cssi/SciSciGPT-SciSciNet huggingface dataset:
Calcium-dependent regulation of rat and chick muscle nicotinic acetylcholine receptor (nAChR) gene expression

Muscle depolarization leads to decreased expression of nicotinic acetylcholine receptor (nAChR) genes in extrajunctional regions of the muscle fiber with little effect on their expression at the neuromuscular junction (NMJ). Depolarization-dependent decreases in nAChR gene expression have been linked to a cAMP-dependent signaling system in rat (Chahine, K. G., Baracchini, E., and Goldman, D. (1993) J. Biol. Chem. 2893-2898), and a calcium-dependent protein kinase C (PKC) signaling system in chick (Klarsfeld, A., Laufer, R., Fontaine, B., Devillers-Thiery, A., Bubreuil, C., and Changeux, J. P. (1989) Neuron 2, 1229-1236). We report here on experiments investigating the role of calcium and PKC in regulating rat muscle nAChR gene expression. These studies indicate that depolarization-dependent regulation of rat muscle nAChR gene expression is independent of PKC activity. However, these genes are regulated by a calcium-dependent signal transduction system. Calcium influx across the plasma membrane decreases nAChR gene expression in inactive rat myotubes. Surprisingly, this influx of extracellular calcium is most effective at reducing nAChR epsilon-subunit gene expression. We also provide evidence that a similar signal transduction system is capable of regulating nAChR gene expression in chick muscle. Based on these data we propose that calcium, in addition to mediating depolarization-dependent regulation of nAChR expression, may also participate in restricting their expression to the neuromuscular junctions of adult muscle fibers.
The navigation of autonomous vehicles in uncertain dynamic environments: a case study

This paper proposes a method for building with multiple vehicles a probability map of uncertain dynamic environments. It is assumed that each vehicle has a limited sensor range and therefore lacks global information. The vehicles share their measurement information to build a probability map. The probability map is updated using sensor information and a priori statistics of the dynamic environment.
Survivor Studio @ Philadelphia University: Promoting sustainability in the design studio through collaborative game playing

The paper describes how, in the first few weeks of each semester, the architecture students and faculty at Philadelphia University participate in a Survivor Competition. Inspired by the campy show where contestants battle the elements and each other for a million dollars, Survivor Studio pits teams of design students and faculty against each other to accumulate points in a variety of physical, intellectual and design challenges. Geared towards heightening the students’ respect for natural systems, understanding of indigenous cultures and the poetic potential for sustainable technologies, the challenges attempt to develop relationships with the students’ non‐design studio curriculum. This included a game show on the history of architecture, the reading and interpretation of a novel called Ishmael: An Adventure of the Mind and Spirit, and a research documentation project focused on sustainable architecture and technologies developed by indigenous cultures. Physical challenges included scavenger hunts around campus that highlighted strategy, teamwork and knowledge/sensitivity to local environments. The main challenge for the students was to design a small community that could sustain the team without food or power or any supplies for one year. It elaborates on the ideas, pedagogical concepts, teaching strategies and eventual results of the Survivor Studio as a vehicle for exploring new and innovative ways to activate students’ imagination, energy and innate knowledge about sustainable design.
Social media's contribution to customer satisfaction with services

An important recent initiative in the effective transmission of healthcare services is the establishment of the patient-centered medicine (PCM) philosophy as a mechanism for enhancing customer satisfaction. Although the goals of PCM are important, there is less understanding of the means by which service providers can promote this philosophy.This study examines the relationship between customers’ attitude toward and use of social media, PCM, and their satisfaction with healthcare services. Data were collected from a large, urban-based pediatric office in the northeast. The sample consisted of 234 respondents who were classified as ‘e-Patients’ – that is, they reported having access to the Internet and going online for health information. A three-stage regression analysis, conducted to establish the path coefficients for each stage in the model, shows that customers’ (patients’) attitude toward social media can be an effective method to enhance PCM and, ultimately, satisfaction. The findings contribute to ...
To What Extent Can Definitions Help our Understanding? What Plato Might Have Said in His Cups

This article argues that philosophical definitions are overrated as sources of understanding or wisdom. Socrates gives a standard argument in their favor which is often still proffered. Still, that Socrates's definitions never succeed invites an ironic reading of that argument. Plato also gives crucial arguments against treating definitions as important to understanding, and those objections have current versions. That raises an issue: What did we think definitions would do for us anyway? That question invites a reassessment of definitions that makes them less central and gives them a more humble, though still dangerous, role to play, one that requires they be integrated with surrounding examples and our own complex educations toward wisdom.
Achieving stretched capacity goal through integrated engineering and manufacturing excellence

