cssi/SciSciGPT-SciSciNet huggingface dataset:
Stacked Titanium Metaphyseal Cones for Reconstruction of Large Tibial Defects in Revision Knee Arthroplasty.

Abstract Failed total knee arthroplasties with large bone defects are increasing rapidly because of the growing population of young, active patients undergoing primary total knee arthroplasty. There are limited options when tibial metaphyseal bone loss is so extensive that a tibial component with augments and thickest available polyethylene cannot fill flexion and extension gaps once the femoral component is appropriately positioned. Previously, allograft or megaprostheses would be required. However, allografts require contouring and fixation and may not incorporate into surrounding bone. Most endoprostheses do not osseointegrate and are associated with high risk of failure. To our knowledge, we are the first to describe stacked porous titanium cones for reconstruction of massive tibial metaphyseal defects, a straightforward technique with standard revision implants highly likely to osseointegrate.
Retrieval-Monitoring-Feedback (RMF) Technique for Producing Efficient and Durable Student Learning

In this chapter, we overview the Retrieval-Monitoring-Feedback (RMF) technique, a learning technology designed to promote both durable and efficient student learning of key concepts from course material. In the RMF technique, key concepts are first presented for initial study followed by RMF trials. Phase 1 of each RMF trial involves retrieval practice, in which the concept term is presented as a cue and the student attempts to type the correct definition into the computer. In Phase 2 of each trial, the student then monitors the quality of the retrieved response using computer-generated feedback, which helps students evaluate whether their response includes the key ideas comprising the definition. In Phase 3, the correct answer is presented intact for a self-paced restudy opportunity. The RMF program uses the student’s monitoring judgments to schedule subsequent practice trials for each item. Recent research has shown that the RMF technique can yield relatively impressive levels of long-term retention of key concepts. The RMF technique can be used to support learning for materials from many different topic domains and promises to benefit a wide range of learners.
Regenerative braking capability of converter-controlled induction machines

Induction machines are good candidates for traction applications, due to their rugged construction and to their use of low-cost readily available materials. Traction applications typically require that the converter-controlled induction machine be capable of providing both motoring torque and braking torque. It is important to distinguish between regenerative and non-regenerative braking torque modes; the converter-controlled induction machine is a source of electric power in the former mode, but it is a sink of electric power in the latter mode. Although the existing literature discusses regenerative braking operation of induction machines in general terms, no prior work has yet identified the location of the boundary that separates the regenerative and non-regenerative braking regions of converter-controlled induction machines in the torque-speed plane. This paper provides all the analysis required to identify this critical operational boundary, and in the process reveals a fundamental difference between the regenerative braking capability of induction machine drives and permanent-magnet synchronous machine drives in the low speed region. The results of this paper are relevant to the design of power management systems associated with electric and hybrid electric vehicles.
Rain, rock moisture dynamics, and the rapid response of perched groundwater in weathered, fractured argillite underlying a steep hillslope

[1] Various field studies have concluded that shallow groundwater in weathered bedrock underlying hillslopes can contribute to both base and stormflow and thus dominate runoff. The processes associated with recharge from the ground surface, through this unsaturated zone, have received little study, yet they influence runoff dynamics, the chemical evolution of water, and moisture availability. Here we use five measurement systems to document soil and rock moisture dynamics within a 4000 m2zero-order basin in which all runoff occurs through weathered argillite. At this site, the weathered bedrock zone (in which the groundwater fluctuates by 8 m seasonally) varies in depth from ∼4 m at the base of the hillslope to nearly 19 m near the hill top. An aggregate-rich, porous, 0.5 m thick soil overlies the weathered bedrock. We find that during the first rains of the wet season, water rapidly travels meters into the weathered bedrock zone. Consistently, however, groundwater at some places responds quickly to the first major storm, well before the wetting front has been detected much beyond about 1 m. Furthermore, throughout the wet season, the lower portion of the unsaturated weathered bedrock shows little or no moisture change. These observations suggest a fracture-dominated flow path, leading to a highly variably groundwater response across the hillslope for a given storm. Seasonal changes in rock moisture content are greatest in the first 5 to 10 m depth and may exceed the magnitude of moisture changes in the soil, suggesting that it could constitute a significant unmapped moisture reservoir.
Hue-saturation-intensity split-spectrum processing of Seasat radar imagery

Characteristics of terrain features in orbital radar imagery are investigated on the basis of radar physics and the human visual system. Signal scattering, the dominant factor in radar imagery, is caused by look angle and relief displacement. Power spectra characteristics are explored, noting that surface scattering dominates the low frequencies and slope significantly affects the high frequency tone variations. The maximum human visual response has been identified for achromatic scenes as 7 cycles per degree, whereas in radar imagery the low frequency half-power point occurs near 2.5 cycles/deg. Image feature size at a scale of 1:500,000 has been calculated for the maximum human response at 1.25 km. A hue-saturation-intensity transformation is presented for displaying two or three data sets on the same image and is demonstrated for Seasat SAR imagery. The transformation is shown to restore low spatial frequencies to the SAR imagery in order to identify terrain features which would otherwise not be visually discernible.
Heme-binding by Drosophila retinoid- and fatty acid-binding glycoprotein (RFABG), a member of the proapolipophorin gene family.

