cssi/SciSciGPT-SciSciNet huggingface dataset:
Multispecies reactive tracer test in an aquifer with spatially variable chemical conditions, Cape Cod, Massachusetts: Dispersive transport of bromide and nickel

[1] Dispersive transport of groundwater solutes was investigated as part of a multispecies reactive tracer test conducted under spatially variable chemical conditions in an unconfined, sewage-contaminated sand and gravel aquifer on Cape Cod, Massachusetts. Transport of the nonreactive tracer bromide (Br) reflected physical and hydrologic processes. Transport of the reactive tracer nickel (Ni) complexed with an organic ligand (NiEDTA) varied in response to pH and other chemical conditions within the aquifer. A loss of about 14% of the Ni mass was calculated from the distribution of tracers through time. This loss is consistent with reversible adsorption of NiEDTA onto the iron and aluminum oxyhydroxide coatings on the aquifer sediments. The Ni consistently lagged behind Br with a calculated retardation coefficient of 1.2. Longitudinal dispersivities reached constant values of 2.2 and 1.1 m for Br and Ni, respectively, by at least 69 m of travel. The smaller dispersivity for Ni possibly was due to nonlinear or spatially variant adsorption of NiEDTA. In the upper, uncontaminated zone of the aquifer, longitudinal dispersion of Ni was greater than that of Br early in the test as a result of reversible adsorption of NiEDTA. In general, transverse dispersivities were much smaller (horizontal: 1.4–1.5 × 10−2 m; vertical: 0.5–3.8 × 10−3 m) than the longitudinal dispersivities. The Br results are similar to those from a test conducted eight years earlier, suggesting that transport parameters are spatially stationary within the aquifer at the scale of 300 m covered by the spatially overlapping tests. A significant difference between the two tests was the travel distance (69 and 26 m) needed to reach a constant longitudinal dispersivity.
Modulation of retinoid signalling through NGF-induced nuclear export of NGFI-B

The retinoid-X receptor (RXR) regulates multiple hormonal pathways through heterodimerization with nuclear receptors such as the all-trans retinoic acid receptor (RAR). The orphan nuclear receptor NGFI-B (also called Nur77) can heterodimerize with RXR. Here we show that nerve growth factor (NGF) induces the phosphorylation of Ser 105 of NGFI-B in PC12 phaeochromocytoma cells, resulting in translocation of the NGFI-B-RXR heterodimer complex out of the nucleus using nuclear export signals within NGFI-B. As a consequence of the redistribution of RXR, the transcriptional activity of RXR-RAR is reduced. NGFI-B-mediated nuclear export of receptors may serve as a mechanism for crosstalk between NGF and retinoid pathways.
Incentive Fees and Mutual Fund Volatility Timing

This paper shows that compensation incentives partly drive fund managers' market volatility timing strategies. Larger management fees are associated with less counter-cyclical or more pro-cyclical volatility timing. Fund investment objectives and styles also partly determine volatility timing. Funds with more aggressive styles time volatility more counter-cyclically. Thus, managers may try to outperform the general market by adopting aggressive styles, while dynamically hedging portfolio volatility using counter-cyclical volatility timing. We also find that fund managers systematically change their portfolio betas in response to aggregate equity fund cash flows. The average effects of volatility timing and fund flow timing on fund performance are mostly positive for funds that increase their betas when conditional volatility and fund flows increase (i.e., pro-cyclical timers).
Neuro-Dynamic Programming: An Overview and Recent Results

Neuro-dynamic programming is a methodology for sequential decision making under uncertainty, which is based on dynamic programming. The key idea is to use a scoring function to select decisions in complex dynamic systems, arising in a broad variety of applications from engineering design, operations research, resource allocation, finance, etc. This is much like what is done in computer chess, where positions are evaluated by means of a scoring function and the move that leads to the position with the best score is chosen. Neuro-dynamic programming provides a class of systematic methods for computing appropriate scoring functions using approximation schemes and simulation/evaluation of the system’s performance.
Identification of the PhoB Regulon and Role of PhoU in the Phosphate Starvation Response of Caulobacter crescentus

ABSTRACT An ability to sense and respond to changes in extracellular phosphate is critical for the survival of most bacteria. For Caulobacter crescentus, which typically lives in phosphate-limited environments, this process is especially crucial. Like many bacteria, Caulobacter responds to phosphate limitation through a conserved two-component signaling pathway called PhoR-PhoB, but the direct regulon of PhoB in this organism is unknown. Here we used chromatin immunoprecipitation-DNA sequencing (ChIP-Seq) to map the global binding patterns of the phosphate-responsive transcriptional regulator PhoB under phosphate-limited and -replete conditions. Combined with genome-wide expression profiling, our work demonstrates that PhoB is induced to regulate nearly 50 genes under phosphate-starved conditions. The PhoB regulon is comprised primarily of genes known or predicted to help Caulobacter scavenge for and import inorganic phosphate, including 15 different membrane transporters. We also investigated the regulatory role of PhoU, a widely conserved protein proposed to coordinate phosphate import with expression of the PhoB regulon by directly modulating the histidine kinase PhoR. However, our studies show that it likely does not play such a role in Caulobacter, as PhoU depletion has no significant effect on PhoB-dependent gene expression. Instead, cells lacking PhoU exhibit striking accumulation of large polyphosphate granules, suggesting that PhoU participates in controlling intracellular phosphate metabolism. IMPORTANCE The transcription factor PhoB is widely conserved throughout the bacterial kingdom, where it helps organisms respond to phosphate limitation by driving the expression of a battery of genes. Most of what is known about PhoB and its target genes is derived from studies of Escherichia coli. Our work documents the PhoB regulon in Caulobacter crescentus, and comparison to the regulon in E. coli reveals significant differences, highlighting the evolutionary plasticity of transcriptional responses driven by highly conserved transcription factors. We also demonstrated that the conserved protein PhoU, which is implicated in bacterial persistence, does not regulate PhoB activity, as previously suggested. Instead, our results favor a model in which PhoU affects intracellular phosphate accumulation, possibly through the high-affinity phosphate transporter.
Use of enterprise social software to support organization and people sensemaking