Achieving stretched equipment capacity and high productivity in high volume manufacturing is a gritty challenge to drive down cost continuously in this competitive chipset market. With unprecedented volume ramp of both key products in Q4'99, the Test Module faced a shortage of two to four testers. Driving through working group, a refurbishment process was achieved successfully resulting in 60% reduction of tester faults thus improving mean time between failure (MTBF) from 140 hrs to 160 hrs. With the implementation of improved pogo pins at Tester Interface Unit (TIU) and test head had improved cleaning frequency from 5 k to 90 k, one-sum test yield from 88.7% to 97.5% and reduced non-genuine SBL from 10% to less than 3% consistently.
Extending Lego® My Simplex

Almost 20 years have passed since Pendegraft described his use of Lego® toys to teach students basic modeling skills and linear programming concepts. Since then, many instructors of operations research including the author and their students have benefited from his contribution. In this article, the author describes a series of extensions he has developed since originally implementing Pendegraft's active learning exercise in the introductory operations courses he teaches. Through these extensions, the author integrates the concepts of sensitivity, integer programming, and LP formulation and extends the modeling experience beyond the original exercise.
Lattice vibrations of MgAl2O4 spinel

Abstract Raman spectra have been measured on oriented single crystals of MgAl2O4 spinel. The fundamental frequencies are A1g = 772, Eg = 410, and T2g = 671, 492 and 311 cm−1. A Kramers-Kronig analysis of the reflectance spectrum of spinel yields the i. r. -active vibrations T1u = 670, 485, 428 and 305 cm−1.
Changes in unreacted starch content in corn during storage

In the dry grind process, corn is ground, mixed with process water and cooked; starch is enzymatically hydrolyzed to sugars, and subsequently fermented to ethanol by yeast. The conversion of starch into ethanol, however, is not complete as distillers dried grains with solubles (DDGS) often contain more than 5% starch. The amount of unreacted starch represents inefficiencies in the process and reducing this amount is important to improving profitability of the ethanol industry. Additionally, dry grind facilities have reported seasonal variation in ethanol yields. In order to minimize variation in ethanol yields and the amount of unreacted starch in DDGS, it is important to understand the effects that storage temperature and time have on the digestibility of the corn starch. While starch quality is largely controlled by genetics and growing conditions, postharvest practices (handling, storage, and processing conditions) also affect starch composition and structure. In this study, changes in unreacted starch content of corn during storage were monitored to provide an explanation for the seasonal variation in ethanol yields observed by dry grind facilities. Yellow dent corn was harvested in 2011 and 2012 and stored indoors, outdoors, and under refrigeration for 5–12 mo. Results with the 2011 harvest corn showed unreacted starch content ranging from 2.17 to 14.1% over a 48 wk period. Unreacted starch was more influenced by storage time, initially decreasing at a rate of 0.31% per wk during the first 10 wk and steadily increased at an average rate of 0.16% per wk for the duration of storage. Results with the 2012 harvest corn, however, showed a higher average unreacted starch content of 13.0% during 20 wk of storage and no appreciable change in unreacted starch content regardless of storage temperature.
A-Cache: Resolving cache interference for distributed storage with mixed workloads

Distributed key-value stores employ large main memory caches to mitigate the high costs of disk access. A challenge for such caches is that large scale distributed stores simultaneously face multiple workloads, often with drastically different characteristics. Interference between such competing workloads leads to performance degradation through inefficient use of the main memory cache. This paper diagnoses the cache interference seen for representative workloads and then develops A-Cache, an adaptive set of main memory caching methods for distributed key-value stores. Focused on read performance for common workload patterns, A-Cache leads to throughput improvements of up to 150% for competing data-intensive applications running on server class machines.
A radiochemical neutron activation analysis method for the determination of total mercury in coal

A radiochemical neutron activation analysis method has been developed based on pyrolysis followed by double gold amalgamation for the determination of mercury in solid samples. Accurate results were obtained for mercury in six standard reference materials of varying matrices, including coal. Linearity was demonstrated up to mercury concentrations of 10,000 ng/g. The method is capable of yielding precise, reproducible values with a detection limit of 5 ng/g for mercury in coal.
A numerical methodology for investigating the formation of adiabatic shear bands

In this paper, we present a numerical approach for analyzing thermo-visco-plastic deformation in one dimension. The method, which is accurate to second order, is based on integration along the characteristic lines. It is able to simulate fully localized plastic flow with high resolution and good efficiency. We apply this numerical scheme to the analysis of shear localization, emphasizing the interactions between a single shear band and its surroundings and among the members of a periodic array of shear bands. It is found that a shear band may grow intermittently due to interactions with other bands. The developed method is specifically adequate for analyzing the self-organized multiple adiabatic formation process, which will be discussed in the follow-up paper.
Effects of the murine mutation 'nervous' on neurons in cerebellum and dorsal cochlear nucleus.

