cssi/SciSciGPT-SciSciNet huggingface dataset:
An empirical analysis of virtual goods pricing strategies in virtual worlds

3D Virtual worlds are computer mediated environments intended for the users to inhabit and interact via their representational avatars. Trading virtual goods in 3D virtual worlds plays an important role in realizing the virtual economy. This essay examines the impact of the unique virtual goods permission settings (Copy, Modify, and transfer) on creators’ pricing strategies. We collect data of virtual items from the Second Life marketplace XStreet to explore the factors that affect virtual goods prices. We use ANOVA to test the relationship between each permission and price, and conduct random effects model to investigate how permissions affect price in different categories. Our empirical results show that “Copy” permission, which might be regarded to reduce the profit of the creators, has a positive effect in virtual goods pricing strategies. Virtual items are more likely to be assigned “Copy” which seems to give additional duplicates for free. Furthermore, prices of virtual goods with “Copy” permission are higher than those without, and the more copies a consumer wants, the higher the price difference between the items with “Copy” and those without “Copy” permission. The effects of other issues on virtual goods prices are analyzed and managerial implications are discussed.
vCJD in the United States - Analysis of 4 Cases (I7-2A)

OBJECTIVE: To examine and display a succinct analysis of the 4 confirmed variant Creutzfeldt-Jakob disease (vCJD) cases in the United States and their connection to bovine spongiform encephalopathy (BSE). BACKGROUND: Creutzfeldt-Jakob disease is a rare prion disorder that comes in 3 forms: sporadic, familial and acquired. The last category includes variant CJD, which has been linked to bovine spongiform encephalopathy (BSE) - a prion disorder in cows. Here we review the occurrence of BSE and vCJD in the United States. DESIGN/METHODS: Using publicly available CDC data and case reports including the newest confirmed May 2014 vCJD diagnosed, we compared age at symptom onset, symptom duration, clinical presentation (if known), year of diagnosis and type of neurohistological tissue confirmation. Reported cases of BSE in the United States were also reviewed. RESULTS: As of May 2014, four cases of vCJD have been recognized by the CDC in the United States, all with neuropathological confirmation. These 4 cases exhibit the following: age at onset 22-43, year of onset between 2001-2013, year diagnosed 2002-2014, duration of symptoms from diagnosis <12-32 months, deaths between 2004-May 2014, all confirmed by tonsillar, adenoid and brain tissue at autopsy. Clinical course for all patients included a psychiatric component progressing to dementia. In addition, there have been 3 confirmed United States BSE cases from Dec 2003 (Washington State), June 2005 (Texas, 1st endemic case) and March 2006 (Alabama). CONCLUSIONS: As of May 2014, there have been 4 neuropathologically confirmed vCJD cases in the US and 3 cases of BSE. There is no evidence for indigenous transmission of vCJD in the United States and all 4 affected individuals visited UK at some point during incubation period. The CDC’s surveillance system continues to play a critical role in finding and preventing the spread of variant CJD in the US. Disclosure: Dr. Saenz has nothing to disclose. Dr. Marafie has nothing to disclose. Dr. Maheshwari has nothing to disclose. Dr. Hussein has nothing to disclose.
Phylogenetic distribution of glutathione peroxidase.

Abstract 1. 1. The enzyme glutathione peroxidase (E.C.1.11.1.9), known to be a selenoprotein from mammalian sources, was detected in the following vertebrates: fish, frog, salamander, and turtle. 2. 2. Among invertebrates, the enzyme was detected in crayfish and snail but not in insects or earthworm. 3. 3. No plant tissues or microorganisms showed any evidence of the enzyme activity. 4. 4. The presence of the enzyme activity in so many animal groups implies the widespread occurrence of genetic information for the specific assimilation of the selenium atom.
Commemorative spaces as means of enhancing campus diversity

Purpose – The purpose of this study is to examine commemorative spaces on college campuses as in/effective means of enhancing the collegiate communities’ wealth of diversity. Design/methodology/approach – This research is rooted in both rhetorical communication and higher education theories to maximize our study’s ability to identify potential problems and opportunities for improvement. Upon reviewing the higher education trend of creating commemorative spaces to preserve, educate and celebrate the rich history of minority groups, a case study is provided through which the authors caution about the spaces’ potential relational and rhetorical problems. Findings – This case study reveals that the context and visual rhetoric of a commemorative space is related to its perceived message (whether intended or unintended) and utility in enhancing campus diversity. Originality/value – Explanations and suggestions regarding openings for future understanding, progress and collaboration among institutions of higher e...
Radiation-induced premature menopause: A misconception

