cssi/SciSciGPT-SciSciNet huggingface dataset:
Are Latin American Voters Campesinos o Empresarios? Economic Perceptions and Government Support 1995-2008

Very little is known about whether voters’ perceptions of the economy affect government support in the same way in developing countries as they do in developed ones. Indeed, weak party systems and a lack of democratic experience may work against prospective voting, high levels of poverty may force voters to emphasize pocketbook concerns at the expense of the national economy, and strong presidents and a lack of voter experience may reduce the role of the political and economic context in conditioning allocations of political credit and blame. Yet our two-stage hierarchical analysis of survey data from 18 Latin American countries over the 1995-2009 period shows that voters evaluate the incumbent prospectively at the beginning of the incumbent’s term and retrospectively at the end, emphasize sociotropic concerns more than egotropic ones except in the poorest countries, weight the economy more during periods of volatility than stability, and attribute responsibility for the economy according to the concentration of political control in the executive’s party. Thus voters in new democracies have the necessary conditions to hold politicians accountable for economic outcomes in the same way that voters in more established democracies do.
Modeling Humans as Reinforcement Learners: How to Predict Human Behavior in Multi-Stage Games

This paper introduces a novel framework for modeling interacting humans in a multi-stage game environment by combining concepts from game theory and reinforcement learning. The proposed model has the following desirable characteristics: (1) Bounded rational players, (2) strategic (i.e., players account for one anothers reward functions), and (3) is computationally feasible even on moderately large real-world systems. To do this we extend level-K reasoning to policy space to, for the first time, be able to handle multiple time steps. This allows us to decompose the problem into a series of smaller ones where we can apply standard reinforcement learning algorithms. We investigate these ideas in a cyber-battle scenario over a smart power grid and discuss the relationship between the behavior predicted by our model and what one might expect of real human defenders and attackers.
Independent navigation of multiple robots and virtual agents

We demonstrate an approach for collision- and oscillation-free navigation of multiple robots or virtual agents amongst each other. Each entity acts independently and uses only both the position and velocity of nearby entities to predict their future trajectories in order to avoid collisions. Entities take into account that the other entities are responding to them likewise to prevent oscillations.
Applications of Fungal Site-specific Recombination as a Tool in Biotechnology and Basic Biology

Two classes of conservative site-specific recombinases, those belonging to the tyrosine and serine families, have been identified, and several of its members characterized in genetic and biochemical detail. These families are named after the active site amino acid, tyrosine or serine, that is utilized as the nucleophile during the strand breaking step of recombination. The Flp recombinase encoded by the 2 micron plasmid of Sacchnromyces cerevisiae and related recombinases encoded by similar plasmids found in other yeast species belong to the tyrosine family. The Flp protein has provided several insights into the mechanism of target DNA recognition, strand cleavage and strand exchange during the recombination reaction. Here we describe how the Flp system has been used as a tool for tackling basic and applied problems in biology.
31P NMR and saturation transfer studies of the effect of Pb2+ on cultured osteoblastic bone cells.

The mechanism of lead toxicity at the cellular level remains unknown, although an effect of lead on intracellular Ca2+ has been described. Since bone is a major target for lead, we have investigated the effect of lead on bioenergetic rates and on the intracellular free Mg2+ concentration in cultured osteoblastic bone cells. Using 31P NMR and the saturation transfer technique we have detected a sizable (18%) transfer of saturation from gamma ATP to Pi in a perfused osteoblastic osteosarcoma bone cell line, Ros 17/2.8, and have found a large (greater than 82%) reduction in the Pi—-ATP rate upon treatment with 10 microM Pb2+. The NMR-measured unidirectional rate was much greater than the net rate of ATP synthesis through glycolysis and oxidative phosphorylation. By using iodoacetate we investigated the mechanism of the saturation transfer and found that it is catalyzed by the glycolytic enzyme couple glyceraldehyde-3-phosphate dehydrogenase/phosphoglycerate kinase. The net rate of glycolysis as measured by lactate production and that of oxidative phosphorylation as measured by O2 consumption were found to be significantly decreased by 18 and 74%, respectively, with lead treatment. In addition, from the chemical shifts of intracellular ATP resonances, we found a significant reduction of 21% in the intracellular free Mg2+ concentration upon Pb2+ treatment. The observed lead-induced reduction in ATP synthesis/utilization and the decrease in intracellular free Mg2+ may contribute to the impairment of bone formation during lead intoxication.
Tidal Potential with Location-Dependent Amplitude and Phase Angle

The tidal disturbing function has been developed in a form such that the Love number k and lag angle δ are expressed as a sum of spherical harmonics which are functions of latitude and longitude of the Earth. Solutions are made for the zonal harmonics to fit results obtained from artificial satellites. However, it does not appear that the time scale problem of the lunar orbit evolution can be solved without an appreciably smaller overall lag in the Earth in the past.
Now I Know Only So Far: Essays in Ethnopoetics

Now. Know Only So Far: Essays in Ethnopoetics. Dell Hymes. Lincoln: University of Nebraska Press, 2003. 512 pp.
Earthquake and ancient civilizations

