cssi/SciSciGPT-SciSciNet huggingface dataset:
Intracellular conversions of deoxyribonucleosides by Novikoff rat hepatoma cells and effects of hydroxyurea.

The incorporation of 3H-labeled deoxyadenosine and deoxyguanosine into nucleic acids by cultured Novikoff rat hepatoma cells is about 80% into RNA and 20% into DNA. The pathways of incorporation have been elucidated in studies with whole cells and cell-free extracts. Deoxyadenosine is very rapidly deaminated to deoxyinosine. Most of the deoxyinosine formed by whole cells is transported out of the cells and accumulates in the medium. A portion of the deoxyinosine, and deoxyguanosine are phosphorolyzed by purine nucleoside phosphorylase to hypoxanthine and guanine, respectively. The latter are subsequently converted by hypoxanthine-guanine phosphoribosyl transferase to IMP and GMP, respectively. Incorporation of the purine deoxyribonucleosides into DNA is mainly via this pathway and the subsequent reduction of ADP and GDP by ribonucleoside reductase, although a small proportion of the deoxyadenosine and deoxyguanosine taken up by the cells seems to be directly phosphorylated to dAMP and dGMP, respectively. Deoxyguanosine is incorporated only into guanine residues of RNA and DNA. Deoxyadenosine is also mainly incorporated into guanine residues of RNA and DNA, although the radioactivity of deoxyadenosine in the acid-soluble pool is almost exclusively associated with ATP. A similar labeling pattern is observed with labeled deoxyinosine, inosine or hypoxanthine. The pyrimidine deoxyribonucleosides, on the other hand, are specific precursors for their respective bases in DNA. Hydroxyurea inhibits the incorporation of all deoxyribonucleosides into DNA. Results from pulse-chase experiments indicate that the inhibition of DNA synthesis is prevented by the presence of high concentrations of deoxyadenosine plus deoxyguanosine in the medium. Either purine deoxyribonucleoside alone or deoxycytidine, hypoxanthine or inosine alone or in combination with deoxyadenosine or deoxyguanosine are ineffective. The results are consistent with the conclusion that the inhibition of DNA synthesis is due to a depletion of the dATP and dGTP pools as a result of the hydroxyurea treatment. On the other hand, hydroxyurea causes an increased incorporation of thymidine and deoxycytidine into the dTTP and dCTP pools, respectively. Evidence is presented to indicate that this effect of hydroxyurea is due to an increased synthesis of dTTP and dCTP rather than to an inhibition of their turnover.
A spoonful of sugar: feedback signals of energy stores and corticosterone regulate responses to chronic stress

To begin to understand the effects of chronic stress on food intake and energy stores, the effects of increased activity in the hypothalamo-pituitary-adrenal (HPA) axis and glucocorticoids (GCs) on the body and brain must first be understood. We propose two major systems that are both GC sensitive: a metabolic feedback that is inhibitory and a direct central GC drive. Under basal conditions, the metabolic feedback signal to brain is dominant, although infusion of GC into a lateral brain ventricle blocks the effects of the metabolic feedback. Chronic stress activates GC secretion and brain nuclear GC receptor occupancy, markedly changing the normal relationships between these two major corticosteroid-activated systems. The stressor-induced switch in the relative strengths of these signals determines subsequent brain regulation of stress responses (behavioral, neuroendocrine and autonomic outflows). The metabolic feedback effects of GCs are mimicked by voluntary sucrose ingestion in adrenalectomized rats, and experiments suggest that the metabolic feedback also inhibits the stressor-induced direct GC drive on brain. We speculate that the interaction between peripheral and central GC-sensitive signaling systems may be coupled through the inhibitory actions of endogenous opiatergic inputs on corticotropin-releasing factor (CRF) neurons.
Phonological Planning during Sentence Production: Beyond the Verb.

The current study addresses the extent of phonological planning during spontaneous sentence production. Previous work shows that at articulation, phonological encoding occurs for entire phrases, but encoding beyond the initial phrase may be due to the syntactic relevance of the verb in planning the utterance. I conducted three experiments to investigate whether phonological planning crosses multiple grammatical phrase boundaries (as defined by the number of lexical heads of phrase) within a single phonological phrase. Using the picture-word interference paradigm, I found in two separate experiments a significant phonological facilitation effect to both the verb and noun of sentences like “He opens the gate”. I also altered the frequency of the direct object and found longer utterance initiation times for sentences ending with a low-frequency vs. high-frequency object offering further support that the direct object was phonologically encoded at the time of utterance initiation. That phonological information for post-verbal elements was activated suggests that the grammatical importance of the verb does not restrict the extent of phonological planning. These results suggest that the phonological phrase is unit of planning, where all elements within a phonological phrase are encoded before articulation. Thus, consistent with other action sequencing behavior, there is significant phonological planning ahead in sentence production.
Evolution of polarization in localized nonlinear Alfvén waves.

