cssi/SciSciGPT-SciSciNet huggingface dataset:
The Role of Weak Interactions in Biological Systems: the Dual Dynamics Model

The dual dynamics model is a random autonomous network of nodes whose dynamical behavior is determined by both strong and weak interactions. The model combines discrete decision-making features reflective of logical operations with arithmetic features that represent graded influences. Dual dynamics abstracts the ubiquitous fact that biological systems at all levels of organization consist of components that respond both to specific (strong) signals and to the cumulative effect of numerous weak interactions. We have thoroughly studied the dynamical characteristics of three-valued dual dynamics networks in the range from four to 14 nodes and have compared these characteristics to those of non-boolean three-valued networks (without weak interaction) and to Kauffman boolean networks. Properties studied include: attractor length, number of attractors, basin sizes, orbital stability, and evolutionary transformability in response both to individual and cumulative mutations (where mutations are implemented as random changes in the response of a node to the pattern of strong influences impinging on it). The introduction of weak interactions and their manner of coupling to strong interactions has major altering effects on these properties. With suitable coupling it is possible to significantly enhance equifinality and evolutionary transformability. The model demonstrates that self-organizing dynamics are compatible with evolutionary plasticity when weak interactions are taken into account.Copyright 1998 Academic Press
Efficacy of Retrograde Endopyelotomy in Children

AbstractPurpose: Endopyelotomy has been performed extensively in adults for the treatment of ureteropelvic junction obstruction. To determine its applicability to the pediatric population we reviewed our experience with retrograde endopyelotomy in children.Materials and Methods: Eight children 4 to 15 years old were treated with retrograde endopyelotomy and results were compared to those of a concurrent group of 8 treated with open pyeloureteroplasty.Results: Retrograde endopyelotomy was done in all of our patients with lower ureteral dilatation (as an adjunct measure in 5). Seven patients had symptomatic and radiographic improvement. The patient in whom the procedure failed had a crossing lower pole vessel. Postoperative analgesia, length of hospitalization and cost were lower in the endopyelotomy group.Conclusions: Retrograde endopyelotomy is feasible in children older than age 4 years and it results in reduced morbidity. The success rate is high but open surgery remains the standard, particularly when ...
Office-Based Procedures for Unusual Impactions

The order of frequency of tooth impaction includes mandibular and maxillary third molars, maxillary canines, mandibular premolars, mandibular canines, maxillary premolars, maxillary central incisors, maxillary lateral incisors, and mandibular second molars. Treatment of supernumerary teeth or impacted teeth should be based on clinical symptoms, location of the teeth, and a comprehensive examination of the impact of these teeth on neighboring teeth. In most cases, a diagnosis of supernumerary or impacted teeth is based on clinical symptoms and radiographic examination; the most common diagnoses are made by panoramic, occlusal, and periapical radiographs. Most unusual impacted teeth may be reached by the direct surgical approaches used to remove the commonly impacted sites, often requiring extensions of flaps and the removal of more bone.
Effects of Iontophoresis and Chemical Enhancers on the Transport of Lidocaine and Nicotine Across the Oral Mucosa

Purpose To analyze the effects of chemical enhancers and iontophoresis on the buccal transmucosal delivery of lidocaine and nicotine.
Nutrients and the human genome: New frontiers for the next century

Nutritional individuality in humans may be governed by genomic makeup as well as by phenotypic response to specific micronutrients. As a result of the global Human Genome Initiative, it is anticipated that by 2000, the 100,000 genes in the human genome will have been mapped. Nuclear receptors, their physiological ligands, and their target genes act in concert to influence a wide range of morphogenetic and functional elements. Consequently, genetically determined nutritional individuality could conceivably redefine nutrient requirement for diverse population groups. Incorportation of nutrition-related studies in the Human Genome Initiative may facilitate the practical application of genome data to the alleviation of human problems. 11 refs.
A STUDY OF ACID MINE DRAINAGE USING EARTH RESISTIVITY MEASUREMENTS

A resistivity survey was conducted in a reclaimed mine spoils disposal site near Wheatland, Indiana to study the ground-water contamination. Due to the high conductivity of the acidic leachate from coal refuse, it was possible to detect the valleys in which this material was dumped (gob valleys) by using the horizontal resistivity profiling technique. The thickness of the gob valleys and information about the stratigraphy of the site were obtained by using the vertical electrical sounding (VES) technique. The VES data for sounding points located near monitoring wells, together with the chemical analyses of water samples taken from these wells, were used to obtain an empirical relationship between the inferred earth resistivity and the amount of Total Dissolved Solids (TDS) in the ground water. The horizontal resistivity profiling data and the VES data at a 30-ft electrode spacing were contoured. The resulting isoresistivity map, together with the empirical relationship, can be used to predict the approximate TDS concentration at a depth of approximately 30 ft at any point on the Wheatland site.
Conspectus as a tool for art libraries in Australia

ABSTRACTMuch of the literature relating to Conspectus discusses its benefits and costs in highly general terms. In this article the author focuses on a small but important segment of the Australian library scene—the art libraries—and concludes that Conspectus is of no particular value to them.
A new model for graduate education and innovation in medical technology.

