cssi/SciSciGPT-SciSciNet huggingface dataset:
Modeling secondary organic aerosol using a dynamic partitioning approach incorporating particle aqueous-phase chemistry

Abstract Current air quality model (AQM) systems use either an Odum-type two-product or a volatility basis set (VBS) approach to predict secondary organic aerosol (SOA) formation from toluene oxidation. For the SOA module in AQM systems, the stoichiometric and partitioning coefficients used in both these approaches are typically developed from laboratory studies conducted in a single chamber, under a limited set of conditions (e.g., low humidity and initial (NH 4 ) 2 SO 4 seed), and with an implicit assumption of instantaneous thermodynamic equilibrium. In this study, we evaluated independent toluene laboratory studies that include experiments with different combinations of initial toluene, NO x , non-SOA-forming hydrocarbon mixture, initial seed type, and humidity. When evaluated against this observational data set both the Odum-type and VBS approaches fail to predict observed SOA when tested under dry conditions, in the presence of the hydrocarbon mixture, and with low initial seed mass, regardless of seed type. For wet experiments, predictions of temporal trends in aerosol mass growth from both approaches are inconsistent with observations; this is especially true earlier in the day under high humidity conditions. Based on these findings, a new SOA mechanism is developed that includes: 1) gas-phase reaction of semi-volatile products and a dynamic partitioning approach with accommodation coefficient as the principal transport parameter, 2) an additional pathway of SOA formation due to uptake of polar species into the particle aqueous-phase. The new mechanism improves predicted SOA mass reproducing observations from all experiments. Since these changes were made exclusively to existing algorithms in SOA modules, minimal modifications would be required to update air quality models to utilize this approach.
Electrical space conditioning in the USA

'Electrical space conditioning' expresses the need to consider control of all factors influenced by modern building lighting. When the criteria of good lighting design are established, attention can be turned to controlling and using the heat generated by lighting. Examples show that modern lighting installations introduce sufficient energy to largely counterbalance building energy losses in cold weather. In warm weather the energy introduced from the lighting, together with heat gains from people, machines and sun, must be controlled. Returning air through luminaires not only brings thermal gains under control but does much to offset radiant heating effects. Typical installations using electrical space conditioning principles are analysed and the range of systems that can be usad is indicated.
THE EFFECTS OF SCHEDULE HISTORY AND THE OPPORTUNITY FOR ADJUNCTIVE RESPONDING ON BEHAVIOR DURING A FIXED-INTERVAL SCHEDULE OF REINFORCEMENT

The effects of schedule history and the availability of an adjunctive response (polydipsia) on fixed-interval schedule performance were investigated. Two rats first pressed levers under a schedule of food reinforcement with an interresponse time greater than 11 s, and 2 others responded under a fixed-ratio 40 schedule. All 4 were then exposed to a fixed-interval 15-s schedule. Water was continuously available under these conditions, but after responding became stable on the fixed-interval schedule, access was experimentally manipulated. With water freely available, subjects did not display characteristic fixed-interval response rates and patterns (i.e., scalloping or break-and-run). Instead, they exhibited predictable, stable patterns of behavior as a function of their schedule histories: Subjects with the interresponse-time history exhibited low response rates, and those with the fixed-ratio history exhibited high rates. Manipulating the amount of water available resulted in marked changes in response rates for rats with the interresponse-time history but not for those with the fixed-ratio history. The results illustrate the multiple causation of behavior by its previous and current schedules of reinforcement and other concurrent factors.
Claims and Credibility: A Discussion of Occupational Identity and the Agent-Client Relationship

In the course of trying to establish or maintain their occupational identities, American helping groups often forward claims which their clients disbelieve or which rival helping groups try to discredit. The history of helping groups reflects their ideological and institutional responses to this dilemma, through attempts to change helping claims, occupational structure, client attitudes, or clientele. The problem of credibility influences both technological and organizational aspects in the developing identities of helping occupations.
Spectral signatures for the classification of microbial species using Raman spectra

In general, classification-based methods based on confocal Raman microscopy are focused on targeted studies under which the spectral libraries are collected under controlled instrument parameters, which facilitate analyses via standard multivariate data analysis methods and cross-validation. We develop and compare approaches to transform spectra collected at different spectral ranges and varying levels of resolution into a single lower-dimension spectral signature library. This will result in a more robust analysis method able to accommodate spectra accumulated at different times and conditions. We demonstrate these approaches on a relevant test case; the identification of microbial species from a natural environment. The training data were based on samples prepared for three unique species collected at two time points and the test data consisted of blinded unknowns prepared and analyzed at a later date with different instrument parameters. The results indicate that using reduced dimension representations of the spectral signatures improves classification accuracy over basic alignment protocols. In particular, utilizing the microbial species partial least squares discriminant analysis classifier on the blinded samples based on alignment achieved ~78 % accuracy, while both binning and peak selection approaches yielded 100 % accuracy.
Molecular charge mapping with electrostatic force microscope