The possible role of earthquakes in the destruction of ancient civilizations received an airing on December 13 at the 2001 AGU Fall Meeting in San Francisco, California. Amos Nur, professor of Earth sciences and geophysics at Stanford University, presented evidence that earthquakes and related tsunamis were responsible for leveling cities such as Megiddo, or Armageddon, and also have played a significant role in bringing down some ancient civilizations. Others presenting findings of earthquake destruction included Bernabe Garcia, a former graduate student at Stanford's Center for Latin American Studies, who assisted Stanford geophysics professor Robert Kovach in piecing together evidence of earthquakes in Meso-America that could have played a role in the collapse of the Mayan classic period in the ninth century. Manika Prasad, research associate in Stanford's Rock Physics Laboratory presented findings of his research with Nur that earthquakes may have contributed to the collapse of the Harappan civilization in South Asia around 1900 BC.
Magnetic Recording Heads

The sections in this article are 1 Basic Operation 2 Types of Recording Heads 3 Head Materials and Processing 4 Theory of Operation 5 Recording Head Testing 6 Future Directions
Normal Sleep Architecture

Normal sleep is a complex and critical physiological activity. It is characterized by discrete neurological patterns that represent different stages of sleep. To have restful sleep, each phase of sleep must be completed; otherwise, sleep disruption will result. Disruption of sleep architecture will result in excessive daytime somnolence and can lead to systemic disease.
Dialkylbiarylphosphine Complexes of Gold(I) Halides. Gold−Aryl π-Interactions in the Solid State

Dialkylbiarylphosphines are an emerging ligand set that promote catalytic reactions of electrophilic late transition-element centers through dative interactions of the biaryl arm with the metal site. Presented here are syntheses and crystal structures of five new (dicyclohexylbiarylphosphine)gold(I) chlorides and bromides. X-ray diffraction crystallography reveals close approaches between gold(I) and the flanking ipso carbon (mean Au−Cipso distance, compounds 2−6: 3.156 A). New compounds have been characterized by multinuclear NMR spectroscopy, X-ray diffraction crystallography, and combustion analysis.
In search of those boundary conditions that might influence the effectiveness of supportive supervision

Supportive supervision is doubtlessly beneficial in many instances in organizations. Paustian- Underdahl, Shanock, Rogelberg, Scott, Justice, and Altman () have examined the predictors of supportive supervision. We might suggest that they have underidentified those factors that impact the potential influence of supportive supervision and suggest a more comprehensive approach to this important variable. [ABSTRACT FROM AUTHOR]
Bedrock composition regulates mountain ecosystems and landscape evolution

Earth’s land surface teems with life. Although the distribution of ecosystems is largely explained by temperature and precipitation, vegetation can vary markedly with little variation in climate. Here we explore the role of bedrock in governing the distribution of forest cover across the Sierra Nevada Batholith, California. Our sites span a narrow range of elevations and thus a narrow range in climate. However, land cover varies from Giant Sequoia (Sequoiadendron giganteum), the largest trees on Earth, to vegetation-free swaths that are visible from space. Meanwhile, underlying bedrock spans nearly the entire compositional range of granitic bedrock in the western North American cordillera. We explored connections between lithology and vegetation using measurements of bedrock geochemistry and forest productivity. Tree-canopy cover, a proxy for forest productivity, varies by more than an order of magnitude across our sites, changing abruptly at mapped contacts between plutons and correlating with bedrock concentrations of major and minor elements, including the plant-essential nutrient phosphorus. Nutrient-poor areas that lack vegetation and soil are eroding more than two times slower on average than surrounding, more nutrient-rich, soil-mantled bedrock. This suggests that bedrock geochemistry can influence landscape evolution through an intrinsic limitation on primary productivity. Our results are consistent with widespread bottom-up lithologic control on the distribution and diversity of vegetation in mountainous terrain.
Effects of buspirone in the geller‐seifter conflict test with incremental shock

The novel anxiolytic buspirone has weak or inconsistent activity in most of the animal models commonly used to identify anxiolytics. Among the six published studies of the effects of buspirone on punished level-pressing in the rat, only one reported a clear effect (at two doses), and the peak effect was half that of diazepam. In the present study, in which rats responded for food in Geller-Seifter conflict procedure with incremental shock, five factors were examined for influence on the effects of buspirone upon punished lever-pressing: (1) fixed-ratio 10 vs. fixed ratio 1 in the punishment portion of the multiple schedule, (2) drug-naive vs. drug-experienced rats, (3) albino vs. hooded rats, (4) SC vs. PO injection, and (5) time course up to 2 hr. The benzodiazepine chlordiazepoxide robustly increased responding punished by foot-shock, but under none of the conditions did buspirone produce more than a small, inconsistent increase. Punished level-pressing in the rat appears not to be an adequate method for identifying buspirone-like anxiolytics.
In-situ phosphatizing coatings I: An air-dried lacquer system

The formulation of in-situ phosphatizing coatings (ISPCs) was successfully performed for lacquer systems using a commercial nitrocellulose lacquer and an optimum amount of in-situ phosphatizing reagents (ISPRs). The in-situ phosphatizing lacquer (ISPL) system is stable, and shows no change in surface appearance and drying speed as compared to the unmodified lacquer (UML). The ISPLs are applied on pine, poplar, and red oak wood boards, and on cold-rolled steel, aluminum, and laminated brass panels. Immersion tests in a 3% NaCl solution showed a remarkable enhancement in paint disbonding resistance for the paint film of ISPL on wood and metals compared to that of the UML sample. The paint film protective performance of ISPLs is further evidenced by the lattice pattern tape testings, and by the cathodic delamination and electrochemical impedance spectroscopy.
Partial oxidation of methane to formaldehyde by lithium promoted VPO catalysts

