cssi/SciSciGPT-SciSciNet huggingface dataset:
Atmospheric pressure plasma activation of plastics and composites for improved adhesion

Summary form only given. Atmospheric pressure plasma treatment is a key process for surface preparation prior to adhesive bonding of plastics and composites for use in the aerospace, automotive, medical device, and electronics industries. A review is presented on methods for surface preparation of polymers and composites using low-temperature, atmospheric pressure radio frequency helium and oxygen plasmas. This is a promising technique for replacing traditional methods of surface preparation such as peel ply and abrasion. The plasma source generates an afterglow containing ∼1×1017 cm−3 oxygen atoms, ∼1×1017 cm−3 metastable oxygen molecules (1Δ g ), and ∼4×1014 cm−3 ozone molecules. With sufficient exposure to the afterglow, polymer and composite surfaces are fully activated such that when bonded and cured with epoxy adhesives, they undergo 100% cohesive failure. Depending on the material, lap shear strength and delamination resistance can be increased over 50% from that activated by solvent wiping or abrasion. Surface analysis by water contact angle and AFM indicates that there is no correlation between bond strength and surface energy or surface roughness. Instead, bond strength correlates with the fraction of the polymer surface sites that are oxidized and converted into carboxylic acid groups, as determined by x-ray photoemission and infrared spectroscopy. Polymers with aromatic groups in the backbone are especially suitable for activation with the atmospheric pressure plasma. The activation mechanism, surface characterization results, and bonding strength improvement are discussed in detail.
Functional neuroimaging abnormalities in idiopathic generalized epilepsy

Magnetic resonance imaging (MRI) techniques have been used to quantitatively assess focal and network abnormalities. Idiopathic generalized epilepsy (IGE) is characterized by bilateral synchronous spike–wave discharges on electroencephalography (EEG) but normal clinical MRI. Dysfunctions involving the neocortex, particularly the prefrontal cortex, and thalamus likely contribute to seizure activity. To identify possible morphometric and functional differences in the brains of IGE patients and normal controls, we employed measures of thalamic volumes, cortical thickness, gray–white blurring, fractional anisotropy (FA) measures from diffusion tensor imaging (DTI) and fractional amplitude of low frequency fluctuations (fALFF) in thalamic subregions from resting state functional MRI. Data from 27 patients with IGE and 27 age- and sex-matched controls showed similar thalamic volumes, cortical thickness and gray–white contrast. There were no differences in FA values on DTI in tracts connecting the thalamus and prefrontal cortex. Functional analysis revealed decreased fALFF in the prefrontal cortex (PFC) subregion of the thalamus in patients with IGE. We provide minimum detectable effect sizes for each measure used in the study. Our analysis indicates that fMRI-based methods are more sensitive than quantitative structural techniques for characterizing brain abnormalities in IGE.
Ovarian steroidogenesis in vitro during the first month posthatching in the domestic chick: Gonadotropin responsiveness and [3H]progesterone metabolism

Abstract Ovarian steroidogenesis was examined in domestic chicks during the first month post-hatching. In vitro production of androstenedione during a 4-hr incubation was enhanced in a dose-dependent manner by 0.1–100 ng/ml of chicken LH (cLH). The greatest response was observed in ovaries from Day 1 chicks (eightfold), but cLH was also effective in Day 7, 14, 21, and 28 ovaries (three-to sixfold increase). Estrogen production in response to cLH was increased significantly only in Day 1 and 7 ovaries. A similar trend in androstenedione and estrogen production was seen in response to 8-bromo cAMP, oLH, and oFSH. In an additional experiment, in vitro metabolism of [3H]progesterone by ovaries from Day 1, 7, 14, and 21 chicks was examined during a 4-hr incubation. The major metabolite, comprising 18–19% of the radioactivity, cocluted with 5β-pregnan-3,20-dione. This is the first report of gonadotropin-stimulated steroidogenesis and progesterone metabolism in the chick during the first month post-hatching. The results show that (1) the responsiveness to gonadotropins decreases during this period and (2) the profile of [3H]progesterone metabolism does not resemble that seen in adult granulosa and theca cells.
Discussion of “Development of a Substructure Instrumentation System at the New I-10 Twin Span Bridge and Its Use to Investigate the Lateral Behavior of Batter Piles”

The interpretation of the load test results presented in the paper may mislead design engineers to an unconservative estimation of design loads for bridge subfoundations. Lack of error checking in the authors’ finite element analysis (FEA) model might have resulted in invalid assessment of the validity of the FB-MultiPier FEA software program.
Volatile cephalic substances of the stingless bees, Trigona mexicana and Trigona pectoralis

Abstract Extracts of the heads of the stingless bees, Trigona mexicana and T. pectoralis, contain mixtures of compounds that are identifiable by gas chromatography and mass spectrometry. These compounds form homologous series of aliphatic alcohols and ketones with an odd number of carbon atoms and functional groups at the 2-position. The alcohols and the ketones range from 7 to 17 carbon atoms. Benzaldehyde and a nitrogen containing compound are also present in the mixtures. The series of compounds from the two species are nearly identical qualitatively. They differ in the absence of 2-undecanol and 2-pentadecanol from the extracts of T. mexicana and T. pectoralis, respectively. The highest concentration of material is found in the 7-carbon fraction in T. mexicana and in the 13 to 15 carbon range in T. pectoralis. There is a major difference in the relative concentration of 2-heptanol and 2-heptanone in the two species with the concentration of the alcohol being one-fourth that of 2-heptanone in T. mexicana and ten times greater than the ketones in T. pectoralis. Both the alcohols and ketones are alarm pheromones. The alcohols are more active in inducing attack by the bees than are the ketones, but a mixture of the ketones and benzaldehyde was very active.
Hypericin and photodynamic therapy decreases human pancreatic cancer in vitro and in vivo

