cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract PO-014: Harnessing the heterogeneity of circulating hybrid cells in pancreatic adenocarcinoma

Pancreatic adenocarcinoma (PDAC) remains one of the most lethal malignancies in the United States and tumor heterogeneity has major implications on the effectiveness of systemic therapies. Comprehensive tumor analysis at the single cell level offers an in-depth examination of neoplastic cells with metastatic potential and supports development of individualized treatment strategies to ultimately improve survival. Hybrid cells are a novel cell population derived from immune-cancer cell fusion within solid tumors and disseminate into peripheral blood, where they can be detected as circulating hybrid cells (CHCs) based on their dual expression of tumor and immune cell epitopes. Compared to conventionally-defined circulating tumor cells (CTCs), CHCs are found in patients at higher levels which allows for more robust phenotypic analyses of tumor cell features and collection for downstream multi-omic profiling. To investigate heterogeneity among disseminated CHCs in patients with PDAC, we assessed for tumor cell features using immunohistochemical analyses of single cells from peripheral blood mononuclear cell smears and by single cell RNA sequencing (scRNA-seq) from FACS-isolated cells. Downstream image analyses was performed Zeiss Zen blue software and scRNA-seq was analyzed using the Seurat analysis package. We determined that PDAC patients harbored heterogeneous populations of CHCs with differential protein expression that mirrored expression in corresponding primary tumors. Further, scRNA-seq analyses identified CHC populations with varying degrees of retained tumor identity, as well as subsets derived from different immune cell lineages. Unsupervised clustering of CHCs with tumor-dominate phenotypes demonstrated high differential expression of cancer related genes with known implications in PDAC tumors and treatment resistant pathways. Inference copy number variation analysis revealed chromosomal amplifications of 1q and 19q along with deletions of 6p, 12q, and 22q, characteristic of PDAC tumors. Additionally, a myriad of KRAS mutations were identified in patient CHCs but absent in normal leukocytes. As the product of tumor and immune cell fusion, CHCs provide a rich source for assessing PDAC heterogeneity through genetic and protein expression analyses. Ultimately, CHCs have great potential as a liquid biopsy in pancreatic cancer which could be harnessed to guide therapy. Citation Format: Brett Scott Walker, Sidharth Sengupta, Michael Parappilly, Aysegul Ors, Jared Fischer, Thomas Sutton, Brett Sheppard, Skye Mayo, Melissa Wong. Harnessing the heterogeneity of circulating hybrid cells in pancreatic adenocarcinoma [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-014.
Preservice teachers’ knowledge about bullying: implications for teacher education

Schools are placing a heavy focus on providing a safe learning environment. Part of that safe environment is for the school to be a bully-free zone. In order for a school to be bully-free, staff mu...
Spectrophotometric determination of the bicarbonate dissociation constant in seawater

Abstract The aqueous carbon dioxide (CO2) system stoichiometric dissociation constants K1 and K2 express the relative concentrations of CO2, HCO3− (bicarbonate), and CO32− (carbonate) in terms of pH. These constants are critical in the study of seawater and the oceans because any mathematical expression that relates the four major CO2 system parameters (pH, here expressed on the total hydrogen ion concentration scale, pHT; total dissolved inorganic carbon, CT; total alkalinity, AT; and CO2 fugacity, fCO2) requires the use of K1 and K2. Uncertainties associated with current characterizations of pK1 and pK2 (where pK = −log K), on the order of 0.01 and 0.02, limit the accuracy of marine CO2 system calculations. This work reports the results of a spectrophotometric method to experimentally determine the product K1K2 over environmentally relevant ranges of temperature (288.15 ≤ T ≤ 308.15 K) and salinity (19.6 ≤ Sp ≤ 41) where Sp denotes the practical salinity scale. Using previously published parameterizations of K1, values of pK2 could then be calculated from the new K1K2 values. The resulting set of pK2 values was fitted as a function of Sp and T to obtain a new pK2 parameterization (denoted as SWpK2) calculated with the K1 of Waters and Millero (2013) as revised by Waters et al. (2014): SWpK2 = 116.8067 − 3655.02 T −1 − 16.45817 ln T + 0.04523 Sp − 0.615 Sp0.5 − 0.0002799 Sp2 + 4.969 (Sp/T) The average root mean square deviation between the equation and the observed data is 0.003. Residuals of this pK2 fitting function (i.e., measured pK2 minus parameterized pK2) are substantially smaller than the residuals obtained in previous works. Similarly, the total standard uncertainty in pK2 is reduced from 0.015 (previous characterizations) to 0.010 (this work). Internal consistency assessments (comparisons of measured versus calculated values of AT, CT, pHT, and fCO2) were used to evaluate the computational utility of the new K2 parameterization. Assessments from both laboratory and shipboard data indicate that the internal consistency of CO2 system calculations is improved using the K2 parameterization of this work. This new K2 parameterization provides the most precise, and potentially the most accurate, bicarbonate dissociation constant characterization presently available for open ocean conditions.
Increasing scholarly productivity: Developing an in-house academic librarian support network

Abstract Organizational and professional support structures can provide tools and resources to help academic librarians address the challenges of research and publishing. At the USF Libraries, a Research and Publishing committee was created by the faculty to develop tools and provide professional development support, with the aim of encouraging a community culture of research. The committee's work resulted in a series of workshops, discussion groups, guiding documents, and tools.
Heterotopic pancreas

Heterotopic pancreas will be encountered infrequently by the surgeon causing symptoms or incidentally atlaparotomy. To avoid confusion with carcinoma at laparotomy, local excision with frozen section diagnosis is recommended. Because frozen section diagnosis will not always be correct, clinical awareness of this condition at operation is also important.
Iron oxidation chemistry in ferritin. Increasing Fe/O2 stoichiometry during core formation.