Abstract The effect of the addition of lithium cations to VPO phases on the catalytic activity of methane selective oxidation is reported. Two different methods of Li + addition were used: redox intercalation and co-precipitation. The redox intercalation procedure led to the most active promoted catalyst. XRD, FTIR, XPS characterization, oxygen isotopic exchange experiments and catalytic activity measurements using double-bed configuration were carried out. It is proposed that VPO activates methane forming of the intermediates which are further selectively oxidized by the Li + species and that the intercalation method allows the Li + to be well dispersed in the VPO surface and not covering completely the surface of the catalyst.
Intrapocket Anesthesia for Scaling and Root Planing: Results of a Double-Blind Multicenter Trial Using Lidocaine Prilocaine Dental Gel

Background: The efficacy of a novel anesthetic gel (lidocaine 25 mg/g plus prilocaine 25 mg/g in thermosetting agents) for non-invasive periodontal pocket anesthesia was evaluated. Methods: One hundred twenty-two (122) patients in 8 centers with moderate to severe periodontitis requiring scaling and root planing (SRP) were enrolled in this multicenter, randomized, double-blind, controlled clinical trial. The active dental gel or a matching placebo gel was applied into the periodontal pocket using a blunt applicator. Following a waiting period of 30 seconds to 2 minutes, scaling and root planing were performed. If the patient had any discomfort, a second application of the gel was applied. If the patient continued to experience discomfort, conventional anesthesia was offered. After all teeth in the test quadrant had received SRP, the overall pain was assessed by the patient using a 100 mm horizontal, ungraded visual analog scale in which the left side was marked "no pain" and the right side marked "worst p...
Dispositional and Explanatory Style Optimism as Potential Moderators of the Relationship between Hopelessness and Suicidal Ideation.

To test the hypothesis that higher levels of optimism reduce the association between hopelessness and suicidal ideation, 284 college students completed self-report measures of optimism and Beck scales for hopelessness, suicidal ideation, and depression. A statistically significant interaction between hopelessness and one measure of optimism was obtained, consistent with the hypothesis that optimism moderates the relationship between hopelessness and suicidal ideation. Hopelessness is not inevitably associated with suicidal ideation. Optimism may be an important moderator of the association. The development of treatments to enhance optimism may complement standard treatments to reduce suicidality that target depression and hopelessness.
The Neoproterozoic (1000–540 Ma) glacial intervals: No more snowball earth?

Abstract The Neoproterozoic interval (1000–540 Ma) contains ample evidence for a series of glacial intervals. These include the 750–700 Ma Sturtian glaciation, the 625–580 Ma Marinoan-Vendian glaciation and the 600–550 Ma Sinian glaciation. Paleomagnetic evidence has suggested that many of these glaciations occurred at tropical latitudes ( ⩽ 25°) and this led to a number of theories that attempt to explain the occurrence of these anomalously low latitude glaciations (e.g., an increase in the axial tilt of the earth, an equatorial low-orbit ice-ring, rapid equator to pole continental drift, incorrect identification of impact deposits as glacial deposits or secondary magnetizations misidentified as primary). New paleomagnetic data for Laurentia, China, Baltica and parts of Gondwana are combined with a reanalysis of previously published data to demonstrate that the Neoproterozoic glaciations may well all have occurred above 25° latitude. Climate models using a juvenile Sun of slightly lower luminosity, lower CO2 levels and coupling to Milankovitch cycles suggest that ice sheets could extend to within ±25° of the Neoproterozoic equator. Thus, the new paleomagnetic data and climate models offer an alternative explanation for the Neoproterozoic glaciations that is consistent with the waxing and waning of intermediate latitude ice sheets to form the conformable sequences of warm climate-cold climate strata.
Atmospheric waves observed in the planetary boundary layer using an acoustic sounder and a microbarograph array

Acoustic sounder and microbarograph records of atmospheric waves propagating in the planetary boundary layer over Table Mountain, Colorado, are presented and compared. The two observing techniques are complementary in that the array provides wave amplitude, horizontal phase speed, direction, and wavelength, while the sounder provides a detailed picture of temporal changes in the structure of the lowermost kilometer or so of the Earth's atmosphere.
TNF-α and H2O2 induce IL-18 and IL-18Rβ expression in cardiomyocytes via NF-κB activation

Abstract Myocardial ischemia/reperfusion is characterized by oxidative stress and induction of proinflammatory cytokines. Interleukin (IL)-18, a member of the IL-1 family, acts as a proinflammatory cytokine, and is induced during various immune and inflammatory disorders. Therefore, in the present study we investigated whether IL-18 expression is regulated by cytokines and oxidative stress in cardiomyocytes. TNF-α induced rapid and sustained activation of NF-κB whereas H 2 O 2 induced delayed and transient activation. Both TNF-α and H 2 O 2 induced IL-18 mRNA and precursor protein in cardiomyocytes, and IL-18 release into culture supernatants. However, only TNF-α led to sustained expression. Expression of IL-18Rβ, but not α, was induced by both agonists. TNF-α and H 2 O 2 induced delayed expression of IL-18 BP. Pretreatment with PDTC attenuated TNF-α and H 2 O 2 induced IL-18 and IL-18Rβ, but not basal expression of IL-18Rα. These results indicate that adult cardiomyocytes express IL-18 and its receptors, and proinflammatory cytokines and oxidative stress regulate their expression via activation of NF-κB. Presence of both ligand and receptors suggests IL-18 impacts myocardial biology through an autocrine pathway.
Chaotic and self-organized critical behavior of a generalized slider-block model