‘Nervous’ mutant mice are presently available on two different genetic background strains which are derived from out-breeding of the original BALB/cGr mutant stock. Light and electron microscopic studies of these mutants demonstrate that cerebellar Purkinje cells and cartwheel neurons of the dorsal cochlear nucleus (DCoN) show similar, albeit not identical, cytoplasmic and mitochondrial alterations in both background strains. In the cerebellar cortex, all Purkinje cell perikarya developed a varying number of enlarged and rounded mitochondria, as previously described. Extensive changes were observed in various components of the mitochondrial matrix. As cellular degeneration proceeded, reduction, fragmentation and dilation of cisterns of endoplasmic reticulum and the Golgi apparatus were evident. Some of the mitochondria underwent a peculiar type of degeneration, i.e. the outer membrane partially or completely dissolved, occasionally accompanied by focal interruptions of the inner membrane. In older adult mutants only 10% of cerebellar Purkinje cells rehained. The few surviving cells displayed varying states, ranging from essentially normal ultrastructure to electron-dense condensation. Many of these cells, in both strains, continued to display greatly enlarged, rounded mitochondrial profiles, indicating a change in the expression of the gene defect resulting from genetic contamination. Criteria for the identification of neuronal cell classes in layers 1 and 2 of murine DCoN were established. Cartwheel neurons in the mutant DCoN presented alterations similar to those observed in cerebellar Purkinje cells. The characteristic mitochondrial anomaly developed and proceeded in cartwheel neurons within a comparable time frame. The vast majority of affected cartwheel cells did not undergo degeneration, however, but continued to possess altered mitochondria into adulthood. The differences between normal and mutant mitochondria in Purkinje and cartwheel cells were quantified by morphometric analyses. Our findings lend support to the notion of a homology between cerebellar Purkinje cells and DCoN cartwheel cells. These cells represent major elements in two similar spatially related circuits, and share several genetic, structural and neurochemical properties. It is therefore proposed that these two cell populations are derived from closely related precursor cells.
Analytical Seismic Fragility Analyses of Fire Sprinkler Piping Systems with Threaded Joints

For the first time, an analytical modeling methodology is developed for fire sprinkler piping systems and used to generate seismic fragility parameters of these systems. The analytical model accoun...
Observation of the dissolution of NAPL mixtures

Abstract The process of NAPL dissolution has been studied extensively for petroleum products where the solvent mixtures are lighter than water, but less has been done for dense solvents. An experiment to quantitatively measure the dissolution behaviour for mixtures of dense and light, chlorinated and non-chlorinated hydrocarbons, represented by an equimolar mixture of 1,1,1-trichloroethane, tetrachloroethene, 1,1,2-trichloro-1,2,2-trifluoroethane and toluene, was undertaken. The experimental system consisted of a generator column and a constant-head-space flow cell, sampled automatically and analysed using a portable gas chromatograph. The effect of ionic strength on the dissolution of the solvents was measured. Activity coefficients of the solvents in the mixture were calculated and compared with UNIFAC© predictions.
Copy number change: evolving views on gene amplification

The rapid pace of genomic sequence analysis is increasing the awareness of intrinsically dynamic genetic landscapes. Gene duplication and amplification (GDA) contribute to adaptation and evolution by allowing DNA regions to expand and contract in an accordion-like fashion. This process affects diverse aspects of bacterial infection, including antibiotic resistance and host-pathogen interactions. In this review, microbial GDA is discussed, primarily using recent bacterial examples that demonstrate medical and evolutionary consequences. Interplay between GDA and horizontal gene transfer further impact evolutionary trajectories. Complementing the discovery of gene duplication in clinical and environmental settings, experimental evolution provides a powerful method to document genetic change over time. New methods for GDA detection highlight both its importance and its potential application for genetic engineering, synthetic biology and biotechnology.
Microenvironmental Control of the Breast Cancer Cell Cycle

The mammary gland is one of the best-studied examples of an organ whose structure and function are influenced by reciprocal signaling and communication between cells and their microenvironment. The mammary epithelial cell (MEC) microenvironment includes stromal cells and extracellular matrix (ECM). Abundant evidence shows that the ECM and growth factors co-operate to regulate cell cycle progression, and that the ECM is altered in breast tumors. In particular, mammographically dense breast tissue is a significant risk factor for developing breast carcinomas. Dense breast tissue is associated with increased stromal collagen and epithelial cell content. In this article, we overview recent studies addressing the effects of ECM composition on the breast cancer cell cycle. Although the normal breast ECM keeps the MEC cycle in check, the ECM remodeling associated with breast cancer positively regulates the MEC cycle. ECM effects on the downstream biochemical and mechanosignaling pathways in both normal and tumorigenic MECs will be reviewed.
A procedure for evaluating portable heart monitors

