cssi/SciSciGPT-SciSciNet huggingface dataset:
Carbon emissions from a temperate coastal peatland wildfire: contributions from natural plant communities and organic soils.

BACKGROUND One of the scientific challenges of understanding climate change has been determining the important drivers and metrics of global carbon (C) emissions and C cycling in tropical, subtropical, boreal, subarctic, and temperate peatlands. Peatlands account for 3% of global land cover, yet contain a major reservoir of 550 gigatons (Gt) of soil C, and serve as C sinks for 0.37 Gt of carbon dioxide (CO2) a year. In the United States, temperate peatlands are estimated to store 455 petagrams of C (PgC). There has been increasing interest in the role of wildfires in C cycling and altering peatlands from C sinks to major C sources. We estimated above- and below-ground C emissions from the Pains Bay Fire, a long-duration wildfire (112 days; 18,329 ha) that burned a coastal peatland in eastern North Carolina, USA. RESULTS Soil C emissions were estimated from pre- and post-burn Light Detection and Ranging (LIDAR) soil elevation data, soils series and C content mapping, remotely sensed soil burn severity, and post-burn field surveys of soil elevation. Total above-ground C emissions from the fire were 2,89,579 t C and 214 t C ha-1 for the 10 vegetation associations within the burn area perimeter. Above-ground sources of C emissions were comprised of litter (69,656 t C), shrub (1,68,983 t C), and foliage (50,940 t C). Total mean below-ground C emissions were 5,237,521 t C, and ranged from 2,630,529 to 8,287,900 t C, depending on organic matter content of different soil horizons within each of the 7 soil series. The mean below-ground C emissions within the burn area were 1,595.6 t C ha-1 and ranged from 629.3 to 2511.3 t C ha-1. CONCLUSIONS In contrast to undisturbed temperate peatlands, human induced disturbances of the natural elevation gradient of the peatland has resulted in increased heterogeneity of floristic variation and assemblages that are a product of the spatial and temporal patterns of the water table level and the surface wetness across peatlands. Human induced changes in surface hydrology and land use influenced the fuel characteristics of natural vegetation and associated soils, thus influencing wildfire risk, behavior, and the resulting C emissions.
CG Dinucleotide Removal in Bioluminescent and Fluorescent Reporters Improves HIV-1 Replication and Reporter Gene Expression for Dual Imaging in Humanized Mice.

Visualizing the transmission and dissemination of human immunodeficiency virus type 1 (HIV-1) in real time in humanized mouse models is a robust tool to investigate viral replication during treatments and in tissue reservoirs. However, the stability and expression of HIV-1 reporter genes are obstacles for long-term serial imaging in vivo. Two replication-competent CCR5-tropic HIV-1 reporter constructs were created that encode either nanoluciferase (nLuc) or a near-infrared fluorescent protein (iRFP) upstream of nef. HIV-1 reporter virus replication and reporter gene expression was measured in cell culture and in humanized mice. While reporter gene expression in vivo correlated initially with plasma viremia, expression decreased after 4 to 5 weeks despite high plasma viremia. The reporter genes were codon optimized to remove cytosine/guanine (CG) dinucleotides, and new CO-nLuc and CO-iRFP viruses were reconstructed. Removal of CG dinucleotides in HIV-1 reporter viruses improved replication in vitro and reporter expression in vivo and ex vivo. Both codon-optimized reporter viruses could be visualized during coinfection and in vivo reporter gene expression during treatment failure preceded detection of plasma viremia. While the dynamic range of CO-iRFP HIV-1 was lower than that of CO-nLuc HIV-1, both viruses could have utility in studying and visualizing HIV-1 infection in humanized mice. IMPORTANCE Animal models are important for studying HIV-1 pathogenesis and treatments. We developed two viruses each encoding a reporter gene that can be expressed in cells after infection. This study shows that HIV-1 infection can be visualized by noninvasive, whole-body imaging in mice with human immune cells over time by reporter expression. We improved reporter expression to reflect HIV-1 replication and showed that two viral variants can be tracked over time in the same animal and can predict failure of antiretroviral therapy to suppress virus.
Passive acoustic monitoring of river dolphin (Inia geoffrensis and Sotalia fluviatilis) presence: : A comparison between waters near the city of Iquitos and within the Pacaya-Samiria National Reserve

All river dolphin species are in decline as a direct result of intensified anthropogenic activity along river systems. In South America, the size and geographical complexity of their range pose a challenge to status assessment. Passive acoustic monitoring offers a cost-effective, scalable, and readily standardized method for determining species distribution and can augment the spatiotemporal coverage of visual survey efforts currently underway. A passive acoustic survey of dolphin presence was conducted in two areas of the Amazon River subject to different degrees of human use; the inland port city Iquitos and the Pacaya-Samiria National Reserve, in Peru. Surveys were based on acoustic detection of biosonar activity. Recorders were distributed at 17 sites along 61 linear km of river habitat for durations of 46 to 148 h. Dolphin presence was 45% lower near the city than in the reserve. This study demonstrates the efficacy of acoustic monitoring as a method for testing dolphin redistribution and/or decline hypotheses in the context of anthropogenic development. The methods are applicable to continuous future monitoring and status assessment of river dolphins in South America as well as in Asia.
Principles of antibiotic treatment of gram-negative bacteremia