The dynamical behavior of two-dimensional arrays of slider blocks is considered. The blocks are pulled across a frictional surface by a constant-velocity driver; the blocks are connected to the driver and to each other by springs. Only one block is allowed to slip at a time and its displacement can be obtained analytically; the system is deterministic with no stochastic inputs. Studies of a pair of slider blocks show that they exibit periodic, limit-cycle, or choatic behavior depending upon parameter values and initial conditions. Studies of large, two-dimensional arrays of blocks show self-organized criticality. Positive Lyapunov exponents are found that depend upon the stiffness and size of the array.
Dietary and Hypothalamic Changes in Δ4-Androstenedione-Treated Zucker Rats

Dehydroepiandrosterone (DHEA) has been shown to alter hypothalamic monoamines and reduce energy intake (EI) in Zucker rats (ZRs). We hypothesized that a metabolite of DHEA, delta 4-Androstenedione (delta 4), may mediate these effects. Male lean and obese ZRs (LZR, OZR) were fed control chow (CC) for 7 days, during which basal EI was recorded, various concentrations of delta 4 for 7 days, during which 0.6 and 0.3% delta 4 reduced EI significantly, and CC for 7 days, which resulted in a return of EI to basal levels. After delta 4 administration, neurotransmitter contents of various hypothalamic areas were determined. Serotonin (5-HT) has been shown to be correlated with feeding inhibition, and we have shown DHEA to increase lateral hypothalamic 5-HT synthesis; however, after 1 day and 7 days of delta 4, the OZR exhibited an increased metabolism, not synthesis, of 5-HT in the lateral and paraventricular hypothalamus, respectively, delta 4 was compared to DHEA in a macronutrient self-selection study with female OZRs. One group was injected intraperitoneally (IP) with sesame oil (control), another with DHEA (100 mg/kg), and another with delta 4 (100 mg/kg). Previous studies have shown that DHEA decreases both EI and % calories from fat. In this study, delta 4 decreased % calories from fat, but did not decrease total EI. Contrary to DHEA's effect of reducing serum insulin through 28 days of treatment, delta 4 in chow reduced insulin only acutely (1 day). We conclude, based on these differences, that DHEA has unique effects not mediated by its metabolite, delta 4-Androstenedione.
Antibacterial membrane attack by a pore-forming intestinal C-type lectin

Human body-surface epithelia coexist in close association with complex bacterial communities and are protected by a variety of antibacterial proteins. C-type lectins of the RegIII family are bactericidal proteins that limit direct contact between bacteria and the intestinal epithelium and thus promote tolerance to the intestinal microbiota. RegIII lectins recognize their bacterial targets by binding peptidoglycan carbohydrate, but the mechanism by which they kill bacteria is unknown. Here we elucidate the mechanistic basis for RegIII bactericidal activity. We show that human RegIIIα (also known as HIP/PAP) binds membrane phospholipids and kills bacteria by forming a hexameric membrane-permeabilizing oligomeric pore. We derive a three-dimensional model of the RegIIIα pore by docking the RegIIIα crystal structure into a cryo-electron microscopic map of the pore complex, and show that the model accords with experimentally determined properties of the pore. Lipopolysaccharide inhibits RegIIIα pore-forming activity, explaining why RegIIIα is bactericidal for Gram-positive but not Gram-negative bacteria. Our findings identify C-type lectins as mediators of membrane attack in the mucosal immune system, and provide detailed insight into an antibacterial mechanism that promotes mutualism with the resident microbiota.
A Stable Mixed Disulfide between Thioredoxin Reductase and Its Substrate, Thioredoxin: Preparation and Characterization †

The flavoenzyme thioredoxin reductase (TrR) catalyzes the reduction of the small redox protein thioredoxin (Tr) by NADPH. It has been proposed that a large conformational change is required in catalysis by TrR in order to visualize a complete pathway for reduction of equivalents. The proposal is based on the comparison of the crystal structures of TrR and glutathione reductase, the latter being a well-understood member of this enzyme family (Waksman, G., et al. (1994) J. Mol. Biol. 236, 800- 816). Bound NADPH is perfectly positioned for electron transfer to the FAD in glutathione reductase, but in TrR, these two components are 17 A apart. In order to provide evidence for the proposed conformational change, a complex between TrR and its substrate Tr involving a mixed disulfide between TrR and Tr was prepared. The redox active disulfide of TrR is composed of Cys 135 and Cys 138 , and the redox active disulfide of Tr is made up of Cys 32 and Cys 35 . The complex C135S-C32S is prepared from forms of TrR and Tr altered by site-directed mutagenesis where Cys 138 and Cys 35 are remaining in TrR and Tr, respectively. The purified C135S-C32S presents a band on a nonreducing sodium dodecyl sulfate- polyacrylamide gel electrophoresis corresponding to a molecular weight sum of one subunit of TrR and one of Tr. Several observations indicate that C135S-C32S can adopt only one conformation. It was reported previously that TrR C135S can form a charge transfer complex in the presence of ammonium cation in which the donor is the remaining thiolate of Cys 138 (Prongay, A. J., et al., (1989) J. Biol. Chem. 264, 2656-2664), while titration of C135S-C32S with NH4Cl does not induce charge transfer, presumably because Cys 138 is participating in the mixed disulfide. Reduction of C135S-C32S with dithiothreitol (DTT) results in a decrease of454 to a value similar to that of TrR C135S, and subsequent NH4Cl titration leads to charge transfer complex formation in the nascent TrR C135S. Reductive titrations show that approximately 1 equiv of sodium dithionite or NADPH is required to fully reduce C135S-C32S, and treatment with NH4Cl and DTT demonstrates that the mixed disulfide remains intact. These results indicate that C135S-C32S is a stable mixed disulfide between Cys 138 of TrR C135S and Cys 35 of Tr C32S that locks the structure in a conformation where FAD can be reduced by NADPH, but electrons cannot flow from FADH2 to the mixed disulfide bond.
Effect of Mild Cognitive Impairment and APOE Genotype on Resting Cerebral Blood Flow and its Association with Cognition