We describe a new model of graduate education in bioengineering innovation and design- a year long Master’s degree program that educates engineers in the process of healthcare technology innovation for both advanced and low-resource global markets. Students are trained in an iterative “Spiral Innovation” approach that ensures early, staged, and repeated examination of all key elements of a successful medical device. This includes clinical immersion based problem identification and assessment (at Johns Hopkins Medicine and abroad), team based concept and business model development, and project planning based on iterative technical and business plan de-risking. The experiential, project based learning process is closely supported by several core courses in business, design, and engineering. Students in the program work on two team based projects, one focused on addressing healthcare needs in advanced markets and a second focused on low-resource settings. The program recently completed its fourth year of existence, and has graduated 61 students, who have continued on to industry or startups (one half), additional graduate education, or medical school (one third), or our own Global Health Innovation Fellowships. Over the 4 years, the program has sponsored 10 global health teams and 14 domestic/advanced market medtech teams, and launched 5 startups, of which 4 are still active. Projects have attracted over US$2.5M in follow-on awards and grants, that are supporting the continued development of over a dozen projects.
Spatial dark-soliton stripes and grids in self-defocusing materials.

Spatial dark-soliton (SDS) stripes are experimentally found in the transverse plane of a laser beam that passes through a rectilinear diffraction screen before propagating in a self-defocusing nonlinear material. Materials with different mechanisms of nonlinearity manifest the same qualitative results. The SDS nature of the observed phenomenon is verified by numerical simulations of the (2+1)-D nonlinear Schr\"odinger equation, analytical solutions for the (1+1)-D case, and their comparison with experimental data.
Contributions to innate material roughness in resist

A method has been developed to probe the Innate Material Roughness (IMR) of resist materials. We have applied this to EUV and 248 nm resists to deconvolute the material contributions to roughness: 1) the polymer alone, 2) interaction between the polymer, photoacid generator (PAG), base quencher, and photolysis byproducts, 3) the effects of exposure, and 4) development. We studied ESCAP based resists (with more limited data on APEX polymers), an iodonium nonaflate PAG, a tetabutyl ammonium hydroxide (TBAH) base quencher, and standard tetramethylammonium hydroxide (TMAH) development.
Alkaline Hydrolysis of Chloro–N–heterocyclic Reactive Dyes containing Ionisable Amino Groups–I

Various methods for analysing the results obtained in studies of the alkaline hydrolysis of chloro–N–heterocyclic reactive dyes containing ionisable amino groups have been compared and a treatment has been derived whereby the second–order rate constants for hydrolysis of the ionised and un–ionised forms of the dye and the basic dissociation constant of the ionisable amino group can be most easily obtained. This procedure has been applied to some previously published results (I).
Induction of relapsing paralysis in experimental autoimmune encephalomyelitis by bacterial superantigen

THE role of infection in the pathogenesis of clinical relapses that occur in most autoimmune diseases, including multiple sclerosis, remains to be established1,2. Experimental autoimmune encephalomyelitis (EAE) serves as a model for multiple sclerosis, with episodes of relapsing paralysis3–9. In certain strains of mice, T-lym-phocytes expressing the V/β8 T-cell receptor (TCR)6–8 engage the amino-terminal epitope Ac 1–11 of myelin basic protein, leading to EAE. The bacterial superantigen staphylococcal enterotoxin B (SEB) activates V/β8-expressing T cells. Here we show that after immunization with Ac 1–11, or after transfer of encephalitogenic T-cell lines or clones reactive to Acl-11, SEB induces exacerbation or relapses of paralytic disease in mice that are in clinical remission following an initial episode of paralysis, and triggers paralysis in mice with subclinical disease. Tumour necrosis factor has a critical role in the mechanism underlying SEB-induced exacerbation of disease, because anti-tumour necrosis factor antibody given in vivo delays the onset of paralysis triggered by SEB. On reactivation of autoaggressive cells through their T-cell receptor, superantigens may induce clinical relapses of autoimmune disease.
Primary angiosarcoma of the abdominal aorta: a case report and literature review (aortic angiosarcoma)

Fewer than 140 cases of aortic sarcoma have been reported with only 34 classified as angiosarcoma. These rare malignancies most often mimic aortoiliac occlusive or aneurysmal arteriosclerotic disease both clinically and on imaging studies, and the large majority are unexpected and diagnosed pathologically on a surgical specimen or at autopsy [1–5]. A 42-year-old woman who presented with low back pain and claudication was shown by CT and angiography to have infrarenal aortic occlusion. Angiosarcoma was an unexpected pathologic diagnosis based on tissue removed during aortobifemoral bypass surgery. Pre and postoperative CT and angiography are presented along with a review of the literature.
Lanthanide induced NMR perturbations of HEW lysozyme: evidence for nonaxial symmetry.