Purpose : To disprove the common view that women who have undergone irradiation to fields excluding the pelvis are at risk for radiation-induced premature menopause, we reviewed menstrual function and fertility among women treated with subtotal lymphoid irradiation for Hodgkin's Disease. Methods and Materials : Treatment and follow-up records of all women less than age 50 at the time of diagnosis of Stage I or II supradiaphragmatic Hodgkin's Disease, treated with subtotal lymphoid irradiation alone and enrolled in radiotherapy trials from 1967 to 1985, were reviewed. In addition, patients were surveyed regarding their menstrual status and fertility history. Results : Thirty-six women, aged 10 to 40 years, with normal menstrual function at the time of Hodgkin's diagnosis, were identified. Mean follow-up was 14 years, with a range of 1.25-22.75 years. The average radiation dose to mantle and paraaortic fields was 40-44 Gy ; the calculated scatter radiation dose to the pelvis at the ovaries was 3.2 Gy. There were 38 pregnancies in 18 women ; all offspring are normal. One of 36 women (2.7%) experienced premature menopause. The reported rate of premature menopause in women who have not undergone irradiation is 1-3% ; not significantly different than the rate in our study. There is a syndrome whereby antibodies to several endocrine organs occur (including the ovary), which is associated with premature ovarian failure. This syndrome may be associated with prior radiation to the thyroid, such as that given by mantle irradiation for Hodgkin's Disease. We report such a case. Conclusion : There is little risk of premature menopause in women treated with radiation fields that exclude the pelvis. Women with presumed radiation-induced premature menopause warrant an evaluation to exclude other causes of ovarian failure, such as autoimmune disorders.
Predicting when browsing context is relevant to search

We investigate a representative case of sudden information need change of Web users. By analyzing search engine query logs, we show that the majority of queries submitted by users after browsing documents in the news domain are related to the most recently browsed document. We investigate ways of identifying whether a query is a good candidate for contextualization conditioned on the most recently browsed document by a user. We build a successful classifier for this task, which achieves 96% precision at 90% recall.
The pharmacokinetics of amikacin in children.

The pharmacokinetic variables of amikacin were measured in 20 children and adolescents, four to 16 years of age. The mean plasma clearance of amikacin was 120 ml/minute/1.73 m 2 . The major route of elimination was renal (82%). Simultaneously measured inulin clearance showed that a majority (64%) of the drug filtered by the kidneys was excreted in the urine. The mean volume of distribution of amikacin was 32% of body weight; half-life during the final (pseudoequilibrium) phase averaged 1.6 hours. No significant accumulation of the drug was seen when four doses were given intravenously at 420 mg/m 2 every 8 hours; the plasma concentration just before injection of the fourth dose averaged 2.4±1.1 μg/ml. The mean plasma concentration at 60 to 75 minutes after injection of the drug was 28.7 μg/ml with little interpatient variation (SD 3.5 μg/ml). When the dose was expressed in terms of milligrams per kilogram, it was found that children often needed 50 to 100% more of the drug, compared to adults, to achieve equivalent plasma concentrations; this larger requirement was primarily due to a higher clearance of amikacin in proportion to body weight. Dosages based on surface area, however, resulted in uniform requirements and predictable plasma concentrations in all patients studied.
Time-resolved hole transport in a-SiO/sub 2/

The transport of excess holes in amorphous SiO/sub 2/ is reported as a function of field and temperature, with an emphasis on the behavior at short times (t > or = 10 nsec) after the hole is introduced into the glass. The unusual features of the tranport for t > or approx. = 10/sup -5/ seconds can be rationalized on the basis of the continuous-time random-walk model (CTRW) of Scher and Montroll. It is hypothesized that at short times the hole hops, perhaps as a small polaron, from one oxygen nonbonding orbital to one of the nearest-neighbor oxygen orbitals. The hole is eventually trapped at a structural defect, and the transport continues as a tunneling from one defect to another, this process causes the unusual transport phenomena associated with the CTRW. The temperature dependence of the hole tranport is markedly non-Arrhenius below 200/sup 0/K, which is consistent with the small-polaron model.
The associative nature of lower rank coal

Abstract Initial volumetric swelling in tetrahydrofuran of pyridine-unextracted parts from subbituminous coal and lignite showed no dependence of their concentration, and was smaller than that of their pyridine extracts. These results are opposite to those obtained from high volatile bituminous coals and coincide with predictions for the cross-linked network model of coal. However, when ionic forces in these coals were reduced by acid washing or O-alkylation, these coals showed the same associative nature as did high volatile bituminous coals. Swelling kinetics were analysed on the basis of associative equilibria controlled by the ionic forces. It was concluded that solvation of the ionic forces was the rate determining step of volumetric swelling of lower rank coal rather than solvent diffusion into the coal, although diffusion has been proposed to be the most important factor in swelling.
T1ρ MR Imaging of the Human Wrist in Vivo

