cssi/SciSciGPT-SciSciNet huggingface dataset:
Diet in vitamin A research.

Diet provides all vertebrates with the macronutrients needed for energy production and tissue anabolism, with minerals, such as calcium and phosphorus, that serve a structural role, and with numerous micronutrients that play an essential role as cofactors in metabolism and as regulators of metabolic functions. Thus, a properly formulated diet is essential for practically all in vivo research. In the early 1900s, McCollum and Davis and Osborne and Mendel demonstrated the nutritional requirement for “fat-soluble A” and deduced several of the vitamin’s most important effects. It is now well established that all vertebrates require vitamin A for adequate growth, cell and tissue differentiation, vision, development and function of the immune system, and survival. Although the amount of vitamin A (retinol) required for these functions, in the range of μg/day (1), is a trace component of the diet, its biological impact is wide ranging. This chapter focuses on the practical use of diet in retinoid research from two perspectives: human diets, and animal (rodent) diets. In human research on vitamin A, vitamin A intake is seldom controlled, although this has been done in a few studies. However, the assessment of vitamin A intake is important in population-based and epidemiological research. Humans consume a variety of foods and thus obtain their vitamin A in multiple forms--preformed retinol and provitamin A carotenoids– and the variable consumption of different foods contributes significantly to the problem of analyzing how much vitamin A has been consumed. In contrast, for animal studies diet is a controllable factor and the diet is usually the same over time. The amount of vitamin A present in the diet establishes the animal’s vitamin A status, which, in turn, can determine outcomes, such as levels of gene expression and rates of metabolic processes. However, many standard animal diets are nonpurified and the vitamin A content can be variable. It is hoped that a discussion of diets in human and animal research will assist investigators interested in the molecular biology of retinoids in making the best decisions regarding the design of their future human and animal research.
A motivationally-based simulation of performance degradation under pressure

The CLARION cognitive architecture has been shown to be capable of simulating and explaining a wide range of psychological tasks and data. Currently, two theories exist to explain the psychological phenomenon of performance degradation under pressure: the distraction theory and the explicit-monitoring theory. However, neither provides a detailed mechanistic explanation of the exact processes involved. We propose such a detailed theory within the CLARION cognitive architecture that takes into account motivation and the interaction between explicit and implicit processes. We then use our theory to provide a plausible explanation of some existing data. The data are simulated using the theory within the CLARION cognitive architecture.
Abstract B32: A novel combination therapy for metastatic melanoma potentiates a gap junction positive feedback mechanism

We have developed a novel approach for treating melanoma by selectively targeting cancer cells with reactive oxygen species (ROS). This combination therapy incorporates ROS generated by 1) nonthermal plasma (NTP) that emits a multitude of ROS and 2) SR-4233 (TPZ) that undergoes a chemical change to become a ROS only in conditions of hypoxia. The results show an additive to synergistic effect of the combination therapy as compared to each agent individually. Since gap junctions promote the intercellular communication of small molecules up to 1 kDa, we assessed the effect of this combination therapy on metastatic melanoma with functional and nonfunctional gap junctions. We utilized 1205Lu metastatic melanoma cells expressing an empty vector, overexpressing a wild-type Cx43, or a dominant negative variant. The results demonstrated that NTP induced a highly localized cell death in the target area whereas TPZ partially reduced viability over the total surface area. However, when the combination of NTP/TPZ therapy was delivered, complete cell death was observed across the entire plate, specifically in the cells expressing high gap junctions. Similarly, in vivo studies of human metastatic melanoma in a mouse tumor model demonstrated a 90% reduction in tumor volume when treated with the combination of NTP/TPZ in high gap junction expressing tumors. Treatment with NTP/TPZ increased expression of genes activated by apoptosis and oxidative stress while decreasing genes related to cell migration. Microarray analysis also demonstrated a high induction of interleukins and cytokines, indicative of the potential for an immune response. In addition, the transcription factor, HIF1α, known to promote tumor progression, was decreased only under the conditions of NTP/TPZ with high gap junctions. Interestingly, the connexin protein, Cx26, was upregulated following treatment with NTP/TPZ, and the associated gap junctions were shown to maintain functionality during the onset of treatment. Therefore, we conclude that gap junctions both increase the efficacy of NTP/TPZ and are induced by the therapy, thus promoting a positive feedback mechanism of tumoricidal activity. Our unique approach to ROS induction in melanoma cells with NTP/TPZ shows preclinical efficacy, suggesting potential as a novel cancer treatment. Citation Format: Archis Bagati, Zethan Koch, Timothy C. Hutcherson, Joseph Pechette, Hossein Dianat, Cory Higley, Lisa Chiu, Yesul Song, Jay Shah, Elana Chazen, Andrew Nicolais, Peter Casey, Kyle Thompson, Mikhail A. Nikiforov, Jennifer Zirnheld, Shoshanna N. Zucker. A novel combination therapy for metastatic melanoma potentiates a gap junction positive feedback mechanism [abstract]. In: Proceedings of the AACR Special Conference on Melanoma: From Biology to Target; 2019 Jan 15-18; Houston, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(19 Suppl):Abstract nr B32.
Low Prenatal Vitamin D Metabolite Ratio and Subsequent Postpartum Depression Risk.

