cssi/SciSciGPT-SciSciNet huggingface dataset:
An Analysis of Metabolic Changes in the Retina and Retinal Pigment Epithelium of Aging Mice.

Purpose The purpose of this study was to present our hypothesis that aging alters metabolic function in ocular tissues. We tested the hypothesis by measuring metabolism in aged murine tissues alongside retinal responses to light. Methods Scotopic and photopic electroretinogram (ERG) responses in young (3-6 months) and aged (23-26 months) C57Bl/6J mice were recorded. Metabolic flux in retina and eyecup explants was quantified using U-13C-glucose or U-13C-glutamine with gas chromatography-mass spectrometry (GC-MS), O2 consumption rate (OCR) in a perifusion apparatus, and quantifying adenosine triphosphatase (ATP) with a bioluminescence assay. Results Scotopic and photopic ERG responses were reduced in aged mice. Glucose metabolism, glutamine metabolism, OCR, and ATP pools in retinal explants were mostly unaffected in aged mice. In eyecups, glutamine usage in the Krebs Cycle decreased while glucose metabolism, OCR, and ATP pools remained stable. Conclusions Our examination of metabolism showed negligible impact of age on retina and an impairment of glutamine anaplerosis in eyecups. The metabolic stability of these tissues ex vivo suggests age-related metabolic alterations may not be intrinsic. Future experiments should focus on determining whether external factors including nutrient supply, oxygen availability, or structural changes influence ocular metabolism in vivo.
Various Characterizations of Modified Weibull and Log-Modified Weibull Distributions

Various characterizations of the well-known modifiedWeibull and log-modifiedWeibull distributions are presented. These characterizations are based on a simple relationship between two truncated moments; on the hazard function and on functions of the order statistics.
The influence of rifampicin resistant mutations on the biosynthesis of exopolysaccharides by strain Escherichia coli K-12 lon

The influence of RNA polymerase (rif) mutations on the yield of capsular exopolysaccharide--colanic acid (CA) of Escherichia coli K-12 lon strain was studied. Five colanic acid isogenic producing strains were created by transduction transfer of rif alleles possessing pleiotropic effects. The obtained isogenic strains differed by specific growth rate, size and mucoidness of colonies, the dependence of growth on the medium composition and cultivation temperature, as well as by the adsorption rate of virulent bacteriophage M59, specifically lysing E. coli cells producing CA. Direct correlation between the yield of exopolysaccharides, growth rate and adsorption of bacteriophage M59 was revealed. Among rif recombinants strain AH203, which synthesized twice as much CA compared with the parental strain in submerged cultivation was selected.
Sequences and Series of Functions

The fact that polynomial functions are so ubiquitous in both pure and applied analysis can be attributed to any number of reasons. They are continuous, infinitely differentiable, and defined on all of R.They are easy to evaluate and easy to manipulate, both from the points of view of algebra (adding, multiplying, factoring) and calculus (integrating, differentiating). It should be no surprise, then, that even in the earliest stages of the development of calculus, mathematicians experimented with the idea of extending the notion of polynomials to functions that are essentially polynomials of infinite degree. Such objects are called power series, and are formally denoted by $$\sum\limits_{n = 0}^\infty {{a_n}} {x^n} = {a_0} + {a_1}x + {a_2}{x^2} + {a_3}{x^4} + \ldots $$ .
Otolaryngology Needs in a Free Clinic Providing Indigent Care

Objectives/Hypothesis To determine the otolaryngology needs in a free clinic providing care to medically indigent patients, as perceived by the patients and health care providers. Study Design Cross-sectional survey. Methods A survey was administered to patients and health care providers of a free clinic from September 2014 through January 2015 in an urban, inner-city location. Results One hundred and thirty-seven patients (35.8% male, age 50.8 ± 13.0 years) completed the survey. Mean household income was $29,838 ± $10,425; 32.1% spoke English; 54.7% were employed; 10.2% had health insurance; and 37.2% had seen a primary care provider outside of the free clinic. The top three otolaryngology symptoms among patients were sleep apnea/snoring (39.4%), heartburn/reflux (30.7%), and dizziness (29.9%). Eleven health care providers (45% male, age 50.5 ± 15.3 years, 63.6% physician, 36% nurse) completed the survey. Providers perceived the following otolaryngology complaints as the most prevalent, in descending order: cough, nasal congestion, reflux/heartburn, sore throat, and ear infection/otalgia. Providers felt that sleep apnea and hearing loss were the less common otolaryngology complaints, whereas surveyed patients indicated these symptoms with high frequency. The most requested diagnostic tool among patients and providers was chest X-rays. Conclusion There are unmet otolaryngology needs in a free clinic. Medically indigent patients have significant barriers to accessing health care. Patient and provider perceptions of top otolaryngology complaints differed, but both identified access to chest X-rays as a major unmet need. Knowledge of patient perceptions may help providers elicit the breadth of otolaryngology complaints. Level of Evidence 4. Laryngoscope, 2015
Leading Indicators of Inflation for Brazil