Abstract We previously have cloned and characterized a retinoid- and fatty acid-binding glycoprotein (RFABG) isolated from the heads of Drosophila melanogaster. The protein is composed of two glycosylated subunits (Mr = >200,000 and 70,000) and is a member of the proapolipophorin gene family. Spectral analysis of purified RFABG revealed an absolute absorbance peak at 405 nm, which is typical for a heme-containing protein. The aim of the present study was to characterize the heme-binding properties of RFABG. Upon saturation of the protein solution with carbon monoxide followed by dithionite reduction, a red shift of the Soret peak to 424 nm and the characteristic α- and β- bands at 567 and 539 nm were observed. Native RFABG contains approximately 0.175 moles of heme (mol/mol) indicating that purified RFABG is primarily the apoprotein. Hemin-agarose affinity chromatography of the native RFABG followed by Western blot analysis showed a single immunoreactive band at 70 kDa, indicating that the heme-binding domain resides in the 70 kDa subunit. Although retinoid and fatty acid also bind to the 70 kDa subunit, no competition was observed when an excess of heme was added to a solution of retinoid or fatty acid bound to RFABG. Heme added to a solution of purified RFABG bound in a saturable manner with an affinity of 3.8 × 10–7 m . Thus, the current study clearly demonstrates that retinoid- and fatty acid-binding glycoprotein is a novel heme-binding protein, which may be involved in the transport and/or metabolism of heme in Drosophila.—Duncan, T., Y. Osawa, R. K. Kutty, G. Kutty, and B. Wiggert. Heme-binding by Drosophila retinoid- and fatty acid-binding glycoprotein (RFABG), a member of the proapolipophorin gene family. J. Lipid Res. 1999. 40: 1222–1228.
Modification of the Versatile Aerosol Concentration Enrichment System (VACES) for conducting inhalation exposures to semi-volatile vapor phase pollutants

Abstract A novel sampling system was developed to provide concentrated vapor phase only semi-volatile organic species for in-vivo exposure studies. The system consists of two units: particles (including their semi-volatile component) are first concentrated by means of the Versatile Aerosol Concentration Enrichment System (VACES), and subsequently drawn through a heating section, in which semi-volatile particle-bound components partition to the gas phase, while non-volatile particles are removed by a quartz filter placed after the heater. The vapors are then cooled to ambient temperatures, without producing nano-particles by nucleation, and can be readily used for exposure studies. Laboratory tests were carried out at various heater temperatures using ammonium sulfate, adipic acid and glutaric acid to investigate the occurrence of nucleation in the cooling section. Subsequently the system was tested in the field with concentrated particle and vapor samples taken upstream of the heater, immediately downstream of the filter, and after the cooling section. Chemical analysis of particle and vapor phases upstream and downstream of the system was conducted for selected polycyclic aromatic hydrocarbons (PAHs), and showed very good PAH recovery. These tests indicate that the modified VACES-heater-filter (VHF) system can provide concentrated PM (including their semi-volatile compounds) and PM-bound semi-volatile species purely in the vapor phase for inhalation exposure studies separately, a feature that makes this system an attractive approach for toxicity studies, particularly in light of the increasing interest in health effects of exposures to multi-pollutant atmospheres.
Flow cytometric characterization of apoptosis and chromatin damage in spermatozoa

Apoptosis has been implicated in sperm chromatin damage; it is unclear whether apoptosis occurs through cytoplasmic or mitochondrial pathways. Sperm has minimal volume of cytoplasm but prominent mitochondria. Propidium iodide (PI), annexin V (AV), DiIC1(5) and proprietary fluorochrome (PF-1) were used to investigate apoptosis activation in human sperm using multichannel flow cytometry. There was a time-dependent increase in staining of spermatozoa with both AV and PF-1 and decrease in mitochondrial staining with DiIC1(5). These results strongly suggest that the drop in mitochondrial potential precedes changes in membrane phospholipids, and thus suggest apoptotic activation through mitochondrial pathway in human spermatozoa.
Saving and the real interest rate in LDCs

Abstract This paper provides emperical evidence on the question of whether savings respond positively to changes in the real rate of interest in LDCs, exploiting some of the implications of the neoclassical theory of consumption. In the first section, it is shown that the emperical success of the high interest elasticity hypothesis can be traced down to the presence of cases of financial reforms in the sample. The second section offers evidence on the elasticity of intertemporal substitution in consumption. The results from both sections point to the presence of very low intertemporal substitution elasticity, as well as negligible responses of aggregate saving to the real rate interest.
Measurement of transistor high-frequency current gain

An approach commonly used in instruments to test the high-frequency current gain of transistors consists of driving the base with a calibrated current source and measuring the collector current with a very low resistance meter. The major shortcomings of such instruments are their insufficient accuracy and their limited range of quiescent test conditions. However, a thorough analysis of this method demonstrates the possibility of reducing the measurement error, in the most unfavorable case, to less than 4.5 per cent as well as the possibility of extending the test conditions to 10µv, 10µa. These improvements were obtained as a result of the development of such features as a source impedance of 50K Ω at 100 Mc, a collector load of 1 Ω and a very low capacitance socket.
Glutamine restores myocardial cytochrome C oxidase activity and improves cardiac function during experimental sepsis.

