cssi/SciSciGPT-SciSciNet huggingface dataset:
Joint Estimation of Trajectory and Model Parameters for Single Particle Tracking of 3D Confined Diffusion Using the Double-Helix Point Spread Function

Abstract Single particle tracking plays a significant role in biophysics through its ability to reveal dynamic mechanisms and physical properties of biological macromolecules inside living cells. The motion of these molecules can often be modeled as a confined diffusion. The standard paradigm in the biophysics community is to first estimate the trajectory of a particle and then use a technique such as the Mean Square Displacement or the Maximum Likelihood Estimation (MLE) to determine model parameters. These approaches, however, ignore the fact that localization and parameter estimation problems are coupled. We have previously introduced a framework based on optimal estimation theory to simultaneously do localization and parameter estimation. Here we build upon that work by expanding it to include a recent advance in imaging three dimensional motion, namely the Double-Helix (DH) engineered Point Spread Function (PSF). The DH-PSF encodes the axial position of the particle directly into the 2D image acquired by the camera mounted to the microscope. Our approach uses Expectation Maximization (EM) and Sequential Monte Carlo (SMC) to handle the nonlinearities in the observation and motion models. In this paper, we also improve upon the computational complexity of this scheme, using a Gaussian Particle Filter and Backward Simulation Particle Smoother in the SMC elements of the algorithm. We compare our scheme through simulation to state of the art methods based on localization using Gaussian fitting followed by MLE of the model parameters. These results show that our method outperforms GF-MLE at the low signal intensity levels common to biophysical experiments.
Parkes-Weber syndrome in the emergency department

This case report describes a 20-year-old woman presenting to the emergency department (ED) with unilateral leg swelling. After multiple visits to the ED and workups with rheumatology, dermatology, interventional radiology and genetics, she was finally diagnosed with Parkes-Weber syndrome. The purpose of this case report is to illustrate the common and uncommon presentations, mimickers and work-up of Parkes-Weber syndrome as well as provide a brief overview of vascular malformations in general.
A Critique of the Obama Preschool Proposal

President Obama has proposed "Preschool for All" with a pledge of $75 million to the states to implement "high quality" full-time preschool programs for low-income children as part of the regular K-12 system. The states would come up with additional funds to provide for the remaining higher income students. This proposal comes despite the fact that rigorous evaluations of the existing federal pre-K program, Head Start, show no lasting effects. Presumably, Head Start does not have sufficient quality, at least as compared to "high quality" programs implemented by several states and school districts such as New Jersey, Oklahoma, and Boston. This paper reviews existing research on Head Start and these selected "high quality" programs. It finds that the quality of Head Start programs is actually higher than the New Jersey program, and moreover there is little evidence that common measures of quality are strongly related to preschool outcomes. This makes sense when one considers that pre-K children are only 3 or 4 years old, and the necessary subject matters can be mastered by instructors without formal college degrees. It also finds that most of the evaluations of high-quality pre-K programs use a research design that is susceptible to serious bias due to program dropouts. The paper recommends that a small portion of Head Start funds be used to develop a thorough and rigorous demonstration and evaluation of "high quality" preschool programs before spending billions of dollars on another untested educational program.
Chapter 4 The Insect Nervous System as a Model System for the Study of Neuronal Death

Publisher Summary This chapter discusses neuronal death in insects, although examples from other invertebrates are presented to illustrate or support particular points. Because most of the insect work has been done on the regulation of neuronal degeneration during postembryonic stages of the moth, Manduca sexta, the major proportion of the chapter discusses this insect. The ability to follow the degeneration process in identified motoneurons has allowed a precise description of the events associated with cell death. In Manduca, this is a highly ordered process with cells dying according to a precise temporal sequence. The removal of the trophic support provided by a steroid hormone is an important factor in causing death, but an analysis of the temporal pattern of degeneration suggests that trophic interactions among cells may also be important. The possibility that the activation of new genes is involved in programmed cell death is a recurrent theme in many invertebrate systems. The studies on C. elegans clearly show that the activation of new genetic information is necessary if death is to occur. The ribonucleic acid (RNA) inhibitor studies in Manduca are also consistent with such hypotheses for neuronal death in insects.
The Influence of Government on Human Factors Research and Development

In order to examine the interrelationships among participants in the Human Factors (HF) Research and Development (R&D) process, questionnaires soliciting information about research practices were sent to contractors, government laboratory managers and HF practitioners in industry. Although a majority of respondents appear to be satisfied with the way in which HF research is conducted, a sizeable minority have serious reservations about that process.
Characterization of the acclimation period before anaerobic dehalogenation of halobenzoates

