cssi/SciSciGPT-SciSciNet huggingface dataset:
Toxicity of Nanoparticles to Brine Shrimp: An Introduction to Nanotoxicity and Interdisciplinary Science.

Nanotoxicity is an area of intense research, stimulated by increased use of nanoparticles in commercially available products. Herein, using nanotoxicity as a platform, we describe an experiment that emphasizes interdisciplinary science in a collaborative work setting while expanding the traditional realm of chemistry and chemistry research. Students synthesize two noble metal nanoparticle suspensions (Au and Ag) and expose brine shrimp to these nanoparticles, assessing the brine shrimp viability after 24 h exposure. By examining two different nanoparticles at several concentrations, with appropriate control conditions, students can work together to collect and analyze all the toxicity results necessary to draw conclusions about the toxicity of Au and Ag nanoparticles. This experiment provides introductory chemistry students hands-on experience with a cutting-edge area of science while showcasing the real-world application of chemistry to an important modern scientific problem, nanoparticle toxicity.
Yeast tRNALeuUAG. Purification, Properties and Determination of the Nucleotide Sequence by Radioactive Derivative Methods

A second major species of leucine tRNA, tRNA Leu UAG (formerly designated tRNA Leu CUA) was purified from baker's yeast in a three-step procedure entailing BD-cellulose chromatography in the presence and absence of Mg2+ and Sephadex G-100 gel filtration. Results of aminoacylation and partial RNase T1 digestion experiments showed that this tRNA retains a native conformation under conditions that denature yeast tRNA Leu m5CAA (tRNA3 Leu). The primary structure of baker's yeast tRNA Leu UAG was elucidated by application of sensitive radioactive isotope derivative ("postlabeling") methods. Complete RNase T1 and A and partial RNase U2 fragments, prepared from non-radioactive tRNA and 5'-half and 3'-half molecules, were separated by two-dimensional polyethyleneimine-cellulose anion-exchange thin-layer chromatography and isolated by a novel micropreparative procedure affording high yields of these compounds in sufficient purity for subsequent tritium derivative analysis. Base composition and sequence of oligonucleotides were analyzed by tritium derivative methods. Molar ratios of the fragments were determined from the radioactivity of 3H-labeled nucleoside trialcohols in combination with base analysis. 2'-O-Methylated guanosine was characterized using the [gamma-32P]ATP/polynucleotide kinase reaction. The analysis of classical complete and partial RNase digests by the tritium derivative methods yielded the complete nucleotide sequence of the tRNA. A total of about 20 A260 units of the RNA was used for analysis, i.e. considerably less material than required for conventional spectrophotometric analysis. A different sequencing approach, consisting of a combination of "readout sequencing" with tritium sequencing of complete RNase T1 and A fragments, was applied to the 3'-half molecule. The 3'-half molecule was labeled with 32P at its 5' terminus, partially degraded with RNase T1, U2, and Phy1 and with alkali, and subjected to polyacrylamide gel electrophoresis. The sequence was read off the gel on the basis of cleavage patterns and size of the fragments. While the readout procedure provided only the positions of A, U, C, and G residues in the chain, additional information from tritium derivative analysis was utilized to define the positions of the modified nucleosides. The readout sequencing procedure was found to require less than 0.01 A260 unit of RNA and the analysis of the complete fragments about 6 A260 units. Interesting structural features of tRNA Leu UAG are (a) the location of unique, leucine tRNA iso-acceptor-specific sequences next to U-8, a constant nucleotide participating in synthetase recognition, (b) the occurrence of 1-methyladenosine in the T loop, a modification not present in the structurally related tRNA Leu m5CAA, and (c) the unusual presence of an unmodified uridine in the first position of the anticodon, which may be related to the unusual coding properties reported for this tRNA.
Performance of the CEA as an e+e- Storage Ring

The Cambridge Electron Accelerator (CEA) has been devoted solely to electron-positron colliding-beam physics since 1970. By early 1972 an operational system had been developed with a peak luminosity of 2 × 1028cm-2sec-1. An experiment observing e+e- , ??, ?+ ?-, and hadron events was then completed at a beam energy of 2 + 2 GeV and an integrated luminosity of 1.12 x 1034cm-2. Since then, many improvements have been made to increase the average luminosity and to permit operation at higher energy. A cryogenic pumping system has been installed close to the interaction region resulting in a significant pressure drop and reduction in background in the luminosity counters. A final experiment is now in progress at a center-of-mass energy of 2.5 + 2.5 GeV, after which the colliding beam physics program will be terminated because higher luminosity is available from the Stanford storage ring SPEAR.
Upper critical field of strongly disordered three-dimensional superconductors: Localization effects

