cssi/SciSciGPT-SciSciNet huggingface dataset:
Stochastic simulations of light-scattering noise in two-wave mixing: application to artificial Kerr media

This paper presents an examination of power dissipation in a nonlinear optical medium during the coherent transfer of energy from a pump to a signal beam, and quantitatively relates this dissipation (through the fluctuation-dissipation theorem) to the spectrum of thermal fluctuations that give rise to light-scattering noise. Calculations are presented for two-wave mixing in an artificial Kerr media using a powerful stochastic model for computer simulation of amplitude, phase, and intensity fluctuations due to light-scattering noise.
Waves on the subsolar ionopause of Venus

The subsolar ionopause of Venus is expected to be stable to both the Kelvin-Helmholtz and flute instabilities. However, magnetic profiles obtained in the subsolar region indicate that the surface of the ionopause contains large amplitude corrugations, perhaps incipient flux ropes. A possible mechanism for destabilizing the boundary is suggested by the observation that the ion density does not drop abruptly at the ionopause but continues to decrease smoothly into the magnetosheath.
C-Reactive Protein is Linked to Lower Cognitive Performance in Overweight and Obese Women

Our objective was to ascertain the nature of the associations between C-reactive protein (CRP) and cognition, and to examine how they are affected by gender and obesity. We evaluated 62 females and 63 males between 42 and 82 years of age. There were 20 lean females with a body mass index (BMI) of <25 kg/m2 and 42 overweight or obese females, with BMIs ≥25 kg/m2. There were 14 lean males and 49 with BMIs ≥25 kg/m2. CRP was associated with lower scores on cognitive tests of frontal lobe function among females and these associations were driven by the overweight/obese female group. In these data no associations between CRP and cognition were found among males. Obesity-associated inflammation is much more prominent in females and it appears to be associated with cognitive dysfunction, particularly of frontal lobe tasks.
Hospital Readmission as a Quality Measure in Surgery

The debate aboutwhether hospital readmissions should be used to measure quality is escalating. The renewed interest in this topic comes fromthe recognition that reducing readmissions is a rare example of the elusive goal of simultaneously improving quality and reducingcosts. TheCenters forMedicare&MedicaidServices (CMS) recentlygavereadmissionmeasures increased importanceby implementing substantial financial penalties through the Hospital Readmissions Reduction Program (HRRP). The HRRP began assessing penaltiesofupto3%ofahospital’s totalMedicarepayments forhospitalswithhigher-than-expected risk-adjusted readmission rates for commonmedical conditions, acutemyocardial infarction, pneumonia, and congestive heart failure.1 Whether hospital readmissions are a good measure of quality for these medical conditions is hotly debated. Many argue against using them because readmissions are not correlated with known quality metrics, such as mortality, volume, or process compliance. Others are concerned that readmissions have more to do with the financial and social resources of the patient than theydowith quality of care.1 Proponents argue that readmissions are not correlated with existing quality metrics because they represent a unique domain of quality—coordination of care. In other words, readmission servesasaproxy forhowwell thehospitalpreparespatients for transitioning from one setting to another. With CMS set to expand these penalties to surgical procedures in 2015, a similar argument has arisen in surgery.2 Many have criticized the use of readmissions in surgical populations, but these criticisms are largely based on the same arguments against using readmissions as quality metrics for medical conditions.2 However, there is emerging evidence that medical and surgical readmissions should be considered separately because they may have different root causes. ArecentstudybyMorrisetal3 inJAMASurgerysupports theview that hospital readmissions may indeed be a valid measure of hospital quality in surgery. Likemanyprior studies, the authors showed that patients who experienced a postoperative complication were at higher risk for readmission.4 Importantly, however, the investigatorswere able to study the timingof the complication. The investigators found that 72% of complications occurred prior to disJAMASURGERY
Viral assembly: a molecular modeling perspective

Icosahedral viruses are among the smallest and simplest of biological systems. The investigation of their structures represented the first step toward the establishment of molecular biophysics, over half a century ago. Many research groups are now pursuing investigations of viral assembly, a process that could offer new opportunities for the design of antiviral drugs and novel nanoparticles. A variety of experimental, theoretical and computational methods have been brought to bear on the study of virus structure and assembly. In this Perspective we review the contributions of theoretical and computational approaches to our understanding of the structure, energetics, thermodynamics and assembly of DNA bacteriophage and single-stranded icosahedral RNA viruses.
Thermodynamics and kinetics of solute transfer in reversed-phase liquid chromatography: Effect of annelation in polycyclic aromatic hydrocarbons