The acclimation periods prior to detectable dehalogenation of halogenated benzoates in anaerobic lake sediments ranged from 3 weeks to 6 months. These acclimation periods were reproducible over time and among sampling sites and were characteristic of the chemical tested. The lengthy acclimation period appears to represent an induction phase in which little or no aryl dehalogenation is observed, followed by an exponential increase in activity typical of an enrichment response. Continuous growth from the time of the first exposure to the chemical is inconsistent with the extremely low per-cell activities estimated for the early days of the acclimation period and the fact that the dehalogenation yields no carbon to support microbial growth. The finding of a characteristic acclimation time for each chemical argues against nutritional deficiency, inhibition, or predation as an explanation for this phase of metabolism, while the reproducibility of the findings with time and space and among replicates argues against genetic changes as the explanation. The acclimation times did correlate with the eventual dehalogenation rates. This may reflect the general energy limitations in the anaerobic communities and suggests that those chemicals with faster dehalogenation rates provide more energy for the induction and growth phases of the active population.
Optimization of preventive maintenance scheduling in processing plants

Abstract A new methodology designed to optimize both the planning of preventive maintenance and the amount of resources needed to perform maintenance in a process plant is presented. The methodology is based on the use of a Montecarlo simulation to evaluate the expected cost of maintenance as well as the expected economic loss, an economical indicator for maintenance performance. The Montecarlo simulation describes different failure modes of equipment and uses the prioritization of maintenance supplied, the availability of labour and spare parts. A Genetic algorithm is used for optimisation. The well-known Tennessee Eastman Plant problem is used to illustrate the results.
DHT routing using social links

The equality and anonymity of peer-to-peer networks makes them vulnerable to routing denial of service attacks from misbehaving nodes. In this paper, we investigate how existing social networks can benefit P2P networks by leveraging the inherent trust associated with social links. We present a trust model that lets us compare routing algorithms for P2P networks overlaying social networks. We propose SPROUT, a DHT routing algorithm that significantly increases the probability of successful routing by using social links. Finally, we discuss further optimization and design choices for both the model and the routing algorithm.
Mutational analysis of a Ser/Thr phosphatase. Identification of residues important in phosphoesterase substrate binding and catalysis.

The Ser/Thr phosphoprotein phosphatases (PPases) display similarities in amino acid sequence and biochemical properties. Most members of this family require transition metal ions for activity. The smallest family member, the bacteriophage lambda PPase (lambda-PPase), has been successfully overexpressed in Escherichia coli, purified, and characterized (Zhuo, S., Clemens, J.C., Hakes, D.J., Barford, D., and Dixon, J. E. (1993) J. Biol. Chem. 268, 17754-17761). Site-directed mutagenesis has now been employed to define amino acid residues in lambda-PPase required for metal ion binding and catalysis. Conservative amino acid substitutions at residues Asp20, His22, Asp49, His76, and Glu77 affected lambda-PPase catalysis and metal ion binding, whereas substitutions at residues Arg53 and Arg73 affected catalysis and substrate binding. Each of these residues is invariant in all phosphoprotein phosphatases, suggesting that these residues may play important roles in binding and catalysis in all of the PPases. Computer-assisted sequence alignment further revealed that lambda-PPase residues Asp20, His22, Asp49, His76, Arg53, and Arg73 lie within three larger regions of PPase sequence identity with the consensus sequence (DXH-(approximately 25)-GDXXD-(approximately 25)-GNHD/E). This motif can be found in a wide variety of phosphoesterases unrelated to the PPases and defines structural and catalytic features utilized by a diverse group of enzymes for the hydrolysis of phosphate esters.
Physical activity, sedentary behaviors, physical fitness, and their relation to health outcomes in youth with type 1 and type 2 diabetes:A review of the epidemiologic literature

Abstract Diabetes is a leading chronic disease of childhood and adolescence. In addition to the well-known auto-immune, insulin-dependent diabetes mellitus (type 1 diabetes (T1D)), the past two decades have witnessed the emergence of type 2 diabetes (T2D) in children and adolescents, which previously was only seen in middle-aged or older adults. One of the key components of diabetes management is physical activity (PA). The beneficial effects of increased PA and decreased sedentary behavior are extremely important in youth with diabetes because of the markedly increased long-term risk of cardiovascular disease in this population compared to persons without diabetes. This review aims to comprehensively summarize the epidemiologic, observational research published and listed in PubMed between 1970 and 2012 on PA and sedentary behaviors, as well as physical fitness in children and adolescents with T1D and T2D. Additionally, we describe briefly the state of knowledge on perceived barriers of PA in persons with diabetes, with a focus on hypoglycemia. Finally, we provide an overview of the epidemiological literature pertaining to health benefits of increased PA in youth with T1D and T2D and briefly discuss the topic of exercise-related hypoglycemia.
Micropuncture localization of kallikrein secretion in the rat nephron.