Background. The treatment of pancreatic cancer has remained dismal despite advances in medical and surgical care. Recent preclinical data have revealed that hypericin, a photochemical dye, is activated by green light and generates toxic radical species in tumors. We hypothesized that interstitial hypericin and laser phototherapy would decrease pancreatic cancer growth. Methods. MiaPaCa-2 and PANC-1 cells were grown in tissue culture. In vitro experiments were performed with addition of 10 μg of hypericin/500,000 cancer cells. Cells were incubated with hypericin for 2 h. Cells were then exposed to KTP532 green laser light for 1 min at 0.6 W using a cylindrical diffuser tip. Cell growth was measured by MTT assay 24 h after laser treatment, N = 12. MiaPaCa-2 cells were implanted subcutaneously and orthotopically in pancreas of nude mice. After 5 weeks, both tumors were injected with 100 μg of hypericin followed by insertion of a cylindrical diffuser tip into the tumor center. Mice received 200J KTP laser light at 1.0 W in two sites. Tumors were measured before and 4 weeks after laser treatment. Results. Both in vitro and in vivo mice data showed a significant decrease in growth of pancreatic cancer. Pancreatic cancer cell growth was suppressed by 66.1 ± 0.2%, n = 12, P < 0.01, ANOVA. Subcutaneous shoulder tumors were suppressed by 91.2 ± 2.3%, n = 12, P < 0.001, and orthotopically grown pancreatic tumors were suppressed by 42.2 ± 8.1%, n = 12, P < 0.05, compared to pretreatment sizes. Data expressed as percentage reduction vs paired controls in the MTT assay and vs pre-photodynamic therapy in mice experiments. Paired Student's t tests were performed vs pretreatment sizes. Conclusion. Both in vitro and in vivo results revealed a significant decrease in pancreatic cancer cell growth. Laser or dye alone had no effect, indicating that intratumor hypericin and laser therapy may prove useful in unresectable pancreatic cancer.
Effect of Plasma Volume Loss during Graded Exercise Testing on Blood Lactate Concentration

Previous studies have shown that plasma volume (PV) loss can be a confounding variable in the interpretation of changes in blood constituents. We examined the effect of PV loss on three features of the blood lactate versus work-rate relationship, namely, slight blood lactate increase during the early stages of graded exercise testing (GXT); work rate at the onset of a systematic increase in blood lactate, i.e., lactate threshold (LT); and work rate at a blood lactate concentration of 4 mM, i.e., onset of blood lactate accumulation (OBLA). Fourteen subjects underwent cycle ergometer GXT. Blood samples were obtained at rest and at the end of each 3-min work-rate increment and analyzed for hematocrit and lactate concentration. For exercise levels up to and including LT, PV loss was relatively stable at approximately 2.8%. Beyond LT, PV loss accelerated. From the first work rate to LT, blood lactate concentration uncorrected for PV loss increased 0.24 ± 0.07 mM (P < 0.05). After correction for PV loss, the increase was 0.21 ± 0.08 mM (P < 0.05). These mean increases were not significantly different from each other. For the four exercise levels above LT common to most subjects, PV-corrected lactate values were significantly lower than uncorrected values. Correction of lactate values for PV loss did not alter LT for any subject, but it did result in a significant increase in OBLA. Thus, PV loss has the potential to be a confounding variable for the interpretation of blood lactate parameters that are determined at exercise levels above LT.
Control of transmission of HIV and other bloodborne pathogens in biomechanical cadaveric testing

The Bioengineering Center at Wayne State University uses universal blood and body fluid precautions when handling human cadavers in bio-mechanical testing. Our infection control protocol largely follows the precautions outlined by the Centers for Disease Control (CDC). In addition, we screen each cadaver for the human immunodeficiency virus (HIV) and the hepatitis B virus (HBV) before accepting a cadaver for biomechanical tests. This paper discusses acquired immunodeficiency syndrome (AIDS) and infection control guidelines by addressing the following: (a) what is AIDS? (b) How infectious is the HIV virus, which causes AIDS? (c) What precautions should be taken in cadaveric testing to safeguard against HIV and other bloodborne pathogens? The infection control procedures presented in this paper can be adapted to whole-body cadaveric testing or to the testing of tissue specimens.
T-Junction grain boundaries in block copolymer-homopolymer blends

