous linear ordinary differential equations, using Picard's method of successive approximations. It is noteworthy that these results hold independently of the characteristic of the ring A.
Agonist-specific regulation of the δ-opioid receptor

Delta opioid receptor (DOR) agonists are attractive potential analgesics, since these compounds exhibit strong antinociceptive activity with relatively few side effects. In the past decade, several novel classes of delta-opioid agonists have been synthesized. Recent experimental data indicate that structurally distinct opioid agonists interact differently with the delta-opioid receptor. Consequently, individual agonist-bound DOR conformations may interact differently with intracellular proteins. In the present paper, after a brief review of the cellular processes that contribute to homologous desensitization of the DOR signaling, we shall focus on experimental data demonstrating that chemically different agonists differ in their ability to phosphorylate, internalize, and/or down-regulate the DOR. Homologous regulation of the opioid receptor signaling is thought to play an important role in the development of opioid tolerance. Therefore, agonist-specific differences in DOR regulation suggest that by further chemical modification, delta-selective opioid analgesics can be designed that exhibit a reduced propensity for analgesic tolerance.
The Day the Counterrevolutionaries Had Waited for Arrived, y en eso llegó Fidel

Since the Fidelista forces had rounded up the last of the bandidos contrarevolucionarios in the Escambray mountains in 1967, the Cuban government had not had to face any form of militant opposition. Indeed, the United States, not understanding Fidel's potency as ajudo politician, eagerly welcomed his political opposition, thus ridding the revolutionary government of its potentially worst political problem. By the time the Soviet Union collapsed and threw the Cuban economy into a tailspin, the anti-Castro forces-over a million-had found their headquarters in South Florida. Ironically, instead of influencing policy in Cuba, they became a potent force in controlling U.S. policy toward Cuba. Led by the Cuban American National Foundation, the organized exiles, although throwing up a smokescreen of nonviolent verbiage, had one aim: to provoke a U.S. invasion of Cuba that would allow the Foundation's leaders to return and
Pharmacologic profile of amlodipine

Amlodipine is a potent calcium antagonist, inhibiting Ca2+-induced contractions of depolarized rat aorta with an IC50 of 1.9 nM. Unlike nifedipine, it displayed very slow association and dissociation with the calcium channel. The ability of amlodipine to inhibit Ca2+-induced contractions was strongly dependent on the K+ concentration present before the contraction, suggesting marked voltage dependence of action. Radioligand-binding studies in cardiac membrane preparations suggested that amlodipine may interact directly with both 1,4-dihydropyridine and diltiazem-binding sites on the calcium channel. Hemodynamic studies in anesthetized and conscious dogs showed that amlodipine is a coronary and peripheral vasodilator with a slow onset and long duration of effect, even when given by intravenous injection; the reflex stimulation of cardiac output, heart rate and myocardial contractility induced by amlodipine was attenuated by propranolol, but no marked negative inotropic or dromotropic effects were observed. Amlodipine was an effective oral antihypertensive agent in rat and dog models of hypertension, and its 24-hour duration of action in hypertensive dogs correlated well with its long plasma half-life in this species. The natriuretic properties displayed by amlodipine may contribute to its use as a first-line drug for the treatment of hypertension.
Measurements of water vapor D/H ratios from Mauna Kea, Hawaii, and implications for subtropical humidity dynamics

[1] Water vapor D/H ratios were measured from samples collected on Mauna Kea, Hawaii, in July 2006, and provide new constraints on the processes that control subtropical humidity. D/H ratios ranged from -88%o at sea level to -321‰ on the summit of Mauna Kea, with sharply decreased D/H ratios above the trade inversion. A simple Rayleigh distillation model underpredicts the observed clear-sky D/H ratios by as much as 160%o at the summit. A model that accounts for large-scale condensation, fractionation, mixing, and transport of water vapor, but ignores more detailed microphysical processes, is able to reproduce the first-order characteristics of the clear-sky free troposphere relative humidity and D/H ratios. These results are consistent with remote sensing studies of subtropical D/H ratios and suggest that subtropical clear-sky water vapor isotopologues may be relatively insensitive to microphysical processes.
Differentiation between capsaicin-induced allodynia and hyperalgesia using a thermal operant assay.