Micropuncture localization of kallikrein secretion in the rat nephron. We have used free–flow micropuncture to study the tubular locus at which kallikrein enters the urine. Kallikrein was measured by a newly developed, very sensitive assay for kininogenase activity; active kallikrein was measured directly by this assay and total kallikrein after activation of inactive kallikrein. Kallikrein was readily detected in all of 17, late distal tubular fluid–samples. In contrast, kallikrein was too low to detect in 15 of 17 proximal or in 11 of 14 early distal tubular fluid samples. Calculations indicate that less than 10% of urinary kallikrein could have derived from filtration or from proximal secretion of kallikrein. We conclude that urinary kallikrein enters the urine via secretion in the distal tubule. Filtration or proximal secretion of kallikrein does not contribute significantly to urinary kallikrein excretion.
Genotype and test experience determine responsiveness to morphine.

Initial responsiveness to morphine was studied in two inbred strains of mice, C57BL/6J and DBA/2J, and their F1 hybrid, using both a hot-plate analgesia test and a locomotor-activity test. Three dose levels of morphine were used, 0 mg/kg, 5 mg/kg, and 15 mg/kg. The inclusion of the 0 mg/kg group revealed differences between the inbred strains in the effects of test experience. These data also led to some new conclusions about the differences in responsiveness to morphine between the strains studied. On both tests, the DBA mice showed no effect of morphine, the C57 mice showed large effects, and the F1 mice showed an intermediate effect.
Bile salt supplementation acts via the farnesoid X receptor to alleviate lipopolysaccharide-induced intestinal injury

Background Intestinal barrier integrity may be disrupted in many conditions allowing for bacterial invasion and ensuing systemic illness. We investigated the efficacy and mechanism of bile salts in protecting the intestinal mucosa integrity after injury through stimulation of cell proliferation and an increased resistance to apoptosis. Methods Over 7 days, wild-type C57Bl/6J and Nr1h4 tm1Gonz /J (farnesoid X receptor [FXR] knockout) male mice received either liquid rodent chow alone (for control animals) or with added 50 mg/kg per day of taurodeoxycholic acid (TDCA; for experimental animals). On day 6, all mice received 10 mL/kg of lipopolysaccharide intraperitoneally. On day 7, small intestines were harvested. After immunohistochemistry with hematoxylin and eosin, activated caspase-3, and 5-bromo2′-deoxy-uridine (BrdU), mean proliferating and apoptotic cells were determined with light microscopy. In vitro, FXR proteins were immunoblotted from cultured cells after exposure to TDCA. FXR expression was then inhibited in the presence and absence of TDCA. Intestinal epithelial proliferation along with c-Myc and FXR protein expressions were determined. Results C57Bl/6J mice exhibited significant mucosal enterocyte proliferation and decreased mucosal enterocyte apoptosis when provided with supplemental TDCA in their diet. Inhibition of FXR, both in vivo and in vitro, prevented the bile salt–induced enterocyte proliferation and resistance to apoptosis. TDCA exposure stimulated nuclear translocation of FXR resulting in increased expression of c-Myc. Conclusion A diet supplemented with bile salts, especially in patients who have decreased luminal bile salt, may prove beneficial and therapeutic in critical illness where intestinal injury is part of the spectrum.
Effects of Infant Colic on the Famil Y: Implica Tions for Practice

Infant colic is a little understood phenomenon which has dramatic clinical effects upon the family. This article reports the findings from a Grounded Theory qualitative study that investigated the question of what processes are associated with infant colic in the family. The sample consisted of 50 parents, nurses, and physicians. A Parenting Banking Theory was developed from the data as a metaphor for the social situation that occurs when infant colic behaviors present, A summary concludes with projected areas of need for nursing research, practice, and education for nursing care of families whose infants experience colic.The family nurse and physician are the primary contacts for parents of infants with colic symptoms. This paper presents a theory, based on open-ended interview data, that describes and predicts the family dynamics resulting from the colic experience and hypothesizes interventions. Testing of the theory, especially in the area of intervention and outcomes, is needed. Such testing would se...
Notes on the Psychological Basis of Environmental Design: The Right-Left Dimension in Apartment Floor Plans.

An experiment was conducted to determine right-left preferences in apartment floor plans. Subjects presented mirror image pairs of floor plans demonstrated a strong tendency to select those floor plans with the living room in the far right, rather than the far left, corner. A theoretical interpretation and suggestions for future research are discussed.
Action of Urea and Some of Its Derivatives on Bacteria. V. Antibacterial Activity of Methyl- and Thiourea.∗:

Conclusions1. Methyl- and thiourea are bacteriostatic for Gram-negative bacteria. 2. The substitution of an -XHa group by-CH3 in urea results in no demonstrable increase in antibacterial activity. 3. The replacement of the = O group in urea by -Sincreases markedly the antibacterial activity. 4. Methyl urea, in the concentrations studied, does not potentiate the sulfonamides. It does have a moderate antagonistic effect on p-aminobenzoic acid.
An executable visual formalism for object-oriented conceptual modeling