We calculate the influence of localization on the upper critical field, ${H}_{c2}$(T), of strongly disordered superconductors in three dimensions. The present work expands upon our previous paper [L. Coffey, K. A. Muttalib, and K. Levin, Phys. Rev. Lett. 52, 783 (1984)] on this topic. It is our conclusion that studying these field-dependent effects may be the ``cleanest'' way to analyze the interplay of superconductivity and localization phenomena. Our approach is based on the exact impurity eigenstate method which has been used previously to examine both (zero-field) normal-state and superconducting properties of strongly disordered materials. This approach has the advantage over diagrammatic schemes of being nonperturbative in the disorder although it is fundamentally phenomenological in nature. The most striking qualitative effect of extreme disorder is an enhancement of ${H}_{c2}$(T) relative to the standard Werthamer, Helfand, and Hohenberg curve. This occurs at low temperatures corresponding to the high-field suppression of localization. This enhancement has been observed in recent experiments on transition-metal-based alloys. In our approach localization effects in ${H}_{c2}$(T) arise mainly from the field dependence of the Coulomb pseudopotential ${\ensuremath{\mu}}^{\mathrm{*}}$. The changes with H in the density of states and electron-phonon interaction are found to be relatively less important. The pseudopotential depends on the field-dependent particle-hole function ${g}_{H}$(rr';\ensuremath{\omega}) which is closely related to the density-density correlation function. This same function arises in all exact impurity eigenstate calculations for normal as well as superconducting properties. For weak disorder the Fourier transform ${g}_{H}$(q;\ensuremath{\omega})\ensuremath{\approxeq}${D}_{H}$${q}^{2}$/(${\ensuremath{\omega}}^{2}$+${D}_{H}$ $^{2}$${)}^{2}$ where ${D}_{H}$ is the diffusion constant at finite H.Localization effects are assumed to enter ${g}_{H}$(rr';\ensuremath{\omega}) and thus ${\ensuremath{\mu}}^{\mathrm{*}}$ via the scale-dependent diffusion coefficient. Here ${D}_{H}$ is modeled by analogy with scaling laws in the zero-field case. With the application of a high magnetic field these localization effects are suppressed and as a result the Coulomb pseudopotential is reduced. The reduction of localization effects in ${\ensuremath{\mu}}^{\mathrm{*}}$ at high H and the consequent enhancement of ${H}_{c2}$(T) at low T are closely related to the behavior of the negative magnetoresistance. This negative magnetoresistance reflects the same field-induced suppression of localization as does the enhancement of ${H}_{c2}$(T). Therefore an important test of our theory will be a study of systematic correlations in these two phenomena.
Capturing user tests in a multimodal, multidevice informal prototyping tool

Interaction designers are increasingly faced with the challenge of creating interfaces that incorporate multiple input modalities, such as pen and speech, and span multiple devices. Few early stage prototyping tools allow non-programmers to prototype these interfaces. Here we describe CrossWeaver, a tool for informally prototyping multimodal, multidevice user interfaces. This tool embodies the informal prototyping paradigm, leaving design representations in an informal, sketched form, and creates a working prototype from these sketches. CrossWeaver allows a user interface designer to sketch storyboard scenes on the computer, specifying simple multimodal command transitions between scenes. The tool also allows scenes to target different output devices. Prototypes can run across multiple standalone devices simultaneously, processing multimodal input from each one. Thus, a designer can visually create a multimodal prototype for a collaborative meeting or classroom application. CrossWeaver captures all of the user interaction when running a test of a prototype. This input log can quickly be viewed visually for the details of the users' multimodal interaction or it can be replayed across all participating devices, giving the designer information to help him or her analyze and iterate on the interface design.
Post‐Degree Supervision: Existing and Preferred Practices

A survey of National Certified Counselors (NCCs) was conducted to (a) document existing supervision practices and (b) determine the type of supervision these counselors preferred at this point in their careers. Descriptive statistics and chi-square analyses were conducted for the total sample (N=357) and subgroups classified by work setting, counseling experience, degree level, and hours of post-degree supervision. Results indicated that existing practices varied, with school-based respondents receiving the least supervision. A majority of respondents said that they currently were being supervised by noncounseling professionals. Almost every respondent wanted some supervision, and most preferred a supervisor who had additional training in supervision.
Congenital anomalies associated with idiopathic mental retardation

The frequency of associated congenital structural anomalies, including those which are minor in type, was determined for 50 children with idiopathic mental retardation, 50 children with ventricular septal defect, 50 children with cleft lip and palate, and 100 control children. The highest frequency of associated anomalies was found in the group with idiopathic mental retardation. The most significant difference from the control group was the proportion of mentally retarded patients having 3 or more additional defects. None of the children in the control group had this many anomalies in contrast to 42 per cent of those in the mentally retarded group, 18 percent with ventricular septal defect, and 10 per cent of those with cleft lip and palate. The finding of 3 or more associated congenital anomalies in a patient appears to indicate a significant abnormality in prenatal development. The discovery of multiple associated anomalies in a child with idiopathic mental retardation suggests, but certainly does not prove, that the defect of brain function is also a congenital abnormality.
Nationalism, Charisma, and Plebiscitary Leadership: The Problem of Democratization in Max Weber’s Political Sociology