Portable heart rate monitors are potentially useful for regulating exercise intensity. This paper describes procedures to evaluate these devices while subjects are resting, cycling, or running. Of the five monitors tested, all performed reasonably well while subjects were at rest; however, with one exception, performance deteriorated when the monitors were used during exercise. Even so, depending on the level of accuracy required, some of the monitors remained useful during cycling, but only one monitor was consistently accurate while subjects were running. This evidence indicates that, before selecting a particular monitor, potential users of such equipment should carefully consider many things, including the circumstances under which the equipment will be employed. The procedures reported in this paper should be generally useful in evaluating the performance of a variety of devices for monitoring heart rate.
Analysis of the Turkish broiler sector: The case of price competition

Abstract Production technology used in the Turkish broiler sector is well developed. Eighty percent of production is mostly carried out at integrated facilities, using internationally competitive techniques that are employed in developed countries. Broiler slaughter capacities are 15 000–17 000 units/h. The increase in the concentration ratio of top four firms (CR4) in the broiler sector has caused doubts about the competitiveness. According to 2004 data, the top 20 firms produce 84% of the total production and CR4 is 38.7%. In this study, a differentiated product oligopoly model has been applied to the Turkish broiler sector, and the price competition from 1998 to 2004 has been analysed. The top five firms, which have the highest competitive power and which are the only firms that meet the European Standards and are exporting broiler meat to the EU countries, have been included in the analysis. The results show that these firms have elastic demand and positive price cost margin.
Hydrological controls on dissolved organic carbon during snowmelt in the Snake River near Montezuma, Colorado

A quantitative understanding of the factors controlling the variation of dissolved organic carbon (DOC) in headwater streams is of scientific concern for at least two reasons. First, quantifying the overall carbon budgets of lotic systems is needed for a fundamental understanding of these systems. Second, DOC interacts strongly with other dissolved substances (heavy metals in particular) and plays an important role in the transport of contaminants. In the Snake River near Montezuma, Colorado, measurements of DOC from 1980 to 1986 show rapid decreases in concentration from a peak very early in the snowmelt period. Peak DOC concentrations occur approximately one month prior to peak discharge in the stream. The decline in DOC with time is approximately exponential, suggesting that a simple flushing mechanism can explain the response. We examined hydrological mechanisms to explain the observed variability of DOC in the Snake River by simulating the hydrological response of the catchment using TOPMODEL and routing the predicted flows through a simple model that accounted for temporal changes in DOC. Conceptually the DOC model represents a terrestrial (soil) reservoir in which DOC builds up during low flow periods and is flushed out by infiltrating meltwaters. The model reproduces the main features of the observed variation in DOC in the Snake River and thus lays the foundation for quantitatively linking hydrological processes with carbon cycling through upland catchments. Model results imply that a significant fraction of the soils in the Snake River catchment contribute DOC to the stream during peak discharge. Our work represents one of the first attempts to quantitatively describe the hydrological controls on DOC dynamics in a headwater stream. These controls are studied through the model by imposing mass balance constraints on both the flux of water through the various DOC source areas and the amount of DOC that can accumulate in these areas.
Radiation modeling using the Uintah heterogeneous CPU/GPU runtime system

The Uintah Computational Framework was developed to provide an environment for solving fluid-structure interaction problems on structured adaptive grids on large-scale, long-running, data-intensive problems. Uintah uses a combination of fluid-flow solvers and particle-based methods for solids, together with a novel asynchronou task-based approach with fully automated load balancing. Uintah demonstrates excellent weak and strong scalability at full machine capacity on XSEDE resources such as Ranger and Kraken, and through the use of a hybrid memory approach based on a combination of MPI and Pthreads, Uintah now runs on up to 262k cores on the DOE Jaguar system. In order to extend Uintah to heterogeneous systems, with ever-increasing CPU core counts and additional on-node GPUs, a new dynamic CPU-GPU task scheduler is designed and evaluated in this study. This new scheduler enables Uintah to fully exploit these architectures with support for asynchronous, out-of-order scheduling of both CPU and GPU computational tasks. A new runtime system has also been implemented with an added multi-stage queuing architecture for efficient scheduling of CPU and GPU tasks. This new runtime system automatically handles the details of asynchronous memory copies to and from the GPU and introduces a novel method of pre-fetching and preparing GPU memory prior to GPU task execution. In this study this new design is examined in the context of a developing, hierarchical GPU-based ray tracing radiation transport model that provides Uintah with additional capabilities for heat transfer and electromagnetic wave propagation. The capabilities of this new scheduler design are tested by running at large scale on the modern heterogeneous systems, Keeneland and TitanDev, with up to 360 and 960 GPUs respectively. On these systems, we demonstrate significant speedups per GPU against a standard CPU core for our radiation problem.
Temperament and Adolescent Substance Use: A Transactional Analysis of Emerging Self-Control

Presented is a conceptual framework linking the construct of temperament with environmental factors that covary with the onset and escalation of substance use. We propose that transactions between temperament characteristics of the child in family and peer contexts influence the development of self-control ability, a mediating factor for onset and possible transition to abuse in later adolescence. Risk-promoting dimensions may influence the emergence of self-control by amplifying relationship processes that detract from competence development. Emergence of good self-control can serve as a resilience factor and is linked with health-promoting cognitions. We also suggest that temperament and self-control moderate links between parenting, peer associations, and substance use. Implications of the transactional model for clinical intervention and research are discussed.
Radiation treatment in older patients: a framework for clinical decision making.