Abstract We are attempting charge mapping & potentiometry on biological and molecular systems using a modifiedAtomic Force Microscope(AFM) — ElectrostaticForce Microscope(EFM). With an interferometric detection system,we have obtained potentiometric sensitivity better than 0.1 mV and spatial resolution of about 200A. The images of red blood cells in air clearly show surface potential variation, independent of topography. We imaged FEP ((poly)tetrafluoroethylene -co- hexafluoropropylene) films lithographically patterned with APS (poly(aminopropyl)siloxane). We have been able to positively identify the modified regions (APS) from the unmodified regions (FEP) using charge information. The charge density we estimated on the unmodified FEP regions of oursamples is about 109C/cm2. 1. Introduction The Atomic Force Microscope(AFM) has demonstrated the capability of visualizing atoms and molecules with a spatial resolution down to the atomic scale." By moving the tip several nanometers away from the sample, long rangeattractive forces, such as electrostatic forces, can be detected.3 The charge mapping capability is significant becausealmost all interfaces are electrified, many molecules residing on the interfaces are non-uniformly charged, and theircharge density determines, to a large extent, their chemical and biological characteristics. Presently there are no otherknown techniques capable of directly measuring the electrostatic charge density on molecules with nanometer scaleresolution.
Aortic enzymes and lactate in high altitude-raised and cholesterol-fed rabbits

Fourteen male rabbits born at elevation 4000 ft (first experimental series) were transferred at age of 2 months to elevation 12470 ft and raised there for 18 weeks. Half of the animals remained on a commercial rabbit chow (group H) while the other half was on the same diet supplemented with cholesterol (group C). Eight male rabbits raised at sea level served as controls (group S). Intima-media homogenates from the thoracic aortas were assayed for lactate dehydrogenase (LDH), malate dehydrogenase (MDH), lipoamide dehydrogenase, pyruvate kinase (PK), phosphofructokinase (PFK) and the lysosomal hydrolases beta-glucuronidase and N-acetyl-beta-glucosaminidase (NAGA). Aortic lactate and glucose were also measured. Thirty-two male rabbits (second experimental series) were subdivided into 4 groups. Rabbits were fed a cholesterol-supplemented diet not only at high altitude (8 rabbits matching group C) but also 8 animals raised at sea level. The degree of atherosclerosis in the aortas of these 4 groups was assessed by measuring the aortic cholesterol contents. Plasma cholesterol was also determined. In the aortas of the rabbits of group H the activity of PK was significantly elevated, and the activity of the lysosomal hydrolases significantly decreased compared with aortas of group S rabbits. There was no difference in the other enzyme activities or in the aortic glucose and lactate content of these groups. Cholesterol feeding of the animals of group C resulted in a significantly increased activity of the lysosomal hydrolases as well as of LDH and PK. The lipid analyses (second experimental series) revealed a trend to a lower concentration of aortic cholesterol in the high altitude than in the sea level animals, both fed a cholesterol diet, in spite of the higher plasma cholesterol concentrations in the high altitude animals. The low aortic lysosomal hydrolase activities in the high altitude rabbits are in accord with their comparatively lower susceptibility to experimental atherosclerosis. This metabolic feature may be due to a lower degree of exposure of these aortas to injurious factors, such as infections or lower blood pressure. The elevated activity of PK without increased lactate content in group H animals seems to parallel the well-known general adaptation of the organism to high altitude hypoxia, and does not indicate a metabolic switch toward anaerobic glycolysis.
Possible seismogenic shallow-dipping normal faults in the Woodlark-D'Entrecasteaux extensional province, Papua New Guinea

Active normal faults dipping less than 30° have not been documented in the seismic record, but they are commonly observed in geologic structures. One interpretation is that seismogenic low-angle faulting is physically impossible and that the geologic structures do not form at shallow dips. To better examine this problem, teleseismic body waves were inverted to determine source parameters for five large earthquakes in the Woodlark-D9Entrecasteaux region, a rare example of active continental extension associated with Pliocene-Quaternary metamorphic core complexes. The inversions show that at least two and possibly four events are consistent with normal dip slip on shallow-dipping faults. The largest earthquake (M w = 6.8) is located near the mapped core complexes. The shallow-dipping plane for this event, determined to dip between 10° and 25°, is nearly coplanar to the faults bounding the core complexes and may represent slip on these or other parallel low-angle structures. Although slip on the conjugate high-angle plane cannot be ruled out, observations of Quaternary uplift and the similarity to the adjacent core-complex-bounding structures favor motion on the low-angle plane. Similar earthquake mechanisms have not yet been documented in most other extensional provinces, perhaps because instances of active core-complex exhumation are rare.
Ciliary beat frequency of hamster oviducts is decreased in vitro by exposure to solutions of mainstream and sidestream cigarette smoke.