Max Weber has typically been regarded as a central thinker in the liberal tradition of social analysis. At the same time, critics have long noted how his democratic commitments were compromised by his nationalism. Drawing on existing criticism, I discuss the importance of charismatic leadership in Weber’s thought and its implications for his understanding of the process of democratization. Reconstructing core concepts in Weber’s political thought, I analyze how Weber’s concept of plebiscitarian leadership unites charismatic domination with nationalism and skepticism concerning effective democratic politics. I show how Weber’s concept of plebiscitarian rule grew from deeply held political values and his engagement with German politics. I then generate propositions regarding the problem of democratization in regime transitions and apply them to contemporary charismatic leaders and ethno-nationalist mobilization in post-Communist transitions. I argue that as much as it anticipates the central dilemma of charismatic solutions to political crisis, Weber’s thought favors nationalist and plebiscitarian responses to democratization that have been largely discredited by historical experience.
Transverse vibrations of shear-deformable beams using a general higher order theory

A general higher order theory is developed to study the static and vibrational behavior of beam structures having an arbitrary cross section that utilizes both out-of-plane shear-dependent warping and in-plane (anticlastic) deformations. The equations of motion are derived via Hamilton's principle, where the full 3D constitutive relations are used. A simplified version of the general higher-order theory is also presented for beams having an arbitrary cross section that includes out-of-plane shear deformation but assumes that stresses within the cross section and in-plane deformations are negligible. This simplified model, which is accurate for long to moderately short wavelengths, offers substantial improvements over existing higher order theories that are limited to beams with thin rectangular cross sections. The current approach will be very useful in the study of thin-wall closed-cell beams such as airfoil-type sections where the magnitude of shear-related cross-sectional warping is significant.
Pharmacological treatment of social phobia

Abstract Social phobia is characterized by a fear of negative evaluation in social or performance situations and a strong tendency for sufferers to avoid feared social interactions or situations (see also pages 51-5). Over the last few years, several studies have documented the high prevalence and clinical significance of social phobia. At same time, a substantial body of literature has developed that shows that social phobia is quite responsive to psychopharmacological treatment yet approaches in this area are still under-utilized. This contribution reviews medications currently used in the treatment of social phobia (with a particular focus on those studied in placebo-controlled trials) (see Figure 1), and gives guidelines for future directions in research.
Low Temperature Flat Panel Display Driver Circuits in RTP Crystallized Polysilicon

The crystallization of amorphous silicon by rapid thermal processing has some important advantages over other techniques such as laser annealing. This work investigates the characteristics of low temperature polysilicon flat panel display driver circuits fabricated in RTP crystallized polysilicon. Both digital (shift register) and analog (operational amplifier) circuits are presented.
Mitigation of damage from molten fly ash to air-plasma-sprayed thermal barrier coatings

Abstract Ceramic thermal barrier coatings (TBCs) used in gas-turbine engines afford higher operating temperatures, resulting in enhanced efficiencies and performance. However, in the case of syngas-fired engines, fly ash particulate impurities that may be present in syngas can melt on the hotter TBC surfaces and form glassy deposits. These deposits can penetrate the TBCs leading to their failure. In experiments using lignite fly ash to simulate these conditions we show that conventional TBCs of composition 93 wt% ZrO 2 + 7 wt% Y 2 O 3 (7YSZ) fabricated using the air plasma spray (APS) process are completely destroyed by the molten fly ash. The molten fly ash is found to penetrate the full thickness of the TBC. The mechanisms by which this occurs appear to be similar to those observed in degradation of 7YSZ TBCs by molten calcium–magnesium–alumino–silicate (CMAS) sand and by molten volcanic ash in aircraft engines. In contrast, APS TBCs of Gd 2 Zr 2 O 7 composition are highly resistant to attack by molten lignite fly ash under identical conditions, where the molten ash penetrates ∼25% of TBC thickness. This damage mitigation appears to be due to the formation of an impervious, stable crystalline layer at the fly ash/Gd 2 Zr 2 O 7 TBC interface arresting the penetrating molten-fly-ash front.
Ensemble Size Effects on Toluene Hydrogenation and Hydrogen Chemisorption by Supported Bimetallic Particle Catalysts

Silica-supported bimetallic catalysts were prepared by decomposing the molecular clusters Pt2Au4(C⋮CtBu)8 and Pt2Cu4(C⋮CtBu)8. The resulting catalysts were characterized with hydrogen, oxygen, and carbon monoxide chemisorptions. These indicated that CO chemisorption is the preferred method for evaluating metal dispersion. Chemisorption results also suggested that different types of substrate binding sites may be present on the bimetallic particles and that a significant fraction of the available platinum atoms may not be capable of activating hydrogen. Catalytic activity was evaluated with the toluene hydrogenation reaction. The new catalysts were found to be relatively inactive for this reaction at 60 °C, despite having high platinum dispersions. Apparent activation energies for toluene hydrogenation were evaluated with Arrhenius plots. Although activities were low at 60 °C, the cluster-derived catalysts had smaller apparent activation energies than a traditionally prepared Pt/silica catalyst. Trends in ...
Model-independent measurement of the excited fraction in a magneto-optical trap

In many experiments involving a magneto-optical trap (MOT) it is of great importance to know the fraction of atoms placed in an excited state due to the trapping process. Generally speaking, researchers have had to use overly simplistic and untested models to estimate this fraction. In this work, the excited fractions of {sup 87}Rb atoms in a MOT are directly measured using a charge transfer technique, for a range of MOT parameters. Simple models are then fit to the measured fractions. Using the results of this work, the excited fraction of {sup 87}Rb atoms trapped in a MOT can be accurately estimated with knowledge of only the trapping laser intensity and detuning. The results are, at most, only weakly dependent on other MOT parameters.
Simulation of Flow About Rotating Forebodies at High Angles of Attack