A series of four-ring polycyclic aromatic hydrocarbons (PAHs) with varying annelation structure was studied by reversed-phase liquid chromatography. Using a polymeric octadecylsilica stationary phase over a temperature range from 273 to 303 K and an average pressure range from 585 to 3585 psi (1 psi = 6894.76 Pa), the thermodynamic and kinetic aspects of the retention mechanism were examined. Thermodynamic behavior was characterized by the retention factor, together with the associated changes in molar enthalpy and molar volume, whereas kinetic behavior was characterized by the rate constants, together with the associated activation enthalpies and activation volumes. The data indicate that pyrene, with a more condensed annelation structure, exhibits smaller changes in molar enthalpy and molar volume (delta Hsm = -4.4 kcal/mol, delta Vsm = -1.9 ml/mol; 1 cal = 4.184J) than PAHs with a more linear structure such as chrysene (delta Hsm = -8.2 kcal/mol, delta Vsm = - 11.7 ml/mol). The kinetic data indicate that pyrene undergoes faster rates of transport than chrysene (k(ms) = 313 and 14 s(-1), respectively), but the non-planar benzo[c]phenanthrene undergoes the fastest transport (k(ms) = 330 s(-1)). The activation enthalpies and activation volumes are similarly affected by the annelation structure. It is noteworthy that deviations from the exponentially modified Gaussian (EMG) model are observed for some PAH zone profiles at the lowest temperature, which suggests a possible change in retention mechanism. In order to characterize these deviations, the non-linear chromatography (NLC) model and a new bi-exponentially modified Gaussian (E2MG) model were examined. The regression results indicate that neither the NLC nor E2MG model offer significant improvements in the statistical quality of fit or provide a better description of the observed retention behavior.
Study of carbon microstructure by using inverse gas chromatography

Abstract Carbons with different pore structures were studied by means of inverse gas chromatography at infinite dilution and finite concentration. Thermodynamic quantities, such as the enthalpy or the free energy of adsorption, are dependent on the carbon micropore structure. Normal alkanes in conjunction with their branched isomers having different critical diameters were used to assess the molecular sieving properties of the investigated carbons. Chromatographic measurements at finite concentration yielded adsorption isotherms, and from these the isosteric heat of adsorption as a function of amount adsorbed for the parent n-alkane and its isomers were calculated. Both isotherms and isosteric heats of adsorption are consistent with the carbon pore structure.
Random Measurement Error Does Not Bias the Treatment Effect Estimate in the Regression-Discontinuity Design. II. When an Interaction Effect Is Present

This article examines the regression-discontinuity (RD) design when there is random measure ment error and a treatment interaction effect. Two simulation issues -the specification of the pretest-posttest functional form and the choice of the point-of-estimation of the treatment effect- are examined Traditionally, an interaction effect in the general linear model has been con structed after centering the true scores by subtracting their mean. However, because the RD design has traditionally estimated the treatment effect at the cutoff, one is liable to obtain an apparently biased treatment effect that is actually attributable to the misspecification with regard to the point-of-estimation. Formulas are provided that allow one to control exactly in simulations the magnitude of a treatment effect at any point-of-estimation. These formulas can also be used for simulating the randomized experimental (RE) case where estimation is not at the pretest mean.
New Faculty on the Block: Issues of Stress and Support

SUMMARY The research reported investigated the experiences of new faculty in their first three years of employment in higher education administration programs. New faculty face stress relative to work-life integration, issues pertaining to gender or color, teaching responsibilities, and unclear expectations. The findings of this study highlight the role of graduate school socialization and identification as a “chosen” student targeting a faculty position as an influence on new faculty and their acclimation during their first years. Implications include the need for intentional mentoring, inclusive support for all students seeking faculty roles, and the need for specificity on the part of hiring committees and new departments regarding expectations. Key to new faculty success is obtaining a sense of work-life integration.
A method of characteristics and invariant imbedding for distributed control problems

In this paper we will consider those control problems where the external inputs to a distributed system are the control functions. These controls are to be determined in order to satisfy a criterion functional. Using standard techniques (Brogan [5], Sakawa [14], Wang [15]), determination of the solution of such a problem requires knowledge of the Green’s function. Determination of a Green’s function necessitates solving of an associated Sturm Liouville eigen-value problem. This is usually a difficult numerical problem to solve on a digital computer. Alternatively, a direct method using characteristics and invariant imbedding [1] is shown here, for solving certain optimal control problems in distributed parameter systems.
Re: S Gabrysch et al: The role of context: neighbourhood characteristics strongly influence HIV risk in young women in Ndola, Zambia. TMIH 2008, February issue.

