cssi/SciSciGPT-SciSciNet huggingface dataset:
Suppression of methanogenesis by dissimilatory Fe(III)‐reducing bacteria in tropical rain forest soils: implications for ecosystem methane flux

Tropical forests are an important source of atmospheric methane (CH 4 ), and recent work suggests that CH 4 fluxes from humid tropical environments are driven by variations in CH 4 production, rather than by bacterial CH 4 oxidation. Competition for acetate between methanogenic archaea and Fe(III)-reducing bacteria is one of the principal controls on CH4 flux in many Fe-rich anoxic environments. Upland humid tropical forests are also abundant in Fe and are characterized by high organic matter inputs, steep soil oxygen (O 2 ) gradients, and fluctuating redox conditions, yielding concomitant methanogenesis and bacterial Fe(III) reduction. However, whether Fe(III)-reducing bacteria coexist with methanogens or competitively suppress methanogenic acetate use in wet tropical soils is uncertain. To address this question, we conducted a process-based laboratory experiment to determine if competition for acetate between methanogens and Fe(III)-reducing bacteria influenced CH 4 production and C isotope composition in humid tropical forest soils. We collected soils from a poor to moderately drained upland rain forest and incubated them with combinations of 13 C-bicarbonate, 13 C-methyl labeled acetate ( 13 CH 3 COO - ), poorly crystalline Fe(III), or fluoroacetate. CH 4 production showed a greater proportional increase than Fe 2+ production after competition for acetate was alleviated, suggesting that Fe(III)-reducing bacteria were suppressing methanogenesis. Methanogenesis increased by approximately 67 times while Fe 2+ production only doubled after the addition of 13 CH 3 COO - . Large increases in both CH 4 and Fe 2+ production also indicate that the two process were acetate limited, suggesting that acetate may be a key substrate for anoxic carbon (C) metabolism in humid tropical forest soils. C isotope analysis suggests that competition for acetate was not the only factor driving CH 4 production, as 13 C partitioning did not vary significantly between 13 CH 3 COO - and 13 CH 3 COO - + Fe(III) treatments. This suggests that dissimilatory Fe(III)-reduction suppressed both hydrogenotrophic and aceticlastic methanogenesis. These findings have implications for understanding the CH 4 biogeochemistry of highly weathered wet tropical soils, where CH 4 efflux is driven largely by CH4 production.
Monolithic microprocessor and RF transceiver in 0.25-micron FDSOI CMOS

A monolithic RFIC in 0.25-micron fully-depleted SOI CMOS has been designed consisting of a microcoded 8-bit 33-MHz microprocessor, a 400-MHz 8-bit ASK-modulated RF transceiver and two integrated dc-dc voltage converters for power management. This architecture exploits a low-power (sub 2-V) digital process for mixed-signal VLSI in a die size measuring 2.2 mm/spl times/2.2 mm.
Knowing and Saying that I Know

Of course there's every difference in the world between my merely saying something and its being so. My claim that I have a toothache is a far cry from the toothache itself. Words are not things: I neither sit in the word ‘chair’ nor eat the word ‘food.’
Partitionings of a genus of quadratic forms

Abstract A description of the quasigenus, which was introduced into the theory of integral quadratic forms by B. W. Jones, is given in terms of the general theory of spinor general of lattices over Dedekind domains. As a consequence several questions raised by Jones regarding the relationship between the partitionings of a genus induced by the splittings into spinor genera and quasigenera are answered.
Conduction properties of lightly doped, polycrystalline silicon

Abstract A hyperbolic-sine relationship describing the current-voltage characteristics of lightly-doped, n -type polycrystalline silicon films is derived. The derivation is based on a previous model which assumes that electron-trapping states exist at the grain boundaries of the polycrystalline film. The trapped electrons cause a surface-depletion zone and a potential barrier at each grain boundary. Electrons are transported over the barriers by thermionic emission. Conduction measurements carried out on commercially prepared samples are in good agreement with the theory developed both in voltage and temperature dependence. The model parameters obtained from conduction measurements correspond reasonably well with values inferred from scanning electron micrographs.
The top quark mass from weak boson masses without neutral currents

Abstract We present a detailed study of the indirect determination of the top quark mass from the muon lifetime calculated in the one-loop-corrected electroweak model. We use on-mass-shell renormalization, a scheme which optimally exploits the improved determinations of the weak boson masses in collider experiments. Strong interaction ambiguities, such as those associated with structure functions in calculations based on neutral current data, are essentially avoided. Limits on the top mass using present experimental errors on Mw and Mz are already competitive with those obtained from traditional neutral current analyses. We manage to parametrize our analysis in terms of a few parameters, making possible its immediate application to future experiments improving on W and Z mass measurements.
Malyngamide 2, an Oxidized Lipopeptide with Nitric Oxide Inhibiting Activity from a Papua New Guinea Marine Cyanobacterium

