cssi/SciSciGPT-SciSciNet huggingface dataset:
Emergency Cardiac Imaging: State of the Art

Multiple strategies and testing modalities are available to evaluate patients presenting to the emergency department with cardiac complaints. Many provide anatomic and prognostic information about coronary stenosis and long-term out-comes. Although nuclear and stress echo imaging have the ability to predict outcomes in patients in the emergency department population, the newer modalities of cardiac imaging (EBCT, MDCT,and CMR) continue to show promising results and may soon be incorporated into emergency department chest pain centers. Protocols can be developed within an institution to meet the needs of the patient population while minimizing risk and improving outcomes for all patients.
Investigation of helium addition for laser-induced plasma spectroscopy of pure gas phase systems: Analyte interactions and signal enhancement ☆

The role of helium addition on the analyte signal enhancement in laser-induced breakdown spectroscopy for analysis of pure gaseous systems was examined using carbon and hydrogen atomic emission lines. Increased analyte response, as measured by peak-to-base and signal-to-noise ratios, was observed with increasing helium addition, with maximum enhancement approaching a factor of 7. Additional measurements revealed a significant decrease in plasma electron density with increasing helium addition. To explore the mechanisms of analyte signal enhancement, the helium emission lines were also examined and found to be effectively quenched with nitrogen addition. In consideration of the data, it is concluded that the role of metastable helium is not as important as the overall changes in plasma properties, namely electron density and laser-plasma coupling. Helium addition is concluded to affect the electron density via Penning ionization, as well as to play a role in the initial plasma breakdown processes.
Private classical capacity with symmetric assistance

We study the symmetric-side-channel-assisted private capacity of a quantum channel, for which we provide a single- letter formula. This capacity is additive, convex, and, for degradable channels, equal to the unassisted private capacity. While a channel's (unassisted) capacity for private classical communication may be strictly larger than its quantum capacity, we will show that these capacities are equal for degradable channels, thus demonstrating the equivalence of privacy and quantum coherence in this context. We use these ideas to find new bounds on the key rate of quantum key distribution protocols with one-way classical post-processing. For the Bennett-Brassard-84 (BB84) protocol, our results demonstrate that collective attacks are strictly stronger than individual attacks.
Constituents of the boll weevil, Anthonomus grandis Boheman—VIII. Lipids and fatty acids in the subcellular particles of pharate pupae

Abstract 1. 1. Neutral lipids predominated in the nuclei and mitochondria fractions of pharate pupae of the boll weevil, Anthonomus grandis Boheman, and phospholipids predominated in the microsomes. 2. 2. The nuclei and mitochondria lipids contained more linoleic (18:2) acid than the microsomes. 3. 3. The decrease in 18:2 in the microsomes coincided with an increase in 18:3. 4. 4. The average number of unsaturations per molecule of lipid was higher in the phospholipids than in the neutral lipids. 5. 5. Phosphatidyl ethanolamine and phosphatidyl choline comprised 50–70 per cent of all phospholipids in all subcellular components of pharate pupae. 6. 6. Sterols and sterol derivatives were evenly distributed in the nuclei, mitochondria and microsomes of pharate pupae, pupae and adult stages of the boll weevil.
Human Papillomavirus and head and neck cancer: Epidemiology and molecular biology

Background Human papillomaviruses (HPV) are known to cause cancers of the cervix and other anogenital tract sites. Molecular biology has provided some evidence as to the specific mechanisms involved in the HPV-related carcinogenesis. Epidemiologic and molecular biology studies have also suggested that HPV infection may be associated with cancers of the head and neck. Methods This review summarizes the biology of HPV and its potential etiologic role in head and neck cancer. Published reports were used to determine the prevalence of HPV in benign, precancerous, and neoplastic lesions of the oral cavity, pharynx, and larynx. The prevalence was also examined by head and neck site, HPV type, and method of HPV detection. In addition, the occurrence of HPV in normal head and neck tissue, epidemiologic factors related to HPV infection, and clinical implications are discussed. Results Overall, the frequency of HPV in benign and precancerous lesions ranged from 18.5% to 35.9%, depending upon the detection methodology. Based upon the most sensitive method of detection, polymerase chain reaction (PCR), the overall prevalence of HPV in head and neck tumors was 34.5% (416 of 1205 tumors). The majority of HPV-positive tumors contained the “high risk” HPV types 16 (40.0%) and 18 (11.9%). Among head and neck sites, HPV was most often detected in tumors of the oral cavity (59%), followed by the pharynx (43%), and larynx (33%). The frequency of HPV positivity in oral samples from healthy individuals ranged from 1% to 60%. A limited number of descriptive and analytic epidemiologic studies have indicated that age (<60 years) and sex (male) were associated with the presence of HPV in the tumor, whereas tobacco and alcohol use were not. The relationship between HPV and survival is unclear, with few comprehensive studies currently available. Conclusions The prevalence of HPV, particularly the high-risk types, suggests a potential etiologic role for the virus in head and neck cancer. Molecular biology has provided important data on the interaction of the HPV oncoproteins with genes important in cell cycle control. Nonetheless, more basic research is needed to describe the physical state of the virus in a variety of cell types and the interaction with other genes. In addition, epidemiologic research is required to further understand the association between HPV and demographic and other risk factors as well as possible routes of transmission. Finally, much work is warranted to provide a definitive assessment of the prognostic significance of HPV in head and neck cancer. © 1998 John Wiley & Sons, Inc. Head Neck 20:250–265, 1998.
Responsive Satellites Through Ground Track Manipulation Using Existing Technology

