cssi/SciSciGPT-SciSciNet huggingface dataset:
Two types of MeV ion beam enhanced adhesion for Au films in SiO2

The ion beam-enhanced adhesion of thin Au films on vitreous silica substrates was studied for a wide range of Cl ion beam doses for beam energies between 6.5 MeV and 21.0 MeV. Since the residual adhesion of Au on SiO_2 is low, the improved adhesion can be easily seen using the Scotch Tape Test. The threshold in the enhanced adhesion corresponding to passing the tape test occurs at two different dose ranges for a given energy; one at very low dose centered around 1 × 10^(13) /cm^2, the other at higher doses with a threshold of around 1.5 × 10^(14) /cm^2 (depending upon the beam energy). At low doses (2 × 10^(12) to 5 × 10^(13) /cm^2) surface cracks occur on the SiO_2 substrates, these cracks close up at doses higher than 5 × 10^(13) /cm^2. A possible explanation of enhanced adhesion in the low dose range is associated with the surface crazing of the SiO_2 substrate. To make the adhesion test more quantitative, a scratch test was also used on the samples.
Ecphory of autobiographical memories: An fMRI study of recent and remote memory retrieval

Ecphory occurs when one recollects a past event cued by a trigger, such as a picture, odor, or name. It is a central component of autobiographical memory, which allows us to “travel mentally back in time” and re-experience specific events from our personal past. Using fMRI and focusing on the role of medial temporal lobe (MTL) structures, we investigated the brain bases of autobiographical memory and whether they change with the age of memories. Importantly, we used an ecphory task in which the remote character of the memories was ensured. The results showed that a large bilateral network supports autobiographical memory: temporal lobe, temporo-occipito-parietal junction, dorsal prefrontal cortex, medial frontal cortex, retrosplenial cortex and surrounding areas, and MTL structures. This network, including MTL structures, changed little with the age of the memories.
Evidence for increased monoculture cropping in the Central United States

Abstract While crop rotation patterns can be complex with multiple crops rotated over several years, the most common rotation practice in the Central United States is biannual rotation between corn and soybeans. We analyzed the changes in crop rotation patterns from 2003 to 2010 using the Cropland Data Layer (CDL), which provides remotely sensed land cover layers for agricultural crops in the Central United States. The accuracy of the CDL was validated by comparing the total acreage for a state or county present in the CDL with the total planted crop acreage available from the National Agricultural Statistics Service. The data layers were combined into two time periods 2003–2006 and 2007–2010, and specific rotation patterns were determined for every location in the study area. The combinations resulted in unique sequences such as single, double, triple and quadruple, the latter of which is equivalent to the same crop class present all four years at a particular location. Corn and soybeans were analyzed to determine the amount of area used for production as well as the amount of change between unique crop rotation sequences. While the total area under production of major crops in the second half of our study period increased only slightly, the extent to which major crops (e.g., corn and soybeans) were grown in continuous cropping sequences increased significantly. For example, the amount of land impacted by corn in the first time period increased by only 2% in the second time period. However, the amount of corn grown in quadruple sequence doubled from the first half to the second half of our study period. We conclude that, although crop rotation patterns are very complex in this region, involving considerable amount of non-cropland, the footprint of major crops such as corn have moved toward monoculture cropping practices in the last decade.
SU-E-CAMPUS-T-01: Automation of the Winston-Lutz Test for Stereotactic Radiosurgery

Purpose: To optimize clinical efficiency and shorten patient wait time by minimizing the time and effort required to perform the Winston-Lutz test before stereotactic radiosurgery (SRS) through automation of the delivery, analysis, and documentation of results. Methods: The radiation fields of the Winston-Lutz (WL) test were created in a “machine-QA patient” saved in ARIA for use before SRS cases. Images of the BRW target ball placed at mechanical isocenter are captured with the portal imager for each of four, 2cm×2cm, MLC-shaped beams. When the WL plan is delivered and closed, this event is detected by in-house software called EventNet which automates subsequent processes with the aid of the ARIA web services. Images are automatically retrieved from the ARIA database and analyzed to determine the offset of the target ball from radiation isocenter. The results are posted to a website and a composite summary image of the results is pushed back into ImageBrowser for review and authenticated documentation. Results: The total time to perform the test was reduced from 20-25 minutes to less than 4 minutes. The results were found to be more accurate and consistent than the previous method which used radiochromic film. The images were also analyzed with DoseLabmore » for comparison. The difference between the film and automated WL results in the X and Y direction and the radius were (−0.17 +/− 0.28) mm, (0.21 +/− 0.20) mm and (−0.14 +/− 0.27) mm, respectively. The difference between the DoseLab and automated WL results were (−0.05 +/− 0.06) mm, (−0.01 +/− 0.02) mm and (0.01 +/− 0.07) mm, respectively. Conclusions: This process reduced patient wait times by 15–20 minutes making the treatment machine available to treat another patient. Accuracy and consistency of results were improved over the previous method and were comparable to other commercial solutions. Access to the ARIA web services is made possible through an Eclipse co-development agreement with Varian Medical Systems.« less
Anti-Ro fine specificity defined by multiple antigenic peptides identifies components of tertiary epitopes.