Investigations of new analgesic treatments ideally are coupled with the use of compassionate methods for pain testing in animals. Recently, we described a novel operant thermal testing device that can be used to quantify orofacial pain. The objective of the current study was to differentiate thermal allodynia from hyperalgesia using this operant thermal assay. Rats were trained to complete a task whereby they had a conflict between a positive reward and tolerance for thermal nociceptive stimulation. They were subjected to cool to hot temperatures (24-45 degrees C) and evaluated under naive (untreated), capsaicin cream (0.075%), capsaicin/morphine, or morphine test conditions. The following outcome measures were evaluated: reward intake; licking contacts; facial contacts; time to complete 25, 50, and 75% of the events (licks and face contacts); facial contact duration; ratio of reward/stimulus contacts; and ratio of facial contact duration/event. Capsaicin produced an increase in mechanical sensitivity and a significant thermal allodynic effect at 42 degrees C and hyperalgesic effect at 45 degrees C. These effects were blocked with morphine pre-treatment. The temporal profile for completing the task was also significantly altered following capsaicin treatment. These data demonstrate that using the operant orofacial assay in conjunction with capsaicin cream can provide a reproducible, sensitive, minimally invasive, and powerful approach for quantifying and studying enhanced thermal pain within the trigeminal system. This technique provides an alternative to reflex tests of orofacial sensitivity, and it presents a pivotal link for translating basic pain research into clinic trial strategies.
Role of Human Cytochromes P450 in the Metabolic Activation of Chemical Carcinogens and Toxins

(1994). Role of Human Cytochromes P450 in the Metabolic Activation of Chemical Carcinogens and Toxins. Drug Metabolism Reviews: Vol. 26, No. 1-2, pp. 165-183.
Computer model studies of the magnetocardiogram

Digital computer models of cardiac excitation and the torso were used to investigate several aspects of the magnetocardiogram (MCG). Cardiac excitation was simulated by 20 current dipoles whose locations and moments are based on experimental data reported by others. Both a homogeneous torso and an inhomogeneous torso containing lung regions with a conductivity of one-half that of the rest of the torso were used. MCG's produced by components of the magnetic field normal to the skin were calculated at 15 sites on a grid over the anterior surface of the thorax. Incorporation of the lung inhomogeneity produced only small changes in the MCG's. Significantly different MCG's were produced by cardiac models which contained free versus fixed orientation current dipoles. A magnetic quasi-multipole expansion (MQME) differing from the classical magnetic multipole expansion, but having certain computational advantages, was developed. It was found that the first three terms in the MQME could represent MCG's to within 20%. A single current dipole model of cardiac excitation was shown to be inadequate for representing the precordial MCG's.
Semiautomatic construction of 3D medical image-segmentation processes

We describe a GUI-based system called INTERSEG that can define 3D radiological image-segmentation processes. Using INTERSEG's GUI interface, the user first defines interactively some problem cues, which specify a segmentation task. Then, INTERSEG uses the cues to automatically construct a process for the task. The process consists of automatic image-processing operations, such as image enhancement, image segmentation, shape analysis, and measurement. With other systems the user must resort to trial- and-error experimentation to construct such processes.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Nicotine Decreases Blood Alcohol Concentrations in Adult Rats: A Phenomenon Potentially Related to Gastric Function