Abstract Attention has recently been focused on the use of the trivalent lanthanides ions as probes in NMR studies of macromolecules. Previous analyses of the shifts induced by these paramagnetic ions have assumed that the magnetic susceptibility tensor of the metals is axially symmetric. This study has tested the validity of this assumption by analyzing reported NMR shift and relaxation data for various lanthanide complexes with lysozyme. For the Gd 3+ -lysozyme complex the broadening data, fit to a ( 1 r 6 ) model, places the metal ion in close proximity to the reported x-ray position. Contrary to current assumptions, the shifts induced by Nd 3+ and Ce 3+ exhibit considerable non-axial character. On the basis of a statistical hypothesis test, the axially symmetric model was rejected with more than 97% confidence.
Prognostic parameters in localised melanoma: Gender versus anatomical location

Extremity location and female gender are both considered favourable prognostic parameters in primary melanoma, but since they cluster in the same group of patients, the question remains as to whether they are both independent variables. Multivariate analysis of 695 patients with primary, localised melanoma was used. The effects of gender and anatomical location were compared directly by sequentially controlling one factor while the other remained free. Following multivariate analysis, significant prognostic factors related to survival were the thickness of the primary lesion (P < 0.0001), the age of the patient at diagnosis (P < 0.0001), the gender of the patient (P = 0.0008) and the anatomical location of the primary lesion (P = 0.005). Thicker lesions, patients older than 50 years, males, and trunk, head and neck locations had poorer prognoses. There was a significant difference in survival according to gender within each location, extremity (P = 0.002) or trunk, head and neck (P = 0.0004); however, there was no significant difference in survival according to anatomical location within each gender, male (P = 0.11) or female (P = 0.29). The thickness of the primary lesion, the age of the patient at diagnosis, the gender and the anatomical location of the melanoma are all significant prognostic parameters in localised melanoma. Gender appears to have a more pronounced effect on survival than anatomical location.
ThermoMouse: An In Vivo Model to Identify Modulators of UCP1 Expression in Brown Adipose Tissue

Obesity develops when energy intake chronically exceeds energy expenditure. Because brown adipose tissue (BAT) dissipates energy in the form of heat, increasing energy expenditure by augmenting BAT-mediated thermogenesis may represent an approach to counter obesity and its complications. The ability of BAT to dissipate energy is dependent on expression of mitochondrial uncoupling protein 1 (UCP1). To facilitate the identification of pharmacological modulators of BAT UCP1 levels, which may have potential as antiobesity medications, we developed a transgenic model in which luciferase activity faithfully mimics endogenous UCP1 expression and its response to physiologic stimuli. Phenotypic screening of a library using cells derived from this model yielded a small molecule that increases UCP1 expression in brown fat cells and mice. Upon adrenergic stimulation, compound-treated mice showed increased energy expenditure. These tools offer an opportunity to identify pharmacologic modulators of UCP1 expression and uncover regulatory pathways that impact BAT-mediated thermogenesis.
Wanted: an Argus-like dentist

The Frenchman has a saying: Autre temps, autre moeurs, other times, other customs. With a shrug of the shoulders he accepts the inevitability of today’s devel­ opments and tomorrow’s discoveries. O f course, there is another Frenchman lurk­ ing in the background and with a wink, he replies: Plus ca change, plus c’est la meme chose, the more it changes, the more it remains the same. One may say that dental practitioners align themselves behind one or another of these two pro­ verbial figures. There are those who believe that the emergence of the basic sciences as an in­ tegral part of the practice of modem den­ tistry is slowly altering the position which the dentist occupies on the “health service team.” On the other hand, too many re­ fuse to recognize this changing concept and are satisfied to relegate their efforts to the mere technical aspects of dental care. Thus the timeworn image of the dentist being equated with the man who fills cavities and pulls teeth is perpetu­ ated. The inescapable truth is that every dentist must today be an Argus as well. Like Argus, the hundred-eyed guardian of Io, the modem dentist must be on constant guard for signs his predecessor never worried about, perhaps never even knew of. It can hardly be denied that a slow revolution in dental care is gathering momentum as a result of three factors:
Aggressive bladder carcinoma in an HIV-positive man with tetraplegia and neurogenic bladder

AbstractBackground/objectivePatients with neurogenic bladder secondary to spinal cord injury who are managed long term with an indwelling catheter are known to be at increased risk for transitional cell carcinoma of the bladder. Immunosuppression is a known risk factor for malignancies that often are more aggressive than those seen in normal populations.MethodCase report and discussion of management recommendations.ResultsWe summarize the case of a 44-year-old HIV-positive C5–C6 incomplete tetraplegic male (date of injury 1980), who was diagnosed with transitional cell carcinoma of the bladder and succumbed to disease within 6 months of diagnosis. The patient was a non-smoker who was never managed with an indwelling catheter. There has been no such case reported in the literature.ConclusionsHIV infection in the presence of a neurogenic bladder may carry an increased risk of aggressive bladder malignancy. More studies are warranted to determine whether routine annual screening with cystoscopy in all patien...
Tunneling and sensing effects of high quality InN nanowires