A Reynolds-averaged Navier‐Stokes flow solver is used to predict the forces and moments on forebody models at high angle-of-attack rotary conditions. Cases simulated using either a circular or square ogive at an angle of attack of 60 deg, freestream Mach number of 0.21, and Reynolds number based on body diameter of approximately two million are presented and compared against wind-tunnel data from rotary testing on generic forebody models conducted by NASA Langley Research Center and the Defence Research Agency in the United Kingdom. The simulations provide insight into the flow characteristics at steady rotary conditions.
Second law analysis of a low temperature combustion diesel engine: Effect of injection timing and exhaust gas recirculation

Abstract For diesel engines, low temperature combustion (LTC) with a high level of EGR and late injection becomes attractive because of its potential of simultaneous reduction of nitrogen oxides (NOx) and particulate matter (PM) emissions. However, detailed thermodynamic evaluations including second law analysis of the LTC are few. The current work employed an engine cycle simulation incorporating the second law of thermodynamics to evaluate the energy and exergy distribution of various processes in a low temperature combustion diesel engine. After validation with experimental data at eight operating conditions including four different EGR levels and two different injection timings, the model was used to evaluate the effect of EGR level and injection timing on the first and second law parameters. As EGR was increased, intake temperature and equivalence ratio increased. Results showed that for the case at 0% EGR level with conventional injection timing, about 30% of the fuel exergy was destructed during combustion processes, and as EGR level increased to 45% (intake temperature and equivalence ratio also increased), the combustion destructed exergy decreased to 20% of the fuel exergy. This was largely due to the related combustion temperature increase. For both conventional (−6.5° aTDC) and late (1.5° aTDC) injection timings, the percentage of exergy transfer through flows increases as EGR increases, which is attributed to the retarded ignition by increasing EGR. Other parameters such as energy and exergy transfer due to heat transfer, blow-by, and unburned fuel also were determined as a function of EGR level and injection timing.
Chronic parrotfish grazing impedes coral recovery after bleaching

Coral bleaching, in which corals become visibly pale and typically lose their endosymbiotic zooxanthellae (Symbiodinium spp.), increasingly threatens coral reefs worldwide. While the proximal environmental triggers of bleaching are reasonably well understood, considerably less is known concerning physiological and ecological factors that might exacerbate coral bleaching or delay recovery. We report a bleaching event in Belize during September 2004 in which Montastraea spp. corals that had been previously grazed by corallivorous parrotfishes showed a persistent reduction in symbiont density compared to intact colonies. Additionally, grazed corals exhibited greater diversity in the genetic composition of their symbiont communities, changing from uniform ITS2 type C7 Symbiodinium prior to bleaching to mixed assemblages of Symbiodinium types post-bleaching. These results suggest that chronic predation may exacerbate the influence of environmental stressors and, by altering the coral-zooxanthellae symbiosis, such abiotic-biotic interactions may contribute to spatial variation in bleaching processes.
Warfarin-related nephropathy occurs in patients with and without chronic kidney disease and is associated with an increased mortality rate

An acute increase in the international normalized ratio (INR; a comparison of prothrombin time to monitor the effects of warfarin) over 3 in patients with chronic kidney disease (CKD) is often associated with an unexplained acute increase in serum creatinine (SC) and an accelerated progression of CKD. Kidney biopsy in a subset of these patients showed obstruction of the renal tubule by red blood cell casts, and this appears to be the dominant mechanism of the acute kidney injury. We termed this warfarin-related nephropathy (WRN), and previously reported cases of WRN only in patients with CKD. We now assess whether this occurs in patients without CKD, its risk factors, and consequences. In 15,258 patients who initiated warfarin therapy during a 5-year period, 4006 had an INR over 3 and SC measured at the same time; however, the large data set precluded individual patient clinical assessment. A presumptive diagnosis of WRN was made if the SC increased by over 0.3mg/dl within 1 week after the INR exceeded 3 with no record of hemorrhage. WRN occurred in 20.5% of the entire cohort, 33.0% of the CKD cohort, and 16.5% of the no-CKD cohort. Other risk factors included age, diabetes mellitus, hypertension, and cardiovascular disease. The 1-year mortality was 31.1% with compared with 18.9% without WRN, an increased risk of 65%. Thus, WRN may be a common complication of warfarin therapy in high-risk patients and CKD doubles this risk. The mechanisms of these risks are unclear.
Molecular pathogenesis of anemia of chronic disease

Most patients suffering from chronic infections, chronic inflammatory diseases, and some malignancies develop a mild to moderate anemia designated anemia of chronic disease or anemia of inflammation. Patients with this anemia have low serum iron, low to normal transferrin, and high to normal serum ferritin concentration. The anemia is caused by increased inflammatory cytokines, especially IL-6, inducing increased production of the iron-regulatory hormone hepcidin by hepatocytes. Hepcidin blocks the release of iron from macrophages, hepatocytes, and enterocytes, causing the characteristic hypoferremia associated with this anemia and iron-deprivation of the developing erythrocytes.
Using an elastomeric phase mask for sub-100 nm photolithography in the optical near field