Abstract Rationale and Objectives The purpose of this study was ( a ) to demonstrate the feasibility of computing T1ρ maps of, and T1ρ dispersion in, human wrist cartilage at MR imaging in vivo and ( b ) to compare T1ρ and T2 weighting in terms of magnitude of relaxation times and signal intensity contrast. Materials and Methods T2 and T1ρ magnetic resonance images of wrist joints in healthy volunteers ( n = 5) were obtained with a spin-echo sequence and a fast spin-echo sequence pre-encoded with a spin-lock pulse cluster. A 1.5-T clinical imager was used (Signa; GE Medical Systems, Milwaukee, Wis) with a 9.5-cm-diameter transmit-receive quadrature birdcage coil tuned to 63.75 MHz. Results T1ρ relaxation times at a spin-lock frequency of 500 Hz vary from 40.5 msec ± 0.85 to 56.6 msec ± 4.83, and T2 relaxation times vary from 28.1 msec ± 1.88 to 34.5 msec ± 2.63 (mean ± standard error of the mean, n = 5, P Conclusion It was possible to perform T2- and T1ρ-weighted MR imaging of human wrist cartilage in vivo with standard clinical imagers. The higher signal-to-noise ratio and improved contrast between cartilage and surrounding fat achieved with T1ρ imaging may provide better definition of lesions and accurate quantitation of small changes in cartilage degeneration.
Evidence that Fe2+ complexes of 3-aminopicolinate and 3-mercaptopicolinate activate and inhibit phosphoenolpyruvate carboxykinase.

Abstract 3-Mercaptopicolinic acid is known to be an inhibitor of phosphoenolpyruvate carboxykinase and 3-aminopicolinic acid permits Fe 2+ to activate the enzyme. The potency of mercaptopicolinate is increased by incubating the enzyme with Fe 2+ prior to assaying for activity. In the present work, the average combining ratio of either pyridine carboxylate with Fe 2+ at pH 7.5 was determined to be 2:1 when measured by the method of continuous variation of Job or by elemental analysis of the isolated pyridine carboxylate-Fe 2+ complexes. The ratio of 3-mercaptopicolinate or 3-aminopicolinate to Fe 2+ that caused the greatest inhibition or activation of purified phosphoenolpyruvate carboxykinase was 2:1. In the absence of Fe 2+ , neither pyridine carboxylate altered the activity of the enzyme. These results indicate that the two pyridine carboxylates can interact with phosphoenolpyruvate carboxykinase as Fe 2+ coordination complexes.
Increased Sedation Requirements During Endoscopy in Patients with Celiac Disease

Background Celiac disease (CD) is associated with increased rates of neuropsychiatric disease and irritable bowel syndrome, and patients may exhibit visceral hypersensitivity.
Models and methods for studying behavior in polyunsaturated fatty acid research

This report examines a range of models and procedures applicable to polyunsaturated fatty acid (PUFA) research and considers their relative merits. Considerations pertaining to cost, efficiency, and scientific rigor are of particular interest. Parallel activities in other areas of behavioral neuroscience, such as behavioral pharmacology and toxicology, that have profitably exploited various behavior designs for the study of human and animal cognition are noted. Special attention is given to the utility of operant conditioning models and schedules of reinforcement, which are currently underrepresented in PUFA research. Investigations of analogs of complex human behavior as well as implications for generalizing laboratory results to clinical phenomena are addressed.
Ethical Issues in the Use of Putative Father Registries in Infant Adoption: Implications for Administrators and Practitioners

Infant adoption policy and practices are laden with potential ethical dilemmas for adoption professionals, state and federal government, and society in general. Putative father registries raise new...
A macroscopic approach to population genetics

Abstract Conventional population genetics uses as primitive variables the frequencies and fitnesses of individual genes. This paper develops a formalism whose primitive variables are the frequencies and fitnesses of genotypes and environmental histories in a population. From the mathematical relation that describes genetic variation and selection of genotypes and environmental histories we derive a sequence of more specialized equations, including those of the conventional theory. Some familiar formulas of the conventional theory (including Fisher's fundamental theorem, the formula relating the rate of change of a metric character to selection pressure, and the definitions of broad and narrow heritability) are shown to be special cases of simpler and more general formulas. It is shown that the “genotypic value” of a trait, together with its heritability, may depend strongly on genotype-environment correlations. A generalization of Fisher's fundamental theorem shows that the rate of evolution of a trait depends on the skewness of its fitness distribution. An equation relating the second derivative of the mean fitness to the skewness is derived. Finally, the formalism is applied in a preliminary way to a recent theory of genetic variation (Layzer,1978a), according to which the genetic variability of a trait is selected along with the trait itself. It is shown that there is positive feedback between the two kinds of selection.
The effect of d-timolol on intraocular pressure in patients with ocular hypertension.

The stereoisomer form of timolol used in the treatment of glaucoma is l -timolol. Although d -timolol is a less potent beta-adrenergic receptor blocker than l -timolol, several laboratory studies have found that d -timolol has ocular hypotensive effects. Thus, d -timolol may be a useful therapeutic agent for glaucoma that has fewer systemic side effects than l -timolol. We conducted a randomized, double-masked, single-drop study of the effects of d -timolol and placebo on intraocular pressure in 34 patients with ocular hypertension. d -Timolol significantly lowered intraocular pressure for the six-hour duration of the study. No patients receiving the drug reported subjective side effects. There was no change in visual acuity, pupil size, or results of external ocular or slit-lamp examinations during the study. No changes in pulse rate or blood pressure were attributable to the drug.
A range associated with skew symmetric matrix