There has been considerable recent interest in the use of Web 2.0/social software in organizational settings. In this talk, several IBM research projects will be discussed in which social software was tailored for business and deployed within a large global enterprise (IBM). These projects include a social bookmarking service (dogear), a lightweight file sharing application (cattail) and a social network application (beehive). Two important research topics will be discussed. First, we explore various application capabilities that support and encourage social interaction and application adoption. Several incentive systems were tested in field trials and showed sustained increase in user participation levels. Recommender applets were also trialed to understand their ability to support the increased end-user ”production” of content. The second topic will be the use of social software to promote sensemaking for people and the organization. In particular, we explore the integration of various social software applications with search tools, and the introduction of non-traditional work content (e.g., personal photos) to signal and support organizational acculturation.
Crossroads of Empire: The Middle Colonies in British North America – By Ned C. Landsman

The title conveys the topic of the book well: a history of the mid‐Atlantic region from the early seventeenth century to the Revolutionary period. Ned C. Landsman frames his focus on the middle col...
Do marginal firms in Bolivia benefit from formalizing

The seventh in a new impact series summarizes research which arose from research staff working together with operational staff on a World Bank Economic and Sector Work (ESW) on policies to increase the formality and productivity of firms in Bolivia. It is also illustrative of how an instrumental variables approach can be informative in impact evaluations.
Effects of Soybean Meal Sources and Level on Growth Performance of Weanling Pigs1

Abstract Three experiments were conducted to compare the effects of increasing solvent-extracted soybean meal ( SBM ) or extruded-expelled SBM ( EESOY ) in diets for early weaned pigs. Pigs were fed a control diet (no SBM) or diets containing 20% or 40% SBM or EESOY. In Exp. 1, diets were formulated with calculated values for SBM and EESOY. In Exp. 1, from d 0 to 14, no differences were observed in ADG or ADFI (P>0.05), but gain-to-feed ratio ( G:F ) decreased (linear, P TI ) values > 8 mg TI/g, suggesting under processing, whereas SBM only contained 0.05) were found between SBM sources. These results suggest that when processed properly, EESOY has similar nutritional value as SBM in nursery pig diets.
Helical Computed Tomography for Abdominal Imaging

Significant technologic advances have taken place in computed tomography (CT). Current-generation conventional CT scanners are able to image a slice of tissue in as little as 2 to 3 seconds and can acquire several consecutive images. Although it is a substantial improvement from the CT of 5 years ago, there remain practical limits to the utility of conventional CT imaging within the abdomen. Recently, a new type of CT gantry design ("slip-ring") and faster computers have contributed to the development of a new generation of CT scanners, the "helical" or "spiral" CT scanners.
HSAB theory and acute metal ion toxicity and detoxification processes

Abstract The theory of hard and soft acids and bases (HSAB theory) can be used to correlate information on metal ion toxicity and the relative effectiveness of therapeutic chelating agents with parameters used to characterize “hardness” and “softness”. HSAB considerations appear to govern at least some of the non-specific aspects of metal ion toxicity. They are also useful in explaining some of the known patterns of metal ion detoxification and how situations arise where the rate behavior, rather than equilibrium factors, may be of importance in determining the success of a given chelating agent in enhancing the excretion of a given toxic metal. In many instances an effective evaluation of the applicability of HSAB theory to such systems is prevented by the limited availability of the necessary biological data. The correlations found can be used to estimate the toxicity of chemical species for which HSAB parameters but not toxicity data are available, as well as to preselect the most promising chelating agents for therapeutic testing.
The Modern Educator

Today's educators must wear multiple hats-entertainer, personal coach, emergency responder, gizmo wizard, and social media guru-to be judged as informed and effective.
On estimation of bivariate biomarkers with known detection limits