Anti-Ro (or SSA) is a clinically important autoantibody that is found in 25–40% of patients with systemic lupus erythematosus as well as an even greater proportion of patients with Sjogren's syndrome or subacute cutaneous lupus. We have studied the binding of anti-Ro sera to multiple antigenic peptides constructed from the sequence of the 60-kD Ro molecule. The results demonstrate that sera bind these peptides in solid-phase assay. Surprisingly, some of these peptides also form a precipitin line in double immunodiffusion with anti-Ro sera. Formation of lines of identity in double immunodiffusion as well as absorption studies indicate that peptides distant in the primary amino acid sequence and without shared sequence are bound by the same antibody. In addition, data from surface plasmon resonance demonstrate that peptides identified in this manner have protein–protein interactions. Thus, these techniques may identify the components of conformational epitopes.
Current Alzheimer's disease clinical trials: Methods and placebo outcomes

Abstract Background Eighteen-month-long randomized, placebo-controlled clinical trials are common for phase II and phase III drug development for Alzheimer's disease (AD). Yet, no 18-month trial has shown statistically significant outcomes favoring the test drug. We examined characteristics and underlying assumptions of these trials by assessing the placebo groups. Methods We searched the clinicaltrials.gov registry for randomized, placebo-controlled clinical trials for AD of at least 18-month duration and extracted demographic, clinical, and trials characteristics, and change in main outcomes from the placebo groups. We obtained additional information from presentations, abstracts, publications, and sponsors. Results Of 23 trials identified, 11 were completed and had baseline data available; nine had follow-up data available; 17 were phase III. General inclusion criteria were very similar except that minimum Mini-Mental State Examination (MMSE) scores varied from 12 to 20. Sample sizes ranged from 402 to 1,684 for phase III trials and 80 to 400 for phase II. Cholinesterase inhibitor use was from 53% to 100%, and memantine use was from 13.5% to 78%. The AD Assessment Scale-cognitive (ADAS-cog) was the co-primary outcome in all trials; and activities of daily living, global severity, or global change ratings were the other co-primaries. APOE ɛ4 genotype carriers ranged from 58% to 67%; mean baseline ADAS-cog was 17.8 to 24.2. ADAS-cog worsening in the placebo groups during 18 months ranged from 4.34 to 9.10, with standard deviations from 8.17 to 9.39, increasing during 18 months. Conclusions Inclusion criteria are essentially similar to earlier 6-month and 12-month trials in which cholinesterase inhibitors were not allowed, as were mean ADAS-cog rates of change. Yet increasing variability and relatively little change overall in the ADAS-cog placebo groups, eg, about 25% of patients do not worsen by more than 1 point, might make it more unlikely than previously assumed that a modestly effective drug can be reliably recognized, especially when the drug might work only to attenuate decline in function and not to improve function. These observations would be strengthened by pooling individual trials data, and pharmaceutical sponsors should participate in such efforts.
Small-angle neutron scattering study of a thermally aged, segmented poly(ester urethane) binder

Abstract Small-angle neutron scattering (SANS) measurements have been performed on a thermally aged polymeric binder to understand the effects of aging on its microstructure. The binder is a 50%–50% (by weight) mixture of a segmented poly(ester urethane), known as EstaneB 5703, and a nitro-plasticizer (NP). This compound is of interest because it is used in the high-explosive (HE) PBX9501. The addition of the polymeric binder to the crystalline HE imparts both structural integrity and plasticity to the HE, allowing it to be readily machined and pressed to specific densities. In addition, the binder significantly affects the performance and the sensitivity of the HE, due in part to its influence on the propagation of microstresses between crystalline grains under shock or loading conditions. So changes in the binder over time can influence the behavior of the HE system as a whole.
Frequency Response of Theoretical Models of Junction Transistors

SMALL-SIGNAL parameters are very useful for determining the electric-circuit performance of a transistor. However, for a junction transistor these parameters are not independent of frequency as is now fairly well known. One type of frequency variation in the parameters occurs because of the feedback mechanism and the effect of collector capacity as described by J. M. Early.1 A second type of frequency variation occurs because of the diffusion process by which junction transistors operate. Frequency variations of parameters due to the diffusion process for the ideal one-dimensional model introduced by Shockley have been calculated independently by the writer,2 by J. M. Early3 and by H. O. Johnson.4 Addition of a constant base-spreading resistance to the base lead of the one-dimensional model completes the over-all theoretical model commonly used. In practice, this model applies fairly well to alloy, or fused junction, transistors.6 On the other hand, for grown-junction transistors, the distributed nature of the transistor parameters in the transverse direction of the base region must be taken into account. Analysis of such a two-dimensional model6 has shown that under simplifying conditions such a transistor may be represented by the usual one-dimensional ideal model plus a complex frequency-dependent base impedance in series with the base lead. Hence, the grown-junction transistor can be represented by the same type of model as that used for the fused-junction transistor, but with the constant base-spreading resistance of the latter model replaced by a more general complex base impedance. In practice, this two-dimensional model applies fairly well to grown-junction transistors having a base connection that approximates a line contact. For grown-junction transistors in which the base connection is not a line type of contact, the base impedance may be partly resistive and partly complex.
Pb isotope variations in hydrogenetic Fe–Mn crusts from the Izu–Bonin fore-arc

