cssi/SciSciGPT-SciSciNet huggingface dataset:
Taxes and allowances in a dynamic equilibrium model of urban housing with a size—quality hierarchy

Abstract The paper investigates the effects of an income tax, a property tax, and a housing allowance in the Chicago Prototype Housing Market Model (CPHMM), a dynamic, perfect foresight simulation model of the housing market with a size—quality hierarchy and with multiple household groups. The income tax discriminates against housing conversions with large nonfinancial costs, since these are not deductible. In a perfectly competitive housing market, each housing policy in isolation is distortionary. However, the excess burden of a pair of jointly implemented policies may be less than that for one of the policies in isolation. For some realistic parameter values, a housing allowance aimed at improving the average housing quality consumed by the poor improves efficiency by offsetting part of the deadweight losses of the taxes. The allowance benefits both consumers and landlords in the targeted submarkets, but it hurts landlords on the average by inducing substitution from the non-targeted towards the targeted submarkets.
The coordinate numbers of the falls of the U.S.S.R., Estonia, Latvia Lithuania, and Poland

The coordinate numbers of the falls of the U.S.S.R., Estonia, Latvia, Luthuania, and Poland, taken from our “Catalog of Provisional Coordinate Numbers for the Meteoritic Falls of the World,” are compared, in Tables 1 and 2, with the coordinate numbers derived from the longitudes and latitudes as given by E. L. Krinov for 112 of the 113 falls appearing in his “Short Catalog of the U.S.S.R. Meteorites” (1945). Six (6) falls listed by Krinov, but not found in the catalogs of Coulson, Hey, and Leonard, are enumerated in Table 3, while 14 falls not listed by Krinov, but included in our catalog, are inventoried in Table 4. The data of Tables 1 and 2 are commented on briefly.
Proposed High Performance Refrigeration Cycles to Obtain Superconducting Operation of a Two-Mile Linear Accelerator at 1.85K, 1.425K, or 1.0K

The existing two-mile linear electron accelerator at SLAC has a duty cycle of less than 0.1% and is limited to 20 GeV. If it were converted to superconducting operation, the duty cycles might be 100% at 20 GeV and 6% at 100 GeV. This paper discusses high performance refrigeration cycles as necessary to make superconducting operation of a two-mile linear accelerator most reliable and least costly.
Expert and Consumer Evaluation of Patient Medication Leaflets Provided in U.S. Pharmacies

ABSTRACT Objective Evaluate the distribution and quality of patient medication leaflets provided in U.S. pharmacies. Design Observational. Setting United States. Participants 384 randomly selected community pharmacies in 44 states. Interventions Professional shoppers (acting as patients) presented four new prescriptions to study pharmacies. Main Outcome Measures Medication leaflets obtained by shoppers were evaluated by expert and consumer raters using criteria specified in federal law mandating distribution of useful written information to 95% of individuals receiving new prescriptions by 2006. Results Leaflets were provided by pharmacies with 89% of 1,536 prescriptions presented by professional shoppers posing as patients. Leaflet quality varied: 95% of leaflets received high ratings on accuracy, but only 19% received high ratings on the specificity of directions. Fewer than 10% of all leaflets met quality criteria regarding contraindications, precautions, and how to avoid harm. One fourth of all leaflets had poor print size, according to the shoppers. Conclusion Additional efforts are needed to meet federally mandated information distribution and quality goals by 2006.
Steps toward nationhood: Henry Laurens (1724–92) and the American Revolution in the South*

Henry Laurens's political career ranks among the South's crucial contributions to the Revolution and American nationhood, contributions that historians have largely neglected. This article attempts to estimate this Southern role through an examination of Laurens's life and letters, and the political culture of his home state, South Carolina. Laurens and others in the South, despite an incongruous commitment to slavery, gave the emerging nation a distinctly Southern stamp by advocating state federalism, the sovereignty of the people through democratic legislature, and a strong executive.
Gene Silencing in Cancer in Association with Promoter Hypermethylation

This article reviews the mechanisms of gene silencing in cancer and clinical applications of this phenomenon. The silencing of genes, especially tumor-suppressor genes, is a key event in the development of cancer. The silencing can be effected by a disabling mutation or by a shutting down of the promoter region, the site at which transcription of the gene begins.
Serotonin-transporter Polymorphism Pharmacogenetics in Diarrhea-Predominant Irritable Bowel Syndrome