A polarization change of localized and finite-amplitude Alfven waves is found by use of both MHD theory and numerical simulation. One of the transverse components of the circularly polarized Alfven wave is stable as it propagates, but the other component is unstable under both self-focusing and diffraction effects. Consequently, the wave changes its polarization from circular to linear.
Mechanism of Nutrient Deprivation Induced Triacylglyceride Accumulation in Alga Indicated by Fluorescence Hyperspectral Imaging

Microalgae have been identified as a promising renewable feedstock for production of lipids for feeds and fuels. For a wide variety of algal species, depletion of major nutrients from the growth medium results in dramatically increased biosynthesis of triacylglycerides, in some cases exceeding 70% of the dry weight of the biomass. In recent work, we explored this process in a number of promising algal production strains (Chlorophyceae and Eustigmophyceae) using hyperspectral confocal fluorescence imaging with multivariate spectral unmixing. By coupling intensity modulation of the excitation laser and attenuation of the dominant chlorophyll fluorescence emission, we identified a distinct spectral component composed of chlorophyll fluorescence and resonance Raman emission for lipid-solubilized carotenoids allowing label-free projections of lipid bodies in addition to plastids. Furthermore, cells exposed to the lipophilic dye, Nile Red, exhibited distinct spectral components corresponding to the polar and neutral lipid fractions. Combining these capabilities for analysis of nutrient deprivation time courses revealed increases in the lipid fraction of the cellular volume of ∼500%, as well as a correlated decrease in the plastid fraction of the total cellular volume. Additionally, diffraction limited tubules connecting the lipids bodies to the plastids and the presence of unbound chlorophyll in the lipid bodies provided evidence for direct shuttling of lipids from the chloroplast to the lipid bodies, in opposition to the expected ER to lipid body transfer dictated by the Kennedy pathway. The results suggest that nutrient deprivation-based lipid accumulation in these species is dominated by plastid membrane recycling, independent of acyl-CoA. Finally, an additional spectral component exhibiting high spectral overlap with Nile Red and varying inversely with the chlorophyll emission was detected during senescence, potentially resulting in false positives for lipid enrichment in low spectral resolution assays.
Mechanisms in homocysteine-induced vascular disease

Hyperhomocysteinemia (HHcy) is a significant and independent risk factor for cardiovascular disease (CVD). It has been reported that lowering plasma homocysteine (Hcy) levels improved endothelial dysfunction and reduced the incidence of major adverse events after percutaneous coronary intervention. We and others have provided experimental evidence supporting the hypothesis that Hcy is a causative factor for atherosclerosis. This article will discuss biological and molecular events related to cardiovascular pathological changes associated with HHcy.
Randomized, comparative efficacy trial of oral penicillin versus cefuroxime for perianal streptococcal dermatitis in children.

OBJECTIVE: To investigate the efficacy of penicillin compared with cefuroxime for group A beta-hemolytic Streptococcus pyogenes (GABHS) perianal dermatitis. STUDY DESIGN: Children 1 to 16 years of age with signs and symptoms of perianal dermatitis and a positive anal swab were randomized to penicillin or cefuroxime treatment and were clinically re-evaluated on day 3 and at the end of treatment (cefuroxime, day 7; penicillin, day 10). An anal swab was obtained to document eradication of GABHS at the end of treatment. Severity of disease was assessed with a clinical score (perianal erythema, 5 points; perianal itch, 3 points; painful defecation, 3 points; constipation, 2 points). RESULTS: Patients were enrolled and randomly assigned to penicillin (n = 18) or cefuroxime (n = 17) treatment. Treatment with penicillin was inferior to cefuroxime, which led to premature study termination after consultation with the ethics committee. Clinical improvement was more rapid in the cefuroxime group (P = .028) and GAHBS was not isolated from the anus the last day of therapy in 13 of 14 patients treated with cefuroxime compared with 7 of 15 patients treated with penicillin (P > .01). CONCLUSIONS: Cefuroxime was more effective than penicillin and therefore should be considered as the treatment of choice for perianal dermatitis due to GABHS.
Influence of the arachidonic acid cascade on the in vitro hepatic response to hypoxia.

Abstract Studies were undertaken to determine the effect of arachidonic acid, the precursor of bisenoic prostanoic acid derivatives, on the response of the isolated, perfused rabbit liver to hypoxia. Two and one half hours of severe hypoxia resulted in significant increases in hepatic vascular perfusion pressure, tissue wet weight, and the rates of cellular loss of lactic dehydrogenase, malic dehydrogenase, and acid phosphatase into the perfusing medium. Hypoxia also increased the rate of hepatic PGF2α production by 25% after 2 1 2 hours (p
Mass effect in quantum mechanical collision-induced dissociation in collinear reactive atom-diatomic molecule collisions

Abstract Quantum mechanical probabilities for collision-induced dissociation (CID) and chemical reactions have been obtained for a model triatomic collinear system, A+BC(ν)→A+BC(ν′), AB(ν″)+C, A+B+C, using hyperspherical coordinates. Details of the methodology used for CID are presented. Calculations were performed for three different symmetric mass combinations (mA=mB=mC,mA=mC≠mB corresponding to light-light-light, heavy-light-heavy, and light-heavy-light systems. CID was found to be enhanced by reagent vibrational energy and to be most likely in the light-heavy-light system and least likely in the heavy-light-heavy system. Vibrationally nonadiabatic processes were found to be of only secondary importance compared with either CID or vibrationally adiabatic ones. The activation energies for CID were found to be substantially in excess of the energetic threshold. The exchange reaction was found to be vibrationally enhanced, with the reagent vibrational excitation being partly effective in lowering the activation energy of thereaction.Quasi-classical trajectory calculations on the light-light-light system performed previously suggest that classical mechanics furnishes an adequate representation of the main features of the dynamics in these systems.
Maternal and child health nutrition training builds leadership skills