Epidemiological data support a correlation between smoking and increased incidence of ectopic pregnancy, yet the causal mechanism responsible for this relationship is unknown. The purpose of this study was to examine the effect of solutions containing dissolved mainstream (MS) or sidestream (SS) cigarette smoke on ciliary beat frequencies (CBF) in explants of hamster oviducts. MS smoke is the puff inhaled by an active smoker, while SS smoke leaves the burning end of cigarette. SS smoke is inhaled by both active and passive smokers. Experimentswere performed in handmade perfusion chambers using infundibula from hamster oviducts. After a short incubation in Earle's balanced salt solution containing HEPES buffer (EBSS-H), chambers were flushed with one of six types of smoke solution prepared in EBSS-H, and incubation continued 19 min. A second perfusion (washout) was then done using EBSS-H alone to determine whether effects induced by the smoke solutions could be reversed. CBF were determined at three times in both the smoke and washout solutions, and means were compared to values obtained in the initial EBSS-H incubation. All smoke solutions except the SS particulate solution inhibited CBF in a dose-dependent manner. Whole MS and whole SS smoke solution at the highest strength tested caused the greatest inhibition and in some cases completely stopped ciliary beating. Both single-strength and 0.1-strength MS gas phase solutions, which contained concentrations of nicotine in the range found in typical human smokers, produced about 50% inhibition of ciliary beating. Inhibition was generally seen within 2-12 min of adding smoke solutions. In all cases, washout of smoke solution caused an increase in CBF. In some washouts, CBF returned to initial values found in EBSS-H within 2 min of incubation in the recovery medium. However, in both MS and SS whole smoke solutions, CBF did not return to the initial EBSS-H values during the washout interval. In SS gas phase solutions, inhibition was not observed during exposure to the smoke solution but did occur during washout, suggesting that the mechanism of action of SS gas phase solutions differs from the other types of smoke solution tested. These results show that components in both MS and SS cigarette smoke can inhibit beating of oviductal cilia in vitro and that inhibition can be at least partially reversed when the smoke solution is replaced by EBSS-H.
The role of secretion and pressure-dependent flow in aqueous humor formation

Abstract The role of the capillary filtration pressure and secretory activity in determining the rate of net inward movement of solute and water across the ciliary processes is examined theoretically using previously published experimental data. The theoretical approach, based on a dimensionless diffusion model ( Weinbaum and Goldgraben, 1972 ) has yielded results which are in close agreement with experimental data for both living and dead eyes. It is concluded that the formation of the aqueous humor is a pressure dependent mechanism associated with an active transport of solute; the latter being responsible for 30–40% of the total flow. In keeping with present concepts of solute-water coupled flow in epithelial systems it is assumed that the solute is actively transported into the extracellular channels of the ciliary epithelium from the adjacent cells and that the water movement is passive.
Links between oestrogen receptor activation and proteolysis: relevance to hormone-regulated cancer therapy

Oestrogen receptor-α (ERα) is a master transcription factor that regulates cell proliferation and homeostasis in many tissues. Despite beneficial ERα functions, sustained oestrogenic exposure increases the risk and/or the progression of various cancers, including those of the breast, endometrium and ovary. Oestrogen–ERα interaction can trigger post-translational ERα modifications through crosstalk with signalling pathways to promote transcriptional activation and ubiquitin-mediated ERα proteolysis, with co-activators that have dual roles as ubiquitin ligases. These processes are reviewed herein. The elucidation of mechanisms whereby oestrogen drives both ERα transactivation and receptor proteolysis might have important therapeutic implications not only for breast cancer but also potentially for other hormone-regulated cancers.
Analysis of amplitude-quantized sampled-data systems

QUANTIZATION, or round-off, takes place whenever physical quantities are represented numerically. A quantizer is an operator that assigns a value to a variable equal to its closest integer. Analog-to-digital conversion consists of both sampling and quantizing.
The multifunctional role of C3: structural analysis of its interactions with physiological ligands.

Of the 20 distinct complement proteins recognized to date, C3 is probably the most versatile because of its pivotal role in both the classical and alternative pathways (for review, see Muher-Eberhard, 1975; Porter and Reid, 1979). Therefore, the structure and multiple functions of C3 have been the subject of intensive study. C3 [molecular weight (mol. wt) 190,000], the most abundant complement protein in serum (I .2 mm Law et al., 1979; Tack et al., 1980) to cell surfaces, complex polysaccharides or immune aggregates. Unlike native C3, and C3b fragment expresses multiple binding sites, including sites for C5 (Vogt et al., 1978), properdin (P) (Chapitis and Lepow, 1976; Schreiber et al., 1975), factor H (Whaley and Ruddy. 1976; Weiler et al., 1976), factor I3 (Fearon et al., 1973; Brade et al., 1973), factor I (Vogt et al., 1977) and CRl, the C3b receptor (Nelson, 1953: Gigli and Nelson, 1968). Engagement of the binding sites on C3b has the following effects. Bound factor B becomes susceptible to cleavage and activation by factor D. Bound P stabilizes the resulting C3 convertase, bound C5 can be activated by C3b. Bb or C4b. 2a. Binding of factor H accelerates the decay-dissociation of the C3 convertase and modulates C3b for enzymatic degradation by factor I. Engagement of target cell-bound C3b with the CR1 on phagocytic cells causes cell adhesion, which may induce ingestion or extracellular killing. Many of the activities exhibited by bound C3b are
Effects of tranylcypromine and pargyline on brain tryptamine