Traditional space operations are characterized by large, highly-technical, long-standing satellite systems that cost billions of dollars and take decades to develop. Many branches of the US government have recognized the problem of sustaining current space operations and have responded by heavily supporting research and development in a field known as Operationally Responsive Space (ORS). This ORS research focuses on hardware, interfaces, rapid launch and deployment with the overall goal of reducing per-mission-cost down to $20 million. However, there are few studies on the feasibility of maneuvering satellites in lowEarth orbit (LEO) from a ground-track perspective once an asset is launched. We can achieve operational responsiveness by changing the ground track of a given satellite and thereby a geographical target location by applying existing thruster technology. Therefore it is not so much a new technology but a change in the Concept of Operations (CONOPS) of today’s space systems application. The existing paradigm on maneuvering is that it is costprohibitive, especially in performing orbital plane changes, thus orbit-changing maneuvers are only done at the beginning-of-life to establish the service orbit, end-of-life for disposal, and when absolutely necessary for the safety of the system (collision avoidance). This paradigm along with traditional space programs have to change and a transition to responsive and maneuverable systems must take place to meet the needs of space users in a timely manner. The analysis we present here shows that a satellite equipped with a standard chemical propulsion thruster in a 60-degree inclined, 500-km altitude orbit can move the ground over-flight target anywhere on the globe (within 60 degrees north and south latitudes) in as little as ten hours from the time of the maneuver with a fuel expenditure, measured in change in velocity (ΔV), of 100 meters-per-second. Similarly, a more efficient electric propulsion thruster can provide the same maneuverability in 27 hours from the start of the maneuver while expending the same amount of ΔV. This research demonstrates that existing technology can maneuver a satellite significantly to change its ground track to overfly a desired target on Earth in a relatively short period of time and well-within standard fuel budgets.
A comparison of methods for measuring extractable Ca, Mg, K, Na, Mn, Al, Fe, and P from New England forest soils

Abstract An experiment was designed to evaluate several of the commonly used extractants and methods for determining “available”; elements in soils. The purpose of the study was to evaluate the suitability of these extraction procedures for use on forest soils typical for New England commercial forests. The extraction procedures selected included NH4OAc pH 4.8, NH4OAc pH 7.0, NH4Cl, Double Acid, Bray, and Mehlich methods. The elements measured varied somewhat by procedure but included the base cations, Al, Fe, Mn, and P. As a bioassay of element availability, a greenhouse study was conducted using six forest soil materials from different horizon types (i.e. O, Ap, B) and three conifer seedling species (red spruce, balsam fir, and white pine). Relatively small differences among extraction procedures were found among the methods used for exchangeable Ca, Mg, K, and Na. Large differences, however, were found among the different horizon types in the amount of exchangeable base cations present. In contrast, si...
Transition Probabilities of the Hydrogen Atom from Noncompact Dynamical Groups

In order to describe electromagnetic dipole transitions of the H atom within the framework of dynamical groups, an explicit irreducible representation of the Lie algebra $O(4.2)$ has been found on the space of bound-state wave functions. This representation remains irreducible when restricting to the subalgebra $O(4,1)$. The transformation properties of the dipole operator in $O(4,2)$ have been specified. The description becomes particularly simple by the introduction of a one-parameter family of representations of $O(4,2)$. Finally, position representations of the generators of $O(4,2)$ have been given.
Clinical evaluations of composite resin restorations in primary molars: a 4-year follow-up study

A total of 96 composite resin restorations were placed in primary molars. After 4 years, 44 restorations were examined. The wear rate was similar to that of enamel in primary molars. The material had excellent radiopacity and color-matching properties.
Conductance of a Molecular Junction

Molecules of benzene-1,4-dithiol were self-assembled onto the two facing gold electrodes of a mechanically controllable break junction to form a statically stable gold-sulfur-aryl-sulfur-gold system, allowing for direct observation of charge transport through the molecules. Current-voltage measurements at room temperature demonstrated a highly reproducible apparent gap at about 0.7 volt, and the conductance-voltage curve showed two steps in both bias directions. This study provides a quantative measure of the conductance of a junction containing a single molecule, which is a fundamental step in the emerging area of molecular-scale electronics.
Comparative Pharmacokinetics of Coumarin Anticoagulants XV: Relationship between Pharmacokinetics of Dicumarol and Warfarin in Rats

