cssi/SciSciGPT-SciSciNet huggingface dataset:
A Review of Hydraulic Fracture Modeling—II: 3D Modeling and Vertical Growth in Layered Rock

Revue des modeles tridimensionnels de fractures a couplage fluide/solide et de quelques problemes bi et tridimensionnels fondamentaux de mecanique de fracture lineaire elastique applicable a la croissance de fractures au voisinage de discontinuites in situ. Evaluation de l'etat actuel de la recherche en matiere de construction de modeles et d'etudes de croissance verticale
Note on the Oslo algorithm

Abstract The Oslo algorithm is a recursive method for updating the B-spline representation of a curve or tensor product surface when extra knots are added. In the present note, the derivation of this method is simplified.
Uncertainty and sensitivity analysis in performance assessment for the proposed repository for high-level radioactive waste at Yucca Mountain, Nevada

Extensive work has been carried out by the U.S. Department of Energy (DOE) in the development of a proposed geologic repository at Yucca Mountain (YM), Nevada, for the disposal of high-level radioactive waste. As part of this development, an extensive performance assessment (PA) for the YM repository was completed in 2008 [1] and supported a license application by the DOE to the U.S. Nuclear Regulatory Commission (NRC) for the construction of the YM repository [2]. This presentation provides an overview of the conceptual and computational structure of the indicated PA (hereafter referred to as the 2008 YM PA) and the roles that uncertainty analysis and sensitivity analysis play in this structure.
A critique of dissipative structures in the human realm

Abstract The essay constitutes an exercise in philosophical critique of the claims made for nonlinear functional descriptions in the human realm. The examination is grounded in both mathematical and philosophical concern. The former considers the circumstances under which bifurcation is conceptually admissible, and the practical difficulties of determining whether a parameter characterizing the trajectory of a complex regional system has passed through such a value. The latter considers the difficulty of mapping the sequential geographic configurations of an actual regional history onto such a mathematical structure, and of marshalling empirical evidence that bifurcation has occurred.
Holocene fire regimes, vegetation and biogeochemistry of an ecotone site in the Great Lakes Region of North America

AbstractQuestion: As anthropogenic change pushes ecosystems towards historicallynovel states, understanding how landscape disturbances interact with climatevariabilitybecomesincreasinglyimportant.WereconstructedtheHoloceneveg-etation and ﬁre history of a small watershed to investigate the linkages amongdisturbance regimes, biogeochemical cycling and ecosystem structure. Speciﬁ-callyweasked:(i)howdocompositionalandstructuralchangesinforestecosys-tems modify ﬁre regimes; and (ii) how do changes in fuel type and ﬁre regimesimpactbiogeochemicalcycling?Location: Comstock Lake, Wisconsin, USA, a small kettle lake at the modernprairie–forestecotoneintheGreatLakesRegionofNorthAmerica.Methods: We analysed a lacustrine sediment core from Comstock Lake, Wis-consin,forpaleoecologicalproxiesincludingcharcoalquantityandmorphotype,pollen composition, magnetic susceptibility, organic matter concentration andstable carbon and nitrogen isotopes. These paleoecological variables were usedto reconstruct climate-mediated shifts in vegetation, ﬁre disturbance and bio-geochemical cycling during the last 13 200 calendar years before present (cal yrBP).Results: Forest composition in the landscape surrounding Comstock Lake var-ied among coniferous forest, deciduous forest and savanna over the Holocene.Independentofthevegetationchanges,ﬁvedistinctﬁreregimeswereidentiﬁed,ranging from frequent, low-intensity surface ﬁres to infrequent, high-intensitycrown ﬁres. The main feature of our vegetation reconstruction is a shift fromPinus to Quercus forest that occurred between 10 000 and 11 000 cal yr BP.However, changes in fuel source and forest structure were apparently moreimportant than shifts of species composition in determining ﬁre regimes. Weobserved an inverse relationship between non-arboreal fuel sources and bio-mass burning throughout all ﬁve ﬁre regimes. The biogeochemical conse-quences of ﬁres were apparent during some, but not all regime transitions.Generally, the sediments were composed of relatively small clastic inputs fromthecatchmentandmostlyautochthonousorganicsources.Conclusion: The location of Comstock Lake on the prairie–forest boundarymeant that regional climate signals during the Holocene were ﬁltered throughvegetation. Both compositional changes in dominant tree taxa and structuralchangesincanopyopennessinﬂuencedﬁreregimes.IntroductionVegetation structure, community composition and fuelconditions are important determinants of wildﬁre recur-rence and ﬁre type. Increasing abundances of ﬁre-proneplant taxa can increase landscape susceptibility to burning(Brooks et al. 2004; Ohlson et al. 2011), change post-ﬁrecommunity composition (Johnstone et al. 2004; Griguliset al. 2005) and alter soil properties and biogeochemicalcycling from pre-disturbed conditions (Gillson & Ekblom
Assessment of tsunami hazard to the U.S. East Coast using relationships between submarine landslides and earthquakes