In older patients, radiation treatment plays a vital role in curative and palliative cancer therapy. Radiation treatment recommendations should be informed by a comprehensive, personalized risk-benefit assessment that evaluates treatment efficacy and toxicity. We review several clinical factors that distinctly affect efficacy and toxicity of radiation treatment in older patients. First, locoregional tumor behavior may be more indolent in older patients for some disease sites but more aggressive for other sites. Assessment of expected locoregional relapse risk informs the magnitude and timeframe of expected radiation treatment benefits. Second, assessment of the competing cancer versus noncancer mortality and morbidity risks contextualizes cancer treatment priorities holistically within patients' entire spectrum and time course of health needs. Third, assessment of functional reserve helps predict patients' acute treatment tolerance, differentiating those patients who are unlikely to benefit from treatment...
The SIRTF mission

This paper describes the status of NASA's Space Infrared Telescope Facility (SIRTF) program. SIRTF will be a cryogenically cooled observatory for infrared astronomy from space and is planned for launch early in the next decade. We discuss a newly modified baseline SIRTF mission and review the state of the detector technology which will provide the heart of SIRTF's scientific advances.
An Analysis of the Published Mineral Resource Estimates of the Haji-Gak Iron Deposit, Afghanistan

The Haji-Gak iron deposit of eastern Bamyan Province, eastern Afghanistan, was studied extensively and resource calculations were made in the 1960s by Afghan and Russian geologists. Recalculation of the resource estimates verifies the original estimates for categories A (in-place resources known in detail), B (in-place resources known in moderate detail), and C1 (in-place resources estimated on sparse data), totaling 110.8 Mt, or about 6% of the resources as being supportable for the methods used in the 1960s. C2 (based on a loose exploration grid with little data) resources are based on one ore grade from one drill hole, and P2 (prognosis) resources are based on field observations, field measurements, and an ore grade derived from averaging grades from three better sampled ore bodies. C2 and P2 resources are 1,659.1 Mt or about 94% of the total resources in the deposit. The vast P2 resources have not been drilled or sampled to confirm their extent or quality. The purpose of this article is to independently evaluate the resources of the Haji-Gak iron deposit by using the available geologic and mineral resource information including geologic maps and cross sections, sampling data, and the analog-estimating techniques of the 1960s to determine the size and tenor of the deposit.
Training, Technological Changes, and Displacement

By matching industry/occupation data on training to displaced worker data from the Current Population Surveys, this paper analyzes why many older workers were displaced by technological changes in the 1990s, and why these workers incurred large earnings losses. When technological changes depreciate the existing stock of firm-specific human capital, older workers who receive higher wages from the sharing arrangement of the returns to investment in firm-specific human capital are dismissed as firms find it unprofitable to retain them. These displaced workers have higher predisplacement wages with steeper wage-tenure profiles, and hence incur larger earnings losses after displacement than other displaced workers.
Mapping Highly Congested Proton NMR Spin Systems of Natural Products Using Two-Dimensional Proton Double Quantum Coherence

Abstract Highly congested terpenoid proton NMR spectra are generally intractable to detailed analysis and assignment. Analyses of the proton-proton connectivity networks in such spectra are, however, possible using the proton double quantum coherence two-dimensional NMR experiment. Natural cycloseychellene, which contains resonances for twenty four protons within a 1.2 ppm wide region is used as an example to demonstrate this technique.
Abstract 3160: A redox-sensitive PEST sequence regulates Nrf2 degradation through proteasome pathway

Nrf2 transcription factor plays the pivotal role in protection against oxidative stress and chemical carcinogens by inducing a group of antioxidant/detoxification enzymes. Control of Nrf2 degradation is believed to be one of the major mechanisms in regulation of Nrf2-dependent gene expression. Here we report identification of a redox sensitive PEST sequence that targets Nrf2 protein to degradation through proteasome pathway. The PEST sequence locates between amino acids 332 and 359 in human Nrf2. Deletion of this sequence not only prolonged Nrf2 half-life, but also greatly enhanced Nrf2 transactivation function. Insertion of this sequence to the C-terminus of green fluorescence protein (GFP) caused rapid degradation of the fusion protein. Although deletion or insertion of the PEST sequence did not change the status of protein ubiquitination, its dependent protein degradation was sensitive to proteasome inhibition. Interestingly, PEST-mediated protein degradation was also sensitive to oxidant treatments. More over, delivery of a synthetic peptide that mimics PEST sequence caused accumulation of Nrf2 protein and activated downstream genes. Thus, we conclude that, in addition to a previously identified Keap1 pathway, Nrf2 is also actively degraded through a PEST sequence under homeostatic condition. Targeting this sequence would offer a novel approach for activation of Nrf2-dependent protective mechanisms. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3160.
Focal points and pricing behavior: Results in an experimental oligopoly