Gabrysch et al (2008) reported on the importance of context in our understanding of HIV in Zambia by their secondary analysis and presenting of data. While such direction of focus should be welcomed there are a number of areas where the reader may wish for clarity in conceptualization of the problem and presentation. The first limitation of the analysis is that the authors focus on "neighborhoods" without explicitly giving their definition of the term. Neighborhoods can be demarcated by mere geography by administrative or political criteria by historical attributes or by the study participants own definition of what constitutes their neighborhood. It seems the authors did not sufficiently consider these differences (Diez Roux 2001). In HIV research a neighborhood defined by study participants as the area within which they normally find sexual partners may be conceptually more relevant than an administrative neighborhood such as a census track or township. In Table 2 the authors report male circumcision as a binary variable i.e. >8% and 8%; in which category was 8% which is not reported? It would appear reasonable to dichotomize this variable at the median prevalence of circumcision (for the 16 "neighborhoods") rather than at an arbitrary value. The papers terminology is sometimes imprecise and thus has the potential to limit the readers understanding. For instance neighborhoods are categorized as having "a market nearby" electricity or water uniformly distributed and being located near a health center. Was universal access to water in a neighborhood required for it to be described as having water (versus not)? If not what were the cut-off values? How near is near? Is nearness (by distance) to market similar to nearness to health center? Whose assessment matters - the study participants the interviewers or measurements taken and then categorized at analysis? These are important considerations because if the focus is on context we should be able to hypothesize which risk behaviours an individual is exposed to because of his or her nearness to a community facility. Finally it appears the authors have used aggregate measures to highlight compositional aspects of the "neighborhoods" rather than context (Diez Roux 2001). In the Discussion section there are limited suggestions as to how "contextual" factors such as water and electricity availability closeness to health center or market are related to being HIV-infected. How would being close to a health center affect the risk of infection? Does residence in a poor neighborhood affect ones behaviours? Attention to these concerns would have shed more light on the mediating factors that readers need to consider in a neighborhood study. (full-text)
Long-term follow-up of survivors of childhood cancer

Objective: This study was designed to improve the long-term follow-up of childhood cancer survivors by developing standard monitoring for adverse effects; Providing concise treatment summaries for each patient and identifying already existing adverse effects; Determining patient risks for long-term adverse effects; and providing individualized 10-year of plants for followup.Methods: A retrospective chart review of long-term childhood cancer survivors followed by the institution’s pediatric oncologists was performed. Criteria for review included being at least 5 years from diagnosis and 2 years off chemotherapy. Patients are followed annually by the pediatric oncologists.Results: At the time of review, there were 26 long-term survivors of childhood cancers enrolled at the clinic. Their charts have been reviewed and treatment summaries formulated. Fifty-four adverse effects have been detected. 74% of the patients have long-term adverse effects from receiving cancer therapy. The most common were growth hormone deficiency, hypothyroidism, seizures, and hearing loss. Ten year follow-up plans have been devised for each patients.Conclusion: The presence of long-term adverse effects is common in childhood cancer survivors. The pediatrician is pivotal in helping assure their patients are receiving adequate follow-up to detect these complications as well as assisting in the transition to care as an adult.
Scaling analysis of gas-liquid two-phase flow pattern in microgravity

A scaling analysis of gas-liquid two-phase flow pattern in microgravity, based on the dominant physical mechanism, was carried out with the goal of predicting the gas-liquid two-phase flow regime in a pipe under conditions of microgravity. The results demonstrated the effect of inlet geometry on the flow regime transition. A comparison of the predictions with existing experimental data showed good agreement.
Multipole radiation from massive fields: Application to binary pulsar systems.

A general multipole expansion for radiation from massive vector and scalar fields is developed for periodic sources. This formalism is then combined with data on the binary pulsar PSR 1913+16 to set limits on the electric charge of astrophysical bodies, and on the coupling strengths of new weak forces.
Studies on translocation of immunoglobulins across intestinal epithelium.

We tested the hypothesis that the secretion of IgA into intestinal fluids is modulated by increases in epithelial cell cyclic AMP. Cholera enterotoxin instilled into intestinal loops of rabbits did not induce IgA secretion, even though an appropriate fluid response was obtained. The findings, therefore, do not support the hypothesis.
A Hybrid Prognostic Model Formulation and Health Estimation of Auxiliary Power Units

Prognostic health monitoring is an important element of condition-based maintenance and logistics support. The accuracy of prediction and the associated confidence in prediction greatly influence overall performance and subsequent actions either for maintenance or logistics support. Accuracy of prognosis is directly dependent on how closely one can capture the system and component interactions. Traditionally, such models assume a constant and univariate prognostic formulation-that is, components degrade at a constant rate and are independent of each other. Our objective in this paper is to model the degrading system as a collection of prognostic states (health vectors) that evolve continuously over time. The proposed model includes an age dependent deterioration distribution, component interactions, as well as effects of discrete events arising from line maintenance actions and/or abrupt faults. Mathematically, the proposed model can be summarized as a continuously evolving dynamic model, driven by non-Gaussian input and switches according to the discrete events in the system. We develop this model for aircraft auxiliary power units, but it can be generalized to other progressive deteriorating systems. The system identification and recursive state estimation scheme for the developed non-Gaussian model under a partially specified distribution framework has been deduced. The diagnostic/prognostic capabilities of our model and algorithms have been demonstrated using simulated and field data.
Radiographic evaluation of the free jejunal graft

Jejunal autotransplantation is an increasingly popular method of reconstructive surgery for the upper aerodigestive tract following laryngopharyngectomy. From 1977 to 1985, 55 free jejunal grafts were performed on 49 patients. Thirty patients (61%) experienced reconstructive complications including graft failure in 6, fistula in 18, and strictures in 10. Postoperative dysphagia occurred in 26 patients (53%). The cause of the dysphagia is often complex and related to a number of factors that are discussed. While jejunal autotransplantation is successful in selected patients, complications are not infrequent. The radiologist plays an important role in the evaluation and follow-up of these patients.
Dentifrice Detergent: Its Effect on Human Enamel