T-junction grain boundaries were studied in a blend of polyisoprene homopolymer and a single graft block copolymer I2S with two equal length blocks of polyisoprene and one arm of polystyrene linked at a common junction point. The overall polyisoprene volume fraction in the blend was 0.52, and its equilibrium morphology was lamellar. While T-junctions were previously observed to be quite rare compared to other tilt grain boundary morphologies such as chevrons and omegas, they were found in abundance in the blend used in the current study. The T-junctions in the blend show a number of distinctive characteristics including enlarged semicylindrical end caps terminating polystyrene lamella and an increase in the spacing of the lamella as they near their termination at the T-junction. Simple free energy calculations show that the homopolymer present in the blend stabilizes the cylindrical curvature of the end caps, rendering the T-junction morphology more stable in blends than in neat block copolymers. This agr...
Cholinergic Receptor I. Cholinomimetic Activities of Some Analogs of cis-2-Methyl-4-dimethylaminomethyl-1,3-dioxolane Methiodide

The cholinomimetic activities of acetylcholine, cis -2-methyl-4-dimethylamino-methyl-1,3-dioxolane methiodide, N -methyl-6,8-dioxa-3-azabicyclo[3.2.1]octane methiodide, and N -methyl-7,9-dioxa-3-azabicyclo[4.2.1]nonane methiodide have been compared and an interpretation of their relative activities in terms of a conformation of receptor-bound cholinomimetic molecules has been put forward. N -Methyl-7,9-dioxa-3-azabicyclo[4.2.1]nonane methiodide has been shown to have some acetylcholine releasing activity.
Studies of resistance of fetal mofse tissues in culture to Coxsackie grofp a viruses

Abstract Mofse fetuses, in utero , were shown to be susceptible to infection by Coxsackie A13 virus. Minced tissues derived from infected fetuses also were shown to be capable of A13 virus production when placed in culture. However, cultures of cells as monolayers or as minced tissues, which were derived from normal fetal mice, were fofnd to be refractory to infection by Coxsackie A13 or A18 viruses. Results of further experiments showed that cultured fetal mofse cells and even preparations of freshly minced fetal tissues were unable to attach significant amofnts of A13 or A18 viruses. The ability of minced fetal mofse tissues to attach virus was not enhanced by (1) addition to the system of serum obtained from normal, pregnant, or postpartum mice, (2) addition of serum of human, calf, or rabbit origin; or (3) placement of the minced tissues in the peritoneal cavity of an adult mofse. Attempts to demonstrate the presence of an inhibitor of viral receptor activity in the minced tissues were unsuccessful. Measurements, by mofse infectivity assays and by plaque assays in HeLa cells, of A13 virus not removed from suspension by three consecutive applications of freshly prepared minced fetal mofse tissue, failed to reveal heterogeneity of the virus population. The results suggested that the procedures employed to remove fetal mofse cells from their native environment rendered the cells incapable of attaching A13 and A18 viruses and thereby prevented viral replication.
Physical adsorption of rare gas on terrigenous sediments

Heavy rare gases adsorption on terrigenous sediments, comparing earth atmospheric composition with meteoritic planetary primordial component
Data-Based Nonparametric Estimation of the Hazard Function with Applications to Model Diagnostics and Exploratory Analysis

Two general classes of nonparametric kernel estimators of the hazard function are introduced, which include both a 1-parameter estimator and a more complex 3-parameter estimator. In addition, employing the idea of cross-validation, the authors present a data-based algorithm for smoothing parameter selection. The article compares the data-based 1and 3-parameter estimators in a simulation experiment to the maximum likelihood estimator assuming the correct failure distribution and censoring mechanism. The 3-parameter estimator is found to perform well over a wide range of settings. On the average, the estimator recovers the shape of the underlying failure hazard and is competitive with the parametric estimator over a subset of the positive half line. Two examples illustrate possible uses of the nonparametric estimators.
Reconciling frequency selectivity and phase effects in masking.

The effects of auditory frequency selectivity and phase response on masking were studied using harmonic tone complex maskers with a 100-Hz fundamental frequency. Positive and negative Schroeder-phase complexes (m+ and m−), were used as maskers and the signal was a long-duration sinusoid. In the first experiment, thresholds for signal frequencies of 1 and 4 kHz were measured as a function of masker bandwidth and number of components. A large difference in thresholds between the m+ and m− complexes was found only when masker components were presented ipsilateral to the signal over a frequency range wider than the traditional critical band, regardless of the absolute number of components. In the second experiment, frequency selectivity was measured in harmonic tone complexes with fixed or random phases as well as in noise, using a variant of the notched-noise method with a fixed masker level. The data showed that frequency selectivity is not affected by masker type, indicating that the wide listening bandwid...
Cytomegalovirus infection in heart transplant recipients: preliminary results of a controlled trial of intravenous gamma globulin.