High quality InN nanowires (NWs) grown by chemical vapor deposition (CVD) has been investigated for sensing applications. The NWs were synthesized using a novel approach that enhanced the cracking of NH3 precursor and dramatically improving the growth rate and material quality. These InN NWs based field effect transistors (FETs) showed excellent gate control and were highly sensitive to variety of gaseous and vapor phase analytes, including acetone and water vapors. With very high carrier density (>1019 cm-3), and narrow diameter (even <;10 nm), these InN NWs demonstrate to be suitable for highly sensitive and selective gaseous detection based on the field emission method, with specific and low turn-on voltage.
Response uncertainty and imitation: The interactive effects of age and task options

Abstract It was reasoned that younger children would be more susceptible to situational uncertainty and thereby imitate more than older children or peers of the same age tested under more structured conditions. Children 6- through 8- and 12- through 14-years-old observed a model toss a bean bag at a target and were tested for target relevant and incidental imitation under conditions of two task options (high structure) or 10 task options (low structure). On both measures of imitation, preadolescents in the low structure condition imitated significantly more than adolescents. Preadolescents also imitated more incidental behavior in the low than in the high structure condition. Additionally, it was found that personality variables predicted imitative behavior of younger subjects in the low structure condition only.
Potentially modifiable factors associated with disability among people with diabetes.

Objective: This article seeks to identify potentially modifiable factors associated with disability among people with diabetes. Study Design and Setting: Among people with diabetes (N = 4357) in a large health maintenance organization, disease severity, psychologic and behavioral risk factors for disability were assessed. Disability was evaluated by the WHO Disability Assessment Scale (WHO-DAS-II), the SF-36 Social Functioning scale, and days of reduced household work. Results: Depression was associated with a tenfold increase in elevated WHO-DAS-II and low SF-36 Social Functioning scores, and a fourfold increase in 20+ days of reduced household work. Minor depression and the presence of three or more diabetic complications were associated with approximately a twofold increase in disability risk. Diabetic symptoms, chronic disease comorbidity, and reduced exercise were also associated with disability. Conclusion: Among people with diabetes, depression, diabetic complications, and exercise are potentially modifiable factors associated with disability. This suggests that integrated, biopsychosocial approaches may be needed to understand and to ameliorate disability among people with diabetes.
Fulminant Hepatic Failure Secondary to Primary Hepatic Angiosarcoma

Background. Hepatic angiosarcoma is a rare and aggressive tumor that often presents at an advanced stage with nonspecific symptoms. Objective. To report a case of primary hepatic angiosarcoma in an otherwise healthy man with normal liver function tests two months prior to presenting with a short period of jaundice that progressed to fulminant hepatic failure. Methods. Case report and review of literature. Conclusion. This case illustrates the rapidity of progression to death after the onset of symptoms in a patient with hepatic angiosarcoma. Research on early diagnostic strategies and newer therapies are needed to improve prognosis in this rare and poorly understood malignancy with limited treatment options.
Generation of 300 ps laser pulse with 1.2 J energy at 532 nm by stimulated Brillouin scattering in water

We experimentally demonstrate SBS pulse compression in water from 10 ns, 2.3 J to 300 ps, 1.2 J. To our best knowledge, this is the highest compressible energy that has been achieved at 532 nm.
Tea consumption and epithelial ovarian cancer risk: a systematic review of observational studies.

Ovarian cancer is the seventh most common type of cancer in the United States and is often not diagnosed until late stages. Thus, identifying potential risk factors and prevention strategies is particularly important. This systematic review analyzes existing evidence on the association between tea consumption and epithelial ovarian cancer risk in human observational studies. PubMed was searched through September 30, 2010 for eligible articles; 16 articles met the inclusion criteria for this systematic review. Five studies found overall tea intake to be associated with a decreased epithelial ovarian cancer risk, 1 found a borderline decreased risk, 9 found no association, and 1 found a borderline increased risk. Overall, it does not appear that tea consumption increases risk of ovarian cancer, but there is insufficient evidence at this point to conclude that it is protective against ovarian cancer. Many of the studies included in this review had important limitations, especially related to the lack of deta...
Backpac: a parallel goal-driven reasoning system

Abstract To handle complex problems of the type solved by human experts, knowledge bases will need to become larger than 10,000 chunks of knowledge. In order to provide necessary response times it appears that parallel inference must be considered. The advent of affordable parallel processing computers may allow the use of parallel inference to decrease reasoning time. In this paper we discuss Backpac, a backward-chained inferencing system designed to run on parallel processor machines. The system has been developed in Multilisp and rewritten in mul-t . The system has been tested on a 10 processor Encore Multimax in both languages. Several experiments, in Multilisp, have been run on the Concert [22] multiprocessor at the Harris Corporation. The speedups have ranged as high as an order of magnitude.
Evidence of an EGF/TGF‐α—independent pathway for estrogen‐regulated cell proliferation

To elucidate the relationship between epidermal growth factor (EGF)/transforming growth factor (TGF-α) and estradiol-17β (E) in cell proliferation, we examined their effects on the breast cancer cell line, CAMA-1. While E was able to consistently induce cell proliferation under a variety of experimental conditions, EGF/TGF-α was without effect. Despite the presence of the receptor (EGFR) gene, mature EGFR protein and mRNA were not detected by radioreceptor assay, 35S Met-labelling, and the Intron Differential RNA/PCR method under conditions in which cells remain responsive to E. Furthermore, TGF-α is not an autocrine factor in CAMA-1 cells. We demonstrated unequivocally that EGF/TGF-α interaction with EGFR is not an obligatory event in mediating estrogen-stimulated cell proliferation.
Targeted drug delivery to C6 glioma by transferrin-coupled liposomes.