The goal of this project is to construct leading indicators that anticipate inflation cycle turning points on a real time monitoring basis. As a first step, turning points of the IPCA inflation are determined using a periodic stochastic Markov switching model. These turning points are the event timing that the leading indicators should anticipate. A dynamic factor model is then used to extract common cyclical movements in a set of variables that display predictive content for inflation. The leading indicators are designed to serve as practical tools to assist real-time monitoring of monetary policy on a month-to-month basis. Thus, the indicators are built and ranked according to their out-of-sample forecasting performance. The leading indicators are found to be an informative tool for signaling future phases of the inflation cycle out-of-sample, even in real time when only preliminary and unrevised data are available.
OCCUPANT INJURY ASSESSMENT CRITERIA

This paper is a brief review of the complex subject of human injury mechanisms and impact tolerance. Authomotive accident-related injury patterns are briefly described and the status of knowledge in the biomechanics of trauman of the head, neck, chest, abdomen and extremites is discussed. /Author/
Intrinsic or Extrinsic? Using Videogames to Motivate Stroke Survivors: A Systematic Review.

Abstract Objective: The main objective of this study was to explore, via a systematic review of available literature, the effectiveness of videogame-based rehabilitation interventions on the motivation and health outcomes of stroke patients. Materials and Methods: Using a systematic literature review of 18 articles, we sought to address three key research questions: (1) Do videogames improve function or health outcomes among stroke survivors? (2) Do videogames increase stroke patients' motivation to engage in rehabilitation exercise and activities? (3) Which motivational techniques, principles, and theoretical frameworks have been applied in the reviewed studies? A key word search was conducted, and articles were coded for inclusion of motivational theories or principles, intervention effectiveness, and participants' motivation to perform tasks. Three motivational frameworks and principles were used (self-determination theory [SDT], flow theory, and operant conditioning) to investigate intrinsic and extri...
Chloroquine modulation of specific metabolizing enzymes activities: investigation with selective five drug cocktail

Aims The aim of this study was to investigate whether chloroquine can inhibit drug metabolism in humans, if such inhibition is general or selective for certain enzymes and evaluate the potential for and clinical significance of any drug-drug interactions when chloroquine is co-administered with other drugs. Methods The study was conducted in fourteen normal non-smoking healthy male volunteers using a cocktail of five drugs consisting of caffeine, mephenytoin, debrisoquine, chlorzoxazone and dapsone to assess activities of cytochromes P450 (CYP) 1A2, 2C19, 2D6, 2E1 and 3A4 respectively. Dapsone was also used to assess N-acetyltransferase activity. The activities were assessed at baseline, after one and seven daily doses (250 mg daily) of chloroquine and 7 and 14 days after stopping chloroquine dosing. Results Chloroquine caused a progressive and significant decrease in CYP2D6 activity as measured by debrisoquine metabolism from first to seventh dose and the activity returned to baseline gradually over 14 days after stopping administration. There was no effect on the metabolism of any of the other probe drugs. Conclusions Chloroquine has been shown to be capable of inhibiting the activity of CYP2D6 in vivo in humans. This effect is selective as activities of other enzymes investigated were not affected. The effect was modest but suggests a potential for drug-drug interactions when co-administered with other drugs that are substrates for this enzyme. The clinical significance of such an interaction will depend on the therapeutic index of any drug involved.
Lead toxicity masquerading as sickle cell crisis

We recently saw a 12-year-old black boy with known sickle cell disease who had been seen many times for abdominal pain thought to be secondary to a vasoocclusive crisis. The patient eventually was admitted, after a seizure and the onset of obtundation. The etiology of his acute encephalopathy remained unclear until bone films of his knees fortuitously revealed "lead lines." The patient was treated and did well subsequently. This case emphasizes the importance of considering other diagnoses when a sickle cell patient presents with a crisis.
Accumulation of an iodophilic polysaccharide during growth of Acetivibrio cellulolyticus on cellobiose

Maximum growth of Acetivibrio cellulolyticus in 1% cellobiose (w/v, added as filter sterilized solution) medium was observed after about 24h of incubation at 35°C. The metabolic end products of growth were H2, CO2, acetic acid, ethanol and glucose. Growth was adversely affected if cellobiose was autoclaved with the rest of the media ingredients. In the presence of an excess of cellobiose, the cells accumulated large quantities of an iodophilic polysaccharide (IPS). The maximum IPS accumulation (about 37% of the cell dry weight) was observed after about 12h growth under nitrogen-limiting conditions. Starvation of these cells anaerobically, in a pH 7.0 phosphate buffer for 10 h at 35°C, resulted in about 50% drop in the IPS. The results also indicated that A. cellulolyticus accumulated this iodophilic polysaccharide during growth on cellobiose but not during cultivation on cellulose.
Symposium on reproduction of arthropods of medical and veterinary importance. IV. Reproduction in ticks (Ixodoidea).