Abstract The origin of previously observed variations in stoichiometry of iron oxidation during the oxidative deposition of iron in ferritin has been poorly understood. Knowledge of the stoichiometry of Fe(II) oxidation by O2 is essential to establishing the mechanism of iron core formation. In the present work, the amount of Fe(II) oxidized was measured by Mossbauer spectrometry and the O2 consumed by mass spectrometry. The number of protons produced in the reaction was measured by "pH stat" titration and hydrogen peroxide production by the effect of the enzyme catalase on the measured stoichiometry. For protein samples containing low levels of iron (24 Fe(II)/protein) the stoichiometry was found to be 1.95 +/- 0.18 Fe(II)/O2 with H2O2 being a product, viz. Equation 1. 2Fe2+ + O2 + 4H2O----2FeOOH + H2O2 + 4H+ (1) EPR spin trapping experiments showed no evidence of superoxide radical formation. The stoichiometry markedly increased with additional iron (240-960 Fe/protein), to a value of 4 Fe(II)/O2 as in Equation 2. 4Fe2+ + O2 + 6H2O----4FeOOH + 8H+ (2) As the iron core is progressively laid down, the mechanism of iron oxidation changes from a protein dominated process with H2O2 being the primary product of O2 reduction to a mineral surface dominated process where H2O is the primary product. These results emphasize the importance of the apoferritin shell in facilitating iron oxidation in the early stage of iron deposition prior to significant development of the polynuclear iron core.
Mean-field cluster model for the critical behaviour of ferromagnets.

Two separate theories are often used to characterize the paramagnetic properties of ferromagnetic materials. At temperatures T well above the Curie temperature, TC (where the transition from paramagnetic to ferromagnetic behaviour occurs), classical mean-field theory1 yields the Curie–Weiss law for the magnetic susceptibility: χ( T) ∝ 1/(T - Θ), where Θ is the Weiss constant. Close to TC, however, the standard mean-field approach breaks down so that better agreement with experimental data is provided by critical scaling theory2,3: χ(T) ∝ 1/(T - TC)γ, where γ is a scaling exponent. But there is no known model capable of predicting the measured values of γ nor its variation among different substances4. Here I use a mean-field cluster model5 based on finite-size thermostatistics6,7 to extend the range of mean-field theory, thereby eliminating the need for a separate scaling regime. The mean-field approximation is justified by using a kinetic-energy term to maintain the microcanonical ensemble8. The model reproduces the Curie–Weiss law at high temperatures, but the classical Weiss transition at TC = Θ is suppressed by finite-size effects. Instead, the fraction of clusters with a specific amount of order diverges at T C, yielding a transition that is mathematically similar to Bose–Einstein condensation. At all temperatures above TC, the model matches the measured magnetic susceptibilities of crystalline EuO, Gd, Co and Ni, thus providing a unified picture for both the critical-scaling and Curie–Weiss regimes.
Mode of Action of Pectic Enzymes II. Further Purification of Exopolygalacturonate Lyase and Pectinesterase from Clostridium multifermentans

Exopolygalacturonate lyase and pectinesterase from Clostridium multifermentans were purified 156-fold and 178-fold, respectively, by gel filtration chromatography on Sephadex G-200. The activities of both enzymes coincided in a single protein peak. Profiles of the two activities also coincided in diethylaminoethyl-cellulose chromatography and zonal centrifugation. These studies indicated that the esterase and the lyase were either complexed or similar molecular species. The former seems more probable because of the relatively high molecular weight. Both activities were most stable at pH 6.0. The esterase was inactivated rapidly at pH 5 or 7. Lyase preparations were freed of pectinesterase activity by heating for 30 min at 38 C and pH 7.0.
Abstract 12098: Reproductive Lifespan and Risk of Cardiovascular Disease (CVD) in Women

Background: Earlier age at menopause is associated with higher risk for cardiovascular disease, and hormonal changes are suspected to be involved. Earlier age at menarche is associated with higher risk of type 2 diabetes, but its association with CVD has been inconclusive. We investigated the association of the duration of reproductive lifespan, accounting for both age at menarche and menopause, with incident CVD. Methods: We prospectively followed 83,169 Nurses’ Health Study participants without CVD at baseline, the year of reported menopause, through 2010. CVD was defined as coronary heart disease (CHD; nonfatal myocardial infarction or fatal) and stroke (nonfatal or fatal). The duration of reproductive lifespan was generated by subtracting age at menarche from age at menopause. The relative risks were estimated using Cox proportional hazard regression with adjustment for potential confounders. Results: The median reproductive lifespan was 36 years (IQR 31-39). A shorter reproductive lifespan was associated with higher risk of incident CVD with multivariable adjustment for demographic, reproductive, and lifestyle factors, as well as prevalent and incident diabetes, hypertension, and hypercholesterolemia (RR 1.30 [95% CI 1.20-1.41] comparing duration Conclusion: A shorter duration of reproductive lifespan is associated with higher risk of CVD.
Civil War Transitions in Central America