To estimate the correlation coefficient between two measurements of viral load obtained from HIV-infected individuals, a Bernoulli/bivariate normal mixture model has been applied to provide a better fit for the high proportions of left censoring due to assay measurements falling below limits of detection (LD). In this paper, we investigate the relationship among several alternative likelihood-based methods; particularly we derive an explicit relationship between the maximum likelihood estimates based on the Bernoulli/bivariate normal mixture model for all data pairs and a left-truncated bivariate normal model for data pairs with one or two detectable values. With a case study and a set of Monte Carlo simulations, we demonstrated the potential impact of using an incorrect likelihood on the estimation of correlation coefficient from two random variables with known LD. Furthermore, we investigated the performance of nonparametric methods using Kendall's tau and Spearman's rank correlation with tie correction for left censoring, which have been used in practice. When data are simulated from a left-censored bivariate normal or a left-censored Bernoulli/bivariate normal mixture distribution, both Kendall's tau and Spearman's rank correlation tend to give biased estimates. The biases increase as the probability in the lower component and the proportions of left censoring increases. Further research on nonparametric methods is needed to deal with left censoring, especially in the presence of mixture distributions. Copyright © 2007 John Wiley & Sons, Ltd.
Partial purification and characterization of a β-N-acetylhexosaminidase from black cherry (prunus serotina EHRH.) seeds

Abstract A β-N-acetylhexosaminidase (β-NAHA) was purified 30-fold from hemogenates of mature black cherry seeds by DEAE-cellulose and Concanavalin A-Sepharose 4B chromatography. Extensive further purification was achieved by N- acetyl- D -glucosamine-agarose chromatography, but the enzyme thereafter required bovine serum albumin (BSA) for retention of activity. The purified enzyme showed highest acivity p- nitrophenyl -N- acetyl -β- D - glucosaminide (PNP-βGlcNAc) (optimum pH 4.5; Km, 0.49 mM) and p-nitrophenyl-N-acetyle-β-D-galactosaminide (PNP-β-GalNAC) (optimum pH 4.0; Km, 0.63 mM). Mixed-substrate experiments suggested that these substrates compete for the same active site. Lesser activity was shown towards p-nitrophenyl- and o- nitrophenyl -β- D - glucosides . p- Nitrophenyl -N- acetyl -α- D - glucosaminide , p- nitrophenyl -N- acetyl -α- D - mannosaminide and p- nitrophenyl -α- D - glucoside were not hydrolysed. The enzyme preparation lacked amygdalin hydrolase, prunasin hydrolase and p nitrophenyl -α- D - mannosidase activities and failed to release N-acetylglucosamine from a glyco-protein fraction derived from black cherry seeds by Concanavalin A-Sepharose 4B chromatography. β-NAHA activity was not stimulated by any metal ions tested and was unaffected by diethyldithiocarbamate, 2,2′-dipyridyl, 1,10-phenanthroline, iodoacetate and iodoacetamide.
The Abidjan Airport Concession: Facing Regional Aviation Liberalization

In July 1996, responsibility for operating and developing Abidjan Houphouet-Boigny airport, the main airport of Cote d9Ivoire, was transferred through a 15-year concession agreement from the government to AERIA, a French-led consortium. In the years that followed, traffic growth exceeded the forecasts of both the government and the concessionaire, leading to acceleration and revision of investment plans for the airport. But even as traffic grew, the external environment was on the cusp of significant change via an unprecedented initiative for the liberalization of civil aviation throughout the West and Central Africa region. While this initiative could spur increased demand for air-travel and cargo services, it also poses a potential threat to the Abidjan concession through enhanced competition for the airport9s largest airline, Air Afrique. Also, liberalization promises to increase competition among airports to serve as primary regional hubs.
Evidence for the involvement of cyclooxygenase activity in the development of cocaine sensitization.

Abstract Phospholipase A2 (PLA 2 ) activation generates the release of arachidonic acid (AA) and platelet-activating factor (PAF), two compounds which may be involved in neuroplasticity. In previous studies, we found that PLA 2 activation is involved in the development of stimulant sensitization. In the present study, we have examined the roles of AA and PAF in the development of stimulant sensitization using agonists and antagonists selective for PAF receptors or the induction of various AA cascade-mediated eicosanoids. Sprague–Dawley rats were treated for 5 days with cocaine (30 mg/kg) or d -amphetamine (1 mg/kg) preceded 15 min earlier by various antagonists, and then tested following a 10-day withdrawal period for cocaine (15 mg/kg) or d -amphetamine (0.5 mg/kg)-induced locomotion. Consistent with our earlier work, pretreatment with the PLA 2 inhibitor quinacrine (25 mg/kg) blocked the development of cocaine and amphetamine sensitization. The lipoxygenase (LOX) inhibitors nordihydroguaiaretic acid (NDGA) (5–10 mg/kg) and MK-886 (1 mg/kg) had no effect on cocaine sensitization. The PAF receptor antagonist WEB 2086 (5–10 mg/kg) reduced the development of cocaine sensitization. The cyclooxygenase (COX) inhibitors indomethacin (1–2 mg/kg), piroxicam (0.5–1 mg/kg), 6-methoxy-2-napthylacetic acid (6-MNA; 0.5–1 mg/kg), and NS-398 (0.5–1 mg/kg) blocked the development of cocaine sensitization. The COX inhibitors indomethacin (2 mg/kg) and 6-MNA (1 mg/kg) also reduced the development of amphetamine sensitization. Rats were administered bilateral intraventral tegmental area (VTA) injections of d -amphetamine (5 μg/side) or saline coadministered with indomethacin (0.5 μg/side) or vehicle three times over 5 days and were then tested after a 10-day withdrawal for d- amphetamine (0.5 mg/kg ip)-induced locomotion. Intra-VTA amphetamine induced a robust form of amphetamine sensitization, which was blocked by coadministration of indomethacin. Unilateral intra-VTA injections of PAF (1 μg) did not significantly alter cocaine (15 mg/kg ip)-induced locomotion when tested after a 3-day withdrawal. These findings suggest that COX, and possibly PAF, activity is involved in the development of stimulant sensitization. Neuroanatomical studies demonstrate that this may occur at the level of the VTA.
Determinants of locus of control orientation in male alcoholics.