Cytomegalovirus (CMV) infection is a major problem during the first twelve weeks after cardiac transplantation. Reactivation of endogenous virus, blood transfusion, and the transplanted heart are sources for CMV infection. Not only can disseminated CMV infection contribute directly to mortality, but CMV infection predisposes to superinfection with bacterial and fungal pathogens. Studies in mice, the premature neonate, and bone marrow transplant recipients suggest that passive immunization with CMV antibody has a modifying effect on CMV infection. By prophylactic administration of intravenous immune globulin in a controlled randomized fashion to cardiac transplant recipients we will address the question of whether passively acquired antibody prevents or modifies infection with CMV or other viral, bacterial, and fungal infections. Thirteen patients undergoing cardiac transplantation at Stanford University were randomized to receive or not receive intravenous immune globulin (IGIV) at a dose of 20 ml/kg twenty-four hours post transplantation and then weekly thereafter for a period of 10 weeks. Six patients seronegative for CMV antibody were randomized separately from seven who were seropositive for CMV antibody. Seven patients randomly selected from these two groups received IGIV. In patients seronegative for CMV, administration of IGIV resulted in serum titers of 1:10,000–1:30,000 measured by radioimmunoassay. Antibody titers were maintained at levels of 1:10,000 to 1:30,000 throughout the 10 week period post transplantation. Antibody remained detectable up to 8 weeks after the last infusion. No significant increases in CMV antibody levels were detectable after IGIV administration in patients seropositive for CMV antibody prior to transplantation. The administration of IGIV in thirty-two large and repeated doses was safe and well tolerated in cardiac transplant recipients. Serum levels of CMV antibody comparable to those observed in normal CMV seropositive individuals were achieved in CMV seronegative transplant recipients and were maintained throughout the period of greatest risk for CMV infection.
Neighborhood Characteristics as Predictors of Male to Female and Female to Male Partner Violence

This article examines the association between neighborhood characteristics at the census tract-level, couples' perceived neighborhood social cohesion and informal social control, and male-to-female (MFPV) and female-to-male (FMPV) partner violence in the United States. Data come from a second wave of interviews (2000) with a national sample of couples 18 years of age and older who were first interviewed in 1995. The path analysis shows that poverty is associated with perceived social cohesion and perceived social control as hypothesized. However, there is no significant mediation effect for social control or social cohesion on any type of violence. In the path analysis, Black ethnicity is associated with social cohesion, which is associated with MFPV. Intimate partner violence (IPV), as a form of domestic violence, may not be as concentrated in high-poverty neighborhoods as criminal violence. IPV may be more determined by personal and dyadic characteristics than criminal violence.
Hypercube embedding heuristics: an evaluation

The hypercube embedding problem, a restricted version of the general mapping problem, is the problem of mapping a set of communicating processes to a hypercube multiprocessor. The goal is to find a mapping that minimizes the length of the paths between communicating processes. Unfortunately the hypercube embedding problem has been shown to be NP-hard. Thus many heuristics have been proposed for hypercube embedding. This paper evaluates several hypercube embedding heuristics, including simulated annealing, local search, greedy, and recursive mincut bipartitioning. In addition to known heuristics, we propose a new greedy heuristic, a new Kernighan-Lin style heuristic, and some new features to enhance local search. We then assess variations of these strategies (e.g., different neighborhood structures) and combinations of them (e.g., greedy as a front end of iterative improvement heuristics). The asymptotic running times of the heuristics are given, based on efficient implementations using a priority-queue data structure.
Glass-Indurated Quartz Gouge in Sliding-Friction Experiments on Sandstone

Three types of glass-indurated quartzose gouge are recognized (optically and with SEM) along the sliding surfaces of 29° to 45° precut specimens of dry Tennessee Sandstone, deformed at 0.14- to 5.0-kb confining pressure, shortening rates of 10 to 10−4/sec, 24° to 410°C, and with displacements <1.0 cm. “Welded clumps” form in tests at 24° and ≤1.0-kb confining pressure. The welded portions of each clump are composed of quartz fragments indurated by an optically isotropic matrix (index of refraction of 1.500 to 1.520) that supports brittle fracture and is probably glass. As the temperature of the experiments is increased, “fibrous patches” become widespread. These patches are vesicular and conspicuously striated, they stand out in optical relief on top of quartz grains, they contain ordered microfractures that suggest extension along the sliding direction, and their “lee” edges are marked by very fine fibers that emanate from tapered bodies rooting in the patches. At high pressures and low temperatures, “welded plates” cover much of the sliding surfaces. These are fractured and striated, but nonfibrous. The glass indicates that local silica–fusion temperatures occurred during frictional sliding. The change in the nature of the gouge is accompanied by a change in sliding mode from stick-slip (25°C) to episodic (150° to 250°C) to stable sliding (410°C), and by a progressive increase in the coefficient of sliding friction from 0.58 at 25°C, to 0.72 at 410°C.
Cocaine‐related intracranial hemorrhage. Report of nine cases and review

— Nine cases of intracranial hemorrhages related to cocaine usage are presented. Another 5 cases from the literature are reviewed. The relationship between severe cocaine-induced hypertension, and the development of subarachnoid or intracerebral hemorrhages is noted, and apparently is related to sudden transient increases of blood pressure related to cocaine use.
Native-state conformational dynamics of GART: A regulatory pH-dependent coil–helix transition examined by electrostatic calculations