Patients with gram-negative bacteremia studied between 1951–1958 (173 patients) and 1965–1974 (612 patients) were carefully evaluated to delineate critical determinants of outcome. Severity of the host's underlying disease was the major factor influencing outcome in both series. Early appropriate antibiotic therapy was associated with significant reductions in both fatality rates and the frequency of development of shock. Appropriate antibiotic therapy was also associated with a significant reduction in fatality rates even if initiated after the onset of shock. Most individual antimicrobial agents appeared to be of comparable efficacy provided the infecting organism was susceptible. Combinations of antibiotics could not be demonstrated to be more effective than single agents.
Sexual and gender minority disproportionality and disparities in child welfare: A population-based study

Abstract Empirical research is needed to support ongoing efforts to improve services for sexual and gender minority youth in foster care. Further, data on the presence of sexual and gender minority youth within the child welfare system are needed to encourage counties that have not yet begun to engage in any efforts to address the unique needs and barriers to permanency for these youth. The current study reports on the findings of the Los Angeles Foster Youth Survey (LAFYS) which was designed to assess the proportion of youth placed in the Los Angeles County public child welfare system who are LGBTQ and to examine their experiences in communities, schools, and foster care. Findings indicate that approximately 19% of Los Angeles foster youth are LGBTQ. This proportion of youth is significantly higher than estimates of adolescent and young adult sexual and gender minority identification rates in the general population. Further, analyses also indicate that sexual and gender minority youth in this study are less satisfied with their child welfare system experience, are more likely to experience homelessness, are moved around to more placements, and are experiencing higher levels of emotional distress compared to their non-LGBTQ counterparts.
Racialized Policing: A Study of Three Neighborhoods

One of the most controversial issues in policing concerns allegations of racial bias. This article examines citizens' perceptions of racialized policing in three neighborhoods in Washington, D.C., that vary by racial composition and class position: a middle-class white community, a middle-class black community, and a lower-class black community. In-depth interviews examined residents' perceptions of differential police treatment of individual blacks and whites in Washington and disparate police practices in black and white neighborhoods. Findings indicate, first, that there is substantial agreement across the communities in the belief that police treat blacks and whites differerently; and secondly, there is racial variation in respondents' explanations for racial disparities. On the question of residents' assessments of police relations with their own community relative to other-race communities, a neighborhood difference is found, with the black middle-class neighborhood standing apart from the other two neighborhoods.
Linking cardiometabolic disorders to sporadic Alzheimer’s disease: a perspective on potential mechanisms and mediators

There is increasing evidence that the incidence of Alzheimer's disease (AD) is significantly influenced by cardiovascular risk factors in association with a cluster of metabolic diseases including diabetes and atherosclerosis. The shared risk is also reflected in the dietary and lifestyle links to both metabolic disorders and AD-type cognitive dysfunction. Recent studies with genetic and diet-induced animal models have begun to illuminate convergent mechanisms and mediators between these two categories of disease conditions with distinct tissue-specific pathologies. Although it is clear that peripheral inflammation and insulin resistance are central to the pathogenesis of the disorders of metabolic syndrome, it seems that the same mechanisms are also in play across the blood-brain barrier that lead to AD-like molecular and cognitive changes. This review highlights these convergent mechanisms and discusses the role of cerebrovascular dysfunction as a conduit to brain emergence of these pathogenic processes that might also represent future therapeutic targets in AD in common with metabolic disorders.
New agents with potential for radiation enhancement

During 1996, an impressive number of new antineoplastic agents were approved by the United States Food and Drug Administration. In addition, advances in molecular biology are providing information about new targets against which to develop new agents. In this discussion, we will review some exciting new agents with previously documented antitumor activity that are excellent candidates for combining with radiation therapy. These agents include LY231514, a thymidylate synthase inhibitor that also interacts with dihydrofolate reductase and inhibits glycinamide ribonucleotide transformylase, a key enzyme in the de novo purine pathway. This drug has been evaluated in phase I studies and may possess radiosensitizing activity. Capecitabine is a 5-fluorouracil prodrug that is activated primarily in tumor tissue and is orally active. ONYX-015 is an attenuated adenovirus that only replicates in cells that have a p53-genetic mutation. Telomerase inhibitors also may be effective in preventing tumor recurrence following definitive radiation therapy. Several other agents are on the horizon and show promise as radiation sensitizers, though clinical data on the combinations are not yet available.
The Elusive Connection