Investigated various demographic correlates of locus of control orientation in 123 male alcoholics. The social functioning of alcoholics was associated significantly with locus of control. It was suggested that conflicting results among similar studies probably are due to the differeing social or demographic characteristics of the samples that were used.
Field-assisted nanopatterning of metals, metal oxides and metal salts

The tip-based nanofabrication method called field-assisted nanopatterning or FAN has now been extended to the transfer of metals, metal oxides and metal salts onto various receiving substrates including highly ordered pyrolytic graphite, passivated gold and indium-tin oxide. Standard atomic force microscope tips were first dip-coated using suspensions of inorganic compounds in solvent. The films prepared in this manner were non-uniform and contained inorganic nanoparticles. Tip-based nanopatterning on chosen substrates was conducted under high electric field conditions. The same tip was used for both nanofabrication and imaging. Arbitrary patterns were formed with dimensions that ranged from tens of microns to sub-20 nm and were controlled by tuning the tip bias during fabrication. Most tip-based nanopatterning techniques are limited in terms of the type of species that can be deposited and the type of substrates onto which the deposition occurs. With the successful deposition of inorganic species reported here, FAN is demonstrated to be a truly versatile tip-based nanofabrication technique that is useful for the deposition of a wide variety of both organic and inorganic species including small molecules, large molecules and polymers.
Analytical heat flow modeling of silicon-on-insulator devices

A physics-based analytical heat flow model for SOI devices is presented using the SOI silicon film thermal resistance, instead of the traditional SOI channel thermal resistance, to describe heat loss to substrate through buried/filed oxide (BOX/FOX). A relation between the silicon film thermal resistance and the channel thermal resistance is derived. The model reasonably predicts the temperature variation in the silicon film accounting for heat loss through BOX/FOX to the substrate and heat flow to the interconnects shorter than the interconnect characteristic thermal length. The developed model is applied to study heat exchange between devices. � 2003 Elsevier Ltd. All rights reserved.
Fine mapping of the amyloid β-protein binding site on myelin basic protein.

The assembly and deposition of amyloid β-protein (Aβ) in brain is a key pathological feature of Alzheimer’s disease and related disorders. Factors have been identified that can either promote or inhibit Aβ assembly in brain. We previously reported that myelin basic protein (MBP) is a potent inhibitor of Aβ fibrillar assembly [Hoos, M. D., et al. (2007) J. Biol. Chem. 282, 9952–9961; Hoos, M. D., et al. (2009) Biochemistry 48, 4720–4727]. Moreover, the region on MBP responsible for this activity was localized to the 64 N-terminal amino acids (MBP1–64) [Liao, M. C., et al. (2010) J. Biol. Chem. 285, 35590–35598]. In the study presented here, we sought to further define the site on MBP1–64 involved in this activity. Deletion mapping studies showed that the C-terminal region (residues 54–64) is required for the ability of MBP1–64 to bind Aβ and inhibit fibril assembly. Alanine scanning mutagenesis revealed that amino acids K54, R55, G56, and K59 within MBP1–64 are important for both Aβ binding and inhibition ...
Evaluation of vitrectomy machines as a source of false-positive culture contamination in endophthalmitis.

Purpose We sought to determine whether a venturi-aspiration vitrectomy machine could contaminate a vitrectomy culture. Methods Ninety vitrectomies were simulated in a hospital operating room and were cultured with standard techniques. An additional 90 control specimens were cultured in the exact same manner, but the vitrectomy machine was not used. Instead, the control specimens were placed directly into a sterile vitrectomy cassette. Contamination rates in the two groups were compared. Results Contamination occurred in four of 90 vitrectomy-simulation cultures and in three of 90 control cultures. This difference in contamination rate was not statistically significant. Conclusions Although the result of a culture of the vitrectomy effluent can be false-positive, the source of contamination is not likely to be the vitrectomy machine.
Reflections on Developing Student Authors: From Class Paper to Journal Publication.

In this article, I describe my reflections on developing student authors through a class research project. I review the assignment origins and description and my role in the students' developmental journey from transforming a class assignment to a publishable work.
Immunoaffinity localization of the enzyme xanthine oxidase on the outside surface of the endothelial cell plasma membrane.