For more than 30 years, the Maternal and Child Health Bureau (MCHB) has funded specialized professional training in nutrition with an emphasis on the development of leadership skills. A survey was conducted of individuals who received Maternal and Child Health nutrition training at the Center for Human Development and Disability (CHDD) at the University of Washington. Those surveyed were asked to reflect on the impact of the training on their career pathway and to report on their leadership activities. Of the 91 respondents, 83 (92%) indicated that the training supported a career pathway that emphasized maternal and child health or children with special healthcare needs. Eighty-five former trainees (93% of respondents) reported leadership activities at the local level, 61 (67%) reported leadership activities at the state level, and 46 (51%) reported leadership activities at the national level. The results of the survey indicate that specialized, intensive training in the field of nutrition develops and supports leadership skills.
Synaptic input to the on-off directionally selective ganglion cell in the rabbit retina.

A physiologically identified on-off directionally selective (DS) ganglion cell with its preferred-null axis defined was stained with horseradish peroxidase (HRP) and prepared for electron microscopy. A continuous series of thin sections were used to examine the cell's synaptology. Although the DS cell dendrite received the majority of its synaptic input from a heterogeneous population of amacrine cell processes, a frequently observed synaptic profile consisted of a DS cell dendrite receiving synapses from a cluster of several amacrine cell processes. These clusters of processes were assumed to be from a fascicle of amacrine cells, most of which probably belonged to several different cholinergic starburst amacrine cells. The most frequently observed presynaptic profile within the clusters consisted of a synaptic couplet in which two processes synapsed with each other before one of them finally synapsed with the DS ganglion cell dendrite; occasionally, a chain of three serial synapses was seen. In addition, a specific microcircuit that has the potential to exert lateral feedforward inhibition was also observed. This microcircuit consisted of two cone bipolar cell terminal dyad synapses where one dyad contained an amacrine cell process making a reciprocal synapse and a DS ganglion cell dendrite receiving direct excitation; the other dyad synapse, found lateral to the first dyad, contained two amacrine cell processes that both made reciprocal synapses, but one fed forward to make a putative inhibitory synapse with the DS cell dendrite.
Desensitization of phobias: some psychophysiological propositions.

This study tested twelve hypotheses derived from psychophysiological theory underlying the systematic desensitization method of reducing phobic anxiety. Subjects with phobias imagined threatening scenes and neutral scenes under relaxed or non-relaxed conditions while cardiac, respiratory, digital vasomotor, and skin conductance activity was recorded. Seven hypotheses were confirmed for one or more response measures. The results indicated that (a) imagining threatening scenes produces autonomic arousal in direct proportion to degree of subjective threat associated with the scenes, (b) autonomic reactions do not extinguish and countercondition faster to weak stimuli than to strong stimuli, and (c) muscle relaxation has a demonstrable but limited effect on counteracting autonomic fear reactions. Desensitization theory was partially supported.
Rapid and Quantitative Sizing of Nanoparticles Using Three-Dimensional Single-Particle Tracking

We report the first application of three-dimensional (3D) single-particle tracking (SPT) to hydrodynamic size characterization of gold nanoparticles in water. Nanoparticles undergoing Brownian motion were dynamically locked at the focal point of a microscope objective, one at a time, by rapid counteractive movements of the sample container. The hydrodynamic radius was derived from the recorded trajectory of each individual nanoparticle. The directly measured size and size distribution using 3D-SPT were in agreement with those obtained using the conventional dynamic light scattering (DLS) and using transmission electron microscopy (TEM), respectively.
Pooled Case Comparison: An Innovation for Cross-Case Study

Comparative studies offer a means for developing more robust theory, but they are plagued by problems of decontextualization of data and marginalization of the voices of the researched. This article introduces pooled case comparison, a means of cross-study comparison that has the potential to minimize some of the limitations often inherent in such comparisons. In pooled case comparison, raw data from separate studies are combined for a fresh analysis. This article provides a rationale for pooled case comparison and situates the method within a framework of other approaches. A detailed example from one pooled case comparison is offered. This example, in the form of a playlet, juxtaposes voices of participants from two separate studies. The example illustrates how this particular form of data presentation maintains the centrality and integrity of partici pants' voices within their specific contexts. Finally, the authors consider potential contri butions of pooled case comparison as well as possibilities for...
Pediatric Sub‐specialist Controversies in the Treatment of Congenital Heart Disease in Trisomy 13 or 18