Abstract Fe–Mn crusts were recovered from the western escarpment of the Bonin Ridge in the Izu–Bonin fore-arc region (dive site #824: 28.612°N, 141.803°E) at water depths of c. 2900 m using the Shinkai 6500 submersible during cruise YK 04–05. Major and trace element data and XRD mineralogy indicate that the crusts are hydrogenetic in origin. We present profiles of variations in Pb isotope composition measured in-situ by laser ablation MC-ICP-MS across two of the crusts. The isotopic variations are systematic and can be matched up between the two crusts, indicating similar growth rates. The crust Pb isotope composition rules out any local source for Pb from within the Izu–Bonin–Mariana arc system, either from hydrothermal activity or through leaching of volcanic detritus. Input of a globally well-mixed volcanic Pb component, either from aerosols or as an absorbed component on aeolian dust, has been proposed as a mechanism to explain the Pb isotope composition of Central Pacific deep water. However, the Izu–Bonin crusts are displaced to lower 206Pb/204Pb and higher 208Pb/204Pb, which requires an additional Pb source. One possibility is that as water is advected from the south, outboard of the Luzon–Ryukyu–Honshu arc system, it is progressively polluted by Pb derived by weathering and erosion of these young island arc volcanic systems. Using a constant Co-flux model, growth rates are estimated at ∼ 7–13 mm/Ma, which would suggest that these crusts provide a record of changes in the composition of deep water in the Izu–Bonin fore-arc region of the western Pacific Ocean over the last 4–8 Ma. Over this interval, the main feature has been a progressive decrease in 207Pb/206Pb (0.843 to 0.839) and 208Pb/206Pb (2.088 to 2.080) with time. The interior parts have compositions similar to those of crusts from the Izu–Bonin fore-arc, while the rims have compositions similar to crusts from the central Western Pacific.
Gold metal-catalyzed reactions of isocyanides with primary amines and oxygen: analogies with reactions of isocyanides in transition metal complexes.

Despite its generally poor catalytic properties, bulk gold metal is observed to catalyze reactions of isocyanides (C⋮N−R) with primary amines (H2N−R‘) and O2 to give carbodiimides (R−NCN−R‘) at room temperature and above. Detailed infrared reflection absorption spectroscopic (IRRAS) and kinetic studies show that the reaction occurs by initial η1-adsorption of the isocyanide on the Au surface, which activates the isocyanide to attack by the amine. This attack is the rate-determining step in the catalytic cycle and has characteristics very similar to those of amine reactions with coordinated isocyanides in transition metal complexes. However, the metallic Au surface provides a pathway involving O2 to give the carbodiimide product whereas homogeneous metal ion catalysts give formamidines [HC(NR)(NHR‘)].
Evaluation of Nitrate Content of Ground Water in Hall County, Nebraskaa

Nitrate concentrations in ground water are low, less than 10 mg/l, in most parts of Hall County. Water from 46 percent of the sampled wells had nitrate concentrations greater than 10 mg/l, and 13 percent had greater than 45 mg/l. Sharp contrasts in concentrations occurring within short distances are common. Seasonal changes and a progressive increase of nitrate concentrations have occurred in some observed wells. Concentrations decrease with increasing well depth and well penetration below the water table. Nitrate in ground water is stratified where the concentration is high. Highest concentrations are found at or near the water table in the vicinity of sampled wells located close to a potential nitrate source. Potential sources of nitrate in the ground water of Hall County are fertilizers, feedlots, septic-tank effluents, seepage from the Wood River, precipitation, and soil fertility. Whereas seepage from the Wood River contributes nitrate to ground water adjacent to the stream, seepage from the Platte River dilutes the nitrate content of ground water. The hydraulic conductivity of the unsaturated zone is an important factor in controlling nitrate content of ground water.
Experimental consequences and constraints for magninos

Abstract A stable weakly interacting massive particle can simultaneously solve both the solar neutrino and missing mass problems. In a previous paper we have identified this particle with a neutral lepton with mass of order 4–10 GeV and an anomalous magnetic moment of order 10 −2 (in natural units). We call this new particle a “magnino”. In one scenario, the magnino is the neutral component of an electroweak doublet. Its charged partner must have a mass only a few GeV heavier. In this paper we discuss the experimental consequences of the magnino, its charged partner and associated Higgs.
Myth: All surfactants are alike

There are several surfactant preparations available to the clinician, none of which are alike. They differ in their phospholipid and surfactant protein (SP) composition as well as dosing, yet they all have been shown to be clinically effective as surfactants. Head-to-head randomized clinical trials comparing surfactants have shown some advantages of preparations that contain SP-B and SP-C, primarily in short-term clinical outcomes. A new synthetic surfactant that contains a phospholipid mixture and a peptide resembling SP-B has shown promise as a potential alternative to animal-derived surfactants.
Simulating Tolerance in Dynamic Social Networks