A Papua New Guinea collection of the marine cyanobacterium cf. Lyngbya sordida yielded three known compounds as well as a new PKS-NRPS-derived malyngamide with anti-inflammatory and cytotoxic activity. Malyngamide 2 features an extensively oxidized cyclohexanone ring. Resolution of the ring core as a 6,8,9-triol rather then a 7,8,9-triol and relative configuration was based on chemical shift and bond geometry modeling in conjunction with homonuclear and heteronuclear coupling constants, NOE and ROE correlations, and other structural information. Malyngamide 2 exhibited anti-inflammatory activity in LPS-induced RAW macrophage cells (IC50 = 8.0 μM) with only modest cytotoxicity to the mammalian cell line.
Design and Development of Water-Soluble Curcumin Conjugates as Potential Anticancer Agents

Conjugates of curcumin to two differently sized poly(ethylene glycol) molecules were synthesized in an attempt to overcome the low aqueous solubility of this natural product with cytotoxic activity against some human cancer cell lines. The soluble conjugates exhibited enhanced cytotoxicity as compared to that of the parent drug. Synthesis, analyses of the rate of drug release, and cytotoxicity studies are herein reported. The water-soluble conjugates may provide information useful for the development of injectable curcumin conjugates.
Evolving coordination schemes in real-time production scheduling☆☆☆

Abstract In the recent past, several algorithms have emerged for real-time production scheduling which are typically based upon one or more of the following techniques: integer programming, artificial intelligence/heuristic, and single trial simulations. A critical assumption in nearly every application of the above methodologies is that both processing outcomes and durations are deterministic. Real world manufacturing systems are characterized by three primary types of uncertainties. The first type of uncertainty arises from the decomposition of the overall manufacturing problem. Specifically, the real-time production scheduler must be integrated with other manufacturing functions, particularly production planning and process coordination/control. The latter functions possess detailed information that is beyond the scope of direct consideration by the real-time scheduler, yet the actions of the other functions do influence the production scheduling problem. The second source of uncertainty arises from our inability to precisely specify the constraints associated with the decision-making. The final source of uncertainty pertains to the stochastic nature of the manufacturing process. Davis and Jones [1] have developed a realtime production scheduler which will permit existing scheduling technologies to interact with other functional entities within the manufacturing system. This paper will concentrate upon the evolving coordination schemes that will be implemented within the proposed algorithm. In particular, the consequences derived from the consideration of multiple-criteria decision-making within a manufacturing hierarchy will be explored. Methodologies to address all forms of uncertainty will be discussed. Finally, the experimental testing of the coordinating procedures using hierarchical simulation will be outlined.
The effect of technical and purified pentachlorophenol on the rat liver.

Abstract Dietary concentrations of 0, 20, 100, and 500 ppm of technical grade pentachlorophenol were fed to male and female Sherman strain rats for 8 months. The same experiment using purified pentachlorophenol was carried out. The food consumption was measured in all rats during the second week of exposure and for one week every 6 weeks thereafter. An autopsy was performed on all rats at the end of the experiment. The brain, lungs, spleen, liver, kidneys, heart, and testes were weighed and examined grossly and microscopically in all rats fed purified pentachlorophenol, all female rats fed technical pentachlorophenol, and in the male rats fed the highest dose of technical pentachlorophenol and the controls. Only the kidneys and livers were examined microscopically in the male rats fed 20 and 100 ppm of technical pentachlorophenol. Although the food intake was comparable, male and female rats fed 500 ppm of technical and male rats fed 500 ppm of purified pentachlorophenol gained less weight. The livers of the male and female rats fed 500 ppm technical pentachlorophenol weighed significantly more than those of the controls. The kidneys of all male rats fed purified pentachlorophenol weighed significantly more than those of the controls; however, there was no dose-related increase. No morphological changes were seen in the kidneys. At the 500-ppm dietary concentrations, technical pentachlorophenol produced a severe effect in the liver of female rats characterized by vacuolation of the hepatocytes, an increase in fibroblasts and other mononuclear cells within sinusoids, bile duct proliferation, periportal fibrosis, degenerated liver cells, increased mitotic figures, and an accumulation of brown pigment in macrophages and in Kupffer cells. In male rats at the 100- or 500-ppm dietary concentrations of technical pentachlorophenol, the predominant lesion consisted of enlarged pleomorphic hepatocytes which had foamy cytoplasm or cytoplasm with large vacuoles. The walls of the hepatic central veins of the livers in animals of both sexes were thickened. At the 100-ppm dietary concentrations similar but less pronounced effects were observed in the livers. Only mild alterations were noted at the 20-ppm dietary concentration. Purified pentachlorophenol caused slightly enlarged liver cells with occasional eosinophilic cytoplasmic inclusions at 500 ppm but no alterations were observed in the livers of rats fed the 100- and 20-ppm dietary concentrations. The results suggest that most of the toxicity associated with feeding technical grade pentachlorophenol to rats at these dietary concentrations stems from toxic contaminants rather than from pentachlorophenol.
Maximizing dye fluorescence via incorporation of metallic nanoparticles in solution