This paper analyzes the impact of civil war on regime change, a longstanding concern in comparative politics and, more recently, in international relations. It focuses on Central America, a region where several countries underwent transitions to democracy in the wake of civil war during the second half of the twentieth century. It argues that armed conflict, not increasing levels of economic development, led to political change. Violence liquidated stubbornly resilient autocracies in El Salvador and Nicaragua, catalyzed the democratization of Costa Rican politics, and was the backdrop to regime liberalization in Guatemala. Post-war negotiations, at a time when Cold War bipolarity was ending, led to the establishment of more open, civilian regimes on the isthmus. This paper also notes that the transition from autocracy was enormously costly in both lives and economic well-being, which helps to explain why political change has given birth to low quality democracies or mixed regimes on the isthmus, ones that also have witnessed the explosion of criminal and drug-related violence.
Stimulation of synthesis and release of brain-derived neurotropic factor from intestinal smooth muscle cells by substance P and pituitary adenylate cyclase-activating peptide

Background Brain-derived neurotrophic factor (BDNF) is a neurotrophin present in the intestine where it participates in survival and growth of enteric neurons, augmentation of enteric circuits, and stimulation of intestinal peristalsis and propulsion. Previous studies largely focused on the role of neural and mucosal BDNF. The expression and release of BDNF from intestinal smooth muscle and the interaction with enteric neuropeptides has not been studied in gut. Methods The expression and secretion of BDNF from smooth muscle cultured from the rabbit intestinal longitudinal muscle layer in response to substance P (SP) and pituitary adenylate cyclase-activating peptide (PACAP) was measured by western blot and enzyme-linked immunosorbent assay. BDNF mRNA was measured by reverse-transcription polymerase chain reaction. Key Results The expression of BNDF protein and mRNA was greater in smooth muscle cells (SMCs) from the longitudinal muscle than from circular muscle layer. PACAP and SP increased the expression of BDNF protein and mRNA in cultured longitudinal SMCs. PACAP and SP also stimulated the secretion of BDNF from cultured longitudinal SMCs. Chelation of intracellular calcium with BAPTA (1,2-bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid) prevented SP-induced increase in BDNF mRNA and protein expression and SP-induced secretion of BDNF. Conclusions & Inferences Neuropeptides known to be present in enteric neurons innervating the longitudinal layer increase the expression of BDNF mRNA and protein in SMCs and stimulate the release of BDNF. Considering the ability of BDNF to enhance smooth muscle contraction, this autocrine loop may partially explain the characteristic hypercontractility of longitudinal muscle in inflammatory bowel disease.
A Path-Consistent Singleton Modeling (CSM) Algorithm for Arc-Constrained Networks

There is very little of “time” in a temporal constraint propagation algorithm. Most of these algorithms could easily handle reasoning over any domain mapable onto rational numbers, e.g., weight, frequency, luminosity, etc. Actually some of these algorithms are capable of handling more sophisticated domains than those mapped onto rational numbers, e.g., intervals, or partially ordered objects (say, time). In this article we have generalized such an algorithm, which was originally developed for time-interval domain, to any generic domain, where binary constraints are expressed over arcs of the constraint network. Given the composition table for the primitive relations between a pair of the domain entities (e.g., intervals) as an additional input along with a constraint graph, the algorithm would generate all consistent singleton models for a given network. The algorithm is also extended here to handle uncertainty values.
T-cell immunoglobulin and mucin domain 4 (TIM-4) signaling in innate immune-mediated liver ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (IRI), an innate immunity-driven inflammation response, occurs in multiple clinical settings including liver resection, transplantation, trauma, and shock. T-cell immunoglobulin and mucin (TIM)-4, the only TIM protein not expressed on T cells, is found on macrophages and dendritic cells. The regulatory function of macrophage TIM-4 in the engulfment of apoptotic/necrotic bodies in innate immunity-mediated disease states remains unknown. This study focuses on the putative role of TIM-4 signaling in a model of liver warm ischemia (90 minutes) and reperfusion. The ischemia insult triggered TIM-4 expression by stressed hepatocellular phosphatidylserine (PS) presentation, peaking at 6 hours of reperfusion, and coinciding with the maximal hepatocellular damage. TIM-4-deficient or wild-type WT mice treated with antagonistic TIM-4 monoclonal antibody (mAb) were resistant against liver IRI, evidenced by diminished serum alanine aminotransferase (sALT) levels and well-preserved hepatic architecture. Liver hepatoprotection rendered by TIM-4 deficiency was accompanied by diminished macrophage infiltration/chemoattraction, phagocytosis, and activation of Toll-like receptor (TLR)2/4/9-dependent signaling. Correlating with in vivo kinetics, the peak of TIM-4 induction in lipopolysaccharide (LPS)-activated bone marrow derived-macrophages (BMM) was detected in 6-hour cultures. To mimic liver IRI, we employed hydrogen peroxide-necrotic hepatocytes, which readily present PS. Indeed, necrotic hepatocytes were efficiently captured/engulfed by WT (TIM-4+) but not by TIM-4-deficient BMM. Finally, in a newly established model of liver IRI, adoptive transfer of WT but not TIM-4-deficient BMM readily recreated local inflammation response/hepatocellular damage in the CD11b-DTR mouse system. Conclusion: These findings document the importance of macrophage-specific TIM-4 activation in the mechanism of hepatic IRI. Macrophage TIM-4 may represent a therapeutic target to minimize innate inflammatory responses in IR-stressed organs. (Hepatology 2014;60:2051–2063)
Constraints on Accrual Components of Earnings in Equity Valuation