Conceptual modeling aims at establishing the conceptual knowledge necessary for proper communication between a development team and users. This article presents an executable visual formalism for object-oriented modeling of information systems. This formalism is an integration of the entity-relationship approach, Petri nets, relational calculus, and time temporal logic. It supports integrated and encapsulated modeling of the structural and behavioral aspects of objects, and object evolution. The formalism has textual and graphical representations, allows formal analysis of model properties, and supports rapid prototyping. An environment and a methodology for conceptual modeling also are described.
Network data models for representation of uncertainty

Abstract Network data models have not received the level of attention accorded relational models in fuzzy database research. The lack of formality in the description of form and behavior of network models has served to inhibit deeper probing. Here, a formal definition of the record interrelationships is offered together with a concise logical description of the constraints enforced by DBTG network databases. Three approaches for incorporating imprecision via fuzzy set theory are given together with original nonprocedural query languages. It is found that the greatest barrier to straightforward incorporation of semantics dealing with imprecision is the functionality constraint — the condition that a record may have but a single owner.
Leukoedema of the buccal mucosa in Negro children and youth.

Abstract Leukoedema has been reported to occur only in adult populations. In 1953, Sandstead and Lowe suggested that there may be a tendency for leukoplakia or other keratoses to develop in areas of leukoedema. It was further stated that there is a definite predilection for this lesion in the Negro. The etiology is unknown. In the present investigation the buccal mucosae of 1,000 Negro children and teen-aged patients were examined for leukoedema. An incidence of 50.8 per cent was observed. Histopathologic examination of biopsied leukoedematous specimens failed to demonstrate any features suggestive of dyskeratosis or carcinoma.
Race inequality in epidural use and regional anesthesia failure in labor and birth: An examination of women's experience

Abstract Objective A known racial disparity in medical care is that white women receive epidurals more often in labor than do women from other racial and ethnic groups. Medical researchers have framed this disparity as due to some women's lack of access to anesthesia. Further, an unexamined racial disparity in medical care is that anesthesia failure in labor and birth may also have racial disparity. We explore the organizational processes that may lead to racial disparity an epidural use and regional anesthesia failure in labor and birth. Methods We draw on semi-structured, in-depth interviews conducted with 83 women in June through December, 2010 the day after they gave birth at a New England tertiary care hospital. Results Among women who did not plan to have an epidural, women of color were more likely to face pressure to accept the epidural by hospital medical staff. Further, among women who received anesthesia (either during vaginal delivery or a C-section), women of color were more likely to experience failure in their pain medication and were less likely to have their pain and anxiety taken seriously by doctors. Conclusion Overall we challenge the contention that access is the primary way women's epidural experiences are influenced by race and suggest an alternative lens through which to understand racial dynamics and epidural use and anesthesia failure in labor and birth.
In-flight detection of small hypervelocity particles.

A technique is described in which small (25-micron) hypervelocity (10-km/sec) in-flight particles can be detected in the presence of high background noise. The system is based on a spatial filtering principle whereby spurious noise effects are reduced by use of a beam stop in the entrance aperture of the system and a bandpass filter in the transform plane. A theoretical analysis of the system is presented, and some experimental results are obtained by detecting in-flight hypervelocity particles generated by an exploding lithium wire electrothermal accelerator.
Visualizing and measuring detailed shape and texture with an elastomeric sensor

We have developed a sensor made of clear elastomer which converts distortion due to a contact with a surface into visual images. Using machine vision techniques, we can quantify the surface properties with great detail.
Outlook for many-core systems: Cloudy with a chance of virtualization

The emergence of many-core platforms increases the need for high memory bandwidth, which in turn creates the need for vast amounts of on-chip memory space. Designers must carefully provision the on-chip memory resources to meet application needs. Efficient memory management is extremely critical since it has a great impact on the system's power consumption and throughput. While memory hierarchies have traditionally been based on SRAM-based on-chip caches, the demands of predictability, low power/energy, as well as the emergence of non-volatile memories (NVMs) and mixed-criticality systems, have led to increasing use of software-controlled on-chip memories. The talk presents strategies for efficiently managing software-controlled memories in the many-core domain, while addressing the disparate challenges faced by designers in deploying such memory subsystems (e.g., sharing memory resources, handling variability, and deploying heterogeneous memory families). The overall approach revisits and extends the classical notion of clouds and memory virtualization to handle scalable on-chip memory organizations for reduced power consumption, security, reliability and yield management.
Generic formal fibers of polynomial rings

We construct a noncomplete excellent regular local ring A with maximal ideal M such that the generic formal fiber ring, A⊗AK, (where A is the M-adic completion of A and K is the quotient field of A) is local. In addition, given a small set L of prime ideals of A[[X1,…,Xn]] (where X1,…,Xn are indeterminates) satisfying some necessary conditions, every element of L is in the generic formal fiber of A[X1,…,Xn](M,X1,…,Xn). In other words, Q∩A[X1,…,Xn]=(0) for every Q∈L.
Prosthetic silicone scaphoid strains: Effects of intercarpal fusions