Abstract Submarine landslides along the continental slope of the U.S. Atlantic margin are potential sources for tsunamis along the U.S. East coast. The magnitude of potential tsunamis depends on the volume and location of the landslides, and tsunami frequency depends on their recurrence interval. However, the size and recurrence interval of submarine landslides along the U.S. Atlantic margin is poorly known. Well-studied landslide-generated tsunamis in other parts of the world have been shown to be associated with earthquakes. Because the size distribution and recurrence interval of earthquakes is generally better known than those for submarine landslides, we propose here to estimate the size and recurrence interval of submarine landslides from the size and recurrence interval of earthquakes in the near vicinity of the said landslides. To do so, we calculate maximum expected landslide size for a given earthquake magnitude, use recurrence interval of earthquakes to estimate recurrence interval of landslide, and assume a threshold landslide size that can generate a destructive tsunami. The maximum expected landslide size for a given earthquake magnitude is calculated in 3 ways: by slope stability analysis for catastrophic slope failure on the Atlantic continental margin, by using land-based compilation of maximum observed distance from earthquake to liquefaction, and by using land-based compilation of maximum observed area of earthquake-induced landslides. We find that the calculated distances and failure areas from the slope stability analysis is similar or slightly smaller than the maximum triggering distances and failure areas in subaerial observations. The results from all three methods compare well with the slope failure observations of the M w = 7.2, 1929 Grand Banks earthquake, the only historical tsunamigenic earthquake along the North American Atlantic margin. The results further suggest that a M w = 7.5 earthquake (the largest expected earthquake in the eastern U.S.) must be located offshore and within 100 km of the continental slope to induce a catastrophic slope failure. Thus, a repeat of the 1755 Cape Anne and 1881 Charleston earthquakes are not expected to cause landslides on the continental slope. The observed rate of seismicity offshore the U.S. Atlantic coast is very low with the exception of New England, where some microseismicity is observed. An extrapolation of annual strain rates from the Canadian Atlantic continental margin suggests that the New England margin may experience the equivalent of a magnitude 7 earthquake on average every 600–3000 yr. A minimum triggering earthquake magnitude of 5.5 is suggested for a sufficiently large submarine failure to generate a devastating tsunami and only if the epicenter is located within the continental slope.
Using link RTT to passively detect unapproved wireless nodes

Rogue Access Points (APs) produce security vulnerabilities in enterprise/campus networks by circumventing security mechanisms. We propose to use network traffic Round Trip Time (RTT) coupled with standard wireless network policies to distinguish between wired nodes, authorised APs, and rogue APs. Further, this approach has the following advantages: independent of wireless technology (802.11a/b/g); resilient to increases in capacity for wired and wireless links; scalable; resilient to effects of multiple hops; independent of rouge AP signal range. Our experimental results show that we can quickly classify the nodes as wired or wireless with 80-100% accuracy.
Current and future therapy for hereditary angioedema

Hereditary angioedema (HAE) is an autosomal dominant disease characterized by recurrent episodes of potentially life-threatening angioedema. Attacks of angioedema in HAE patients typically last 3 or more days, begin during childhood, and continue to occur throughout life. Tragically, patients with HAE continue to die as a direct consequence of the disease. Minimizing the morbidity and mortality associated with HAE requires both effective treatment of acute attacks as well as strategies to prevent HAE attacks. While there is currently no effective therapy available in the United States for the treatment of acute attacks of HAE, several molecules have demonstrated impressive efficacy in this setting, and it is likely that one or more of these new drugs will become available in the United States soon. This article will review both the current and the future therapeutic options for the treatment of HAE.
Convergence rate of Controlled Hopwise Averaging on various graphs

This paper analyzes the convergence properties of Ideal Controlled Hopwise Averaging (ICHA) and Controlled Hopwise Averaging (CHA), two recently proposed asynchronous distributed averaging algorithms for wireless networks, which were shown via simulation to be more bandwidth/energy efficient than several existing schemes. We first derive deterministic upper bounds on the exponential convergence rate of ICHA on general graphs and specific ones (i.e., path, cycle, regular, strongly regular, and complete graphs), expressing the bounds explicitly in terms of the graph invariants. We then show that such bounds of ICHA are roughly 20% better than the average-case, stochastic convergence rate of Pairwise Averaging on path, cycle, and complete graphs. Finally, we obtain upper bounds on the convergence rate of CHA with respect to iteration and time, and show that iteration-wise CHA enjoys the same bounds as ICHA, closely mimicking its behavior while being practical.
A Versatile Molecular Layer-by-Layer Thin Film Fabrication Technique Utilizing Copper(I)-Catalyzed Azide−Alkyne Cycloaddition

We have developed a rapid and versatile layer-by-layer (LbL) thin film fabrication method using copper(I)-catalyzed azide−alkyne cycloaddition (CuAAC) or “click” chemistry in the construction of molecular multilayer assemblies. Multilayers containing synthetic porphyrins, perylene diimides, and mixtures of the two have been constructed in order to highlight the versatility of this method. Characterization of thin films using UV−vis absorption, water contact angle, and electrochemical techniques indicate that multilayer growth is consistent over tens of layers. Preliminary X-ray reflectivity measurements yield an average bilayer thickness of 2.47 nm for multilayers of 1 and 3 grown on glass. Polarized absorption measurements suggest that the dense thin films exhibit moderate ordering in their molecular structure with partial alignment with respect to the surface normal.
Evolutionary designs for electric signals and electroreceptors in gymnotoid fishes of Surinam