ABSTRACT Gram-negative bacteria initiate a stress response in which the cells efflux potassium when electrophilic toxins are introduced into their environment. Hence, measurement of K + concentration in the surrounding water using a fluorescence-based potassium-selective optode has been proposed for environmental and homeland security applications. Unfortunately, the fluorophore commonly used in such an optode is inefficient. Surface enhanced fluorescence (SEF) can be used to increase its fluorescence efficiency, which will improve the sensors performance. To understand this phenomenon before applying it to the optode system, Rose Bengal (RB), an inexpensive and well characterized dye, in solution with gold and silver nanoparticles was studied. As expected, fluorescence from RB-gold solutions was low since alignment of golds surface plasmon resonance (SPR) peak and absorption and fluorescence energies in RB favored energy transfer from RB to the gold nanoparticles. The alignment of the silvers SPR peak and the RB transitions favored transfer from silver to RB. SEF was observed in solutions with large dye-to-silver separation. However, little fluorescence was observed when the solution was pumped at the silvers SPR peak. Fluorescence from the dye decreased as dye-to-silver separation decreased. An explanation for these observations is presented; additional research is needed to develop a complete understanding. Keywords: Surface enhanced fluorescence, surface plasmon, nanoparticles, colloids, gold, silver, Rose Bengal
Spectral characterization of suspended sediments generated from two texture classes of clay soil

Abstract Using natural sunlight and a wide range of suspended sediment concentrations, this research examined surface spectral responses to various concentrations of suspended sediments with different textures. Reflectivities at each of 170 individual channels between 400 and 900 nm, as well as the relationship between the integral of reflectance and the suspended sediment concentrations (SSC), were analysed. The results showed that as SSC increased, the reflectance from the finer soil increased faster than that from the coarser soil. The overall correlation between SSC and reflectance for the finer soil was higher than the one for the coarser soil. As SSC increased, the peak-reflectance wavelength of both sediments shifted toward longer wavelengths. The coarser soil suffered an early shift at 250mgl− while the finer soil experienced the shift later at 500mgl-1. Finally, the integral of reflectance at 800-900 nm interval was found to be useful for the estimation of SSC.
The Place of Words

These 24 essays offer a diverse sample of place-based ecocriticism and its approaches to writing, reading, teaching, and understanding literature and science.
The World Bank and the environment: The World Development Report 1992

Abstract Despite its biases toward “market friendliness,” the World Bank's latest World Development Report on the whole gives a sympathetic review of the environmental difficulties confronting developing countries. The Bank's preferred market-based policies, however, will not be able to resolve these problems fully, and it is by no means certain that funding for required investments and development of new technologies will be at hand.
Children with hepatitis C

Hepatitis C affects thousands of children throughout the world. Most children acquire the virus through vertical transmission, although parenteral routes of acquisition are also common. Hepatitis C progresses slowly, with mild biopsy findings and no symptoms in most children and in many adults. However, significant liver inflammation and fibrosis can occur in childhood. Trials of antiviral therapy with interferon and ribavirin have shown these drugs to be effective in almost half of the children treated. Children tend to tolerate therapy well. Further research on the natural history and treatment of hepatitis C in children is needed because the infection can have serious long-term consequences, including end-stage liver disease and hepatocellular carcinoma.
Structural investigation of the initial interface region formed by thin zirconium films on silicon (111)

A structural study of the initial interface region formed by zirconium on silicon (111) was undertaken. Thin films (100 A) of zirconium were deposited in ultrahigh‐vacuum conditions onto atomically, clean silicon (111) wafers and annealed in situ at 25 °C intervals between 300 and 425 °C, over which range Auger spectroscopy indicated silicon diffusion to the surface. Structural characterization of the evolving interface was performed primarily via extended x‐ray‐absorption fine‐structure (EXAFS) measurements. Results indicate that a major structural rearrangement takes place between 350 and 375 °C. EXAFS fitting analysis reveals this transition to be from a disordered‐intermixed phase to a more ordered state having interatomic distances closely resembling those of ZrSi, but lower coordination numbers. Ordering continues with progressively higher annealing temperatures until the interface region assumes the ZrSi structure at ∼425 °C. The results are discussed in terms of the free energy and strain of the i...
Povidone iodine as a cause of factitious hematuria and abnormal urine coloration in the pediatric emergency department

The observation of a cola-colored dipstick positive for "hematuria" was made in an 11-year-old black male who presented to the emergency department with a chief complaint of dysuria. Thorough questioning eventually revealed the source of these two abnormalities to be the addition of povidone iodine to the urine sample. The reported causes of abnormal urine coloration and of false positive dipstick hematuria are summarized.
Child Development and the Social Demography of Childhood.