Background: Depression is a common complication of pregnancy and vitamin D deficiency is one biological risk factor for postpartum depression (PPD). Materials and Methods: We evaluated the ratio of...
Hyperpartisan News Use: Relationships with Partisanship and Cognitive and Affective Involvement

This paper revisits the issue of partisan selectivity in the era of prevalent false, misleading, and biased information. We surveyed a representative sample of adults living in the United States to...
On the Normalization of the QSO Lyα Forest Power Spectrum

The calculation of the transmission power spectrum of QSO Lyα absorption requires two parameters for the normalization: the continuum Fc and mean transmission -τ. Traditionally, the continuum is obtained by a polynomial fitting truncating it at a lower order, and the mean transmission is calculated over the entire wavelength range considered. The flux F is then normalized by Fc-τ. However, the fluctuations in the transmitted flux are significantly correlated with the local background flux on scales for which the field is intermittent. As a consequence, the normalization of the entire power spectrum by an overall mean transmission -τ will overlook the effect of the fluctuation-background correlation upon the powers. In this paper we develop a self-normalization algorithm of the transmission power spectrum based on a multiresolution analysis. This self-normalized power spectrum estimator needs neither a continuum fitting nor a predetermining of the mean transmission. With simulated samples, we show that the self-normalization algorithm can perfectly recover the transmission power spectrum from the flux regardless of how the continuum varies with wavelength. We also show that the self-normalized power spectrum is also properly normalized by the mean transmission. Moreover, this power spectrum estimator is sensitive to the nonlinear behavior of the field. That is, the self-normalized power spectrum estimator can distinguish between fields with or without the fluctuation-background correlation. This cannot be accomplished by the power spectrum with the normalization by an overall mean transmission. Applying this analysis to a real data set of Q1700+642 Lyα forest, we demonstrate that the proposed power spectrum estimator can perform correct normalization and effectively reveal the correlation between the fluctuations and background of the transmitted flux on small scales. Therefore, the self-normalized power spectrum would be useful for the discrimination among models without the uncertainties caused by free (or fitting) parameters.
Within-person associations between racial microaggressions and sleep among African American and Latinx young adults.

Emerging work suggests that experiences of racial discrimination may impact overall sleep health; however, there is limited work on the link between racial microaggressions and sleep. Using weekly diary data, the current study examined young adults' weekly reports of racial microaggressions across 4 weeks, and their relation to weekly reports of sleep-onset latency, reduced total sleep time and poorer sleep quality. This design allowed us to examine how within-person fluctuations in racial microaggressions corresponded with young adults' sleep. Data were collected among 140 African American (62.1%) and Latinx (37.9%) college students attending a Midwestern University. Students were randomly selected to participate; they were, on average, 20.70 years old (SD = 1.22) and the majority were female (69.3%). Participants self-reported their racial microaggressions and sleep behaviours (i.e. sleep-onset latency, total sleep time and sleep quality) each week (across 4 weeks). Multilevel modelling showed significant within-person effects of racial microaggressions for sleep onset and sleep quality, but not for total sleep duration. Specifically, on weeks that individuals reported increases in racial microaggressions, they reported greater sleep-onset duration and poorer sleep quality. The current findings provide preliminary evidence that racial microaggressions are associated with sleep-onset durations and sleep quality among African American and Latinx young adults. Although racial microaggressions are often considered subtle, they may impact the sleep health of young adults in marginalized groups.
Route optimization for energy efficient airport shuttle operations – A case study from Dallas Fort worth International Airport

Abstract The objective of this research is to reduce energy consumption from intra airport shuttle operations by optimizing routes and schedules, without compromising on passenger travel experience. To achieve this objective, we propose an optimization model that generates optimal airport shuttle routes for a given set of constraints and a discrete-event simulator that evaluates the optimal shuttle routes in a stochastic environment to understand the tradeoffs between the amount of time passengers wait for shuttles, and shuttle energy consumption. The proposed optimization model and stochastic simulation are tested using shuttle route data provided by the Dallas Fort Worth International Airport. Results indicate that optimized routes can lead to a 20% energy reduction in shuttle operations with a modest 2-min increase in average shuttle wait times. The optimization model and simulator presented here are designed to be generalizable and can be adapted to optimize shuttle operations at any major airport.
Variation in diet and activity of river otters (Lontra canadensis) by season and aquatic community

Keystone predators can impact many prey species, including those that are endangered. A requisite to assess the impact predators have on different prey populations is to identify the species being consumed in different types of communities, while accounting for possible seasonal variation in consumption. Here we used analysis of North American river otter (Lontra canadensis) scat to assess the impact river otters have on their prey populations, particularly endangered salmonids and migrating birds. We analyzed the prey composition of 1,411 river otter scats collected from 10 sites in Humboldt County, California, between 2011 and 2012. Analysis of prey items in scat placed study sites into four distinct clusters based on diet. Fish, mostly from the families Gasterosteidae, Cottidae, and Pholidae, formed the primary prey component, and crustaceans, birds, amphibians, and insects, also were important components of river otter diet. Salmonids constituted < 5% of overall diet, but river otters consumed the largest percentage of salmon during salmon spawning season at the inland cluster where salmonids spawn. Scat marking intensity varied between clusters and seasons, with the most scats collected in the autumn and the fewest in the winter/spring, except at the inland cluster where the pattern of marking activity was reversed. River otters may be responding to seasonal migrations of endangered and threatened salmonids. Diet surveys of this type are useful for monitoring resource use by top predators in aquatic ecosystems.
EEG findings in CART T associated neurotoxicity: clinical and radiological correlations.