Trisomy 13 and 18 are associated with congenital heart disease. Cardiac palliation has been reported in the literature, but is not usually done in this population. Thus, a multi-disciplinary team may experience controversy in formulating a care plan that includes cardiac intervention. Our objective was to determine differences in recommendations for cardiac intervention in this population between physicians specializing in pediatric cardiac critical care, neonatology, and genetics. A web-based survey was performed between April 2007 and August 2008. This survey evaluated surgical and transcatheter cardiac palliations that had been performed for individuals with trisomy 13 or 18 at the respondent’s institution, the respondent’s recommendations for cardiac intervention in hypothetical symptomatic patients with trisomy 13 or trisomy 18 and the influence of parental preference on these recommendations. Eight hundred fifty-nine responses were obtained from a primarily academic practice setting (59%). Cardiologists were most likely to recommend intervention; low risk interventions were recommended by 32% of cardiologists, 7% of neonatologists and 20% of geneticists. Parental request to intervene resulted in a 3 fold increased in the likelihood of all specialist recommending intervention. Counseling of families frequently occurred by multiple sub specialists (50%) and there was frequently (71%) a difference in opinion. Individuals with trisomy 13 or 18 are receiving cardiac intervention at many institutions. Cardiologists were more likely than geneticists or neonatologists to recommend intervention on all heart lesions other than single ventricle palliation which no specialists recommended. Parental wishes that “everything be done” significantly influenced all specialists’ recommendations.
Anti-interleukin-4 Inhibits Immunoglobulin E Production in a Murine Model of Atopic Asthma

Immunoglobulin E (IgE) plays an important role in allergy, acting as an initiating factor and being involved in its persistence and exacerbations. As interleukin-4 (IL-4) is critical in IgE synthesis, we propose that treatment of mice with monoclonal anti-IL-4 (11B11) prior to active sensitization with ovalbumin will inhibit IgE synthesis, therefore arresting the allergic process at an early stage. Mice treated with 11B11 and sensitized with saline or ovalbumin had significantly less serum IgE than their respective control groups which were treated with saline (p < 0.05). This study suggests that anti-IL-4 may be a prophylactic agent in asthma and allergic disease.
Stacking of the square-lattice antiferromagnetic planes in Ca 2 CuO 2 Cl 2

Single-crystal neutron elastic and quasielastic scattering and magnetization studies of the spin-$\frac{1}{2}$ square-lattice Heisenberg antiferromagnet ${\mathrm{Ca}}_{2}{\mathrm{CuO}}_{2}{\mathrm{Cl}}_{2}$ indicate an unusual stacking of the antiferromagnetic planes in the N\'eel state (${T}_{N}=247\ifmmode\pm\else\textpm\fi{}5\mathrm{K}$) which is different from the collinear stacking in isostructural ${\mathrm{Sr}}_{2}{\mathrm{CuO}}_{2}{\mathrm{Cl}}_{2}$. A generalized magnetic model is presented to describe the data. Elastic scattering along the ($\frac{1}{2}$$\frac{1}{2}$$l$) rod is observed above ${T}_{N},$ suggesting that the ${\mathrm{CuO}}_{2}$ planes, although uncoupled, maintain some degree of two-dimensional order up to a crossover temperature (${T}_{\mathrm{co}}\ensuremath{\approx}280\mathrm{K}$) to the isotropic Heisenberg state. No structural phase transition from the $I4/mmm$ symmetry was observed in the temperature range 10--300 K.
Intraseasonal Dynamical Evolution of the Northern Annular Mode

Abstract The Northern Hemisphere annular mode (NAM) accounts for a significant fraction of the extratropical wintertime atmospheric variability. The dynamics of NAM events have been studied on monthly time scales, but little is known about the physical mechanisms that give rise to NAM variability on shorter time scales. Composite diagnostic analyses based on daily NAM indices are performed with a goal of identifying the dominant processes responsible for the growth and decay of large-amplitude positive and negative NAM events on short intraseasonal time scales. Transformed Eulerian mean, piecewise potential vorticity inversions, and regional Plumb flux diagnoses are employed to deduce the proximate forcings of the zonal-mean wind tendency during maturing and declining NAM stages. A remarkable degree of reverse symmetry is observed between the zonal-mean dynamical evolution of positive and negative NAM events. Anomalous equatorward and downward (poleward and upward) Eliassen–Palm fluxes are observed during...
Enantioreversal in the sharpless asymmetric epoxidation reaction controlled by the molecular weight of a covalently appended achiral polymer.

Polymers such as poly(ethylene glycol) (PEG) have proven use in a variety of applications including organic synthesis. We now disclose our investigations into the recently disputed report that PEG tartrate esters can reverse the enantioselectivity of the Sharpless asymmetric epoxidation reaction. The results presented herein have clarified that the enantioselectivity of this reaction can be reproducibly reversed solely as a function of the molecular weight of the appended PEG. By preparing a range of tartrate ligands with varying PEG chains lengths, the reversal was found to occur within a molecular weight change of only 800. As the PEG chain did not affect the inherent chirality of the ligand, the enantioreversal was proposed to occur as a result of two Ti−ligand complexes which differ in their molecularity of ligand, one monomeric in ligand and the other dimeric. Support for this hypothesis was given through equilibrium measurements which revealed that the predominant species in Ti/PEG tartrate ester mi...
Challenges in using wearable cameras and phone logs to generate ground truth of transportation activities

Researchers have started recruiting users to record activity data with ground truth annotations in real-word settings. These annotations are considered "ground truth" because users who collected activity data probably know what happened during the activity. However, while ground truth annotations are generally believed to be truthful representations of recorded activities, other qualities of activity recordings such as temporal precision are also of researchers' interest. To assess and compare the qualities of annotated recordings collected among different approaches, it is necessary to have another way to capture a ground truth of users' activities. In this paper, we demonstrate how we used wearable cameras and phone logs to assess the quality of users' recorded transportation activity data. We focus on how we collected photos and logs and generated a ground truth of transportation activity data, and we present challenges we encountered in the generation process.
CEO pay for performance sensitivity in the restaurant industry: what makes it move?