Reproduction in ticks is discussed under the following: gametogenesis, meeting of the sexes, copulation, spermatophores, sperm relocation, syngamy, sperm longevity, and oviposition. The relationships among gametogenesis, copulation, oviposition and feeding are emphasized. Speculative suggestions as well as published and unpublished data are provided.
Expression of P-450 aromatase, estrogen receptor α and β, and α-inhibin in the fetal baboon testis after estrogen suppression during the second half of gestation

Expression of the molecules that modulate the synthesis and action of estrogen in, or reflect function of, Sertoli cells was determined in the fetal testis of baboons in which estrogen levels were suppressed in the second half of gestation to determine whether this may account for the previously reported alteration in fetal testis germ cell development. P-450 aromatase, estrogen receptor (ER) β, and α-inhibin protein assessed by immunocytochemistry was abundantly expressed in Sertoli cells of the fetal baboon testis, but unaltered in baboons in which estrogen levels were suppressed by letrozole administration. Moreover, P-450 aromatase and ERα and β mRNA levels, assessed by real-time RT-PCR, were similar in germ/Sertoli cells and interstitial cells isolated from the fetal testis of untreated and letrozole-treated baboons. These results indicate that expression of the proteins that modulate the formation and action of estrogen in, and function of, Sertoli cells is not responsible for the changes in germ cell development in the fetal testis of estrogen-deprived baboons.
Pathway for Degradation of Peptides Generated by Proteasomes A KEY ROLE FOR THIMET OLIGOPEPTIDASE AND OTHER METALLOPEPTIDASES

The degradation of cellular proteins by proteasomes generates peptides 2-24 residues long, which are hydrolyzed rapidly to amino acids. To define the final steps in this pathway and the responsible peptidases, we fractionated by size the peptides generated by proteasomes from beta-[14C]casein and studied in HeLa cell extracts the degradation of the 9-17 residue fraction and also of synthetic deca- and dodecapeptide libraries, because peptides of this size serve as precursors to MHC class I antigenic peptides. Their hydrolysis was followed by measuring the generation of smaller peptides or of new amino groups using fluorescamine. The 14C-labeled peptides released by 20 S proteasomes could not be degraded further by proteasomes. However, their degradation in the extracts and that of the peptide libraries was completely blocked by o-phenanthroline and thus required metallopeptidases. One such endopeptidase, thimet oligopeptidase (TOP), which was recently shown to degrade many antigenic precursors in the cytosol, was found to play a major role in degrading proteasome products. Inhibition or immunodepletion of TOP decreased their degradation and that of the peptide libraries by 30-50%. Pure TOP failed to degrade proteasome products 18-24 residues long but degraded the 9-17 residue fraction to peptides of 6-9 residues. When aminopeptidases in the cell extract were inhibited with bestatin, the 9-17 residue proteasome products were also converted to peptides of 6-9 residues, instead of smaller products. Accordingly, the cytosolic aminopeptidase, leucine aminopeptidase, could not degrade the 9-17 residue fraction but hydrolyzed the peptides generated by TOP to smaller products, recapitulating the process in cell extracts. Inactivation of both TOP and aminopeptidases blocked the degradation of proteasome products and peptide libraries nearly completely. Thus, degradation of most 9-17 residue proteasome products is initiated by endoproteolytic cleavages, primarily by TOP, and the resulting 6-9 residue fragments are further digested to amino acids by aminopeptidases.
Graphene Adsorbed on Corundum Surface: Clean Interface and Band Gap Opening

Using advanced first-principles calculations, we have studied the structural and electronic properties of graphene/α-Al2O3 interfaces and show that α -Al2O3 is an ideal gate dielectric material for graphene transistors. Clean interface exists between graphene and Al-terminated (or hydroxylated) Al2O3 and the valence band offsets for these systems are large enough to create injection barrier. Remarkably, a band gap of ~180 meV can be induced in graphene layer adsorbed on Al-terminated surface, which is significantly larger than graphene on other popular substrates.
A Constructive Interpretation of the Full Set Theory

The interpretation of the ZF set theory reported in this paper is, actually, part of a wider effort, namely, a new approach to the foundation of mathematics, which is referred to as The Cybernetic Foundation. A detailed exposition of the Cybernetic Foundation will be published elsewhere. Our approach leads to a full acceptance of the formalism of the classical set theory, but interprets it using only the idea of potential, but not actual (completed) infinity, and dealing only with finite objects that can actually be constructed. Thus we have a finitist proof of the consistency of ZF. This becomes possible because we set forth a metatheory of mathematics which goes beyond the classical logic and set theory and, of course, cannot be formalized in ZF, yet yields proofs which are as convincing—at least, from the author's viewpoint—as any mathematical proof can be.Our metatheory is based on the following two ideas. Firstly, we define the semantics of the mathematical language using the cybernetical concept of knowledge. According to this concept, to say that a cybernetic system (a human being, in particular) has some knowledge is to say that it has some models of reality. In the Cybernetic Foundation we consider mathematics as the art of constructing linguistic models of reality.
Caroli's syndrome in a 1-year-old child.

Figure A. Cross-section of a liver showing tubular dilation of the segmental bile ducts. This liver is from a 1-yearold girl who underwent liver transplantation for Caroli’s syndrome, a condition characterized by dilated multifocal segmental bile ducts. (Gross photograph.) Figure B. Intrahepatic choledochal cysts in Caroli’s syndrome. Irregularly distributed within the liver are ectatic bile ducts forming cysts of various sizes, separated by portions of bile ducts that are normal or regularly dilated. The main characteristic of these cysts is their communication with the biliary tract, shown by the presence of inspissated bile (pools of golden-yellow pigment) within the ectatic ducts. (Low-power microscopic photograph.) Figure C. Secondary biliary cirrhosis in Caroli’s syndrome. Irregular to round regenerative nodules arranged in a geographic or garland pattern are separated by fibrous septa (blue-stained collagen) showing periseptal lamellar fibrosis with a thin rim of edema around the periphery of the nodules. (Low-power microscopic photograph, trichrome stain.) Figure D. Dilated bile duct containing inspissated bile and a thickened wall caused by marked chronic inflammation. Approximately half the cases of Caroli’s syndrome are associated with congenital hepatic fibrosis or polycystic liver disease. No von Meyenburg complexes, areas of congenital hepatic fibrosis, or other features of congenital duct or plate abnormalities seen in the spectrum of fibropolycystic liver disease are identified in this patient. (High-power microscopic photograph.)
Exercise-induced interstitial pulmonary edema at sea-level in young and old healthy humans