Background: In spite of the fact that drinking and smoking often occur together, little is known about the pharmacokinetic interaction between alcohol and nicotine. Previous research in neonatal rats demonstrated that nicotine reduces blood alcohol concentrations (BACs) if alcohol and nicotine are administered simultaneously. However, it is unclear whether such a phenomenon can be observed in adult subjects, given the fact that there is an ontogenetic difference in alcohol metabolism. Methods: A range of nicotine doses (0, 0.25, 0.5, 1, 2, 4, and 6 mg/kg) were administered individually with an alcohol dose (4 g/kg) via intragastric (IG) intubation to adult female rats, and the resultant BACs were measured at various time points following drug administration. Furthermore, the hypothesis that nicotine's role in reducing BACs is mediated through factors related to gastric function was examined by comparing the resultant BACs after an IG intubation or intraperitoneal (IP) injection of alcohol. Results: The results from this study showed significant nicotine dose–related decreases in BACs with 0.5, 1, 2, 4, and 6 mg/kg doses of nicotine at the various time points assessed. This effect, however, occurred only when alcohol was administered via IG intubation, but not after an IP injection of alcohol. Conclusions: These results suggest that the nicotine-induced decrease in BAC may be related to gastric function. One possible explanation was related to nicotine's action in delaying gastric emptying. The longer the alcohol was retained in the stomach, the more likely that the alcohol would be metabolized by gastric alcohol dehydrogenase before its absorption into the bloodstream by the small intestine (the major site of alcohol absorption).
Zero-n¯ bandgap in photonic crystal superlattices

We demonstrate that photonic superlattices consisting of a periodic distribution of layers of materials with positive index of refraction and photonic crystal slabs that, at the operating frequency, have negative effective index of refraction present a photonic gap that corresponds to the frequency at which the spatial average of the refractive index distribution, taken over the unit supercell of the superlattice, vanishes. We also show that, unlike the Bragg gaps, the frequency of this zero-n¯ gap is invariant to the geometrical scaling of the superlattice or the direction of wave propagation in the superlattice.
Palladium-catalyzed reductive dehalogenation of dissolved chlorinated aliphatics using electrolytically-generated hydrogen

Recent studies have shown that reductive dehalogenation of chlorinated hydrocarbons by hydrogen occurs rapidly in the presence of a palladium catalyst. The speed and completeness of these reactions may offer advantages for groundwater remediation. A practical design challenge arises with the need to expeditiously saturate the aqueous phase with hydrogen. To address this, a two-stage treatment column (hydrogen generator and catalytic reactor) has been developed. The first stage consists of an undivided electrolyzer cell which generates hydrogen by electrolyzing the influent water. The second stage contains a catalyst bed of palladium metal supported on alumina beads. This reactor has been tested with groundwater containing various chlorinated aliphatics. Using a flow rate of 300 ml/min and a current of 4 amps under a potential of 8 volts, removal efficiencies greater than 95% were achieved for PCE, TCE, 1,1-DCE, and carbon tetrachloride with residence times on the order of 2 minutes. Chloroform and 1,2-DCA appear less susceptible to dehalogenation by this process. These results imply that dissolved oxygen present in solution does not completely inhibit reduction of the chlorinated hydrocarbons on the catalyst.
Capitalism Russian-Style

For a decade Russia has been dismantling communism and building capitalism. Describing a deeply flawed fledgling market economy, Capitalism Russian-Style provides a progress report on one of the most important economic experiments going on in the world today. It describes Russian achievements in building private banks and companies, stock exchanges, new laws and law courts. It analyzes the role of the mafia, the rise of new financial empires, entrepreneurs and business tycoons, and the shrinking Russian state. Thane Gustafson tells how the Soviet system was dismantled and the new market society was born. He argues that this new society is changing constantly, so that any assessment of success and failure would be premature. Identifying investment as vital to preserving Russia's status as a major industrial power, in his final chapter he examines the prospects for an economic miracle in Russia in the twenty-first century.
Urinary Neutrophil Gelatinase-Associated Lipocalin Predicts Mortality and Identifies Acute Kidney Injury in Cirrhosis

Background Kidney failure predicts mortality in patients with cirrhosis. Identification of kidney failure etiology and recognition of those at the highest mortality risk remains a challenge.
The anisotropic virial-biased sampling for Monte Carlo simulations in the isothermal—isobaric ensemble

The original virial-biased sampling of Mezei (1983, Molec. Phys., 37, 1779) that changes the simulation cell's volume isotropically has been generalized to anisotropical changes. Calculations on liquid water and the aqueous solution of the dimethylphosphate—sodium ion pair demonstrate the computational gains of the virial-biased techniques. The additional gain obtainable by the anisotropic biasing is also demonstrated.
Discovery of Protein-Protein Interaction Inhibitors of Replication Protein A.