We study the range where A is an n × n complex skew symmetric matrix. It is a compact convex set. Power inequality s(A2k+1) ≤ s2k+1(A), k ∈ ℕ, for the radius s(A) ≔ maxξ∈S(A) |ξ| is proved. When n = 3, 4, 5, 6, relations between S(A) and the classical numerical range and the k-numerical range are given. Axiomatic characterization of S(A) is given. Sharp points and extreme points are studied.
The response of a non-uniformly tensioned circular string to a moving load

Abstract A non-uniformly tensioned circular string on a damped elastic foundation is acted upon by a moving concentrated load. This configuration can be viewed as a very simplified representation of a spinning rectangularly orthotropic disk acted upon by a spatially fixed force, or of a stationary orthotropic disk subjected to a circumferentially moving load. The natural frequencies and normal modes of vibration of the string on elastic foundation are determined for a range of values of the tension inhomogeneity. The response of the string to a moving load is then determined. The results indicate that there are many speeds, below the critical speed of the uniformly tensioned string, for which the forced response is large. It is anticipated that the response of this simple model to a moving load can provide insight into the behavior of the mathematically more complicated rectangularly orthotropic circular disk.
EVOLUTIONARY AND ECOLOGICAL SIGNIFICANCE OF STARCH STORAGE IN POLLEN OF THE ARACEAE

Starch content was qualitatively assessed for pollen of 79 of the 111 currently recognized genera of the family Araceae-one of three monocot families known to exhibit both starchy and starchless pollen. Although 73% of the genera investigated had exclusively starchy pollen, character correlation suggests that starchless pollen is the primitive type for the family Araceae, as well as for monocots in general. Pollen starch content is a highly conservative character at the generic level in Araceae; only a single genus (Schismatoglottis) clearly exhibits both character states. The distribution of starchy pollen among aroid genera is consistent with what have here been termed Bakers' Starch Laws. Aroid pollen below a certain critical diameter-17-25 ,umis almost invariably starchless. Larger pollen is nearly always starchy, except where insect pollinators may use pollen nutritionally. There is strong evidence that the trend from starchless to starchy pollen in Araceae is reversible, according to the constraints imposed by the afore-
Effect of Oxygen on Taste, Ascorbic Acid Loss and Browning for HTST‐Pasteurized, Single‐Strength Orange Juice

Single-strength orange juice with dissolved oxygen levels of 0.6, 1.8, 6.5, and 10.1 ppm was pasteurized at 85°C for 7 sec using a pilot-scale, high temperature-short time, tubular, heat exchanger. The product was aseptically bottled under nitrogen and stored for 5 months at 22°C. Browning and loss of ascorbic acid were linearly related to the initial oxygen concentration. Based on the results of sensory evaluation, reducing the initial dissolved oxygen concentration by 94% did not extend the shelf-life of single-strength orange juice. Therefore, based on taste, deaeration will not extend the shelf-life of this product.
Considerations in Developing a Functional Approach to the Governance of Large Marine Ecosystems

Interest in the management of the environment and its resources on an ecosystem basis has been increasing, in both terrestrial and marine contexts. In recent years, the concept of the large marine ecosystem has become a point of focus at the national and international levels as a possible unit for management of ocean and coastal areas. An ecosystem approach, however, challenges the manner in which marine resources and the environment that sustains them have been managed in the past. Governance is a key element in ecosystem management and encompasses the formal and informal arrangements, institutions, and mores that determine how resources and the environment are utilized. This study explores some of the problems, concepts, and principles involved in efforts to provide needed governance arrangements if large marine ecosystem-based management is to be implemented and made effective.
Sales force commitment and turnover

Abstract This article investigates salesperson turnover by examining the differing effects of job and organizational commitment on industrial salespeople's propensity to withdraw from selling jobs. Traditional approaches have focused on company turnover thus failing to consider salespeople's attitudinal and behavioral orientations that may lead them to leave selling jobs. The results of this study indicate that organizational commitment is significantly related to withdrawal from an organization.
Integrated vehicle control using steering and brakes

The integration of brakes and steering actuators in vehicle lateral dynamics control is of primary relevance due to the high control authority these actuators insure. Moreover this is a challenging control problem as it is MIMO, intrinsically non-linear due to tyres characteristic and with high plant uncertainty due to variations of major parameters. This paper presents the application of state feedback linearization technique to the problem and shows some vehicle test results. The controller results globally stable, smooth and effective with the steering actuator and uses the braking correction only in critical cases.
Nest tending increases reproductive success, sometimes: environmental effects on paternal care and mate choice in flagfish