1. Field collections of gymnotoid electric fish in coastal Surinam streams; 23 March–6 April, 1976, yielded 11 species belonging to two families (Rhamphichthyidae and Gymnotidae). Electric organ discharges (EODs) were recorded and power spectra were generated by Fourier analysis. Each species could be classified as either wave or pulse type. Although EODs varied from species to species, individuals had species-typical discharges. EODs appear to function in electrolocation and electric communication. Coexisting pulse fish diverged in either pulse spectrum or pulse repetition rate. Although each species showed ecological preferences for one habitat or another, no general correlation was found between EOD form and habitat type (Fig. 1). 2. Three species of coexisting Hypopomus showed widely differing EOD durations. Peak spectral energies were nonoverlapping (Fig. 4a). 3. Electrophysiologic studies of the electroreceptors in Hypopomus species revealed five types of electroreceptors. Two types of units appear to act as EOD filters, responding maximally to spectral frequencies characteristic of the peak power of the species-specific EOD (Fig. 7). 4. Relationships between EOD rate and spectrum are discussed with reference to their roles in communication and in electrolocation. A theory for the evolution of EOD wave forms is presented (Fig. 9).
A new Early Cretaceous coelacanth from Texas

Coelacanths have a long fossil record spanning from Early Devonian to the present globally, but until now only from Permian and Triassic sediments in Texas. Reported here is a partial skull, including an articulated lower jaw and disarticulated cranial elements, of a new coelacanth fish (Sarcopterygii: Actinistia) from the Early Cretaceous (Albian) of northern Texas. The presence of a single large pore opening for the supraorbital sensory canal, lack of ornamentation of the cheek and opercular bones, the presence of a few large pore openings in the cheekbones (five or less in the lachrymojugal, one in the other cheekbones) and the presence of small teeth are characters placing this specimen within a new clade along with the genera Libys, Ticinepomis and Diplurus. An upturned symphysis, unornamented gular plates whose posterior margins taper to points, and angular with sinuous dorsal edges reaching the same dorsal extent as the dentary are characters that make this specimen morphologically unique among the...
The action of D-amphetamine on spontaneous activity in the caudate nucleus and reticular formation of the rat.

Dextro-amphetamine sulfate injected intraperitoneally in paralyzed, locally anesthetized rats, resulted in a biphasic alteration in spontaneous activity in the caudate nucleus. An initial dose-dependent potentiation of activity occurs 510 min after injection followed by a prolonged dose-dependent depression of activity which may last as long as several hours. Similar injections result in a different time-course of alterations in the mesencephalic reticular formation consisting of a prolonged increase followed by a depression of spontaneous activity. Spontaneous activity in the caudate nucleus was relatively unaffected by mephentermine sulfate, a peripheral sympathomimetic. The depression of activity produced by amphetamine could be reversed by haloperidol, a dopaminergic blocking agent. Haloperidol injected alone produced a transient potentiation of activity followed by a return to control firing rate. These results provide electrophysiological support for the inhibitory synaptic function of dopamine in the caudate-putamen and for the alleged action of amphetamine and haloperidol at these sites. Both the differential biochemical and neurophysiological effects of amphetamine on the caudate nucleus and reticular formation may have functionally significant behavioral consequences.
Assessing the Effects of Data Selection with the DAO Physical-Space Statistical Analysis System*

Conventional optimal interpolation (OI) analysis systems solve the standard statistical analysis equations approximately, by invoking a local approximation and a data selection procedure. Although solution of the analysis equations is essentially exact in the recent generation of global spectral variational analysis systems, these new systems also include substantial changes in error covariance modeling, making it difficult to discern whether improvements in analysis and forecast quality are due to exact, global solution of the analysis equations, or to changes in error covariance modeling. The formulation and implementation of a new type of global analysis system at the Data Assimilation Office, termed the Physical-space Statistical Analysis System (PSAS), is described in this article. Since this system operates directly in physical space, it is capable of employing error covariance models identical to those of the predecessor OI system, as well as more advanced models. To focus strictly on the effect of global versus local solution of the analysis equations, a comparison between PSAS and OI analyses is carried out with both systems using identical error covariance models and identical data. Spectral decomposition of the analysis increments reveals that, relative to the PSAS increments, the OI increments have too little power at large horizontal scales and excessive power at small horizontal scales. The OI increments also display an unrealistically large ratio of divergence to vorticity. Dynamical imbalances in the OI-analyzed state can therefore be attributed in part to the approximate local method of solution, and are not entirely due to the simple geostrophic constraint built into the forecast error covariance model. Root-mean-square observation minus 6-h forecast errors in the zonal wind component are substantially smaller for the PSAS system than for the OI system.
The opposite of control: a Deweyan perspective on intrinsic motivation in “After 3” technology programs