Abstract Background: Reactive oxygen metabolites generated from endothelial xanthine oxidase (XO) trigger reperfusion injury in many organs. We evaluated the possibility that endothelial XO was localized on the endothelial cell surface, as well as within the cytoplasm. Methods: Primary cultures of bovine (BAECs) and porcine (PAECs) aortic endothelial cells were grown in media documented to be free of XO. Polyclonal and monoclonal antibodies were developed against XO. These antibodies were used to evaluate BAEC and PAEC for cell surface XO through immunofluorescence staining, hybridoma cell surface labeling, and endothelial cell surface binding. Results: These antibodies bound specifically to the surface of these cells when the membrane was shown to be intact and impermeable (and the cytoplasm inaccessible) to immunoglobulins. Moreover, hybridoma cells expressing monoclonal antibody to XO bound specifically to the endothelial cell surface. Finally, intact endothelial cells bound specifically to the anti-XO polyclonal antibodies immobilized to the surface of a Petri dish. The integrity of these endothelial cell plasma membranes was demonstrated by the subsequent growth and replication of these cells in culture. Conclusions: These findings indicate that XO is present on the outside surface of the endothelial cell plasma membrane. This would not only explain the known in vivo efficacy of intravascularly administered large molecular weight antioxidants (such as superoxide dismutase) but could have important implications for inflammatory signaling. (Surgery 1998;124:551-60.)
IMPINGEMENT DRYING OF POTATO CHIPS

The effect of superheated steam temperature (115, 130, and 145C) and convective heat transfer coefficient (100 and 160 W/m 2 C) on the drying rate and product quality attributes (shrinkage, density, porosity, color, texture, and nutrition loss) of potato chips was investigated. Furthermore, potato chips dried by impinging superheated steam (130 and 145C, h = 100 W/m 2 C) were compared to air dried (same conditions), commercial, and fried potato chips. Temperature and convective heat transfer coefficient had a significant effect on the drying rate during superheated steam impingement drying. Potato chips dried at higher drying temperature and convective heat transfer coefficient showed less shrinkage, lower bulk density, higher porosity, and darker color when compared to chips dried at lower temperatures and convective heat transfer coefficients. They were also less hard and had a lower vitamin C content. A higher rate of evaporation during the falling rate period was obtained when superheated steam drying was compared to air impingement drying. Potato chips produced using superheated steam impingement drying showed more shrinkage, higher bulk density, lower porosity, and lighter color than chips dried with air under the same temperature and with the same convective heat transfer coefficient (130, and 145C, h = 100 W/m 2 C). Moreover, superheated steam-dried potato chips retained more vitamin C during the drying process. Le sechage par impact peut etre une alternative pour la production de chips a faible teneur en lipide. Dans cette etude, l'effet d'une temperature de vapeur surchauffee (115, 130 et 145°C) et du coefficient de transfert de chaleur convective (100 et 600 W/m 2 C) sur le taux de sechage et les attributs de qualite (retrecissement, densite, porosite, couleur, texture et perte nutritive) de pommes de terre chips est examine. De plus, des chips sechees par impact de vapeur surchauffee sont comparees avec des chips sechees a l'air, commerciales et frites.
Childhood and adolescent thyroid carcinoma.

OBJECTIVES This analysis was performed to evaluate the influence of clinical and treatment factors on local tumor control, control of distant metastasis, survival, and complications in children and adolescents with thyroid carcinoma. METHODS The records of 56 children and adolescents with papillary and follicular carcinoma of the thyroid were reviewed. They ranged in age from 4 to 20 years. There were 43 females and 13 males. At diagnosis, 15 (27%) patients had disease confined to the thyroid, 34 (60%) had additional lymph node metastasis to the neck or upper mediastinum, and 7 (13%) also had lung metastasis. Treatment consisted of a total thyroidectomy in 48 patients, a subtotal thyroidectomy in 4 patients, and a lobectomy in 4 patients. All 56 patients received postoperative thyroid hormone suppressive therapy. 131I was administered to 82% (46 of 56) of patients after their initial surgery. RESULTS The overall survival rate was 98% with a follow-up of 0.6–30.7 years (with a median follow-up of 11.0 years). The one death that occurred in this patient population was the result of a congenital heart defect and was unrelated to thyroid carcinoma. The 10-year progression-free survival rate was 61%. Nineteen patients (34%) experienced a recurrence of their thyroid carcinoma. The time to first recurrence of disease ranged from 8 months to 14.8 years (mean, 5.3 years). None of those with disease confined to the thyroid developed recurrent disease. The recurrence rate was 50% (17 of 34) in patients with lymph node metastasis and 29% (2 of 7) in patients with lung metastasis (P = 0.02). Tumor characteristics were evaluated for time to first recurrence utilizing the logistic likelihood ratio test to predict disease recurrence. Thyroid capsule invasion (P = 0.02), soft tissue invasion (P = 0.03), positive margins (P = 0.006), and tumor location at diagnosis (thyroid only vs. thyroid and lymph nodes vs. thyroid, lymph nodes, and lung metastasis, P = 0.02) were significant for developing recurrent disease. Patients younger than 15 years old at diagnosis were more likely to have more extensive tumor at diagnosis than patients who were 15 years and older (thyroid only vs. thyroid and lymph nodes vs. thyroid, lymph nodes, and lung metastasis, P = 0.02). CONCLUSION Carcinoma of the thyroid in children and adolescents has little risk of mortality but a high risk of recurrence. Younger patients present with a more advanced stage of disease and are more likely to have disease recurrence. Total thyroidectomy and lymph node dissection, followed by postoperative 131I therapy, thyroid hormone replacement (suppressive) administration, and diligent surveillance are warranted. Cancer 2002;95:724–9. © 2002 American Cancer Society. DOI 10.1002/cncr.10725
Optimized graphical analysis of Gaussian and lognormal assumptions for intraocular and vascular pressure distributions