Parents should adjust parental care if the costs and benefits of that care vary. Traditionally, the benefit of care has been assumed to be increased offspring fitness, yet increasing evidence indicates that care can also increase mating success. We examined male behaviour and reproductive success across environments in flagfish, Jordanella floridae, a pupfish found across a range of salinities in Florida, U.S.A. Care may be more beneficial to offspring in freshwater habitats than in brackish ones. If so, female preferences for care-giving males should be stronger in fresh water. We quantified male behaviour in fresh and brackish water for four populations and examined whether male behaviour influenced the probability of spawning or the number of eggs spawned. A male's behaviour influenced his reproductive success, but did so differently in fresh and brackish water. In fresh water, the male's behaviour prior to spawning was a strong predictor of whether or not he would spawn, whereas in brackish water, postspawning behaviour of males predicted additional spawning success. These results suggest that the traits that females use to assess potential mates differ depending on the salinity of the environment. Despite the importance to a male's spawning success of different activities in different salinities, male behaviour did not differ consistently between salinities. We discuss possible benefits to females of a phenotypically plastic mate choice criterion and examine explanations for why male behaviour does not covary with the strength of sexual selection across environments.
The absolute luminescence quantum efficiency in hydrogenated amorphous silicon

Abstract Using photothermal deflection spectroscopy in liquid nitrogen, the absolute quantum efficiency of hydrogenated amorphous silicon has been determined to be 19%±10% at ∼72K. Correction for thermal quenching and Auger recombination indicates that the maximum efficiency is only 27%. No significant wavelength dependence is observed. The results suggest that other non-radiative mechansisms are important.
IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS : IX. SPECIFIC PRECIPITATION OF THE FUCOSE OF HOG AND HUMAN BLOOD GROUP A SUBSTANCES BY ANTI-A

Analyses of specific precipitates of hog and human blood group A substances for the amount of fucose precipitable by antibody have shown, that with certain preparations, essentially all of the fucose of the blood group substance is precipitated.
Treatment Considerations for Early Glottic Carcinoma Lessons Learned and a Primer for the General Otolaryngologist

In this commentary, we review our experience with early glottic carcinomas in an attempt to identify points to consider when developing a treatment protocol and technical considerations in oncologic resection to maintain laryngeal function. We highlight several consistent themes: (1) difficult exposure is not always a contraindication to endoscopic resection; (2) depth of invasion may be apparent only intraoperatively; (3) radiation therapy should be offered for deeply invasive cancers requiring extensive cordectomy or for patients who cannot afford lengthy vocal downtime; however, (4) radiation therapy leads to acute dysphagia and collateral damage to the contralateral vocal fold that is avoided with surgery; (5) good voice can be obtained after healing if resection is limited to intramuscular cordectomy; (6) the key to optimal vocal results is adequate glottal closure; and (7) second look operations are occasionally necessary, and therefore preoperative counseling should include this possibility. Since both surgery and radiation therapy achieve excellent oncologic control, a patient-centered approach is preferred in management.
Corrosion resistance of MA5 magnesium alloy with electric-arc coatings

We study the possibilities of increasing the corrosion resistance of MA5 magnesium alloy by applying aluminum electric-arc coatings from D16 and AMg6 solid wires, a mixture of wires of different kinds (D16 + AMg6), and a powder wire in an aluminum sheath with B4 C + Ni Cr B Si mixture. The electrochemical characteristics of these coatings are studied in a 3% NaCl aqueous solution. It is shown that aluminum electric-arc coatings strongly increase the corrosion resistance of the alloy. The best characteristics are exhibited by the AMg6 coatings.
A reduced reaction mechanism for the simulation in ethylene flare combustion

Industrial ethylene flares are considered to be a probable major source of volatile organic compounds (VOCs) such as formaldehyde. VOCs are chemicals that are responsible for the formation of other atmospheric pollutants like ozone. Due to the difficulty and cost of field measurements, on-line monitoring is not practical and other methods must be employed. Current methodologies for calculating speciated and total VOC emissions from flaring activities generally apply a simple mass reduction to the VOC species sent to the flare that does not consider the production of incomplete combustion or other intermediates. There arises a need of a speciation study for the inspection of these flare for their emission. However, most of the detailed kinetic mechanisms for the speciation study of flaring events are too complex, consist of large number of reactions and species, and also are computationally expensive. A reduced mechanism will thus be desirable for improving computational efficiency. In this study, a reduced mechanism for simulating ethylene flare combustion is presented. By retaining the important features of the detailed mechanism in the form of elementary reactions, and satisfying the species constraint of commercial CFD packages, the reduced mechanism, thereby, is useful for speciation study of flaring event.
FINE STRUCTURE OF CELL DIVISION IN PYRAMIMONAS PARKEAE NORRIS AND PEARSON (CHLOROPHYTA, PRASINOPHYCEAE)1

SUMMARY Cell division in Pyramimonas parkeae is described and compared with some other green algae. The first indication of mitosis is division of the chloroplast, accompanied by growth of a prominent microbody, followed by replication of the 4 basal bodies. Also closely timed with this is the replication of the Golgi and other components of the basal body complex. Two basal body complexes separate, each taking a position at either pole of the nucleus which has migrated to a characteristic position just beneath the plasmalemma of a broadened and flattened flagellar pit. Cytokinesis is accomplished by the fusion of ducts and vesicles with the simultaneous release of scales to the newly formed exterior. Cells swim throughout division.
The Mechanics of Neutrophils: Synthetic Modeling of Three Experiments