Background: Cardiac dysfunction occurs commonly in sepsis. Impaired mitochondrial function is a potential cause of sepsis-associated myocardial depression. Cytochrome oxidase (COX), the terminal oxidase of the electron transport chain, is inhibited in the septic heart. Glutamine (GLN) increases Krebs cycle intermediates and supports oxidative phosphorylation. Exogenous GLN has been shown to restore myocardial adenosine triphosphate levels and cardiac function following ischemia–reperfusion injury. The authors hypothesize that exogenous GLN will abrogate sepsis-induced myocardial COX inhibition and improve sepsis-associated myocardial depression. Methods: Under general anesthesia, male Sprague-Dawley rats underwent cecal ligation and double puncture (CLP) or sham operation. At the time of operation, rats underwent intraperitoneal injection of either GLN (0.75 g/kg) or an equal volume of saline. Twenty-four hours after the procedure, animals were killed, cardiac ventricles harvested, and mitochondria isolat...
Obedience as a function of experimenter competence

The purpose of this study was to investigate obedience to an E’s commands as a function of E competency. Based upon Orne’s (1962, 1969) discussion of the demand characteristics inherent in the typical aggression study, it was hypothesized that E incompetence would decrease S obedience. Competence was manipulated by: (1) presenting some Ss with a nervous and inexperienced E, and (2)“accidentally” killing the victim (a rat) midway through the experiment. Thirty-two undergraduate female Ss participated in the experiment—supposedly a study on the physiological effects of stress. Obedi6nce was operationalized as the difference, in simple reaction time, between trials on which Ss were told that their response might result in shock to the rat and trials on which they were told that their response might save the rat from shock. Significant differences in obedience were obtained between competent and incompetent E conditions, and a significant “kill” effect was found in the competent E conditidn. The results of this study suggested that the extreme acts of obedience observed in the laboratory (e.g., Milgram, 1963) occur only when E is perceived as competent. This finding imposes limits on the generalizability of laboratory studies of obedience.
AAMC-loaded cavity-backed slot antennas

Artificial magnetic conductors (AMCs) can enable low-profile antennas over a limited bandwidth. Loading an AMC with negative-inductance non-Foster circuits increases an AMC's bandwidth. We present measurements of two UHF-VHF cavity-backed slot antennas (CBSA) whose cavities are filled with a non-Foster-loaded AMC. The results show that the NFC-AMC CBSA has excellent impedance match that can be tuned over 100 MHz.
Comparison of two slideline methods using ADINA

Two general methods of treating sliding interface problems were implemented in ADINA. The first method uses constraint equations and is based on the work of Taylor, Hughes et al. The second method is a penalty function method where finite stiffnesses are used to simulate the contact forces. This is similar to the method used by Hallquist in NIKE2D. These may be used as notension sliding interfaces, with or without friction, or as a non-sliding interface to interpolate between different mesh regions. We briefly review the theory behind these methods and describe the implementation in ADINA. Several application problems have been run, including metal forming problems. Based on this experience the methods are compared in terms of ease of use, accuracy, reliability, influence on bandwidth, and solution time. Neither method is ideal. The penalty method is generally more efficient but may be inaccurate, whereas the constraint equations are accurate but less efficient.
Mechanism of establishment of cast microstructure during solidification of highly undercooled melts

Abstract A microstructural similarity between highly undercooled 440C alloy steel and the same alloy solidified from a nonundercooled but vigorously stirred melt indicated the role which remelting during recalescence may play in the formation of final cast microstructure in highly undercooled alloys. An experiment was conducted, which firmly established this role for undercooled iron-25% nickel alloy. A remelting model was proposed, predicting that the average length of dendritic segments formed by remelting during recalescence is inversely proportional to the square root of the recalescence rate. This relationship was experimentally verified for iron-25% nickel specimens which were undercooled 150° C and allowed to recalesce at rates ranging from 10° C/sec to 75° C/sec.
Technique for simulating field drought stress in the greenhouse.

(...) A technique was developed to induce drought stress on alfalfa (Medicago sativa L.) in the greenhouse, in a manner conducive to plant acclimation. The technique allows: (i) gradual development of drought stress; (ii) use of plants with large root systems; and (iii) imposition of several cycles of drought. The method uses 90-cm-tall by 20-cm-diam, containers and a growth medium that allows development of plant drought stress within the working range of soil tensiometers. The growth medium, a 2:1 mixture, by volume, of commercial potting mix and coarse sand, is amended with gypsum and slow-release nutrients (...)
Influence of hydroxyl-water interaction on structural transformations during Cs + exchange in microporous H-CST