Glycinamide ribonucleotide transformylase (GART) undergoes a pH-dependent coil–helix transition with pKa ∼ 7. An α-helix is formed at high pH spanning 8 residues of a 21-residue-long loop, comprising the segment Thr120–His121–Arg122–Gln123–Ala124–Leu125–Glu126–Asn127. To understand the electrostatic nature of this loop–helix, called the activation loop–helix, which leads to the formation and stability of the α-helix, pKa values of all ionizable residues of GART have been calculated, using Poisson–Boltzmann electrostatic calculations and crystallographic data. Crystallographic structures of high and low pH E70A GART have been used in our analysis. Low pKa values of 5.3, 5.3, 3.9, 1.7, and 4.7 have been calculated for five functionally important histidines, His108, His119, His121, His132, and His137, respectively, using the high pH E70A GART structure. Ten theoretical single and double mutants of the high pH E70A structure have been constructed to idey pairwise interactions of ionizable residues, which have aided in elucidating the multiplicity of electrostatic interactions of the activation loop–helix, and the impact of the activation helix on the catalytic site. Based on our pKa calculations and structural data, we propose that: (1) His121 forms a molecular switch for the coil–helix transition of the activation helix, depending on its protonation state; (2) a strong electrostatic interaction between His132 and His121 is observed, which can be of stabilizing or destabilizing nature for the activation helix, depending on the relative orientation and protonation states of the rings of His121 and His132; (3) electrostatic interactions involving His119 and Arg122 play a role in the stability of the activation helix; and (4) the activation helix contains the helix-promoting sequence Arg122–Gln123–Ala124–Leu125–Glu126, but its alignment relative to the N and C termini of the helix is not optimal, and is possibly of a destabilizing nature. Finally, we provide electrostatic evidence that the formation and closure of the activation helix create a hydrophobic environment for catalytic-site residue His108, to facilitate catalysis.
THE USE OF SINKING FUNDS IN PREFERRED STOCK ISSUES

By H. LAWRENCE WILSEY Cornell University All war and postwar periods are characterized by dynamic business and financial conditions. As the conditions become more and more dynamic, changes are accentuated that previously had been slowly taking place, and changes arise that previously had not existed. Experience is gained at a far more rapid pace than during periods of business stagnation, and the adjustments resulting from the increase in experience and knowledge take place in a far shorter period of time. At the present time one of these changes that has become significant in the field of corporation finance is the growing use of sinking fund provisions in preferred stock issues to provide for their retirement. While sinking funds have long been extensively used in bond retirement, their use in conjunction with preference shares, though not a newphenomenon, has grown to its present position at a markedly increasing rate only during the past few years. Of the preferred stocks initially offered during the past six years that were listed for trading on the New York Stock Exchange on January 1, 1947, over half contain sinking fund provisions. Taking the form of a contract between the corporation and the stockholders, the sinking fund provision generally provides that the corporation is to allocate earnings each year to a fund to be used to redeem a portion of the outstanding preferred stock. The ultimate goal of such a program is, of course, the removal of the preferred stock from the capital structure. What effect does this type of a provision have upon the nature of the preferred stock itself ? Historically the stockholders have been the owners of the corporate firm, and the bondholders, if any, have been the creditors. Preferred stock grew up between the pure common stock and the bond as a hybrid type. Sometimes it has possessed most of the rights of owners with many of the preferences over the common stock that had previously been retained for creditors, but more frequently, through the use of numerous limiting clauses in the stock contract, it has possessed few of either. As an ownership security preferred stock was at first looked upon, as common stock long had been, as an evidence of ownership that was to remain outstanding as long as the corporation retained its existence. While bonded indebtedness was generally designed to reach maturity after a specified period of time, ownership continued in the firm until the firm was itself liquidated. The com-
NEWS ABOUT SCIENCE: CHANNELS, AUDIENCES, AND EFFECTS

UST two weeks after Russian scientists launched the first earth satellite in October of 1957, a former Assistant Secretary of Defense suggested four steps as necessary for the United States "to go back and win the race for scientific supremacy." Three of these recommendations involved the American public-increasing their acceptance of the value of basic research, convincing them that universities deserve more support in training scientists, and giving them a more favorable picture of scientific work and the people who do it. These steps would require extensive use of the mass media, and they raise some question as to the possibilities for an improved public reaction to science news. We know how to direct messages effectively to specific target audiences, but we know less about efficient transmission of information to the national population. Six months before the launching of Sputnik I, a national study focusing on science was conducted for the National Association of Science Writers.' Six months after the launching, the field staff of the Survey Research Center interviewed a probability sample of 1,547 adults to obtain comparative data on extent and accuracy of satellite information, patterns of news intake, and attitudes toward science and scientists. The dramatic impact of the first satellite launching, heightened by its political importance and the tremendous volume of news related to it, created a situation which is hardly typical of the average scientific news event. However, habitual mass media usage patterns, the existing channels of interpersonal communication, and the personal "filters" through which information is received were factors common to other
When does pathogen evolution maximize the basic reproductive number in well-mixed host–pathogen systems?

Pathogen evolution towards the largest basic reproductive number,\(\mathcal R _0\), has been observed in many theoretical models, but this conclusion does not hold universally. Previous studies of host–pathogen systems have defined general conditions under which \(\mathcal R _0\) maximization occurs in terms of \(\mathcal R _0\) itself. However, it is unclear what constraints these conditions impose on the functional forms of pathogen related processes (e.g. transmission, recover, or mortality) and how those constraints relate to the characteristics of natural systems. Here we focus on well-mixed SIR-type host–pathogen systems and, via a synthesis of results from the literature, we present a set of sufficient mathematical conditions under which evolution maximizes \(\mathcal R _0\). Our conditions are in terms of the functional responses of the system and yield three general biological constraints on when \(\mathcal R _0\) maximization will occur. First, there are no genotype-by-environment interactions. Second, the pathogen utilizes a single transmission pathway (i.e. either horizontal, vertical, or vector transmission). Third, when mortality is density dependent: (i) there is a single infectious class that individuals cannot recover from, (ii) mortality in the infectious class is entirely density dependent, and (iii) the rates of recovery, infection progression, and mortality in the exposed classes are independent of the pathogen trait. We discuss how this approach identifies the biological mechanisms that increase the dimension of the environmental feedback and prevent \(\mathcal R _0\) maximization.
The Revolution Will Not Be Televised: Introduction to the Special Issue on Marketing Science and the Internet