Replication protein A (RPA) is a ssDNA binding protein that is essential for DNA replication and repair. The initiation of the DNA damage response by RPA is mediated by protein–protein interactions involving the N-terminal domain of the 70 kDa subunit with partner proteins. Inhibition of these interactions increases sensitivity toward DNA damage and replication stress and may therefore be a potential strategy for cancer drug discovery. Toward this end, we have discovered two lead series of compounds, derived from hits obtained from a fragment-based screen, that bind to RPA70N with low micromolar affinity and inhibit the binding of an ATRIP-derived peptide to RPA. These compounds may offer a promising starting point for the discovery of clinically useful RPA inhibitors.
Metric details for natural-language spatial relations

Spatial relations often are desired answers that a geographic information system (GIS) should generate in response to a user's query. Current GIS's provide only rudimentary support for processing and interpreting natural-language-like spatial relations, because their models and representations are primarily quantitative, while natural-language spatial relations are usually dominated by qualitative properties. Studies of the use of spatial relations in natural language showed that topology accounts for a significant portion of the geometric properties. This article develops a formal model that captures metric details for the description of natural-language spatial relations. The metric details are expressed as refinements of the categories identified by the 9-intersection, a model for topological spatial relations, and provide a more precise measure than does topology alone as to whether a geometric configuration matches with a spatial term or not. Similarly, these measures help in identifying the spatial term that describes a particular configuration. Two groups of metric details are derived: splitting ratios as the normalized values of lengths and areas of intersections; and closeness measures as the normalized distances between disjoint object parts. The resulting model of topological and metric properties was calibrated for 64 spatial terms in English, providing values for the best fit as well as value ranges for the significant parameters of each term. Three examples demonstrate how the framework and its calibrated values are used to determine the best spatial term for a relationship between two geometric objects.
Rama: an architecture for Internet information filtering

This paper describes Rama, a first generation experimental information retrieval and filtering system that attempts to recover useful information from various Internet sources including USENIX news and anonymous FTP servers. The focus of the Rama system to date has been on building a distributed query and information retrieval system, which provides an interface to heterogeneous information services. A user of Rama sends one or more asynchronous queries to a Rama server using existing SMTP e-mail clients. The server periodically searches local and remote Internet services. Searches are prefiltered with the use of timestamps. Data objects which are newer than the timestamp are then searched via a query mechanism which relies on a combination of vector-distance, pattern matching operands, and boolean operators. Results are weighted according to how closely they match queries and are posted via e-mail to the user. Input to the e-mail client can be further filtered — one can use the MH mail system and sort input by weight. Results indicate that the current system is useful and extensible. So far we have assumed that existing e-mail systems will be used for input and output and have not attempted to construct special client interfaces. Efforts are underway to extend the system with WWW searching capabilities and construct a special WWW oriented user-interface.
Activities of purine-metabolizing enzymes in human colon carcinoma cell lines and xenograft tumors