Tranylcypromine produces behavioral excitation while pargyline produces depression. Tranylcypromine increased brain tryptophan which led to an accumulation of tryptamine. The levels of tryptamine after tranylcypromine were found to be 3 times those found after pargyline.
Central Control System of the NAL Accelerator

This paper describes the central control system now being built and used to operate the completed parts of the NAL accelerator. This control system may be of some interest because new methods of monitoring and control are made necessary by the greatly increased size and complexity of the NAL accelerator compared with other synchrotrons. The primary design goal for the NAL control system is that eventually, during routine operation, one person be able to operate the entire accelerator: preaccelerator, linear accelerator, booster synchrotron, main synchrotron and beam-extraction and transport systems. But it is also necessary that several operators be able simultaneously to interrogate and control different parts of the accelerator for maintenance, diagnosis of equipment problems, bringing new devices on, and for accelerator-development studies. To attain these goals, a computer-assisted system has been designed and is being built. This system has several levels of organization, and it is desirable that control be possible at more than one level, in order to avoid shutdowns caused by higher-level equipment failures. The system must also be flexible enough to accommodate the new devices we expect will be added as the accelerator is developed. This paper includes an overall description of the control system, and details of some of its special features.
Frame work for real time Optimal Power Flow using real time measurement tools and techniques

The present power grid is complex due to enormous real time applications and hence requires new developmental areas of smart grid. As such, the grid which has been slowly becoming ‘modernized’ to meet the new challenges is overly stressed. In a bid to develop enabling technologies so as to address the mitigation of the various stresses the power grid faces, there arises a need for monitoring and control scheme for real-time operation [1] and applications. This will necessitate a primary aim which is to provide preventative monitoring and controls rather than corrective control. The enhanced grid requires new optimization techniques as well. This paper reviews new measurement techniques and tools with real time applications to Optimal Power Flow (OPF) algorithm with vulnerability, survivability and reliability as measures of performance indices.
A new coupled, one-dimensional biological-physical model for the upper ocean: Applications to the JGOFS Bermuda Atlantic Time-series Study (BATS) site

Abstract This paper presents a new coupled, one dimensional biological-physical model applied to the subtropical region near Bermuda. The physical component of the model, which is driven by smooth climatological forcing, successfully reproduces the long-term seasonal cycles of upper ocean temperature, salinity and boundary layer depth from Hydrostation S. The nitrogen-based biological model, which includes the effects of photoadaptation, phytoplankton aggregation, and particle remineralization in the aphotic zone, shows significant skill in capturing the major features of the annual chlorophyll field (e.g. spring bloom, deep chlorophyll maximum) and depth-integrated chlorophyll and primary production as exhibited by the U.S. JGOFS Bermuda Atlantic Time-series Study (BATS) data. The introduction of variable phytoplankton chlorophyll-to-nitrogen ratios is found to be important for simulating the subsurface chlorophyll maximum, and the model solutions show a realistic deep nitracline in the summer and a low annual average f -ratio of ∼0.21 compared to previous modeling work. The performance of the model solutions are weakest during the late summer, when the model can not supply enough nutrients to support the high production observed in the stratified near-surface waters. The coupled model has large winter production values, leading to a substantial export of organic material from the euphotic zone via downward turbulent mixing. The model predicts a total export production from the euphotic zone of 0.24 mol N m −2 year −1 , approximately equally partitioned between particle sinking and suspended matter detrainment. The bulk of the export production is remineralized in the shallow aphotic zone, and only a small fraction is transported below the depth of the maximum winter mixed layer and thus contributes to “biological pump”.
Modulation of Nuclear Receptor Interactions by Ligands: Kinetic Analysis Using Surface Plasmon Resonance†

Many nuclear hormone receptors, including the human 1,25-dihydroxyvitamin D3 receptor (VDR), bind cooperatively to DNA as either homodimers or heterodimers with the 9-cis-retinoic acid receptor (RXR). Protein−protein interactions mediated by residues within both the DNA- and ligand-binding domains contribute to this binding. We have previously reported that the ligands for VDR and RXR can modulate the affinity of the receptors' interaction with DNA [Cheskis, B., & Freedman, L. P. (1994) Mol. Cell. Biol. 14, 3329−3338]. To examine this in more detail, we report here the use of surface plasmon resonance (SPR) to characterize the kinetics of both protein−protein and protein−DNA interactions by VDR and RXR in the presence and absence of their cognate ligands. We find that 1,25 dihydroxyvitamin D3 binding favors both VDR−RXR heterodimerization and, as a result, DNA binding by the complex. Conversely, the ligand reduces VDR homodimerization in solution and the affinity of VDR−DNA interaction. 9-cis-Retinoic aci...
Measures needed to strengthen strategic HIV/AIDS prevention programmes in China.