There is a revolution happening-a startling and amazing revolution that is altering everything from our traditional views of how advertising and communication media work to how people can and should communicate with each other. That revolution is the Internet-the massive global network of interconnected packet-switched computer networks-and as the most important innovation since the development of the printing press, the Internet has the potential to radically transform not just the way individuals go about conducting their business with each other, but also the very essence of what it means to be a human being in society. Since the introduction of the first graphicallyoriented Web browser, Mosaic, in 1993, the Internet has experienced phenomenal growth, both in terms of the number of computers and devices connected to it and the number of individuals and firms providing and accessing content on it Hoffman et al. 2000. The first significant commercial activity appeared on the Web by 1994and in the ensuing five years, the commercialization of the Internet has exploded. There are now very few countries and territories left in the entire world that do not have at least one host computer connected to the Internet Rutkowski 1999. At the same time, electronic commerce, as a research area, a business, and, indeed, an entire new industry, is still very much in its infancy. There is much confusion and complexity and not nearly enough solid information.
The structure and thermodynamics of binary microclusters: A Monte Carlo simulation

Abstract The Monte Carlo computer simulation technique of classical statistical mechanics is employed to determine the structure and thermodynamics of binary microclusters of Lennard-Jones atoms as a function of cluster size, composition and temperature. Further, amorphous microclusters are prepared by a Monte Carlo quench, and their structural properties are examined. The properties of interest include the internal energy, instantaneous “snapshot” pictures of the microcluster's atomic configuration, and the single-particle and pair distribution functions. The Lennard-Jones potential parameters are chosen to model Ar 13 , Ar 7 Kr 6 , Ar 36 Kr 19 and Ar 19 Kr 36 , as well as to crudely model the bimetallic clusters of Cu 19 Ni 36 , Cu 19 Ru 36 and Cu 19 Os 36 . A large variety of interesting features associated with these systems are described.
Erratum to “The computational power of Benenson automata” [Theoret. Comput. Sci. 344 (2005) 279-297]

We erroneously claim that Lemma 5.1 applies to both non-deterministic and deterministic Benenson automata, while it applies only to deterministic ones. The following corrected lemma holds for both deterministic and non-deterministic Benenson automata. It also exponentially improves on the dependence on D for both for circuit depth and size compared to the paper version. Note that compared with the paper version, the circuit depth has an extra logarithmic dependence on n, and the circuit size has an extra linear dependence on n. Theorem 3.2 follows from Lemma 5.1(corrected) as before, by taking D = O(1), S = O(log n), and L = poly(n). Lemma 5.1 (Corrected). A function f : {0, 1}n → {0, 1} computed, possibly non-deterministically, by a Benenson automaton (S,D, L, Σ, n, σ , R) can be computed by a O(log(L/D) logD + log2 D + log n) depth, O(LD2 logD + LDn) size circuit.
Regularity of the invariant measure and of the density of states in the one-dimensional Anderson model

Abstract Let H = − 1 2 Δ + V on l2(Z), where V(x), xϵZ are i.i.d.r.v.'s with common probability distribution μ. Let h(t) = ∝ e−itvdμ(v), let N(E) be the integrated density of states, and let νE be the invariant measure at energy E. It is proven: 1. 1. Let h be d-times differentiable on (0, + ∞) with bounded derivatives such that h(j)(t) → 0 as t → +∞ for j = 0, 1, …, d. Then: (i) N(E) is a Cd function. (ii) If d ⩾ 3, νE is absolutely continuous for all EϵR and dν E dx is of class C [ (d − 1) 2 ] − 1 jointly in E and x. 2. 2. Let h be differentiable on (0, +∞) with h (j) (t) = O(e −b¦t¦ ) for j = 0, 1 and some b > 0. Then dν E dx is jointly analytic in E and x.
Susceptibility of thirteen stored product beetles to entanglement by Trogoderma hastisetae

Abstract Factors affecting the susceptibility of adults of 13 and larvae of 2 species of stored product beetles to entanglement by Trogoderma larval hastisetae were studied. The length, diameter, shape, density, and angle of the test insects' setae probably affected susceptibility. The setae on the hindwings of Trogoderma adults were susceptible to permanent hastisetal attachment which prevented normal closure of elytra over the hindwings. Sitophilus oryzae (L) and Cryptolestes pusillus (Schonherr) were susceptible, with 93 and 83% mortality, respectively, at the end of 72 hr exposure. Tribolium castaneum (Herbst), T. confusum (duVal), Gibbium psylloides (Czenpinski), and Tenebroides mauritanicus (L.) resisted hastisetal attachment. Scanning electron micrographs revealed the attachments of heads of hastisetae to setae of several beetles exposed to larval Trogoderma .
A FACTORIAL STUDY OF THE ENERGY AND MOISTURE TRANSFER PROCESSES AT THE LAND SURFACE