This paper studies the concept of tolerance in dynamic social networks where agents are able to make and break connections with neighbors to improve their payoffs. This problem was initially introduced to the authors by observing resistance or tolerance in experiments run in dynamic networks under the two rules that they have developed: the Highest Rewarding Neighborhood rule and the Highest Weighted Reward rule. These rules help agents evaluate their neighbors and decide whether to break a connection or not. They introduce the idea of tolerance in dynamic networks by allowing an agent to maintain a relationship with a bad neighbor for some time. In this research, the authors investigate and define the phenomenon of tolerance in dynamic social networks, particularly with the two rules. The paper defines a mathematical model to predict an agent's tolerance of a bad neighbor and determine the factors that affect it. After defining a general version of tolerance, the idea of optimal tolerance is explored, providing situations in which tolerance can be used as a tool to affect network efficiency and network structure.
Radical Relocation: Adapting Print Collections to an E-Centric World

With the advent of e-journal preservation projects and publisher digitization of journal backfiles, academic libraries have begun to move their corresponding print volumes of these titles to storage to avoid duplication and save space. This article examines the supporting justifications, outreach mechanisms, and logistical procedures undertaken at American University Library to relocate the entire bound journal collection to offsite storage in order to address severe physical space constraints and to support patron use of and preference for electronic journal content. In addition, the article presents preliminary data regarding the use of bound volumes sent to storage and an overall analysis of this transformational project.
Structure and assembly of haptoglobin polymers by electron microscopy.

Haptoglobin (Hp) consists of light (L) and heavy (H) chains, the latter of which combine with hemoglobin alpha beta dimers to form a highly stable complex. Human haptoglobin assembles as HL units that occur in two allelic forms; HL1 , which is monovalent, and HL2 , which is divalent. As a result, three phenotypic forms exist in the human population: Hp1-1, the homozygous form in which the monovalent HL1 unit occurs as a dimer; Hp2-2, the homozygous form of the divalent HL2 unit, which gives a series of polymers; and the heterozygous Hp2-1 form, which gives a different series of polymers. We have investigated the structures and assembly properties of these two haptoglobin polymeric series in their complexes with hemoglobin using high-resolution scanning transmission electron microscopy. Polymers of complex are composed of ellipsoidal or bilobal head groups, which are the H alpha beta subunits connected by thin filament-like structures, which are the L chains. Polymers of size up to pentamers can be identified easily by counting the number of head groups in the molecule. Complex 2-1 and complex 2-2 trimers were studied extensively. The differences in detailed morphology show that while the 2-1 trimer is a linear polymer, the 2-2 trimer is a closed circular molecule. The micrograph images suggest that complex 2-2 tetramers and pentamers, and perhaps higher forms may also be cyclic. The structure of the L2 subunit of haptoglobin is shown to be composed of two domains, which may be similar in structure to the single domain of the monovalent L1 chain. The two L2 domains are connected by a hinge that has quite limited flexibility. Using these structural models, assembly characteristics and structural properties of the trimers and tetramers of complex 2-1 and complex 2-2 are described.
A Bidirectional Graphical Model for Babble-feedback Learning in Speech☆

Abstract A theory of motor-feedback learning based on a bidirectional-edge graph is summarized. The graph is inspired as a model of the cortico-thalamic circuit. Output from the network drives the motors of an articulatory speech synthesizer. The network is first exposed to an ongoing stream of speech sounds where neural fields tune themselves to respond to repetitive co-occurring patterns in the input (phonetic features). The network is then made to actuate motors with babble feedback learning in an effort to train the network to produce the speech sounds and strings of sounds that the network was originally exposed to. The model furthermore makes use of a bank of resonators, intended to depict the functional role of the cerebellum. This cerebellar model helps in coordinating the longer-term timing of network dynamics and helps to smoothly string together patterns of speech sounds through time.
Discussion of "Gumbel — Hougaard Copula for Trivariate Rainfall Frequency Analysis"