Abstract A central feature of the design of many “After 3” technology programs is the assumption that student learning and motivation requires that they have choice and control of their activity. Similarly, the dominant cognitive-rational perspective of motivation portrays effective learners as having control of themselves and their environment. In this article, we build on Dewey's (1934. Art as experience. New York: Perigree.) aesthetics and epistemology — as most fully developed in “Art as experience” — to suggest that to be deeply engaged in learning, to be truly moved, requires not only control, but also the “opposite of control”. In “Art as experience” Dewey proposed that aesthetic experience — compelling, transformative experience — requires doing (acting on the world), reflection (standing back from the world), and undergoing (being acted upon by the world). Furthermore, grasping the meaning of these experiences emerges through a qualitative sense in addition to intentional analysis and reflection. Thus, intrinsic motivation, or what we shall call transformative experience, finds a balance between control and its opposite. We elaborate our conception of the “opposite of control” and discuss how this idea helps us appreciate heretofore unilluminated qualities of intrinsic motivation in “After 3” technology programs.
Exploring how security features affect the use of electronic health records

While individuals in most organisations routinely use computers to conduct business, few healthcare organisations have Electronic Health Record Systems (EHRS). Healthcare organisations face many obstacles and challenges when implementing EHRS including healthcare staff and physician resistance, security issues, and costs. While previous studies explored physician and healthcare organisation adoption issues, this study uses Smart PLS to explores why staff members resist EHR usage using a hybrid Technology Acceptance Model (TAM). It examines whether security measures including biometrics for authentication purposes, multiple access features provided to healthcare provider, and use of Single Sign-On (SSO) systems influences these individual's attitude toward EHRS.
Oral Absorption Efficiency of Acid-Labile Antibiotics from Lipid-Drug Delivery Systems

The utility of cholesterol, cholesteryl acetate, and β-sitosterol in protecting and improving the oral absorption efficiency of acid-labile antibiotics is discussed. The potassium salts of penicillin G and penicillin V and erythromycin lactobionate were studied. The stability of the two penicillins in simulated gastric fluid was determined iodometrically. The rank order of acid protective activity was: cholesteryl acetate > β-sitosterol > cholesterol. Oral administration of erythromycin lactobionate coated with cholesteryl acetate produced a twofold increase in human urinary excretion of erythromycin when compared with the uncoated material. Potassium salts of penicillin G and penicillin V coated with cholesteryl acetate yielded 1.6- and 2-fold higher urine levels, respectively, as compared with the uncoated candidates.
Probing Cellular Chemistry in Biological Systems with Microelectrodes

Over the past 20 years, the technological impediments to fabricating electrodes of micrometer dimensions have been largely overcome. These small electrodes can be readily applied to probe chemical events at the surface of tissues or individual biological cells; they can even be used to monitor concentration changes within intact animals. These measurements can be made on rapid time scales and with minimal perturbation of the system under study. Several recent applications have provided important insights into chemical processes at cells and in tissues. Examples include molecular flux measurements at the surface of single cells and through skin-which can offer insights into oxidative stress, exocytosis, and drug delivery-and real-time brain neurotransmitter monitoring in living rats, which reveals correlations between behavior and molecular events in the brain. Such findings can promote interdisciplinary collaborations and may lead to a broader understanding of the chemical aspects of biology.
Highly efficient gene transfer into adult ventricular myocytes by recombinant adenovirus.

Abstract Molecular dissection of mechanisms that govern the differentiated cardiac phenotype has, for cogent technical reasons, largely been undertaken to date in neonatal ventricular myocytes. To circumvent expected limitations of other methods, the present study was initiated to determine whether replication-deficient adenovirus would enable efficient gene transfer to adult cardiac cells in culture. Adult rat ventricular myocytes were infected, 24 h after plating, with adenovirus type 5 containing a cytomegalovirus immediate-early promoter-driven lacZ reporter gene and were assayed for the presence of beta-galactosidase 48 h after infection. The frequency of lacZ+ rod-shaped myocytes was half-maximal at 4 x 10(5) plaque-forming units (PFU) and approached 90% at 1 x 10(8) PFU. Uninfected cells and cells infected with lacZ- virus remained colorless. Beta-galactosidase activity concurred with the proportion of lacZ+ cells and was contingent on the exogenous lacZ gene. At 10(8) PFU/dish, cell number, morphology, and viability each were comparable to uninfected cells. Thus, adult ventricular myocytes are amenable to efficient gene transfer with recombinant adenovirus. The relative uniformity for gene transfer by adenovirus should facilitate tests to determine the impact of putative regulators upon the endogenous genes and gene products of virally modified adult ventricular muscle cells.
Inanimate environmental enrichment for group-housed rhesus macaque infants.