Bringing an elastomeric phase mask into conformal contact with a layer of photoresist makes it possible to perform photolithography in the near field of the mask. This technique provides an especially simple method for forming features with sizes of 90–100 nm in photoresist: straight lines, curved lines, and posts, on both curved and planar surfaces. It combines experimental convenience, new optical characteristics, and applicability to nonplanar substrates into a new approach to fabrication. Nanowire polarizers for visible light illustrate one application for this technique.
Inhibition of nicotinic responses at neuromuscular junctions by 3,3-dimethyl-1-butanol carbamate (DBC)

Abstract The action of 3,3-dimethyl-1-butanol carbamate (DBC), a synthetic carbachol analogue in which the quaternary nitrogen atom has been replaced by a carbon atom, has been studied in relation to its effects on nicotinic responses. In the thick biventer cervicis nerve-muscle preparation and frog rectus abdominis muscle preparation, DBC inhibited the responses elicited by nicotine and dimethylphenylpiperazinium at concentrations that did not affect responses induced by acetylcholine. DBC (−4–10−3M) depressed markedly the uptake of 3H-nicotine (2 × 10−3M) into the frog rectus abdominis muscle preparation. In the innervated chick biventer cervicis nerve-muscle preparation, DBC (10−3M) also decreased the uptake of 3H-nicotine (2 × 10−3M), but in denervated preparations, DBC had no effect. It is concluded that the peripheral antinicotinic actions of DBC require an intact nerve-muscle junction and are due to a blockade in the uptake of nicotine into nerve fibers.
Direct Optical Detection of Aptamer Conformational Changes Induced by Target Molecules

Aptamers are single-stranded DNA/RNA oligomers that fold into three-dimensional conformations in the presence of specific molecular targets. Surface-enhanced Raman spectroscopy (SERS) of thiol-bound DNA aptamer self-assembled monolayers on Au nanoshell surfaces provides a direct, label-free detection method for the interaction of DNA aptamers with target molecules. A spectral cross-correlation function, Γ, is shown to be a useful metric to quantify complex changes in the SERS spectra resulting from conformational changes in the aptamer induced by target analytes. While the pristine, unexposed anti-PDGF (PDGF = platelet-derived growth factor) aptamer yields highly reproducible spectra with Γ = 0.91 ± 0.01, following incubation with PDGF, the reproducibility of the SERS spectra is dramatically reduced, yielding Γ =0.67 ± 0.02. This approach also allows us to discriminate the response of a cocaine aptamer to its target from its weaker response to nonspecific analyte molecules.
Overshadowing-like effects between potential comparator stimuli: Covariation in comparator roles of context and punctate excitor used in inhibitory training as a function of excitor salience☆

Abstract Water-deprived rats served in a conditioned lick suppression paradigm designed to probe the associative structure underlying a partially reinforced Pavlovian inhibitor (i.e., A + AX ± ) when Stimulus A (a flashing light) was either of high or low salience. Following inhibition training, subjects received either extinction of A, extinction of the training context alone, or remained in their home cages. The inhibitory potential of Stimulus X (white noise) was then assessed in a neutral context using both a summation test with an excitor other than Stimulus A (Experiment 1) and a retardation test (Experiment 2). When A was of high salience, the inhibitory potential of Stimulus X was directly related to the excitatory value of A and not the excitatory value of the training context. But when A was of low salience, the inhibitory potential of X was directly related to the excitatory value of the training context rather than the excitatory value of A. Although the high salience A, relative to the low salience A, overshadowed the context's role as a modulator of responding to Stimulus X, it did not appreciably overshadow context's potential to directly elicit conditioned responding; thus, a dissociation was seen in the ability of a punctate CS to overshadow a context as a function of the behavioral index of overshadowing. These results are discussed in the framework of the comparator hypothesis.
Global oral health in women and children.

A World Health Organization (WHO) global overview of oral health emphasizes that oral cancer oral manifestations of HIV/AIDS dental trauma craniofacial anomalies and periodontal disease and dental caries have a broad impact on the health and well-being of women throughout the world (Petersen 2005). Many developing countries have shortages of oral healthcare personnel and most often little attention is given to preventive or restorative dental care. Periodontal diseases affect up to 90% of the worlds population and it is known that common forms of periodontal disease have been associated with adverse pregnancy outcomes cardiovascular disease stroke pulmonary disease and diabetes. (excerpt)
Transmission Line Fault Location Algorithms Without Requiring Line Parameters

Abstract When transmission line parameters are not known, a two-terminal algorithm has been proposed in the past for pinpointing the fault location by utilizing voltage and current measurements during the fault. This article puts forth an enhanced method by reducing the number of unknown variables in the Newton-Raphson solution process. The new method is, thus, much simpler and more computationally efficient. In addition, a non-iterative fault location method that is feasible for all types of faults is developed. We have employed the electromagnetic transients program simulation studies to evaluate the performance of the approaches and have obtained quite encouraging results.
Isolated Hypogastric Artery Aneurysms