BACKGROUND While EEG is frequently reported as abnormal after CAR T cell therapy, its clinical significance remains unclear. We aim to systematically describe EEG features in a large single-center cohort and correlate them with clinical and radiological findings. METHODS We retrospectively identified patients undergoing CAR T cell therapy who had continuous EEG. Neurotoxicity grades, detailed neurological symptoms, and brain MRI or FDG-PET were obtained. Correlation between clinical and radiological findings and EEG features was assessed. RESULTS In 81 patients with median neurotoxicity grade 3 (IQR 2-3), diffuse EEG background slowing was the most common finding and correlated with neurotoxicity severity (p <0.001). A total of 42 patients had rhythmic or periodic patterns, 16 of them within the ictal-interictal-continuum (IIC), 5 with clinical seizures, and 3 with only electrographic seizures. Focal EEG abnormalities, consisting of lateralized periodic discharges (LPD, n=1), lateralized rhythmic delta activity (LRDA, n=6), or focal slowing (n=19), were found in 22 patients. All patients with LRDA, LPD, and 10/19 patients with focal slowing had focal clinical symptoms concordant with these EEG abnormalities. In addition, these focal EEG changes often correlated with PET hypometabolism or MRI hypoperfusion, in absence of a structural lesion. CONCLUSION In adult patients experiencing neurotoxicity after CAR T cell infusion, EEG degree of background disorganization correlated with neurotoxicity severity. IIC patterns and focal EEG abnormalities are frequent and often correlate with focal clinical symptoms and with PET-hypometabolism/MRI-hypoperfusion, without structural lesion. The etiology of these findings remains to be elucidated.
Ca2+ kickstarts antiviral RNAi.

RNAi is a major plant antiviral strategy. However, the mechanisms triggering RNAi are unknown. In this issue of Cell Host & Microbe, Wang et al. (2021) demonstrate that wound-induced calcium signaling induces RNAi activation. As a counter-defense, a viral suppressor of RNAi (VSR) interferes with players in calcium signaling.
Team Relationships and Performance: Evidence from Healthcare Referral Networks

We examine the teams that emerge when a primary care physician (PCP) refers patients to specialists. When PCPs concentrate their specialist referrals—for instance, by sending their cardiology patie...
Bernoulli Numbers and Polynomials

The oldest distribution is that defined by the Bernoulli polynomials, although of course their classical recurrence property was not called by that name.
Valuing Patterns and the Continuing Emergence of Eurocentric Science

So far we have examined some of the questions and experimental explorations of classical theoretical claims, such as the nature of motion, and how some notions of atoms or corpuscles and vacuums, provided space for scholars to begin to critically examine the claims embedded in an Aristotelian worldview. At the same time some Europeans, especially Portuguese explorers under the support of Prince Henry the Navigator, had begun a process of discovery that later was to involve other European countries including Spain, France, Holland, and England seeking to expand their spheres of influence across the Earth. The extent of European memory about the structure and extent of the Earth and its continents and oceans can be noted in the image of Ptolemy’s map from his book, Geographia (First published about 150 CE), which was an attempt to record the extent of Roman knowledge of the world in the second century.
The frequency of anovulatory menstruation as determined by endometrial biopsy

Abstract 1. 1. Two hundred and sixty-one endometrial biopsies were taken the last one-third of the menstrual cycle from 103 patients in a mental hospital. 2. 2. Fourteen anovulatory cycles were found in 9 patients. Two patients showed successive anovulatory cycles; seven patients showed both anovulatory and ovulatory cycles. 3. 3. Parity was not found to be a factor, but women past 40 years of age were seen to show a higher incidence of anovulatory menstruation—7.69 per cent as compared to 10.52 per cent. 4. 4. In this group of patients the incidence of anovulatory cycles was 5.36 per cent. The patient incidence was 8.7 per cent. 5. 5. While all the women in this group are psychotic patients, the incidence of anovulatory menstruation in them compares quite closely with that found in normal, healthy women.
Further Results on the Deposition of Cohesive Sediments

Experimental investigations on the depositional behavior of suspensions of fine cohesive sediments in turbulent flows have been conducted in a special laboratory apparatus. This apparatus consists essentially of an annular channel containing the water-sediment mixture, and an annular ring positioned within the channel and in contact with the water surface. A turbulent shear flow is generated by a simultaneous rotation of the channel and ring in opposite directions at the proper relative speeds to minimize secondary currents in the bottom of the channel, so that the sediment deposits uniformly.
Cost of Equity Uncertainty and Rate of Return Regulation: Implications of New Developments in Financial Economics

Estimation of a corporation's cost of equity is crucial for various financial analyses. One area in which it is necessary is in rate of return regulation. In order for the regulator to set an appropriate rate of return, the corporation's cost of equity must be estimated accurately. This article examines the two most common methods used to estimate the cost of equity: the discounted dividend model and the capital asset pricing model. Recent developments in financial economics make traditional applications of these methods suspect. These developments are the use of share repurchases, and a prospective equity risk premium much lower than historic values suggest. The uncertainty described here, in combination with previously known sources of uncertainty, suggest that increased scrutiny of cost of equity estimates is warranted. Also, the ongoing search for improved models of the cost of equity should continue.
Hepatic drug-metabolizing enzyme activity in rats pretreated with (−)-emetine or (±)-2,3-dehydroemetine