Abstract To assess stress shielding by partial intercarpal fusion, strains within a silicone scaphoid prosthesis were measured in five fresh upper extremities while the wrist was moved through a functional range of motion before and after capitate-lunate and capitate-hamate-lunate-triquetral intercarpal fusions. Capitate-lunate fusions resulted in an overall 18.4% reduction in compressive strains and a 10.8% reduction in tensile strains. Capitate-hamate-lunate-triquetral fusions reduced compressive strains by 28.5% and tensile strains by 26.3%. Radially deviated positions and positions of extension produced no reduction in strains with the partial fusions. Modest strain shielding can be obtained with partial intercarpal fusions. The effect, however, is position dependent, and whether this degree of strain shielding can reduce the incidence of particulate synovitis remains unknown.
Long-term growth in vitro of human cerebrospinal fluid T lymphocytes

Investigations of central nervous system cellular immune reactivity in human disease, as reflected in the responses of cerebrospinal fluid lymphocytes, have been limited primarily due to the low numbers of cerebrospinal fluid lymphocytes available during routine diagnostic lumbar punctures in normal individuals and most patients with demyelinating diseases. We report the use of a T-cell growth factor generated by phytohemagglutinin-stimulated, irradiated normal peripheral blood lymphocytes to maintain long-term proliferating cultures of human cerebrospinal fluid lymphocytes. Cerebrospinal fluid T-cell cultures were initiated from 10 of 14 cerebrospinal fluid samples with up to 5000-fold expansion of initial cell numbers. Few, if any, macrophage or surface immuno-globulin-bearing cells were present, while 80 to 90% of the cultured cells were T cells as demonstrated by rosette formation with sheep red blood cells. Mixed lymphocyte cultures with cultured cerebrospinal fluid T cells and irradiated, freshly isolated allogeneic peripheral blood lymphocytes yielded a positive response in four of the five cultures tested.
Comparison of diagnostic techniques for the detection of a patent foramen ovale in stroke patients.

The prevalence of a patent foramen ovale has been shown to be increased in patients with ischemic stroke. Transesophageal echocardiography, transthoracic echocardiography, and transcranial Doppler examination with contrast injection can all be used to search for a patent foramen ovale. We compared the accuracy of these techniques for identifying a patent foramen ovale in 49 patients with acute ischemic stroke or transient ischemic attack.Transcranial Doppler examination of the right middle cerebral artery was performed during simultaneous transthoracic echocardiography with aerated saline injection, and again during transesophageal echocardiography; the latter was adopted as the "gold standard" for assessing the sensitivity of the other two tests.Contrast transesophageal echocardiography detected a patent foramen ovale in 19 of 49 patients (39%), during normal respiration in 15 of them and during Valsalva maneuver in 4. Transcranial Doppler correctly identified 13 patients with a patent foramen ovale and ...
The fuzzy logic of degenerative disc disease: from a Lorenz attractor to a percolation threshold model.

Apart from a small number of capillaries that penetrate only a few millimeters into the outermost annulus, the normal adult human intervertebral disc is virtually avascular (9). Therefore, the nutrients necessary for the survival of the cells inside the disc (especially glucose and oxygen) are derived mainly from diffusion from vascular channels (which have been called “vascular buds”) present in the limit between the intervertebral disc and the vertebral cartilagenous endplate (3). In a very elegant study, a research group from the Biomedical Engineering Department of the University of Miami investigated the effects of mechanical deformation and anisotropy on the transport of oxygen and glucose in the annulus fibrosus of human intervertebral discs obtained from a tissue bank (7). Using custom-designed chambers (Figure 1A and B), the diffusivities of oxygen and the partition coefficient of glucose were measured under 3 levels of confined uniaxial compression (0%, 10%, and 20%) and in 3 directions (axial, circumferential, and radial) (Figure 1C). The results demonstrated that glucose
Unique Discordance Thoracic Situs Solitus With Left Isomerism

Isomerism is derived from the Greek isos (equal) plus meros (part) and refers to bilateral similarity if not equivalence of structures. A strong association exists between left isomerism and transverse liver with inferior vena caval (IVC) interruption (infrahepatic absence of the IVC). The infrarenal segment of the IVC continues as an azygos or hemiazygos vein that joins the right or left component of bilateral superior vena cavas (SVCs). The azygos vein ascends along the right side of the vertebral column, whereas the hemiazygous ascends along the left side. Thoracic left isomerism is characterized by bilateral morphological left bronchi with bilateral morphological bilobed left lungs. Bilateral SVCs join atrial chambers …
Enthalpies of dilution of aqueous solutions of formamide, acetamide, propionamide, andN,N-dimethylformamide