This article provides background information and a practical guide for including demographic information in developmental research. First, it portrays historic demographic trends reflecting critical ways in which the family and economic environments of children have been, and continue to be, transformed in the United States. Second, it presents current demographic statistics to provide a basis for researchers to compare their special study populations to the general population of children and to formulate specific hypotheses about ways in which their results might differ for children in various demographic situations. Third, it offers an Appendix with standardized wording for a minimum set of questions needed to measure the demographic characteristics and environments of children. The Appendix provides researchers the technical capacity to collect such data, so they can develop and test hypotheses about how family and economic environments shape child development processes and outcomes.
Abstract C50: Novel silicon derivatives of indomethacin: Generation of potent COX‐2 selective agents with improved anticancer activity

Elevated tumor cyclooxygenase‐2 is associated with poor overall survival in patients with a variety of cancers. Patients with elevated COX‐2 that receive a COX‐2 inhibitor have demonstrated improved survival. Indomethacin (IM) is a COX‐non‐selective inhibitor with demonstrated anticancer activity in patients. The anticancer effects of IM are related to inhibition of COX‐2 as well as COX‐independent targets. We now report the synthesis and activity of novel IM‐sila‐ amide derivatives where strategic silicon addition results in COX‐2 selective IM derivatives that demonstrate activity in mouse models of human cancers and are devoid of the COX‐1 associated toxicities. The sila‐IM compounds demonstrated improved inhibition of purified human COX‐2, IC50 0.2 µM and limited inhibition of COX‐1 up to 10 µM. Sila‐IM derivatives were also found to be potent inhibitors of NFκB transcription activating function at concentrations below 1.0 µM. A sila‐IM derivative Silexsyn was tested in various animal models of human cancer following oral administration. Significant activity was observed in models of non‐small cell lung cancer and pancreas cancer. Potent synergism was observed for Silexsyn in combination with EGFR inhibitors. A synthetic methodology incorporating a heteroatom in the amino‐functional silane has been developed and used to generate second‐generation sila‐IM derivatives that could have improved pharmacological properties. The introduction of silicon into an approved scaffold represents an efficient strategy for the rapid production of biologically relevant therapeutics for the treatment of cancer. Citation Information: Cancer Res 2009;69(23 Suppl):C50.
Connections with multiple congested gateways in packet-switched networks part 1: one-way traffic

In this paper we explore the bias in TCP/IP networks against connections with multiple congested gateways. We consider the interaction between the bias against connections with multiple congested gateways, the bias of the TCP window modification algorithm against connections with longer roundtrip times, and the bias of Drop Tail and Random Drop gateways against bursty traffic. Using simulations and a heuristic analysis, we show that in a network with the window modification algorithm in 4.3 tahoe BSD TCP and with Random Drop or Drop Tail gateways, a longer connection with multiple congested gateways can receive unacceptably low throughput. We show that in a network with no bias against connections with longer roundtrip times and with no bias against bursty traffic, a connection with multiple congested gateways can receive an acceptable level of throughput.We discuss the application of several current measures of fairness to networks with multiple congested gateways, and show that different measures of fairness have quite different implications. One view is that each connection should receive the same throughput in bytes/second, regardless of roundtrip times or numbers of congested gateways. Another view is that each connection should receive the same share of the network's scarce congested resources. In general, we believe that the fairness criteria for connections with multiple congested gateways requires further consideration.
Local electronic transport at grain boundaries in Nb-dopedSrTiO3

The local electrostatic properties and electronic transport at $\ensuremath{\Sigma}5$ grain boundaries in donor-doped $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ bicrystals are examined using a combination of scanning probe microscopy (SPM) techniques and impedance spectroscopy. A combination of scanning surface potential microscopy (SSPM) and scanning impedance microscopy is used to determine intrinsic current-voltage and capacitance-voltage characteristics of the interface, eliminating the bulk and contact contributions. Conductive atomic force microscopy is used to directly image the depletion barrier associated with the grain boundary. The sign of the grain boundary potential is unambiguously determined by SSPM once the mobile charge effect is taken into account. A combination of SPM and impedance spectroscopy allowed the effect of grain boundary on local static and frequency dependent transport properties to be established.
The Scientific Status of Projective Techniques

Although projective techniques continue to be widely used in clinical and forensic settings, their scientific status remains highly controversial. In this monograph, we review the current state of the literature concerning the psy- chometric properties (norms, reliability, validity, incremental validity, treatment utility) of three major projective instru- ments: Rorschach Inkblot Test, Thematic Apperception Test (TAT), and human figure drawings. We conclude that there is empirical support for the validity of a small number of indexes derived from the Rorschach and TAT. However, the substantial majority of Rorschach and TAT indexes are not empirically supported. The validity evidence for human figure drawings is even more limited. With a few exceptions, projective indexes have not consistently demonstrated incremental validity above and beyond other psychometric data. In addition, we summa- rize the results of a new meta-analysis intended to examine the capacity of these three instruments to detect child sexual abuse. Although some projective instruments were better than chance at detecting child sexual abuse, there were virtually no replicated findings across independent investigative teams. This meta-analysis also provides the first clear evidence of substantial file drawer effects in the projectives literature, as the effect sizes from published studies markedly exceeded those from unpublished studies. We conclude with recommendations regarding the (a) construction of projective techniques with adequate validity, (b) forensic and clinical use of projective techniques, and (c) education and training of future psycholo- gists regarding projective techniques.
The architecture of support: The activation of preexisting ties and formation of new ties for tailored support