Using whole-brain pulsed arterial spin labeling magnetic resonance imaging, resting cerebral blood flow (CBF) was measured in 20 mild cognitive impairment (MCI; 11 e3 and 9 e4) and 40 demographically matched cognitively normal (CN; 27 e3 and 13 e4) participants. An interaction of apolipoprotein (APOE) genotype (e3 and e4) and cognitive status (CN and MCI) on quantified gray-matter CBF corrected for partial volume effects was found in the left parahippocampal and fusiform gyri (PHG/FG), right middle frontal gyrus, and left medial frontal gyrus. In the PHG/FG, CBF was elevated for CN e4 carriers but decreased for MCI e4 carriers. The opposite pattern was seen in frontal regions: CBF was decreased for CN e4 carriers but increased for MCI e4 carriers. Cerebral blood flow in the PHG/FG was positively correlated with verbal memory for CN e4 adults (r=0.67, P=0.01). Cerebral blood flow in the left medial frontal gyrus was positively correlated with verbal memory for MCI e4 adults (r=0.70, P=0.05). Findings support dynamic pathophysiologic processes in the brain associated with Alzheimer's disease risk and indicate that cognitive status and APOE genotype have interactive effects on CBF. Correlations between CBF and verbal memory suggest a differential neurovascular compensatory response in posterior and anterior cortices with cognitive decline in e4 adults.
AMMONIA TREATMENT OF CARBON CLOTH ANODES TO ENHANCE POWER GENERATION OF MICROBIAL FUEL CELLS

Abstract Changes in microbial fuel cell (MFC) architecture, materials, and solution chemistry can be used to increase power generation by microbial fuel cells (MFCs). It is shown here that using a phosphate buffer to increase solution conductivity, and ammonia gas treatment of a carbon cloth anode substantially increased the surface charge of the electrode (from 0.38 to 3.99 meq m −2 ), and improved MFC performance. Power increased to 1640 mW m −2 (96 W m −3 ) using a phosphate buffer, and further to 1970 mW m −2 (115 W m −3 ) using an ammonia-treated electrode. The combined effects of these two treatments boosted power production by 48% compared to previous results using this air-cathode MFC. In addition, the start up time of an MFC was reduced by 50%.
Transplant coronary artery disease in children

Transplant coronary artery disease is an accelerated vasculopathy that occurs in adult and pediatric heart transplant recipients, and it is a leading cause of death among late survivors. This form of coronary disease, also known as graft coronary disease, differs from classical atherosclerosis in both histologic and angiographic features and it progresses much more rapidly. Although its pathogenesis has not been determined precisely, both immune and non-immune mechanisms appear to contribute, with a final common pathway of endothelial injury due to both antigen-dependent and antigen-independent factors. Many investigators believe both cellular and/or humoral rejection play a direct role in its etiology. In children the true incidence of the condition is unknown, although a multicenter survey identified 58 (7.2%) patients among 815 transplant recipients at 17 centers. Detection remains difficult. In the past, non-invasive methods have been unsatisfactory, although recent experience has suggested that Dobutamine stress echocardiography may be promising. Once a diagnosis is made, treatment has been limited to palliation by either intracoronary interventional procedures or surgical coronary bypass grafting, and to cardiac retransplantation with its own set of problems. Current efforts are directed at prevention. Blood levels of cholesterol have been reduced in adults treated with Pravastatin, but there have been no reports of its use in children. In adults additional agents with potential benefit have included calcium channel blockers and ACE inhibitors. A multicenter trial in children is needed to answer the many remaining questions regarding transplant coronary disease in this age group.
Influence of long-chain polyunsaturated fatty acids on oxidation of low density lipoprotein

Enrichment of low density lipoprotein (LDL) with long-chain fatty acids, such as eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (DHA; 22:6 n-3) found in fish oil, is thought to increase its oxidative susceptibility although such an increase has not been clearly demonstrated. The purpose of this study was to determine the composition and fatty acid concentration of LDL obtained from postmenopausal women given a supplement of fish oil and relate these values to its oxidative susceptibility. Fish oil supplementation significantly increased LDL concentration of EPA (P = 0.0001) and DHA (P = 0.0001) and decreased that of linoleic acid P = 0.006). The concentration of free cholesterol, cholesterol ester, phospholipids and protein was unchanged while triglyceride concentration increased 8% (P = 0.02). Cu2+-mediated oxidation resulted in a shorter lag time, slower oxidation rate and similar concentrations of conjugated dienes of EPA/DHA-enriched LDL than EPA/DHA-unenriched LDL. Stepwise multiple regression indicated that the primary predictor of oxidative susceptibility of LDL was linoleic acid, even after enrichment with EPA and DHA. The oxidation rate of EPA/DHA-unenriched LDL correlated with the cholesteryl ester concentration (P = 0.003) while that of EPA/DHA-enriched correlated with the concentration of phospholipids (P = 0.03). These data suggest that EPA/DHA-enriched LDL have decreased oxidative susceptibility and that surface lipids may mediate its rate of oxidation.
RENAL CELL CULTURE USING AUTOPSY MATERIAL FROM CHILDREN WITH CYSTINOSIS