Consideration of the multivariate nature of hydro-meteorological processes associated with hydrologic systems is important when assessing the availability of water resources and the risks caused by extreme events and when conducting rainfall-runoff simulation and modeling. Detailed statistical analysis of rainfall, as one of the main factors affecting water availability and extreme conditions, is required for estimating the design parameters. Storm depth, duration, inter-arrival duration, and areal spread are among the main features of rainfall process. One or more of these factors need to be analyzed depending on the type of hydrological application at hand. However, this is further complicated by the fact that a wide range of areal coverage and thereby durations of rainfall are usually of interest Linsley and Franzini 1979, p. 122. Intensity-duration-frequency curves are aimed at the requirements of obtaining extreme rainfall values for different durations and aid design of small to medium-sized drainage systems. Analysis of storm depth and duration, or intensity and duration, along with the inter-arrival duration, on the other hand, is required for applications such as deriving flood frequency distributions from climatic characteristics Eagleson 1972 and simulating rainfall events for the purpose of modeling rainfall-runoff, assessing water availability, and drought studies, among other activities. The application of Gumbel-Hougaard copula for trivariate rainfall frequency analysis in the paper involves the three rainfall variables storm depth, duration, and mean intensity of the annual largest rainfall events. The largest annual rainfall event is identified as the storm having the highest rainfall depth. The mean intensity is obtained as the ratio of the corresponding storm depth and duration. Any pair of two of these three variables constitute a bivariate data set as the joint occurrence of the constituents is random in nature. However, considering all three variables simultaneously makes this a nonsubstantive trivariate case as any one of the variables could be computed from the knowledge of the other two. In other words, as the third variable is algebraically determinable and does not have any randomness in its occurrence when the other two are given, a bivariate frequency analysis may suffice. This one-to-one relationship of mean intensity with depth and duration, as given by Eq. 18b in Zhang and Singh 2006 ,i s illustrated in the perspective plot in Fig. 1a. As in the paper, the annual largest storms at Liberty rainfall station for the period of 1980 to 2006 have been considered in this illustration. A minimum of six hours of dry period between storms is employed as the criteria to define the storms. This helps combine rain spells that are separated by less than six hours into single storms, as such intermittent spells are typically part of the same storm. This is also the criteria employed by the authors to identify the individual storms. It is seen, as expected, that all the observed data points fall exactly on the surface given by
Simple routes for improving polythiophene:fullerene-based organic solar cells

Abstract Improved power conversion efficiency (PCE), by up to ∼27%, of organic solar cells based on poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS)/poly(3-hexylthiophene):[6,6]-phenyl-C 60 -butyric acid methyl ester (P3HT:PCBM) were obtained via simple modifications, widely applicable, in the fabrication of the spin-coated PEDOT:PSS layer. These included (i) further diluting the original PEDOT:PSS solution with deionized water, (ii) mixing the original PEDOT:PSS solution with ethylene glycol (EG), and (iii) spin coating EG over a PEDOT:PSS layer fabricated using the original solution. The optimal dilutions, spin coating rates, and durations were determined. Approach (iii) resulted in the best cell with a PCE of 4.7% as compared to 3.7% for the untreated PEDOT:PSS. To evaluate the origin of the improvements we monitored the PEDOT:PSS conductivity, external quantum efficiency of the devices, and their I–V curves that indicated an increase of ∼16% in the short-circuit current I SC . Other characteristics included the PEDOT:PSS layer thickness, its transmittance, P3HT:PCBM absorption spectra, its morphology, and surface chemical composition. The results indicate that in addition to the enhanced PEDOT:PSS conductivity (following some of the treatments) that improves charge extraction, enhanced PEDOT:PSS transmission and especially, enhanced P3HT:PCBM absorption contribute to improved solar cell performance, the latter by increasing I SC . While the various treatments in the optimized devices had a minor effect on the PEDOT:PSS thickness, its morphology, and consequently that of the active layer, were affected. The surface roughness of the active layer increased significantly and, importantly, in devices with PEDOT:PSS/EG/P3HT:PCBM, PCBM aggregates were observed near the cathode. Such aggregates may also result in increased absorption and improved charge extraction.
Mechanism of attenuated hydrochlorothiazide response during indomethacin administration

Indomethacin antagonizes the natriuretic and chloruretic response to hydrochlorothiazide in most studies. Neither the mechanism nor nephron site of this antagonism has been determined. To identify sites and potential mechanisms, cortical micropuncture was performed during hydrochlorothiazide treatment in control and indomethacin rats. Indomethacin reduced (P less than 0.005) FeCl from 5.20 +/- 0.49% to 2.26 +/- 0.49% (mean +/- SE). MAP, CIn, and plasma volume were not different between groups. SNGFR and fractional proximal fluid and chloride delivery were not different between groups. Fractional chloride delivery to early distal tubules was 10.8 +/- 0.4% in control but 6.2 +/- 0.3% in indomethacin rats (P less than 0.001). Calculated loop chloride reabsorption was greater in indomethacin than control rats during hydrochlorothiazide administration (41.0 +/- 1.6% vs. 34.3 +/- 2.3%; P less than 0.05). Fractional chloride delivery to late distal tubules was 7.8 +/- 0.7% in control and 4.6 +/- 0.3% in indomethacin rats (P less than 0.005), but distal tubule chloride reabsorption was not different between groups. Papillary tissue chloride was less in control than indomethacin rats during hydrochlorothiazide (P less than 0.05). Urinary PGE2 excretion was reduced (P less than 0.001) by indomethacin during hydrochlorothiazide. Thus indomethacin induced reductions in hydrochlorothiazide response result in part from increased chloride reabsorption in the loop segment. This suggests indomethacin antagonizes hydrochlorothiazide by reducing chloride delivery to hydrochlorothiazide's site of action in the distal tubule rather than by effects of indomethacin on hydrochlorothiazide pharmacokinetics.
Review and Application of Prestressed Shell Theories to Blood Vessel Wave Propagation