This study examines differences in the resources, information, and support parents coping with pediatric cancer accessed from different types of network contacts. Using interviews with parents of childhood cancer patients (N = 80 parents), we examine (1) if parents rely on different types of network ties to access tailored information, resources or support; (2) differences in the nature or utility of information, resources, and support offered by different types of network contacts; and (3) the role of health-related professionals in brokering new network ties. Findings show that after a child's cancer diagnosis, parents received support from a broad portfolio of network members, which included preexisting network ties to friends and families as well as the formation of new ties to other cancer families and health-related professionals. Family, friends, and neighbors offered logistical support that aided balancing preexisting work and household responsibilities with new obligations. Parents formed new ties to other families coping with cancer for tailored health-related emotional and informational support. Health-related professionals served as network brokers, who fostered the development of new network ties and connected parents with supportive resources.
Optical time-frequency scaling for signal processing applications

Optical time-frequency processing requires a combination of high-speed, quadratic phase modulators and dispersive delay lines. The latter is typically achieved using optical fibers, but can be compactly implemented and tunable using dispersive filters. Time scaling, either dilation or compression, can be achieved with these building blocks. While basic time scaling followed by direct detection has been demonstrated, we focus on cascading time-scale operations for potential signal processing applications and implementations using integrated-optic platforms. For cascaded operations, both the phase and amplitude of the scaled output must be correct. Time scaling is studied analytically and by simulations. Practical implementation issues are addressed such as the time aperture limits imposed by using sinusoidal phase modulation to approximate the desired quadratic response. The chirp and dispersion relationships are given for "factor of one half" and "factor of two" time scaling. The evolution of the signal's time support at intermediate points in the time-scaling operation is shown to be a critical parameter for practical implementations. Two optical time-scaling architectures are studied, and one is clearly better in this respect. Furthermore, a special case arises for a Gaussian input pulse whereby the number of elements needed to realize the time scaling can reduced by a factor of two. Applications for cascaded time scaling operations are discussed, including optical wavelet processing and photonic-assisted analog-to-digital conversion. By using the time-scale operation in the optical domain to mimic the discrete-time downsampling operation, we show that physical scaling of the optical filters between subsequent decomposition levels is not required.
Determination of biotypes of Haemophilus influenzae and Haemophilus parainfluenzae a comparison of methods and a description of a new biotype (VIII) of H. parainfluenzae.

Abstract A total of 180 strains of Haemophilus influenzae and 119 strains of Haemophilus parainfluenzae were characterized with respect to biotype (i.e., production of indole, urease, and ornithine decarboxylase) using conventional biochemical methods and two commercially available biotyping systems: Trio-Tube Haemophilus system (Carr Microbiologicals) and the Rapid NH System (Inovative Diagnostic Systems). Concordance between the results of the Trio-Tube system and conventional biochemicals was achieved with 294 of the 299 test organisms (98.3%). With the Rapid NH System, concordance with the results of conventional biochemical tests was observed with 275 of the 299 tests strains (92.0%). One previously unrecognized biotype of H. parainfluenzae , designated biotype VIII, is described. Typical reactions of this biotype include indole production but no production of urease or ornithine decarboxylase.
A computer system for hurricane hazard assessment

Abstract Rapid economic development and population growth in coastal regions of the U.S. has resulted in an increase in vulnerability of population and property to the hurricane hazard. State and local emergency management officials need a detailed information base of potential loss estimates to prepare sound emergency preparedness plans. A computer system, known as the Vulnerability Assessment and Mapping System (VAMS), has been designed to estimate the extent and spatial distribution of potential casualties, and losses to housing and commercial-industrial facilities as a result of hurricane landfall. The VAMS system is flexible as users can choose to consider different types of hurricanes with varying surge and wind patterns and points of landfall for determining potential loss estimates within a given study area. The results of the analysis can be displayed in computer-generated grid map form or as summary statistics in tabular form. The VAMS system is then applied to coastal portions of the Houston-Galveston metropolitan area in the State of Texas. The VAMS system is part of a comprehensive hurricane impact study for the Texas Governor's Division of Emergency Management.
The Promise of Paradise: Recreational and Retirement Communities in the United States since 1950

Since mid-century the mass-merchandising of recreational and retirement communities has mushroomed into a multibillion-dollar industry. But not all such communities have proven successful. Air travellers above the Sunbelt states often see vast tracts of land on which isolated, jigsaw-like patterns of roads lead nowhere. And the tongue-in-cheek offer of "land in Florida" has become proverbial for a foolish investment. In the first geographic and environmental analysis of the recreational and retirement community industry, Hubert B. Stroud shows how and why certain communities had positive impacts on the surrounding region while others did not. Focusing on well-known developments in Arizona, New Mexico, Florida, Arkansas, and Tennessee, he finds that most developments were poorly planned, resulting in environmental damage, overtaxing of public services, and social and economic problems. Yet Stroud acknowledges that future development is inevitable, as recreational and retirement communities continue to lure urban America with the promise of paradise.
Predicting the suicide rate of children in America.