Abstract The activities of eleven enzymes of purine metabolism have been determined in extracts of four human colon carcinoma cell lines (clones A and D of the heterogeneous DLD-1 line, HCT-15 and DLD-2) in culture and as xenografts in nude mice. Activities of the enzyme adenine phosphoribosyltransferase (APRT), hypoxanthine phosphoribosyltransferase (HPRT), adenosine kinase, 5'-deoxy-5'-methylthioadenosine (MTA) phosphorylase, adenylate (AMP) kinase, guanylate (GMP) kinase, and nucleoside diphosphokinase (NDP kinase) changed little from line to line in vitro . Adenosine deaminase (ADA) activity varied more than 5-fold between HCT-15 and clone A cells. Purine nucleoside phosphorylase (PNP) activity was about 3-fold higher in DLD-2 cells than in the other three lines. Guanine deaminase (guanase) activity was 4- to 6-fold higher in clone A and D cells than in HCT-15 and DLD-2 cells. Xanthine oxidase was not detected in any of the lines grown in vitro or in vivo . The activity of APRT was highest in clone D xenografts. HPRT was lowest in DLD-2 tumors. ADA activity in DLD-2 tumors was more than 2-fold elevated over that for clone A and HCT-15 xenografts. PNP activity in clone A and HCT-15 xenografts was lower than that for clone D or DLD-2 tumors. Guanase was lower in HCT-15 and DLD-2 tumors than in those of clones A and D. Clone D tumor GMP kinase activity was elevated more than 4-fold above that for the other three tumors. The activity of NDP kinase was highest in clone D tumors. MTA phosphorylase activity was similar in all four xenografts. In general, the activity of a given enzyme was similar in cells growing in monolayer culture and as xenografts in nude mice (37/44 comparisons). Enzyme activities were also measured in normal human colon and compared to those in the xenografts. Where significant differences were seen, the values for normal tissue were almost always lower than those of the tumors. The striking similarities between the in vitro and in vivo enzymic profiles for each of these four human colon carcinoma lines indicate that, at least on this basis, responses of these cells to purines and purine analogs in the two-dimensional monolayer culture system should be predictive of in vivo responses.
Equations of state for the thermodynamic properties of R32 (difluoromethane) and R125 (pentafluoroethane)

Thermodynamic properties of difluoromethane (R32) and pentafluoroethane (R125) are expressed in terms of 32-term modified Benedict-Webb-Rubin (MBWR) equations of state. For each refrigerant, coefficients are reported for the MBWR equation and for ancillary equations used to fit the ideal-gas heat capacity and the coexisting densities and pressure along the saturation boundary. The MBWR coefficients were determined with a multiproperty fit that used the following types of experimental data: PVT: isochoric, isobaric, and saturated-liquid heal capacities; second virial coefficients; and properties at coexistence. The respective equations of stale accurately represent experimental data from 160 to 393 K and pressures to 35 MPa for R32 and from 174 to 448 K and pressures to 68 MPa for R125 with the exception of the critical regions. Both equations give reasonable results upon extrapolation to 500 K and 60 MPa. Comparisons between predicted and experimental values are presented.
SEPARATION OF CEREBROPROTEINS OF HUMAN BRAIN.

THE correlation of protein chemistry with complex functions of the brain has been hampered by the lack of basic information on the brain proteins. Extraction of brain proteins by techniques available so far has yielded usually less than 20 per cent of the total protein content of brain, and only up to 14 components have been demonstrable by electrophoresis1. Recent work in this laboratory has been directed to the definition of more quantitative methods for the extraction of brain proteins and for more adequate separation, physicochemical characterization, and histological localization by immunochemical methods2. We have observed that through a combination of mild buffered extraction, column chromatography on DEAE-cellulose and analysis of the carbohydrate content of each effluent tube, the presence of not less than 50 major chromatographic fractions can be distinguished (Fig. 1). Acrylamide gel-electrophoresis of each of these major fractions shows each to be heterogeneous. Accounting for overlap between chromatographic fractions, a minimum of 100 cerebroproteins from human grey matter have thus been observed. The total yield of protein in these experiments is 6.1 g/100 g wet wt. grey matter—a figure in range for previous figures for total unfractionated brain protein3. The previously known partially characterized protein fractions of brain1, together with the contribution by serum proteins from blood remaining in small vessels of grey matter, are not likely to account for more than a small percentage of this total yield. Thus, the bulk of the proteins here demonstrated apparently have not been separated or examined previously.
The role of iron and dissolved organic carbon in the absorption of ultraviolet radiation in humic lake water