In many situations involving the dynamic behavior of blood vessels it is essential to account for the significant prestresses to which the vessels are subjected. Also, it is clearly established that the constitutive law of any tissue is very complex, e.g., Fung. In addition, King and Lawton, Anliker et al., Anliker et al. have demonstrated that the elastic response of the vessel to the natural cardiac pulse can be significantly nonlinear. However, for a number of investigations such as those devoted to determination of the wall material properties, we are primarily concerned with the behavior of the vessel as it responds in a small neighborhood of a quasi-static prestessed state. In the experiments the wall material properties are deduced by measuring the amplitude and phase differences for mechanically induced high-frequency waves propagating down the vessel, as described in Ref. 3, for example. For such cases the pertijrbatipn strains of interest are small and it is reasonable, at least as | first approximation, to treat the vessel wall material as perfectly elastic and consider the prestressed state as given. In reviewing the well-known literature on prestressed shells, e.g., Refs. 5-10, it is immediately obvious, as in many other fields of shell analysis, that the equations used by the various authors dp not agree in all respects. It is appropriate to study whether such differences have any significant influence on the phase velocities in simplified models of veins'and arteries. Another subject of considerable interest is the fact that unlike metal structures, the inplane strains induced by the prestress in the primary arteries are not small compared to unity.
Restoration of potassium-stimulated respiration of ‘glycerol-treated’ muscle

Abstract Agents that produced contracture in skeletal muscle, such as caffeine or K-depolarization, also caused an increased rate of oxygen consumption. Both of these functions are calcium dependent. In this study the respiratory response to K-depolarization and to caffeine was monitored in lgycerol-treated and normal frog sartorius muscles. Although glycerol-treated muscle does not contract in response to K-depolarization, it does develope normal caffeine contractures. The respiratory response to both potassium and caffeine is greatly inhibited in glycerol-treated muscles. Pretreatment with dibutyryl cyclic AMP restored the respiratory response to normal levels in glycerol-treated muscle. Pretreatment with low levels of caffeine and resulted in a normal respiratory response to K-depolarization even though there was no tension development. Caffeine had no effect on adnyl cyclase activity even at concentrations that markedly stimulated oxygen uptake. The data suggest that potassium stimulation of oxygen uptake in glycerol-treated muscle is uncoupled by a defect in the formation of a cyclic nucleotid cofactor, rather than a defect in clacium influx.
Using marine natural products to discover a protease that catalyzes peptide macrocyclization of diverse substrates.

Small N−C terminally cyclic ribosomal peptides are common in nature, yet the mechanisms underlying their biosyntheses remain largely unknown. We recently identified candidate peptide cyclase genes in the metagenomes of marine animals. Here we report that PatG, a protease discovered in this analysis, cleaves variables, short peptides out of a precursor protein, and cyclizes these peptides in vivo and in vitro.
Invasive exotic plant indicators for ecosystem restoration: An example from the Everglades restoration program

We have developed a comprehensive ecological indicator for invasive exotic plants, a human-influenced component of the Everglades that could threaten the success of the restoration initiative. Following development of a conceptual ecological model for invasive exotic species, presented as a companion paper in this special issue, we developed criteria to evaluate existing invasive exotic monitoring programs for use in developing invasive exotic performance measures. We then used data from the selected monitoring programs to define specific performance measures, using species presence and abundance as the basis of the indicator for invasive exotic plants. We then developed a series of questions used to evaluate region and/or individual species status with respect to invasion. Finally, we used an expert panel who had answered the questions for invasive exotic plants in the Everglades Lake Okeechobee model to develop a stoplight restoration report card to communicate invasive exotic plant status. The report card system provides a way to effectively evaluate and present indicator data to managers, policy makers, and the public using a uniform format among indicators. Collectively, the model, monitoring assessment, performance measures, and report card enable us to evaluate how invasive plants are impacting the restoration program and how effectively that impact is being managed. Applied through time, our approach also allows us to follow the progress of management actions to control the spread and reduce the impacts of invasive species and can be easily applied and adapted to other large-scale ecosystem projects.
Controlled generation of black carbon particles from a diffusion flame and applications in evaluating black carbon measurement methods