ABSTRACT The changing business conditions and the inefficient corporate governance in the restaurant industry turned shareholders' attention to the executive compensation. This study examines determinants of the sensitivity in Corporate Executive Officers' (CEOs) cash compensation. The contribution of this study is that it uses pooled regression and analyzes annual percentage change in CEO cash compensation. The findings revealed that company stock returns and return on assets emerged as significant determinants of CEO pay sensitivity. The results of this study show that almost 90% of the variation in the sensitivity of CEO compensation in the restaurant industry remains unexplained and is left for future research.
Vapor pressures and thermodynamics of oxygen-containing polycyclic aromatic hydrocarbons measured using knudsen effusion†

Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (OPAHs) are ubiquitous environmental pollutants resulting from the incomplete combustion of coal and fossil fuels. Their vapor pressures are key thermodynamic data essential for modeling fate and transport within the environment. The present study involved nine PAHs containing oxygen heteroatoms, including aldehyde, carboxyl and nitro groups, specifically: 2-nitrofluorene; 9-fluorenecarboxylic acid; 2-fluorenecarboxaldehyde; 2-anthracenecarboxylic acid; 9-anthracenecarboxylic acid; 9-anthraldehyde; 1-nitropyrene; 1-pyrenecarboxaldehyde and 1-bromo-2-naphthoic acid. The vapor pressures of these compounds, with molecular weights ranging from 194 to 251 grams per mole, were measured using the isothermal Knudsen effusion technique in the temperature range of 329 to 421. The corresponding enthalpies of sublimation, calculated via the Clausius-Clapeyron equation, are compared to parent, non-oxygenated PAH compound data to determine the effect of the addition of these oxygen-containing heteroatoms. As expected, the addition of –CHO,–COOH, and –NO2 groups onto these PAHs increases the enthalpy of sublimation and decreases the vapor pressure as compared to the parent PAH; the position of substitution also plays a significant role in determining the vapor pressure of these OPAHs.
Neuropsychological substrates and everyday functioning implications of prospective memory impairment in schizophrenia

Individuals with schizophrenia demonstrate impairment in prospective memory (ProM), which describes the multifaceted ability to execute a future intention. Despite its clear implications for everyday functioning, the neuropsychological substrates and functional correlates of ProM impairment in schizophrenia remain poorly understood. In this study, the Memory for Intentions Screening Test (MIST), a standardized measure of ProM, was administered to 72 outpatients with schizophrenia or schizoaffective disorder as part of a comprehensive neuropsychological and psychiatric research evaluation. Results showed that ProM was positively correlated with standard clinical tests of attention, working memory, processing speed, learning, and executive functioning, but not delayed recall. In the context of multiple neuropsychological predictors, learning ability was the only domain that independently contributed to ProM. Importantly, better ProM was predictive of higher functional capacity (as measured by the UCSD Performance-Based Skills Assessment-Brief Version), above and beyond the variability explained by demographic and disease factors. Analysis of component processes revealed that event-based ProM, as well as no response (i.e., omission) and task substitution errors were the strongest predictors of everyday functioning. Overall, these findings suggest that ProM impairment in schizophrenia is associated with multiple cognitive substrates, particularly episodic learning deficits, and plays an important role in everyday living skills. Studies regarding the potential effectiveness of ProM-based remediation strategies to improve functional outcomes in schizophrenia are indicated.
Surface Antigens as Virulence Factors in Infection with Bacteroides fragilis

Organisms of the genus Bacteroides represent the major group of obligate anaerobes involved in human infections. Bacteroides usually cause either bacteremia or localized abscesses. Of the numerous species of Bacteroides, Bacteroides fragilis is the single most frequent clinical isolate. B. fragilis and Bacteroides melaninogenicus have chemically incomplete lipopolysaccharides as compared with the lipopolysaccharides (endotoxins) of aerobic bacteria, and the lipopolysaccharides of Bacteroides lack the biologic potency characteristic of endotoxin. This inactivity may account for the very infrequent occurrence of disseminated intravascular coagulation or purpura that can accompany sepsis due to these organisms. Furthermore, strains of B. fragilis have an immunologically common capsular polysaccharide. In an animal model of intraabdominal sepsis, the encapsulated strains caused abscesses when given without other organisms, but abscess formation from unencapsulated strains of Bacteroides generally required the administration of a synergistic aerobe. The abscesses caused by encapsulated strains were shown to be directly attributable to the capsular polysaccharide, which is an important virulence factor of this organism. Patients or experimental animals infected with B. fragilis develop antibodies to the capsular polysaccharide, and these antibodies can be detected in a radioactive antigen-binding assay.
Degradation of acetonitrile and biphenyl compounds by a mixed microbial culture