The enthalpies of dilution of aqueous solutions of formamide, acetamide, propionamide,N,N-dimethylformamide, and sucrose have been measured from about 0.15 to 2.0 moles-kg−1 at 25.0°C. The results of the enthalpy measurements were used to calculate the pairwise enthalpies of interaction for each compound with itself. The equation of Savage and Wood together with their interaction parameters are used to predict the experimental results. All of the predictions are within the standard deviation of the original correlation of Savage and Wood (±220 J-kg-mole−2). Detailed examination of the results shows that specific effects are present but they are less than 220 J-kg-mole−2. Results on urea and substituted ureas are used to determine interaction coefficients for a urea group with itself and with another CH2 group. The result,HU,U=−280 andHU,CH2=29 J-kg-mole−2, is an improvement on the previous arbitrary assignment of parameters for urea interactions.
Deactivation Behavior of Bifunctional Pt/H-Zeolite Catalysts during Cyclopentane Hydroconversion

Abstract Cyclopentane hydroconversion was used as a probe reaction to study the coking behavior of selected large-pore zeolites loaded with 0.5% Pt under identical conditions. The zeolites studied, namely, Y zeolite, zeolite beta, mordenite, LTL, and ZSM-12, were also tested at several different Si/Al ratios. The zeolite pore structure was the most important factor determining the deactivation behavior. Zeolites like Y and L that possess large cavities connected to smaller pore openings allow polyaromatic molecules to form and also trap these coke molecules to a great extent, resulting in rapid deactivation. This was confirmed by the analysis of soluble coke, which revealed the presence of large amounts of benzoperylene and coronene. Zeolite beta, which possesses an intersecting three-dimensional pore system, but no large cages, was the most stable. Apart from its pore structure, the excellent stability of the zeolite beta catalysts could also be partly attributed to the electronic state of platinum in the catalyst. The absence of aromatic compounds in the product stream and the aliphatic nature of coke indicated that the platinum in zeolite beta selectively opened the cyclopentane ring and did not dehydrogenate it, preventing the formation of cyclopentadiene that condenses via a Diels–Alder mechanism into polyaromatic coke. Mordenite and ZSM-12 showed reasonably good stability. Interestingly, the soluble coke in mordenite consisted of both polyaromatic and long-chain aliphatic compounds, indicating that the selectivity of the metal function changes with time. The amount of “hard coke” deposited in the zeolites was strongly related to the initial activity of the acid function, with the more active catalysts having a larger amount of coke. However, this trend was not followed in ZSM-12 which showed a shape-selective behavior that restricted the deposition of hard coke to a great extent. Apart from pore structure, variation of the acid site density (Si/Al ratio) affected metal dispersion and metal/acid balance and caused significant differences in the catalytic performance within a particular type of zeolite. However, the nature of the acid sites (Bronsted or Lewis) did not have a significant effect. Catalysts that had Si/Al ratios in the range 15 to 40 showed a minimum in the C 1 /C 3 ratio indicating a good balance between the metallic and acidic functions and showed good time stability.
Neurospora wc-1 and wc-2: Transcription, Photoresponses, and the Origins of Circadian Rhythmicity

Circadian rhythmicity is universally associated with the ability to perceive light, and the oscillators (“clocks”) giving rise to these rhythms, which are feedback loops based on transcription and translation, are reset by light. Although such loops must contain elements of positive and negative regulation, the clock genes analyzed to date—frq in Neurospora andper and tim in Drosophila—are associated only with negative feedback and their biochemical functions are largely inferred. The white collar–1 and white collar–2 genes, both global regulators of photoresponses inNeurospora, encode DNA binding proteins that contain PAS domains and are believed to act as transcriptional activators. Data shown here suggest that wc-1 is a clock-associated gene andwc-2 is a clock component; both play essential roles in the assembly or operation of the Neurospora circadian oscillator. Thus DNA binding and transcriptional activation can now be associated with a clock gene that may provide a positive element in the feedback loop. In addition, similarities between the PAS-domain regions of molecules involved in light perception and circadian rhythmicity in several organisms suggest an evolutionary link between ancient photoreceptor proteins and more modern proteins required for circadian oscillation.
The determinants of maintenance expenditures in chemical companies

Maintenance expenditures represent more than net profits of several manufacturing companies. Maintenance costs are easy to reduce in a year simply by deferring maintenance activities. Examines maintenance expenditures of US chemical companies from 1975 to 1991. Uses a nonlinear model based on seemingly unrelated regression analysis to identify various factors that influence the expenditures. Uses the ratios of maintenance spending to cost of property, plant and equipment, and buildings (gross plant), cost of property, plant and equipment, and buildings minus accumulated depreciation (net plant) and cost of goods sold as dependent variables. Shows that the age of property, plant and equipment, and buildings, company size, and return on assets have significant influence on the maintenance expenditures. The leverage ratios adversely affect the ratios of maintenance costs to gross plant and net plant.
Ion implantation distributions in inhomogeneous materials