The behavior of peer-reared infant rhesus macaques raised in enriched and nonenriched housing conditions was examined in order to evaluate the utility and effectiveness of object enrichment in a group housing setting. Environmental enrichment consisted of apparatuses designed to promote motor activity and to provide response-contingent feedback. Four animals in each condition were tested over a 14-month period. Behavioral observations were conducted in the home cage and during several test situations specifically designed to assess behavioral and affective responses to novelty and mild stressors. Monkeys in the enriched condition exhibited fewer behavioral and affective signs of disturbance than control infants in all observation conditions.
Influence of deacetylation on the rheological properties of xanthan-guar interactions in dilute aqueous solutions.

ABSITRACT: An oscillating capillary rheometer was used to investigate the effects of xanthan deacetylation on the -3 viscoelastic properties and intrinsic viscosity of xanthan and guar niktures in dilute aqueous solutions. Deacetylated xanthan exhibited a stronger synergistic interaction with guar than native zanthan did due to the destabilized helical structure and increased chaln flexibility of the deacetylated zanthan. No gels were obsersed for all xanthan-guar mixtures. Native xanthan-guar mixtures exhibited a llqnid-like behavior whereas deacetylated xanthanar mixtures exhibfted a gel-like behavior. The relative viscosity and elasticity of deacetylated xanthan-guar mixtures were much stronger than those for native lanthan-guar mixtures. The intrinsic viscosities of deacetylated ianthan-guar mixtures were higher than the calculated values assuming no interaction, whereas the intrinsic viscosities of native zanthan-guar mixtures were lower than the calculated values assuming no interaction, demonstrating that inter-molecular binding occurred between the disordered segments of xanthan and guar gum in dilute aqueous solutions.
School Choice and the Challenges that Remain: A Comment on Richard D. Komer's “School Choice and State Constitutions' Religion Clauses”

Richard Komer's paper helpfully and carefully shows that, after the Supreme Court's 2002 ruling in Zelman v. Simmons-Harris, a formidable obstacle to choice-based educational reform has been removed, and also that other, no-less-formidable obstacles remain, in the form of anti-aid provisions contained in various states' own constitutions. This brief, appreciative Comment notes, first, that uncertainties remain about the implementation and interpretation of Zelman, and even—considering the possibility of new appointments to the Court—the decision's fate. Next, and moving beyond the Court's First Amendment doctrine, this Comment suggests that the effort to implement choice-based educational reform is, and will remain, as much a political fight as a legal one. Finally, it emphasizes that real choice-based reform depends on there being real choices. For choice-based reform to get off the ground, there need to be plausible, solvent, qualified, educationally sound, and attractive private options available. More...
Cutting Edge: A Role for Inside-Out Signaling in TCR Regulation of CD28 Ligand Binding

Efficient T cell activation depends on the engagement of both TCR and CD28, although the molecular mechanisms that control this signal integration are not fully understood. Using fluorescence resonance energy transfer, we show that T cell activation can drive a reorientation of the cytosolic tails of the CD28 dimer. However, this is not mediated through CD28 ligand binding. Rather, TCR signaling itself mediates this conformation change in CD28. We also show that TCR signaling can induce CD28–ligand interactions. Although the CD28 dimer appears to bind ligand monovalently in solution, we show that both ligand binding sites are required to efficiently recruit CD28 to the immunological synapse. These results suggest, that analogous to the cross-talk from TCR that regulates integrin activation, TCR-initiated inside-out signaling may induce a conformational change to the extracellular domains of CD28, enabling ligand binding and initiating CD28 signaling.
Imaging Molecular Pathways: Reporter Genes

Molecular imaging is a rapidly advancing field that allows cancer biologists to look deeper into the complex inner workings of tumor cells, or whole tumors, in a non-invasive manner. In this review, we will summarize some recent advances that enable investigators to study various important biological processes in tumors in vivo. We will discuss novel imaging approaches that allow investigators to visualize and quantify molecular pathways, such as receptor tyrosine kinase activation, hypoxia signal transduction, apoptosis, and DNA double-strand breaks. Select examples of these applications will be discussed. Because of the limited scope of this review, we will only focus on natural reporters, such as bioluminescence and fluorescent proteins.
Reproductive biology of a North American subalpine plant: Corydalis caseana A. Gray ssp. brandegei (S. Watson) G. B. Ownbey

Corydalis caseana ssp. brandegei (Fumariaceae) is a perennial plant that grows in moist, subalpine regions of south central Colorado, USA. Prior to this study, nothing was known of its reproductive biology. The most numerous visitors (59%), and the only known pollinators, were long-tongued bumblebees (Bombus appositus). Twenty-nine percent of visits were from short-tongued nectar-robbing bumblebees (Bombus occidentalis). Hummingbirds also visited the flowers but they did not pollinate them. Corydalis caseana flowers remained open and in good condition for approximately 4 days. During that time, in the absence of visitors, nectar containing 35% sugar accumulated at a rate of approximately 1 mL per day. Corydalis caseana has a mixed-mating system. It is self-fertile, but the self-fertilized flowers produce fewer seeds per fruit than the outcrossed flowers (a mean of 2.9 compared with a mean of 4.7). Results suggest a possibility of inbreeding depression.
The effect of multipath fading on the radiometric detection of frequency hopped signals