A mixed microbial culture was isolated from an environment contaminated with organic cyanides and polychlorinated biphenyls (PCBs). This mixed culture could utilize acetonitrile as the sole source of carbon and nitrogen, and biphenyl as the sole source of carbon. This mixed culture also utilized nitriles, their respective amides, and several PCBs as growth substrates. Studies involving the radiolabeled compounds indicated that nearly 70% of [14C]acetonitrile and 51% of [14C]biphenyl were recovered as 14CO2. The end products resulted during the degradation of acetonitrile and biphenyl were identified as ammonia and benzoate, respectively. It was also observed that the mixed culture that can degrade biphenyl loses its capability when transferred repeatedly into a medium supplemented with acetonitrile as growth substrate. The present study suggests that the application of mixed rather than pure microbial culture is more effective in bioremediation of toxic chemicals.
The Relationship Between Objective Sperm Competition Risk and Men’s Copulatory Interest Is Moderated by Partner’s Time Spent with Other Men

Men who spend a greater proportion of time apart from their female partner since the couple’s last copulation are at greater “objective” sperm competition risk. We propose a novel cue to sperm competition risk: the time she spends with her male friends. Four hundred and twenty men in a committed, heterosexual, sexual relationship completed a questionnaire. The results indicate that men at greater objective sperm competition risk report less time desired until the couple’s next copulation, greater interest in copulating with their partner, and greater anger, frustration, and upset in response to their partner’s sexual rejection, but only among men whose partner spends more time with her male friends. These results remain after controlling statistically for the participant’s age and their partner’s age. We discuss limitations of the current research, and discuss how research in human sperm competition can inform social issues, including men’s partner-directed sexual coercion.
TYPE III PROTEIN SECRETION SYSTEMS IN PLANT AND ANIMAL PATHOGENIC BACTERIA

Among many interesting and sophisticated mechanisms used by bacterial pathogens to subvert eukaryotic hosts is a class of specialized protein secretion systems (known as type III protein secretion systems) that deliver bacterial virulence proteins directly into the host cell. Recent studies have revealed four important features of these secretion systems. First, they are widespread among plant and animal bacterial pathogens, and mutations affecting type III protein secretion often eliminate bacterial virulence completely. Second, at least eight type III secretion components share sequence similarities with those of the flagellar assembly machinery and flagellum-like structures are associated with type III secretion, raising the possibility that these secretion systems are derived from the presumably more ancient flagellar assembly apparatus. Third, type III secretion is activated in vivo upon contact with host cells. Fourth, the type III secretion mechanism is Sec-independent and the effector proteins may possess mRNA-based targeting signals. This review highlights the similarities and differences among type III secretion systems of selected model plant and animal pathogenic bacteria.
A review of radio observations of comets

Abstract The current status of cometary radio observations is reviewed. Radio continuum observations made at different wavelengths can be used to model the properties of cometary particles. Continuum observations have been successful for two comets but the interpretation of the data is subject to some disagreement. Radar observations are important for determining the size, angular momentum, direction of motion, and surface properties of the cometary nucleus. One comet, p/Encke, has been successfully observed by radar. The reasons why radio observations can fail are discussed. These include the undue influence of the highly volatile “comet frost” which often coats new comets, small errors in radio ephemerides, the inopportune scheduling of observing periods at less than optimum cometary heliocentric distances and velocities, and poor spectroscopic properties of the molecular transitions chosen for observations. In order to clarify the sometimes confusing observations which have been reported, cometary radio spectroscopy is reviewed in chronological order, comet by comet, starting from the earliest reported searches for polyatomic molecules in the early 1970s through progress in understanding cometary OH and into current searches for glycine, the simplest amino acid. The results of current OH ultraviolet pumping models are briefly discussed and several formalisms for computing molecular production rates arepresented. Radio observational programs which can aid in discriminating between current theories of terrestrial biological evolution are introduced. Both specific and general conclusions are drawn from the available material on cometary radio spectroscopy.
An introduction to genetic algorithms for electromagnetics

This article is a tutorial on using genetic algorithms to optimize antenna and scattering patterns. Genetic algorithms are "global" numerical-optimization methods, patterned after the natural processes of genetic recombination and evolution. The algorithms encode each parameter into binary sequences, called a gene, and a set of genes is a chromosome. These chromosomes undergo natural selection, mating, and mutation, to arrive at the final optimal solution. After providing a detailed explanation of how a genetic algorithm works, and a listing of a MATLAB code, the article presents three examples. These examples demonstrate how to optimize antenna patterns and backscattering radar-cross-section patterns. Finally, additional details about algorithm design are given. >
Limitations of Using the Incomplete Gamma Function to Generate Egg Production Curves

Abstract Incomplete gamma curves were fitted to data of percent production per week for laying hens by using linear regression to estimate the parameters in the logarithmic transformation of the equation. However, incomplete gamma curves are incapable of predicting an abrupt change from increasing to decreasing production. As a result, predictions of production of laying hens using incomplete gamma curves are highly biased during most of the laying cycle.
CCR7-Dependent Immunity during Acute Toxoplasma gondii Infection