Much experimental data exist on the mechanical properties of neutrophils, but so far, they have mostly been approached within the framework of liquid droplet models. This has two main drawbacks: 1), It treats the cytoplasm as a single phase when in reality, it is a composite of cytosol and cytoskeleton; and 2), It does not address the problem of active neutrophil deformation and force generation. To fill these lacunae, we develop here a comprehensive continuum-mechanical paradigm of the neutrophil that includes proper treatment of the membrane, cytosol, and cytoskeleton components. We further introduce two models of active force production: a cytoskeletal swelling force and a polymerization force. Armed with these tools, we present computer simulations of three classic experiments: the passive aspiration of a neutrophil into a micropipette, the active extension of a pseudopod by a neutrophil exposed to a local stimulus, and the crawling of a neutrophil inside a micropipette toward a chemoattractant against a varying counterpressure. Principal results include: 1), Membrane cortical tension is a global property of the neutrophil that is affected by local area-increasing shape changes. We argue that there exists an area dilation viscosity caused by the work of unfurling membrane-storing wrinkles and that this viscosity is responsible for much of the regulation of neutrophil deformation. 2), If there is no swelling force of the cytoskeleton, then it must be endowed with a strong cohesive elasticity to prevent phase separation from the cytosol during vigorous suction into a capillary tube. 3), We find that both swelling and polymerization force models are able to provide a unifying fit to the experimental data for the three experiments. However, force production required in the polymerization model is beyond what is expected from a simple short-range Brownian ratchet model. 4), It appears that, in the crawling of neutrophils or other amoeboid cells inside a micropipette, measurement of velocity versus counterpressure curves could provide a determination of whether cytoskeleton-to-cytoskeleton interactions (such as swelling) or cytoskeleton-to-membrane interactions (such as polymerization force) are predominantly responsible for active protrusion.
Bleeding gastric and duodenal ulcers

From the surgical standpoint, the most important step in dealing with serious and persistent bleeding ulcers is to confine the operator’s efforts to the arrest of the hemorrhage since the second stage of the operation eliminates the cause.
The Leader as Mentor

Executive Summary The evolution and mechanics of mentoring are examined as a prelude to arguing that mentoring is a natural component of effective leadership. Pro-social behavioral roots for mentor...
Hydration of N-palmitoylgalactosylsphingosine compared to monosaccharide hydration

Abstract Differential scanning calorimetry (DSC) studies of the ice-water transition of N- palmitoylgalactosylsphingosine (NPGS) (cerebroside)/water mixtures indicate 4 ± 1 non-freezable water molecules per molecule NPGS. This hydration level, representing strongly bound water, is identical to that observed previously for human glucocerebroside (Bach, D., Sela, B. and Miller, I.R. (1982) Chem. Phys. Lipids 31, 381). Comparison of gluco- and galacto-cerebroside hydration with hydration measurements on simple monosaccharides suggests a favored orientation of the glycosyl polar group at the cerebroside-water interface.
A computer analysis of the validity of the integrated Michaelis-Menten equation

Abstract The validity of assumptions made in integrating the Michaelis-Menten equation (i.e. the steady-state assumption) was examined by simulating the model on the digital computer. Time courses thus obtained by numerical integration were compared with data generated by the three most common forms of the integrated equation. Agreement was good within specified limits, the chief exception being the early transient phase of the reaction. The observed differences were very much less than theoretical estimates of the maximum error, even when rate constants were chosen that should exaggerate that error.
Oil demand in the US and Japan: why the demand reductions caused by the price increases of the 1970's won't be reversed by the price declines of the 1980's

Abstract This paper analyzes the imperfect price-reversibility (‘hysteresis’) of oil demand in the US and Japan. We test econometrically oil demand data, disaggregated into transportation oil and non-transportation oil uses. The oil demand reductions following the oil price increases of the 1970's will not be completely reversed by the price cuts of the 1980's. The responce to price cuts in the 1980's is perhaps only one-fifth that for price increases in the 1970's. This has dramatic implications for projections of oil demand, especially under low-price assumptions. We also consider the demand effects of a price recovery in the 1990's, especially whether the effects would be as large as for the price increases of the 1970's or only as large as the smaller demand reversals of the 1980's. On this the results are inconclusive.
Biliary lithotripsy as an adjunct to laparoscopic common bile duct stone extraction.