This paper traces the commonly believed three phases of the HIV/AIDs epidemic in China from the early 1980s to the present time and reviews how the Chinese Government and NGOs are dealing with the crisis. Transmission routes for HIV infection in China are thought to be via IDUs blood plasma donors sexual contacts and from mother-to-child transmissions. The author examined interventions for HIV/ AIDS prevention tried in other countries that could provide useful lessons learned and discussed how they could be adapted or replicated in China. While recognising the need for the treatment of HIV positive persons and AIDS patients this paper is limited to suggesting a number of proven strategic interventions to prevent new HIV infections in China among the "general population" adolescents in schools sex workers and their clients injecting drug users and prevention of mother to child transmission of HIV/AIDS to stem the epidemic. An extensive literature search of articles in published academic journals published and unpublished documents of international agencies and development NGOs and media reports was conducted for data source to this paper. Internet search engines such as ProQuest PubMed Google and Yahoo search engines were used as well as hard copies of reports and internal documents available at the UNFPA Country Technical Services Teams Office in Bangkok tapped for information. (authors)
Sleep-related gastroesophageal reflux: Clinical and physiologic consequences

This review addresses the changes in the physiologic responses to esophageal acid contact that occur during sleep. The importance of these changes is addressed as they pertain to the development of esophagitis and other complications of gastroesophageal reflux. Sleep results in physiologic changes that impair esophageal acid clearance, thereby creating a vulnerability to the complications of reflux. These complications are generally considered secondary to prolonged acid mucosal contact. Sleep-related reflux also disrupts sleep, which may result in clinical complaints of sleep disturbance and significant daytime consequences, such as sleepiness and diminished work performance. The significance of these sleep-related findings is addressed in the context of the diagnosis and treatment of GERD.
Microfluidics in structural biology: smaller, faster ... better

Microfluidic technologies promise unprecedented savings in cost and time through the integration of complex chemical and biological assays on a microfabricated chip. Recent advances are making elements of this vision a reality, facilitating the first large-scale integration of microfluidic plumbing with biological assays. The power of miniaturization lies not only in achieving an economy of scale, but also in exploiting the unusual physics of fluid flow and mass transport on small length scales to realize precise and efficient assays that are not accessible with macroscopic tools. Diverse applications ranging from time-resolved studies of protein folding to highly efficient protein crystal growth suggest that microfluidics may become an indispensable tool in biology.
Minimizing the Wick Thickness in a Planar Microscale Loop Heat Pipe Using Efficient Thermodynamic Design

Theoretical and numerical thermodynamic analysis of the evaporator section of a planar microscale loop heat pipe is presented, to minimize the permissible wick thickness in such a device. In conventional cylindrical loop heat pipes, a minimum wick thickness is required in order to reduce parasitic heat flow, and prevent vapor leakage, into the compensation chamber. By taking advantage of the possibilities allowed by microfabrication techniques, a planar evaporator/compensation chamber design topology is proposed to overcome this limitation, which will enable wafer-based loop heat pipes with device thicknesses on the order of a millimeter or less. Thermodynamic principles governing two-phase flow of the working fluid in a loop heat pipe are analyzed to elucidate the fundamental requirements that would characterize the startup and steady state operation of a planar phase-change device. A three dimensional finite element thermal-fluid solver is implemented to study the thermal characteristics of the evaporator section and compensation chamber regions of a planar vertically wicking micro-columnated loop heat pipe. The use of in-plane thermal conduction barriers to reduce parasitic heat flow into the compensation chamber is demonstrated.Copyright © 2011 by ASME
An O(n log m) algorithm for the Josephus Problem

Abstract The Josephus Problem can be described as follows: There are n objects arranged in a circle. Beginning with the first object, we move around the circle and remove every m th object. As each object is removed, the circle closes in. Eventually, all n objects will have been removed from the circle. The order in which the objects are removed induces a permutation on the integers 1 through n . Knuth has described two O ( n log n ) algorithms for generating this permuation. The problem of determining a more efficient algorithm for generating the permutation is left open. In this paper we give an O ( n log m ) algorithm.
The Kinetics of Nucleated Polymerizations at High Concentrations: Amyloid Fibril Formation Near and Above the “Supercritical Concentration”

The formation of amyloid and other types of protein fibrils is thought to proceed by a nucleated polymerization mechanism. One of the most important features commonly associated with nucleated polymerizations is a strong dependence of the rate on the concentration. However, the dependence of fibril formation rates on concentration can weaken and nearly disappear as the concentration increases. Using numerical solutions to the rate equations for nucleated polymerization and analytical solutions to some limiting cases, we examine this phenomenon and show that it is caused by the concentration approaching and then exceeding the equilibrium constant for dissociation of monomers from species smaller than the nucleus, a quantity we have named the “supercritical concentration”. When the concentration exceeds the supercritical concentration, the monomer, not the nucleus, is the highest-energy species on the fibril formation pathway, and the fibril formation reaction behaves initially like an irreversible polymerization. We also derive a relation that can be used in a straightforward method for determining the nucleus size and the supercritical concentration from experimental measurements of fibril formation rates.
Role playing and group experience to facilitate attitude and value changes among Black and White police officers.