The problem of describing and predicting oligopoly outcomes is an old one in economics. It is well known that some real world oligopolies continue for long periods of time with Cournot-like price structures, while others attain price and output levels approximating that of a monopolist. A number of authors have suggested that an understanding of these different results may be aided by a concern for the mechanisms of tacit communication in oligopoly (6, 7, 13, 14). By these tacit communication mechanisms, oligo-polists may convey information regarding their expectations and intents (11, pp. 179–182). In this article, the use of focal point pricing as a tacit communication mechanism is investigated in the context of an experimental oligopoly.
Differential regulation of cAMP by endogenous versus transfected fornylpeptide chemoattractant receptors: Implications for Gi-coupled receptor signaling

Endogenous neutrophil formylpeptide receptors do not inhibit adenylylcyclase activation. The ability of a cloned and transfected human formylpeptide receptor to mediate the inhibition of adenylylcyclase was assessed in the human embryonic kidney 293 TSA cell line. Inclusion of 1 microM fMetLeuPhe resulted in a ca. 50% inhibition of isoproterenol-stimulated cAMP in transfected cells. Activation of adenylylcyclase by isoproterenol was inhibited ca. 30% by fMetLeuPhe in membranes prepared from transfected cells but not in membranes prepared from neutrophils. Prior treatment of transfected cells with pertussis toxin abrogated the inhibitory effect of fMetLeuPhe. These data indicate that factors in addition to the primary structure of the formylpeptide receptor govern its transductional activities.
MRI demonstration of hypertrophic articular cartilage repair in osteoarthritis

Transection of the anterior cruciate ligament in the dog produces changes in the unstable joint typical of osteoarthritis, although full-thickness cartilage ulceration is rare. Information concerning the late fate of the cartilage after transection is meager. In the present study magnetic resonance imaging (MRI) was used to evaluate cartilage abnormalities 3 years after transection. Plain radiographs of the osteoarthritic and contralateral knees were obtained serially. MRI was performed 3 years after anterior cruciate ligament transection, at which time all three animals exhibited knee instability. Radiographs of the osteoarthritic knees showed osteophytes and subchondral sclerosis with progression between 2 and 3 years. On MRI, articular cartilage margins in the knee were indistinct, and the cartilage was thicker than that in the contralateral knee (maximum difference = 2.7 mm). This increase in thickness is consistent with biochemical data from dogs killed up to 64 weeks after creation of knee instability, which showed marked increased in cartilage bulk and in proteoglycan synthesis and concentration. The findings emphasize that increased matrix synthesis after anterior cruciate ligament transection leads to functional cartilage repair sustained even in the presence of persistent alteration of joint mechanics.
Graphite first wall thermal performance in ICF reactor

Graphite has been considered as a candidate material for the first wall in ICF reactors. This paper shows the thermal performance of the graphite first wall (GFW) in the 0.25 μm laser driven materials test reactor SIRIUS-M. The first wall temperature response due to the X-rays, reflected laser light, and ions that emanate from the 13.4 MJ yield target was calculated for dry GFWs which were either unprotected or gas protected. Evaporation rates and thermal stresses were calculated and minimum radii were chosen for both cases. It was found that the reflected laser light from the target produces the highest temperature rise in the gas protected GFW. If 10% of the laser light is reflected from the target and the reflectivity of graphite is 50%, the maximum thermal stress in the GFW is about 90% of the compressive strength for a 2 m radius cavity. Therefore, the viability of the first wall design depends critically on the laser light reflected from the target. the graphite reflectivity and the strength of the graphite.
A ``gel'' model for coal

Coal is a sedimentary, organic “rock” which is almost never in a state of thermal equilibrium. Because of its importance, the thermal properties of this ill-characterized substance are of great interest. Recent work has shown that coal has many of the characteristics of a gel-type structure. We have made this observation the basis for a model study of the thermal properties of a gel system, using the equation-of-motion method to determine the density of states for the system and, thereby, its heat capacity. This model has one of the essential features of a model of coal, namely, a porous structure. With a hexagonal close-packed lattice as the basis for our gel, we have calculated the frequency spectrum for several particle densities. The disorder in the system has a marked effect on the frequency spectrum, shifting a larger number of modes from high to low frequencies. Also, for a gel with 3% vacancies, and in-plane, out-of-plane bond strengths at the ratio 2∶ 1, there is a further shift to lower frequencies and the two-peaked spectrum expected for such an anisotropic structure develops. The heat capacity is affected only at low temperatures. We conclude that the gel model provides a satisfactory basis for development as a model of coal.
Mare Balticum and Balticum