Absorption of solar ultraviolet radiation (UVR) in aquatic ecosystems is primarily controlled by dissolved organic carbon (DOC). The role of iron (Fe) has also been suggested to contribute to UVR attenuation either directly or by interactions with DOC. Here we present findings from three laboratory manipulations of Fe and DOC on changes to the dissolved UVR absorption (ad,320) in a mid-latitude, dimictic, humic lake. In a laboratory simulation of lake turnover where anoxic, hypolimnetic water was oxygenated ad,320 significantly increased from 23.3 to 81.7 m−1 (p<0.0001). In a second laboratory experiment, addition of ferrous Fe to deoxygenated lake water increased ad,320 upon reoxygenation up to a concentration of 1.0 mg l−1 Fe, where a solubility saturation threshold may have been reached. In situ lake experiments were designed to simulate release of UV absorbing substances from anoxic sediments by placing 20-l carboys (open at the bottom, sealed at the top) onto the lake bottom. UV absorption at 320 nm increased over time for samples from within the experimental carboys. Finally, samples from several lake profiles and sediment experiments were analyzed for ad,320, total Fe, and DOC. UV absorption of dissolved substances at 320 nm and total Fe concentration both increased with depth, however DOC remained relatively constant over depth. Furthermore, total Fe and spectral slope showed tight coupling up to 1 mg l−1 total Fe in our survey analysis. Our results provide evidence for the importance of anoxic sediments as a source of ferrous iron and UV absorbing substances and suggest a role for ferric iron in increasing UVR and PAR absorption in lake water. We suggest that as this ferrous Fe oxidizes, its absorptive properties increase, and it may bind with dissolved organic matter, enabling it to remain in solution and thus increasing the dissolved absorption of lake water for extended periods of time.
A Popov-type stability criterion for control systems with natural pulse-width modulation†

A sufficient L 2(0, ∞) stability criterion for a class of pulse-width modulated control systems with ‘ natural sampling ’ of the ramp type is presented. The condition provides a straightforward geometric interpretation of the Popov plane.
The effect of external calcium and lanthanum on platelet calcium content and on the release reaction.

Abstract Calcium compartments in calf platelets were studied using a lanthanum washout procedure to distinguish between surface-bound calcium and intracellular calcium. The calcium content of calf platelets ranges from 20 to 60 nmol/109 platelets and is sensitive to the calcium concentration of the suspending medium. With 1 mM calcium in the medium, calcium uptake is rapid and reaches steady state within 1–2 min. Results obtained with the lanthanum procedure indicate that it is the surface compartment which is most affected by the extracellular calcium concentration. The surface compartment appears to be saturable and is highly exchangeable. Although the total calcium as well as the calcium content of the surface and internal compartments are variable, the ratio of calcium in either compartment to the total saturated calcium is quite constant. The data indicate that 68–85% of the platelet calcium is located internally. Thrombin produces an immediate release of platelet calcium and labeled serotonin and an increase in the 45Ca2+ uptake of both the surface and internal compartments. The release reaction is not dependent upon exogenous calcium or an influx of exogenous calcium since it occurs even in the presence of ethyleneglycol-bis-(β-aminoethylether) -N,N′- tetraacetic acid. Lanthanum, however, inhibits the release reaction possibly by blocking surface calcium site and reducing the mobility of endogenous platelet calcium.
Boundary-limited thermal conductivity of hcp 4 He

We have been able to grow constant-volume hcp $^{4}\mathrm{He}$ polycrystalline samples that exhibited Poiseuille flow of phonons as determined by thermal-conductivity measurements. These measurements were also extended well into the boundary scattering region to an order of magnitude lower temperature than previously reported. We find the conductivity is $k\ensuremath{\propto}{T}^{3}$ throughout this region. We were also interested in searching for any significant departures from this ${T}^{3}$ behavior that may have indicated the onset of specular reflection of phonons, or a supersolid transition. Such phenomena have been predicted for sufficiently low temperatures, and in view of our results, 30 mK would now appear to be an upper bound for any occurrence of these phenomena.
Acute bronchitis: results of U.S. and European trials of antibiotic therapy