The distribution, elimination, and anticoagulant effect of dicumarol and warfarin were determined in adult males rats following intravenous injection of single doses of these drugs in crossover experiments. The biological half-life of dicumarol ranged from 5 to 28 hr; that of warfarin ranged from 9 to 30 hr. There was a statistically significant correlation between the following pharmacokinetic characteristics of dicumarol and warfarin in individual animals: biological half-life, apparent volume of distribution, total plasma clearance, and concentration in plasma eliciting one-half the maximum anticoagulant effect (effective concentration). The mean ratio of the respective biological half-lives (warfarin/dicumarol) was 1.42, and that of the apparent volumes of distribution was 1.50. The ratio of the effective plasma concentrations (dicumarol/warfarin) was correlated negatively with the half-life of dicumarol and positively with the ratio of the half-life values (warfarin/dicumarol) in individual animals. Additional studies with serum samples from other rats showed pronounced interindividual differences in the serum protein binding of both dicumarol and warfarin and a strong correlation between the protein binding of these two drugs in serum of individual animals. The results of this study, together with the results of previous studies in this series, indicate that serum protein binding is the major determinant of interindividual differences in the pharmacokinetics of dicumarol and warfarin in rats under these experimental conditions.
C. elegans fat storage and metabolic regulation

C. elegans has long been used as an experimentally tractable organism for discovery of fundamental mechanisms that underlie metazoan cellular function, development, neurobiology, and behavior. C. elegans has more recently been exploited to study the interplay of environment and genetics on lipid storage pathways. As an experimental platform, C. elegans is amenable to an extensive array of forward and reverse genetic, a variety of "omics" and anatomical approaches that together allow dissection of complex physiological pathways. This is particularly relevant to the study of fat biology, as energy balance is ultimately an organismal process that involves behavior, nutrient digestion, uptake and transport, as well as a variety of cellular activities that determine the balance between lipid storage and utilization. C. elegans offers the opportunity to dissect these pathways and various cellular and organismal homeostatic mechanisms in the context of a genetically tractable, intact organism.
Changes in Planktonic Diatoms and Water Transparency in Hatchery Bay, Bass Island Area, Western Lake Erie Since the Establishment of the Zebra Mussel

Total planktonic diatoms were analyzed from water samples collected in 1984-1986 (pre-zebra mussel period) and 1990-1992 (post-zebra mussel period) in Hatchery Bay of western Lake Erie. Planktonic diatom abundances for one post-zebra mussel year, 3 April 1990 - 26 March 1991, and weekly April/May frustules for 1990, 1991, and 1992 were compared to counts from the 1980s and to counts in the literature for the years 1960-1965. Water transparency (Secchi disk depth), measured concomitantly with the collection of plankton samples, was compared between the two periods, 1984-1986 and 1990-1992. Transparency was found to be 100% higher in the post-zebra mussel period. Mean numbers of total planktonic diatoms in the full post-zebra mussel year were lower than in the pre-zebra mussel periods: 86% lower than in 1984-1986 and 92% lower than in 1961-1965. Abundances of total diatoms in the weekly April/May samples for 1990, 1991, and 1992 were within 9% of each other and between 82% and 91 % lower than in any of the weekly April/May periods of the 8 pre-zebra mussel years. The recent increase in water transparency and decrease in planktonic diatoms in Hatchery Bay are most likely the direct result of the filtering activities of the zebra mussel, Dreissena polymorpha. The changes may signal an alteration in the food web in western Lake Erie.
A Simplified EM Reconstruction Algorithm for TOFPET

A simplified expectation-maximization (EM) algorithm for image reconstruction in positron emission tomography with time-of-flight information (TOFPET) has been developed. This new method requires substantially less computation time than the estimated posterior-density weighting (EPDW) method developed by Snyder and Politte [1,2]. Mathematically, the integration of TOFPET images at different angles yields a 2-D image which is the convolution of the true image and a rotationally symmetric point spread function (PSF). The new method uses this PSF to construct the probability functions and employs the summed TOFPET image as the incomplete data set in the expectation step of the EM algorithm; thus, the time-costly angle-by-angle operations required in EPDW are reduced to a single operation, cutting the processing time by a factor of approximately l/M for an image reconstruction using M projection angles. Results from computer simulation studies suggest that this new method may offer image quality superior to that produced by other algorithms.
Behavioral responses to physical vs. social novelty in male and female laboratory rats

Abstract Most behavioral tests used with laboratory rodents involve measuring behavioral responses to physical novelty. However, laboratory rodents are often derived from highly social species for which novel social stimuli may induce different levels of fear or curiosity compared to novel physical objects. We hypothesized that behavioral responses will differ in response to novel physical vs. social cues, and that females may show more exploration of social novelty, based on prior studies indicating that females more actively seek social support during duress compared to males. We compared young (55-day-old) Sprague-Dawley rats’ responses to an arena filled with novel objects (“physical”) or a novel same-sex caged conspecific (“social”). Rats were more active and spent twice as much time in contact with the novel social stimulus compared to novel physical stimuli. Although females were more active than males, females were not particularly more exploratory in the social arena compared to males. The results indicate that a novel social partner (even a caged one with limited ability to interact) elicits more exploration than novel objects for both male and female rats.
Exergetic analysis of power plants operating on biomaterials