In his monograph Electroacoustics, F.V. HUNT (1954) described the carbon microphone as "the only 'bad connection' tolerated in the telephone system". This whimsical comment was, of course, inspired by the unique electrical properties of that remarkable transducer. A broader view, encompassing the acoustical as well as the electrical elements of the system, would surely compel us to recognize the earphone, another essential element of the telephone system, as a connection of equally questionable quality. It was indeed this doubtful connection, lying at the heart of audiometric measurements, which first prompted my colleagues and I in Ottawa to enquire about the acoustics of the external ear many years ago. It seemed then, as now, that despite the remarkable advances in electromechanical transduction since the days of Alexander Graham Bell, the coupling between earphones and ears still rested on a very flimsy acoustical foundation. We soon found that there were questions concerning the external ear which were larger than the technological artifacts that had started us on our journey and it is to these larger questions that my title refers. The "elusive connection", then, is associated with the external ear but really embraces the entire transmission path between the sound source, which may be near the ear or in the far field, and the oval window of the cochlea which is the input terminal of the inner ear. The questions which arise fall under at least five headings: (i) Anatomy and function: How does the external ear work? What are the functions of its various components? How is it coupled to the middle ear? What parameters best define its performance? (ii) Reception efficiency: How well does the external ear collect sound energy? How well is that energy transmitted to the inner ear? (iii) Sound localization: To what extent are we able to localize sound sources away from the horizontal plane especially sources lying in the symmetry plane of the head? What localization tasks can we perform with a single ear? What are the relevant auditory cues? (iv) Space perception: Under what circumstances and how well do we externalize sound when listening under artificial conditions such as those arising with earphones? (v) Measurement techniques: How should we specify and measure acoustic stimuli? As we shall see, some of these questions were raised more than one hundred years ago but still lack precise answers.
NEW OPPORTUNITIES FOR FUTURE SMALL CIVIL TURBINE ENGINES: OVERVIEWING THE GATE STUDIES

This paper presents an overview of four independent studies that explore the opportunities for future General Aviation Turbine Engines (GATE) in the 150-1000 SHP class. Detroit Diesel Allison, Garrett/AiResearch, Teledyne CAE, and Williams Research participated along with several airframers. These studies forecasted the potential impact of advanced technology turbine engines in the post-1988 market, identified important aircraft and missions, desirable engine sizes, engine performance and cost goals. Parametric evaluations of various engine cycles, configurations, design features, and advanced technology elements defined baseline conceptual engines for each of the important missions identified by the market analysis. Both fixed-wing and helicopter aircraft, and turboshaft, turboprop, and turbofan engines were considered. All four companies predicted sizable performance gains (e.g., 20% SFC decrease), and three predicted large engine cost reductions of sufficient magnitude to challenge the reciprocating engine in the 300-500 SHP class. Key technology areas were recommended for NASA support in order to realize these improvements.
A fully parallel learning neural network chip for real-time control

Presents a parallel learning neural network chip, which is used to perform real-time output feedback control on a nonlinear dynamic plant. The controlled plant is a simulated unstable combustion process. Neural networks provide an adaptive sub-optimal control that does not need any prior knowledge of the system. In addition, the hardware neural network presented here utilizes parallelism to achieve speed independent of the size of the network enabling real-time control. On-chip learning ability allows the hardware neural network to learn online as the plant is running and the plant parameters are changing. Also described is the experimental setup used to obtain the results.
A high-efficiency miniaturized SiGe Ku-band balanced frequency doubler

A monolithic SiGe balanced frequency doubler has been designed and measured for Ku-band application. The circuit operates with a 2 V supply voltage and consumes only 28 mW of DC power when the doubler is biased close to class B operation, with an input power of 1.5 dBm. An output power of 5-6 dBm is obtained from 15.4-18 GHz and the fundamental suppression is better than 25 dB. It has a high power added efficiency (PAE) of 9.2% and occupies only 700/spl times/350 /spl mu/m/sup 2/ of chip area.
Combining rule-based and neural-network approaches in the fusion of range and intensity signals

This paper exposes our approach to Sensor/Data Fusion through a prototype system developed for feasibility study and experimentation. System specifications include the fusion of data from multiple sensory modalities, processing in layers of abstraction, integration of qualitative and quantitative information processing, combination of alternative processing paths, and capabilities for learning. The domain selected is that of fusing a light intensity signal with a registered range signal. The system goal is to determine the existence and location of edge patterns; these correspond to occluding edges, surface orientation change edges, and edges denoting reflectance differences. The system combines two alternative processing paths, a feature-layer fusion process which uses classification rules, with a signal-layer fusion process which utilizes a Radial Basis Functions neural network. While the former process exploits predefined rules, the latter is able to learn from examples. Experiments show that, while any of the two alternative approaches can be invoked, their combined utilization is able to improve system performance. >
Three-Dimensional Chaotic Mixing of Fluids in a Cylindrical Cavity

Three-dimensional chaotic mixing of Newtonian fluids in a previously uninvestigated cylindrical cavity was studied both experimentally and numerically for creeping flow conditions. Such mixing processes have practical application to the blending of viscous fluids, biological suspensions, or can be used as test beds to study waterborne pollutant formation. A mixing chamber was fabricated which consisted of a cylindrical glass cavity with independently rotating upper and lower circular disks. Fluid motion was revealed by digitizing successive video images of a small neutrally buoyant sphere placed into the mixing cavity and also by photographing dyed blobs. Experimental particle tracking studies were supplemented by numerical simulations. Phase-space trajectories, return maps, and Lyapunov exponents were used to characterize the mixing process and to confirm chaotic behavior.
Optimized Expression and Purification for High-Activity Preparations of Algal [FeFe]-Hydrogenase