Iliac artery aneurysms are rare in the absence of concomitant abdominal aortic aneurysm (AAA), and isolated internal iliac (hypogastric) aneurysms in particular are extremely rare. From 1986 to 1997 we repaired 572 aortic and/or iliac artery aneurysms in 440 patients. Among these there were only seven hypogastric aneurysms and three of these occurred in the absence of, or remote to, AAA. Hypogastric aneurysms are difficult to diagnose, and large aneurysms are associated with significant morbidity and mortality due to compression of adjacent structures and a high rate of rupture. They pose technical challenges in repair because of their location deep in the pelvis and because it is difficult to gain distal control of the hypogastric artery and its branches. However, the technique of obliterative endoaneurysmorrhaphy has made repair of these aneurysms safe and straightforward. Moreover, this method, unlike percutaneous endovascular techniques, eliminates the compressive mass that is often associated with significant symptomatology. We report three isolated hypogastric aneurysms repaired over an 11-year period, illustrating the technique of proximal ligation and obliterative endoaneurysmorrhaphy, and review the literature on the topic.
A CONSTRAINED MIXTURE MODEL FOR GROWTH AND REMODELING OF SOFT TISSUES

Not long ago it was thought that the most important characteristics of the mechanics of soft tissues were their complex mechanical properties: they often exhibit nonlinear, anisotropic, nearly inco...
Population characteristics of markets of safety-net and non-safety-net hospitals

To compare and contrast the markets of urban safety-net (USN) hospitals with the markets of other urban hospitals. To develop profiles of the actual inpatient markets of hospitals, we linked 1994 patient-level information from hospital discharge abstracts from nine states with 1990 data at the ZIP code level from the US Census Bureau. Each hospital's market was characterized by its racial and ethnic composition, median household income, poverty rate, and educational attainment. Measures of hospital competition were also calculated for each hospital. The analysis compared the market profiles of USN hospitals to those of other urban hospitals. We also compared the level of hospital competition and financial status of USN and other urban hospitals. The markets of USN hospitals had higher proportions of racial and ethnic minorities and non-English-speaking residents. Adults residing in markets of USN hospitals were less educated. Families living in markets of USN hospitals had lower incomes and were more likely to be living at or below the federal poverty level. USN hospitals and other urban hospitals faced similar levels of competition and had similar margins. However, USN hospitals were more dependent on Medicare disproportionate share payments and on state and local government subsidies to remain solvent. USN hospitals disproportionately serve vulnerable minority and low-income communities that otherwise face financial and cultural barriers to health care. USN hospitals are dependent on the public subsidies they receive from federal, state, and local governments. Public policies and market pressures that affect the viability of USN hospitals place the access to care by vulnerable populations at risk. Public policy that jeopardizes public subsidies places in peril the financial health of these institutions. As Medicare and Medicaid managed care grow, USN hospitals may lose these patient revenues and public subsidies based on their Medicaid and Medicare patient volumes. The loss of these funds would hinder the ability of USN hospitals to finance uncompensated care for uninsured and underinsured patients.
The associations of psychosocial factors and infant feeding beliefs and practices of young, first time, low income mothers.

Background: The purpose of this descriptive, correlational study was to explore associations of maternal psychosocial factors with beliefs and practices related to infant feeding in a sample of young, first-time mothers.Methods: Data were collected from 67 mothers (ages 15–22 years) to assess maternal attributes of self-esteem, depressive symptoms, social support, and beliefs and practices related to infant feeding.Results: Significant multivariate associations were found among the variables of interest with mothers' reports of feeding infants at set times, concern the infant was eating too much, and concern about the infant becoming overweight. Maternal depressive symptoms and social support were found to uniquely contribute to the practice of feeding at set times, while depressive symptoms contributed to concern of the infant eating too much.Conclusions: The findings of this study add to the understanding of young, first-time, mothers' infant feeding beliefs and practices and the particular psychosocial...
CASM (Central's Assembly SiMulator): The Advantages of Using a Simulator to Teach Assembly Language

This article describes an assembly language simulator specifically designed as a pedagogical tool. This simulator has the richness of a stack, procedure calls, and indirect addressing, but prods students into good programming habits without many of the inherent, frustrating aspects of assembly language programming. This is accomplished by providing a syntax checking editor, a powerful debugger, a limited instruction set, and strict attention to eradicating the typical mistakes that assembly language, and high‐level language programmers make.
Dynamical estimation of neuron and network properties II: path integral Monte Carlo methods

Hodgkin–Huxley (HH) models of neuronal membrane dynamics consist of a set of nonlinear differential equations that describe the time-varying conductance of various ion channels. Using observations of voltage alone we show how to estimate the unknown parameters and unobserved state variables of an HH model in the expected circumstance that the measurements are noisy, the model has errors, and the state of the neuron is not known when observations commence. The joint probability distribution of the observed membrane voltage and the unobserved state variables and parameters of these models is a path integral through the model state space. The solution to this integral allows estimation of the parameters and thus a characterization of many biological properties of interest, including channel complement and density, that give rise to a neuron’s electrophysiological behavior. This paper describes a method for directly evaluating the path integral using a Monte Carlo numerical approach. This provides estimates not only of the expected values of model parameters but also of their posterior uncertainty. Using test data simulated from neuronal models comprising several common channels, we show that short (<50 ms) intracellular recordings from neurons stimulated with a complex time-varying current yield accurate and precise estimates of the model parameters as well as accurate predictions of the future behavior of the neuron. We also show that this method is robust to errors in model specification, supporting model development for biological preparations in which the channel expression and other biophysical properties of the neurons are not fully known.
Minimum Requirements for Police Chiefs in the USA