A scanning and transmission electron microscope study has shown that human enamel specimens treated with a mild detergent solution exhibit etching of the enamel surface. The tooth surfaces subsequently show a greater susceptibility to the acid attack than samples treated with mineral acid alone. The evidence suggests that reevaluation of sodium dodecyl sulfate and similar detergents as components of commercially available dentifrice products may be necessary.
Creation And Healing Of Vascular Lesions Produced By A Mid-Infrared Laser

Pulses of laser light in the 2 micron range should ablate tissue in a manner similar to the 10.6 micron CO 2 laser with the added advantage of efficient transmission through flexible quartz fibers. We performed an evaluation of a pulsed 2.15 micron laser system with regard to the laser's potential for atherosclerotic vascular applications. In vitro, we lasered fresh human calcific atherosclerosis. Approximately 10 pulses of the THC:YAG at 900 mJ/pulse penetrated a 5 mm thick plaque and caused approximately 80 micron depth of thermal damage. For the in vivo testing, fourteen rabbits underwent aortotomy and backwall exposure to 5 pulses of the THC:YAG laser at 450 millijoules per pulse in order to evaluate the thrombogenic and healing potential of 2.15 micron lasered vessel walls. At time of sacrifice, all aortas were patent. Immediately after treatment, a 60-80 micron deep area of dessicated tissue surrounded the lasered crater. A 40 micron thick thrombi covered the damaged tissue. Healing of the lasered tissue consisted of neovascularization and fibroblast ingrowth from the periphery as well as endothelial cell ingrowth from the surrounding intima. Our results indicate that the pulsed 2.15 micron THC:YAG system deserves further consideration for angioplasty applications.
Liquid chromatographic determination of biotin in multivitamin-multimineral tablets.

A reproducible reverse phase high pressure liquid chromatography (RP-HPLC) method for the determination of biotin in multivitamin-multimineral tablets has been developed and validated. This method involves reverse phase separation of the component monitored by absorbance at 200 nm wavelength. The method has excellent precision and accuracy with S.D. 0.83 and 2.9%, respectively. The established linearity range was 0.5-2 micrograms ml-1 (r2 > 0.9999). The recovery of biotin from spiked placebo was > 97% over the linear range. The extraction procedure is simple and the HPLC conditions separate biotin from its degradation products and excipients. The method has been successfully used in determining biotin content in 4 brands of commercially available multivitamin-multimineral tablets.
Identification of catalytic amino acids in the human GTP fucose pyrophosphorylase active site.

GTP-l-fucose pyrophosphorylase(GFPP) catalyzes the reversible formation of the nucleotide-sugar GDP-β-l-fucose from guanosine triphosphate and β-l-fucose-1-phosphate. The enzyme functions primarily in the mammalian liver and kidney to salvage free fucose during the breakdown of glycoproteins and glycolipids. GFPP shares little primary sequence identity with other nucleotide-sugar metabolizing enzymes, and the three-dimensional structure of the protein is unknown. The enzyme does contain several sequences that could be nucleotide binding sites, but none of them are an exact match to consensus sequences. Using a combination of site-directed mutagenesis and UV photoaffinity cross-linking, we have identified five amino acid residues that are critical for catalysis. Some of these amino acids are found within the poorly conserved nucleotide binding consensus structures, while others represent new motifs. Two active site lysines can be cross-linked to photoaffinity probes. The site of cross-linking depends on th...
CHARACTERIZATION OF THE HYDROGEN PEROXIDE-ENZYME REACTION FOR TWO CYTOCHROME C PEROXIDASE MUTANTS

The bimolecular reaction between Escherichia coli-produced cytochrome-c peroxidase (CcP(MI)) and hydrogen peroxide is identical to that of native yeast cytochrome-c peroxidase (CcP) and hydrogen peroxide in the neutral pH region. Both enzymes have pH-independent bimolecular rate constants of 46 microM-1.s-1 for the reaction with hydrogen peroxide. A second mutant enzyme, E. coli-produced cytochrome-c peroxidase mutant with phenylalanine at position 191 (CcP(MI, F191)), has a pH-independent bimolecular rate constant for the hydrogen peroxide reaction of 65 microM-1.s-1, 40% larger than for CcP or CcP(MI). The initial peroxide-oxidation product of CcP(MI, F191) is an oxyferryl porphyrin pi-cation radical intermediate in contrast to the oxyferryl amino-acid radical intermediate formed upon oxidation of CcP or CcP(MI) with hydrogen peroxide. The reactions of all three enzymes with hydrogen peroxide are pH-dependent in KNO3-containing buffers. The reactions are influenced by an ionizable group, which has an apparent pKa of 5.4 in all three enzymes. The enzymes react with hydrogen peroxide when the ionizable group is unprotonated. Both CcP(MI) and CcP(MI, F191) have slightly smaller pH stability regions compared to CcP as assessed by the hydrogen peroxide titer and spectral analysis. The alteration in structural stability must be attributed to differences in the primary sequence between CcP and CcP(MI) which occur at positions -2, -1, 53 and 152.
Hyperspectral data discrimination methods