White and black police officers were seen in weekly sessions involving role playing and interpersonal feedback during academy training, the purpose being to improve communication and relationships between black and white officers. Contrary to expectation, white officers became both more sensitized to the presence of black-white problems and more prejudiced toward blacks, whereas black officers who attended became more positive toward whites. It was felt that results were due in part to a perception by white officers that the program was initiated for the benefit of blacks rather than for all.
Spatial genetic structure of bristle-thighed curlews (Numenius tahitiensis): breeding area differentiation not reflected on the non-breeding grounds

Migratory birds occupy geographically and ecologically disparate areas during their annual cycle with conditions on breeding and non-breeding grounds playing separate and important roles in population dynamics. We used data from nuclear microsatellite and mitochondrial DNA control region loci to assess the breeding and non-breeding spatial genetic structure of a transoceanic migrant shorebird, the bristle-thighed curlew. We found spatial variance in the distribution of allelic and haplotypic frequencies between the curlew’s two breeding areas in Alaska but did not observe this spatial structure throughout its non-breeding range on low-lying tropical and subtropical islands in the Central Pacific (Oceania). This suggests that the two breeding populations do not spatially segregate during the non-breeding season. Lack of migratory connectivity is likely attributable to the species’ behavior, as bristle-thighed curlews exhibit differential timing of migration and some individuals move among islands during non-breeding months. Given the detrimental impact of many past and current human activities on island ecosystems, admixture of breeding populations in Oceania may render the bristle-thighed curlew less vulnerable to perturbations there, as neither breeding population will be disproportionally affected by local habitat losses or by stochastic events. Furthermore, lack of migratory connectivity may enable bristle-thighed curlews to respond to changing island ecosystems by altering their non-breeding distribution. However, availability of suitable non-breeding habitat for curlews in Oceania is increasingly limited on both low-lying and high islands by habitat loss, sea level rise, and invasive mammalian predators that pose a threat to flightless and flight-compromised curlews during the molting period.
Learning to detour

Anurans (frogs and toads) show quite flexible behavior when confronted with stationary objects on their way to prey or when escaping from a threat. Rana computatrix (Arbib, 1987), an evolving computer model of anuran visuomotor coordination, models complex behaviors such as detouring around a stationary barrier to get to prey on the basis of an understanding of anuran prey and barrier recognition, depth perception, and appropriate motor pattern generation mechanisms based on sensory perception. Our present analysis of detour behavior goes beyond other models by incorporating new data from our laboratory demonstrating a learning component in anuran detour behavior. Building on earlier work showing how interacting schemas may be used to analyze a complex environment to generate an appropriate course of behavior, we turn to the questions: How are the relevant schemas adapted? How are schemas combined to form new schema assemblages acquired for the system to become more efficient? We describe the construction...
The Resummation of One Particle Lines

We propose a partial resummation for a weak coupling cluster expansion. The resummation gives one particle lines with in/out field propagators. We give a Bethe-Salpeter equation in which one particle subtractions are defined using physical one particle states. By these methods, we show thatP(φ)2 quantum fields in the weak coupling region have only isolated bound state spectrum below the 2m threshold. HereP is not restricted to be even.
Designing multistatic ultrasound imaging systems using software analysis

This paper describes the method of using the finite-element analysis software, PZFlex, to direct the design of a novel ultrasound imaging system which uses conformal transducer arrays. Current challenges in ultrasound array technology, including 2D array processing, have motivated exploration into new data acquisition and reconstruction techniques. Ultimately, these efforts encourage a broader examination of the processes used to effectively validate new array configurations and image formation procedures. Commercial software available today is capable of efficiently and accurately modeling detailed operational aspects of customized arrays. Combining quality simulated data with prototyped reconstruction techniques presents a valuable tool for testing novel schemes before committing more costly resources. To investigate this practice, we modeled three 1D ultrasound arrays operating multistatically instead of by the conventional phased-array approach. They are: a simple linear array, a half-circle array with 180-degree coverage, and a full circular array for inward imaging. We present the process used to create unique array models in PZFlex, simulate operation and obtain data, and subsequently generate images by inputting data into a reconstruction algorithm in MATLAB. Further discussion describes the tested reconstruction algorithm and includes resulting images.
A factor analysis of the Klein sexual orientation grid in two disparate samples

Many researchers interested in sexual orientation can be separated into two camps: The “lumpers,” who try to reduce sexual classifications to as small a number of categories as possible, and the “splitters,” who try to show differences among groups and individuals that make classification schemes increasingly difficult and/or intricate. We report factor analyses of the Klein Grid (a questionnaire with 21 sexual orientation items) to see how many factors emerge in two samples of strikingly different origins. In both samples, the first factor to emerge loaded substantially on all of the Klein Grid's 21 items. This factor accounted for a majority of the variance. In both samples, a second, correlated factor emerged which indexed a separation between most of the items and those having to do with social and/or emotional preferences. In both samples, a third correlated factor also emerged, but this factor differed between the two populations: one refined the social/emotional distinction and the other distinguished ideal behavior from past and current behavior. We conclude on the basis of our analysis that both the lumpers and the splitters are correct.
Endoscopic and histologic diagnosis of intestinal graft-versus-host disease after marrow transplantation.