In this study, we extend the findings of Barth, Beaver, Hand, and Landsman (1999) by providing empirical evidence that for three levels of disaggregated earnings, (1) the structure provided by the Feltham-Ohlson model aids in predicting equity market values, and (2) forecasting of equity market values based on firms partitioned into industry groupings is superior to constraining all firms to have the same model parameters. We also find that disaggregating earnings into cash flows and total accruals generally yields better forecasts of equity market values. However, the efficacy of further disaggregation of total accruals into its primary components for forecasting equity market values appears to be industry-specific.
Pricing the razor: A note on two-part tariffs☆

The “razor-and-blades” pricing strategy involves setting a low price for a durable basic product (razors) and a high price for a complementary consumable (blades). In a timeless model, Oi (1971) showed that if consumers' demand curves differ and do not cross and unit costs are constant, a monopolist should always price blades above cost. This note studies the optimal razor price. With a uniform distribution of parallel linear demand curves it is never optimal to sell the razor below cost, while with two types of consumers and non-crossing linear demands it is optimal to do so for some parameter values
Effects of Refractive-Index Mismatch and Scattering on Simultaneous Spatial and Temporal Focusing

We theoretically and experimentally demonstrate the pulse broadening effects of scattering and refractive-index mismatch on simultaneous spatial and temporal focusing.
Is diabetes mellitus associated with increased incidence and disease-specific mortality in endometrial cancer? A systematic review and meta-analysis of cohort studies.

Objective To assess the association between diabetes mellitus (DM) and the incidence and disease-specific mortality of endometrial cancer (EC).
Associations between self-rated vision score, vision tests, and self-reported visual function in the Salisbury Eye Evaluation Study.

PURPOSE We attempt to understand the determinants of self-rated vision status by examining associations with vision tests, self-reported visual function, demographic, and health-status characteristics. METHODS Participants included 2467 individuals, aged 65 to 84 years, in a longitudinal, population-based cohort study. Participants rated their vision status from 0 to 10. Visual acuity, contrast sensitivity, stereoacuity, and visual fields were assessed. The Activities of Daily Vision Scale (ADVS) questionnaire was administered. Multivariate ordinal and multinomial logistic-regression models examined the association of demographic, health-status characteristics, vision tests, and ADVS subscales with self-rated vision status score. Odds ratios described the association of these characteristics with reporting better vision status. RESULTS Better visual acuity, contrast sensitivity, stereoacuity, and visual fields were associated with increased odds of reporting better vision status. Among the vision tests, a 2-line increase in visual acuity was most likely to result in an individual reporting better vision status (odds ratio, 1.49; 95% confidence interval [CI], 1.30-1.70). A 5-point increase in the near vision and far vision ADVS subscale scores was associated with increased odds of reporting good versus poor vision status. A 5-point increase in the near vision subscale was most likely to result in an individual reporting good versus poor vision status (odds ratio, 1.38; 95% CI, 1.28-1.50). CONCLUSIONS Self-rated vision status is a multidimensional measure. Near-vision visual function, visual acuity, and contrast sensitivity are important determinants of self-rated vision status in an elderly population. This understanding may improve the ability of eye care providers to maximize self-rated vision status among their patients.
Droplet formation from a pulsed vibrating micro-nozzle

Micro-droplet formation from a passive vibrating micro-nozzle driven by a pulsed pressure wave is numerically simulated. The micro-nozzle is formed from an orifice in a thin walled plate that is allowed to freely vibrate due to the pressure loading on the plate. The analysis couples the fluid flow from the nozzle and the resultant droplet formation with the nozzle vibration calculated using large deflection theory. The problem is made nondimensional based on the capillary parameters of time, velocity and pressure. The applied pressure and nozzle material properties are varied to alter the vibration characteristics of the orifice plate used to form the nozzle. The initiation of drop formation is found to coincide with a threshold impulse input, defined as the product of the pressure magnitude and the pulse duration. Increasing the impulse can result in multiple satellite droplet formation, but the effect on the primary droplet size is minor. The vibration of the nozzle only weakly influences the droplet break-off time, but is shown to significantly affect the droplet volume, shape, and satellite droplet formation.
An Uncommon Mimic of an Acute Asthma Exacerbation