Background & aims A serotonin (5-HT)(3) receptor antagonist relieves symptoms in women with diarrhea-predominant irritable bowel syndrome (D-IBS). 5-HT undergoes reuptake by a transporter protein (SERT). Polymorphisms in the promoter for synthesis of SERT (SERT-P) influence response to serotonergic medications in depression. Our hypothesis is that polymorphisms of the promoter region for the SERT influence colonic transit in response to treatment with alosetron in D-IBS. Methods Thirty patients (15 men, 15 women) with D-IBS received 1 mg twice a day alosetron for 6 weeks; colonic transit was measured by scintigraphy at baseline and at the end of treatment. Twenty-three patients consented to provide blood DNA samples. Long, short, and heterozygous SERT polymorphisms were identified by polymerase chain reaction-based restriction fragment length polymorphisms and confirmed by direct sequencing. We sought pharmacogenomic association of long, short, and heterozygote polymorphisms with a change in colonic transit and with an a priori-defined, clinically meaningful change in transit at 24 hours (>1.1 colonic regions). Results SERT polymorphisms tended to be associated with colonic transit response (P = 0.075); there was a greater response in those with long homozygous than heterozygous polymorphisms (P = 0.039). Slowing of transit by >1.1 colonic region was observed in 9 women and 3 men and was more frequent in long homozygous than heterozygous patients (P = 0.024). Age, gender, and duration of IBS were not significantly different in the 3 groups. Conclusions Genetic polymorphisms at the SERT promoter influence response to a 5-HT(3) antagonist in D-IBS and may influence benefit-risk ratio with this class of compounds.
Comparisons of Phosphate, Carbohydrate, and Kjeldahl Nitrogen Content of Normal and Xantha Mutant Leaves of Helianthus annuus

Tissues of the xantha mutant of Helianthus annuus have an abnormally high phosphorus content compared to normally pigmented tissues of comparable age and position on the plant. A major portion of the observed differences can be accounted for in the acid-insoluble “7-minute” phosphate fraction, a fraction thought to be composed primarily of polyphosphates. Although this suggests that the xantha mutant may possess a mechanism for immobilizing excess phosphates as insoluble polymers, all qualitative tests for polyphosphates in extracts of mutant leaves have been negative. Carbohydrate levels in the mutant are lower than in wild type leaves due to the absence of photosynthesis in the mutant and its inability to form starch. Differences between mutant and wild type in Kjeldahl nitrogen appear to be a consequence of aging effects resulting from propagation by grafting onto physiologically older stocks.
Active-Learning Exercises to Teach Drug-Receptor Interactions in a Medicinal Chemistry Course

Objective. To incorporate structural biology, enzyme kinetics, and visualization of protein structures in a medicinal chemistry course to teach fundamental concepts of drug design and principles of drug action. Design. Pedagogy for active learning was incorporated via hands-on experience with visualization software for drug-receptor interactions and concurrent laboratory sessions. Learning methods included use of clicker technology, in-class assignments, and analogies. Assessment. Quizzes and tests that included multiple-choice and open-ended items based on Bloom's taxonomy were used to assess learning. Student feedback, classroom exercises, and tests were used to assess teaching methods and effectiveness in meeting learning outcomes. Conclusion. The addition of active-learning activities increased students' understanding of fundamental medicinal chemistry concepts such as ionization state of molecules, enzyme kinetics, and the significance of protein structure in drug design.
Perceptual contributions of the consonant-vowel boundary to sentence intelligibility.

Although research has focused on the perceptual contribution of consonants to spoken syllable or word intelligibility, in sentences vowels have a distinct perceptual advantage over consonants in determining intelligibility [Kewley-Port et al., J. Acoust. Soc. Am. 122, 2365–2375 (2007)]. The current study used a noise replacement paradigm to investigate how perceptual contributions of consonants and vowels are mediated by transitional information at segmental boundaries. The speech signal preserved between replacements is defined as a glimpse window. In the first experiment, glimpse windows contained proportional amounts of transitional boundary information that was either added to consonants or deleted from vowels. Results replicated a two-to-one vowel advantage for intelligibility at the traditional consonant-vowel boundary and suggest that vowel contributions remain robust against proportional deletions of the signal. The second experiment examined the combined effect of random glimpse windows not locked to segments and the distributions of durations measured from the consonant versus vowel glimpses observed in Experiment 1. Results demonstrated that, for random glimpses, the cumulative sentence duration glimpsed was an excellent predictor of performance. Comparisons across experiments confirmed that higher proportions of vowel information within glimpses yielded the highest sentence intelligibility.
13C- and 15N-Labeled Peptide Substrates as Mechanistic Probes of Oligosaccharyltransferase†