We investigated various energy sources and delivery systems suitable for fragmentation of common duct calculi by a laparoscopic technique. We evaluated electrohydraulic lithotripsy (EHL) using 1.9-Fr probe delivering 80 W and laser lithotripsy using a 200-μm fiber delivering 30–70 mJ/pulse at 5–20 Hz. In vitro biliary stone fragmentation analysis suggested that the laser lithotripsy produced a more controllable fragmentation than EHL. Initial attempts to employ EHL techniques in animal models resulted in common bile duct injury or inadequate fragmentation of stones. In contrast, biliary lithotripsy was accomplished in pigs using the pulsed-dye laser at 10 Hz and 60 mJ/pulse. Histologic evaluation revealed no evidence of ductal injury related to laser stone fragmentation. Subsequently, laser common duct lithotripsy was used in two human subjects. One patient had a 1.8-cm impacted ampullary stone and one patient had a 3-cm intrahepatic stone. In both cases, the stones were removed laparoscopically after laser fragmentation. Our experience suggests that the laser lithotripsy may facilitate laparoscopic common duct stone extraction procedures.
Cellular and molecular regulation of tumor necrosis factor-alpha production by pentoxofylline

Tumor necrosis factor-alpha (TNF), a mononuclear phagocyte (MO)-derived peptide, is increasingly being recognized for its pleomorphic immunologic effects. A number of investigations have demonstrated that lipopolysaccharide (LPS) can induce TNF synthesis, yet mechanisms that regulate TNF expression at the cellular and molecular levels have not been fully elucidated. In this study, we present data demonstrating pentoxifylline, a methylxanthine, is efficacious in suppressing LPS-induced MO-derived TNF at the level of both TNF mRNA accumulation and TNF supernatant bioactivity. Pentoxifylline, at a dose of 1 x 10-5M, suppressed the production of both biologically active TNF and TNF mRNA expression by more than 50%. Furthermore, additional methylxanthines and dibutyryl cAMP have similar effects on TNF expression. These data support the mechanism for this suppressive effect is via the generation of intracellular cAMP. © 1988 Aoaoe~io P ..... ~no.
Determining shelf life by comparing degradations at elevated temperatures.

The degradation of a biological product follows a specific pattern that depends on the kinetics of the chemical reaction. For most biological and pharmaceutical products, accelerated stability tests are preferred to establish shelf life. We describe a new approach for accelerated stability tests, for situations in which the Arrhenius equation is not appropriate. This approach consists of estimating stability at elevated temperatures and comparing these results with the stability estimates for a similar product with a known shelf life. In this article, “Test” refers to Immuno-Trol™ Low Cells, and “Control” (the product with a known shelf life) refers to Immuno-Trol™ Cells. The degradation rates and stabilities at elevated temperatures of three antigens of the Test are estimated and compared to their respective Control values. Most of the degradation occurs at the beginning of the experimental period and then slows down until it levels off to form a plateau at the minimum level. Both Control and Test showed similar degradation patterns at three elevated temperatures, indicating that they both have the same mechanism of degradation. Thus, it is expected that they will degrade similarly at storage temperature and have nonsignificantly different shelf lives. The approach for accelerated stability testing discussed here is applicable to situations in which the Arrhenius equation is not appropriate, and the chemical properties of both the Test and Control products are similar. J. Clin. Lab. Anal. 18:159–164, 2004. © 2004 Wiley-Liss, Inc.
Study of the Effect of Large Aperture on the Performance of an Ebert Spectrometer

A description of the effect of large aperture upon the resolution limit of an Ebert spectrometer is discussed. The calculations were made by ray tracing on a high-speed computer. Variations of the aberration pattern at the exit slit are noted for several parameter changes which may be useful in design considerations.
Observations of a Pribilof eddy

Abstract Eddies along the eastern shelf-break of the Bering Sea play an important role in the physics, chemistry, and biology of the region. Eddy activity in this region is particularly strong near the major shelf-break canyons during the spring months, likely influencing the spring bloom. Spring eddy activity is negatively correlated with the North Pacific Index, a measure of the strength of the Aleutian Low. A strong Aleutian Low (negative NPI) is related to a strong sub-polar gyre, suggesting that spin-up of the gyre results in more eddy activity in this region. In situ data from an eddy sampled near Pribilof Canyon in 1997 suggest that these eddies can carry water from the outer shelf into the basin. Drifters rotating around the eddy at different radii exhibited differing rotation periods suggesting that the eddy was not rotating in solid body rotation. Thus horizontal exchange of water within the eddy may result in the excess nutrients and fresher water within the core of the eddy exchanging with the basin over time, influencing chlorophyll-a distributions throughout the summer months.
The new nuclear microprobe at Livermore

Abstract Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories/California have jointly constructed a new nuclear microprobe beamline. This beamline is located on the LLNL 10 MV tandem accelerator and can be used for multidisciplinary research using PIXE, PIGE, energy loss tomography, or IBS techniques. Distinctive features of the beamline include incorporation of magnet power supplies into the accelerator control system, computer-controlled object and image slits, automated target positioning to sub-micron resolution, and video optics for beam positioning and observation. Mitigation of vibrations was accomplished with vibration isolators and a rigid beamline design while integral beamline shielding was used to shield from stray magnetic fields. Available detectors include a wavelength dispersive X-ray spectrometer, a High-Purity Germanium detector (HPGe), a Lithium-Drifted Silicon X-Ray detector (SiLi), and solid state surface barrier detectors. Along with beamline performance, results from recent measurements on determination of trace impurities in an International Thermonuclear Experimental Reactor (ITER) super conducting wire strand, determination of Ca/Sr ratios in seashells, and determination of minor and trace element concentrations in sperm cells are presented.
Imperial nostalgia: mythologizing Habsburg Trieste