Hyperspectral data provides spectral response information that provides detailed chemical, moisture, and other description of constituent parts of an item. These new sensor data are useful in USDA product inspection. However, such data introduce problems such as the curse of dimensionality, the need to reduce the number of features used to accommodate realistic small training set sizes, and the need to employ discriminatory features and still achieve good generalization (comparable training and test set performance). Several two-step methods are compared to a new and preferable single-step spectral decomposition algorithm. Initial results on hyperspectral data for good/bad almonds and for good/bad (aflatoxin infested) corn kernels are presented. The hyperspectral application addressed differs greatly from prior USDA work (PLS) in which the level of a specific channel constituent in food was estimated. A validation set (separate from the test set) is used in selecting algorithm parameters. Threshold parameters are varied to select the best Pc operating point. Initial results show that nonlinear features yield improved performance.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Conversational Listening Span: A Prosposed Measure of Conversational Listening

Abstract There is lack of agreement as to what constitutes listening, and this has spawned over 50 definitions and models for listening (Glenn, 1989; Witkin, 1990), but not one testable theory. Most models and definitions were developed in the early 1970s, when listening researchers grounded their work in the popular attention and memory theorists of the day. These theorists proposed linear attention and memory models with the notion of short-term memory/long-term memory (Driver, 2001). However, no definition or model is grounded in working memory theory (WM), introduced by Baddeley and Hitch (1974), which is the dominant theoretical paradigm of attention and memory research. WM theory posits a fixed-capacity system accounting for both processing and storage functions. This study (N = 26) introduces the Conversational Listening Span instrument, the first relational listening instrument grounded in working memory theory. Scores are compared to traditional language-processing span tasks used to measure work...
Local Linear Convergence of an Outer Approximation Projection Method for Variational Inequalities

This paper considers an outer approximation projection method for variational inequalities, in which the projections are not performed on the original set that appears in the variational inequality, but on a polyhedral convex set defined by the linearized constraints. It shows that the method converges linearly, when the starting point is sufficiently close to the solution and the step lengths are sufficiently small.
Scientific foundation, organization structure, and performance of biotechnology and pharmaceutical firms

Abstract Technologists seek to advance practical applications of science while scientists seek to advance knowledge which may or may not have a practical application. Firms with a stronger basic science focus, e.g. biology and chemistry, seek to advance their scientific knowledge foundation in addition to developing and selling innovative products. Firms with a more highly applied science foundation (medicine, engineering, etc.) prioritize the development and sale of innovative products. Combining an Absorptive Capacity (AC) approach with Transaction Cost Economics (TCE) this study explores and explains how firms gain knowledge and perform given their scientific focus. Findings indicate that firms with a stronger basic science orientation are less profitable than firms with a stronger applied science orientation. Applied science firms had more acquisitions and cooperative organizations but both types of firms were more likely to acquire other firms in their quest to build knowledge stores rather than partner. Partnerships with universities were more prevalent among basic science firms than with applied science firms.
Conditioned aversion after delay place conditioning with amphetamine.

Abstract Male, Sprague-Dawley rats received subcutaneous injections of either dextroamphetamine sulfate (AMP; 3.0 mg/kg) or vehicle [VEH (phosphate buffer); 1 ml/kg] immediately before (standard conditioning) or after (delay conditioning) conditioning sessions in a place-conditioning paradigm. AMP was paired for 4 conditioning sessions with one compartment of a three-compartment place-conditioning apparatus; VEH was paired for 4 conditioning sessions with another compartment. Animals were then tested for place preference or aversion by determining the proportion of time spent in each compartment during a 15-minute test session. Standard conditioning with AMP produced a place preference while delay conditioning produced a place aversion. Similar findings had earlier been reported from studies involving conditioned place preferences and aversions with nicotine. These studies demonstrated that the time of drug administration can be as strong a determinant of place-conditioning effects as the drug itself.
Skin absorption from patch test systems

The development of topical drug products requires testing for skin toxicology reactions. A variety of patch test systems are available with which chemicals are applied to skin. The purpose of this study was to determine the skin absorption of paraphenylenediamine (PPDA) from a variety of such systems. [14C]-PPDA (1% pet., USP) was placed in a variety of patch test systems at a concentration normalized to equal surface area (2 mg/mm2). Skin absorption was determined in the guinea pig by urinary excretion of 14C. There was a six-fold difference in the range of skin absorption (p less than 0.02). In decreasing order, % skin absorption from the systems were Hill Top Chamber (53.4 +/- 20.6) greater than Teflon Control patch (48.6 +/- 9.3) greater than Small Finn Chamber with paper disc insert (34.1 +/- 19.8) greater than Small Finn Chamber (29.8 +/- 9.0) greater than Large Finn Chamber (23.1 +/- 7.3) greater than AL-Test Chamber (8.0 +/- 0.8). Thus, the choice of patch system could produce a false negative error if the system inhibits skin absorption, with a subsequent skin toxicology reaction.
Factors that Affect Development of Collar Rot on Tobacco Seedlings Grown in Greenhouses.