1. Pretreatment of female rats with (−)-emetine or (±)-2,3-dehydroemetine (at 18μmol/kg body wt. for 24h) prolongs the hexobarbital-induced sleeping-time of the treated animals. 2. This effect is not observed on pretreating animals with other compounds closely related to (−)-emetine, such as (−)-isoemetine or (+)- O -methylpsychotrine. 3. Liver microsomal drug-metabolizing enzyme activity in vitro as measured by N -demethylation of aminopyrine and azo-reduction of Neoprontosil is inhibited in rats pretreated with (−)-emetine or with (±)-2,3-dehydroemetine. 4. These inhibitory effects on drug metabolism in vitro are not observed in corresponding experiments involving pretreatment of rats with (−)-isoemetine or (+)- O -methylpsychotrine. 5. Co-administration of emetine or 2,3-dehydroemetine and sodium phenobarbital or 1,1-dichloro-2- o -chlorophenyl-2- p -chlorophenylethane to rats abolishes or greatly diminishes the stimulation of drug-metabolizing enzyme activity in vitro usually obtained by the administration of phenobarbital or 1,1-dichloro-2- o -chlorophenyl-2- p -chlorophenylethane alone. 6. Further, in rats pretreated with sodium phenobarbital and subsequently injected with emetine or 2,3-dehydroemetine the pre-stimulated drug-metabolizing enzyme activity in vitro is diminished. 7. The inhibitory effects on drug-metabolizing enzyme activity after pretreatment with (−)-emetine or (±)-2,3-dehydroemetine do not appear to be related to NADPH generation.
Supracervical hysterectomy versus total abdominal hysterectomy: perceived effects on sexual function

Our investigation sought to compare changes in sexual function following supracervical hysterectomy (SCH) and total abdominal hysterectomy (TAH). A retrospective chart review was performed to identify all patients who underwent supracervical hysterectomy or total abdominal hysterectomy at a tertiary care center. Patients who met criteria for participation were sent a one page confidential, anonymous questionnaire to assess sexual function experienced both pre- and postoperatively. A total of 69 patients in each group were eligible for participation. A multiple logistic regression model was used to analyze measured variables. Forty-eight percent (n = 33) of women undergoing a SCH returned the questionnaire, while 39% (n = 27) of those undergoing a TAH chose to participate. There were no significant demographic differences between the two groups. Patients who underwent TAH reported worse postoperative sexual outcome than SCH patients with respect to intercourse frequency, orgasm frequency and overall sexual satisfaction (P = 0.01, 0.03, and 0.03, respectively). Irrespective of type of hysterectomy, 35% of patients who underwent bilateral salpingoophorectomy (BSO) with hysterectomy experienced worse overall sexual satisfaction compared to 3% of patients who underwent hysterectomy alone (P = 0.02). Our data suggest that TAH patients experienced worse postoperative sexual function than SCH patients with respect to intercourse frequency and overall sexual satisfaction. Irrespective of type of hysterectomy, patients who underwent bilateral salpingoophorectomy experienced worse overall sexual satisfaction.
Morphogenetic movements and multicellular development in the fruiting Myxobacterium, Stigmatella aurantiaca.

Abstract Stigmatella aurantiaca, strain DW-4, is a bacterium that grows as single cells in liquid culture but will synchronously aggregate and construct multicellular fruiting bodies when starved on an agar surface. The fruiting body consists of a stalk and several sporangia housing differentiated myxospores. Fruiting body development is stimulated by exposure of the aggregating cells to incandescent light.
Dilation of the vaginal cuff using the Bakri Postpartum Balloon to extract the large uterus at the time of robotic hysterectomy for endometrial carcinoma

Removal of large uterine specimens during robotic or total laparoscopic hysterectomy poses surgical challenges, particularly in cases performed for gynecologic malignancy. A 23-year-old patient with endometrioid adenocarcinoma of the endometrium underwent robotic total laparoscopic hysterectomy with bilateral salpingo-oophorectomy. The large uterine specimen was removed by dilating the colpotomy incision using the Bakri Postpartum Balloon™. Dilation of the colpotomy incision with the uterine tamponade balloon can allow for the intact removal of a large uterine specimen in cases of robotic or total laparoscopic hysterectomy performed for gynecologic malignancy when specimen morcellation is contraindicated.
An antiserum (ES1) against a particulate form of extracellular matrix blocks the transition of cardiac endothelium into mesenchyme in culture.