Abstract Measurements of black carbon (BC) concentration have long been uncertain. Neither a BC standard or a technique that provides a reliable measurement of BC exist, which precludes the evaluation and optimization of BC measurement methods. In this manuscript, we describe the generation of BC particles (mass absorption efficiency ∼8.5 m2 g−1 and single scattering albedo ∼0.2 at 530 nm) using an inverted diffusion flame. This flame is remarkably stable and can be used to generate a wide range of nearly constant concentrations of BC particles for many (e.g., 10+) hours. The particles contain essentially no organic carbon (OC), so the quantification of BC mass using any of the thermal or thermal–optical analysis (TOA) methods is straightforward instead of highly uncertain. In this case, the TOA measurement of BC can be used to evaluate the accuracy of other BC measurement methods. In this paper, we demonstrate the application of the diffusion flame in evaluating BC measurements made with filter-based light transmission methods, and in particular the aethalometer. We show that the amount of light attenuated by a BC-laden filter increases in less than constant proportion to the BC mass loading, and thus the effective BC attenuation coefficient decreases with increased BC mass loading. When sampling BC at constant concentration, the aethalometer erroneously reports decreasing concentrations of BC as its filter becomes increasingly loaded because it treats the attenuation coefficient as a constant. A simple method to correct erroneous aethalometer data when sampling aerosols with low single scattering albedo is presented. Another application of the diffusion flame considered in this paper is the development of BC standards for TOA. We envision the preparation of filter samples with known amounts of BC mixed with other aerosol constituents, which may help in understanding the uncertainty in and optimizing TOA measurements, and may be of use in future TOA method comparison studies. Toward this end, we demonstrate that the diffusion flame can be used to replicate filter samples with known amounts of BC. Additionally, we show that the combustion temperature of BC during TOA depends on sample composition, which suggests that the temperature-defined carbon fractions of some thermal and TOA methods may be of limited value.
A dual pathway model of daily stressor effects on rheumatoid arthritis

This study evaluated the initial promise of a dual-pathway conceptual model linking daily event stressors to rheumatoid arthritis (RA) disease activity through changes in immune system activation and mood. Fifty individuals, who were studied on five occasions two weeks apart, reported daily event stressors on the Daily Life Experience Checklist, daily mood on an abbreviated version of the Profile of Mood States-B, and daily joint pain on the Rapid Assessment of Disease Activity in Rheumatology. Serial clinical examinations comprised ratings of joint tenderness and swelling, and blood drawn during exams was analyzed for sedimentation rate (an indicator of systemic inflammation) and soluble interleukin-2 receptors (a marker of immune system activation known to correlate with RA disease activity). Across-person analyses failed to establish links from daily event stressors to either disease activity or composites of joint pain and joint inflammation when associations were adjusted for the effect of neuroticism on self-report measures. Pooled within-person analyses, however, were generally consistent with the relations predicted by the dual-pathway model. Increases in daily event stressors during the week preceding each clinical exam were associated with increased joint pain (regardless of changes in mood). At the same time, increased daily stressors were indirectly associated with decreased joint inflammation through reduction in levels of soluble interleukin-2 receptors. The dual-pathway model, which may be limited to short-term psychological and psychoimmunologic processes, underscores the importance of distinguishing potentially opposing effects of stress on pain versus inflammation in individuals with rheumatoid arthritis.
HIGHER-ORDER-MAGNETIZATION-CUMULANT UNIVERSALITY OF THE TWO-DIMENSIONAL ISING MODEL

We study the higher-order cumulant universality of the order-parameter distribution at criticality for the two-dimensional nearest-neighbor ferromagnetic Ising model with Monte Carlo methods. These cumulants are interesting because they are a quantitative measure of the shape of the critical order parameter distribution. This shape has been predicted to be universal. Up to now, only the fourth-order cumulant has been studied in any detail. The set of higher-order cumulants as a whole is more sensitive to the details of the distribution and hence is a stronger test. It cannot be sampled efficiently with standard Monte Carlo sampling. To the best of our knowledge, no definite numerical results have been reported in the literature. Using the umbrella-sampling technique, we are able to obtain accurate estimates for the fourth-, sixth-, eighth-, and tenth-order cumulants for both the square and triangular lattices of different lattice sizes. These results support universality.
Coordinated power management of voltage islands in CMPs

Multiple clock domain architectures have recently been proposed to alleviate the power problem in CMPs by having different frequency/voltage values assigned to each domain based on workload requirements. However, accurate allocation of power to these voltage/frequency islands based on time varying workload characteristics as well as controlling the power consumption at the provisioned power level is non-trivial. Toward this end, we propose a two-tier feedback-based control theoretic solution. Our first-tier consists of a global power manager that allocates power targets to individual islands based on the workload dynamics. The power consumptions of these islands are in turn controlled by a second-tier, consisting of local controllers that regulate island power using dynamic voltage and frequency scaling in response to workload requirements.
Post-feeding bubbling behaviour in fluid-feeding Diptera: concentration of crop contents by oral evaporation of excess water.

During long post-feeding periods, adult tephritid flies (and apparently other non-blood feeding Diptera and even Hymenoptera) engage in behaviour consisting of oral extrusion and aeration of liquid droplets of varying size (‘bubbling’), proboscis pumping, and occasional deposition of regurgitate on the substrate that is followed by subsequent re-ingestion. Unlike evaporative cooling, which occurs in some insects when heat-stressed, these regurgitation behaviours take place regularly at moderate temperatures. To our knowledge, the significance of these behaviours has not been studied. We suggest that through bubbling behaviour, fully gorged Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) flies eliminate excess water by evaporation to concentrate nutrients suspended in dilute solution, and release crop volume to allow resumption of fluid feeding or minimize the water load while foraging for other resources. Fly weights were measured continuously during pre- and post-feeding periods and in relation to occurrence of regurgitation behaviours. Fly weight losses during pre-feeding were an order of magnitude lower than post-feeding weight losses when flies exposed regurgitated liquid crop contents to air. During a bout of droplet extrusions, lasting on average 23 min, weight loss averaged 66% of the weight of liquid ingested by a fly in the preceding meal. Fly weight loss while bubbling was significantly correlated with duration of bubbling, temperature and relative humidity during post-feeding, and initial fly weight (adj. R2 = 0.95). Fly age, volume of liquid ingested and rate of pre-feeding weight loss did not significantly improve predicted weight loss through bubbling. Findings are discussed in relation to other behaviours adopted by fluid-feeding insects to eliminate excess water.
The Yucca Mountain Standard: Proposals for Leniency