Crystalline silicotitanate (CST) molecular sieve is being tested as an ion exchanger for targeted removal of Cs from high level radioactive nuclear waste solutions. CST is resistant to high radiation fields and highly alkaline/acidic solutions which make it an ideal sequestration candidate. The mechanisms and dynamics of the crystallographic structural changes involved are the fundamental properties of selectivity in this material, and have not been studied previously. This study investigates the molecular processes of ion exchange in real time using neutron and X-ray diffraction as well molecular dynamics (MD) simulations. These techniques in unison have provided the most complete description of the Cs exchange process in hydrogen form of CST (H-CST). In the H-CST structure, the elliptical channels cannot accommodate Cs due to unacceptable short Cs–O bond distances. From time-resolved X-ray diffraction studies, the elliptical channels in H-CST transform to circular geometry after 8 wt.% Cs exchange. Although structural transformations were observed and the symmetry changed from space group P42/mbc to P42/mcm, the mechanisms were still unknown. Identifying all atom types and positions in the CST structure will ultimately explain the mechanisms of selectivity for Cs in H-CST. Time-resolved and static neutron diffraction studies added the proton positions on the water molecules and hydroxyl units to the model derived from X-ray scattering. The results show that as Cs diffuses through the structure, water molecules must change orientations and positions to hydrate Cs and maintain the hydrogen bond network. The new configuration of the proton on the water sites are closer to the framework and force close proton–proton repulsion with the framework hydroxyl. This repulsion bends the hydroxyl and drives the transformation of the CST structure. Hydroxyl bending and water dynamics have been confirmed using MD simulations. The short timescales of MD simulations is ideal to study these fast molecular motions and emphasizes the important role hydrogen has in CST toward Cs selectivity.
Attention effects of moving and stationary single-element and multiple-element precues: Limits of automaticity

A multiple-element precue (MEP), in which one unique element defines the actual precue, results in efficient precuing for identification of a target. The time course for identification in this case is similar to that for a central precue, even though it is presented peripherally (Chastain, 1996; Chastain & Cheal, in press). Five experiments were conducted to gain further information on the function of MEPs and to question what advantage prior knowledge of the precue may give. In Experiments 1 and 2, it was shown that for “pop-out” features, accuracy of identification of a target was higher if the precue type was known in advance. In contrast, as shown in Experiments 3, 4, and 5, when the precue was defined by apparent motion, there was no difference in accuracy due to advanced knowledge of the precue. Further, accuracy was considerably better for motion precues than for stationary precues.
Form as Content, or, It's All Style

How we say what we say is a part of what we say. In this sense, the form and the content of a statement are inseparable. Style matters semiotically as well as aesthetically. These three assertions are supported by a series of examples from a wide range of verbal and non-verbal sports-historical texts. In accordance with the post-modernist emphasis on reflexivity, several of my examples are taken from my own efforts to ‘do’ history.
Complementation of a vaccinia virus host-range K1L gene deletion by the nonhomologous CP77 gene.

Abstract We investigated the host-range restriction of a vaccinia virus (VV) K1L deletion mutant in rabbit kidney RK13 cells and the ability of the nonhomologous cowpox virus CP77 gene to overcome this block. Viral early mRNAs were made by K1L − VV but early protein synthesis was arrested consistent with a translational block. Replication of viral DNA did not occur and neither intermediate nor late mRNAs or proteins were detected. These results indicated that host-range restriction occurs earlier in RK13 cells than in Chinese hamster ovary cells (CHO) cells infected with CP77 − VV, where the block occurs at translation of intermediate stage mRNA. We confirmed a report (Perkus et al., Virology 179, 276–286, 1990) that the CP77 gene, which allows VV replication in CHO cells, could replace the K1L gene for plaque formation in RK13 cells. However, the size of the plaques formed by K1L − CP77 + VV was smaller than those formed by K1L + CP77 − VV. Single-step growth curves also showed that the CP77 gene could functionally replace the K1L gene, although formation of infectious virus was delayed and did not reach the same level as that of K1L + VV. Most surprisingly, the dramatic shutoff of viral and host gene expression was similar in RK13 cells infected with K1L − CP77 − VV and K1L − CP77 + VV and little difference was noted for the first 6 hr. Subsequently, in cells infected with the K1L − CP77 + VV, viral early protein synthesis was spontaneously resurrected and the replication cycle proceeded. Despite the absence of homology, K1L and CP77 gene products appear to be acting in a common virus/cell interaction pathway.
Asymmetric induction in carboncarbon bond forming reactions of prochiral nucleophiles with electrophiles containing chiral iron centers

Abstract Alkylations of the chiral electrophiles CpFe(CO)(L)CH 2 Cl and CpFe(CO)(L)(CH 2 CH 2 ) + SO 3 CF 3 − (L = PPh 3 and tri( o -biphenyl)phosphite) by the prochiral nucleophiles sodium t-butyl acetoacetate and pyrrolidine cyclohexanone enamine yielded six of the eight possible alkyliron products. The two products where L was o -biphenylphosphite and t-butylacetoacetate was the nucleophile did not form, presumably because of excessive steric hindrance. Relative quantities of the two diastereomers formed in each case were easily determined from the diastereomeric resonances in their NMR spectra. Product ratios from alkylation by acetoacetate were thermodynamic, while those from alkylation by the enamine were presumed to be kinetic. The excess of one diastereomer over the other, relating in principle to an “optical yield” at the new chiral carbon center induced by the existing metal chirality, ranged from 10 to 64% depending on the nucleophile and the electrophile, but most pronouncedly, on the ligand L.
The effect of laminating factors on the thermal properties of unfired multilayer glass-ceramic and alumina substrates