Abstract Background: Gastrointestinal graft-versus-host disease after allogeneic hematopoietic cell transplantion presents a range of upper gastrointestinal endoscopic and histologic abnormalities. Recognition of these sometimes subtle abnormalities is critical for directing specific therapy. Methods: Endoscopic and histologic abnormalities in 10 patients with gastrointestinal graft-versus-host disease are reviewed to detail the spectrum of findings. Results: The endoscopic appearance of the stomach and duodenum varies from subtle mucosal erythema and edema to frank ulceration and mucosal slough. Histologic findings include crypt epithelial cell apoptosis and dropout, crypt destruction, and variable lymphocytic infiltration of the epithelium and lamina propria. The involvement may vary from diffuse and uniform to focal, with either the stomach or the duodenum appearing much more involved. Conclusions: Endoscopic evaluation of the stomach and duodenum and histologic evaluation of biopsies of the gastric antrum can be used to diagnose gastrointestinal graft-versus-host disease. The gross appearance of the mucosa and the histology of gastric biopsies are mutually complementary. However, both the endoscopic evaluation and the histology of the upper gut can underestimate the severity of acute graft-versus-host disease elsewhere in the intestine unless extensive mucosal sloughing is seen. (Gastrointest Endosc 1999;49:612-21.)
Nafion®/poly(vinyl alcohol) blends: Effect of composition and annealing temperature on transport properties

Abstract In this study, the transport properties (proton conductivity and methanol permeability) of Nafion® 117, solution-cast Nafion®, poly(vinyl alcohol) (PVA) and Nafion®/PVA blend membranes were measured as a function of annealing temperature (60–250 °C) and blend composition for application to the direct methanol fuel cell (DMFC). A Nafion®/PVA blend membrane at 5 wt% PVA (annealed at 230 °C) resulted in similar proton conductivity, but three times lower methanol permeability compared to Nafion® 117. In addition, an unusual trend was observed in Nafion®/PVA (50 wt% PVA) blend membranes, where proton conductivity remained relatively constant, but methanol permeability decreased by approximately one order of magnitude with increasing annealing temperature. Infrared spectroscopy reveals a band shift in the hydroxyl peak to higher wavenumbers in Nafion®/PVA blends (25–90 wt% PVA) with increasing annealing temperature suggesting an increase in the interaction between the hydroxyl groups in PVA and the sulfonic acid groups in Nafion®. For Nafion® alone, proton and methanol transport rates increased and then decreased with increasing annealing temperature with a maximum at 210 °C for both solution-cast and as-received (extruded) Nafion®. This trend coincides with two transition temperatures observed by other investigators using differential scanning calorimetry, suggesting that transport properties are affected by morphological changes in Nafion®.
Using the Distractor Categories of Multiple-Choice Items to Improve IRT Linking

Simulation and real data studies are used to investigate the value of modeling multiple-choice distractors on item response theory linking. Using the characteristic curve linking procedure for Bock's (1972) nominal response model presented by Kim and Hanson (2002), all-category linking (i.e., a linking based on all category characteristic curves of the linking items) is compared against correct-only (CO) linking (i.e., linking based on the correct category characteristic curves only) using a common-item nonequivalent groups design. The CO linking is shown to represent an approximation to what occurs when using a traditional correct/incorrect item response model for linking. Results suggest that the number of linking items needed to achieve an equivalent level of linking precision declines substantially when incorporating the distractor categories.
Clinical centers for oral research

Research centers, in which clinical and basic scientists join resources, offer su­ perior advantages for profound and systematic study, and for coordinating clinical and fundamental investigations. The mechanisms whereby centers of medical research have been established have not yet been exploited for the ad­ vancement of dental research. Such cen­ ters could conduct coordinated, intensive research in periodontal disease, dental caries, soft tissue diseases of the mouth, restorative technics and materials, con­ genital defects of the oral structures, and oral problems of childhood and old age.
Current status of the HERACLES, a millijoule level, multi kHz, few-cycle, and CEP stabilized OPCPA system

A cryogenic-cooling free, few-cycle, carrier-envelope-phase stabilized OPCPA designed to operate at repetition rates as high as 25 kHz with millijoule level energy is presented. Motivation, design issues and current state of the system are reported.
Acute effects of irradiation on cognition: changes in attention on a computerized continuous performance test during radiotherapy in pediatric patients with localized primary brain tumors.