Recombinant expression and purification of metallo-enzymes, including hydrogenases, at high-yields is challenging due to complex, and enzyme specific, post-translational maturation processes. Low fidelities of maturation result in preparations containing a significant fraction of inactive, apo-protein that are not suitable for biophysical or crystallographic studies. We describe the construction, overexpression and high-yield purification of a fusion protein consisting of the algal [2Fe2S]-ferredoxin PetF (Fd) and [FeFe]-hydrogenase HydA1. The maturation of Fd-HydA1 was optimized through improvements in culture conditions and media components used for expression. We also demonstrated that fusion of Fd to the N-terminus of HydA1, in comparison to the C-terminus, led to increased expression levels that were 4-fold higher. Together, these improvements led to enhanced HydA1 activity and improved yield after purification. The strong binding-affinity of Fd for DEAE allowed for two-step purification by ion exchange and StrepTactin affinity chromatography. In addition, the incorporation of a TEV protease site in the Fd-HydA1 linker allowed for the proteolytic removal of Fd after DEAE step, and purification of HydA1 alone by StrepTactin. In combination, this process resulted in HydA1 purification yields of 5 mg L{sup -1} of culture from E. coli with specific activities of 1000 U (U = 1 {micro}mol hydrogenmore » evolved mg{sup -1} min{sup -1}). The [FeFe]-hydrogenases are highly efficient enzymes and their catalytic sites provide model structures for synthetic efforts to develop robust hydrogen activation catalysts. In order to characterize their structure-function properties in greater detail, and to use hydrogenases for biotechnological applications, reliable methods for rapid, high-yield expression and purification are required.« less
Use of Tables of Percentage Points of Range and Studentized Range

A description is given of new tables, more extensive and more accurate than any previously published, of the percentage points of the range and of the studentized range, for samples from a normal population. The purpose of this paper is to call attention to these tables and to illustrate their use. The following examples of the use of the tables are given: (1) an application of the percentage points of the range to tests of hypotheses concerning the standard deviation of a normal population; (2) an application of the percentage points of the range to rejection of outliers; and (3) an application of the percentage points of the studentized range to multiple comparisons tests on means of samples from a normal population.
SU-GG-I-35: Geometric Accuracy of High Contrast Region Visualization On 4D X-Ray CT Imaging Using Sinogram Binning

Purpose: To assess geometric errors in delineating high‐contrast structures from 4DCT‐acquired images undergoing simulated motion of various amplitudes. The broader goal is to formulate margin‐design guidelines that account for imperfections in 4D target imaging for a range of tumor sizes and motion amplitudes. Method and Materials: Three spherical objects with different diameters were placed on a moving platform adjusted to provide sinusoidal, one‐dimensional motions of various excursions (range: 0.5–4 cm) along the longitudinal axis of a Philips Brilliance scanner. Repeated scans were performed for three pitch values (0.15, 0.11, 0.075). Sinogram data were sorted into 10 different breathing phase bins. In addition, time‐averaged and maximum intensity projection (MIP) image sets were reconstructed.Data analysis included qualitative inspection of the shape of scanned objects, comparisons of contoured volumes for the static and moving targets, and centroid motion assessment. Results: The accuracy of reconstructed objects generally improves with decreasing amplitude and pitch. For large excursions and phases intermediate between exhale and inhale, large deviations from the spherical shape are observed; amplitude and volume deviations are as large as 10 mm and 30%. The observed centroid excursion is always less than the actual bin midpoint excursion. Smaller pitch does not always guarantee better results. The MIP centroid lines up closely with the centroid from time‐averaged datasets, but its actual position is underestimated by 3–4 mm as well. There is a tendency for deviations to be larger for datasets reconstructed during inhalation. Conclusion: The accuracy of 4D‐acquired datasets depends on motion characteristics and protocol acquisition parameters. The evaluation of the associated uncertainties is necessary for a more accurate margin design during treatment planning when either one or multiple 4D‐derived datasets are used for treatment planning. More studies are required to investigate the clinical significance of such errors. Supported in part by NIH P01 CA116602.
Endothelial TNF Receptor 2 Induces IRF1 Transcription Factor-Dependent Interferon-β Autocrine Signaling to Promote Monocyte Recruitment

Endothelial-dependent mechanisms of mononuclear cell influx are not well understood. We showed that acute stimulation of murine microvascular endothelial cells expressing the tumor necrosis factor receptors TNFR1 and TNFR2 with the soluble cytokine TNF led to CXCR3 chemokine generation. The TNF receptors signaled through interferon regulatory factor-1 (IRF1) to induce interferon-β (IFN-β) and subsequent autocrine signaling via the type I IFN receptor and the transcription factor STAT1. Both TNFR2 and TNFR1 were required for IRF1-IFNβ signaling and, in human endothelial cells TNFR2 expression alone induced IFN-β signaling and monocyte recruitment. In vivo, TNFR1 was required for acute renal neutrophil and monocyte influx after systemic TNF treatment, whereas the TNFR2-IRF1-IFN-β autocrine loop was essential only for macrophage accumulation. In a chronic model of proliferative nephritis, IRF1 and renal-expressed TNFR2 were essential for sustained macrophage accumulation. Thus, our data identify a pathway in endothelial cells that selectively recruits monocytes during a TNF-induced inflammatory response.
Nicotine up-regulates expression of orexin and its receptors in rat brain.