We asked whether aged adults are more susceptible to exercise-induced pulmonary edema relative to younger individuals. Lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (Dm) and pulmonary-capillary blood volume (Vc) were measured before and after exhaustive discontinuous incremental exercise in 10 young (YNG; 27±3 years) and 10 old (OLD; 69±5 years) males. In YNG subjects, Dm increased (11±7%, P=0.031), Vc decreased (-10±9%, P=0.01) and DLCO was unchanged (30.5±4.1 vs. 29.7±2.9mL/min/mmHg, P=0.44) pre- to post-exercise. In OLD subjects, DLCO and Dm increased (11±14%, P=0.042; 16±14%, P=0.025) but Vc was unchanged (58±23 vs. 56±23mL, P=0.570) pre- to post-exercise. Group-mean Dm/Vc was greater after vs. before exercise in the YNG and OLD subjects. However, Dm/Vc was lower post-exercise in 2 of the 10 YNG (-7±4%) and 2 of the 10 OLD subjects (-10±5%). These data suggest that exercise decreases interstitial lung fluid in most YNG and OLD subjects, with a small number exhibiting evidence for exercise-induced pulmonary edema.
Testing the role of contaminants in depressing avian numbers

Los contaminantes ambientales son ubicuos y a menudo los principales sospechosos en los casos de disminucion en las poblaciones de fauna silvestre. ?Como probamos las hipotesis sobre las relaciones causa - efecto entre los contaminantes y la salud de la fauna silvestre? Presentamos tres estudios de caso en que se usaron diferentes aproximaciones para someter a prueba las hipotesis sobre los efectos de los contaminantes sobre la fauna silvestre. Los casos involucran los posibles impactos de (1) el bifenilos policlorados en el aguila calva (Haliaeetus leucocephalus) en el Lago Superior; (2) las dioxinas sobre el aguila pescadora (Pandion halieatus); y (3) el mercurio de metilo en colimbo grande (Gavia immer). Las limitaciones legales, logisticas y financieras, determinaron diferentes aproximaciones en estos estudios, pero se destaca que la fuerza relativa de las aproximaciones experimentales y mecanicistas es superior a la de un acercamiento correlacional. Se demuestra que, en todas las especies la correlacion simple entre un solo contaminante y su actuacion esta enmascarada por su covariacion con otros tipos de contaminantes y/o los factores ecologicos naturales como disponibilidad de comida y depredacion
Loop-Mediated Isothermal Amplification and Polymerase Chain Reaction Methods for Specific and Rapid Detection of Rhodococcus fascians.

Serdani, M., Curtis, M., Miller, M. L., Kraus, J., and Putnam, M. L. 2013. Loop-mediated isothermal amplification and polymerase chain reaction methods for specific and rapid detection of Rhodococcus fascians. Plant Dis. 97:517-529. Rhodococcus fascians is a phytopathogenic actinobacterium which causes leafy galls and other plant distortions that result in economically significant losses to nurseries producing ornamental plants. Traditional assays for detection and identification are time-consuming and laborious. We developed a rapid polymerase chain reaction (PCR) diagnostic assay based on two primer pairs, p450 and fas, which target the fasA and fasD genes, respectively, that are essential for pathogenicity. We also developed a faster, more convenient, loop-mediated isothermal amplification (LAMP) assay targeting the fasR gene, which regulates expression of virulence genes. Both assays were evaluated for sensitivity and specificity in vitro and in planta. The p450 and fas primers amplified DNA only from pure cultures of pathogenic reference isolates of R. fascians. Nonpathogenic isolates and 51 other plantassociated bacteria were not amplified. The PCR primers correctly detected pathogenic R. fascians from 73 of 75 (97%) bacterial strains isolated from naturally infected plants. The PCR assay correctly discriminated between pathogenic R. fascians and other bacteria in 132 of 139 (95%) naturally infected plants, and in 34 of 34 (100%) artificially inoculated plants. The fas primers were slightly more accurate than the p450 primers. The LAMP assay accurately detected pathogenic R. fascians in 26 of 28 (93%) naturally infected plants and did not react with 23 asymptomatic plants. The LAMP primers also amplified product for DNA extracts of 40 of 41 bacterial strains isolated from plants with leafy galls. The detection limit of both the PCR and LAMP assays was approximately 103 CFU/30-µl reaction. These new tools allow fast, reliable, and accurate detection of R. fascians in vitro and in planta. The LAMP assay in particular is a significant advancement in rapid R. fascians diagnostics, and enables those with limited laboratory facilities to confirm the presence of this pathogen in infected plants.
Egg load influences search intensity, host selectivity, and clutch size in Battus philenor butterflies

Numerous studies have documented the influence of environmental factors such as host plant species and host quality on the oviposition behavior of female insects. This paper shows that an internal physiological factor, the number of mature eggs a female carries (egg load), correlates with host selectivity and clutch size in unmanipulated natural populations of the pipevine swallowtail butterfly, Battus philenor.In addition, search intensity and host selectivity differed among females whose egg loads were manipulated experimentally before they were released and followed in the field. Females with many eggs searched more intensely for hosts and were less selective when they encountered them.
Injury from the decompression component of an air-blast wave.