Foreign body aspiration in adults has a variety of clinical presentations and often goes unrecognized. We describe the case of a patient who experienced crack cocaine aspiration and presented with symptoms of an acute asthma exacerbation requiring mechanical ventilation until the eventual diagnosis and bronchoscopic removal of the foreign body.
In-pipe wireless microrobot

An in-pipe microrobot which moves at 10 mm/s in a pipe of 15 mm diameter without power supply wire is developed. The robot consists of a microwave energy supply device, a locomotive mechanism using a piezoelectric bimorph actuator, and a control circuit. The energy supply device consists of rectifying circuits and a compact receiving antenna. The required energy of 200 mW is supplied via microwave without wire. 14 GHz microwave is rectified into DC electric energy at a high converting efficiency of 52%. The locomotive device of multi-layered bimorph actuator is newly developed and consumes only 50 mW. The control circuit consists of a saw tooth generator and a programmable logic device, and controls the direction of the robot motion by outside light signal.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Design of fluidized‐bed fermentors

Designing a fluidized-bed bioreactor requires choosing the best support particle (if any). Effectiveness factors (proportional to reactor volumetric productivity) are derived for flocs, solid spherical supports, porous supports, and adsorbent supports. The derivation demonstrates a mathematical procedure for reducing the diffusion/uptake equations for many components (substrates and inhibitory products) to a single equation, and for identifying the limiting component. With solid supports there exists a film thickness that maximizes the effectiveness, and the design objective is to keep the film near this optimum throughout the bed. This involves consideration of the effect of support particle density and film growth on bed stratification. Other considerations in packing support particles are obtaining reasonable values for bed height and diameter, minimizing mass transfer resistance between liquid and biomass, and preventing surface shear from stripping off the biomass. 20 references.
Mössbauer measurements of quadrupole-moment ratios of the first excited 2+ states of 176, 178 and 180Hf

Abstract The quadrupole-moment ratios of the first excited 2 + states of 176 Hf and 180 Hf have been measured with the Mossbauer effect following Coulomb excitation. The target was a single crystal of metallic hafnium with its c -axis making an angle of 45° with the surface of the crystal. Three absorbers of cubic crystals of HfC were prepared with seperated 176, 178 and 180 Hf isotopes. The determined ratios are Q 22 (80): Q 22 (178): Q 22 (176) = 1 : (1.03 ± 0.02). These results are compared with the predictions from the rotational model.
Results from the cognitive changes and retirement among senior surgeons self-report survey.

Background The Cognitive Changes and Retirement among Senior Surgeons (CCRASS) study suggested that although subjective cognitive awareness may play a role in surgeons' retirement decisions, self-perceived cognitive decline did not predict objective cognitive performance. This article summarizes results from all participants who completed the survey portion of the CCRASS study. Study Design A survey examining subjective cognitive changes, changes in caseload, involvement in new technology, and retirement decisions, was administered to 995 surgeons at annual meetings of the Clinical Congress of the American College of Surgeons between 2001 and 2006. Results Forty-five percent reported increased caseload volume and 48% reported increased caseload complexity during the previous 5 years. In addition, 75% and 73% denied any recent changes in memory recall or name recognition, respectively. Increasing age was associated with decreases in clinical caseload and complexity. The majority of respondents across all age groups reported active participation in either learning (64%) or contributing (13%) to new technology in the field. Among surgeons with no imminent plans for retirement, 58% reported that a retirement decision will be based on skill level. Conclusions Increasing age was associated with decreases in caseload and case complexity. But a steady proportion of surgeons, even in the oldest age group, are active in new surgical innovations and challenging cases. Most reported no changes in perceived cognitive abilities. The majority of surgeons who had made no decision to retire reported that their decision will be based on skill level rather than age.
Concentrations of prolactin and LH after administration of Met-enkephalin analogue (FK 33-824) to gilts during the follicular phase

The influence of methionine-enkephalin analogue (FK 33-824) administration upon prolactin and luteinizing hormone (LH) secretion in follicular phase gilts was studied. In experiment I, gilts, selected at random, received intravenous bolus injections of FK 33-824 or saline at 4 μg kg−1 body weight (BW) on Days 16 or 19 of the estrous cycle. Peripheral blood samples were collected every 15 min from 3 h before to 6 h after administration of FK 33-824 or saline. In experiment II, gilts were infused for 4 h with saline (N = 4) or FK 33-824 at a rate of 6.2 μg kg−1 BW h−1 (N = 4) on Day 19 of the estrous cycle. At the onset of continuous infusion, treated gilts received a bolus intravenous injection of FK 33-824 at a dose of 4 μg kg−1 BW. On Day 19 of the cycle, four additional gilts were also infused for 4 h with FK 33-824 as in experiment II. Two of the gilts received four injections of naloxone (2 mg kg−1 BW) at 1-h intervals beginning 15 min before the infusion of FK 33-824 and the remaining two gilts were injected with 100 μg of gonadotropin-releasing hormone (GnRH) 2 h after the beginning of FK 33-824 infusion. Blood samples were collected every 15 min for 4 h before, during and 4 h after infusion. Bolus injections of FK 33-824 resulted in increased (P < 0.05) prolactin concentrations on Day 19 of the estrous cycle but not on Day 16. Bolus injections of the opioid agonist did not influence LH profiles. Continuous infusion of FK 33-824 on Day 19 of the cycle elevated (P < 0.05) plasma prolactin concentrations and decreased (P < 0.05) LH concentrations and number of LH pulses. These effects of FK 33-824 were reversible by naloxone. Release of LH in response to GnRH injection during continuous infusion of FK 33-824 was observed. The results suggest an involvement of the opioid system in regulation of prolactin secretion and revealed an alteration of LH secretion when gilts were subjected to prolonged opioid influences during the late follicular phase.
Precursors to number: Equivalence relations, less-than and greater-than relations, and units