Orexins are two recently discovered neuropeptides that can stimulate food intake. As the chronic use of tobacco typically leads to a reduction in body weight, it is of interest to determine whether nicotine, the major biologically active tobacco ingredient, has an effect on orexin metabolism in the brain. Using a semiquantitative RT-PCR technique, the levels of messenger RNA (mRNA) for prepro-orexin, orexin A (OX1-R) and orexin B (OX2-R) receptors were 20 ‐50% higher in rats receiving nicotine for 14 days at the level of 2‐ 4 mg/kgzday compared with rats receiving saline solvent alone. In animals treated with nicotine at 4 mg/kgzday, the expression levels of mRNA for prepro-orexin, OX1-R, and OX2-R were significantly higher compared with those in either the free-feeding control or pair-fed saline control rats. RIA data indicated that both orexin A and orexin B peptide levels were significantly elevated (45‐54%; P , 0.01) in the dorsomedial nucleus (DMH) of the nicotine-treated rats compared with either solvent-only or pair-fed controls. Additionally, orexin B was significantly elevated (83%; P , 0.01), over levels in both types of the control animals, in the paraventricular nucleus (PVN) region. In summary, we demonstrated that an inverse association between nicotine and food intake as well as body weight held with doses comparable to those consumed by average human smokers. Moreover, our data indicated that chronic exposure to nicotine can induce a long-term increase in the expression levels of prepro-orexin and their receptor mRNA in the rat hypothalamus and in the levels of orexin A in the DMH and orexin B in the DMH and PVN among the six hypothalamic regions that we examined. (Endocrinology 141: 3623‐3629, 2000)
Measurement of intraocular Pressure with a Flat Anterior Chamber

When a flat chamber develops in an eye after filtration surgery, management depends on whether the cause is excessive filtration or aqueous misdirection (ciliary block or malignant glaucoma). This diagnosis is often based on the intraocular pressure: low pressure in excessive filtration, high pressure in aqueous misdirection. To determine the accuracy of tonometry when the lens is in contact with the cornea, flat anterior chambers were created in 5 eyes obtained from an eye bank. The pressure in the vitreous cavity was raised and lowered with an infusion line and monitored with a pressure transducer. The intraocular pressure was estimated with a Goldmann applanation tonometer, a Pneumatonometer, and a Tono-pen. The readings poorly represented the actual pressure in the vitreous cavity. The error was 0 to 51 mmHg (mean, 12.8 mmHg) with the Goldmann tonometer, 0 to 33 mmHg (mean, 9.0 mmHg) with the Pneumatonometer, and 1 to 28 mmHg (mean, 13.5 mmHg) with the Tono-pen. Therefore, in the face of a flat anterior chamber, pressure measurements made on the cornea cannot be relied on to distinguish excessive filtration from aqueous misdirection.
The Effect of a Magnetic Field on Electrons in a Periodic Potential

A theorem due to Wannier for treating the motion of electrons in a perturbed periodic field is generalized to include the effect of a slowly varying magnetic field. It is shown that the problem reduces to that of solving an effective Schr\"odinger equation, which is known as soon as we have solved the problem without perturbing fields.
Escaping Liberty: Western Hegemony, Black Fugitivity

This essay places Isaiah Berlin’s famous “Two Concepts of Liberty” in conversation with perspectives defined as black fugitive thought. The latter is used to refer principally to Aime Cesaire, W. E. B. Du Bois and David Walker. It argues that the trope of liberty in Western liberal political theory, exemplified in a lineage that connects Berlin, John Stuart Mill and Benjamin Constant, has maintained its universal meaning and coherence by excluding and silencing any representations of its modernity gestations, affiliations and entanglements with Atlantic slavery and European empires. This particular incarnation of theory is characterized as the Western discursive and hegemonic effects of colonial-racial foreclosure. Foreclosure describes the discursive contexts in which particular terms or references become impossible to formulate because the means by which they could be formulated have been excluded from the discursive context. Through an examination of the action of foreclosure, based largely on unraveli...
Nanosecond-Timescale Dynamics of the Viral RNA-Dependent RNA Polymerase as a Determinant of Incorporation Fidelity