This paper presents experimental data on heat capacities and thermal conductivities of two ceramic tapes measured using standard ASTM methods. The two ceramic tapes were prepared using alumina and a glass ceramic of aluminum-magnesium silicate with poly(vinyl butyral) binder, and laminated at pressures of 20800 to 62000 kPa at two laminating temperatures and times. The measured properties showed that laminating pressures have a greater effect, and that thermal conductivities are affected more than heat capacities. Empirical models have been developed to fit the experimental data. A correlation is developed to express the density of laminated green sheets in terms of the laminating variables-time, temperature, and pressure.
Asymptotic analysis of a crack in a power-law material under combined in-plane and out-of-plane shear loading conditions

Abstract A symptotic crack-tip fields for power-law hardening materials under combined in-plane and out-of-plane shear loading conditions are investigated. The governing equations of the asymptotic crack-tip fields are formulated from two stress functions, one for the in-plane stresses and the other for the out-of-plane shear stresses. These stress functions are of separable functional forms of r and /gq, which represent the polar coordinates centered at the crack tip. Perturbations of the governing equations were carried out. The singular behavior and the angular functions of the crack-tip in-plane and the out-of-plane shear stresses obtained from the perturbation analysis agree well with the results of the finite element computations of P an and S hih ( J. Mech. Phys. Solids 38 , 161, 1990; J. appl. Mech. , in press, 1989). In particular, the results from the perturbation analysis indicate that the singularity of the mode I in-plane stresses is slightly stronger than that of the mode III out-of-plane shear stresses under combined mode I and III conditions, whereas the singularity of the mode III out-of-plane shear stresses is slightly stronger than that of the mode II in-plane stresses under combined mode II and III conditions.
Histamine and cis-urocanic acid augment tumor necrosis factor-alpha mediated induction of keratinocyte intercellular adhesion molecule-1 expression

Early cellular and molecular events in inflamed skin include the active participation of epidermal keratinocytes (KCs) and dermal mast cells which can produce diffusible mediators such as tumor necrosis factor-alpha (TNF-a), histamine, and urocanic acid (UCA). Rapid induction of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) by KCs is observed following a highly diverse array of stimuli which can provoke both irritant, inflammatory, as well as allergic and immune reactions. To determine if the aforementioned mediators could interact in either an additive or synergistic fashion with each other, cultured KCs were exposed to these mediators alone and in combination, and the degree of ICAM-1 mRNA and protein quantitated. Whereas histamine or cis-UCA alone only weakly induced KC ICAM-1, when they were combined with TNF-a, significant augmentation was observed by Northern blot hybridization studies, immunostaining, and FACS analysis. Other histamine derivatives such as L-histidine, 1 methylhistidine, 3-methylhistidine, or all-trans-UCA had no effect. Histamine pretreatment did not affect cell surface high affinity TNF-a receptors, as determined by ligand binding and immunodetection, and did not induce KC TNF-a production. The KC histamine receptor was also characterized and found not to be influenced by TNF-a, cis-UCA, all-trans-UCA, or diphenyhydramine (an H, antagonist), but it was inhibited by cimetidine (an H, antagonist). These results demonstrate that 1) KCs can be induced to express ICAM-1 by exposure to histamine and cis-UCA, 2) histamine and cis-UCA can also augment TNF-a inducible ICAM-1 mRNA and cell surface protein expression, 3) this augmentation does not directly involve changes in KC TNF-a receptor number, affinity, or TNF-a production and, 4) KCs possess a type 2 histamine receptor which is not the photoreceptor for UCA. These findings highlight the potential for cross-talk between molecules produced by resident cutaneous cell types above (i.e., KCs) and below (i.e., mast cells) the epidermal basement membrane zone. These cel Is and their mediators can cooperate to respond to either exogenous or endogenous stimuli leading to rapid and strong KC ICAM-1 expression. Such induction of this important adhesion molecule by KCs ensures the retention of T lymphocytes necessary to participate in the maintenance of cutaneous immunohomeostasis. o 1993 Wiiey-Liss, Inc.
The Use of Time-Lapse P-wave Impedance Inversion to Monitor CO2 Flood At Weyburn Field, Saskatchewan, Canada

In recent years, time-lapse seismic data has been acquired to understand dynamic reservoir characterization. The interpretation of time-lapse data does not only involve amplitude seismic data but also other seismic attributes such as impedance data. In Weyburn Field, the P-impedance inversion method is applied to time-lapse seismic data to monitor the CO2 flood in the thin Midale carbonate reservoir. The P-impedance difference between the baseline and repeated seismic surveys shows CO2 fingering along off-trend permeability zones and also CO2 vertical movement. This information can be used to improve the recovery process in the field.
Atrial regulation of intravascular volume: Observations on the tachycardia-polyuria syndrome