The chemokine receptor CCR7 is a well-established homing receptor for dendritic cells and T cells. Interactions with its ligands, CCL19 and CCL21, facilitate priming of immune responses in lymphoid tissue, yet CCR7-independent immune responses can be generated in the presence of sufficient antigen. In these studies, we investigated the role of CCR7 signaling in the generation of protective immune responses to the intracellular protozoan parasite Toxoplasma gondii. The results demonstrated a significant increase in the expression of CCL19, CCL21, and CCR7 in peripheral and central nervous system (CNS) tissues over the course of infection. Unexpectedly, despite the presence of abundant antigen, CCR7 was an absolute requirement for protective immunity to T. gondii, as CCR7(-/-) mice succumbed to the parasite early in the acute phase of infection. Although serum levels of interleukin 12 (IL-12), IL-6, tumor necrosis factor alpha (TNF-alpha), and IL-10 remained unchanged, there was a significant decrease in CCL2/monocyte chemoattractant protein 1 (MCP-1) and inflammatory monocyte recruitment to the site of infection. In addition, CCR7(-/-) mice failed to produce sufficient gamma interferon (IFN-gamma), a critical Th1-associated effector cytokine required to control parasite replication. As a result, there was increased parasite dissemination and a significant increase in parasite burden in the lungs, livers, and brains of infected mice. Adoptive-transfer experiments revealed that expression of CCR7 on the T-cell compartment alone is sufficient to enable T-cell priming, increase IFN-gamma production, and allow the survival of CCR7(-/-) mice. These data demonstrate an absolute requirement for T-cell expression of CCR7 for the generation of protective immune responses to Toxoplasma infection.
An IUE Atlas of Pre-Main-Sequence Stars. III. Co-added Final Archive Spectra from the Long-Wavelength Cameras

We identified 137 T Tauri stars (TTS) and 97 Herbig Ae/Be (HAEBE) stars observed by IUE in the wavelength interval 1900-3200 A. Each low-resolution (R ~ 6 A) spectrum was visually inspected for source contamination and data quality, and then all usable spectra were combined to form a single time averaged spectrum for each star. For sources with multiple observations, we characterized variability and compared with previously published amplitudes at shorter wavelengths. We combined several co-added spectra of diskless TTS to produce a pair of intrinsic stellar spectra unaffected by accretion. We then fitted spectra of TTS with the reddened sum of an intrinsic spectrum and a schematic veiling continuum, measuring emission line fluxes from the residuals. We used extinction and distance estimates from the literature to convert measured Mg II line fluxes into intrinsic line luminosities, noting that the IUE detection limit introduces a sample bias such that intrinsic line luminosity is correlated with extinction. This sample bias complicates any physical interpretation of TTS intrinsic luminosities. We measured extinction toward HAEBE stars by fitting our co-added IUE spectra with reddened spectra of main-sequence stars and also from V band minus 3000 A color excess. We measured excess line emission and absorption in spectra of HAEBE stars divided by fitted spectra of main-sequence stars, noting that HAEBE stars with an infrared excess indicating circumstellar material typically also have anomalous UV line strengths. In the latter situation, Mg II is usually shallower than in a main-sequence star of the same spectral class, whereas Fe II lines are equally likely to be deeper or shallower. Our co-added spectra of TTS, HAEBE stars, and main-sequence templates are available electronically.
‘Roping the Wild Jitney’: the jitney bus craze and the rise of urban autobus systems

During the economic downturn of 1914, some Los Angeles motorists down on their luck began giving rides at a nickel, or ‘jitney’, per trip and tended to shadow streetcar routes. After some national press attention, this practice became a craze that swept the nation in early 1915. As the jitney experience blossomed into demands for more reliable autobus systems, urbanites began to consider the possibilities of motorized public transit, though they were divided by class and neighbourhood. Suburbanites, however, demanded that cities retool around their automobiles. This article examines the jitney phenomenon as it emerged across the USA, which although handled locally and over varying lengths of time, did lead to a distinct national shift in urban politics and planning. It is argued that the jitney bus was not merely a transition point between rail service and the private automobile. Its real meaning lies in a political shift away from attempts by city dwellers to reform the streetcar trusts, for years a doom...
Performance of a finned-tube evaporator optimized for different refrigerants and its effect on system efficiency *

This paper presents a comparable evaluation of R600a (isobutane), R290 (propane), R134a, R22, R410A, and R32 in an optimized finned-tube evaporator, and analyzes the impact of evaporator effects on the system coefficient of performance (COP). The study relied on a detailed evaporator model derived from NIST’s EVAP-COND simulation package and used the ISHED1 scheme employing a non-Darwinian learnable evolution model for circuitry optimization. In the process, 4500 circuitry designs were generated and evaluated for each refrigerant. The obtained evaporator optimization results were incorporated in a conventional analysis of the vapor compression cycle. For a theoretical cycle analysis without accounting for evaporator effects, the COP spread for the studied refrigerants was as high as 11.7%. For cycle simulations including evaporator effects, the COP of R290 was better than that of R22 by up to 3.5%, while the remaining refrigerants performed approximately within a 2% COP band of the R22 baseline for the two condensing temperatures considered. q 2005 Elsevier Ltd and IIR. All rights reserved.
Neurodegeneration and Vision Loss after Mild Blunt Trauma in the C57Bl/6 and DBA/2J Mouse