PREVIOUS experiments have shown that about 80 per cent mortality is to be expected when 60-day old mice are explosively decompressed, in a matter of 30 m.sec., from a pressure of 80 lb. per sq. in. above atmospheric. Since the positive phase of an air blast wave is characterized by a shock front followed by a rapid drop in pressure comparable to explosive decompression, it was thought of interest to investigate the lethal effect of this component of the blast wave. Accordingly, mice were subjected to 80 lb. per sq. in. over-pressure for varying durations of time and then explosively decompressed. No lethal effect was observed until the mice had been under pressure for times longer than 100 m.sec. At 1 second the mortality had only risen to about 12 per cent, as compared with the control data on 80 per cent mortality which was obtained when the mice were under pressure for a matter of 1 min. It is therefore concluded that the explosive decompression component of the blast wave has no lethal effect per se. Details of this work will be reported later.
Accurate H3 dynamics on an accurate H3 potential surface

Converged quantum close coupling calculations for the hydrogen exchange reaction on the chemically accurate potential surface of Siegbahn and Liu, using the fit of Truhlar and Horowitz, are reported. Comparisons are made with the Porter–Karplus potential energy surface.
Staining with Phloxine

A double stain with Magdala red and anilin blue has sometimes given very satisfactory results; but, just as often, has been entirely worthless. The reason for the discrepancy seems to be that stains sold under the name of Magdala red are of various composition, some of them containing no Magdala red at all. The standardized stain phloxine seems to be identical with successful lots of Magdala red and results are rather uniformly successful. Detailed directions for staining with phloxine and anilin blue will be published in a forthcoming number of Stain Technology.
The inertial effect on the natural convection flow within a fluid-saturated porous medium

Abstract The general momentum equation for fluid flow within a porous medium is supposedly valid for any fluid-porous medium configuration. One of the main concerns of using the general equations refers to the inclusion of both inertia terms, namely, the convective inertia term and the Forchheimer term. In this study, we go beyond the important discussion about the correctness of including both terms in the general momentum equations by focusing upon the effect of the convective inertia term on the heat transfer results. The fluid-porous medium system considered here is a cavity bounded by solid surfaces with vertical walls maintained at constant but different temperatures. The natural convection problem is solved numerically, and the results are compared with a general theory developed by using the method of scale analysis. It is demonstrated that the convective inertia term effect upon the heat transfer results is minor for 0.01 ≤ Pr ≤ 1, 10 ≤ RaD ≤ 104, 10−8 ≤ Da ≤ 10−2, and porosities 0.4 and 0.8. It is also shown that, contrary to the general belief, the convective inertial effect upon the heat transfer within the cavity is minimized when the Prandtl number is reduced.
The Importance of Love as a Basis of Marriage: Revisiting Kephart (1967)

This study extended prior research on attitudes about the importance of love as a basis for marriage. With data from a sample of 4,245 college students, obtained over a 16-year period, we found that both men and women, but women to a slightly greater degree than men, rated love as important for entering marriage. Over the 16-year period of the study, the importance of love as a prerequisite for marriage decreased slightly for men. Other individual difference variables (beyond gender) that were found to be associated positively with viewing love as an important basis for marriage included being White (vs. Black), high self-esteem, restrictedness in sociosexuality (true for women only), and a secure attachment style. Participants were more undecided or ambivalent about whether love is necessary to maintain a marriage. The importance of love for maintaining marriage was rated slightly higher by women (than by men), less religious participants, those whose parents had divorced, and those who were unrestricted...
Synaptonemal complex complement of man in spreads of spermatocytes, with details of the sex chromosome pair

Human pachytene chromosome pairs have been characterized electron microscopically in spread preparations on the basis of synaptonemal complex length, kinetochore position and attached nucleoli when present. The X and Y chromosomes can be followed by their filamentous axial cores from partial synapsis, through precocious disjuction and end-to-end attachment, to differentiation of a network in the sex chromosome pair.
Absolute measurements of optical oscillator strengths of noble-gas resonance lines