The effect of fading due to multipath is seldom accounted for in the assessment of the vulnerability of frequency hopped communications systems to radiometric intercept threats. However, the results derived in the paper illustrate that fading due to multipath could significantly improve the ability of a radiometer to detect frequency hopped signals transmitted at sea. >
Relationship of high tissue concentrations of azithromycin to bactericidal activity and efficacy in vivo

Measurement of killing kinetics of azithromycin against strains of Streptococcus pneumoniae and Klebsiella pneumoniae in vitro showed that it had a limited bactericidal activity (greater than 90% kill) for the first eight hours of incubation, but developed complete bactericidal activity (greater than 99.9% kill) by 24 h incubation. Since high and sustained tissue levels of azithromycin occur in animals and humans, it was proposed that it might produce a bactericidal effect in vivo. This was demonstrated in a lung infection model in mice, designed to mimic the in-vitro killing studies. A 25 mg/kg dose of azithromycin given 24 h before intranasal challenge reduced the recoverable Str. pneumoniae population by greater than 99.9%, in comparison with untreated controls. Erythromycin did not produce a bactericidal effect at 100 mg/kg, and roxithromycin only reduced the viable count by 96%, at a dose of 50 mg/kg. Against a K. pneumoniae lung infection, a 50 mg/kg dose of azithromycin reduced the bacterial count by 99%. The bactericidal effect was correlated with lung tissue concentrations of azithromycin. In a proliferating Escherichia coli paper disc infection model, extravascular fluid concentrations of azithromycin were correlated with a 99.9% reduction in bacterial count, while corresponding serum concentrations were always less than the MIC. Dosing with azithromycin eradicated Haemophilus influenzae from the bulla (middle ear) of gerbils, as was not the case with erythromycin and roxithromycin. This effect was correlated with the antibiotic concentration in bulla lavage.
A discussion on the feasibility of a transmission-line analog for crossed-field nonuniform drifting electron beams

It is shown that, under certain assumptions, a lossless transmission-line analog does not exist for the case of a drifting, nonuniform, crossed-field beam.
High-precision, programmable 1-10 MHz bandwidth, 0-20 dB gain communication channel for digital video applications

The analog signal processing portion of a digital video demodulation scheme is built in a 5 V BiCMOS process. The channel is both cutoff frequency and gain programmable from 1/spl rarr/10 MHz and 0/spl rarr/20 dB, respectively. The filter is realized as a 4/sup th/ order Gm/C Butterworth lowpass and includes in-package trim for accurate control. A programmable gain amplifier is placed in front of the filter for better S/N performance (>40 dB) and lower intermodulation distortion (>-52 dB). The PSRR of this single-ended channel is better than 40 dB. The channel dissipates 250 mW.
Enrollment of Elderly Patients in Clinical Trials for Cancer Drug Registration: A 7-Year Experience by the US Food and Drug Administration

Purpose To analyze the age-related enrollment of cancer patients onto registration trials of new drugs or new indications approved by the US Food and Drug Administration from 1995 to 2002. Patients and Methods This study involved retrospective analyses of demographic data of cancer patients enrolled onto registration trials. The data on 28,766 cancer patients from 55 registration trials were analyzed according to age distributions of ≥ 65, ≥ 70, and ≥ 75 years. The rates of enrollment in each age group for each cancer were compared with the corresponding rates in the US cancer population. The age distributions of the US cancer population were derived from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute for the period 1995 to 1999 based on the 2000 US Census. Results The proportions of the overall patient populations aged ≥ 65, ≥ 70, and ≥ 75 years were 36%, 20%, and 9% compared with 60%, 46%, and 31%, respectively, in the US cancer population. Statistically signifi...
The Eigentrust algorithm for reputation management in P2P networks

Peer-to-peer file-sharing networks are currently receiving much attention as a means of sharing and distributing information. However, as recent experience shows, the anonymous, open nature of these networks offers an almost ideal environment for the spread of self-replicating inauthentic files.We describe an algorithm to decrease the number of downloads of inauthentic files in a peer-to-peer file-sharing network that assigns each peer a unique global trust value, based on the peer's history of uploads. We present a distributed and secure method to compute global trust values, based on Power iteration. By having peers use these global trust values to choose the peers from whom they download, the network effectively identifies malicious peers and isolates them from the network.In simulations, this reputation system, called EigenTrust, has been shown to significantly decrease the number of inauthentic files on the network, even under a variety of conditions where malicious peers cooperate in an attempt to deliberately subvert the system.
A 4-channel wearable wireless neural recording system

This paper presents a 4-channel wearable wireless neural recording system that consists of wireless head stage, receiver board, and user interface software. The wireless head stage is implemented using a custom designed font-end IC for bio potential amplification, filtering, and channel selection and a commercial analog FM transmitter chip. Adjustable gain and bandwidth of the channel allows the system to be used in recording various neural signals. The size of the head stage is 1.55" times 1.725" times 0.5" and the weight is 20 g. The power consumption of the head stage is 28 mW from two 1.55 V button cell batteries that allows continuous operation of at least 15 hours. The system was tested for ex-vivo and in-vivo extracellular recordings from a dissected snail brain and a live rat respectively.
Faculty development in emergency medicine