This article reviews three recently published books on Habsburg Trieste, inquiring into the reasons for increased interest in this topic. The author suggests that this represents a type of 'imperial nostalgia' for the world we have lost, in particular for a political experiment in religious and ethnic diversity (as embodied by the flourishing of imperial Trieste's Jewish community) outside of the nation-state form. This nostalgia, in turn, reflects current concerns with identity, including scholarly attempts to theorize the contemporary situation in which the power of the nation state has been transformed. The analysis reveals that certain authors misread the realities of imperial Trieste through the lens of contemporary meanings of cosmopolitanism and tolerance. As an alternative, the article sketches out what the 'actually existing cosmo­politanism' of the Habsburg city consisted in.
Assessing Competence of Residents to Discuss End-of-Life Issues

Background: Residents are often responsible for eliciting patients' treatment preferences at the end of life (EOL), yet we have a limited understanding of their competence in this task. Objective: To assess the competence of medical residents to discuss advance directives (AD) with patients using two measures: self-assessment (perceived competence) and self-reported behaviors (behavioral competence). To examine the relationship between educational experiences and these two measures of competence. Design: Cross-sectional self-report questionnaire. Subjects: Internal medicine residents from two university- and one community-based program. Results: The 282 respondents (84% response) had an average of 6.2 EOL discussions per month. Few residents reported having received useful feedback from a resident (8%) or an attending (7%) about their ability to discuss ADs. Even fewer reported that work rounds (4%) or attending rounds (5%) were frequently forums for learning about EOL care. Mean perceived competence was ...
Response of cochlear nucleus neurons in the unanesthetized cat to slowly repeated tones

Abstract Extracellular unit recordings were made in the cochlear nucleus of adult decerebrate cats. The responses of 43 units were studied during 206 repetitive tone sequences; each sequence consisted of 25 trials with tone durations and intertone intervals from 1 to 9 s. Control responses were obtained before and after the tone sequences. Many sequences produced response decrements of 25 to 35%; decrements of more than 40% developed during continuous tone stimulation. Decrements were most marked during the initial 5 to 10 trials and approached asymptote thereafter. Spontaneous recovery occurred within the first 10 s and was generally complete by 30 to 40 s. The rate of recovery was not influenced by stimulation beyond asymptote. Significant positive correlations existed between magnitude of decrement and response latency and interspike intervals of the initial four spikes of the response. A weak negative correlation existed between magnitude of decrement and spontaneous activity. Constant-latency units (0.2 ms standard deviation in 10 control trials) did not show onset response decrements but did show decrements in the remainder of their response. Units with more variable latencies showed decrements in both early and late response components.
Plato, Nightingale, and Contemporary Nursing

Purpose: To explore the influence of Plato's ideal of leadership on Nightingale's vision for nursing. Nightingale left her imprint on nursing; greater understanding of Nightingale's legacy clarifies several contemporary problems in the field. Organizing Framework: Qualitative, historical research in which the great person framework is used to focus on Nightingale and Plato. Nightingale's familiarity with Plato, whose work she read in the original Greek, is established. Sources: Evidence for Platonic influence is uncovered in primary sources, then inductive reasoning and reflective analysis are used. Findings: Nightingale's conception of nursing is akin to Plato's conception of public service. Platonic education aims to turn talented people into leading citizens who care for the good of the community. Modern nursing did not evolve from a craft guild tradition, as did medicine. This profound difference in the constitution of nursing is part of what distinguishes it. Conclusions: Reminiscent of Plato's “Republic,” Nightingale's legacy leaves a guardian-like stamp on nursing. Although this legacy also leaves nursing with some ambiguities about technical training and hierarchical systems, it is an orientation to the general good that provides the basis for nursing's holism.
Abstract LB-338: Increased apoptosis and p53 expression in sclerotome of COX-2 transgenic embryo

Cyclooxygenases (COXs) have important functions in various physiological and pathological processes. COX-2 expression is highly induced by a variety of stimuli and is observed during certain periods of embryonic development. We examined the direct effect of COX-2 expression on embryonic development using a novel COX-2 transgenic mouse model which ubiquitously expresses human COX-2 from the early stages of embryonic development. COX-2 transgenic fetuses exhibit severe skeletal malformations and die shortly after birth. Skeletal malformations are localized along the entire vertebral column and rib cage and are linked to defective formation of cartilage anlagen. The cartilage anlagen of axial skeleton fail to properly develop in transgenic embryos because of impaired pre-cartilaginous sclerotomal condensation, which results from the reduction of cell number in the sclerotome. Despite the ubiquitous expression of COX-2, the number of apoptotic cells is highly increased in the sclerotome of transgenic embryos, but not in other tissues, suggesting that it is a tissue-specific response. Therefore, the loss of sclerotomal cells due to an increased apoptosis is likely responsible for axial skeletal malformations in transgenic fetuses. In addition, the sclerotomal accumulation of p53 protein is observed in transgenic embryos. Our result suggests that COX-2 signaling may act upstream of p53 and positively regulate the level of p53. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-338.