Damage to the eye from blast exposure can occur as a result of the overpressure air-wave (primary injury), flying debris (secondary injury), blunt force trauma (tertiary injury), and/or chemical/thermal burns (quaternary injury). In this study, we investigated damage in the contralateral eye after a blast directed at the ipsilateral eye in the C57Bl/6J and DBA/2J mouse. Assessments of ocular health (gross pathology, electroretinogram recordings, optokinetic tracking, optical coherence tomography and histology) were performed at 3, 7, 14 and 28 days post-trauma. Olfactory epithelium and optic nerves were also examined. Anterior pathologies were more common in the DBA/2J than in the C57Bl/6 and could be prevented with non-medicated viscous eye drops. Visual acuity decreased over time in both strains, but was more rapid and severe in the DBA/2J. Retinal cell death was present in approximately 10% of the retina at 7 and 28 days post-blast in both strains. Approximately 60% of the cell death occurred in photoreceptors. Increased oxidative stress and microglial reactivity was detected in both strains, beginning at 3 days post-injury. However, there was no sign of injury to the olfactory epithelium or optic nerve in either strain. Although our model directs an overpressure air-wave at the left eye in a restrained and otherwise protected mouse, retinal damage was detected in the contralateral eye. The lack of damage to the olfactory epithelium and optic nerve, as well as the different timing of cell death as compared to the blast-exposed eye, suggests that the injuries were due to physical contact between the contralateral eye and the housing chamber of the blast device and not propagation of the blast wave through the head. Thus we describe a model of mild blunt eye trauma.
Preliminary examination of cognitive reserve theory in closed head injury.

Abstract This investigation was designed to provide preliminary support for cognitive reserve theory in closed head injury (CHI), and demonstrate the effectiveness of using the Oklahoma premorbid intelligence estimate (OPIE) in research and clinical activities. Out of a possible 124 consecutive referrals, 26 patients (N=26) who underwent neuropsychological assessment following brain injury met study inclusion/exclusion criteria. Participants were included if they had exited post-traumatic amnesia (PTA), demonstrated uncompromised upper extremity use, displayed adequate verbal communication, and were judged capable of completing a full neuropsychological evaluation. Participants were divided into a closed head injury—negative premorbid history (CHI−) or closed head injury—positive premorbid history (CHI+) group based upon premorbid variables (e.g., history of alcoholism). Groups did not differ in terms of demographic variables or premorbid IQ. Despite having less severe head injuries, the CHI+ group had a greater pre–post difference for PIQ, and a significantly larger VIQ/PIQ discrepancy than the CHI− group. In conclusion, these findings suggest that the CHI+ group had diminished cognitive reserve secondary to the aggregate effects of premorbid insult, which resulted in greater cognitive decline following an additional stressor (i.e., CHI) than what might otherwise be expected from the head injury alone.
Why Should Senescence Evolve? An Answer Based on a Simple Demographic Model

Why age? Many single-celled organisms do not undergo either individual or clonal senescence. Moreover there are multicellular organisms which show no aging because lost cells, subcellular organelles, and smaller constituents are continually replaced. It would appear that evolution has simultaneously progressed in two divergent directions. On the one hand, highly evolved species tend, in general, to live longer than primitive ones. On the other hand, most higher forms, at least in the animal kingdom, exhibit aging. Other things being equal, it is clear that long life confers selective advantage on a species. It is much less obvious that aging does so.
Crystal structure of an unusual thioredoxin protein with a zinc finger domain.

Many Gram-negative bacteria have two cytoplasmic thioredoxins, thioredoxin-1 and -2, encoded by the trxA and trxC genes, respectively. Both thioredoxins have the highly conserved WCGPC motif and function as disulfide-bond reductases. However, thioredoxin-2 has unique features: it has an N-terminal motif that binds a zinc ion, and its transcription is under the control of OxyR, which allows it to be up-regulated under oxidative stress. Here, we report the crystal structure of thioredoxin-2 from Rhodobacter capsulatus. The C-terminal region of thioredoxin-2 forms a canonical thioredoxin fold with a central β-sheet consisting of five strands and four flanking α-helices on either side. The N-terminal zinc finger is composed of four short β-strands (S1–S4) connected by three short loops (L1–L3). The four cysteines are at loops L1 and L3 and form a tetragonal binding site for a zinc ion. The zinc finger is close to the first β-strand and first α-helix of the thioredoxin fold. Nevertheless, the zinc finger may not directly affect the oxidoreductase activity of thioredoxin-2 because the zinc finger is not near the active site of a protomer and because thioredoxin-2 is a monomer in solution. On the basis of structural similarity to the zinc fingers in Npl4 and Vps36, we propose that the N-terminal zinc finger of thioredoxin-2 mediates protein-protein interactions, possibly with its substrates or chaperones.