(1979). Mare Balticum and Balticum. Journal of Baltic Studies: Vol. 10, No. 2, pp. 135-147.
Water year 2004: Western water managers feel the heat

This spring, a rare combination of exceptionally warm temperatures and near-record lack of precipitation in the western United States caused a rapid change in hydrologic conditions and an unexpectedly early onset of spring conditions. With much of the western U.S. already in its fifth year of drought, an above-average western snowpack on 1 March 2004 provided hope for much-needed abundant runoff. Unfortunately snowmelt began far earlier than anticipated, resulting in dramatic declines in seasonal spring-summer streamflow forecasts as the month proceeded, declines more rapid by some measures than ever before in the past 75 years. With reservoirs near historic lows, many water users have been hard pressed to deal with the continuing drought.
Representation and Process in Reasoning about Logical Relationships

Summary According to a popular conception of reasoning, the thinker first mentally represents given information and then processes the resulting representations. It is commonly assumed, at least implicitly, that difficulty of the representation step is solely a function of facility with the form and content of the information to be represented, while difficulty of the processing step is solely a function of facility with the operation(s) necessary to meet the task requirements. Within this two-step information processing model, form/ content variables and task requirements should thus have an additive effect on problem difficulty. To test this prediction, 72 male students in grades 7, 10, and college were presented with two tasks involving the same set of logical propositions. The effects of both form and content were found to be a function of task. These interactions seem to contradict the notion that form/ content and task variables relate exclusively to different steps in reasoning. Theoretical implica...
Gaps in DNA synthesized by ultraviolet light-irradiated WI38 human cells.

Abstract DNA replication in ultraviolet-irradiated human cells was examined by treatment of the extracted DNA with a single-strand specific endonuclease from Neurospora crassa . WI38 cells were uniformly labeled with 32 P i for two generations before irradiation and then labeled with [ 3 H]thymidine after irradiation. The isolated DNA was sedimented in neutral sucrose gradients after incubation with the endonuclease. The endonuclease treatment had no effect on the sedimentation profiles of either [ 32 P]DNA or [ 3 H]DNA from unirradiated control cultures. The endonuclease treatment also did not significantly alter the profile of [ 32 P]DNA from irradiated cultures but did introduce breaks in the 3 H pulse-labeled DNA synthesized after irradiation. These results indicate that DNA synthesis after ultraviolet irradiation proceeds in such fashion that gaps are formed along the newly made strand, leaving regions of single strandness in template DNA. As replication proceeds these gaps disappear and 2 h after irradiation (100–250 ergs/mm 2 ) they are barely detectable by the endonuclease assay.
The effect of surface alloying on the plastic deformation behavior of copper

Abstract The effect of surface-alloying on the mechanical properties and dislocation arrangements in high-purity copper single crystals was investigated. An alloyed region to 0.4–2 μ from the surface was created by limited diffusion of a given thickness of either nickel or gold surface films. Various surface concentration gradients resulted, with a corresponding gradient in elastic constants and lattice parameter. The critical resolved shear stress was increased for all the surface treatments. The maximum strength increase was about three times that of a pure copper crystal. Corresponding changes were also observed for the rate of work-hardening and extent of stage I deformation. In all cases, the surface-strengthening effects could be related to the surface concentration gradient. Several factors influencing the mechanical properties are operative, which include image forces, solid-solution hardening effects and interfacial misfit dislocation networks. An assessment of these contributors to surface-strengthening effects revealed solid-solution hardening as the most likely source, for the magnitude of the compositional gradients obtained in these experiments. Misfit dislocation networks were observed in the case of a gold solute, but were not associated with appreciable strengthening effects. It is expected that, for more severe surface concentration gradients than obtained in the present work, misfit dislocation networks would assume an importance equivalent to solid-solution hardening, at least for a similar range of lattice parameter mismatch.
Current spreading in apertured vertical-cavity lasers

Scaling of the threshold current density in apertured vertical cavity lasers is limited by scattering losses, current spreading, and carrier diffusion. We consider the contributions of all three effects, but focus on current spreading. We analyze a vertical cavity laser (VCL) with low scattering losses so the scaling of the threshold current density is dominated by current spreading under the aperture. We show that a simple analytic estimate (appropriate for circular geometry) for the increase in threshold matches experimental data extremely well without any fitting parameters. One can also conveniently apply the estimate of current spreading to VCLs with double apertures or multiple layers of different resistivities. We also show that current spreading should only negligibly reduce the differential efficiency as implied by experiment.
Evaluation of the Relationship between Heart Rate and Ventilation for Epidemiologic Studies