The carboxamide moiety that links the carbohydrate and protein moieties in N-linked glycoproteins has been unambiguously determined to arise intact from asparagine by the use of chemically synthesized Bz-[4-13C, 15N]Asn-Leu-Thr-NH2 as an oligosaccharyltransferase (OST) substrate. Bz-[4-13C]Asn-Leu-Thr-NH2 was also synthesized and used to evaluate a proposed mechanism of OST catalysis similar to that of glutamine-dependent amidotransferases using 15NH4OAc as a potential external nucleophile. Analysis of NMR and MS spectra of the isotopically labeled peptides and the resulting biosynthesized glycopeptides indicates that free 15NH3 is not lost from the doubly labeled substrate during catalysis nor can exogenous 15NH3 intercept any of several postulated enzyme-bound species. These results indicate that OST-catalyzed glycosylation does not follow a mechanism involving the transient generation of exchangeable "NH3". Thus, in contrast to several glutamine-dependent amidotransferases, OST catalysis does not lead to transient scission of the asparagine beta-carboxamide C-N bond. Together with previously published results, these data argue against nucleophilic activation of the asparagine beta-carboxamide moiety being the underlying chemical mechanism for OST-catalyzed glycosylation of peptides.
Plate tectonic models for Indian Ocean “intraplate” deformation

Abstract The equatorial region of the conventionally defined Indo-Australian plate has long been recognized as containing a type example of intense “intraplate” deformation. We trace the development of tectonic models for the area to illustrate techniques for the analysis of such deformation. The identification of anomalous seismicity near the Ninetyeast and Chagos-Laccadive Ridges demonstrated the existence of the deformation. Focal mechanisms from recent and historic earthquakes showed strike-slip motion occurring along the Ninetyeast Ridge; seismic moment data allowed the rate to be estimated. Similar studies showed north-south tension in the Chagos Bank region and north-south compression in the region between the Ninetyeast and Chagos ridges. Global plate motion studies indicated non-closure of the Indian Ocean triple junction, suggesting the conventional plate geometry was inadequate for a rigid plate description of the area. Gravity and marine geophysical data indicated intense north-south compressional deformation south of the Bay of Bengal. These observations are reconciled by a plate motion model in which Australia and India lie on distinct plates divided by a boundary that intersects the Central Indian Ridge near the equator. In this model Arabia, usually considered a separate plate, has negligible motion relative to India. The resulting Euler vector for Australia relative to Indo-Arabia lies just east of the Central Indian Ridge, and predicts approximately 0.5–1.5 cm/yr compression in the Central Indian Basin and 1.5–2 cm/yr strike-slip motion along the northern Ninetyeast Ridge, consistent with the seismological and geophysical data. In contrast to conventional oceanic plate boundaries, the boundary deformation is distributed over a wide zone. This diffuse nature may reflect either the boundary's recent inception or slow rate of motion. Analysis of seismicity and deformation in the boundary zone should offer insights into the mechanics of its development and its implications for the evolution of plate boundaries.
Fabrication issues of oxide-confined VCSELs

To insert high-performance oxide-confined vertical-cavity surface- emitting lasers (VCSELs) into the manufacturing arena, we have examined the critical parameters that must be controlled to establish a repeatable and uniform wet thermal oxidation process for AlGaAs. These parameters include the AlAs mole fraction, sample temperature, carrier gas flow, and bubbler water temperature. Knowledge of these parameters has enable the compilation of oxidation rate data for AlGaAs which exhibits an Arrhenius rate dependence. The compositionally dependent activation energies for Al{sub x}Ga{sub 1-x}As layers of x=1.00, 0.98, and 0.92 are found to be 1.24, 1.75, and 1.88 eV, respectively. 7 figs, 1 tab, 14 refs.
Effect of ingested gossypol on the growth performance of rats.