We have remeasured the optical oscillator strengths of eight noble-gas resonance lines in the vacuum-ultraviolet region. The measurements use a 900-eV collimated electron beam to excite the atoms, and the transmission of the emitted radiation is measured as a function of the gas density. In the method of self-absorption used here, the measured oscillator strengths are proportional to the distance between the electron beam and the fixed aperture of the spectrometer-detector system. We investigated and eliminated a possible systematic effect in the determination of the absorption length due to deflections of the electron beam. These measurements are performed at higher energies than our previous experiments at 100 eV in order to keep the electron-beam path better defined and aligned with the electron-gun apertures. The measured absolute oscillator strengths are He I (58.4 nm), 0.2700\ifmmode\pm\else\textpm\fi{}0.0076 (2.8%); He I (53.7 nm), 0.0737\ifmmode\pm\else\textpm\fi{}0.0023 (3.1%); Ne I (74.4 nm), 0.010 95\ifmmode\pm\else\textpm\fi{}0.000 32 (2.9%); Ne I (73.6 nm), 0.1432\ifmmode\pm\else\textpm\fi{}0.0038 (2.6%); Ar I (106.7 nm), 0.0580\ifmmode\pm\else\textpm\fi{}0.0017 (2.9%); Ar I (104.8 nm), 0.2214\ifmmode\pm\else\textpm\fi{}0.0068 (3.1%); Kr I (123.6 nm), 0.1775\ifmmode\pm\else\textpm\fi{}0.0050 (2.8%); and Kr I (116.5 nm), 0.1416\ifmmode\pm\else\textpm\fi{}0.0041 (2.9%).
Hydrology and aquatic habitat characteristics of a riverine swamp: II. Hydrology and the occurrence of chronic hypoxia

We examined the temporal and spatial occurrence of hypoxia (dissolved oxygen concentrations<2.0 mg L−1) in a 254-km2 portion of the Atchafalaya Basin floodway for 25 months (September 1993–September 1995) and analysed its relationship to local and basin-wide hydrology. Hypoxia occurred in channels with low turbulence whenever a flood pulse traveled through the system and mean water temperature exceeded 15°C. The number of hypoxic stations was linearly related to both river stage and air temperature. Tidal fluxes and weather-related variables (i.e. wind speed and direction, accumulated rainfall) did not significantly influence when, or the number of stations at which, hypoxia occurred. Additionally, hypoxia occurred at different times within different regions of the swamp. Total organic-carbon concentrations were relatively low throughout the study area when hypoxia occurred, and (although we acknowledge limitations of our data) we suspect that regional differences in organic-matter concentrations (leading to differences in metabolic consumption of dissolved oxygen) had little effect on when or where hypoxia occurred. Instead, we believe that regional paths of water flow affected how water was transported from turbulent-flowing channels into and through channels containing low- or non-turbulent flows. Water movement out of channels with low turbulence was impeded in each region during different stages of the flood pulse, and this event coincided with the most extensive occurrence of hypoxia within each region. The magnitude and duration of the flood pulse as well as the interior paths of water flow significantly influenced the severity and duration of hypoxia in this riverine swamp. Copyright © 1999 John Wiley & Sons, Ltd.
Fluorophores at the N Terminus of Nascent Chloramphenicol Acetyltransferase Peptides Affect Translation and Movement through the Ribosome

Structurally different fluorescent probes were covalently attached to methionyl-tRNA(f) and tested for their incorporation into nascent peptides and full-length protein using an Escherichia coli cell-free coupled transcription/translation system. Bovine rhodanese and bacterial chloramphenicol acetyltransferase (CAT) were synthesized using derivatives of cascade yellow, eosin, pyrene, or coumarin attached to [(35)S]Met-tRNA(f). All of the probes tested were incorporated into polypeptides, although less efficiently when compared with formyl-methionine. Eosin, the largest of the fluorophores used with estimated dimensions of 20 x 11 A, caused the largest reduction in product formed. The rate of initiation was reduced with the fluorophore-Met-tRNA(f) compared with fMet-tRNA(f) with pyrene having the least and eosin the biggest effect. Analysis of the nascent polypeptides showed that the modifications at the N terminus affected the rate at which nascent CAT peptides were elongated causing accumulation of peptides of about 4 kDa, possibly by steric hindrance inside the tunnel within the 50 S ribosomal subunit. Fluorescence measurements indicate that the probe at the N terminus of nascent pyrene-CAT peptides is in a relatively hydrophilic environment. This finding is in agreement with recent data showing cross-linking of the N terminus of nascent peptides to nucleotides of the 23 S ribosomal RNA.
Gene sequence, overproduction, purification and determination of the wild-type level of the Escherichia coli flagellar switch protein FliG

The flagellar motor switch in Escherichia coli and Salmonella typhimurium controls swimming behavior by regulating the direction of flagellar rotation. The switch is a complex apparatus composed of at least three proteins--FliG, FliM and FliN. During chemotactic behavior, the switch responds to signals transduced by the chemotaxis sensory signaling system. CheY, the chemotaxis response regulator, is thought to act directly on the switch to induce tumbles in the swimming pattern, but physical interaction of CheY and switch proteins has not been shown. We have undertaken this work to develop the molecular tools to investigate CheY binding to switch proteins, as well as to understand more about the structure and function of the switch. We present here the sequences of the fliG gene and its protein product, the engineering and amplification of fliG by the polymerase chain reaction (PCR) and its subcloning, and the overproduction, purification and determination of the wild-type (wt) level of the FliG protein. The sequence data revealed a 91.8% amino acid (aa) identity between E. coli and S. typhimurium FliG. Engineering and amplifying fliG by PCR allowed convenient cloning into an efficient expression vector. FliG was successfully overproduced and purified to > 98% purity. Polyclonal antibodies (Ab) were generated against purified FliG and used in quantitative Western blots to determine that the wt expression level of fliG results in about 3700 FliG copies per cell. Purified FliG and anti-FliG Ab will be useful for direct biochemical analyses of CheY-switch protein interaction.
Formation of an activated N-nitroso compound in nitrite-treated fava beans (Vicia faba)