There is growing interest worldwide in biomaterials for power generation as substitutes or supplements for hydrocarbon fuels. In this paper, biomaterials-based power generation is evaluated and compared with widely used hydrocarbon-based generation. Exergy, the theoretical maximum work extractable from a system as it interacts with a particular reference state, is used as the parameter to measure the overall effectiveness of the thermomechanical energy conversion and detect inefficiencies. The destruction of exergy happens when irreversible mechanical or chemical processes occur during power generation. Combustion constitutes the main portion of the exergy destruction in power plants and biomaterials have a significant advantage over fossil fuels when the amount of exergy destruction is compared between the two. This exergetic study on power plants operating on biomaterials will be further developed into economic and environmental research.
Social welfare losses due to a monopoly

Abstract We compare the R&D decision of a second best social surplus maximizer to that of a profit maximizing monopolist in a second best world, namely one in which a monopolist makes production decisions. We show that a monopolist underinvests in R&D relative to a second best social surplus maximizer. We show that the expected present value social surplus under a monopoly situation increases with the production technology except at the technology level where a monopolist stops doing R&D.
Density and distribution of a colonizing front of the American black bear Ursus americanus

Abstract Effective management of small expanding populations is aided by the availability of reliable estimates of distribution, as well as by demographic characteristics such as population density, genetic diversity and sex ratio. The range of the black bear Ursus americanus in the southeastern United States is expanding to include areas from which it has been extirpated for more than a century. Lack of baseline demographic data in recently reoccupied areas leaves little information on which to base emerging management needs. We estimated the current extent of expansion at the colonizing front of a black bear population in the central Appalachian Mountains and identified landscape-scale habitat characteristics affecting the expansion. In 2007, we genotyped hair samples collected throughout a 8,205-km2 area at six microsatellite loci to identify individual black bears and estimate genetic diversity. We used capture-recapture and occupancy analyses to estimate density and distribution of black bears in our...
Approach and avoidance motivation as predictors of pro-relationship behaviors

Abstract Pro-relationship behaviors, such as willingness to sacrifice, are assumed to be driven by both approach and avoidance motivation. However, this assumption has not been directly tested. In two studies, we examined how individual differences in approach and avoidance motivation predicted pro-relationship behavior. In Study 1, avoidance (but not approach) motivation uniquely predicted sacrificial behavior. In Study 2, sacrificing was uniquely predicted by avoidance motivation, whereas accommodation was uniquely predicted by approach motivation. These data suggest that although both sacrificing and accommodation are pro-relationship behaviors, they are driven by different motivational systems, which in turn may result in different long-term relational outcomes.
Understanding How Lake Populations of Arctic Char are Structured and Function with Special Consideration of the Potential Effects of Climate Change: a Multi-Faceted Approach

Size dimorphism in fish populations, both its causes and consequences, has been an area of considerable focus; however, uncertainty remains whether size dimorphism is dynamic or stabilizing and about the role of exogenous factors. Here, we explored patterns among empirical vital rates, population structure, abundance and trend, and predicted the effects of climate change on populations of arctic char (Salvelinus alpinus) in two lakes. Both populations cycle dramatically between dominance by small (≤300 mm) and large (>300 mm) char. Apparent survival (Φ) and specific growth rates (SGR) were relatively high (40-96%; SGR range 0.03-1.5%) and comparable to those of conspecifics at lower latitudes. Climate change scenarios mimicked observed patterns of warming and resulted in temperatures closer to optimal for char growth (15.15 °C) and a longer growing season. An increase in consumption rates (28-34%) under climate change scenarios led to much greater growth rates (23-34%). Higher growth rates predicted under climate change resulted in an even greater predicted amplitude of cycles in population structure as well as an increase in reproductive output (Ro) and decrease in generation time (Go). Collectively, these results indicate arctic char populations (not just individuals) are extremely sensitive to small changes in the number of ice-free days. We hypothesize years with a longer growing season, predicted to occur more often under climate change, produce elevated growth rates of small char and act in a manner similar to a "resource pulse," allowing a sub-set of small char to "break through," thus setting the cycle in population structure.
The development of auditory behavior (or what the anatomists and physiologists have to explain)