Das Wachtum von Ratten, deren Nahrung einen reichen und freien Gossypolgehalt mit Qualitatsprotein enthielt, wurde untersucht. Die wachtumshemmende Wirkung des Gossypols konnte teilweise durch Erhohung des Eiweissgehaltes in der Nahrung kompensiert werden.
Minkowski Sums of Periodic Surface Models

Recently we proposed a periodic surface model to assist geometric construction in computer-aided nano-design. This implicit surface model helps create super-porous nano structures parametrically and support crystal packing. In this paper, we study construction methods of Minkowski sums for periodic surfaces. A numerical approximation approach based on the Chebyshev polynomials is developed and can be applied in both surface normal direction matching and volume translation formulations.Copyright © 2009 by ASME
A new Amplatzer device to maintain patency of Fontan fenestrations and atrial septal defects.

This study evaluated use of Amplatzer fenestrated device to maintain patency of the Fontan fenestration and atrial septal defect. Fenestrations are routinely created in patients with lateral tunnel or extracardiac Fontan. Spontaneous closure of the fenestration can lead to Fontan circulation failure. Other patients without single-ventricle physiology may benefit from a small communication between the left and right atria for decompression if closure of the atrial septal defect leads to failure of a dysfunctional ventricle. Amplatzer septal occluder device was modified to create a fenestration through the disks. Three patients with modified Fontan and one patient with a large atrial septal defect underwent placement of the device by transcatheter technique. The device deployment was guided by transesophageal echocardiography. The procedure was successful in all patients. Contrast injection after placement revealed patent fenestration with free flow. Follow-up ranged from 3 months to 1 year. All devices were patent by transthoracic echocardiography. These preliminary results suggest that the Amplatzer fenestrated device can serve as a valuable tool in failing Fontan circulation and may help to avoid surgical intervention. More studies are needed to assess long-term efficacy of the device.
Microvasculature network identification in 3-D fluorescent microscopy images

Segmentation of noisy and low-resolution images of microvasculature from 3-D fluorescence microscopy has been proven a challenging task. In this paper, we propose an approach to identify the global connectivity structure in a microvasculature network, which can be of use in obtaining more detailed segmentation results and for comparing and validating other network segmentation methods. Our approach begins with determining a collection of potential vessel junctions. Thinking of the junctions as vertices in a graph modeling connectivity of the vasculature network, we formulate and solve an integer linear programming problem based on a novel image-derived utility function to remove false junctions from the previously identified set and determine the network structure of remaining junctions. The scheme is demonstrated to be robust and computationally tractable making it well suited for use in high-throughput applications. Quantitative validations demonstrating high rate of sensitivity are given.
Simple method for rapid removal of rat spinal cord

A simple method for rapid removal of the rat spinal cord is described. Basically one removes segments of the spinal column with a pair of scissors and then extrudes the spinal cord with a wooden dowel.
Effect of acetylcholine and GABA on the transfer function of electromotility in isolated outer hair cells

Outer hair cells (OHC) from high- and low-frequency regions were separately isolated from guinea pig cochleas. The cells were inserted with their ciliary pole first into a partitioning microchamber so that only 20-50% of the cell length was excluded. Somatic length changes due to transcellular electrical stimulation were measured at the cuticular plate in the inserted portion of the cells. Transfer curves of electromotility of the OHCs were obtained by both a series of brief (2.5 ms) and longer (30 ms) square pulses with opposite polarity and linearly increasing size from 40 to 280 mV in both negative and positive directions. Alterations in the transient and steady-state electromotility transfer curves were examined by application of acetylcholine (ACh) and gamma-aminobutyric acid (GABA) to the synaptic pole. ACh, in the concentration range of 10-30 microM, evoked a significant magnitude and gain increase of electromotility in both transient and steady-state responses without a measurable shift in the operating point of the displacement-voltage transfer curve. A tonotopic response magnitude difference is found for ACh challenge. Basal turn OHCs responded with greater magnitude increase (+90% increase from control) than apical turn OHCs (+40%). GABA exerted an opposite effect, again in a location-dependent manner. Magnitude response decreased about 30% for long cells and 14% for short ones. Atropin, a muscarinic receptor antagonist, completely blocked the increase in electromotility response due to ACh. However, D-tubocurarine, a nicorinic receptor antagonist, while not blocking the ACh effect, altered the cell's apparent operating point. Bicuculline methiodide, a GABAA-receptor antagonist, completely arrested GABA influences on the electromotility response. These results suggest that both ACh and GABA can change the electromotile activity of OHCs, in a tonotopically biased manner. ACh challenge evokes greater magnitude responses in basal turn OHCs, whereas GABA induces greater motility response decrease in apical turn OHCs. The control of the gain and magnitude of electromotility by the transmitter substances appear to involve at least two mechanisms. One is probably related to conformational changes of the voltage-to-movement converter molecules and a change in their number in an effective operational pool, the other operates via changing the electrical resistance of the basolateral cell membrane.
How many systems make a global array