Fava beans are prominent in the diet of the Colombian population at high gastric cancer risk. Upon nitrite treatment under simulated gastric conditions, a potent mutagen was formed as detected by a forward mutation assay using Salmonella typhimurium TM677 without microsomal activation. The promutagen was partially purified by preparative t.l.c. and normal phase h.p.l.c. of the acetone-soluble portion of a dried aqueous extract. The nitrosated promutagen fully accounted for the mutagenicity observed with whole fava beans. One gram of fresh fava beans yielded approximately 0.35 nmol of mutagen. Mutagenicity data indicated that this mutagen was more potent than N-methyl-N'-nitro-N-nitrosoguanidine. The characteristics of the mutagen were typical of an activated N-nitroso compound, that is a compound in which the N-nitroso moiety is attached to an activating group, such as a carbonyl group. Irradiation of the mutagen yielded a Griess positive reaction. By reverse-phase h.p.l.c. photohydrolysis, a single peak could be ascribed to the mutagen. Its stability varied as a function of pH, being most unstable under alkaline conditions. Cysteine and phosphate concentration had no effect on its rate of decomposition, thereby strongly suggesting that the mutagen is an N-nitrosourea. The results obtained in this study support the hypothesis of carcinogenesis via the intragastric production of activated N-nitroso compounds.
MODTRAN6: a major upgrade of the MODTRAN radiative transfer code

The MODTRAN6 radiative transfer (RT) code is a major advancement over earlier versions of the MODTRAN atmospheric transmittance and radiance model. This version of the code incorporates modern software ar- chitecture including an application programming interface, enhanced physics features including a line-by-line algorithm, a supplementary physics toolkit, and new documentation. The application programming interface has been developed for ease of integration into user applications. The MODTRAN code has been restructured towards a modular, object-oriented architecture to simplify upgrades as well as facilitate integration with other developers' codes. MODTRAN now includes a line-by-line algorithm for high resolution RT calculations as well as coupling to optical scattering codes for easy implementation of custom aerosols and clouds.
Influence of subsurface biosphere on geochemical fluxes from diffuse hydrothermal fluids

Hydrothermal vents along mid-ocean systems host unique, highly productive biological communities, based on microbial chemoautotrophy, that thrive on the sulphur, metals, nitrogen and carbon emitted from the vents into the deep ocean. Geochemical studies of vents have centred on analyses of high-temperature, focused hydrothermal vents, which exhibit very high flow rates and are generally considered too hot for microbial life. Geochemical fluxes and metabolic activity associated with habitable, lower temperature diffuse fluids remain poorly constrained. As a result, little is known about the extent to which microbial communities, particularly in the subsurface, influence geochemical flux from more diffuse flows. Here, we estimate the net flux of methane, carbon dioxide and hydrogen from diffuse and focused hydrothermal vents along the Juan de Fuca ridge, using an in situ mass spectrometer and flowmeter. We show that geochemical flux from diffuse vents can equal or exceed that emanating from hot, focused vents. Notably, hydrogen concentrations in fluids emerging from diffuse vents are 50% to 80% lower than predicted. We attribute the loss of hydrogen in diffuse vent fluids to microbial consumption in the subsurface, and suggest that subsurface microbial communities can significantly influence hydrothermal geochemical fluxes to the deep ocean.
Late Pleistocene eolian features in southeastern Maryland and Chesapeake Bay region indicate strong WNW–NW winds accompanied growth of the Laurentide Ice Sheet

Abstract Inactive parabolic dunes are present in southeastern Maryland, USA, along the east bank of the Potomac River. More elongate and finer-grained eolian deposits and paha-like ridges characterize the Potomac River–Patuxent River upland and the west side of Chesapeake Bay. These ridges are streamlined erosional features, veneered with eolian sediment and interspersed with dunes in the low-relief headwaters of Potomac- and Patuxent-river tributaries. Axis data for the dunes and ridges indicate formation by WNW–NW winds. Optically stimulated luminescence and radiocarbon age data suggest dune formation from ∼ 33–15 ka, agreeing with the 30–13 ka ages Denny, C.S., Owens, J.P., Sirkin, L., Rubin, M., 1979. The Parsonburg Sand in the central Delmarva Peninsula, Maryland and Delaware. U.S. Geol. Surv. Prof. Pap. 1067-B, 16 pp. suggested for eolian deposits east of Chesapeake Bay. Age range and paleowind direction(s) for eolian features in the Bay region approximate those for late Wisconsin loess in the North American midcontinent. Formation of midcontinent loess and Bay-region eolian features was coeval with rapid growth of the Laurentide Ice Sheet and strong cooling episodes (δ18O minima) evident in Greenland ice cores. Age and paleowind-direction coincidence, for eolian features in the midcontinent and Bay region, indicates strong mid-latitude WNW–NW winds for several hundred kilometers south of the Laurentide glacial terminus that were oblique to previously simulated anticyclonic winds for the last glacial maximum.
What Happened in the Rainier Grand's Lobby? A Question of Sources