Recent advances in liposome technology have shown promise relative to the introduction of chemotherapeutic agents with reduced toxicity, extended longevity, and potential for cell-specific targeting. In this study we report the engineering of a liposomal delivery system for the chemotherapeutic drug doxorubicin. The system was targeted specifically to C6 glioma in vitro by coupling transferrin to the distal ends of liposomal polyethylene glycol (PEG) chains. The transferrin receptor is overexpressed on glioma, with the extent of overexpression correlated to the severity of the tumor. Significantly increased gliomal doxorubicin uptake was achieved by drug encapsulation within transferrin-coupled liposomes compared to other liposome populations. Doxorubicin encapsulated within transferrin-coupled liposomes exhibited 70% of free doxorubicin uptake as compared to 54, 14, and 34% for non-PEG, PEG, and albumin-coupled PEG liposomes, respectively. Competitive binding assays support the receptor-mediated mechanism of targeting. The addition of one μM free transferrin reduced the uptake of doxorubicin encapsulated within transferrin-coupled liposomes by 30%. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res, 51, 10–14, 2000.
The electronic structure of gold overlayers on Cu(001)

Gold was evaporated onto a Cu(001) surface at room temperature and studied with angle resolved photoelectron spectroscopy, using synchrotron radiation as the excitation, as well as low energy electron diffraction and Auger electron spectroscopy. Measurements include the probing of the dependencies of valence band binding energies upon coverage and photon energy. At a Au coverage of 12 monolayers, the spectra and valence band dispersion relations (using hv=8−32 eV) of the surface were found to be very similar to those of bulk Au(111). The valence band spectra, collected using hv=110 eV radiation, confirm that assessment. At coverages from one to six monolayers, the valence band structure was observed to undergo significant changes with coverage. A feature corresponding to the Au(111) surface state was prominent at coverages of two or more monolayers.
Transmission side protection performance with Type-IV wind turbine system integration

The converter controls of the full-converter based Type-IV wind turbine system (WTS) limits the fault current contribution to about 1.1–1.2 per unit (pu). Further, these fault currents are balanced even for unbalanced faults. The absence of significant fault current magnitudes and the lack of negative and zero sequence components in the fault currents poses challenges to the protection of power systems that interconnect wind turbines. This paper first presents the design of the controls of the grid-side voltage sourced converter (VSC) with an averaged non-switching model and a transmission interconnection through a step-up transformer. Faults are placed on the transmission system and fault currents and voltages are measured at relay location and converted to COMTRADE format. These are played back to a simulated relay to analyze the performance of distance elements and the protection elements that supervise them when the fault current is supplied by the grid side converter.
Marginal Fracture of Amalgam Restorations

Marginal fracture characteristics of clinical restorations made from three amalgam alloys were evaluated during a four-year period. Marginal fracture increased with age; the rate of increase was different among alloys, and the ranking of alloys remained the same during the four years.
Functional characterization of the H-2Dp gene product.

A λ clone containing the Dp gene was used to transform L cells. The Dp product expressed was identified by two-dimensional gel electrophoreis and flow cytometry. The Dp product expressed by the L cells was recognized by DP-specific flow cytometry. The Dp product expressed by the L cells was recognized by Dp-specific but not Kp-specific killer T cells. This killing was inhibited by monoclonal antibodies specific for Dp but not Kp or Kk antigens. Similarly, lymphocytic choriomeningitis virus (LCMV) killer T cells from B 10.P mice were able to kill LCMV-infected L12a cells, but not LCMV-infected Ltk+. Again only Dp monoclonal antibodies could inhibit this killing.
Evaluation Of The Contrast Ratio Of Intensified Fluoroscopic Imaging Systems

Large area contrast loss in image intensifiers results in reduced performance at low spatial frequencies and may limit the imaging capabilities of such systems for structures of clinical interest having inherently low subject contrast. The contrast ratio of image intensifiers is a measure of large area contrast loss which may be evaluated under laboratory conditions by photometric techniques. Unfortunately such techniques are not readily extended to clinically installed systems. A technique for the measurement of contrast ratio on clinically installed systems, incorporating a film recording camera, is proposed which eliminates the requirement of having a precise knowledge of the film's characteristic curve. The results of measurements obtained with this technique on clinical systems, as well as comparison of this technique to photometric measurements under laboratory conditions are presented, along with a discussion of the associate problems and pitfalls.
The Pathophysiology of Concussions in Youth