Objective: Infants' and children's performance in detecting and discriminating between sounds is often poorer than that of adults. Behavioral immaturity often coexists with mature-looking morphology and physiological responses from the peripheral and brain stem structures that limit performance among adults. One interpretation of this pattern of results is that hearing is mature but some unnamed central process is immature. Design: The approach to the problem taken here is to view auditory behavior as the process to be explained and physiological or anatomical measurements as giving us clues about the underlying processes. The development of four aspects of hearing-frequency resolution, detection, temporal resolution, and intensity resolution - is reviewed in this paper, and new data addressing these topics are presented. Results: Frequency resolution, detection, temporal resolution, and intensity resolution all undergo development during infancy and childhood, although the mechanisms underlying development vary across capacity and developmental period. Conclusions: A coherent argument can be made that both primary auditory pathway maturation and maturation of specific central processes are involved in development. Both types of maturation continue into childhood, and both types of maturation can influence hearing directly.
Direct Evidence for the Cathodic Depolarization Theory of Bacterial Corrosion

Cathodic depolarization of mild steel by Desulfovibrio desulfuricans was demonstrated with benzyl viologen used as an electron acceptor. Direct measurement of the cathodic depolarization current indicated a maximum current density of 1 microampere per square centimeter. Aluminum alloys were also cathodically depolarized by the organism.
Mortality differentials between rural and urban areas of states in the Northeastern United States 1890-1900.

Abstract Data from a number of countries show much higher mortality rates in urban than in rural areas in the nineteenth century. In this paper we examine the urban-rural mortality differential in the death registration states of the United States in 1890 and 1900. Before proceeding with the analysis, the data are evaluated and we determine that the data used for the 1900 analysis are more complete than data used in other analyses for the same date. An attempt is made to correct for the deficiencies in the 1890 data. When the urban and rural mortality levels are examined for individual states at both dates, urban mortality is generally higher than rural mortality. However, there is variability across states in urban mortality levels, rural mortality levels, and the urban-rural mortality differences. In general, the urban-rural mortality difference is larger in 1890 than in 1900. When the urban-rural mortality differences are examined in terms of the causes of death which account for the differential, we conclude that higher urban mortality rates are generally attributable to a few diseases—tuberculosis, diarrheal diseases and several other communicable diseases—the transmission of which depend heavily on close human contact or contamination of the environment.
Optimal Internal Structure of Volumes Cooled by Single-Phase Forced and Natural Convection

Design is the permanent struggle for better and better global system performance, under imposed constraints. This paper reviews a body of electronics cooling results that illustrate how the physical structure of the system—its architecture, construction— springs out of the pursuit of objective under constraints. The same ‘constructal’ principle accounts for the generation of geometric form in other flow systems, engineered and natural @1#. They are part of a more general trend in which a greater appreciation of geometric form, scales and similitude is leading us to more powerful ~unifying! correlations of heat and fluid flow results developed originally for individual configurations. Professor Yovanovich has played a pioneering role in this direction @2‐4 #. Consider the main issues while designing a package of electronic components that must fit inside a given volume—the global constraint. The objective of the design is to install as much circuitry as possible in this volume. In rough terms, this is equivalent to installing as much heat generation rate ~q! as possible, because electrical components generate heat. The highest temperatures in the package ~the hot spots! must not exceed a specified value, Tmax : this is also a global constraint, because the maximum temperature is a feature of the entire system. The exact location of the hot spots is not an issue. If the local temperature ~T! rises above this allowable ceiling, the electronic functioning of the local component is threatened. In sum, the thermal design is better when q is larger. In other words, the design is better when the global thermal conductance ratio q/(Tmax2T0) is larger, where T0 is the initial ~reference, sink! temperature of the coolant that absorbs q. Papers and reviews of the electronics cooling literature illustrate this design philosophy @5‐13#.
Metabolites of acetaminophen trigger Ca2+ release from liver microsomes

Abstract Release of mitochondrial calcium is believed to play a key role in the toxicity of acetaminophen in biological systems. Elevated cytosolic Ca2+ may also result from activation of calcium releasing channels. The major metabolites of acetaminophen, benzoquinone imine and 1,4-benzoquinone, induced Ca2+ release in isolated rat liver microsomes. The 1,4-benzoquinone-induced release of calcium was suppressed by ryanodine and fully inhibited by reduced glutathione. Concentrations of 1,4-benzoquinone that induced Ca2+ release did not affect the activity of the microsomal Ca2+, Mg2+–APTase. The binding of [3H]ryanodine to liver microsomes, however, was significantly decreased by 1,4-benzoquinone, suggesting a direct interaction of this metabolite with the ryanodine-binding protein (ryanodine receptor). These results suggest that cellular Ca2+ levels may be elevated by acetaminophen by pathways involving, in part, activation of Ca2+ releasing channels such as the ryanodine receptor.
Cytokines: sources, receptors and signalling