Acute bronchitis, an illness frequently encountered by primary-care physicians, is an inflammation of the tracheobronchial tree that results from a respiratory tract infection. It is characterized by persistent cough and sputum production and is occasionally accompanied by fever and/or chest pain. Acute bronchitis may have a viral or bacterial origin and is often treated with antibiotics. Four clinical trials were conducted to compare high and low doses of loracarbef, a new oral beta-lactam antibiotic, with three agents commonly used to treat acute bronchitis: amoxicillin/clavulanate, cefaclor, and amoxicillin. Results of these studies indicated that loracarbef, 400 and 200 mg twice daily, had clinical and bacteriologic efficacy against the common respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella (Branhamella) catarrhalis that was comparable with that of the comparative agents. Loracarbef was as well tolerated as cefaclor and amoxicillin; moreover, it produced a significantly lower incidence of diarrhea than did amoxicillin/clavulanate. Loracarbef may be considered a safe and effective alternative agent for the treatment of patients with acute bronchitis.
Bisphosphonates and estrogens inhibit osteocyte apoptosis via distinct molecular mechanisms downstream of extracellular signal-regulated kinase activation.

Both estrogens and bisphosphonates attenuate osteocyte apoptosis by activating the extracellular signal-regulated kinases (ERKs). However, whereas estrogens activate ERKs via an extranuclear function of the estrogen receptor, bisphosphonates do so by opening connexin 43 hemichannels. Here, we demonstrated that the signaling events downstream of ERKs induced by these two stimuli are also distinct. Inhibition of osteocyte apoptosis by estrogens requires nuclear accumulation of ERKs and activation of downstream transcription factors. On the other hand, anti-apoptosis induced by bisphosphonates requires neither transcription nor ERK-dependent transcription factors. Instead, the effect of bisphosphonates is abolished when ERKs are restricted to the nucleus by blocking CRM1/exportin1-mediated nuclear protein export or by expressing nuclear-anchored ERKs, but it is unaffected in cells expressing cytoplasmic-anchored ERKs. Connexin 43/ERK-mediated anti-apoptosis induced by bisphosphonates requires the kinase activity of the cytoplasmic target of ERKs, p90RSK, which in turn phosphorylates the pro-apoptotic protein BAD and C/EBPβ. Phosphorylation of BAD renders it inactive, whereas phosphorylation of C/EBPβ leads to binding of pro-caspases, thus inhibiting apoptosis independently of the transcriptional activity of this transcription factor. Consistent with the evidence that estrogens and bisphosphonates phosphorylate diverse targets of ERKs, probably resulting from activation of spatially distinct pools of these kinases, the two agents had additive effects on osteocyte survival.
PERMANENT GROSS DEMONSTRATION OF THE CONDUCTION TISSUE IN THE DOG HEART WITH PALLADIUM IODIDE.

A permanent gross demonstration of dog cardiac conduction tissue was attempted unsuccessfully using standard glycogen and fat stains, experimentally induced lipogenesis, iodine, and the iodides of fluorescein, silver, and lead. Staining with insoluble sulfides was also unsuccessful. Permanent gross differentiation of the tissue can be accomplished with palladium iodide. The best fixative for minimum tissue distortion which stillpermits good differentiation is neutralized formol-saline. The opened and fixed heart is dipped in alcohol for 15 minutes prior to staining, then placed in an iodine-potassium iodide solution for two to five minutes. It is then rinsed in running water for one minute and transferred to a solution containing PdCl2 and HCl and left for ten minutes. Following the staining reaction, a differentiation lasting several hours is necessary. By this method, the entire sub-endocardial ramificationof the specialized tissue can be permanently demonstrated. Alternatively, the above process may be replaced by painting the endocardium with the various solutions, the results being equivalent but more localized.
Genetic algorithm optimization of a planar slot array using full wave method‐of‐moments analysis