Mild traumatic brain injury, especially sport-related concussion, is common among young persons. Consequences of transient pathophysiologic dysfunction must be considered in the context of a developing or immature brain, as must the potential for an accumulation of damage with repeated exposure. This review summarizes the underlying neurometabolic cascade of concussion, with emphasis on the young brain in terms of acute pathophysiology, vulnerability, alterations in plasticity and activation, axonal injury, and cumulative risk from chronic, repetitive damage, and discusses their implications in the context of clinical care for the concussed youth, highlighting areas for future investigation. Language: en
Design strategies for a computer-based instruction system

In February, 1984, the Computer Science Department at Brigham Young University began working on a project that would automate the delivery of a beginning programming class. This project known as THE ELROND PROJECT, was funded by the university with the expectation that the instructional delivery costs and the need for additional faculty for this course could be reduced.This paper describes the system design and principles that were used and presents strategies for creating computer automated courseware.
An enthusiast's guide to agrostology

Abstract Population Biology of Grasses edited by G.P. Cheplick Cambridge University Press, 1998. £50.00/$85.00 hbk (xii +399 pages) ISBN 0 521 57205 3
A MODEL FOR INTERVAL‐CENSORED TUBERCULOSIS OUTBREAK DATA

As the incidence of tuberculosis (TB) has increased in the United States, occupationally acquired TB has increased among the health care workers (HCWs). This paper describes a model developed in response to the needs of an outbreak of multidrug-resistant TB. One of the goals of the outbreak investigation was to estimate the risk of tuberculin skin test (TST) conversion as a function of HCW job type and the period during which persons were employed over the study period. TST conversions were evaluated at periodic examinations and data are interval-censored. We present a generalized linear model that extends Efron's survival model for censored survival data to the case of interval-censored data.
Densification of uranium dioxide fuel pellets prepared by spark plasma sintering (SPS)

Abstract An investigation into the influence of processing parameters on densification of UO2 powder during spark plasma sintering (SPS) is presented. A broad range of sintering temperatures, hold time and heating rates have been systematically varied to investigate their influence on the sintered pellet densification process, grain growth, hardness, and Young’s modulus. The results revealed that up to 96% theoretical density (TD) pellets can be obtained at a sintering temperature of 1050 °C for 30 s hold time and a total run time of only 10 min. The resulting UO2 pellets had an average Vickers hardness of 6.4 ± 0.4 GPa and Young’s modulus of 204 ± 18 GPa, which are in excellent agreement with values reported in literature for UO2 processed by other methods.
The chemical composition and porosity of refractories as factors in their wettability with carbon steel

In an argon atmosphere the wetting angle of aluminosilicate specimens with Steel 35 at 1550°C depends on the phase composition of the specimen, i.e., with a corundum content of 1–7% the wetting angle increases with the percent mullite in the specimen.
Extending the behavioral capabilities of the object-oriented paradigm with an active model of propagation

Object-oriented design techniques have begun to play a critical role in increasing productivity, assuring correctness, and modeling both the structure and behavior of applications. However, while most object-oriented models support intra-class behavior definition through encapsulation, inter-class relationships and behavior are supported in only a limited sense, i.e., within ISA or inheritance hierarchies. This is a serious draw-back when attempting to model advanced applications such as software-development environments (SDEs) and CAD/CAM. In order to model these critical inter-class relationships and behavior, our goal is to incorporate propagation actions into an object-oriented data model at the design-phase level. This results in increased accuracy in the modeling of information, more complete specification of system behavior, elimination of some side effects, and decreased application coding errors. To meet this goal, this paper presents the active model of propagation (AMP) which supports the specification of inter-class relationships during the design phase to permit system enforced propagation.
B12 Coenzyme Content of the Nodules from Legumes, Alder and of Rhizobium meliloti

IT has been established1 that cobalt is an essential element for the symbiotic growth of soybean plants and Rhizobium japonicum in a purified solution lacking-combined nitrogen. It has been shown also that cobalt is needed for alfalfa inoculated with Rhizobium meliloti2. Legumes supplied with adequate fixed nitrogen do not respond to additions of cobalt1,2; but R. japonicum, R. meliloti, R. leguminosarum, R. trifolii, and R. phaseoli cultured in a purified medium containing both ammonium and nitrate nitrogen failed to grow normally without cobalt3,4. The vitamin B12 content of root nodules from soybean plants is positively correlated with the cobalt supply in the nutrient medium1, suggesting that an important role of this element in nodule metabolism is related to that of the vitamin.
The Labor Supply of Female Heads of Household: Comparisons With Male Heads and Wives*