Cytokines are a family of protein mediators that are important in transducing information between various cell types. These messengers are synthesized by a broad spectrum of cells. Cellular sources of cytokines include those cell types considered to play pivotal roles in the immune system as well as in inflammatory responses, including lymphocytes, monocytes and mast cells. Emerging data indicate that non-immune cells, including epithelial cells and fibroblasts, may also be important sources of certain cytokines. Cytokines fulfill a number of roles during immune and inflammatory reactions, and may display overlapping or redundant functions. In part, this redundancy may arise from the fact that cytokine receptors are not all unique entities, but may be divided into families. Many cytokine receptors have a subunit structure, with common subunits shared between receptors, and serving as affinity modifiers/signal transducers. Cytokines exert their effects on target cells by activating intracellular signalling mechanisms. In addition to 'classical' signal transduction path-ways, new data indicate that cytokines may also exemplify molecules that utilize novel signalling mechanisms, including the Jak-STAT pathways of transcriptional regulation and pathways involving the novel lipid second messenger, ceramide. In conclusion, molecular techniques have enabled the identification of many new cytokines, and the elucidation of their binding sites and mechanisms of action. This information has provided new insights into this complex area. Moreover, an understanding of the molecular basis of cytokine action and the pathways that lead to their acute and chronic effects may, in turn, facilitate interventions to prevent or modify their actions in disease states.
Idempotent filtering in spectral and spectral element methods

The comparison of numerical results for implicit-explicit and fully explicit Runge-Kutta time integration methods for a nozzle flow problem shows that filtering can significantly degrade the accuracy of the numerical solution for long-time integration problems. We demonstrate analytically and numerically that filtering-in-time errors become additive for @?u"N(x,t+k@Dt)-u"N(x,t)@?@?@?u"N(x,t)@? when nonidempotent filters are used, and suggest the development and implementation of idempotent filters.
Detecting traffic differentiation in backbone ISPs with NetPolice

Traffic differentiations are known to be found at the edge of the Internet in broadband ISPs and wireless carriers [13, 2]. The ability to detect traffic differentiations is essential for customers to develop effective strategies for improving their application performance. We build a system, called NetPolice, that enables detection of content- and routing-based differentiations in backbone ISPs. NetPolice is easy to deploy since it only relies on loss measurement launched from end hosts. The key challenges in building NetPolice include selecting an appropriate set of probing destinations and ensuring the robustness of detection results to measurement noise.We use NetPolice to study 18 large ISPs spanning 3 major continents over 10 weeks in 2008. Our work provides concrete evidence of traffic differentiations based on application types and neighbor ASes. We identify 4 ISPs that exhibit large degree of differentiation on 4 applications and 10 ISPs that perform previous-AS hop based differentiation, resulting in up to 5% actual loss rate differences. The significance of differences increases with network load. Some ISPs simply differentiate traffic based on port numbers irrespective of packet payload and the differentiation policies may only be partially deployed within their networks. We also find strong correlation between performance differences and Type-of-Service value differences in the traffic.
Biosynthesis and endocrine control of the production of the German cockroach sex pheromone 3,11-dimethylnonacosan-2-one

The biosynthesis and endocrine regulation of sex pheromone production in the female German cockroach (Blattella germanica) were determined. Radio-TLC and radio-GLC were used to demonstrate the metabolism of 3,11-dimethylnonacosane, a major cuticular lipid component, to the corresponding alkan-2-ol and methyl ketone. [11,12-3H2]-3,11-Dimethylnonacosan-2-ol was efficiently metabolized to the methyl ketone, and radio-GLC showed that the methyl ketone product from both experiments was coeluted with a methyl ketone standard. A comparison of the metabolism of the labeled dimethylalkane and dimethylalkan-2-ol by age and sex showed that both males and females from day 1 through day 9 after adult emergence readily metabolized the alcohol to the corresponding methyl ketone, whereas only females of 5-9 days postemergence efficiently converted the labeled dimethylalkane to the corresponding methyl ketone. Application of the juvenile hormone analog hydroprene induced significant increases in the conversion of the labeled hydrocarbon to the methyl ketone in starved adult females as well as in females fed a protein-free diet, conditions under which endogenous juvenile hormone biosynthesis is nearly undetectable. These data show that the methyl ketone sex pheromone is formed by the hydroxylation and oxidation of the 3,11-dimethylalkane at the 2 position, show that the age- and sex-specific step in this process is the conversion of 3,11-dimethylnonacosane to 3,11-dimethylnonacosan-2-ol, and provide evidence that juvenile hormone regulates sex pheromone production in the German cockroach.
Grain orientation effects on dynamic strength of FCC multicrystals at low shock pressures: a hydrodynamic instability study

Variability in local dynamic plasticity due to material anisotropy in polycrystalline metals is likely to be important on damage nucleation and growth at low pressures. Hydrodynamic instabilities could be used to study these plasticity effects by correlating measured changes in perturbation amplitudes at free surfaces to local plastic behaviour and grain orientation, but amplitude changes are typically too small to be measured reliably at low pressures using conventional diagnostics. Correlations between strength at low shock pressures and grain orientation were studied in copper (grain size ≈ 800 μm) using the Richtmyer–Meshkov instability with a square-wave surface perturbation (wavelength = 150 μm, amplitude = 5 μm), shocked at 2.7 GPa using symmetric plate impacts. A Plexiglas window was pressed against the peaks of the perturbation, keeping valleys as free surfaces. This produced perturbation amplitude changes much larger than those predicted without the window. Amplitude reductions from 64 to 88% we...
The Institute for the Study of Non–Model Organisms and other fantasies