The time-series regressions for suicide rates by race and sex for those aged 5 to 14 years in the USA from 1933-1980 were predicted by scores on two factors which had high loadings for year and for the marriage rate. Language: en
The nature of inequality : Uncovering the modern in Leo Strauss's idealist ethics

Etude de l'anti-egalitarisme et de la conception de l'inegalite developee par L. Strauss dans le cadre paradoxal de sa defense antiliberale de la democratie liberale. Examinant les sources de sa critique de l'egalite dans sa phenomenologie idealiste, l'A. montre que l'elitisme de Strauss releve a la fois du positivisme weberien, de la phenomenologie heideggerienne et de la philosophie grecque, celle-ci reposant sur la figure du philosophe et le partage naturel entre nobles et vils. Sans faire retour a l'idealisme classique, Strauss decouvre la modernite et l'actualite de l'homme a partir de sa possibilite pratique, caracterisee par une tension entre les requetes naturelles pour l'egalite et l'inegalite
Purification and characterization of sulfatases from Haliotis rufescens: evidence for changes in synthesis and heterogeneity during development.

The digestive glands of many marine molluscs are rich sources of arylsufatase enzymes which may function in the catabolism of sulfated polysaccharides in the diets of herbivorous species. Arylsulfatases, partially purified from the hepatopancreas of the red abalone, Haliotis rufescens, were investigated with respect to heterogeneity, catalytic requirements, and timing of induction during development. Four hepatopancreatic enzymes were purified from adult animals using a combination of hydrophobic interaction and anion-exchange chromatography. Zymograms of the four partially-purified enzymes produced by electrophoresis under nondenaturing conditions revealed a fifth, relatively more basic isozyme. All four partially-purified enzymes appear to be monomeric, with molecular weights of approximately 43 000 Da each, as measured by gel filtration. The affinities for p-nitrocatechol sulfate, pH optima, and strengths of inhibition by anions displayed by these enzymes are similar to the values reported for other molluscan arylsulfatases. Three of the four enzymes have Km values between 0.8 and 2.0 mM for p-nitrocatechol sulfate; the remaining enzyme (A2) has a Km of 6.7 mM. All four enzymes have pH and temperature optima of 5.5 and 45°C, respectively. Three of the four enzymes have-t1/2(50°C) values of 3.5 min; the enzyme A4 has a t1/2 has a t1/2(50°C) of 8.5 min. A monoclonal antibody directed against form A1b does not cross react with any of the other hepatopancreatic arylsulfatases when assayed by Western blot, confirming the structural heterogeneity of the adult enzymes.
Chronic exposure to 17α-ethinylestradiol reduces behavioral consistency in male Siamese fighting fish

Both acute and chronic exposure to 17α-ethinylestradiol (EE2), one of the primary active ingredients of birth control pills, decreases courtship and aggression in males of aquatic species. However, how exposure affects behavioral consistency over time is not commonly addressed. To examine the effects of chronic EE2 exposure on behavioral consistency, adult male Siamese fighting fish, Betta splendens, received multiple trials with a dummy male and dummy female presented simultaneously both before and after chronic exposure to a nominal dose (10 ng/l) of EE2. The responses of exposed males were compared before and after exposure and against those of a group of unexposed, control males. Male-directed and female-directed behaviors were reduced after 28 days of EE2 exposure. More importantly, chronic EE2 exposure had dramatic effects on consistent individual differences in female-directed and male-directed behaviors. Repeatability values were markedly lower and level of response was less correlated in the EE2 group, suggesting that exposure disrupts both between-individual variation and behavioral consistency. These results cannot be explained by a temporal effect as they were not found in the control group of unexposed males. This study demonstrates that EE2 exposure may have effects beyond a reduction in overall response. It also demonstrates the importance of studying the effects of chemical exposure on multiple time scales as acute exposure to EE2 affects the consistency of only female-directed behaviors in this species whereas chronic exposure affects consistency of both female-directed and male-directed behavior. Finally, this study suggests that males in this species may differ in their sensitivity, an important area for future research.
The Mesoscale and Microscale Structure and Organization of Clouds and Precipitation in Midlatitude Cyclones. VIII: A Model for the “Seeder-Feeder” Process in Warm-Frontal Rainbands