In the USA police chiefs of municipal police departments are usually selected by the mayor or city council, and often recruited from outside the local police department. To date no study has evaluated the minimum employment qualifications required by municipalities for their police chiefs. The present study involved a content analysis of 162 municipal police chief job advertisements in order to determine the minimum requirements needed in order to compete for the position of police chief. The study also attempted to determine if community characteristics such as population size, density, racial diversity, and economic affluence were correlated to the specific minimum requirements communities sought in their chiefs.
Mechanism of the positive inotropic effect of milrinone in cultured embryonic chick ventricular cells

Milrinone, a potent positive inotropic and vasodilating agent, has shown promise in the clinical treatment of congestive heart failure, but significant controversy about its mechanism of action exists. To approach these mechanistic problems in a non-innervated, non-diffusion-limited system, the effects of milrinone on cultured embryonic chick ventricular cells were examined. At 37 degrees C in physiologic buffer, milrinone produced a rapid, concentration-dependent increase in amplitude of contraction that was 45% of the maximum increment in contraction produced by elevated extracellular calcium; the EC50 was 8 microM. This peak response was quantitatively similar to the contractile response produced by isobutyl methylxanthine, a potent phosphodiesterase inhibitor. Milrinone inhibited 70% of total phosphodiesterase activity of cultured ventricular cells with an EC50 of 11 microM. Exposure to 1 X 10(-4) M milrinone resulted in rapid increase in cyclic AMP content to levels greater than 100% above control within 4 min. The same concentration also produced a 43% increase in the rate of transsarcolemmal 45Ca uptake. The stimulation of 45Ca uptake rate was similar to the response produced by 1 microM isoproterenol and could be completely abolished by 10 microM verapamil. Thus, in cultured embryonic chick myocardial cells, the positive inotropic effect of milrinone is largely, if not entirely, attributable to phosphodiesterase inhibition, leading to intracellular cyclic AMP accumulation and stimulation of transsarcolemmal calcium influx via the slow calcium channel.
Dependence of giant magnetoresistance on grain size in Co/Cu multilayers

The effect of grain size on the magnetoresistance (MR) of Co/Cu multilayers fabricated by dc magnetron sputtering has been studied using Co/Cu multilayers grown with identical Co and Cu thicknesses but different grain sizes. These multilayers were selectively fabricated by growing with and without a Cu underlayer: grain-to-grain epitaxy from the buffer layer to the superlattice in the former facilitated control of the multilayer grain structure. The MR was found to increase with increasing grain size, with the difference being larger at low temperature. The enhancement of MR is attributed to an increased electron mean free path leading to sampling of more antiferromagnetically coupled layers.
Perinatal outcomes in women with preterm rupture of membranes between 24 and 32 weeks of gestation and a history of vaginal bleeding.

Objective The purpose of this study was to compare perinatal outcomes among women with conservatively treated preterm premature rupture of membranes at 24 to 32 weeks of gestation in the presence or absence of vaginal bleeding. Study design This is a secondary analysis of 581 women with and without vaginal bleeding within 1 week of admission with preterm premature rupture of membranes at 24 to 32 weeks of gestation who were enrolled in a multicenter trial of antibiotic therapy during conservative treatment. The main outcome was latency to delivery. Other outcome variables included clinical abruptio placentae, amnionitis, perinatal death, severe intraventricular hemorrhage, and respiratory distress syndrome. Results Outcome data were available for 581 patients (n=50 with bleeding). Latency to delivery was not affected by the presence or absence of bleeding. In general, a history of bleeding was associated with higher frequencies of subsequently diagnosed abruptio placentae (12% vs 3.5%; P =.01), perinatal death (16% vs 4.9%; P =.006), intraventricular hemorrhage (14.3% vs 5.9%; P =.03), and respiratory distress syndrome (69.4% vs 40.4%; P P =.002) and had a lower mean gestational age at preterm premature rupture of membranes (27.6 vs 28.5 weeks; P =.02) when compared with white, Hispanic, and other. After an adjustment of data was made for potentially confounding factors, women with recent bleeding were more likely to be diagnosed with abruptio placentae at delivery (odds ratio, 2.8; 95% CI, 1.03-7.8; P =.04), and their infants were more likely to have respiratory distress syndrome (odds ratio, 3.1; 95% CI, 1.5-6.6; P =.004). Conclusion Vaginal bleeding before preterm premature rupture of membranes is associated with increased rates of neonatal respiratory distress syndrome and abruptio placentae, but not with reduced latency to delivery.
Old Wine in New Wineskins