The design of optimized histogram and probability graphs needed to detect a lognormal distribution in surveys of intraocular pressure (IOP), mean ophthalmic arterial pressure (OAP) and mean ocular perfusion pressure (OPP) is described. Applications are demonstrated in a sample of 58 normal adult eyes.A logncrmal distribution was found for IOP and for OAP and OPP estimates obtained with a noncon-tact noncompressive method. Conversely, the absence of an identifiable linear distribution for OAP and OPP estimates obtained with compression ophthalmodynamometry was noteworthy.The implications of lognormality for definitions of a normal range and for correlations involving IOP, OAP and OPP data are briefly discussed.
Pharmacological inhibition of ALDH1A in mice decreases all-trans retinoic acid concentrations in a tissue specific manner

all-trans retinoic acid (atRA), the active metabolite of vitamin A, is an essential signaling molecule. Specifically the concentrations of atRA are spatiotemporally controlled in target tissues such as the liver and the testes. While the enzymes of the aldehyde dehydrogenase 1A family (ALDH1A) are believed to control the synthesis of atRA, a direct relationship between altered ALDH1A activity and tissue atRA concentrations has never been shown. To test whether inhibition of ALDH1A enzymes decreases atRA concentrations in a tissue specific manner, the potent ALDH1A inhibitor WIN 18,446 was used to inhibit ALDH1A activity in mice. The ALDH1A expression, atRA formation kinetics, ALDH1A inhibition by WIN 18,446 and WIN 18,446 disposition were used to predict the time course and extent of inhibition of atRA formation in the testis and liver. The effect of WIN 18,446 on atRA concentrations in testis, liver and serum were measured following single and multiple doses of WIN 18,446. ALDH1A1 and ALDH1A2 were responsible for the majority of atRA formation in the testis while ALDH1A1 and aldehyde oxidase contributed to atRA formation in the liver. Due to the different complement of enzymes contributing to atRA formation in different tissues and different inhibition of ALDH1A1 and ALDH1A2 by WIN 18,446, WIN 18,446 caused only a 50% decrease in liver atRA but testicular atRA decreased over 90%. Serum atRA concentrations were also reduced. These data demonstrate that inhibition of ALDH1A enzymes will decrease atRA concentrations in a tissue specific manner and selective ALDH1A inhibition could be used to alter atRA concentrations in select target tissues.
Reducing dietary fat from a meal increases the bioavailability of exogenous carbohydrate without altering plasma glucose concentration

The primary goal of this study was to determine the acute glycemic and endocrine responses to the reduction of fat content from a meal. On three separate occasions, nine overweight subjects (body m...
The declining significance of first-birth timing.

A rationale for the hypothesis that the impact of 1st-birth timing on the pace at which 2nd births occur declined for women married between 1950-69 is presented. The hypothesis is tested with proportional hazards models and data from the 1973 National Survey of Family Growth. Results support the hypothesis for white women but not for black. Most of the decline in the impact of 1st birth timing for whites arises from slower 2nd birth timing among women with a rapidly paced 1st-birth while women who delayed a 1st birth experience a reasonably uniform delay to 2nd birth over the period. The survey is a multi-stage area-probability cross-sectional sample of households and includes about 9800 women aged 15-44 who were ever-married or who had children of their own living in the household. The life table results show that for all whites it took 19 months for 25% of the mothers to have a 2nd birth 30 months for 50% and nearly 4 years before 3/4 had a 2nd birth. For all blacks the respective figures are 16 27 and 57 months. Women who delayed their 1st birth 18 months or longer took much longer to have a 2nd birth. Using the proportional hazards methodology both 1st birth timing and marriage cohort have a significant impact on 2nd birth timing among black women but there was no statistically significant interaction between these predictor variables. Efforts should be directed toward explaining why blacks and whites differ with respect to the declining significance of 1st birth timing. The declining influence of 1st birth timing among white women can largely be attributed to slower 2nd birth timing among women with shorter 1st birth intervals. Since only 4 marriage cohorts of whites were examined the results should be interpreted cautiously. Additionally the findings are restricted to women married by age 25. The childspacing patterns of women marrying later may be different. The decline in the importance of 1st birth timing predicting 2nd birth timing may have significant consequences. A rapidly paced 1st birth may not have the same negative socioeconomic consequences as in the past. 1st birth timing may have less impact on life-course events other than fertility. Since 1st birth timing may no longer predict 2nd birth timing to a great extent and expanded search for factors associated with the pace of 2nd births is in order.
Uplink capacity of satellite-based WCDMA networks

Satellite-based WCDMA systems have been proposed recently for commercial and military applications [1, 2]. In this paper we present an analytical expression for the pole capacity of geosynchronous satellite based WCDMA networks and identify the important factors such as dynamic traffic, fade margin, beam forming, and power control that influence the uplink capacity of satellite based WCDMA networks. We do not address the downlink capacity in this paper since uplink capacity is often the limiting factor on the overall capacity of these networks
M-Ras/R-Ras3, a transforming ras protein regulated by Sos1, GRF1, and p120 Ras GTPase-activating protein, interacts with the putative Ras effector AF6.