Abstract Purpose: To assess sustained attention, impulsivity, and reaction time during radiotherapy (RT) for pediatric patients with localized primary brain tumors. Methods and Materials: Thirty-nine patients (median age 12.3 years, range 5.9–22.9) with primary brain tumors were evaluated prospectively using the computerized Conners' continuous performance test (CPT) before and during conformal RT (CRT). The data were modeled to assess the longitudinal changes in the CPT scores and the effects of clinical variables on these changes during the first 50 days after the initiation of CRT. Results: The CPT scores exhibited an increasing trend for errors of omission (inattentiveness), decreasing trend for errors of commission (impulsivity), and slower reaction times. However, none of the changes were statistically significant. The overall index, which is an algorithm-based weighted sum of the CPT scores, remained within the range of normal throughout treatment. Older patients (age >12 years) were more attentive ( p p p p p p p p p p Conclusion: Children with brain tumors have problems with sustained attention and reaction time resulting from the tumor and therapeutic interventions before RT. The reaction time slowed during treatment for patients
The fidelity of DNA synthesis by the catalytic subunit of yeast DNA polymerase α alone and with accessory proteins

The fidelity of DNA synthesis catalyzed by the 180-kDa catalytic subunit (p180) of DNA polymerase alpha from Saccharomyces cerevisiae has been determined. Despite the presence of a 3'----5' exonuclease activity (Brooke et al., 1991, J. Biol. Chem., 266, 3005-3015), its accuracy is similar to several exonuclease-deficient DNA polymerases and much lower than other DNA polymerases that have associated exonucleolytic proofreading activity. Average error rates are 1/9900 and 1/12,000, respectively, for single base-substitution and minus-one nucleotide frameshift errors; the polymerase generates deletions as well. Similar error rates are observed with reactions containing the 180-kDa subunit plus an 86-kDa subunit (p86), or with these two polypeptides plus two additional subunits (p58 and p49) comprising the DNA primase activity required for DNA replication. Finally, addition of yeast replication factor-A (RF-A), a protein preparation that stimulates DNA synthesis and has single-stranded DNA-binding activity, yields a polymerization reaction with 7 polypeptides required for replication, yet fidelity remains low relative to error rates for semiconservative replication. The data suggest that neither exonucleolytic proofreading activity, the beta subunit, the DNA primase subunits nor RF-A contributes substantially to base substitution or frameshift error discrimination by the DNA polymerase alpha catalytic subunit.
The effect of β-mercaptoethanol on synchronously dividing populations of Astasia longa☆

Abstract Cell division can be reversibly blocked by β-mercaptoethanol in Astasia longa synchronized by temperature shifts. Division may or may not take place during the first high temperature period after mercaptoethanol addition depending on the length of exposure, population density, and the mercaptoethanol concentration. With the concentrations employed, division does not occur in the second high temperature period after treatment. This is true as well when the inhibitor is removed from the cultures prior to the onset of this warm period. When the cells are washed free of mercaptoethanol prior to the second high temperature period after addition of 10−3 M mercaptoethanol, a burst of cell division takes place beginning in the third high temperature period. Prior to this burst, the cells are abnormally large and during the burst, synchrony is lost.
Understanding environmental adaptation of the fungal circadian clock with mathematical modeling.

The circadian clock generates 24-h rhythms that provide robust regulation of a variety of physiological and behavioral processes in a diverse range of organisms, including the fungus Neurospora, the plant Arabidopsis, the fly Drosophila, and mammals. While each organism has evolved unique molecular machinery to generate these rhythms, most circadian clocks are composed of interconnected transcriptional and translational feedback loops. The clock must generate robust 24-h rhythms, entrain its rhythms to the prevailing light-dark cycle, and adapt to various other environmental perturbations.
INTERFERENCE WITH THE ALTERNATE PATHWAY OF COMPLEMENT ACTIVATION DURING TRANSPLANT REJECTION

During the rejection of an allotransplant, there appears in the circulation a material which interferes with the alternate pathway of complement activation. This material also deposits on the graft and may be eluted and further purified by gel filtration. When added to normal human serum and zymosan, the rate of C3-C9 hemolytic consumption is retarded. This appears to result from an inhibition of the early steps in the alternate pathway leading to the initial generation of C3b and activation of C3 proactivator. Thus, this material can prevent C3-C9 hemolytic consumption when added to a mixture of activated properdin convertase and normal human serum. Initial activation of properdin convertase by zymosan is not affected. Separation and culture of peripheral lymphocytes from patients rejecting a transplant show that there is elaboration of the material responsible for the interference with the alternate pathway activity. Removal of 85-95% of B cells by passage over antigen-antibody-complement coated columns does not prevent this generation suggesting that T cells may be responsible. This data may, therefore, represent evidence for a link between T cell function and the alternate pathway of complement activation in graft rejection. (Supported in part by N1AMD grant AM 17376)