This paper compares a model of labor supply for female heads of household, male heads, and wives. Not only have female-headed households increased significantly as a proportion of all households in recent years, but these households are also more likely to be in poverty than are other households. Yet, the determinants of labor supply for this increasingly important demographic group still are largely unknown. Analyses are performed on a sample of employed female and male heads and wives from the 1976 Survey of Income and Education. We examine the effects of wages, unearned income, number of children, and several other variables on hours worked per year, allowing for race interactions. We find that female heads and wives are similar in the effects of wages on their labor supply, while female and male heads are similar in the positive effect of children. We conclude that although financial need, as evidenced by low wages and children, increases female heads’labor supply, employment in more advantaged, non-female dominated jobs and core industries is needed to promote their full participation in the labor force.
Exponentially-convergent strategies for defeating the Runge Phenomenon for the approximation of non-periodic functions, part two: Multi-interval polynomial schemes and multidomain Chebyshev interpolation

Approximating a smooth function from its values f(x"i) at a set of evenly spaced points x"i through P-point polynomial interpolation often fails because of divergence near the endpoints, the ''Runge Phenomenon''. This report shows how to achieve an error that decreases exponentially fast with P by means of polynomial interpolation on N"s subdomains where N"s increases with P. We rigorously prove that in the limit both N"s and M, the degree on each subdomain, increase simultaneously, the approximation error converges proportionally to exp(-constantPlog(P)). Thus, division into ever-shrinking, ever-more-numerous subdomains is guaranteed to defeat the Runge Phenomenon in infinite precision arithmetic. (Numerical ill-conditioning is also discussed, but is not a great difficulty in practice, though not insignificant in theory.) Although a Chebyshev grid on each subdomain is well known to be immune to the Runge Phenomenon, it is still interesting, and the same methodology can be applied as to a uniform grid. When a Chebyshev grid is used on each subdomain, there are two regimes. If c is the distance from the middle of the interval [-1,1] to the nearest singularity of f(x) in the complex plane, then when cN"s@?1, the error is proportional to exp(-cP), independent of the number of subdomains. When cN"s@?1, the rate of convergence slows to exp(-constantPlog(P)), the same as for equispaced interpolation. However, the Chebyshev multidomain error is always smaller than the equispaced multidomain error.
Total Synthesis of the Epoxy Isoprostane Phospholipids PEIPC and PECPC

A total synthesis of the naturally occurring hydroxy ketone PEIPC 1, a compound that plays a role in endothelial activation in atherosclerosis, has been completed via a triply convergent preparation of a protected EI derivative 13 from 3,5-diacetoxycyclopentene 7, pentane-1,5-diol, and vinyllithium, using Sharpless epoxidation and enzymatic resolution as key steps. Final coupling with lyso-PC 16 and silyl group deprotection gave PECPC 2 and PEIPC 1, which showed the same activity as natural PECPC and PEIPC. [reaction: see text]
Effects of the ability to locomote on infants' social and exploratory behaviors: An experimental study.

Two experiments were conducted to test effects of infants' ability to locomote on their social and exploratory behaviors. Participants in the first study were 20 normal infants between the ages of 6V2 and 10 months. None of these infants was able to locomote independently. Each was observed, in a standard laboratory environment, for 10 min in an infant "walker" and for 10 min out of the walker. The second study compared effects of walker-assisted locomotion with effects of independent locomotion. Participants were 16 additional infants, all able to creep or crawl. Age parameters were closely similar to those of the first sample Taken altogether, the results indicated that the two modes of locomotion, walker-assisted or independent, afforded similar experiences within a standard environment, but experiences quite different from those of the nonlocomoting infant Some behaviors actually emerged as a function of the ability to locomote, others changed in frequency; still others were extended to new features of the environment In addition, all classes of behaviors measured were known from other studies to affect adults' behavior toward infants. Therefore, changes in these behaviors should lead to changes in infants' social experiences. The systematic reorganization of experiences, both social and nonsocial, as a result of locomotion has implications for social development, and for perceptual, cognitive, and language development as well. Language: en
Research on audio-tutorial instruction: A meta-analysis of comparative studies

The present article describes a statistical synthesis of results from 48 comparative studies of an innovative method of college teaching, Postlethwait's Audio-Tutorial or A-T approach. The analysis showed that in general A-T instruction has a significant but small overall effect on student achievement in college courses, and it has no significant effect on student course evaluations or on course completions. Findings were similar for well-designed and less-well-designed studies included in this analysis, and they were also similar for studies carried out at different types of schools and in different subject areas. Results reported in journals, however, were more favorable to A-T than results found in dissertations and other unpublished reports.
Acetone, Isopropanol, and Butanol Production by Clostridium beijerinckii (syn. Clostridium butylicum) and Clostridium aurantibutyricum

Thirty-four strains representing 15 species of anaerobic bacteria were screened for acetone, isopropanol, and n-butanol (solvent) production. Under our culture conditions, several strains of Clostridium beijerinckii and C. aurantibutyricum produced at least 40 mM n-butanol (C. acetobutylicum strains produced up to 41 mM n-butanol under similar conditions). Both solvent-producing and non-solvent-producing strains of C. beijerinckii have high DNA homology with a reference strain of C. beijerinckii. Strains labeled "Clostridium butylicum" are phenotypically similar to C. beijerinckii and showed at least 78% DNA homology to a reference strain of C. beijerinckii. Therefore, these "C. butylicum" strains are members of C. beijerinckii. An earlier DNA homology study has shown that C. beijerinckii, C. aurantibutyricum, and C. acetobutylicum are distinct species.
Optimal use of Myco/F lytic and standard BACTEC blood culture bottles for detection of yeast and mycobacteria.