Renal cell cultures were initiated using fresh autopsy material from two individuals with cystinosis, ages 5 and 8 yr. Cells obtained from collagenase treated autopsy material were grown in a selective kidney medium containing Coon's modified F12, 2.5% fetal bovine serum, transferrin, insulin, selenium, hydrocortisone, PGE1, and fibronectin. These cells had an epithelial appearance, formed domes, and were periodic acid-Schiff positive. Both tight junctions and microvilli were seen by electron microscopy. Fibroblasts had a cloning efficiency of zero in the selective medium and grew poorly compared to their growth in Coon's F12 with 10% fetal bovine serum. The lysosomal cystine content of the renal cells was greatly elevated and comparable to that of fibroblasts from cystinotic patients. Renal cell lysosomal cystine levels were only partially reduced by exposure to either pantethine or the aminothiol, cysteamine. However, exposure to either compound effectively depleted cystinotic cultured fibroblasts of their lysosomal cystine. Study of cultured renal material may have practical significance in pharmacologic considerations.
Shock-induced devolatilization of calcium sulfate and implications for K-T extinctions

The devolatilization of calcium sulfate, which is present in the target rock of the Chicxulub, Mexico impact structure, and dispersal in the stratosphere of the resultant sulfuric acid aerosol have been suggested as a possible mechanism for the Cretaceous-Tertiary extinctions. We measured the amount of SO_2 produced from two shock-induced devolatilization reactions of calcium sulfate up to 42 GPa in the laboratory: CaSO_4 + SiO_2 → CaSiO_3 + SO_3↑ CaSO_4 → CaO + SO_2↑ + 1/2O_2↑ We found both to proceed to a much lower extent than calculated by equilibrium thermodynamic calculations. Reaction products are found to be ∼ 10^(−2) times those calculated for equilibrium. Upon modeling the quantity of sulfur oxides degassed into the atmosphere from shock devolatilization of CaSO_4 in the Chicxulub lithographic section, the resulting 9 × 10^(16) to 6 × 10^(17) g (in sulfur mass) is lower by a factor of 10–100 than previous upper limit estimates, the related environmental stress arising from the resultant global cooling and fallout of acid rain is insufficient to explain the widespread K-T extinctions.
Alendronate/interleukin-1β cotreatment increases interleukin-6 in bone and UMR-106 cells: Dose dependence and relationship to the antiresorptive effect of alendronate

Aminobisphosphonates inhibit bone resorption but have been shown to elicit acute-phase-like elevations in interleukin-6 (IL-6) in bone in vitro. The current studies were carried out to determine the relationship between the antiresorptive effects of the aminobisphosphonate alendronate and its effects on IL-6. Resorption was elicited in cultured 19-day fetal rat limb bones by 72 h treatment with interleukin-1β (IL-1β). Bone mass was quantitated at the end of the culture period to assess resorption. IL-6 was determined by bioassay (7TD1 cell proliferation). IL-1β (18 and 180 pM) stimulated bone resorption and increased IL-6. Alendronate (70 μM) inhibited the IL-1β–stimulated resorption. Alendronate alone did not affect IL-6 production by the bones. The IL-6 production from bones stimulated with 18 pM IL-1β was not significantly affected by alendronate, but the IL-6 production from bones stimulated with 180 pM IL-1β plus alendronate (21 and 70 μM) was higher than with IL-1β alone. Indomethacin (1 mM) inhibited the IL-6 increase elicited by 180 pM IL-1β and the enhanced IL-6 production elicited by cotreatment with IL-1β and alendronate. Since bone cultures contain multiple cell types, further experiments were carried out to determine whether alendronate could increase IL-1β–stimulated IL-6 production in an osteoblast cell line, UMR-106. Alendronate alone did not affect IL6 in UMR-106 cells. Alendronate (70 μM) in combination with IL-1β (180, 1.8, or 8 nM), or 7 μM alendronate, in combination with 8 nM IL-1β, significantly increased IL-6 in 48 h cell cultures. The results from the bone organ cultures show that alendronate can enhance IL-6 production elicited by higher concentrations of the cytokine IL-1β in bone, but that this effect on IL-6 does not prevent the inhibitory actions of alendronate on bone resorption. The results with the UMR106 cells indicate that one cellular site at which this enhancement of IL-6 production can occur is the osteoblast.
Two-Dimensional Zymography Differentiates Gelatinase Isoforms in Stimulated Microglial Cells and in Brain Tissues of Acute Brain Injuries