Gutierrez, W. A., and Shew, H. D. 2000. Factors that affect development of collar rot on tob acco seedlings grown in greenhouses. Plant Dis. 84:1076-1080. Collar rot, caused by Sclerotinia sclerotiorum, is an important disease of tobacco transplants produced under greenhouse conditions. Factors that affect the development of the disease were studied, including age of seedlings, presence of an external source of nutrients (leaf extract), clipping (leaf removal) practices, exposure to low temperature, and leaf injury caused by heat and a chemical. Flue-cured tobacco seedlings, cultivar K- 326, were grown in polystyrene cell trays floating on a nutrient solution. Trays were maintained in a phytotron growth chamber with a 28/18°C day/night temperature regime. Seedlings were inoculated with ascospores of S. sclerotiorum at the desired stage of growth by placing mature apothecia in the growth chamber and inducing ascospore release and deposition. Disease incidence was determined by examining seedlings for the presence of stem lesions over the next 15 to 21days. Seedlings between 35 and 53 days old were more susceptible to collar rot than younger or older seedlings. Inoculum efficiency was highest and disease was most severe when an external source of nutrients was present on leaf surfaces. Clipping of leaf tips did not increase disease, but if the leaf pieces created by clipping were left on seedlings, collar rot development was enhanced compared with treatments where debris was removed. Heat and chemical injuries that resulted in necrotic tissue provided highly susceptible infection courts for ascospores of S. sclerotiorum, but exposure to low temperature, which caused no visible injury, did not enhance infection. Adoption of cultural practices that minimize accumulation of leaf debris and eliminate factors that cause necrotic injury on leaves should greatly reduce the severity of collar rot of tob acco seedlings.
The geologic evolution of Ganymede and its implications for the origin of the Ganymede-Callisto “dichotomy”

Abstract Old dark terrains on both Ganymede and Callisto were affected by similar endogenic processes, volcanic and (on Ganymede) extensional tectonic modification of multiringed impact structures. The two bodies' evolutions subsequently diverged when younger grooved and light terrains formed only on Ganymede. On the basis of the morphology and geometry of Ganymede's tectonic features, it is inferred that this divergence occurred as the interior of that satellite warmed from an initially cold, undifferentiated state. At least two paradigms of the origin of the divergence are consistent with the interpretations and inferences summarized herein: Ganymede possessed an “accretional trigger” which Callisto did not, or Ganymede's style of mantle convection changed radically as the satellite warmed but Callisto's style of convection did not.
Relationship between thyroid peroxidase T cell epitope restriction and antibody recognition of the autoantibody immunodominant region in human leukocyte antigen DR3 transgenic mice.

We investigated the relationship between thyroid peroxidase (TPO) antibody and T lymphocyte epitopes in TPO-adenovirus (TPO-Ad) immunized BALB/c mice and mice transgenic for the human class II molecule DR3 associated with human thyroid autoimmunity. TPO autoantibodies are largely restricted to an immunodominant region (IDR). BALB/c mice immunized with fewer (107 vs. 109) TPO-Ad particles developed TPO antibodies with lower titers that displayed greater restriction to the IDR. However, as with higher-dose TPO-Ad immunization, T cell epitopes (assessed by splenocyte interferon-γ response to TPO in vitro) were highly diverse and variable in different animals. In contrast, DR3 mice immunized the higher TPO-Ad dose (109 particles) had high TPO antibody levels that showed relative focus on the IDR. Moreover, T cell epitopes recognized by splenocytes from DR3 mice showed greater restriction than BALB/c mice. Antibody affinities for TPO were higher in DR3 than in BALB/c mice. The present study indicates that weak...
The Chaplain Profession from the Employer Perspective: An Analysis of Hospice Chaplain Job Advertisements

Hospitals and hospice organizations who are hiring chaplains to provide spiritual care for terminally ill patients post online job advertisements with specific qualifications and communication skills that applicants should possess. An examination of job advertisements can uncover trends in credentials and responsibilities expected of hospice chaplains. Results of a framework analysis of 71 hospice chaplain job advertisements indicated that 44% of chaplain job advertisements did not require chaplain applicants to have completed clinical pastoral education (CPE) and 41% did not required ordination and/or endorsement from a recognized denomination. Only 37% of hiring organizations required or preferred professional certification. Furthermore, patient support (70%), ambassadorship (54%), team collaboration (52%), and interfaith proficiency (46%) were the communication skills that advertisements tended to emphasize. This article focuses on how the study findings reflect ongoing challenges for the chaplain occupational group on its path to professionalization.
Correlation between enzyme activities and routine metabolic rate in Drosophila

To determine whether enzyme activity is correlated with physiological performance, we analysed the relationship between routine metabolic rate and published data on activity of 12 enzymes from nine species of Drosophila. The enzymes are involved in several aspects of intermediary metabolism including glycolysis. Multiple regression on phylogenetically independent contrasts revealed significant and positive correlations between in vitro enzyme activity and routine metabolic rate. The regression analysis included body size and locomotor activity level as covariates. This result suggests that there may be energetic costs associated with increased enzyme capacity.
Fabrication and Modeling of an Electrospun Tri-Polymer Composite for the Engineering of Fibrous Tissues