Abstract Previous field studies have indicated that warm-frontal rainbands form when ice particles from a “seeder” cloud grow as they fall through a lower-level “feeder” cloud. In this paper we present results from a parameterized numerical model of the growth processes that can lead to the enhancement of precipitation in a “seeder-feeder” type situation. The model is applied to two types of warm-frontal rainbands. In the first (Type 1 situation) the vertical air motions are typical of those associated with slow, widespread lifting in the vicinity of warm fronts. In the second (Type 2 situation) the vertical air motions are stronger, and more characteristic of the mesoscale. The model simulations show that in the Type 1 situations the growth of the “seed” ice crystals within the feeder zone is due to vapor deposition. The feeder zone in this case is slightly sub-saturated with respect to water due to the presence of the seed crystals. In regions where the feeder zone is not “seeded” from aloft, snow cryst...
Temporal broadening of ultrashort space-time Gaussian pulses with applications in laser satellite communication

In this paper, analytic expressions for the temporal broadening of narrowband space-time Gaussian pulses propagating in weak optical turbulence are derived for both near and far fields. General results are presented for nominal parameter values characterizing laser communication through the atmosphere. Specific examples are calculated for both upper atmosphere UAV-UAV cross-links and uplink/downlink satellite communication paths. It is shown that for both the near and far fields, pulses on the order of 10 - 20 femtoseconds can broaden by more than 100% whereas pulses greater than 500 femtoseconds have negligible broadening.
Unusual complement-mediated hemolytic kinetics at low ionic strength.

The dilution of human serum in relatively low ionic strength buffer (μ = 0.070) caused the spontaneous activation of C1 and a limited activation of C4 and C3 in the fluid phase. The unusual degree of activation of the complement system in the fluid phase suggested that the optimal functions of complement-regulatory systems such as C1 inhibitor might be reduced. As a function of the time of preincubation (PI) of diluted serum at 37°C, under low ionic strength conditions, an unusual complement-mediated hemolytic kinetic pattern was observed upon adding sensitized erythrocytes (EA). For a 1:36 dilution of human serum, there was an initial progressive decrease in complement hemolytic activity (from 3 to 20 min PI, phase I), followed by an apparent functional reversal (increase) in hemolytic activity (20–50 min PI, phase II) and finally a gradual irreversible depletion of the hemolytic activity (after 50 min PI, phase III). This hemolytic pattern could only be adequately demonstrated using a kinetic assay which followed the course of lysis of EA in the presence of low dilutions of human serum as a complement source. Others might have missed this observation due to the use of end-point titration methods which required the use of relatively elevated serum dilutions at the time of EA addition. Mechanisms which governed the variations in hemolytic activity at low ionic strength were not clear. Speculatively, partial consumption of early complement components, generation of free C1q and generation of complement fragments might have accounted for the initial decrease in the hemolytic activity observed in phase I. The apparent functional reversal of hemolytic activity observed in phase II might have involved a critical depletion of C1 inhibitor which occurred secondary to C1 inhibitor binding to C1 (activated by low ionic strength effects) and to the C1 activated at the time of EA addition. Without sufficient regulation, a rapid unrestricted C1-mediated complement activation could have occurred, which resulted in a rapid deposition of complement on the EA. Finally, prolonged exposure of serum to low ionic strength effects appeared to induce a significant complement consumption, which caused a time-dependent irreversible depletion of complement hemolytic activity (phase III). Excess exogenous C1 inhibitor, when co-incubated with diluted serum at low ionic strength, reversed the time-dependent effects of low ionic strength and enhanced the subsequent specific complement-mediated hemolytic activity as compared to controls. Thus it is suggested that excess C1 inhibitor mediated the prevention of non-productive spontaneous C1 activation and activated C1-mediated complement consumption in the fluid phase during the PI at low ionic strength.
Ethical principles in the conduct of menopause research

The same ethical principles that apply to biomedical research in general also govern research on menopause. The principles of respect for persons, beneficence, and justice embody ethical concerns in the selection and recruitment of subjects, the process of obtaining informed consent from potential subjects, the assessment of risks and benefits, and the conduct of the research itself. An argument might be made that to conduct research on menopause in which some subjects fail to receive-hormone replacement therapy would be unethical. This argument contains a number of fallacies. The assumption that women are incapable of weighing the risks and benefits and deciding whether to participate in the research betrays a lack of respect for women's capacity for critical evaluation. The principle of beneficence supports carrying out research to enhance the scientific knowledge on which to base treatment recommendations. The principle of justice requires that long-overdue research be conducted on aspects of the aging process affecting more than 50% of the population.
Cautionary lessons from assessing dental mesowear observer variability and integrating paleoecological proxies of an extreme generalist Cormohipparion emsliei