In his classic novel Invisible Cities, Italo Calvino describes a series of fantastic imagined cities that fulfill core human needs that remain unmet in ordinary cities. In light of the recent founding of a number of high-profile biomedical institutes, Calvino's descriptions encourage us to consider the unmet needs of the biomedical community and imagine unorthodox institutes designed to fulfill these needs.
Prototype 500 MHz planar RF input window for a B-factory accelerating cavity

The Laboratory of Nuclear Studies is proposing an upgrade to the existing CESR electron-positron storage ring to make possible the study of CP violation of B meson decays. This B-Factory, because of the required luminosity and the resultant high beam current, will require very high RF power levels to replace the synchrotron radiation and the HOM (higher order mode) energy losses of the beams. The proposed design would require 16 superconducting cavity structures, each with an RF input power of approximately 400 kW at 500 MHz. The design requirements and the feasibility of a planar waveguide vacuum window are considered. Low-power and high-power measurements are described. The test results are provided. >
Using the EM algorithm to increase the number of signals estimable by 2-D parametric techniques

This paper provides an easy method for increasing the number of modes estimable by 2-D parameter estimation schemes which use a single snapshot of the data. For data of size M/sub 1//spl times/M/sub 2/ few of these techniques allow the number of modes to exceed M/sub 1/ and/or M/sub 2/. As these restrictions are not inherent to the model but the algorithms themselves, this problem is circumvented by treating the observed data as an incomplete version of a larger data set. An existing 2-D parameter estimation scheme is then used for the maximization (M) step of the expectation-maximization (EM) algorithm. In this way, one can increase the number of modes the scheme can estimate without changing the scheme itself.
ENTRY-LEVEL HEAVY TRUCK DRIVERS AND HIGHWAY SAFETY: IS IT FINALLY TIME FOR FEDERALLY MANDATED TRAINING?

This article examines the need for mandated instruction and a uniform curriculum for entry-level commercial drivers. The study also addresses the discontinuity resulting from the establishment of a uniform licensing standard without requiring preparatory training. The research involves a review of Federal regulations pertaining to obligatory operator instruction in the air, water and rail mode. The investigation concludes that weak support and lobbying efforts by certain trucking interests have thwarted the adoption of mandatory instruction and/or a uniform curriculum. The study also highlights a pressing need for policy revision given the imminent retirement of many “baby boom” generation drivers.
Reducing dynamic power dissipation in pipelined forwarding engines

Power consumption has become a limiting factor in next-generation routers. IP forwarding engines dominate the overall power dissipation in a router. Although SRAM-based pipeline architectures have recently been developed as a promising alternative to power-hungry TCAM-based solutions for high-throughput IP forwarding, it remains a challenge to achieve low power. This paper proposes several novel architecture-specific techniques to reduce the dynamic power consumption in SRAM-based pipelined IP forwarding engines. First, the pipeline architecture itself is built as an inherent cache, exploiting the data locality in Internet traffic. The number of memory accesses which contribute to the majority of power consumption, is thus reduced. No external cache is needed. Second, instead of using a global clock, different pipeline stages are driven by separate clocks. The local clocking scheme is carefully designed to exploit the traffic rate variation and improve the caching performance. Third, a fine-grained memory enabling scheme is developed to eliminate unnecessary memory accesses, while preserving the packet order. Simulation experiments using real-life traces show that our solutions can achieve up to 15-fold reduction in dynamic power dissipation, over the baseline pipeline architecture that does not employ the proposed schemes. FPGA implementation results show that our design sustains 40 Gbps throughput for minimum size (40 bytes) packets while consuming a small amount of logic resources.
Efficacy of Oral Ramoplanin for Inhibition of Intestinal Colonization by Vancomycin-Resistant Enterococci in Mice

Ramoplanin is a glycolipodepsipeptide antibiotic with activity against gram-positive bacteria that is in clinical trials for prevention of vancomycin-resistant Enterococcus (VRE) bloodstream infections and treatment of Clostridium difficile diarrhea. Orally administered ramoplanin suppresses VRE intestinal colonization, but recurrences after discontinuation of treatment have frequently been observed. We used a mouse model to examine the efficacy of ramoplanin for inhibition of VRE colonization and evaluated the etiology of recurrences of colonization. Eight days of treatment with ramoplanin (100 microg/ml) in drinking water suppressed VRE to undetectable levels, but 100% of mice developed recurrent colonization; a higher dose of 500 microg/ml in water was associated with recurrent colonization in 50% of mice. Two of eight (25%) mice treated with the 100-microg/ml dose of ramoplanin had low levels of VRE in their cecal tissues on day 8 despite undetectable levels in stool and cecal contents. Mice that received prior ramoplanin treatment did not develop VRE overgrowth when challenged with 10(7) CFU of oral VRE 1, 2, or 4 days later. In communal cages, rapid cross-transmission and overgrowth of VRE was observed among clindamycin-treated mice; ramoplanin treatment effectively suppressed VRE overgrowth in such communal cages. Ramoplanin treatment promoted increased density of indigenous Enterobacteriaceae and overgrowth of an exogenously administered Klebsiella pneumoniae isolate. These results demonstrate the efficacy of ramoplanin for inhibition of VRE colonization and suggest that some recurrences occur due to reexpansion of organisms that persist within the lining of the colon. Ramoplanin treatment may be associated with overgrowth of gram-negative bacilli.
Oral deformities in several species of frogs from the Savannah River Site, USA