Faculty development is an important, multifaceted topic in academic medicine. In this article, academic emergency physicians discuss aspects of faculty development, including: 1) a department chair's method for developing individual faculty members, 2) the traditional university approach to promotion and tenure, 3) faculty development in a new department, and 4) personal development.
Quantum theory of 1/f noise in quantum well photodetectors

The quantum theory of 1/f noise describes the infrared-divergent conventional 1/f fluctuations of quantum mechanical cross sections and process rates by simple, universal, formulas. We calculate the ones that affect the dark current in quantum wells, and compare with known experimental results.
Unique Counting Call of a Katydid, Scudderia pistillata (Orthoptera: Tettigoniidae: Phaneropterinae)

ABSTRACT The katydid Scudderia pistillata Brunner, 1878 (Orthoptera: Tettigoniidae: Phaneropterinae), is anecdotally called the “counting katydid” because the syllables produced from each wing closure of the male calling song are grouped into phrases, with each successive phrase in the first seven phrases of a calling bout typically possessing one more syllable than the previous phrase. Analysis of >500 recorded male bouts showed that adding syllables to each phrase is stereotypic for the species. Although this aspect of the calls was stereotypical, other aspects of the calls exhibited variability, including the total numbers of syllables and phrases per bout, which were correlated with a male's nutritional condition, as indexed by residual weight. Potential behavioral functions of the counting sequence are discussed.
Photographic measures of cytomegalovirus retinitis as surrogates for visual outcomes in treated patients.

Objective To evaluate photographic measures of cytomegalovirus (CMV) retinitis as surrogate outcomes for changes in vision in patients with CMV retinitis related to the acquired immunodefiency syndrome. Methods Data from 3 clinical trials of CMV retinitis treatments were analyzed. Two photographic assessments of retinitis in eyes involved at baseline were evaluated: progression (lesion border movement ≥750 µm or occurrence of a new lesion) and change in area of retina involved with retinitis. Vision measures were decline in best-corrected visual acuity and change in visual field. Photographic measures were evaluated as surrogate outcomes based on 4 criteria: (1) association with vision measure; (2) ability to account for treatment-related differences in vision measure; (3) data completeness; and(4) sample size requirements. Results Data from 1001 involved eyes (666 patients) were analyzed. Progression and change in area involved were predictive of declines in vision measures, accounted for 50% and 66% of the treatment effect on visual field, and were available from 93% and 64% of involved eyes, respectively. Sample size estimates for a clinical trial were smallest with progression as the design outcome. Conclusion Progression and change in area involved met the first and second criteria for surrogate outcomes for visual field loss; a complete evaluation for visual acuity decline was not possible because treatment-related differences were not observed. Progression met the logistical and sample size criteria better than change in area of retina involved with retinitis.
Non-Human Life and the Boundaries of Community

Once upon a time a young man was walking through the woods on his way home from the market. In his pack he carried vegetables, fruits, and bread for his family. Wandering down the path and approaching a clearing, he happened to smell smoke. A quick investigation uncovered a bush overcome by low flames that were growing higher, and from the middle of the bush an adder called out for assistance. Tying one of the bread sacks to his staff and reaching it into the flames, the young man called to the adder to slip inside the sack and be lifted to safety. The adder complied and was saved. Away from danger the adder expressed his happiness and explained that some travelers had kindled the fire a few minutes before. The young man, pleased with himself after saving the adder and then putting out the fire, prepared to go on his way and suggested that the adder go in peace now and no longer harm men since he owed his life to a man’s kindness. The adder, though, turned to strike him.
Landscape genomic analysis of candidate genes for climate adaptation in a California endemic oak, Quercus lobata

PREMISE OF THE STUDY The ability of California tree populations to survive anthropogenic climate change will be shaped by the geographic structure of adaptive genetic variation. Our goal is to test whether climate-associated candidate genes show evidence of spatially divergent selection in natural populations of valley oak, Quercus lobata, as preliminary indication of local adaptation. METHODS Using DNA from 45 individuals from 13 localities across the species' range, we sequenced portions of 40 candidate genes related to budburst/flowering, growth, osmotic stress, and temperature stress. Using 195 single nucleotide polymorphisms (SNPs), we estimated genetic differentiation across populations and correlated allele frequencies with climate gradients using single-locus and multivariate models. RESULTS The top 5% of FST estimates ranged from 0.25 to 0.68, yielding loci potentially under spatially divergent selection. Environmental analyses of SNP frequencies with climate gradients revealed three significantly correlated SNPs within budburst/flowering genes and two SNPs within temperature stress genes with mean annual precipitation, after controlling for multiple testing. A redundancy model showed a significant association between SNPs and climate variables and revealed a similar set of SNPs with high loadings on the first axis. In the RDA, climate accounted for 67% of the explained variation, when holding climate constant, in contrast to a putatively neutral SSR data set where climate accounted for only 33%. CONCLUSIONS Population differentiation and geographic gradients of allele frequencies in climate-associated functional genes in Q. lobata provide initial evidence of adaptive genetic variation and background for predicting population response to climate change.
Bacterial Habitats in Extreme Environments