VERY generation is faced with the difficult problem of making the Christian faith relevant and meaningful to the needs and knowledge of its time. Such a venture is never popular, for the "defenders of the faith" are leery of any change. Yet such a revision is not only necessary, but also inevitable. Every aspect of man's experience is subject to growth. Religion is no exception. It is my firm conviction that the Christian gospel needs to be reinterpreted today in a way as revolutionary as Luther's reformation was for his day. This article is one person's testimony as to the direction which today's reformation should take. I believe in God as a result of my own investigation and personal experience. I conceive of God as a Spirit who is personal, yet more than personal as we humans understand personality. It seems to me that God must have at least the highest categories that man has: thinking, feeling, and willing; but far more than that. God is immanent in that He is present with us; He is transcendent in that He is far greater than we are. I like to think of God as a Father if by that term is meant much more than a human father. I feel that I can talk
Some pathological regression asymptotics under stable conditions

Abstract We consider a simple through-the-origin linear regression example introduced by Rousseeuw, van Aelst and Hubert (J. Amer. Stat. Assoc., 94 (1994) 419–434). It is shown that the conventional least squares and least absolute error estimators converge in distribution without normalization and consequently are inconsistent. A class of weighted median regression estimators, including the maximum depth estimator of Rousseeuw and Hubert (J. Amer. Stat. Assoc., 94 (1999) 388–402), are shown to converge at rate n−1. Finally, the maximum likelihood estimator is considered, and we observe that there exist estimators that converge at rate n−2. The results illustrate some interesting, albeit somewhat pathological, aspects of stable-law convergence.
Antagonistic effects of xenobiotics on steroid-induced final maturation of Atlantic croaker oocytes in vitro

The antagonistic effects of Kepone (chlordecone) and o,p'-DDD on maturation-inducing steroid (17α,20β,21-trihydroxy-4-pregnen-3-one, 20β-S) induced final maturation of Atlantic croaker (Micropogonias undulatus). Oocytes were investigated in an in vitro germinal vesicle breakdown (GVBD) bioassay. Exposure to Kepone or o,p'-DDD (100 nM-100 μM) prevented the majority of the oocytes from completing GVBD in response to 20β-S; many of them were arrested at the lipid coalescence or germinal vesicle migration stages when exposed to high xenobiotic concentrations (100 μM). In addition, clearing of the ooplasm, oil droplet formation and hydration were incomplete in xenobiotic-exposed oocytes that underwent GVBD. The xenobiotics inhibited GVBD in a concentration-dependent manner. One minute exposure to either of the xenobiotics was sufficient to block GVBD. Washing the follicle-enclosed oocytes after xenobiotic exposure restored their ability to undergo GVBD in response to 20β-S. These results suggest that o,p'-DDD and Kepone exert antagonistic effects on 20β-S action, possibly by competing for the ovarian 20β-S membrane receptor.
CONSTRAINTS ON COSMIC MAGNETIC MONOPOLES IMPOSED BY THE GALACTIC MAGNETIC FIELD

Constraints on a hypothetical galactic halo of magnetic monopoles imposed by the galactic magnetic field are discussed. If the field is due to electric currents then a disk-stabilizing galactic monopole halo cannot exist unless the monopole mass m/sub M/> or approx. =10/sup 21/ GeV and the monopole flux F/sub M/ or approx. =10/sup 17/ GeV and F/sub M/< or approx. =5 x 10/sup -11/ cm/sup -2/ s/sup -1/.
Failure of Q-switched ruby laser to eradicate atypical-appearing solar lentigo: Report of two cases

Cutaneous lasers, including argon, Q-switched Nd:YAG, Q-switched ruby, Q-switched alexandrite, and short pulsed dye lasers, have been used to treat solar lentigines and other benign melanocytic lesions. However, the effects of these lasers at standard fluences on atypical melanocytic lesions have not been examined. We describe two patients in whom the Q-switched ruby laser failed to successfully treat clinically atypical-appearing solar lentigines. In both, clinically atypical-appearing melanocytic lesions were treated with excellent initial cosmetic results. In the first patient, the pigmentation returned several months after treatment and continued to increase in size and color. A biopsy specimen 30 months after Q-switched ruby laser therapy revealed a lentigo maligna melanoma. In the second patient, the lesion recurred 6 months after Q-switched ruby laser therapy, and a biopsy specimen 1 year after treatment showed an early lentigo maligna. Thus Q-switched ruby lasers and other cutaneous lasers capable of targeting melanin may be inadequate to eliminate lentigo maligna and other atypical melanocytic lesions completely. These cases emphasize the importance of careful clinical assessment before any laser surgery and the need to advise patients to return for evaluation should pigmentation return.
Hispanic Ethnicity and Media Behavior

ABSTRACT This article argues that there is a difference between being Hispanic and possessing Hispanic ethnicity, with the former being a demographic characteristic and the latter a psychological construct. An empirical study of Hispanics revealed the existence of four distinct Hispanic ethnicity segments. The four segments were labeled Strong Hispanics, A-Symbolic Hispanics, Symbolic Hispanics, and Weak Hispanics. The segments were found to possess similar demographic characteristics, but different media preferences and behaviors. Several theoretical and practical implications arising from the study results are discussed.