Waveguide-fed slot arrays in standing wave mode have been employed successfully in space based remote sensing radars because of their high efficiency, ease of deployment and their ability to withstand the radiation environment. Although the bandwidth requirement in such systems is minimal, at Ka band and above manufacturing tolerances in the order of 1 mil (25 μm), achieved in the dip brazing process, may affect their performance. To produce designs that are less sensitive to manufacturing tolerance, genetic algorithm (GA) optimization is employed in conjunction with a full wave analysis utilizing the method-of-moments solution to the pertinent integral equations of slot apertures of a planar array. In this work, a single 8 × 10 sub-array of an interferometric antenna, proposed previously for a planetary mapping application, was investigated. The array was first designed by the Elliott's procedure and subsequently the design parameters were perturbed by GA optimization using the moment method analysis. The fitness parameter is a weighted function of return loss and gain over a number of frequencies in the operating band. A matching waveguide section consisting of inductive irises is also optimized using GA and mode matching technique. Optimum designs producing nearly constant gain and good return loss over 6% bandwidth are found to be less sensitive to manufacturing tolerance than the initial Elliott design. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.
Light-splitting method not new.

The News of the Week article “Light-splitting trick squeezes more electricity out of Sun's rays” (E. Kintisch, 3 August, p. [583][1]) conveys the erroneous impression that a spectral splitting solar concentrator using a dichroic mirror is a novel, unproven method to achieve high efficiency.
Pathophysiologic basis of autonomic ganglionated plexus ablation in patients with atrial fibrillation

The intrinsic cardiac autonomic nervous system (ganglionated plexuses [GP]) plays a significant role in the initiation and maintenance of atrial fibrillation (AF) in both experimental models and AF patients. Left atrial GP, located in epicardial fat pads and the ligament of Marshall, contain afferent neurons from the atrial myocardium and the central autonomic nervous system, efferent neurons (cholinergic and adrenergic neurons), and interconnecting neurons, which allow communication between GP. Stimulation of the GP produces both parasympathetic stimulation (markedly shortens action potential duration) and sympathetic stimulation (increases calcium transient) in the pulmonary vein (PV) myocardium and atrial myocardium. In a canine model, GP stimulation resulted in early afterdepolarizations, and calcium transient triggered firing in the adjacent PV and initiated AF. Fractionated atrial potentials (FAP) were consistently located in the left atrium close to the stimulated GP. Ablation of the stimulated GP eliminated the FAP surrounding the GP. In patients with paroxysmal AF, epicardial and endocardial high-frequency stimulation produced a positive vagal response (transient AV block during AF and hypotension), allowing the identification and localization of five major left atrial GP (superior left GP, inferior left GP, Marshall tract GP, anterior right GP, inferior right GP). High-density electroanatomic maps of the left atrium and PVs obtained during AF showed the FAP are located in four main left atrial areas (left atrial appendage ridge FAP area, superior-left FAP area, inferoposterior FAP area, anterior-right FAP area). All five GP are located within one of the four FAP areas. In 63 patients with paroxysmal AF, GP ablation alone (before PV antrum isolation) significantly decreased the occurrence of PV firing (47/63 patients before ablation vs 9/63 patients after ablation, P <.01). GP ablation also decreased the inducibility of sustained AF (43/63 patients vs 23/63 patients, P <.01) and markedly reduced or eliminated the left atrial FAP areas.
Laminar film condensation of a vapor containing a soluble, noncondensing gas

Abstract An integral theory is indicated for the effect of a soluble, noncondensable gas on the laminar film condensation of stagnant vapor on a vertical surface, and by approximations on the results a compact definition is given for saturated air-steam mistures. Also, approximations on the theory itself yield a simple result for any vapor-gas combination in which the gas fraction is low, the gas is heavier than the vapor, and the Lewis number is near unity. The effect of gas-solubility in the condensate is found to be fully negligible for air-steam mixtures and quite small even for carbon dioxide-steam. Additional experimental results are given for steam and various gases which generally support the theory.