The atria, strategically located at the junction of the venous and arterial circulation, contain a network of neural and humoral structures by which they sense and regulate intravascular volume. Atrial receptors, most commonly consisting of complex unencapsulated nerve endings discharging into myelinated vagal fibers, are located in the intrapericardial portions of the caval and pulmonary veins and the adjacent atrial walls. Receptor activation by atrial distension results in increased afferent vagal fiber discharge, which in turn leads to tachycardia (Bainbridge's reflex) and decreased renal sympathetic nerve activity, renal vasomotor tone, and antidiuretic hormone activity. In addition, atrial distension also releases ANF, a peptide with potent diuretic, natriuretic, and vasorelaxant actions. The combined effect of these neurohumoral changes is the production of a large hypotonic diuresis. In the clinical setting the volume-regulating role of the atria is demonstrated by the tachycardia-polyuria syndrome. Laboratory and clinical evidence points to the activation of atrial neurohumoral mechanisms in response to atrial distension as the mediators of the polyuria that often accompanies paroxysmal tachycardias. The involvement of these mechanisms in other forms of cardiac congestion and the capability to easily measure in the blood an index of atrial distension, namely ANF, provide the opportunity to elucidate the pathophysiology and hence to open new therapeutic avenues in many cardiac disorders.
Risk-based fluconazole prophylaxis of Candida bloodstream infection in a medical intensive care unit.

Candida bloodstream infection (CBSI) accounted for 50% of bloodstream infections in our medical intensive care unit (MICU) in 2004. Our objective was to evaluate a risk-based fluconazole prophylaxis program. CBSI incidence, patient demographics, and unit metrics were retrospectively reviewed for 2004. Starting on January 2005, patients meeting pre-specified criteria were placed on risk-based fluconazole prophylaxis and their outcomes, adverse events, and unit metrics were prospectively collected. The inclusion criteria were based on a clinical prediction rule and included an MICU stay greater than 72 h, broad-spectrum antibiotics, and central venous catheter, along with at least two of the following: mechanical ventilation for at least 48 h, any type of dialysis, parenteral nutrition, pancreatitis, systemic steroids, or other systemic immunosuppressive agents. For 2004, the unit had nine CBSI, corresponding to a rate of 3.4 CBSI/1,000 line-days. Four cases were caused by C. albicans, four by C. glabrata, and one by C. tropicalis. The mean ± standard deviation (SD) APACHE II score for these patients was 25 ± 9. In 2005, a total of 36 patients (2.6% of all unit admissions) received prophylaxis and the unit had two CBSI, corresponding to a rate of 0.79 CBSI/1,000 line-days. One patient had C. albicans and the other had C. tropicalis. The mean ± SD APACHE II score for these patients was 21 ± 8. The mean ± SD duration of fluconazole prophylaxis was 8 ± 6 days. Fluconazole was discontinued in two patients due to non-severe adverse events (acute eosinophilia, elevated transaminases). The attributable cost of CBSI in the unit in 2004 was $63,000 per episode. The total cost for the 36 courses of fluconazole was $6,000. When comparing the 2004 CBSI patients and the 2005 prophylaxis patients, we found similar acuity, demographics, and risk factors, with no differences in MICU or hospital mortality or length of stay. Risk-based fluconazole prophylaxis in an MICU with a high incidence of CBSI was safe and cost-effective when applied to a limited number of patients and produced a significant decrease in the incidence of this disease.
Working with Jewish Undergraduates.

This chapter discusses issues surrounding Americans who identify with Judaism and Jewish student identity development, presents challenges Jewish students face on American college campuses, and offers strategies for faculty and administrators to use when working with Jewish undergraduates.
Depression-like behavior of aged male and female mice is ameliorated with administration of testosterone or its metabolites

There may be a role of age-related decline in androgen production and/or its metabolism for late-onset depression disorders of men and women. Thus, the anti-depressant-like effects of testosterone (T) and its metabolites are of interest. Given that these androgens have disparate mechanisms of action, it is important to begin to characterize and compare their effects in an aged animal model. We hypothesized that there would be sex differences in depression behavior of aged mice and that androgens would reduce depression-like behaviors in the forced swim test. To investigate this, male and female mice (approximately 24 months old) were subcutaneously administered T, or one of its 5alpha-reduced metabolites (dihydrotesterone-DHT, 5alpha-androstane,17beta-diol-3alpha-diol), or aromatized metabolite (estradiol--E(2)), or oil vehicle. Mice were administered androgens (1 mg/kg) 1 h before being tested in the forced swim test, an animal model of depression. We found that males spent more time immobile, and less time swimming, than females. Administration of T, DHT, or 3alpha-diol similarly reduced time spent immobile, and increased time spent struggling, of male and female mice. E(2), compared to vehicle administration, decreased time spent immobile of males and females, but increased time spent swimming of females and time spent struggling of male mice. Together, these data suggest that T and its 5alpha-reduced and aromatized metabolites have anti-depressant-like effects in aged male and female mice.
Bombardment Energy and Fission Product Yield Pattern for Protons on Natural Uranium and U 235