Abstract A simple, approximate, analytical technique for calculating implanted ion depth distributions in inhomogeneous materials is presented. The central concept in the procedure is the method of equivalent atomic stopping (MEAS) wherein an atom of type k in the target is replaced by ϵ k equivalent atoms of a preselected standard species. The target, when viewed as a collection of “equivalent standard atoms” is therefore uniform and thus existing techniques for obtaining depth distributions in the equivalent medium can be applied. The constants ϵ k are shown to be related to range parameters in uniform targets of atoms of type k . The approximation involved in MEAS is examined for the case of low energy implantation by inspection of the properties of Winterbon's generalization of the transport equation. Practical techniques for evaluating the accuracy at higher energies are presented. The method is applied to light and heavy ion implantation into a target consisting of alternating layers of amorphous silicon and germanium, and the results are compared with TRIM calculations. This method is particulary valuable for the initial estimation of appropriate parameters for implantation into complex, layered targets.
On the Response of Different Particle State Sensors to Deliberate Process Variations

Deliberate particle state variations were performed using atmospheric plasma spray (APS) and high-velocity oxy-fuel flame spraying (HVOF) to create a set of first-order process maps. Particle states were measured simultaneously using five in-flight particle sensors: DPV-2000, Accuraspray, SprayWatch, TDS, and SprayCam. While the sensors use similar methods for calculating particle characteristics, absolute values of temperature and velocity were considerably different. Process map trends among sensors are in agreement for the HVOF process, but differ when using plasma spray at high total gas flow conditions. After understanding the stochastic nature of particle detection, an open loop feedback control algorithm was implemented to achieve similar particle states with different hydrogen gas flow rates. The resulting particle state window measured by three different sensors under select fixed hydrogen flow rates was significantly narrowed.
Short‐term oral administration of polybrominated biphenyls enhances the development of hepatic enzyme‐altered foci in initiated rats

FireMaster BP-6 (FM), a commercial mixture of polybrominated biphenyls (PBB), has been shown to act as a tumor promoter in hepatocarcinogenesis assays in rats. Most hepatic tumor promoters must be administered for many weeks or months. Because FM is highly persistent in animal tissues, it was hypothesized that very short-term administration of FM would result in tumor promotion. Female Sprague-Dawley rats weighing 185-215 g were initiated by a two-thirds partial hepatectomy followed by 10 mg diethylnitrosamine/kg body weight (BW) 24 h later. Thirty days later, rats were gavaged with FM in corn oil, at total doses of 0, 13, or 130 mg FM/kg BW. Half the dose was given on d 30, and the remaining half was given 24 h later. At 120 d after gavage the rats were killed and necropsied. Five liver sections from each animal were histochemically stained for gamma-glutamyl transpeptidase-positive enzyme-altered foci (EAF). EAF were significantly increased over control values in initiated rats given 130 mg FM/kg. In animals given 13 mg FM/kg, EAF were increased to a lesser extent but not significantly above controls. Enhancement of these EAF in initiated rats reflects tumor-promoting activity. In this study, 24-h administration of FM in initiated rats was sufficient to enhance hepatic EAF measured 120 d later in an rats was sufficient to enhance hepatic EAF measured 120 d later in an initiation-promotion protocol, and a dose of 13 mg FM/kg was apparently close to a possible no-effect threshold level for enhancement of EAF.
On the rationalization of a sum of surds

A program to rationalize the equations @?^5"i = 1@/y"i = 0 and @?^6"i = 1@/y"i= 0 is described; here y"i are indeterminates. Complete answers are given for these two cases, and for the elementary cases where the sum consists of three or four terms. The rationalization utilizes a family of algorithms treating the algebra of symmetric functions. This is the first step in the construction of a comprehensive computer package-SYMPACK-designed to carry out all useful manipulations of the five basic symmetric functions. The contents of this package, as currently envisaged, is given in outline.
InJection adaptable fine ionization source ('JaFIS') for continuous flow nano-electrospray.

Nanoelectrospray (‘nanoES’) tandem mass spectrometry of complex peptide mixtures has become a certified, mostly reliable technique for the identification of proteins. The typical low flow rates of nanoES, the extended analysis times for small samples, high ion transmission and its overall ease-of-use provide important practical advantages for polypeptide covalent microanalysis. We have constructed a modified nanoES ion source that is highly durable and user-friendly, and potentially allows for full auto-sampling operation. The inJection adaptable Fine Ionization Source (‘JaFIS’) can be operated at flow rates of 10–100 nL per minute and with sensitivities in the 25 femtomoles peptide per microliter range. The ion spray needles usually last for days, allowing for standards and multiple samples to be analyzed consecutively under similar conditions. In this configuration, quality controlled needles can also be saved and reused, providing for more consistent and reproducible day-to-day operating conditions. JaFIS-ES also permits sample recovery should any failure occur during analysis. © 1998 John Wiley & Sons, Ltd.
Pragmatism and Naturalism in Religious Studies

Given the close relationship between pragmatism and naturalism, incorporation of the former into religious studies methodology might seem to privilege the latter. I question this intuition by examining dimensions of pragmatism which suggest that it is more amenable to theism, and less closely tied to naturalism, than many suppose. Pragmatism encourages theoretical openness and reflectivity, which militate against exclusively privileging any particular philosophical perspective. Pragmatism’s most valuable contribution to methodology is the endorsement of a methodological pluralism that relativizes naturalism as one among numerous viable approaches to religious studies.
Optimized antimicrobial dosing strategies: a survey of pediatric hospitals.