Infants' knowledge need not have the same structure as the mature knowledge that develops from it. Fundamental to an understanding of number are concepts of equivalence and less-than and greater-than relations. These concepts, together with the concept of unit, are posited to be the starting points for the development of numerical knowledge.
Multiasteroid Comet Missions Using Solar Electric Propulsion

Multitarget flyby missions to asteroids and comets are attractive candidates for solar electric propulsion (SEP) application because SEP can efficiently provide the thrust required for carefully chosen sequences of encounters. In this paper, techniques for finding encounter sequences for these missions are described, and examples involving flyby and rendezvous missions to P/Encke, P/Kopff and 20/Massalia are presented. In addition, examples of four asteroid flyby sequences are given. Encounters typically have flyby speeds on the order of 5-10 km/sec and are limited only by navigational capability as regards flyby distance, which is taken as zero in the study. Flights traversing the asteroid belt can be modified by SEP to pass one or more asteroids, and the performance penalty is small if the encounters are properly spaced.
Intensive radiotherapy of locally advanced bladder cancer

Over a 10-year period, 82 patients with locally advanced bladder cancer were treated by one of two intensive radiotherapy routines. They received either 320 rads/day for 11 consecutive treatment days; or two sets of 320 rads/day for six consecutive treatment days each, with a three-week rest interposed between sets. Side effects were briefly annoying, but quite tolerable. Good quality palliation was obtained. Uncorrected survival rates for the entire series were 48% at 1 year, 20% at 3 years, and 13% at 5 years.
Superfluid transition of 4He films adsorbed on multiply connected surfaces.

A Kosterlitz-Thouless--like approach is used to describe the superfluid transition of thin $^{4}\mathrm{He}$ films adsorbed on multiply connected surfaces such as packed powders or other porous materials. The elementary topological defect mediating the transition is a string linking two vortices of opposite circulation. The long-range interaction between strings gives rise to a phase transition which has a critical exponent for the superfluid density of \ensuremath{\nu}=0.64.
Engineering in genomics-combinatorial optimization in biology

The author suggests that the confidence which many biologists have in problem-solving methods is unwarranted and that there are very important limitations in almost all current methods for solving biological problems. The standard problem solving approach that computer scientists use is outlined. An example of an error in an evolutionary tree problem-the case of the African Eve-is discussed. >
Philosophical and religious influences on social welfare policy in the United States: The ongoing effect of Reformed theology and social Darwinism on attitudes toward the poor and social welfare policy and practice

• Summary: This article explores the historical and contemporary philosophical and religious influences of social welfare policy and programs in the United States. A discussion of Weber's critique ...
Numerical Analysis of a Slider Bearing with a Heterogeneous Slip/No-Slip Surface

The behavior of a fluid-film bearing depends on the boundary conditions at the interfaces between the liquid and the solid bearing surfaces. For almost all solid surfaces, the no-slip boundary condition applies. However, a number of researchers have recently found that slip can occur with specially engineered surfaces. These include molecularly smooth surfaces and surfaces with micron-scale patterns. By constructing an engineered heterogeneous surface on which slip occurs in certain regions and is absent in others, the flow in the liquid film of a bearing can be altered, and such characteristics as load support and friction can be improved. In the present study, a numerical analysis of a slider bearing with such an engineered slip/no-slip surface is analyzed. Slip is assumed to occur when a critical shear stress is exceeded and follows the Navier relation. The results show that with a critical shear stress of zero, a significant increase in load support and decrease in friction can be achieved with an app...
Metabolic reprogramming by class I and II histone deacetylases

Accumulating evidence suggests that protein acetylation plays a major regulatory role in many facets of transcriptional control of metabolism. The enzymes that catalyze the addition and removal of acetyl moieties are the histone acetyl transferases (HATs) and histone deacetylases (HDACs), respectively. Several recent studies have uncovered novel mechanisms and contexts in which different HDACs play crucial roles in metabolic control. Understanding the role of class I and II HDACs in different metabolic programs during development, as well as in the physiology and pathology of the adult organism, will lead to novel therapeutics for metabolic disease. Here, we review the current understanding of how class I and class II HDACs contribute to metabolic control.
The role of attentional networks in voluntary task switching

Coordination of task choice and performance in multitask environments likely involves attentional processes. Subjects completed the Attention Network Test (ANT) and a voluntary task-switching procedure. Task choice, but not task performance, was correlated with the executive score from the ANT, with higher switch probabilities for subjects with more efficient executive control networks. Task performance was correlated with the alerting score, with larger response time switch costs for subjects with larger alerting scores. The dissociation of task choice and task performance measures in terms of the pattern of correlations with attentional networks suggests that these two measures may reflect different cognitive processes engaged in voluntary task switching.
Distinguishing factors for asymptomatic colonoscopy screening.