M-Ras is a Ras-related protein that shares ∼55% identity with K-Ras and TC21. The M-Ras message was widely expressed but was most predominant in ovary and brain. Similarly to Ha-Ras, expression of mutationally activated M-Ras in NIH 3T3 mouse fibroblasts or C2 myoblasts resulted in cellular transformation or inhibition of differentiation, respectively. M-Ras only weakly activated extracellular signal-regulated kinase 2 (ERK2), but it cooperated with Raf, Rac, and Rho to induce transforming foci in NIH 3T3 cells, suggesting that M-Ras signaled via alternate pathways to these effectors. Although the mitogen-activated protein kinase/ERK kinase inhibitor, PD98059, blocked M-Ras-induced transformation, M-Ras was more effective than an activated mitogen-activated protein kinase/ERK kinase mutant at inducing focus formation. These data indicate that multiple pathways must contribute to M-Ras-induced transformation. M-Ras interacted poorly in a yeast two-hybrid assay with multiple Ras effectors, including c-Raf-1, A-Raf, B-Raf, phosphoinositol-3 kinase δ, RalGDS, and Rin1. Although M-Ras coimmunoprecipitated with AF6, a putative regulator of cell junction formation, overexpression of AF6 did not contribute to fibroblast transformation, suggesting the possibility of novel effector proteins. The M-Ras GTP/GDP cycle was sensitive to the Ras GEFs, Sos1, and GRF1 and to p120 Ras GAP. Together, these findings suggest that while M-Ras is regulated by similar upstream stimuli to Ha-Ras, novel targets may be responsible for its effects on cellular transformation and differentiation.
Review of coal gasification technologies for the production of methane

Abstract One of the potential sources for methane for supplementing natural gas supply is coal. A variety of different technologies are available for converting coal to methane. The basic types of gasifiers and their advantages and disadvantages are reviewed. The major commercial and experimental processes are surveyed and the potential for improved technology is considered.
Zn(II) and Cu(II) Complexes with the Cluster-based Ligand [Re6(μ3-Se)8(PEt3)5(PTA)](SbF6)2 (PTA = 1,3,5-Triaza-7-phosphaadamantane)

Zn(II) and Cu(II) complexes of the cluster-based ligand [Re6(μ 3-Se)8(PEt3)5(PTA)](SbF6)2 (PTA = 1,3,5-triaza-7-phosphaadamantane), {Zn[Re6(μ 3-Se)8(PEt3)5(PTA)](NO3)3}(SbF6) (1) and {Cu[Re6(μ 3-Se)8(PEt3)5(PTA)](NO3)3}(SbF6) (2), were prepared and structurally characterized. They are the first N-coordinated Zn(II) and Cu(II) complexes wherein the PTA ligand displays an interesting and less-frequently observed P, N-coordination mode.
Obligations of engineering management in a large decentralized company

The obligations of engineering management and the methods for meeting these obligations are outlined. The author also discusses the relationships between marketing, product engineering, and manufacturing.
A Branching Process Model for Sand Avalanches

An analytically solvable model for sand avalanches of noninteracting grains of sand, based on the Chapman-Kolmogorov equations, is presented. For a single avalanche, distributions of lifetimes, sizes of overflows and avalanches, and correlation functions are calculated. Some of these are exponentials, some are power laws. Spatially homogeneous distributions of avalanches are also studied. Computer simulations of avalanches of interacting grains of sand are compared to the solutions to the Chapman-Kolmogorov equations. We find that within the range of parameters explored in the simulation, the approximation of noninteracting grains of sand is a good one.
Dissecting the Structure of LcrV from Yersinia pestis, a Truly Unique Virulence Protein

Abstract Last month in the February issue, Structure published the crystal structure of LcrV from Yersinia pestis , the infectious agent that causes plague. LcrV activity is essential for disease, and the structure of this protein provides a valuable tool to dissect the nature of its pathogenicity.
Studying cellular mechanics using magnetic tweezers and two-photon microscopy

The ability to apply quantifiable mechanical stresses at the microscopic scale is critical for studying cellular responses to mechanical forces. This necessitates the use of force transducers that can apply precisely controlled forces to cells while monitoring the responses non- invasively. This paper describes the development of a micro manipulation workstation integrating two-photon, 3-D imaging with a high-force, uniform-gradient, magnetic manipulator. The uniform-gradient magnetic field applies nearly equal forces to a large cell population, permitting statistical quantification of select molecular responses to mechanical stresses. The magnetic transducer design is capable of exerting over 200 pN of force on 4.5 micrometers diameter paramagnetic particles and over 800 pN on 5.0 micrometers ferromagnetic particles. These forces vary less than 10% over an area 200 x 200 micrometers 2. The compatibility with the use of high numerical aperture (approximately equals 1.0) objectives is an integral part of the workstation design allowing sub- micron resolution 3-D two-photon imaging. Three dimensional maps of cellular deformation under localized mechanical strain are reported. These measurements indicate that the response of cells to large focal stresses is not always a local deformation.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Variations on QED in three dimensions