Extended-interval aminoglycoside (EIAG) and extended- and continuous-infusion β-lactam (EIBL and CIBL) dosing strategies are increasingly used in adults, but pediatric literature is limited. The objective of this study was to describe the use of EIAG, EIBL, and CIBL dosing in pediatric hospitals in the USA. A national survey of children’s hospitals was conducted. A single practitioner from each target hospital was identified through the Children’s Hospital Association. Practice-based survey questions identified whether hospitals utilize EIAG, EIBL, and CIBL dosing. The main outcome measure was the percentage utilization of the dosing strategies, with secondary outcomes being the reasons for not using these dosing strategies. Seventy-seven of 215 identified practitioners (36 %) participated in the survey. EIAG, EIBL, and CIBL dosing were utilized in 63 %, 24 %, and 13 % of responding hospitals, respectively. The most common reasons for not using EIAG were concern regarding lack of efficacy data (56 %) and concern regarding the duration of the drug-free period (41 %). Respondents who did not utilize EIBL cited concern due to lack of pediatric EIBL efficacy data (54 %), the need for more intravenous access (54 %), intravenous medication compatibility issues (39 %), and the time during which the patient is attached to an intravenous infusion (31 %). This survey of children’s hospitals indicates that EIAG is used in over 50 % of hospitals, but there is some lag in adoption of EIBL and CIBL dosing, both of which are used in fewer than 25 % of hospitals. Additional studies may provide much-needed evidence to increase the utilization of these strategies.
Skin Grafting of the Penis

Penile skin loss may occur after trauma, infection, or as a result of surgical resection. This article reviews indications for reconstruction of the penile skin, skin anatomy, and skin graft physiology. Choice of reconstructive options, skin grafting techniques, and complications of skin grafting are also discussed.
Pathology teach and tell: nasopharyngeal angiofibroma.

(2003). PATHOLOGY TEACH AND TELL: NASOPHARYNGEAL ANGIOFIBROMA. Pediatric Pathology & Molecular Medicine: Vol. 22, No. 4, pp. 363-367.
Will free-ranging predators stop depredating untreated eggs in pulegone-scented gull nests after exposure to pulegone-injected eggs?

Abstract Pulegone is a chemical derived from plants of the mint family ( Mentha spp.) that irritates the trigeminal nerve of mammals when inhaled and causes gastric distress when consumed. We examined whether free-ranging mammalian predators would stop depredating untreated eggs in gulls’ nests that smelled of pulegone. Prior to the nesting period, we distributed pulegone-injected eggs around a gull colony so that local mammalian predators could learn that opening such eggs was painful. We then selected 165 ring-billed gull ( Larus delawarensis ) and 165 California gull ( Larus californicus ) nests in the colony and randomly assigned them to one of the three treatments: (1) nests treated by placing two drops of pulegone (each 1 ml) on the ground on opposite sides of the nest, (2) nests treated by spraying 2 ml of pulegone around the nest's periphery, or (3) nests left untreated as a control. For both gull species, there were no differences among treatments in proportion of nests that were depredated. In a second experiment, which was also preceded by an exposure period when pulegone-injected eggs were distributed, 400 ring-billed and 150 California gull nests located in three colonies were selected to receive one of the two treatments. Half were treated by placing 2 ml of pulegone in a cup and burying it beneath the nest and half were left untreated as a control. Although 30–40% of the control and treated nests were depredated, differences between treated and control nests were not detected. Application of pulegone to nests did not decrease viability of those eggs that escaped depredation. Nevertheless, these results failed to support the hypothesis that egg survival of colonial birds could be increased by training free-ranging predators not to open untreated eggs in pulegone-scented nests.
Smithsonian Centers should receive direct funding

A report by the U.S. National Academies' National Research Council, issued 31 October, has come out in favor of continuing direct federal funding for several science centers that are part of the Smithsonian Institution, including the Smithsonian Astrophysical Observatory. The report, “Funding Smithsonian Scientific Research,” was requested by the White House Office of Management and Budget. OMB had proposed transferring funds from the centers to the National Science Foundation, and had expressed concerns that the centers' research programs are funded without competition.
Passive and active avoidance responses at two levels of shock after administration of melanocyte-stimulating hormone

Abstract Rats receiving either melanocyte-stimulating hormone (MSH) or control solution were tested in a combined active and passive avoidance task involving different visual cues and two levels of shock. The group tested at 0.8 mA had a higher (P