One of the enduring narrative tensions that animates much of American environmental historiography is the conflict between those who argue for the preservation of natural spaces and those who call for their conservation-and use. Made to stand as champions of these two apparently irreconcilable ideological positions are John Muir, one of the founders and first president of the Sierra Club, and Gifford Pinchot, who helped establish the Forest Service of the United States Department of Agriculture (USDA) and served as its first chief. The older Muir initially befriended the younger Pinchot; they met in June 1893 in the New York City home of James and Mary Eno Pinchot, when Muir was fifty-five and Pinchot was thirty-one. Thereafter they maintained a lively correspondence, and when possible they hiked and camped amid some of the West's most spectacular landscapes. Their amiable relationship allegedly soured in the late 1890s due to sharpening differences in their perspectives on the human place in nature. These differences came to outweigh the benefits they had derived from their excursions into the wild. 1 No moment seems to have captured this rupture more vividly than an apparently heated exchange between the two men in the lobby of Seattle's Rainier Grand Hotel, sometime early in September 1897. Please note the qualifiers in the preceding sentence. Although many historians have recounted the incident in some detail and believe it signaled an irreparable breach in the men's personal relationship, and consequently in the two wings of the political movement with which they are so strongly identified, there is no incontrovertible evidence that it ever happened. I did not know that when I began work on a biography of Pinchot, in the pages of which-I must confess-I had expected to renarrate this tale because of its inherent drama and symbolic importance. It was only after I had read through the various secondary accounts that I noticed some small discrepancies that then forced me to sift through the relevant primary sources, research that could not confirm the substance of the story as it has been told.
The Role of Memory in Stabilizing Swarms

In this paper, we analyze and evaluate swarm interactions using varying amounts of kinetic memory, defined as the stored velocity states for n discrete time steps in the past. We show that kinetic memory can play a key role in the dynamics of biological and artificial aggregations. It is reasonable to suppose that individuals possess a memory of the immediate past and use this information to their advantage when swarming. Similarly, in wireless robotic applications, the storage of past movements requires nocommunication and can be used to stabilize aggregations. In fact, in wireless robotic applications, the communication rate between nearby individuals is more limited than in many biological applications, so the time step used to update an individual's velocity is greater. In this paper, we develop and analyze updating schemes for interacting individuals in a swarm. We show that we can stabilize and destabilize coherent translating structures using suitable adjustments to the updating scheme. Using this framework, we design an updating scheme to provide maximum stability for coherent structures that arise from a three-zone swarming model. Finally, we verify the effectiveness of our updating methodology using realistic QualNet simulations of a swarm of networked robots.
A model for the genetic control of differential adhesion in insect epidermis.

Abstract Adhesive relations among cells are believed to play a major role in determining patterns of serial homology, of intercalary regeneration, and of neuronal connectivity. Models for the genetic control of adhesion during development can provide a framework for further analysis of these phenomena. Investigators studying development of Drosophila have proposed that differentiation of segments and of imaginal discs is controlled by a set of bistable “selector genes”. In each region the settings of the selector genes form a binary “word” which determines the properties of cells in the region, including their adhesiveness. I have made an explicit proposal for the relation between binary words and adhesiveness, by assuming that active selector genes repress synthesis of “adhesor” macromolecules, which promote adhesion. This hypothesis correctly predicts the relative cohesiveness of cells in four pupal tissues of the moth Manduca . Works of cohesion and adhesion among the four cell types are deduced from published results of grafting experiments by modelling insect epidermis as a viscoelastic fluid. Further comparisons between deductions from the genetic and fluid models suggest that selector genes, or the adhesor molecules they regulate, interact within single cells in determining adhesiveness between cells. From a specific version of the genetic model I deduce that pairwise interactions between selector genes or adhesor molecules can determine many, though not all, of the relative works of adhesion between unlike cells in Manduca . The genetic and fluid models thus provide a set of working hypotheses for predicting patterns of intercellular adhesion in insect epidermis and for analyzing results of experiments designed to test such predictions.
Multicommodity Distribution System Design by Benders Decomposition

A commonly occurring problem in distribution system design is the optimal location of intermediate distribution facilities between plants and customers. A multicommodity capacitated single-period version of this problem is formulated as a mixed integer linear program. A solution technique based on Benders Decomposition is developed, implemented, and successfully applied to a real problem for a major food firm with 17 commodity classes, 14 plants, 45 possible distribution center sites, and 121 customer zones. An essentially optimal solution was found and proven with a surprisingly small number of Benders cuts. Some discussion is given concerning why this problem class appears to be so amenable to solution by Benders’ method, and also concerning what we feel to be the proper professional use of the present computational technique.
Multiparticle Monte Carlo moves: Algorithm for solids with free-energy determination

Abstract Multiparticle Monte Carlo moves can be conveniently implemented for the simulation of hard-core solids, and are shown to significantly reduce computer time. A method for the calculation of the free energy with fully vectorized sampling is also presented. We discuss how the algorithm can be generalized to treat systems with continuous interactions and, possibly, less translational order than crystals.
Principal component analysis delineates both subgroup- and patient-specific insights into acute inflammation in trauma patients

Results: Mortality was 14% (76 patients). Increases in pressures were associated with small but statistically significant decreases in HR complexity; associations between RR and HR complexity were not significant (Table 1). Decreased HR complexity remained a significant explanatory variable in logistic regression, after incorporating ventilator parameters (Table 2). Conclusions: 1. Pressure, but not rate, of mechanical ventilation may be important in interpreting integer HR complexity.