Abstract Interactions of the energy and moisture transfer processes at the land surface are investigated using factorial experimentation on a simple non-vegetated model. The model is constructed from energy and moisture balance equations at the land surface. Parameterizations from general circulation models are used to describe the model components. The factorial analysis is performed on two differently parameterized versions of the model in both steady-state and dynamic models. Results indicate that the runoff parameterization plays a critical role in determining soil moisture. Also, the inclusion of a second soil layer appears to have an attenuating effect on the model's temperature and soil moisture response times, whereas the choice of top layer depth substantially affects the diurnal surface temperature variation. It is also found that the temperature response time is correlated with and a strong function of the moisture response time. These results are useful in understanding the variation in regional climate predictions documented in recent general circulation model studies. In addition, factorial designs are shown to be an effective tool for analyzing individual parameter sensitivity and parameter interactions in models with a large number of factors.
Involvement of the midbrain reticular formation in self-injurious behavior, stereotyped behavior, and analgesia induced by intranigral microinjection of muscimol.

Abstract Bilateral microinjection of muscimol (60 ng), a γ-aminobutyric acid (GABA) agonist, into the central region of the substantia nigra (pars reticulata) produced self-injurious behavior (SIB), stereotyped behavior and analgesic-like effects in rats. Bilateral electrolytic lesions of the midbrain reticular formation ventrolateral to the periaqueductal gray matter completely blocked the SIB but had little effect on stereotyped behavior produced by intranigral muscimol. Lesions of the midbrain reticular formation reduced the antinociceptive effect of intranigral muscimol on the tail-flick but not on the hot-plate test. Bilateral microinjection of muscimol (10–100 ng) into the midbrain reticular formation produced intense stereotyped behavior and had an analgesic-like effect on the hot-plate test but not on the tail-flick test. Stereotyped behavior appeared to interfere with the paw-lick response on the hot-plate test. These data suggest that the antinociceptive effect of intranigral muscimol on the tail-flick test is mediated by fibers that project to or pass through the midbrain reticular formation and that analgesia may play an important role in muscimol-induced SIB. The midbrain reticular formation does not appear to be involved in the stereotyped behavior produced by intranigral muscimol.
Alzheimer's disease: a re-examination of the amyloid hypothesis

Alzheimer's disease (AD) is a neurodegenerative disorder of the brain characterized by the presence of neuritic amyloid plaques and neurofibrillary tangles. Although it most frequently occurs in the elderly, this disorder also afflicts younger patients. The majority of AD cases are late in onset, lack an obvious genetic etiology and are characterized as sporadic, whereas a small percentage of cases are early in onset and segregate strongly within families (FAD), suggesting a genetic etiology. During the past decade it has become evident that the clinical and histopathological phenotypes of this disease are caused by heterogeneous genetic, and probably environmental, factors. Indeed, several genes have been identified that together appear to cause most of the familial forms of the disease, whereas the epsilon4 allele of the apolipoprotein E (apoE) gene has been shown to be a significant risk factor for the late onset forms of AD. Despite this evidence of heterogeneity, it has been suggested that all of these factors work through a common pathway by triggering the deposition of amyloid in the brain, which is ultimately responsible for the neuronal degeneration of AD. This is a controversial theory, however, primarily because there is a poor correlation between the concentrations and distribution of amyloid depositions in the brain and several parameters of AD pathology, including degree of dementia, loss of synapses, loss of neurons and abnormalities of the cytoskeleton.
High-power, high-efficiency power amplifier reference design in III-V wide bandgap gallium nitride technology using nonlinear vector network analyzer and X-parameters

This paper presents a complete power amplifier design using new Nonlinear Vector Network Analyzer (NVNA) and X-parameter technologies. A high-power, pulsed Continuous Wave (CW) NVNA setup is presented and harmonic tuning capabilities of the measured X-parameter model is demonstrated using the same setup. From fundamental and harmonic impedance tuning, input and output power amplifier matching networks are synthesized and first-pass design success is confirmed by measurements of the fabricated power amplifier.
Can acetaminophen reduce the pain of decision-making?

Abstract Psychological and behavioral economic theories have shown that people often make irrational and suboptimal decisions. To describe certain decisions, people often use words related to pain (“hurt,” “painful”). Neuroscientific evidence suggests common overlap between systems involved in physical pain and decision-making. Yet no prior studies have explored whether a pharmacological intervention aimed at reducing physical pain could reduce the pain of decision-making. The current investigation filled this gap by assigning participants to consume the physical painkiller acetaminophen or placebo and then exposing them to situations known to produce cognitive dissonance (Experiment 1) or loss aversion (Experiment 2). Both experiments showed that acetaminophen reduced the pain of decision-making, as indicated by lower attitude change that accompanies cognitive dissonance and lower selling prices when selling personal possessions.
Olfaction and early detection of Parkinson's disease.