Tadpoles of seven species of frogs from 22 wetlands on the Savannah River Site in South Carolina, USA, were examined to assess the prevalence of mouth-part deformities and axial skeletal deformities. Species examined included southern toad (Bufo terrestris), pine woods treefrog (Hyla femoralis), spring peeper (Pseudacris crucifer), southern chorus frog (P. nigrita), ornate chorus frog (P. ornata), bronze frog (Rana clamitans), and southern leopard frog (R. utricularia). Of the 4,335 tadpoles examined in 1997 and 1998, 6% exhibited mouth-part deformities and none exhibited axial skeletal deformities. However, significant interspecific differences existed for both prehind-limb and posthind-limb developmental stages. The highest percentage of deformities in prehind-limb stage occurred in spring peeper (27%), ornate chorus frog (29%), and bronze frog (33%), and the lowest percentage occurred in southern toad (5.5%) and southern chorus frog (4.8%). The frequency of mouth deformities decreased from the prehind-to posthind-limb developmental stage for six of seven species and was significant for southern toad and ornate chorus frog. Differences existed in the percent of mouth-part deformities among species in the same wetland and among wetlands for two species (southern toad and southern leopard frog). Among southern toads, mouth-part deformities increased with increasing hydroperiod length. Oral deformities may lead to lowered feeding success and lowered survival of tadpoles, resulting in a lower percentage of deformities in the posthind-limb stage.
Nitrous Oxide Production by Organisms Other than Nitrifiers or Denitrifiers

Heterotrophic bacteria, yeasts, fungi, plants, and animal breath were investigated as possible sources of N2O. Microbes found to produce N2O from NO3− but not consume it were: (i) all of the nitrate-respiring bacteria examined, including strains of Escherichia, Serratia, Klebsiella, Enterobacter, Erwinia, and Bacillus; (ii) one of the assimilatory nitrate-reducing bacteria examined, Azotobacter vinelandii, but not Azotobacter macrocytogenes or Acinetobacter sp.; and (iii) some but not all of the assimilatory nitrate-reducing yeasts and fungi, including strains of Hansenula, Rhodotorula, Aspergillus, Alternaria, and Fusarium. The NO3−-reducing obligate anaerobe Clostridium KDHS2 did not produce N2O. Production of N2O occurred only in stationary phase. The nitrate-respiring bacteria produced much more N2O than the other organisms, with yields of N2O ranging from 3 to 36% of 3.5 mM NO3−. Production of N2O was apparently not regulated by ammonium and was not restricted to aerobic or anaerobic conditions. Plants do not appear to produce N2O, although N2O was found to arise from some damaged plant tops, probably due to microbial growth. Concentrations of N2O above the ambient level in the atmosphere were found in human breath and appeared to increase after a meal of high-nitrate food.
Health Psychology in African Settings A Cultural-psychological Analysis

African settings provide an important context in which to examine the relationship between cultural beliefs and health. First, research in African settings helps illuminate the sociocultural grounding of health and illness: the idea that beliefs play a constitutive role in the experience of distress. Second, research in African settings helps to illuminate the cultural grounding of health sciences: the idea that theory and practice reflect particular constructions of reality. We examine these ideas in the context of three research examples: the prominent experience of personal enemies; epidemic outbreaks of genital-shrinking panic; and fears about sabotage of vaccines in immunization campaigns.
A unified framework for explanation-based generalization of partially ordered and partially instantiated plans

Abstract Most previous work in explanation-based generalization (EBG) of plans dealt with totally ordered plans. These methods cannot be directly applied to generalizing partially ordered partially instantiated plans, a class of plans that have received significant attention in planning. In this paper we present a natural way of extending the explanation-based generalization methods to partially ordered partially instantiated (POPI) plans. Our development is based on modal truth criteria for POPI plans [3]. We develop explanation structures from these truth criteria, and use them as a common basis to derive a variety of generalization algorithms. Specifically we present algorithms for precondition generalization, order generalization, and possible correctness generalization of POPI plans. The systematic derivation of the generalization algorithms from the modal truth criterion obviates the need for carrying out a separate formal proof of correctness of the EBG algorithms. Our development also systematically explicates the tradeoffs among the spectrum of possible generalizations for POPI plans, and provides an empirical demonstration of the relative utility of EBG in partial ordering, as opposed to total ordering, planning frameworks.