The epithelial-mesenchymal transition of cardiac endothelium is a critical developmental event in the formation of valvular and septal anlagen. We have demonstrated previously that this event can be mimicked in culture by treating atrioventricular canal (AV) endothelium with EDTA-soluble proteins extracted from embryonic heart tissue. This activity was fractionated by ultracentrifugation of the EDTA extract, indicating that the critical proteins existed as a multicomponent complex. Based on these results we propose that: (1) the in vitro particulates in EDTA extracts correspond to an observed particulate form of extracellular matrix within the myocardial basement membrane (MBM) of mesenchyme-forming regions and (2) one or more of the proteins in the MBM particulates function to elicit the epithelial-mesenchymal transition. To test these hypotheses we utilized an antiserum, termed ES1, prepared against EDTA-extractable particulates from embryonic chick hearts. Both ES1 and an anti-fibronectin monoclonal antibody (M3H) co-localized in situ to particles within the MBM; however, no ES1 reactivity towards fibronectin could be detected by ELISA or immunoblot analysis. The ES1-positive MBM particulates were removed by extraction with EDTA, but not with PBS, indicating a divalent cation-mediated association of the constituent proteins. ES1 antibodies recognized two major (28 and 46 kDa) and three minor (93, 109, and 180 kDa) proteins on immunoblots of EDTA-extractable proteins. When tested in culture, ES1 antiserum inhibited the formation of mesenchyme from AV endothelium in a dose-dependent manner, while M3H did not. These results are consistent with an active role for one or more of the ES1 antigens in initiating the formation of AV mesenchyme. The localization of ES1 antigens to the extracellular matrix at other dynamic interfaces, e.g., ectoderm/neural tube and limb bud ectoderm/mesoderm, point to a potentially general importance of ES1 antigens in mediating similar developmental interactions.
Some Physical Properties of Weathered Wool1

The deterioration from outdoor weathering of experimental wool fabrics differing in fiber fineness was measured by breaking strength, elongation at break, and crease recovery. With the amount of solar energy held approximately constant for each sampling period of each of the three consecutive sets of exposures, ambient temperature seemed to control the rate of deterioration.Differences in strength and elongation among the fabrics were non-significant. The fine wools recovered from creasing significantly more than the medium wool.
Peroxynitrite inhibits myofibrillar protein function in an in vitro assay of motility

Abstract We determined the effects of peroxynitrite (ONOO−) on cardiac myosin, actin, and thin filaments in order to more clearly understand the impact of this reactive compound in ischemia/reperfusion injury and heart failure. Actin filaments, native thin filaments, and α-cardiac myosin from rat hearts were exposed to ONOO− in the presence of 2 mM bicarbonate. Filament velocities over myosin, calcium sensitivity, and relative force generated by myosin were assessed in an in vitro motility assay in the absence of reducing agents. ONOO− concentrations ≥ 10 μM significantly reduced the velocities of thin filaments or bare actin filaments over α-cardiac myosin when any of these proteins were exposed individually. These functional deficits were linearly related to the degree of tyrosine nitration, with myosin being the most sensitive. However, at 10 μM ONOO− the calcium sensitivity of thin filaments remained unchanged. Cotreatment of myosin and thin filaments, analogous to the in vivo situation, resulted in a significantly greater functional deficit. The load supported by myosin after ONOO− exposure was estimated using mixtures experiments to be increased threefold. These data suggest that nitration of myofibrillar proteins can contribute to cardiac contractile dysfunction in pathologic states in which ONOO− is liberated.
Simple summation rule for optimal fixation selection in visual search

When searching for a known target in a natural texture, practiced humans achieve near-optimal performance compared to a Bayesian ideal searcher constrained with the human map of target detectability across the visual field [Najemnik, J., & Geisler, W. S. (2005). Optimal eye movement strategies in visual search. Nature, 434, 387–391]. To do so, humans must be good at choosing where to fixate during the search [Najemnik, J., & Geisler, W.S. (2008). Eye movement statistics in humans are consistent with an optimal strategy. Journal of Vision, 8(3), 1–14. 4]; however, it seems unlikely that a biological nervous system would implement the computations for the Bayesian ideal fixation selection because of their complexity. Here we derive and test a simple heuristic for optimal fixation selection that appears to be a much better candidate for implementation within a biological nervous system. Specifically, we show that the near-optimal fixation location is the maximum of the current posterior probability distribution for target location after the distribution is filtered by (convolved with) the square of the retinotopic target detectability map. We term the model that uses this strategy the entropy limit minimization (ELM) searcher. We show that when constrained with human-like retinotopic map of target detectability and human search error rates, the ELM searcher performs as well as the Bayesian ideal searcher, and produces fixation statistics similar to human. 2009 Published by Elsevier Ltd.
Skeletal development in Acropora palmata (Lamarck 1816): a scanning electron microscope (SEM) comparison demonstrating similar mechanisms of skeletal extension in axial versus encrusting growth

Many Acropora palmata colonies consist of an encrusting basal portion and erect branches. Linear growth of the skeleton results in extension along the substrate (encrusting growth), lengthening of branches (axial growth) and thickening of branches and crust (radial growth). Scanning Electron Microscopy is used to compare the mechanisms of skeletal extension between encrusting growth and axial growth. In encrusting growth, the distal margin of the skeleton lacks corallites (which develop about 1 mm from the edge); in contrast, in axial growth, axial corallites along the branch tip form the distal portion of the skeleton. In both locations, the distal margin of the skeleton consists of a lattice-like structure composed of rods that extend from the body of the skeleton and bars that connect these rods. An actively extending skeleton is characterized by sharply pointed rods and partially developed bars. Distal growth of rods (and formation of bars) is effected by the formation of new sclerodermites. Each sclerodermite begins with the deposition of fusiform crystals (that range in length from 1 to 5 μm). These provide a surface for nucleation and growth of spherulitic tufts, clusters of short (<1 μm long) aragonite needles. The needles that are oriented perpendicular to the axis of the skeletal element (rod or bar), and perpendicular to the overlying calicoblastic epithelium, continue extension to appear on the surface of the skeleton as 10–15 μm wide bundles (of needle tips) called fasciculi. However, some crusts that abut competitors for space have a different morphology of skeletal elements (rods and bars). The distal edge of these crusts terminates in blunt coalescing rods, and bars that are fully formed. Absence of fusiform crystals, lack of sharply pointed rods and bars, and full development of sclerodermites characterize a skeletal region that has ceased, perhaps only temporarily, skeletal extension.
Permanent Wear of Soft Contact Lenses in Aphakic Eyes