Abstract The quantization of three-dimensional electrodynamics in 2 + 2 De Sitter space is carried out in detail. In three dimensions we find five completely different types of quantum electrodynamics. The most interesting versions have spins +1 and/or −1. When both spins are combined as modes of a single vector potential with definite parity, then the field strength vanishes; nevertheless the theory has an infinite space of propagating physical modes. This version of three-dimensional QED is equivalent to three-dimensional singleton theory. The requirements of gauge invariance prohibit local interactions, in the classical theory and within the framework of canonical quantization, and interactions are thus limited to the boundary at spatial infinity, a torus. There are also two chiral theories, in which the physical modes have spin +1 only, or −1 only; here the field strength is not identically zero, though it vanishes on the physical subspace. The chiral theories do not have smooth limits as the curvature tends to zero. All these versions of electrodynamics are smooth limits of massive vector theories, and all can be regarded as quantized counterparts of classical Chern-Simons theory. The most standard form of three-dimensional QED has physical modes with spin zero; it is in a sense a limit of a massive theory with spin zero. In two dimensions the only physical degree of freedom is an excitation with vanishing energy and momentum, a topological mode.
Sometimes a noun is just a noun: comments on Bird, Howard, and Franklin (2000).

Bird, Howard, and Franklin (2000) have proposed a semantic-conceptual explanation of grammatical category-specific deficits that attributes impairments in noun and verb processing to two distinct mechanisms. According to their account, apparent deficits in verb production are not category specific, but rather result from the lower imageability of verbs compared to concrete nouns. Noun deficits are said to result from differences in the distribution of semantic feature types such that damage to sensory features results in disproportionate impairments in naming nouns, especially animate nouns, compared to verbs. However, this hypothesis, which we call the "extended sensory/functional theory" (ESFT), fails on several counts. First, the assumption that representations of living things are more heavily freighted with sensory features than are those of nonliving objects does not have any reliable empirical basis. Second, the ESFT incorrectly predicts associations between deficits in processing sensory features and living things or functional features and nonliving things. Finally, there are numerous cases of patients with grammatical category-specific deficits that do not seem to be consistent with damage at the semantic level. All of this suggests that the ESFT is not a useful model for considering grammatical (or semantic) category-specific deficits.
The Dimensional Stability of Carpets in Installations Part II: Stability to Change in Ambient Humidity

Dimensional stability of floor coverings to.forces encountered under end-use conditions has not been investigated extensively, although problems of wrinkling and puckering of carpets in stretch installations arise frequently. Changes in ambient humidity occur over broad ranges in most buildings; consequently, carpets which are not stable to changes in ambient humidity may be susceptible to puckering. A test procedure based on a method adopted by the British Standards Institution was used to characterize a large number of carpets for dimensional stability to changes in ambient humidity. Several carpet construction characteristics—total weight, pile yarn type, gage, and stitch density—were found to have little relationship to stability to humidity change. Large differences in stability were observed among manufacturers. Tufted carpets having jute backings were found to be less stable than carpets manufactured with synthetic backings.
Hierarchal Modeling of Creep Behavior of SnAg Solder Alloys

In this paper, a microstructure-dependent creep model is developed that accounts for the hierarchal microstructure at multiple length scales. The model considers three distinguishable phases in the solder alloy at two different length scales: at the larger scale Sn dendrites of micrometer size are embedded in a homogeneous eutectic region; at a much smaller length scale the eutectic region consists of submicron size Ag 3 Sn particles embedded in a homogeneous Sn matrix. The model predictions agree well with creep test data of lanthanum doped SnAg solders.
Cytodifferentiation of photoreceptors in larval goldfish: Delayed maturation of rods

This study describes the differentiation of photoreceptors in larval goldfish retina. The earliest photoreceptors to differentiate were cones; 3H-fucose labeled cone but not rod outer segments in larval as well as adult goldfish. All major cone types known to be present in the adult goldfish retina (double cones, long and short single cones) were found in the larval retina by 2 days after hatching. The cones matured rapidly; within a few days they had well-developed outer segments and synaptic pedicles that were smaller, but otherwise similar to those in adults. Rods were slower to mature. Their outer segments were at first short, wide, and misshapen; only as they grew longer and narrower did they become straight and properly aligned. Rod spherules were first seen in fish older than 1 month; immature rods contained perinuclear synaptic ribbons and invaginating processes penetrated the cell body. These results suggest that the influence of rods and cones on visual function in larval goldfish may be quite different from the adult.
Networking-centerpiece of academic computing

The criticality of academic computing in engineering education has become increasingly evident. The Harvey Mudd College engineering program, which emphasizes an interdisciplinary approach to problem solving, wherein the various engineering areas, such as chemical, computer, electrical, mechanical, and structural, use the computer as a common educational tool, is described. The client/server computing model mirrors the Harvey Mudd College interdisciplinary education environment. Specific actions taken in two areas, network development and distributed computing, required for an academic computing environment based on the client/server model are discussed. >
Complete Genome Sequences of Azotobacter vinelandii Wild-Type Strain CA and Tungsten-Tolerant Mutant Strain CA6

We report the complete genome sequences of Azotobacter vinelandii mutant strain CA6 and its parent wild-type strain, CA. When fixing nitrogen, strain CA6 displays slow growth and impaired molybdate uptake, tolerance to tungstates, and production of hydrogen gas, compared to results for strain CA. Comparing these genome sequences may provide a genetic basis for these mutant phenotypes.