Excessive activation of gelatinases (MMP-2/-9) is a key cause of detrimental outcomes in neurodegenerative diseases. A single-dimension zymography has been widely used to determine gelatinase expression and activity, but this method is inadequate in resolving complex enzyme isoforms, because gelatinase expression and activity could be modified at transcriptional and posttranslational levels. In this study, we investigated gelatinase isoforms under in vitro and in vivo conditions using two-dimensional (2D) gelatin zymography electrophoresis, a protocol allowing separation of proteins based on isoelectric points (pI) and molecular weights. We observed organomercuric chemical 4-aminophenylmercuric acetate-induced activation of MMP-2 isoforms with variant pI values in the conditioned medium of human fibrosarcoma HT1080 cells. Studies with murine BV-2 microglial cells indicated a series of proform MMP-9 spots separated by variant pI values due to stimulation with lipopolysaccharide (LPS). The MMP-9 pI values were shifted after treatment with alkaline phosphatase, suggesting presence of phosphorylated isoforms due to the proinflammatory stimulation. Similar MMP-9 isoforms with variant pI values in the same molecular weight were also found in mouse brains after ischemic and traumatic brain injuries. In contrast, there was no detectable pI differentiation of MMP-9 in the brains of chronic Zucker obese rats. These results demonstrated effective use of 2D zymography to separate modified MMP isoforms with variant pI values and to detect posttranslational modifications under different pathological conditions.
The deubiquitinating enzyme Ubp2 modulates Rsp5-dependent Lys63-linked polyubiquitin conjugates in Saccharomyces cerevisiae.

The functions of Lys63-linked polyubiquitin chains are poorly understood, as are the enzymes that specifically generate Lys63-linked conjugates. Rsp5 is a HECT (homologous to E6AP C terminus) ubiquitin ligase involved in numerous processes, and an associated deubiquitinating enzyme, Ubp2, modulates its activity. A dramatic increase in Lys63-linked conjugates was observed in ubp2Δ cells. The formation of these was Rsp5-dependent, and ubp2Δ phenotypes could be suppressed by prevention of formation of Lys63 conjugates. Cell wall integrity was impaired in rsp5-1 cells and in cells defective in Lys63-polyubiquitination, as assayed by calcofluor white sensitivity, and ubp2Δ and rup1Δ mutants suppressed the calcofluor white sensitivity of rsp5-1. A large fraction of the Lys63 conjugates in ubp2Δ cells bound to Rsp5, and a proteomics approach was used to identify Rsp5 substrates subject to Ubp2 regulation. Two closely related proteins, Csr2 and Ecm21, were among the identified proteins. Both were efficiently Lys63-polyubiquitinated by Rsp5 and deubiquitinated by Ubp2. Together, these results indicate that Ubp2 modulates Lys63-polyubiquitination of Rsp5 substrates in vivo, including ubiquitination of two newly identified Rsp5 substrates.
Quantifying seasonal precipitation using high-resolution carbon isotope analyses in evergreen wood

High-resolution natural abundance stable carbon isotope analyses across annual growth rings in evergreen trees reveal a cyclic increase and decrease in the measured carbon isotopic composition (d 13 C), but the causes of this pattern are poorly understood. We compiled new and published high-resolution d 13 C data from across annual growth rings of 33 modern evergreen trees from 10 genera and 15 globally distributed sites to quantify the parameters that affect the observed d 13 C pattern. Across a broad range of latitude, temperature, and precipitation regimes, we found that the average, measured seasonal change in d 13 C( Dd 13 Cmeas, &) within tree rings of evergreen species reflects changes in the carbon isotopic composition of atmospheric carbon dioxide (Dd 13 CCO2) and changes in seasonal precipitation (DP) according to the following equation: Dd 13 Cmeas = Dd 13 CCO2 – 0.82(DP) + 0.73; R 2 = 0.96. Seasonal changes in temperature, pCO2, and light levels were not found to significantly affect Dd 13 Cmeas. We propose that this relationship can be used to quantify seasonal patterns in paleoprecipitation from intra-ring profiles of d 13 C measured from non-permineralized, fossil wood.
Las visiones de Petrarca en la poesía hispánica y en la poética renacentista

In Spain as in Spanish America in the Golden Age, imitatio held sway as the dominant poetics. Yet the concept of imitatio is an elastic one. How can a twenty-first century reader grasp the meaning of Renaissance imitatio ? As a means of addressing this question, this essay analyzes the relationship of important poems to their source text, foregrounding Bartolomeo Ricci’s concepts of sequi , imitare , and aemulare , presented in the 1541 De imitatione. Focusing on the rich legacies of Canzone 323 ( delle Visioni) by Francesco Petrarca in the poetry of (among others) Diego Davalos y Figueroa, Francisco de Quevedo, Lope de Vega, Fray Luis de Leon and Juan de Guevara, the essay provides a powerful explication of the generative properties of imitatio . [This article published in the author's original Spanish.]
Kinetics of Energy Flow in the Phycobilisome Core

Light energy absorbed by the 576 bilin chromophores in the six rods of the phycobilisome of the cyanobacterium Synechocystis 6701 is funneled into a 1.5 x 106 dalton core. The 72 bilins of the core function as a single unit with respect to the rate-limiting processes for energy flow within these particles.
More than search? Informational and participatory eHealth behaviors

Few studies in the eHealth literature have paid attention to participatory eHealth behaviors. Addressing this gap, the present study examines how informational and participatory eHealth behaviors are related to eHealth literacy, Internet use and Facebook interaction, as well as user characteristics. Drawing on a sample of college students (N=540), results from Structural Equation Modeling (SEM) analysis show that eHealth literacy has a positive direct effect on informational eHealth behaviors. It also serves as a mediator suppressing the negative relationship between excellent mental health status and eHealth behaviors. While both instrumental Internet use and Facebook interaction are related to participatory eHealth behaviors, only instrumental Internet use is associated with informational eHealth behaviors. There are significant eHealth disparities by health status, gender, and class. Implications for health communication and promotion are discussed.
Doppler echocardiographic-guided diagnosis and therapy of heart failure