In a five-year study, permanent wear of soft contact lenses was achieved by selecting patients and lenses properly, and offered a viable and probably safer alternative to intraocular lenses. Twenty-five of these 49 patients wore their initial lens or a similar lens continuously for over three years. A visual acuity of 6/12 (20/40) or better was obtained in 45 (91.8%) patients. Four (8%) had ocular problems not related to contact lenses that precluded the same improvement in central vision. The most common complications were reversible epithelial edema, superficial vascularization, and conjunctivitis. There was a strong correlation between edema and superficial vascularization in eyes fitted with lenses having a poorly made inside bevel. Calcium deposits were the most frequently found spot on permanent-wear soft contact lenses (nine eyes, 18%).
Cardiovascular aging and anesthetic implications

HE MEDICAL CARE of an aging population represents an almost overwhelming challenge to the US medical system. Currently, 12.4% of the population is over 65; by 2020, the value is expected to climb to 16.5%. When coupled with the expected 15% increase in the US population, this figure should represent 54 million people, a greater than 50% increase from the 35 million in 2000 (Bureau of the Census, www.census. gov). 1 Older patients have invasive procedures at almost 4 times the frequency of people under 65 (CDC National Center for Health Statistics, www.cdc.gov/nchs/data/ad/ad319.pdf and www.cdc.gov/nchs/data/ad/ad300.pdf).2 They also suffer complications more frequently and require longer hospitalization on average.1 In 1999, patients over 65 accounted for 48% of all inpatient hospital days (CDC National Center for Health Statistics, www.cdc.gov/nchs/data/ad/ad319.pdf and www.cdc. gov/nchs/data/ad/ad300.pdf). Without question, great strides have been made at reducing medical costs in the past decade. The shift to outpatient surgery or at least morning admission and more extensive use of laparoscopic surgery are obvious examples. With health care dollars becoming increasingly tight, it is in the public’s best interest to use those dollars as effectively as possible and to continue to find ways to reduce the incidence of perioperative complications. Perioperative morbidity and mortality are functions of the disease that leads to the surgery, the patient’s comorbid disease, the severity of the surgery, and the reduction in physiologic reserve that accompanies aging. Of age and comorbid disease, which is more important? In univariate analysis, age is a strong correlate of risk, with each decade of age increasing risk by a factor of approximately 1.75.2 Studies that involve multivariate analysis occasionally fail to include age, but in most studies age remains an independent risk factor. The Veterans Affairs, in their National Surgical Quality Improvement Program and their Continuous Improvement in Cardiac Surgery Program, have identified a number of risk factors that are used to calculate expected mortality. For noncardiac surgery, 30-day mortality is
Instabilities in uranium plasma.

The nonlinear evolution of unstable sound waves in a uranium plasma has been calculated using a multiple time-scale asymptotic expansion scheme. The fluid equations used include the fission power density, radiation diffusion, and the effects of the changing degree of ionization of the uranium atoms. The nonlinear growth of unstable waves is shown to be limited by mode coupling to shorter wavelength waves which are damped by radiation diffusion. This mechanism limits the wave pressure fluctuations to values of order delta P/P equal to about .00001 in the plasma of a typical gas-core nuclear rocket engine. The instability is thus not expected to present a control problem for this engine.
Effect of strain in Si/SiGe modulation-doped quantum wells

Abstract A novel technique has been devised to allow the growth of strained Si/SiGe quantum wells (QW's) on Si substrates, while virtually eliminating threading dislocations. The amount of strain in the quantum wells is tuned by ramping the Ge content in a Si/SiGe multilayer buffer. Both n-type and p-type modulation-doped structures have been grown using this technique, with mobilities at 1.4 K as high as 19 000 cm 2 /V s and 6000 cm 2 /V s, respectively. The effect of strain on the bandstructure in both cases is investigated.
The local monoaminergic dependency of spinal ketamine.