Aligned, electrospun scaffolds are a useful tool for the engineering of fiber-reinforced tissues (such as tendon, meniscus, and muscle) as they mimic the topography and anisotropy of the native tissue extracellular matrix (ECM) [1]. We have shown that fiber-alignment of slow-degrading poly(e-caprolactone) (PCL) enhances the organization of newly-formed ECM and improves construct properties [2]. However, one significant drawback to these 3D templates is their small pore size, resulting from tight fiber packing, which hampers cell infiltration. To increase scaffold porosity and thereby accelerate cell ingress, we have recently reported on the fabrication of dual polymer composite scaffolds containing both water-soluble poly(ethylene oxide) (PEO) and PCL fibers [3]. Removal of the sacrificial PEO fibers before seeding improved cell infiltration, but did so at the cost of the overall structural integrity. To further expand the potential properties (mechanics and degradation) of these composite scaffolds, this study introduced a third component (50:50 poly(lactic-co-glycolic acid) (PLGA)) using a newly constructed tri-polymer electrospinning device. We evaluated each polymer singly and when combined into a tri-polymer (3P) fibrous network. To better understand the mechanical response of these composites, we used a hyperelastic, constrained mixture model to assess and predict the response of these composite nanofibrous meshes for a range of compositions.Copyright © 2008 by ASME
Network reliability with node failures

Given a graph whose edges never fail but whose nodes fail independently of each other with a constant probability 1 − p, the reliability of a graph is defined to be the probability that the induced subgraph of the surviving nodes is connected. Let Ω (n, m) be the class of all graphs with n nodes and m edges. A graph G of Ω is said to be uniformly best in Ω, if for all choices of p, it is most reliable in the class of graphs, Ω. In this paper, the existing known set of uniformly best graphs is extended, and some closely related graphs are proved to be not the uniformly best graphs in their class. More precisely, we prove that for any positive integer b the complete tripartite graph K(b, b + 1, b + 2) is uniformly best in its class Ω(3b + 3, 3b2 + 6b + 2), while the complete tripartite graphs K(b, b + 1, b + i)(i > 2) are not the uniformly best in their classes Ω(3b + i + 1, 3b2 + 2(i + 1)b + i). © 2000 John Wiley & Sons, Inc.
Cyclic AMP-dependent protein kinase activity and synaptosomal protein phosphorylation in the brains of aged rats.

— The activity of soluble protein kinase and phosphorylation of endogenous synaptosomal proteins were studied in vitro, in the hippocampus and cerebral cortex of rats 3, 12, or 24 months of age. No between-age differences in the activity of cyclic AMP-dependent or independent protein kinase were detected in either brain region. The degree of stimulation by cyclic AMP and the apparent Ka, for cyclic AMP were similar at all stages. Cyclic AMP stimulated the phosphorylation of synaptosomal proteins from the cerebral cortex, hippocampus, caudate nucleus, and cerebellum of rats at all ages. There were no significant differences across age in the extent of phosphorylation of any membrane proteins in any brain region. The number and staining density of synaptosornal proteins separated by polyacrylamide gel electrophoresis were also similar at all ages. These studies indicate that the cyclic AMP-dependent phosphorylation system in the rat brain does not change during advanced aging.
Waste Storage in the Vadose Zone Affected by Water Vapor Condensation and Leaching

One of the major concerns associated with waste storage in the vadose zone is that toxic materials may somehow be leached and transported by advecting water down to the water table and reach the accessible environment through either a well or discharge to a river. Consequently, care is taken to provide barriers over and around the storage sites to reduce contact between infiltrating water and the buried waste form. In some cases, it is important to consider the intrusion of water vapor as well as water in the liquid phase. Water vapor diffuses through porous material along vapor pressure gradients. A slightly low temperature, or the presence of water-soluble components in the waste, favors water condensation resulting in leaching of the waste form and advection of water-soluble components to the water table. A simple analysis is presented that allows one to estimate the rate of vapor condensation as a function of waste composition and backfill materials. An example using a waste form surrounded by concrete and gravel layers is presented. The use of thermal gradients to offset condensation effects of water-soluble components in the waste form is discussed. Thermal gradients may be controlled by design factors that alter the atmosphericmore » energy exchange across the soil surface or that interrupt the geothermal heat field. 7 refs., 2 figs., 1 tab.« less
Cholinergic mechanisms in the nucleus tractus solitarii and cardiovascular regulation in the rat

Abstract To determine the role played by cholinergic neurons in cardiovascular regulation by the nucleus tractus solitarii (NTS), microinjections (0.1 μ1) of acetylcholine (ACh) or carbachol (C) were made into the NTS of rats, and the changes in arterial pressure and heart rate were recorded. The dose-dependent hypotension and bradycardia which resulted were mediated by the activation of muscarinic, but not nicotinic, receptors confined to the NTS. Blockade of muscarinic receptors bilaterally in the NTS resulted in mild hypertension and attenuated, but did not abolish, the baroreceptor reflex. Eserine, injected into the NTS, augmented and prolonged the action of acetylcholine and slightly increased the maximal baroreceptor reflex response. Thus, cholinergic mechanisms in the NTS tend tonically to lower arterial pressure and may modulate the baroreceptor reflex, without being an integral part of the reflex arc.
In Search of HL Tauri