The viral RNA-dependent RNA polymerase (RdRp) is required for replication of the genomes of RNA viruses. While many organisms may have evolved to make few mistakes during genome replication, RNA viruses appear to need genetic diversity for maximal fitness. This genetic diversity is created by the nucleotide misincorporation frequency of the RdRp. Perturbations in RdRp error rate therefore exhibit an antiviral effect. We have discovered a mutant poliovirus with a mutator phenotype caused by the change of His-273 of its RdRp to Arg. Kinetic experiments reveal an increase in the equilibrium constant for a conformational-change step that has been shown to be a major checkpoint for RdRp fidelity. The crystal structure of this derivative was unable to explain the biochemical observations. However, all-atom molecular dynamics (MD) simulations on the nanosecond timescale showed altered dynamics of the H273R derivative relative to the WT enzyme. By analyzing the conformational space sampled by the dihedrals of RdRp residues, we have identified RdRp residues whose dynamics correlate directly with fidelity. These residues lead to enhanced conformational flexibility of the active site of the low-fidelity H273R enzyme and diminished flexibility of the high-fidelity G64S enzyme studied previously. In general, the findings from MD simulations are supported by solution-state NMR experiments. Collectively, these experiments provide additional support for the existence of a network of RdRp residues whose dynamics control conformational changes at the active site required for incorporation fidelity. We suggest that small molecules which interfere with network dynamics should exhibit antiviral activity.
Self-cooling of highly charged ions during extraction from electron beam ion sources and traps

Abstract Evaporative self-cooling can produce a dramatic reduction in the temperature and emittance of ions extracted from electron beam ion sources and traps for favorable values of ion density and charge if the trapping potential is removed slowly. For existing electron beam ion traps, calculations predict that 20% of trapped Ar 18+ ions can be extracted with an average emittance 30 times lower than the uncooled emittance. It may be possible to construct sources of very-highly charged ions with an absolute brightness of order 2 × 10 10 ions/mm 2 mrad 2 s, a value more than four orders of magnitude larger than that of existing highly charged ion sources.
Point-of-care ultrasound diagnosis of peripheral vein septic thrombophlebitis in the emergency department

Intravenous drug users are at high risk for developing skinor subcutaneousabscesses and septic thrombophlebitis of peripheral veins. Septic thrombophlebitis is a condition characterized by inflammation and thrombosis of the vein (1). The clinical manifestations of peripheral vein septic thrombophlebitis include fever, erythema, tenderness, and purulent drainage at the site of the affected vein (2–4). The diagnosis is made based on a combination of clinical manifestations, imaging findings, and culture results. Surgical resection of the involved peripheral venous segment is usually recommended (5).
LIMIT OF A COLLECTION OF DYNAMICAL SYSTEMS: AN APPLICATION TO MODELING THE FLOW OF TRAFFIC

The flow of traffic is usually described using a continuum approach as that of a compressible fluid, a statistical approach via the kinetic theory of gases or cellular automata models. These approaches are not suitable for modeling dynamical systems such as traffic. While such systems are large collections, they are not large enough to be treated as a continuum. We provide a rationale for why they cannot be appropriately described using a continuum model, the kinetic theory of gases, or by appealing to cellular automata models. As an alternative, we develop a discrete dynamical systems approach that is particularly well suited to describe the dynamics of large systems such as traffic.
Simulation of frontal eddies on the East Florida Shelf

[1] Frontal eddies are typical features on the cyclonic side of the Florida Current (FC) along the East Florida Shelf (EFS), producing characteristic “shingle” patterns in sea surface temperature. Intensive observations and idealized numerical analyses have described such eddies over the past three decades. Here, simulations from a high-resolution (2 to 10 km), curvilinear coastal ocean circulation model demonstrate their structure and evolution with realistic bottom topography and FC over an extended domain including the Straits of Florida and the entire EFS. Simulations agree with observations in estimating translation speed, recurrence period, strength, characteristic length-scales, and overall circulation patterns. In addition, the simulations demonstrate the interactions between the frontal eddies and the meander crests and bottom topography as they translate along the EFS. Overall, a first level of model validation has been established that will facilitate consideration of the forecast problem for frontal eddies associated with the FC on the EFS.
Treatment of conjunctival squamous cell carcinoma with photodynamic therapy.

Abstract Purpose The aim of this study was to describe the clinical and angiographic response of squamous cell carcinoma (SCC) of the conjunctiva to treatment with photodynamic therapy (PDT). Design Interventional case series. Methods In a prospective study, three patients (62 to 86 years old) with SCC of the conjunctiva were treated with PDT. Patients received one to three treatments of verteporfin (6 mg/m 2 body surface area, intravenously). The light dose was calculated as 50 J/cm 2 . All tumors were irradiated 1 minute after injection. The mean follow-up time was 8.6 months (7 to 12 months). Main outcome measurements were clinical and angiographic response and treatment-related side effects. Results One week after treatment, angiographic occlusion of tumor vasculature and normal conjunctival vessels was observed in all patients. Tumor regression was noted in all patients 1 month after treatment. Two patients had complete regression (clinical and angiographic observation) after one or two treatments for the entire follow-up time. One tumor involved large aspects of the conjunctiva and cornea. In this case, only the treated areas showed tumor regression. PDT caused minimal temporary local irritation in two patients, and small conjunctival hemorrhages and mild transient chemosis in the three eyes directly after treatment. One patient had infusion-related back pain. Conclusion The preliminary results of this study suggest that PDT may be a valuable addition to the treatment of patients with SCC of the conjunctiva. However, longer follow-up is necessary to assess the duration and degree of tumor control.
Ecological and Political-Economic Analyses of Migration to a Primate City Bangkok, Thailand ca. 1970