Estimation of pulmonary exposure and dose in air pollution epidemiology has been impaired by the lack of methods for directly measuring ventilation in ambulatory subjects. Heart-rate monitoring offers an approach to estimate ventilation by using ventilation-on-heart-rate (VE-HR) regressions established during exercise testing to estimate ventilation in the field. Conventional methods and protocols for testing were used to evaluate the relationship between VE and HR during three tasks: (1) exercising on a cycle ergometer, (2) lifting, and (3) vacuuming. The relationship between VE and HR was curvilinear and was best fit with linear regression models, using a natural log transformation of VE. Considerable interindividual variability in slopes and intercepts was observed across all types of exercise tests. The variability about the fitted regression lines for individual subjects was minimal; for example, individual R2 values for the maximum exercise test on 15 men ranged from 0.90 to 0.99 (mean = 0.97). The regression slopes established during upper-body exercise were greater by approximately 30%, relative to those derived in lower-body exercise (paired t test, p < .001). However, VE-HR regression slopes derived from tests in which progressively increasing workloads were used were comparable to those obtained during variable and nonprogressive protocols. These findings indicate that predictive accuracy is maximized by deriving VE-HR regressions for individual subjects and for both lower- and upper-body activities.
Calcium addition at the Hubbard Brook Experimental Forest increases the capacity for stress tolerance and carbon capture in red spruce (Picea rubens) trees during the cold season

Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable of photo- synthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology of red spruce during the cold season, we measured concentrations of foliar polyamines and free amino acids (putative stress- protection compounds), chlorophyll (a key photosystem component), and sapwood area (a proxy for foliar bio- mass), for trees in Ca-addition (CaSiO3 added) and Ca- depleted (reference) watersheds at the Hubbard Brook Experimental Forest (NH, USA). Ca-addition increased concentrations of the amino acids alanine and c-aminobu- tyric acid (GABA) and the polyamines putrescine (Put) and spermidine (Spd) in November, and Put in February rela- tive to foliage from the reference watershed. Consistent with increased stress protection, foliage from the Ca- addition watershed had higher total chlorophyll and chlo- rophyll a concentrations in February than foliage from the reference watershed. In contrast, foliage from the reference watershed had significantly lower glutamic acid (Glu) and higher alanine (Ala) concentrations in February than foli- age from the Ca-addition watershed. Imbalances in Ala:Glu have been attributed to cold sensitivity or damage in other species. In addition to concentration-based differences in foliar compounds, trees from the Ca-addition watershed had higher estimated levels of foliar biomass than trees from the reference watershed. Our findings suggest that Ca- addition increased the stress tolerance and productive capacity of red spruce foliage during the cold season, and resulted in greater crown mass compared to trees growing on untreated soils.
Duration of colonization with methicillin-resistant Staphylococcus aureus among patients in the intensive care unit: implications for intervention.

OBJECTIVES To determine the duration of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection before entry and during hospitalization in the intensive care unit (ICU) and the characteristics of patients who tested positive for MRSA. DESIGN Prospective observational cohort survey. SETTING A combined medical and coronary care ICU with 16 single-bed rooms in a 427-bed tertiary care Veteran Affairs Medical Center. PATIENTS A total of 720 ICU patients associated with 845 ICU admissions were followed up for the detection of MRSA from January 13, 2003, to October 12, 2003. MRSA colonization was detected in patients by using active surveillance cultures (ASCs) of nasal swab specimens obtained within 48 hours of ICU entry and 3 times weekly thereafter. The duration of colonization during ICU stay and before ICU entry was calculated after a review of surveillance culture results, clinical culture results, and medical history. RESULTS Ninety-three (11.0%) of 845 ICU admissions involved patients who were colonized with MRSA at the time of ICU entry, and 21 admissions (2.5%) involved patients who acquired MRSA during ICU stay. ASCs were positive for MRSA in 84 (73.6%) of the 114 admissions associated with MRSA positivity and were the sole means of identifying MRSA in 50 cases (43.8%). More than half of the MRSA-associated admissions involved patients who were transferred from hospital wards. The total bed-days of care for 38 admissions involving patients who tested positive for MRSA before ICU entry (1131 days) was nearly 20% higher than the total bed-days of care for all admissions associated with MRSA positivity (970 days). Admissions involving MRSA-positive patients were associated with a longer length of hospitalization before ICU entry (P < .001), longer length of ICU stay (P < .001), longer overall length of hospitalization (P < .001), and greater inpatient mortality than admissions involving MRSA-negative patients (P < .001). A total of 22.8% of all bed-care days were dedicated to MRSA-positive patients in the ICU, and 55 (48.2%) of 114 admissions associated with MRSA positivity involved patients who were colonized for the duration of their ICU stay. CONCLUSIONS In our unit, ASCs were an effective means to identify MRSA colonization among patients admitted to the ICU. Unfortunately, the majority of identified patients had long durations of stay in our own hospital before ICU entry, with prolonged MRSA colonization. Enhanced efforts to control MRSA will have to account for the prevalence of MRSA within hospital wards and to direct control efforts at these patients in the future.