Relative fission yields of ten nuclides produced by proton-induced fission of natural uranium and ${\mathrm{U}}^{235}$ were determined at several proton energies in the range 12 to 20 Mev. The expected trend toward symmetric fission at increased energies is observed. A statistical relation is used to correlate this shift in fission symmetry with the excitation energy of the compound nucleus.
Firms as buyers of last resort

Abstract We develop a model to explore the asset pricing implications of firms being buyers of last resort for their own stocks. Those with more ability to repurchase shares when prices drop far below fundamental value (i.e., less financially constrained firms) should have lower short-horizon return variances (controlling for fundamental variance) than other firms. Using standard proxies for financing constraints such as past repurchases and firm age, we find strong support for this predicted relation. We also find that this relation is stronger in the U.S. after 1982 when regulatory reforms lowered the legal cost of conducting repurchases as well as in countries where share repurchases are legally easier to execute.
Orthopedic considerations in pregnancy

Abstract Almost all pregnant women experience musculoskeletal discomfort during pregnancy, with a good portion of them suffering from severe disability. The purpose of this article is to review normal physiologic musculoskeletal changes of pregnancy and distinguish them from pathological conditions. This article also will offer solutions to reduce patient pain or discomfort and call attention to some serious conditions that must not be over-looked. A review of the literature was done using the MEDLINE database from 1985–1995. Articles regarding low back pain, carpal tunnel syndrome, DeQuervain's tenosynovitis, aseptic necrosis of the femoral head, transient osteoporosis of the hip, and rupture of the symphysis pubis were reviewed. From the data, the author provides information concerning these conditions, identifies patients at risk, and advises obstetricians on how to take a more active role in treatment, and thereby improve pregnant patient's quality of life.
A short interpregnancy interval is a risk factor for preterm birth and its recurrence

Objective We tested the hypothesis that short interpregnancy intervals (IPIs) increase the risk for preterm birth (PTB), recurrence of PTB, and delivery at early extremes of gestational age. Study Design Using the Missouri Department of Health's birth certificate database, we performed a population-based cohort study of 156,330 women who had 2 births from 1989-1997. The association between IPI and subsequent pregnancy outcome was assessed. Results The shortest IPIs ( Conclusion The risk of PTB and its recurrence increases with short IPIs, even after adjustment for coexisting risk factors. This highlights the importance of counseling women with either an initial term or preterm birth to wait at least 12 months between delivery and subsequent conception.
Intracerebral Crises During Treatment of Diabetic Ketoacidosis

Sixty-nine instances of intracerebral complications of diabetic ketoacidosis (DKA), including 29 unpublished occurrences, were analyzed to determine predictive factors, the frequency of other disorders resembling cerebral edema, the effectiveness of intervention to reduce intracranial pressure, and whether any etiologic considerations appeared valid. The review failed to implicate rate of hydration, tonicity of administered fluids, rate of correction of glycemia, or use of bicarbonate. Infants and young children (less than 5 yr of age) were disproportionately represented (33%), as were new-onset patients (62%). Approximately 20% of patients were found to have localized basilar edema, hemorrhage, thromboses, or infection by computed tomography scan or on postmortem examination. The histories of 50% of the patients suggested a period of dramatic neurological change preceding respiratory arrest (RA) during which intervention might be effective. Twenty-three patients were treated for increased intracranial pressure before RA; 13 patients survived in an independent functional state, and 3 survived in a severely disabled or vegetative state. Only 3 of the remaining 46 patients survived normally: 2 were untreated and never developed RA, and 1 was given mannitol at the onset of apnea. This review supports close neurological monitoring and intervention to reduce intracranial pressure when there are definite signs of neurological compromise. However, treatment appears to be successful in only 50% of patients who give sufficient warning for such intervention, and they comprised half of the study population. Therefore, prevention of DKA remains the most important goal to avoid intracerebral complications.
Histological changes in the organs and tissues of migrating and spawning Pacific salmon (genus Oncorhynchus).

A histological study was made of the various organs and tissues of the Pacific salmon at successive stages of sexual maturation from the sea to the spawning grounds. Pronounced changes were found in the body structures of the spawning salmon prior to death. These consisted principally of degeneration with or without atrophy as shown by the stomach, liver, spleen, thymus, thy-roid, gonads, pituitary, kidney and cardiovascular system. On the contrary, certain organs exhibited hypertrophy and hyperplasia, e.g., adrenal, pancreatic islets and skin. The inception of some of the above changes was detected several months before full sexual maturity. Comparison with the histological altera-tions occurring in Cushing’s syndrome, experimental hyperadrenocorticism and aging, suggested that many of the tissue changes found in the salmon could be ascribed to the effects of hyperactivity of the adrenal gland. Previous finding of high concentrations of 17-OHCS in the plasma of spawning salmon lends sup-port to this infe...
Negative social evaluation, but not mere social presence, elicits cortisol responses to a laboratory stressor task.