The article by Ponsen and colleagues and the accompanying editorial by Stern point out the importance of preclinical detection of risk for subsequent development of Parkinson’s disease. The interesting work by Ponsen and colleagues would suggest that tests of olfactory function, alone or in combination with other tests, may play a role in developing prognosticating tests. We developed such a test that, when applied prospectively to 212 subjects with symptoms suggestive but not diagnostic of Parkinson’s disease, was able to detect 40 of the 59 subjects subsequently diagnosed with Parkinson’s disease over a 2-year period. Also, the test battery, using tests of olfaction, motor speed, and depression, was able to predict 37 of 40 subjects in whom Parkinson’s disease subsequently was clinically excluded. The test battery was 92% specific and 68% sensitive with an area of the receiver operator characteristics curve of 0.88. Olfactory testing alone had a sensitivity of 82% and a specificity of 81%. Developing any diagnostic or prognostic test is complicated. In addition to specificity and sensitivity, prior probabilities (prevalence of those at risk) are a major factor. For example, the prevalence of persons at risk for Parkinson’s disease in a population of concern (such as first-degree relatives or those with specific environmental exposures) would have to be nearly 18% for olfactory testing to have a 50% positive and negative predictive value. Even at this, there would be as many false-positives and false-negatives as true-positives and true-negatives. Often little attention is given to the anticipated prevalence rates of those at risk when discussing potential diagnostic or predictive tests. Combining multiple tests into a diagnostic or prognostic battery to improve specificity and sensitivity is problematic. Ultimately, the choice of diagnostic or predictive test is social, that is, what are the social, economic, political, moral, and ethical consequences of failing to treat someone at risk versus treating someone not at risk. If an effective neuroprotective therapy is developed, who would be treated? What would happen if an effective neuroprotective treatment cost $10,000 per year and had to be taken continuously? Could or would our society be willing to pay such a cost? Could or would we say that only those who could afford neuroprotection are entitled to it? Perhaps it would be wise to devote efforts to resolve these questions at the same time we are developing neuroprotective therapies.
Cambrian paleosols and landscapes of South Australia

Cambrian marine, grey shales are widespread, and so are Cambrian intertidal, redbeds with weakly developed marine-influenced paleosols. A broader view of Cambrian landscapes and soilscapes now comes from paleosols of alluvial coastal plains of the Cambrian (to Ordovician?) Parachilna, Billy Creek, Moodlatana, Balcoracana, Pantapinna and Grindstone Range Formations in the central Flinders Ranges of South Australia. Paleosols are recognised by soil structures such as calcareous nodules (caliche) and cracked ridges (mukkara). They also show gradational changes down-profile in minerals, grainsize and chemical composition comparable with soils. Some of these Cambrian paleosols are thick (>1 m) and well developed (large caliche nodules). They indicate stable alluvial and coastal landscapes of quartzo-feldspathic and locally tuffaceous sediments. Paleoclimates were generally semiarid, although several intervals of subhumid paleoclimate coincide with local marine transgression. Drab-haloed filaments in red clayst...
Peripheral GABAA receptor-mediated effects of sodium valproate on dural plasma protein extravasation to substance P and trigeminal stimulation

1. The GABA transaminase inhibitor and activator of glutamic acid decarboxylase, valproic acid is being used for the treatment of migraine. Its mechanism of action is unknown. We tested the effects of sodium valproate and GABAA-agonist muscimol on dural plasma protein ([125I]-bovine serum albumin) extravasation evoked by either unilateral trigeminal ganglion stimulation (0.6 mA, 5 ms, 5 Hz, 5 min) or substance P (SP) administration (1 nmol kg-1,i.v.) in anaesthetized Sprague-Dawley rats. 2. Intraperitoneal (i.p.) injection of sodium valproate or muscimol, but not baclofen (< or = 10 mg kg-1, i.p.) dose-dependently reduced dural plasma protein extravasation caused either by electrical trigeminal stimulation (ED50: 6.6 +/- 1.4 mg kg-1, i.p., and 58 +/- 18 micrograms kg-1, i.p. for valproate or muscimol, respectively) or by intravenous substance P administration (ED50: 3.2 +/- 1.4 mg kg-1, i.p. and 385 +/- 190 micrograms kg-1, i.p. for valproate or muscimol, respectively). 3. Valproate (6.6 mg kg-1, i.p.) or muscimol (58 micrograms kg-1, i.p.) had no effect on mean arterial blood pressure or heart rate when measured for 30 min after i.p. administration. 4. The GABAA-antagonist bicuculline (0.01 mg kg-1, i.p.) completely reversed the effect of valproate and muscimol on plasma extravasation following electrical stimulation or substance P administration, whereas the GABAB-receptor antagonist, phaclofen (0.01-1 mg kg-1, i.p.) did not. Bicuculline or phaclofen, given alone, did not alter the plasma extravasation response after either electrical stimulation or SP administration. 5. Valproate decreased plasma extravasation following substance P administration in adult animals, neonatally treated with capsaicin by a bicuculline-reversible mechanism. This suggests that GABAA receptors are not found primarily on those afferent neurones or fibres which are sensitive to capsaicin treatment in neonatal rats.6. We conclude that sodium valproate blocks plasma extravasation in the meninges through GABAA mediated postjunctional receptors probably within the meninges. The dosages required are comparable to those used clinically. Agonists and modulators at the GABAA receptor may become useful for the development of selective therapeutic agents for migraine and cluster headache.