The effects of s.c. doses of naloxone, methysergide and phentolamine on ketamine-induced spinal analgesia were assessed to determine the involvement of opiate, serotonergic and noradrenergic components mediating ketamine's antinociceptive action. Ketamine administered intrathecally (i.t.) produced a significant elevation in tail-flick latency in rats. The spinal antinociceptive effects of ketamine were dose dependently reversed by methysergide (ID50 = 0.008 mg/kg s.c.), phentolamine (ID50 = 0.88 mg/kg s.c.) and naloxone (ID50 = 3.0 mg/kg s.c.). Unlike morphine, which remains analgesic and dependent on opiate interactions following bilateral lesions of the dorsolateral funiculus (DLF), ketamine analgesia was absent following DLF lesions. Thus, ketamine appears to produce an antinociceptive response which is dependent upon the neuronal activity of the descending pain-inhibitory pathways. The monoaminergic components comprising the descending pathways appear to be more prominent in the action of ketamine than they are in the spinal action of morphine. Furthermore, the spinal opioid receptors involved in ketamine's effect may be different from the mu subtype preferred by morphine.
Waves in an elastic plate with an irregular boundary

Investigated is the effect of a surface irregularity on the propagation of waves in an isotropic, elastic plate, the method of perturbation being employed to determine the scattered field to the first order in a small parameter descriptive of the height of the irregularity. While the firstorder displacement field in the region under, and in the immediate vicinity of, the disturbed surface is very complicated, the far field in either direction, generated by either a symmetric or an antisymmetric incident wave, consists of a finite number of propagating waves, symmetric and antisymmetric, their number corresponding to the number of real roots of the frequency equation for the given frequency of incident wave.
Effects of dopamine receptor antagonists on the acquisition of ethanol-induced conditioned place preference in mice

Rationale Studies support differential roles of dopamine receptor subfamilies in the rewarding and reinforcing properties of drugs of abuse, including ethanol. However, the roles these receptor subfamilies play in ethanol reward are not fully delineated.
Dispensed Selective and Nonselective Nonsteroidal Anti-inflammatory Drugs and the Risk of Moderate to Severe Hyperkalemia: A Nested Case-Control Study

Background It is not known whether nonselective and cyclooxygenase 2 (COX-2) selective nonsteroidal anti-inflammatory drugs (NSAIDs) differ in terms of hyperkalemia risk. The aim of this study was to compare the differential risk of hyperkalemia associated with various NSAIDs. Study Design Nested case-control study. Setting & Participants New NSAID users receiving care in the US Department of Veterans Affairs (VA) health care system from October 2000 to September 2006. Predictor of Factor Different NSAIDs ordered by COX-2 selectivity. Outcomes & Measurements Risk of hyperkalemia (defined as first serum potassium value ≥6.0 mEq/L) was estimated with a multivariate conditional logistic model adjusting for age, race, morbidities, medications, and contrast media. Results We identified 18,326 cases of hyperkalemia and 355,106 matched controls. Risk of hyperkalemia did not differ in patients using a single NSAID (adjusted OR, 1.03; 95% CI, 0.98-1.08) or 2 or more NSAIDs (OR, 1.16; 95% CI, 0.96-1.41) compared with patients no longer using an NSAID. However, risk varied by specific NSAID and elevated risks were found for use of rofecoxib, celecoxib, diclofenac, and indomethacin, but not meloxicam, etodolac, piroxicam, sulindac, ibuprofen, naproxen, and ketorolac. Interactions were found between NSAID use and exposure to renin-angiotensin blockers and contrast media. Limitations Some NSAIDs are available over the counter and women are under-represented in the VA population. Conclusions NSAIDs may not by themselves carry a higher risk of moderate to severe hyperkalemia. Certain NSAIDs may increase the risk of hyperkalemia, but it is not related to COX-2 selectivity of the NSAID and may depend on concurrent exposure to other agents.
Structural basis for O2 sensing by the hemerythrin-like domain of a bacterial chemotaxis protein: substrate tunnel and fluxional N terminus.

The methyl-accepting chemotaxis protein, DcrH, from the anaerobic sulfate-reducing bacterium, Desulfovibrio vulgaris (Hildenborough), has a hemerythrin-like domain, DcrH-Hr, at its C terminus. DcrH-Hr was previously shown to contain a diiron site that binds O2, suggesting an O2-sensing function. X-ray crystal structures of diferric (met-), azido-diferric (azidomet-), and diferrous (deoxy-) DcrH-Hr reveal a “substrate tunnel” distinct from that in invertebrate hemerythrins. This tunnel is proposed to facilitate the rapid autoxidation of oxy-DcrH-Hr and suggests that sensing is triggered by O2 binding and subsequent oxidation of the diferrous active site. The N-terminal loop of DcrH-Hr is highly ordered in both met- and azidomet-DcrH-Hr but is disordered in deoxy-DcrH-Hr. These redox-dependent conformational differences presumably transduce the sensory signal of DcrH-Hr to the neighboring methylation domain in the full-length receptor. Given the putative cytoplasmic localization of its Hr-like O2-sensing do...
Modifications of carcinogen metabolism in hepatic microsomes of suckling young by 3-methylcholanthrene or β-naphthoflavone administered to lactating rats