Background Recent research has supported the premise that performance conditions characterized by social-evaluative threat, in which an aspect of the self could be judged by others, are associated with cortisol responses. However, it remains unclear whether this effect is due to negative social evaluation per se or simply the presence of another during a performance situation. Method In the present study, 89 undergraduates delivered a speech in 1 of 3 conditions: in front of an evaluative audience panel (social-evaluative threat [SET]), in the presence of an inattentive confederate (PRES), or alone in a room (non-SET). Results Consistent with hypotheses, participants in the SET condition demonstrated a significant cortisol response, while those in the non-SET and PRES conditions did not show increases in this hormone. Further, participants in the SET condition who reported greater posttask levels of self-conscious cognitions and emotions demonstrated the greatest increases in cortisol. Conclusion These findings suggest that the mere social presence of others is not driving the changes in cortisol observed under social-evaluative threat; instead, explicit negative social evaluation may be responsible for increases in this health-relevant physiological parameter.
Myocardial infarct size threshold for two-dimensional echocardiographic detection: Sensitivity of systolic wall thickening and endocardial motion abnormalities in small versus large infarcts

This study evaluated the ability of 2-dimensional echocardiography to detect myocardial infarcts of varying sizes. Echocardiography was performed in 29 closed-chest, conscious dogs 2 days after circumflex coronary artery occlusion, and the ultrasonic recordings were analyzed for regional abnormalities in either wall thickening or endocardial motion. Acute myocardial infarct (AMI) size and extent were assessed by morphologic examination. In 5 dogs, coronary occlusion failed to produce AMI; in these dogs wall thickening analysis showed no abnormalities (100% specificity), and endocardial motion analysis yielded 1 false-positive result (80% specificity). In 24 dogs an AMI developed; infarcts larger than 18% of left ventricular mass uniformly resulted in echocardiographically detectable contraction abnormalities. When the AMI was small (1 to 6% of left ventricular mass) and primarily subendocardial, the sensitivity of echocardiography was poor: Only 3 of 10 of the dogs with a small AMI had abnormalities by wall thickening, and only 1 of 10 by endocardial motion. Thus, in this canine model of AMI, 2-dimensional echocardiography was insensitive to small, subendocardial AMI. If this is so in humans as well, it is a potential limitation of the clinical use of echocardiography in the detection of AMI.
Blebbing, free Ca2+ and mitochondrial membrane potential preceding cell death in hepatocytes

Cell surface 'blebbing' is an early consequence of hypoxic and toxic injury to cells. A rise in cytosolic free Ca2+ has been suggested as the stimulus for bleb formation and the final common pathway to irreversible cell injury. Here, using digitized low-light video microscopy, we examine blebbing, cytosolic free Ca2+, mitochondrial membrane potential and loss of cell viability in individual cultured hepatocytes. Unexpectedly, we found that after 'chemical hypoxia' with cyanide and iodoacetate, cytosolic free Ca2+ does not change during bleb formation or before loss of cellular viability. Cell death was precipitated by a sudden breakdown of the plasma membrane permeability barrier, possibly caused by rupture of a cell surface bleb.
Development and cross-validation of a prediction equation for estimating resting energy expenditure in healthy African-American and European-American women

Development and cross-validation of a prediction equation for estimating resting energy expenditure in healthy African-American and European-American women
The effect of ethanol on ion transport in frog skin.

Abstract Frog skin has been used as a model epithelial sodium-transporting system to study the effect of ethanol on ion transport. Treatment of the outside of frog skin with ethanol decreased the net sodium transport due to inhibition of 22 Na + influx. Ethanol did not alter sodium outflux when bathing the outside of the skin. The inhibition was in proportion to the concentration of ethanol, 0.25 M resulting in 50% inhibition. The chloride permeability of the skin was increased several-fold when the skin was exposed to ethanol in either bathing solution. With 0.4 M ethanol in the inner bathing solution, all the unidirectional fluxes of Na + and Cl − were increased. The movement of Cl − was evaluated by comparison of Cl − flux with urea flux, since urea is thought to move passively across frog skin via an extracellular (shunt) pathway. Chloride flux was increased to a greater extent than urea flux. These experiments indicate that ethanol affects chloride permeability beyond an increase in extracellular ion flow and independent of its effect on Na + transport.
Despotism, Status Culture and Social Mobility in an African Kingdom

This paper concerns an idea in which the writer became interested while trying to understand the political institutions of one people – the Baganda of East Africa.1 Fundamentally, however, it is a comparative idea which requires to be tested against a much wider range of data than one person commands. In such circumstances one attempts to achieve a measure of comparative perspective through “reading around” in the history of such other times and places as seem relevant, but amateur groping of this kind is no substitute for criticism by the uniquely wide range of specialists who constitute the clientele of this journal. It is therefore with more than the usual sincerity that the writer invites criticism.
A classification scheme for computational ocean acoustic benchmark problems

Abstract A three-way scheme for classifying the nature and intended purpose of benchmark problems in computational ocean acoustics is proposed. This scheme resolves some ambiguities that have crept into the literature. As new benchmarks are introduced, this scheme will aid researchers in gauging the utility of these benchmarks.