Abstract Context.—The optimal use of dedicated fungal and mycobacterial blood culture bottles, such as the BACTEC Myco/F Lytic bottle, has not been well defined in clinical practice. Objectives.—To compare the performance of Myco/F Lytic and standard blood culture in clinical practice in an urban tertiary care hospital setting and to implement a strategy for optimal use of Myco/F Lytic culture. Data Sources.—Retrospective review of laboratory records. Results.—Myco/F Lytic culture did not increase detection of yeasts. Nor did it decrease time to detection except for Candida glabrata, where mean time to positivity dropped from 2.6 ± 1.1 days in standard to 1.8 ± 0.8 days in Myco/F Lytic culture. Therefore, an algorithm was developed in which Myco/F Lytic culture was reserved primarily for detection of mycobacteria in patients with severely depressed CD4 counts. Implementation of this algorithm led to a sustained 3-fold reduction in Myco/F Lytic blood culture usage. Conclusions.—Retrospective analysis sugge...
THIS IS MY BABY: FOSTER PARENTS’ FEELINGS OF COMMITMENT AND DISPLAYS OF DELIGHT

This study examined the association between foster parents' commitment to their young foster children and the delight they showed in their interactions with children. Seventy foster parent-child dyads were included as participants. The dyads were videotaped during a play interaction when children were between 9 and 28 months, with delight coded on the basis of foster parents' responses to children. Caregivers were interviewed with the "This Is My Baby" Interview (B. Bates & M. Dozier, 1998), with commitment coded as the extent to which parents expressed interest in enduring relationships with their foster children and the extent to which they thought of them as their own. Regression analyses revealed that commitment was a significant predictor of foster parent delight. Foster parents who were more highly committed to their foster children showed greater delight in their children than did foster parents who were less highly committed. These results suggest an important way in which caregiver commitment is transmitted to foster children.
Absolute OH Number Density Measurements in Lean Fuel-Air Mixtures Excited by a Repetitively Pulsed Nanosecond Discharge

OH Laser Induced Fluorescence (LIF) is used for temperature and absolute OH number density measurements in an atmospheric pressure, near stoichiometric CH4-air flame generated by a Hencken burner. OH rotational temperature is inferred with excitation scans of both the OH A-X (0,0) and (1,0) bands. OH LIF signal is corrected by considering transition-dependent total radiative decay rate, laser attenuation, and fluorescence trapping. The relative OH concentrations are put on an absolute scale by calibrating the optical collection constant using Rayleigh scattering. The measured absolute OH number density in the flame is compared with laser absorption measurements done at the same locations, showing good agreement and thus demonstrating the efficacy of our calibration approach employing Rayleigh scattering—for a low temperature and pressure, lean, fuel-air mixtures excited by a repetitively pulsed nanosecond (nsec) discharge. Here, a premixed fuel-air flow, initially at T0=500 K and P=100 torr, is excited by the discharge in a plane-to-plane geometry, operated in burst mode at 10 kHz pulse repetition rate. Burst duration is limited to 50 pulses, to preclude plasma-assisted ignition. The discharge uniformity in air and fuel-air flows is verified using sub-nsec-gated images, employing an intensified charge-coupled device camera. Time-resolved, absolute OH number density, measured after the discharge burst, demonstrates that OH concentration in C2H4-air, C3H8-air, and CH4 is highest in the leanest mixtures, while in H2-air, OH concentration is nearly independent of the equivalence ratio. In C2H4-air and C3H8-air, unlike in CH4-air and in H2-air, transient OH-concentration overshoot after the discharge is detected. In C2H4-air and C3H8-air, OH decays after the discharge on the time scale of ~0.02-0.1 msec, suggesting little accumulation during the burst of pulses repeated at 10 kHz. In CH4-air and H2-air, OH concentration decays within ~0.1-1.0 msec and 0.5-1.0 msec, respectively, showing that it may accumulate during the burst. The experimental results are compared with kinetic modeling calculations using plasma / fuel chemistry model employing several H2-air and hydrocarbon-air chemistry mechanisms. Kinetic mechanisms for H2-air, CH4-air, and C2H4-air developed by A. Konnov provide the best overall agreement with OH measurements. In C3H8-air, none of the hydrocarbon chemistry mechanisms agrees well with the data. The results show the need for development of an accurate, predictive low-temperature plasma chemistry / fuel chemistry kinetic model applicable to fuels C3 and higher.
Nonlinear dynamics of uni-cyclic pursuit

We propose a smooth uni-cyclic pursuit control law in order to avoid controller discontinuity. The local stability of all the equilibria are characterized. Global bifurcation analysis of three different cases are carried out based on phase portraits of a 2-dimensional system. Numerics agree well with the theoretical results.