Demographic, medical history, physician factors, knowledge, beliefs and perceived barriers related to colorectal cancer (CRC) and CRC screening were compared for age-eligible individuals who received asymptomatic colonoscopy screening (n = 100) versus those who did not receive any kind of CRC screening (n = 142). All participants had health insurance that covered the full cost of colonoscopy screening. Screeners were more likely to have lower levels of income and education, to know the purpose of a colonoscopy, believe it was more normative, and report fewer barriers. Addressing these and other factors associated with CRC screening warrant testing as empirically based interventions.
The neurobiology of Zebra Finch song: insights from gene expression studies

Male Zebra Finches (Taeniopygia guttata) sing a unique, stereotyped song that they learn from a tutor during development. A set of interconnected areas of the brain work together so that the birds can perceive, learn and produce song. In this review, we introduce the major components of the song system and describe evidence for how each might contribute to these three aspects of song. In particular, we highlight studies that have measured patterns of gene expression in the song system. These experiments clarify the structural organisation, and reveal functional activities, of the neural system underlying vocal communication. The utility of gene expression studies has been greatly enhanced with the release of the Zebra Finch genome. Investigation of gene expression in the song system will therefore continue to be a powerful way to connect the workings of this neural circuit with the behaviour of song. Zebra Finches sing a soft song that sounds squeaky and cheerful to the human ear and, perhaps, more mechanical than musical. (Richard Zann, ‘The Zebra Finch’, 1996)
Graph-based Dynamic Analysis: Efficient Characterization of Dynamic Timing and Activity Distributions

In light of increasing energy overheads required to guarantee correctness as variations increase with continued technology scaling, better-than-worst-case (BTWC) design has become a hot topic. Several BTWC design techniques utilize dynamic information like path activity when optimizing a design and rely on path-based analysis to determine the dynamic slack distribution of a workload running on a processor and subsequently optimize a design. In this paper, we show that path-based techniques are not scalable, due to the enormous number of paths in modern designs, and can also result in incorrect results. We propose a graph-based technique for performing dynamic timing and activity analysis of a workload on a processor that addresses the limitations of path-based techniques. Our tool has significantly lower runtime and memory requirements than path-based tools. Consequently, we can perform analysis for larger designs over longer time windows in a shorter amount of time. We also propose two optimizations that improve the performance of our tool.
State observer for the aluminum reduction process

The reduction of aluminum ore form alumina to metallic aluminum is done by dissolving the core in a cryolite bath at approximately 950 degrees C and passing DC current through the solution. Current flow through a typical cell can range from 75,000 to 200,000 Amperes, generating extremely strong electromagnetic fields. Common mode voltages of up to 800 VDC occur on reduction cell frames. Although the process is both complex and extremely energy intensive, it is generally only crudely instrumented because the hostile environment destroys any sensor placed in the bath. This paper describes a new approach to aluminum cell control employing the measurement of 'peripheral' process variables and the use of extensive modeling of the cell dynamics. A form of state observer is used to deduce critical process variables from the measurement of available related parameters. An experimental system is being installed at Century Aluminum and will be tested and refined over the coming year.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Densification of Shock-Treated Aluminum Nitride and Aluminum Oxide

The structures of aluminum nitride and aluminum oxide powders have been modified by explosive shock treatment at pressures from 4 to 27 GPa. Shock-induced dislocations in AlN were apparently responsible for enhancement in hot pressing behavior. In Al/sub 2/O/sub 3/ an increase of 3 to 4 times in densification rates after shocking resulted from rapid sintering of aggregates in the powder.
Use of germicides in the home and the healthcare setting: is there a relationship between germicide use and antibiotic resistance?

Background. The spread of antibiotic‐resistant pathogens represents an increasing threat in healthcare facilities. Concern has been expressed that the use of surface disinfectants and antiseptics may select for antibiotic‐resistant pathogens. Objective. To review the scientific literature on whether there is a link between use of germicides (ie, disinfectants and antiseptics) and bacterial resistance to antibiotics. In addition, we will review whether antibiotic‐resistant bacteria exhibit altered susceptibility to germicides that are recommended for use as disinfectants or antiseptics. Design. A review of the appropriate scientific literature. Results. In the laboratory, it has been possible to develop bacterial mutants with reduced susceptibility to disinfectants and antiseptics that also demonstrate decreased susceptibility to antibiotics. However, the antibiotic resistance described was not clinically relevant because the test organism was rarely a human pathogen, the altered level of antimicrobial sus...
Increase of Plasma TSH Concentration Following Injection of Purified Hypothalamic TRF