Abnormalities of diastolic function play a major role in producing the signs and symptoms of heart failure. In patients with heart failure and reduced left ventricular systolic function, concomitant diastolic dysfunction is invariably present. In addition, it is now well established that as many as 40% to 50% of patients with well-documented episodes of heart failure have preserved systolic function. Doppler echocardiography provides one of the most useful clinical tools for assessing left ventricular diastolic function and can provide diagnostic and prognostic information. The Doppler assessment of diastolic function should be part of the routine echocardiographic evaluation of patients suspected of having heart failure. This review focuses on the use of Doppler echocardiographic techniques to assess diastolic function. The Doppler patterns of diastolic filling observed and their progression over time in patients with myocardial disease are described and related to changes in the physiology of diastolic filling. In addition, Doppler echocardiographic-guided treatment strategies for heart failure are discussed.
Respiration and the Energy Requirement for Nitrogen Fixation in Nodulated Pea Roots

Pisum sativum L. cv. Trapper plants were inoculated and grown in a controlled environment on N-free nutrient solution. After 4 weeks N was supplied to treatment plants as NH4NO3, KNO3, or NH4Cl and rates of C2H2 reduction, root + nodule respiration, and leaf photosynthesis were determined 1 week later. The increase in respiration per unit of C2H2 reduction was not affected by either the form of N added or the light conditions during growth, although the basal respiration rate with no C2H2 reduction increased with irradiance level. The mean regression coefficient from plots of respiration versus C2H2 reduction was 0.23 + 0.04 (P [unk] .01) mg of CO2 (μmol of C2H2 reduced)−1 which was very similar to the value for the coefficient of respiration associated with nitrogenase activity estimated by subtracting growth and maintenance respiration. Since the rate of N accumulation in N-free nutrient conditions was proportional to the rate of C2H2 reduction, it appears that the method gives a true estimate of the energy requirements for N fixation which for these conditions was equivalent to 17 grams of carbohydrate consumed per gram of N fixed.
A Case of Aspirin Exacerbated Respiratory Disease (AERD) with Aspirin-Induced Hypersensitivity Vasculitis

S U N D A Y 393 Drug Hypersensitivity Reactions in Patients with Clonal Mast Cells Disorders Carla Lombardo, Patrizia Bonadonna, MD, CME, Roberta Zanotti, Gianenrico Senna, MD, Giovanni Passalacqua, MD; Allergy Unit, Azienda ospedale Universit a di Verona, Italy, Allergy Unit of Azienda Ospedaliera Universitaria Integrata Allergy Unit, Verona, Italy, Department of Clinical and Experimental Medicine, Haematology Section, University of Verona, Italy, Allergy Unit, Verona, Italy, University of Genoa, Genoa, Italy. RATIONALE: The occurrence and characteristics of drug-induced anaphylaxis in patients with clonal mast cell disorders (CMD) is largely unknown. In this single-center study we assessed the prevalence of drug hypersensitivity in a population of mastocytosis patients. METHODS: All patients with ascertained CMD, followed in our clinic were asked to fill a questionnaire about previous adverse drug reactions. Patients with drug hypersensitivity underwent to oral challenge tests (OCT) with alternatives drug. RESULTS: 158 patients were enrolled; 89 (56.3%) male, mean age 52614 years. In 58.9% of patients the diagnosis of CMD was done after hymenoptera sting anaphylaxis, and in 7% after drug anaphylaxis. Fiftyone (32.3%) patients reported a total number of 78 drug hypersensitivity reactions, 16 (31.4%) had 2 or more episodes and 7 (13.7%) with different drug classes. The most frequently involved drugs were NSAIDs (54.9% of patients, 43 episodes), and antibiotics (41.2% of patients, 25 episodes). Anaphylaxis occurred in 11/28 (39%) patients with NSAIDs reactions and in 10/21 (47.6%) patients with antibiotics, mostly amoxicillin (66.7%). Thirty-eight OCTwith alternative NSAIDs (13 nimesulide, 14 etoricoxib, 6 meloxicam, 3 paracetamol and 2 aspirin) were performed and only 1 patient had rhinitis during aspirin challenge. Thirty-seven OCTs with antibiotics (15 clarithromycin, 13 ciprofloxacin, 2 clindamycin, 2 doxyciclin, 2 amoxicillin and 3 cefuroxime) were performed without adverse reactions. CONCLUSIONS: In our population the prevalence of self reported drug hypersensitivity was 32.3%, that is higher than in general population. The most involved drugs are antibiotics and NSAIDs. OCT with alternative drugs are safe and useful tools for a diagnosis.
Mechanisms of Action of Anticonvulsant Drugs

Summary: Understanding the mechanisms of action of anticonvulsant drugs has been a major research effort of neuroscientists for the last three decades. Numerous biochemical and electrophysiological processes have been shown to be modulated by anticonvulsant drugs. However, clear correlations of these effects with anticonvulsant activity are often difficult to determine. Over the last 5 years, several major research areas have developed that shed new light on the mechanisms of action of anticonvulsant drugs. Although a complete discussion of all aspects of anticonvulsant research are, not possible in the scope of this article, a description of benzodiazepine receptors, mechanisms involved in neuronal sustaining repetitive firing, and calcium regulation of neuronal function have direct bearing on neuronal excitability and ultimately on anticonvulsant drug effect. Each of these major research areas has opened new insights into our understanding of molecular mechanisms of how anticonvulsant drugs work.