As our knowledge of prokaryotic diversity has increased so has our understanding of microbial habitats. Indeed, it has become clear in recent years that few natural habitats on Earth are sterile and that most habitats contain a great diversity of microorganisms, especially of prokaryotes (Bacteria and Archaea). When considering microbial habitats one should also recall the concept of the “microenvironment” (Madigan et al., 2000). Although habitats themselves can vary dramatically, for example, lake water and soil, conditions within any given habitat can also vary in both a spatial and temporal context. In fact, it is likely that the great physiological and phylogenetic diversity of prokaryotes we see today is the result of evolutionary pressure on these organisms to colonize every habitat and every microenvironment within each habitat that will support life.
GRPR-targeted Protein Contrast Agents for Molecular Imaging of Receptor Expression in Cancers by MRI.

Gastrin-releasing peptide receptor (GRPR) is differentially expressed on the surfaces of various diseased cells, including prostate and lung cancer. However, monitoring temporal and spatial expression of GRPR in vivo by clinical MRI is severely hampered by the lack of contrast agents with high relaxivity, targeting capability and tumor penetration. Here, we report the development of a GRPR-targeted MRI contrast agent by grafting the GRPR targeting moiety into a scaffold protein with a designed Gd(3+) binding site (ProCA1.GRPR). In addition to its strong binding affinity for GRPR (Kd = 2.7 nM), ProCA1.GRPR has high relaxivity (r1 = 42.0 mM(-1)s(-1) at 1.5 T and 25 °C) and strong Gd(3+) selectivity over physiological metal ions. ProCA1.GRPR enables in vivo detection of GRPR expression and spatial distribution in both PC3 and H441 tumors in mice using MRI. ProCA1.GRPR is expected to have important preclinical and clinical implications for the early detection of cancer and for monitoring treatment effects.
Ergonomic design and analysis for portable assisted mobilization devices

ABSTRACTThe purpose of this investigation is to propose a novel approach for the assessment of ergonomics in the design of mobility devices targeted towards the 5th and 95th percentiles in size dimensions of the Brazilian population. The method delivers the optimal ergonomic specifications that eliminate injury risk, provide comfort, and reduce fatigue of users operating a mobility device in a high-density metropolis. These ranges and measurements have undergone a feasibility assessment with the use of Tecnomatix Jack software and the building of a prototype. The ergonomic design characteristics have been analyzed with a Quality Function Deployment (QFD) Matrix to evaluate their impact in the overall device's design and feasibility solutions have been generated with the use of the Theory of Inventive Problem Solving (TRIZ).
Studies on factor VIII activation potential in hemophilia A-plasma and its significance for the comprehension of hemophilia.

In a factor VIII exchange test experiment higher factor VIII activities are measurable than would be expected from the single activities of the used plasmas. The same goes for the use of plasmas from carriers of hemophilia A, but not for plasmas from patients with v. W.J.S. (von-Willebrand Jurgens syndrome). In plasmas from hemophilic adults activation obviously proceeds at a slower rate than in plasmas from hemophilic children.
Political Science and the Jews: A Review Essay on the Holocaust, the State of Israel, and the Comparative Analysis of Jewish Communities

The Jewish State: A Century Later. By Alan Dowty. Berkeley: University of California Press, 1998. 337p. $35.00. Comparing Jewish Societies. Edited by Todd M. Endelman. Ann Arbor: University of Michigan Press. The Comparative Studies in Society and History Book Series. 369p. $22.95. Rubber Bullets: Power and Conscience in Modern Israel. By Yaron Ezrahi. New York: Farrar, Straus, and Giroux. 307p. $25. Berkeley: University of California Press, 1998. 307p. $16.95. Jews and the New American Scene. By Seymour Martin Lipset and Earl Raab. Cambridge, MA: Harvard University Press, 1995. 239p. $22.95. Palestinian Citizens in an Ethnic Jewish State: Identities in Conflict. By Nadim N. Rouhana. New Haven, CT: Yale University Press, 1997. 332p. $30.00. The Order of Terror: The Concentration Camp. By Wolfgang Sofsky. Trans. William Templer. Princeton, NJ: Princeton University Press, 1997. 353p. $29.95. The Founding Myths of Israel. By Zeev Sternhell. Trans. David Maisel. Princeton, NJ: Princeton University Press, 1997. 419p. $29.95.
Alteration of Lipid Metabolism in Japanese Quail by Feeding Oat Hulls and Brans

Abstract Five varieties of oat brans fed for 4 weeks at 2.27% and oat hulls fed at 11.36% in a semi-purified diet containing .5% cholesterol were ineffective in lowering cholesterol levels in the serum of 5-week-old Japanese quail. Oat brans and hulls reduced the level of fat in livers of both males and females. No differences in cholesterol levels were observed between sexes, but hypertriglyceridemia and high liver fat contents were more evident in females. This may be the result of sexual maturation stimulated by a 14L:10D photoperiod.