A purified preparation of TSH-releasing factor (TRF), specific activity 30 U/mg, of sheep hypothalamus origin, elevates the levels of circulating plasma TSH from 21 to 197 mU/100 ml in 3 min following intravenous injection in normal animals; even though less marked in amplitude, the same effect is seen in thyroidectomized animals. The material has no effect in hypophysectomized animals. (Endocrinology 77: 792, 1965)
Number of scaling factors in incommensurate systems

The authors study the scaling properties of an incommensurate system which obeys simple clustering rules, the one-dimensional tight-binding Schrodinger equation with a Fibonacci sequence potential. They find that the clustering rules do not guarantee a finite number of scaling factors. They find the energy spectrum by recursion. The clustering rules and recursion relations suggest different descriptions of the same spectrum. Based on the thermodynamic formalism, they compare these descriptions, calculate their associated scaling functions, and construct the mapping between them.
Impaired stimulation of gluconeogenesis during prolonged hypoglycemia in intensively treated insulin-dependent diabetic subjects.

Defective glucose counterregulation commonly seen in intensively treated insulin-dependent diabetes (IDDM) is mediated in part by a failure of compensatory stimulation of hepatic glucose production. Since the response of the liver to insulin-induced hypoglycemia normally involves activation of gluconeogenesis, we measured [14C]alanine conversion to [14C]glucose (a qualitative index of gluconeogenesis) and glucose production (using [3-3H]glucose) in seven intensively treated type I diabetic subjects (hemoglobin-A1, 7.1 +/- 0.4%) during low dose infusion of insulin (0.3 mU/kg.min for 210 min). IDDM patients received insulin overnight to maintain euglycemia before study. Although insulin levels rose to a similar extent as those in normal control subjects (n = 6), the fall in plasma glucose was markedly greater in IDDM (2.5 +/- 0.2 vs. 3.64 +/- 0.2 mM in controls; P < 0.01). The glucagon response was totally lost in IDDM, and epinephrine release was delayed and slightly reduced compared to that in control sub...
Low-cost fire response tests for cellulose insulation

The widespread use of cellulose insulation and the large number of small manufacturers makes low-cost fire response tests desirable for evaluating the fire safety aspects of this material. Various laboratory tests are discussed and some test data obtained at the University of San Francisco are presented.
Effects of Quaternary Sea Level Cycles on Strontium in Seawater

Abstract The effects of Quaternary sea level changes on the Sr budget of the ocean are investigated using coupled numerical models of the seawater Sr and Ca budgets. Glacial/interglacial sea level cycles influence the Sr concentration of seawater directly through the periodic exposure and weathering of aragonite on continental shelves and indirectly by modulating the location and extent of carbonate deposition in the ocean. As sea level recedes, brief pulses of Sr are added to the ocean from recrystallization of shelf aragonite; this flux at its maximum is nearly ten times larger than the combined riverine and hydrothermal influx. The large shelf recrystallization fluxes during glacial maxima produce rapid increases in the Sr/Ca ratio of seawater despite the long residence time of Sr in the ocean. Variations in the ratio of aragonitic vs. calcitic sedimentation also influence on the Sr content of seawater because the Sr partitioning coefficient is higher in aragonite; however, this effect is minor compared to shelf aragonite recrystallization. Based on a variety of sensitivity tests, the amplitude of Sr/Ca variations ranges from 1 to 3 % and is maximized by constant rates of total carbonate deposition, extensive aragonite recrystallization, and carbonate budgets which include dissolution of shelf carbonates. Such variation is sufficient to produce up to 1.5°C errors in paleotemperatures calculated from coral Sr/Ca ratios since the last glacial maximum.
The Mechanical Stability of Extra-Articular Distal Radius Fractures With Respect to the Number of Screws Securing the Distal Fragment

Purpose The treatment of distal radius fractures with volar locked plating (VLP) has gained popularity. Many different designs and sizes of plates afford a wide variety of configurations of locking screws that can be placed into the distal fracture fragment. The purpose of this study was to determine whether using half of the distal locking screws decreased stability when compared with using all possible distal locking screws with 4 different VLP systems. Methods Twenty-four identical synthetic distal radius sawbone models were instrumented with 1 of 4 designs of VLP devices over a standardized dorsal wedge osteotomy to simulate a dorsally comminuted, extra-articular distal radius fracture. Distal locking screws were placed in varying configurations. Six radii per plate model with different screw configurations then underwent axial loading, volar bending, and dorsal bending using a servohydraulic machine. Distal fragment displacement was recorded using a differential variable reluctance transducer. Results There was no significant difference in fracture fragment displacement when using half of the distal locking screw set compared with using the full screw set. Mean differences in displacement between half and full screws were less than 0.1 mm. All configurations had the greatest magnitude of displacement during axial loading. Mean displacement was less in plates containing 2 rows of distal locking screws (−0.4 mm) compared with plates containing 1 row (−0.6 mm). Conclusions Using half of the distal locking screws in VLP in an extra-articular, nonosteoporotic distal radial fracture model with noncyclical, nondestructive loading does not decrease construct stability compared with using all of the screws. Not filling all holes in VLP is more cost effective and does not sacrifice plate stiffness or construct stability. Plates with 2 rows of distal locking screws create more stable fixation than plates with 1 row of distal locking screws.