Abstract The effects of treating lactating rats with 3-methylcholanthrene (3-MC) or β-naphthoflavone (β-NF) (three i.p. injections of 20 or 40 mg compound/kg of body weight) on hepatic microsomal enzymes of their suckling young were examined. This treatment had no apparent effect on the contents of cytochromes P-450 and b 5 or on the activities of NADH- and NADPH-cytochrome c reductases in hepatic microsomes of the pups. However, these microsomes had 8- and 6-fold increased capacities for hydroxylations of benzo[ a ]pyrene (B[ a ]P) and N-2-fluorenylacetamide (2-FAA) respectively. These increases were about 5-fold greater in the hepatic microsomes of the dams, in which they were inhibited by 0.1 mM α-naphthoflavone (α-NF) invitro 72–81 and 89–95% and by 0.1 mM β-NF in vitro 12–41 and 60–76% respectively. In the pups, the induced activities were also inhibited, whereas the basal hydroxylations of B[ a ]P and 2-FAA were stimulated by α-NF 2.7- and 5.0-fold and by β-NF 1.4- and 2.4-fold respectively. The inhibition of the induced hydroxylations by α-NF and β-NF may be explained by their higher affinities ( K s , 0.14 and 0.28 μM, respectively) than those of B[ a ]P and 2-FAA ( K s 4.4 to 8.8 and 2.4 to 3.1 μM, respectively) for cytochrome P-450. Whereas β-NF gave a type I binding spectrum, α-NF gave a spectrum composed of type I and reverse-type I elements. Analysis of metabolites of 2-FAA showed differences in their type and amounts formed by hepatic microsomes of β-NF-treated lactating rats and their pups. Thus, in the dams the formation of 1-, 3-, 5-, 7-, 9- and N-hydroxy-2-FAA was increased by 9-, 30-, 40-, 5-, 20- and 5-fold respectively. In the pups, the formation of 1-, 3-, 5-, 7- and N-hydroxy-2-FAA was increased by 2-, 30-, 18-, 4- and 27-fold respectively. All these increased hydroxylations were inhibited by 0.1 mM α-NF in vitro . In the hepatic microsomes of pups from the corn oil-treated dams, α-NF stimulated all ring-hydroxylations, but not N-hydroxylation of 2-FAA. The results support earlier findings that microsomal enzymes differ in immature and mature rat liver and suggest that N-hydroxylation of 2-FAA, the activation required for carcinogenesis, and specific ring-hydroxylations are catalyzed by different cytochrome P-450 isozymes. Our studies showed that 3-MC and β-NF and/or their metabolites were transferred with milk of dams to their suckling pups in which they modified metabolism of carcinogens.
Retrieval in cued recall

Three experiments examined retrieval in a cued recall paradigm by manipulating the pattern of output cues. In the first two experiments, subjects were paced through recall of a categorized list by recalling one word at a time in response to a category name as a retrieval cue. The pattern of these output cues exerted a strong influence on performance. Subjects recalled considerably more when the cues were blocked by category than when required to recall successive words from different categories. This output effect increased over trials, and was interpreted in terms of a model in which subjects develop a retrieval strategy that can be interfered with by the circumstances of output. The last experiment contrasted structural and strategy models in a hierarchical recall paradigm. Subjects were given a set of postinput recall cues that either made evident the hierarchical structure of the input list or contained the same cue words but with no hierarchical information. Information about the hierarchical structure improved performance even when provided only during recall. The data were discuss in terms of recent models of recall, and a compromise was suggested.
Local Buckling Tests on Cold-Formed Steel Beams

\iC and \iZ sections are two of the most common cold-formed steel shapes in use today. Accurate prediction of the bending performance of these sections is important for reliable and efficient cold-formed steel structures. Recent analytical work has highlighted discontinuities and inconsistencies in the American Iron and Steel Institute (AISI) and Canadian Standards Association (S136) design provisions for stiffened elements under a stress gradient (i.e., the web of \iC or \iZ sections). New methods have been proposed for design, and an interim method has been adopted in the North American Specification (NAS). However, existing tests on \iC and \iZ sections do not provide a definitive evaluation of the design expressions, due primarily to incomplete restriction of the distortional buckling mode. Described in this paper is a series of flexural tests with details selected specifically to insure that local buckling is free to form, but distortional buckling and lateral-torsional buckling are restricted. The members selected for the tests provide systematic variation in the web slenderness (\Ih/t\N) while varying other relevant nondimensional parameters (i.e., \Ih/b, b/t, d/t, d/b\N). Initial analysis of the completed testing indicates that overall test-to-predicted ratios for AISI, S136, NAS, and the direct strength method are all adequate, but systematic differences are observed.
Glutathione disulphide as a marker of reperfusion injury in ischaemic skin flaps

Estimation of the oxidised form of glutathione (GSSG) in an ischaemic/reperfused organ is frequently employed as an indicator of oxidative stress created by the production of oxygen free radicals during the reperfusion period. The time course of oxidative stress and tissue damage in 19 ischaemic/reperfused guinea-pig island skin flaps was evaluated. No-flow ischaemia was induced in the flaps for 6 h in 7 animals, and for 8 h in 9 animals (a further 3 animals served as controls without ischaemia). Arterial and venous blood samples were obtained directly from the flap pedicle at baseline, 10, 30, and 60 min following reperfusion. Results suggest that a second focus of oxidative injury, possibly mediated by activated neutrophils, contributes to the overall process of reperfusion injury. Plasma levels of GSSG allow for a more sensitive quantification of oxidant stress within reperfused ischaemic flaps, and may serve as a useful tool in skin flap research.
Continuous autoanalysis of glycopeptides and glycoproteins.

Abstract The Technicon AutoAnalyzer has been adapted for continuous carbohydrate analysis of column effluents using the phenol-sulfuric acid procedure. It is possible to determine quantitatively the amount of carbohydrate present by comparison with an appropriate standard curve. When used in conjunction with the conventional peptide analyzer, the method is of great utility in the chromatographic analysis of glyco-peptides.