The proposed geologic repository at Yucca Mountain, Nevada, for spent nuclear fuel and other highly radioactive waste needs an official standard to protect the public from release of radioactivity. Standards proposed by the U. S. Congress, the nuclear industry (NEI), the Electric Power Research Institute (EPRI), the Department of Energy (DOE), and the TYMS Committee of the National Research Council (NRC) are reviewed. Each of these proposals would introduce a degree of leniency not heretofore experienced in radiation protection. No adequate scientific justification is presented. Some scientifically invalid proposals are said to be justified on the grounds of policy. Most leading industrial nations are designing geologic repositories to meet the traditional criteria for safety and for protecting public health, including quantitative calculations of doses for the periods when significant doses can occur, rather than stopping calculations at 10,000 years as many in the U. S. would have us do. There is no evidence that they are seriously seeking more lenient standards for public health protection. The U. S. has the resources and skills to protect future people from our waste with the same care that we now protect the public from radiation. We should assert our will to do so. The Yucca Mountain project will be seriously damaged if it is directed to depart from the traditional conservative criteria for determining safety and protection of public health, criteria that are adopted in other countries working on geologic disposal.
Phillips Receives 2008 Whipple Award

Roger J. Phillips received the Whipple Award at the 2008 AGU Fall Meeting Honors Ceremony, held 17 December in San Francisco, Calif. The award recognizes an individual who has made an outstanding contribution in the field of planetary science.
Seizure prediction through dynamic synchronization measures of neural populations

Recent studies have focused on the phenomena of abnormal electrical brain activity which may transition into a debilitating seizure state through the entrainment of large populations of neurons. Starting from the initial epileptogenisis of a small population of abnormally firing neurons, to the mobilization of mesoscopic neuron populations behaving in a synchronous manner, a prediction methodology has been formulated that compares the initial epileptogenisis to distant neuron populations. As two neuron populations begin to operate in a synchronized manner, the respective signals phase lock, manifesting into a seizure state. The normal non-linear dynamic signal captured through an EEG enters a semi-periodic state, which can be quantified into a seizure state. A method for capturing synchronous behavior of the pathological brain state is described. An individual patient based phase-locking threshold is introduced for seizure prediction and for differentiating seizure and non-seizure states.
Walking and running in the red-legged running frog, Kassina maculata

SUMMARY Although most frog species are specialized for jumping or swimming, Kassina maculata (red-legged running frog) primarily uses a third type of locomotion during which the hindlimbs alternate. In the present study, we examined Kassina 9s distinct locomotory mode to determine whether these frogs walk or run and how their gait may change with speed. We used multiple methods to distinguish between terrestrial gaits: the existence or absence of an aerial phase, duty factor, relative footfall patterns and the mechanics of the animal9s center of mass (COM). To measure kinematic and kinetic variables, we recorded digital video as the animals moved over a miniature force platform ( N =12 individuals). With respect to footfall patterns, the frogs used a single gait and walked at all speeds examined. Duty factor always exceeded 0.59. Based on COM mechanics, however, the frogs used both walking and running gaits. At slower speeds, the fluctuations in the horizontal kinetic energy ( E k ) and gravitational potential energy ( E p ) of the COM were largely out of phase, indicating a vaulting or walking gait. In most of the trials, Kassina used a combined gait at intermediate speeds, unlike cursorial animals with distinct gait transitions. This combined gait, much like a mammalian gallop, exhibited the mechanics of both vaulting and bouncing gaits. At faster speeds, the E k and E p of Kassina 9s COM were more in phase, indicating the use of a bouncing or running gait. Depending on the definition used to distinguish between walking and running, Kassina either only used a walking gait at all speeds or used a walking gait at slower speeds but then switched to a running gait as speed increased.
A uvby database for Stephenson-Sanduleak southern luminous stars

A database of published Stromgren four-color uvby photoelectric photometry for objects in the Stephenson-Sanduleak Luminous Stars in the Southern Milky Way catalog has been compiled from the literature. Of 5132 stars in the catalog, 817 have uvby colors and magnitudes available; altogether, the database incorporates 1181 observations from 41 references. The database is available electronically at CDS, and lists LS number, HD or CD number, , m 1 , c 1 , number of observations, numeric codes for notes and references, galactic and b coordinates, and aliases for named or variable stars.