Knowledge about internal migration to primate cities in Third World nations is limited. This article will analyze the determinants of migration to Bangkok, Thailand, ca. 1970, by focusing on the characteristics of province of origin. Theoretical issues are also addressed through the determinants analysis: The literature on primate city migration reflects a clear debate between ecological and political-economic explanations. Both explanations are defined and operationalized and their relative efficacy as predictors of migration to Bangkok is tested.
Dissociation and the fragmentary nature of traumatic memories: Overview and exploratory study

Since trauma arises from an inescapable stressful event that overwhelms people's coping mechanisms, it is uncertain to what degree the results of laboratory studies of ordinary events are relevant to the understanding of traumatic memories. This paper reviews the literature on differences between recollections of stressful and of traumatic events. It then reviews the evidence implicating dissociation as the central pathogenic mechanism that gives rise to posttraumatic stress disorder (PTSD). A systematic exploratory study of 46 subjects with PTSD indicated that traumatic memories were retrieved, at least initially, in the form of dissociated mental imprints of sensory and affective elements of the traumatic experience: as visual, olfactory, affective, auditory, and kinesthetic experiences. Over time, subjects reported the gradual emergence of a personal narrative that can be properly referred to as “explicit memory.” The implications of these findings for understanding the nature of traumatic memories are discussed.
Effects of anti-B7 monoclonal antibodies on humoral immune responses.

Abstract The costimulatory interaction between CD28 on T cells and B7-related molecules on antigen presenting cells plays an important role in a broad range of functions of the immune system, including protective immunity, tolerance induction, allograft rejection, and the development of autoimmune diseases. Monoclonal antibodies to B7-1 and B7-2 have been usedin vivoto examine the mechanisms underlying these processes and to evaluate costimulation antagonism as an approach to treatment of chronic autoimmune diseases. To determine whether anti-B7 mAb might elicit, or inhibit, a host immune response that could influence the effects of these antibodiesin vivo, we assessed the immune response to rat anti-B7-1 and anti-B7-2 mAb in healthy (BALB/c) mice and in lupus-prone NZB/NZW F1(B/W) mice. In BALB/c mice, low doses (1–10 μg) of mAb to B7-1 and mAb to B7-2 elicited brisk immune responses that occurred earlier and were significantly greater than the immune response to an isotype-matched control rat mAb to ovalbumin. In contrast, at higher doses (100–500 μg), both anti-B7 mAb, but not the control mAb, blocked the mouse anti-rat response. No such blockade occurred in B/W mice, who generated a significant mouse anti-rat response even at very high doses of anti-B7 mAb (1,000–4,000 μg). Blockade of the immune response to the anti-B7 mAb in BALB/c mice apparently did not reflect generalized immune suppression, because high doses of these mAb had little, if any effect on the humoral immune response to another antigen. These findings indicate that: (1) mAb to B7-1 and B7-2 can elicit either a potent immune response or no immune response at all depending upon the dose administered; (2) blockade of the immune response to anti-B7 mAb may be more difficult in the setting of autoimmunity; and (3) neither anti-B7-1 nor anti-B7-2 causes generalized suppression of humoral immunity.
Chronic illness and plan satisfaction under managed care

ABSTRACT: This DataWatch uses data from the 1993 Employee Health Care Value Survey (EHCVS) to compare the experiences of respondents with and without chronic illnesses under managed care. After controlling for potential confounders, we found that chronic illness was associated with increased odds of dissatisfaction in both independent practice association plans and prepaid group practices, but not under fee-for-service coverage. Chronic illness appeared to exacerbate difficulties and to attenuate the benefits experienced by healthy persons under managed care. We conclude that persons with chronic illnesses may be at particular risk under managed care; their experiences may warrant particular attention when health plan performance is being monitored.
Regulation and function of Zip4, the acrodermatitis enteropathica gene

The SLC39A (solute carrier 39A) [ZIP (Zrt-Irt-like protein)] family consists of 14 members which are thought to control zinc uptake into the cytoplasm. Among these, ZIP4 is known to be particularly important for zinc homoeostasis. Mutations in this gene cause acrodermatitis enteropathica, a rare recessive-lethal human genetic disorder. In the present paper, our studies of the regulation and function of the mouse Zip4 gene are briefly reviewed. Mouse Zip4 is expressed at highest levels in tissues involved in absorption of dietary or maternal zinc, and the gene and protein are dynamically regulated by multiple post-transcriptional mechanisms in response to zinc availability. ZIP4 accumulates at the apical surface of enterocytes and endoderm cells when zinc is deficient, because of increased stability of the mRNA and stabilization of the protein. In contrast, when zinc is replenished, the mRNA is destabilized and the protein is internalized and degraded rapidly. The critical importance of ZIP4 in zinc homoeostasis is revealed in mice with targeted deletions of this gene. Homozygous Zip4-knockout embryos die during early morphogenesis and heterozygous offspring are significantly underrepresented and display an array of developmental defects, including exencephalia, anophthalmia and severe growth retardation. Mice heterozygous for Zip4-knockout are hypersensitive to zinc deficiency, which suggests that humans heterozygous for this gene may also be very sensitive to zinc deficiency.
Thermoelectric Power of Cold-Rolled Pure Copper