Abstract Dental mesowear is an inexpensive and expedient method used to characterize the average diet of herbivorous mammals, capturing wear produced over several months in the lifetime of an animal by both attrition and abrasion. Most dental mesowear methods focus on qualitatively categorizing cusp shapes as sharp, round, or blunt with high or low relief, sometimes classifying teeth into numerical categories that integrate these variables (typically 0 to 6, from sharp/high relief to blunt/low relief). As dental mesowear requires an observer to make subjective judgments regarding tooth categories, we assess observer variability and integrate carbon isotope and dental mesowear data to clarify if mesowear similarly records average dietary information in an extreme generalist herbivore (i.e., Cormohipparion emsliei ). Stable carbon isotope samples of C. emsliei from the Bone Valley of Florida (~ 5 Ma) yield a δ 13 C range of 13.7‰, suggestive of highly generalized dietary behavior ranging from primarily browsing to grazing. While average mesowear values for this population are partially consistent with a mixed feeding diet, individual δ 13 C values lack significant relationships with all mesowear variables, excluding relief. Further, individuals consuming disparate diets (i.e., individuals with the lowest and highest carbon isotope values of − 12.9‰ and 0.8‰, respectively) yield similar dental mesowear values (4.20 and 3.75, respectively). Dental mesowear analyses conducted by experienced versus minimally trained individuals are not significantly different from one another, suggesting that mesowear methods can be easily taught; however, the incorporation of multiple observers can reduce variability. Caution should be exercised when interpreting the diets of individuals based on dental mesowear alone.
Role of Liquid vs Vapor Water in the Hydrothermal Degradation of SBA-15

The hydrothermal stability of mesoporous silica is critical for applications including catalytic processing of biofuels due to the presence of significant amounts of water. We have combined neutron diffraction intensity analysis with NLDFT analysis of nitrogen sorption isotherms to characterize the spatial distribution of the secondary pore network in SBA-15 following postcalcination hydrothermal treatment in both liquid and vapor phase water at temperatures from 115 to 155 °C under autogenous pressure. The results are consistent with a degradation mechanism in which silica dissolves from regions of small positive curvature, e.g., near the entrance to the secondary pores, and is redeposited deeper into the framework. Pore volumes decrease fastest for the micropores and more slowly for larger secondary mesopores. Under water treatment at 115 °C, the mesopore diameter increases and the intrawall void fraction decreases significantly. The behavior is similar for steam treatment but occurs more slowly. Differ...
Teaching Fractions: Strategies Used for Teaching Fractions to Middle Grades Students

Abstract Fractions are often difficult for students to fully comprehend. Teachers must find a variety of strategies to use in the classroom for teaching fractions. This study was conducted to identify effective strategies used by middle school teachers in order to find ways to improve fraction instruction. For four months, data were collected in 12 classrooms, using observation notes, interviews, and videotaping. Findings are discussed within a constructivist framework.
Unequal modification of the thermal survival responses of clonal human colon carcinoma cell lines by decreased pH.

SummaryWe have investigated the responses of two closely related human colon tumour lines (clone A and clone D) to hyperthermic cell killing in vitro under two conditions of environmental acidity (pH values 7·40 and 6·75). At pH 7·40, under prolonged exposure to 42·5°C, both lines exhibited biphasic response curves with thermotolerance appearing at about 4 h of continuous heating. It was found that the clone D human tumour line was more resistant to hyperthermic inactivation than the clone A line. At pH 6·75, both lines exhibited increased sensitivity to heating killing at 42·5°C, but it was found that the effect was unequally demonstrated by the two human tumour lines (i.e. decreased pH was not acting simply as a dose modifying agent). Specifically, clone A exhibited a much greater hyperthermic sensitivity in the thermotolerant region of survival (i.e. a heating time of 4 h or more) than did clone D. Clinically, this result would suggest that although potential pH sensitization of heterogeneous tumours t...
The Management of Ventricular Arrhythmias in Older Patients After CAST

Asymptomatic nonsustained ventricular tachycardia and complex ventricular arrhythmias in elderly persons without heart disease should not be treated with antiarrhythmic drugs. Nonsustained ventricular tachycardia and complex ventricular arrhythmias in elderly persons are associated with an increased incidence of coronary events, primary ventricular fibrillation and sudden cardiac death, especially if abnormal left ventricular ejection fraction, left ventricular hypertrophy or silent ischaemia are present. beta-Blockers should be used in the treatment of elderly patients with ventricular tachycardia or complex ventricular arrhythmias associated with ischaemic or nonischaemic heart disease if there are no contraindications to beta-blocker therapy. I would reserve the use of amiodarone in the treatment of ventricular tachycardia or complex ventricular arrhythmias to life-threatening ventricular tachyarrhythmias in elderly patients who cannot tolerate or who do not respond to beta-blockers. Angiotensin converting enzyme (ACE) inhibitors should be used in treating elderly patients with ventricular tachycardia or complex ventricular arrhythmias associated with congestive heart failure. In patients with ventricular tachycardia or complex ventricular arrhythmias associated with asymptomatic left ventricular systolic dysfunction, I would use beta-blockers plus ACE inhibitors. If elderly patients have life-threatening, recurrent ventricular tachycardia or ventricular fibrillation resistant to antiarrhythmic drugs, invasive intervention is indicated. Until the results of prospective, randomised, clinical trials evaluating the automatic implantable cardioverter-defibrillator are available, I recommend using the automatic implantable cardioverter-defibrillator in elderly patients who have medically refractory sustained ventricular tachycardia or ventricular fibrillation.