We present infrared polarimetric images that demonstrate that the T Tauri star HL Tau is not seen in direct light at λ ≤ 2.2 μm. The position of the intensity centroid moves monotonically southwest from V (0.555 μm) through J (1.25 μm) and H (1.65 μm) to K (2.2 μm) wave bands. Furthermore, the mean position of the J, H, and K polarimetric centroids—which marks the position of the illuminating source of extensive reflection nebulosity—is displaced ~1'' southwest of the position of the K-band intensity peak. This offset is in the same direction as the offset between the K-band intensity peak and the centroid of previously detected 3.6 cm emission. We conclude that, at optical and near-IR wavelengths, all of the observed radiation is scattered light from the circumstellar nebula. Our polarimetric images of HL Tau show a "polarization disk" at PA 134° and therefore support a model in which the projection of the equatorial plane of the protoplanetary disk is aligned at PA 134°. These results reinforce the contention that HL Tau is younger and more deeply embedded than typical T Tauri stars.
Role of biogenic silica in the removal of iron from the Antarctic seas

Iron plays a key role in controlling biological production in the Southern Ocean, yet mechanisms regulating iron availability are not completely understood. Here, Ingall et al. show that structural incorporation of reduced, organic iron into biogenic silica represents a new and substantial removal pathway.
Effects of sea-state on the physical performance of a survey bottom trawl

Abstract The effects of sea-state induced vessel motion on the physical performance of the Northeast Fisheries Science Center Yankee 36 survey bottom trawl, rigged with a roller footrope, were investigated. The trawl was instrumented with an acoustic net mensuration system to measure horizontal spread, a head rope mounted acoustic current meter to measure flow at the trawl-mouth, and five sled-mounted inclinometer sensors attached to the wings, quarters and center of the footrope to measure bottom-contact. A vessel motion sensor fixed at the center of the vessel measured roll and pitch. Trawl performance was observed over wave heights of 1–4 m. Vessel motion caused by waves at the sea-surface had a strong effect on trawl motion on the seabed. Vessel heading in relation to wave direction is an influential factor dictating the specific vessel motions occurring in a given sea-state. Of the measured components of vessel motion, pitch had the greatest affect on trawl performance. The speed of vertical stern motion, derived from pitch angles, rather than the magnitude of vertical stern displacement, was the most influential factor controlling variations observed in the footrope bottom-contact data and forward trawl velocity component measured by the current meter. Vertical stern motion speeds of 48 cm/s and greater caused the survey trawl to surge forward and exacerbated the loss of footrope bottom-contact. Since sea-surface conditions had a strong influence on net behavior, it may alter the catch efficiency of a survey trawl, we recommend fish behavior in response to trawl motion be investigated further.
Thermal electron detachment rate constants for azulene− at atmospheric pressure by the photodetachment-modulated electron capture detector

Abstract The direct measurement of rate constants kd for the thermal electron detachment of a polyatomic negative ion has been previously reported on only one occasion—for the azulene negative ion (Az−) by pulsed high-pressure mass spectrometry (PHPMS) at 4 torr total buffer gas pressure over the temperature range 140–200°C. We report here measurements of kd for Az− at a pressure of 2 atm over the temperature range 130–190°C, using a recently developed technique called the photodetachment-modulated electron capture detector (PDM-ECD). This method is based on the competition which exists in the PDM-ECD for destruction of Az− by three processes: thermal electron detachment, photodetachment and ion-ion recombination. The kd values for Az− reported here are found to be somewhat lower, about one-third as great at a given temperature, than those of the previous study. These differences in the two sets of kd measurements suggest the existence of a small but significant pressure dependence which causes kd to be slightly lowered by a 400-fold increase in buffer gas pressure. It is also recognized, however, that a systematic error in the treatment of PDM-ECD data may exist, owing to limitations of current knowledge concerning the rates of ion—ion recombination reactions at near-atmospheric pressures. The complete UV-vis photodetachment spectrum of Az− is also reported here and is shown to bear very strong resemblance to the condensed phase absorption spectrum of Az−.
Building "Nuestra América:" national sovereignty and regional integration in the americas

This article explores the history of regional integration in the Americas, drawing lessons from the diverse ways that people have sought to unite the hemisphere. It begins at the point when most of the modern nation-states of Latin America came into being: the nineteenth-century wars for independence. From there, it traces various attempts at regional integration, keeping in mind three fundamental questions: How does regional integration compromise sovereignty? Does it have to? Is it worth sacrificing sovereignty to increase integration? The article concludes that while every attempt at regional integration in the Americas has required the participants to voluntarily sacrifice some measure of their sovereignty, the most successful efforts have been those that either kept the sacrifice to a minimum or offered significant enough rewards to offset the loss of sovereignty.