The difference between the thermoelectric power of severely cold-rolled and well annealed pure copper has been measured between about 8\ifmmode^\circ\else\textdegree\fi{}K and 320\ifmmode^\circ\else\textdegree\fi{}K. The absolute thermoelectric power of our annealed and cold-worked samples were determined over the same temperature range by measuring the thermoelectric power of a thermocouple formed from annealed pure copper and pure lead. The thermoelectric power of cold-rolled copper is positive relative to annealed pure copper over the entire temperature range, and the effect of cold work is largest at very low temperatures where the thermoelectric power of annealed copper displays a pronounced minimum. Our results are in fair agreement with recent work by Powell and by van Ooijen.
Hypertensive Disorders of Pregnancy – A Life-Long Risk?!

Background: Arterial hypertension is one of the most important causes of cardiovascular diseases, and the latter are responsible for almost half of the deaths in the industrialised nations. Hypertensive disorders of pregnancy constitute one of the most frequent causes of feto-maternal morbidity and mortality; on the other hand the occurrence of a hypertensive disorder of pregnancy represents a risk for the later development of hypertension and the cardiovascular risks resulting therefrom. The aim of this article is to demonstrate the association of hypertensive disorders of pregnancy with consecutive cardiovascular diseases. Materials and Methods: Specific selective literature research. Results: After the occurrence of a hypertensive disorder of pregnancy the relative risks for hypertension are 3.7 (2.70–5.05), for ischaemic heart disease 2.2 (1.86–2.52), for cerebral insult 1.8 (1.45–2.27) and for mortality resulting from cardiovascular causes 1.5 (1.05–2.14) and are thus significant. According to a recent study 56 % of internal specialists and 23 % of gynecologists do not know about the association of preeclampsia with ischemic heart disease, 48 % and 38 % respectively are not aware of the link with stroke and 79 % and 77 % respectively are not aware of the association with a reduced life expectancy after preeclampsia. The presence of hypertension is not known by many of the patients, merely 28–38 % receive an appropriate therapy. Conclusion: Adequate follow-up after hypertensive disorders of pregnancy and the early recognition of and therapy for hypertension represent the cornerstones in the prevention of late cardiovascular sequelae. General practitioners, specialist for internal medicine and gynaecologists have a special responsibility with regard to the reduction of later complications.
Magnitude of Wastewater Treatment and Disposal Program Facing the Nation: ABSTRACT

More than 300,000 water-using industrial plants in the United States discharge 3-4 times as much oxygen-demanding wastes as all of the sewered population of the United States. Many wastes discharged by industries are toxic to aquatic life and sometimes indirectly to man. An infamous example of the latter is mercury. The volume of industrial wastewater discharge before treatment in 1964 exceeded 13 billion gal. Indications are that over half of this wastewater volume comes from 4 major industrial groups including paper, organic chemicals, petroleum refining, and steel. Industrial pollution problems are created by oxygen-demanding wastewater constituents, organic and inorganic settleable solids, suspended solids, flotable materials, End_Page 2087------------------------------ toxic metals or substances, nuisance-stimulating nutrients, and waste heat. Treatment and control processes are now available for most industrial wastes. Some pollutants including complex chemicals, however, present difficult abatement problems. The magnitude of the national industrial waste problem has remained relatively unknown. There has not been until the past few weeks a detailed inventory of industrial wastes. The Environmental Protection Agency within the past year embarked upon a three-pronged program to inventory, study, and regulate this vast waste complex. Following a test mailing to refine the questionnaire and the instructions, a voluntary national industrial wastes inventory was begun in early August 1971. A comprehensive questionnaire has been mailed to 10,000 of the major water-using industries in the United States. The inventory questionnaire was designed to collect information on quantity and quality of wastewater constituents and discharge methods. Data from the inventory will be computerized to facilitate their use. These data will be extremely valuable in all governmental activities connected with the control of industrial wastes. The Environmental Protection Agency is in partnership with the Corps of Engineers in the administration of the River and Harbor Act of 1899. Under the provision of this Act, each industrial waste discharge to the nation's waters will be regulated by a permit issued by the Corps of Engineers. The EPA will review, evaluate compliance with water quality standards, and recommend actions on the permit requests. Comprehensive studies on 20 major industrial categories have recently been completed. These studies defined a feasible effluent level based upon production units for an industrial category. They present the best and most comprehensive compilation of data now available on wastewater management from these industrial categories. End_of_Article - Last_Page 2088------------