Stoffregen & Bardy suggest that the global array provides the specification that is lacking when senses are considered in isolation. This seems to beg the question of the minimum number of senses in a global array. Individuals with sensory loss manage with fewer senses, and humans manage with fewer than electric fish; so specification, if it exists, cannot require all possible senses.
Loneliness, Internalized Homophobia, and Compulsive Internet Use: Factors Associated with Sexual Risk Behavior among a Sample of Adolescent Males Seeking Services at a Community LGBT Center

This study examined a modified version of the Loneliness and Sexual Risk Model (LSRM), which predicts that sexual risk behavior results in part from a link between loneliness and compulsivity. A convenience sample of 49 adolescent males (ages 14 to 19) seeking services at a Lesbian, Gay, Bisexual, and Transgender (LGBT) Community Center completed a cross-sectional survey that included questions on loneliness, internalized homophobia, and compulsive Internet use. Descriptive, correlational, and regression analyses were conducted. Participants reported a range (0–40) of sexual partners in the past year. Compulsive Internet use was positively and significantly associated with both loneliness and internalized homophobia. A negative binomial regression analysis found that greater feelings of loneliness, less Internet use, and greater homophobia were associated with more sexual partners in the past year. The results provide partial support for the LSRM in adolescents. Implications for prevention and interventio...
Four-Year-Olds′ Disambiguation of Action and Object Word Reference

Preschool-age children show a very strong tendency to map a novel noun onto an unfamiliar rather than a familiar object. This so-called disambiguation effect has been interpreted as evidence that youngers expect object labels to be mutually exclusive. In Experiment 1, 4-year-olds were observed to map a novel verb onto an unfamiliar action about twice as often as they mapped it onto a familiar one. When the unfamiliar action had been preexposed, but the familiar one had not, the mapping preference was eliminated. In Experiment 2, 4-year-olds mapped a novel noun onto an unfamiliar object about five times as often as they mapped it onto a familiar object, and this tendency was not affected by preexposure. Even when action embedding and question complexity were controlled, the disambiguation effect was stronger for object than for action words. An account is presented in which two lexical principles, Mutual Exclusivity and Feeling of Novelty, are hypothesized to apply differently to action than to object words.
Colour-and-Forward: Relaying “what the destination needs” in the zero-error primitive relay channel

Zero-error communication over a primitive relay channel is for the first time proposed and studied. This model is used to highlight how one may exploit the channel structure to design a relaying strategy that explicitly provides “what destination needs”. We propose the Colour-and-Forward relaying scheme which constructs a graph G R of relay outputs based on the joint conditional distribution of the relay and destination outputs given the channel input. The colours of this graph G R are sent over the out-of-band link in the primitive relay channel and are shown to be information lossless in the zero-error sense; they result in the same confusability graph as if the destination had the relay's received signal. This allows us to obtain an achievable zero-error communication rate for the primitive relay channel, which may be shown to be capacity for a class of channels.
High-pressure shock tube studies on carbon oxidation reactions with carbon dioxide and water

The heterogeneous reactions of solid carbon reacting with gaseous carbon dioxide and steam have been studied under high-pressure and high-temperature conditions. The high-pressure shock tube facili...
The modulation of reward priority by top-down knowledge

Reward-associated features capture attention automatically and continue to do so even when the reward contingencies are removed. This profile has led to the hypothesis that rewards belong to a separate class of attentional biases that is neither typically top-down nor bottom-up. The goal of these experiments was to understand the degree to which top-down knowledge can modulate value-driven attentional capture within (a) the timecourse of a single trial and (b) when the reward contingencies change explicitly over trials. The results suggested that top-down knowledge does not affect the size of value-driven attentional capture within a single trial. There were clear top-down modulations in the magnitude of value-driven capture when reward contingencies explicitly changed, but the original reward associations continued to have a persistent bias on attention. These results contribute to a growing body of evidence that reward associations bias attention through mechanisms separate from other top-down and botto...
New atheism and moral theory

Over the past decade, New Atheists have campaigned against the influence of religion in public life and favored a more enlightened understanding of the world – one based on the methods and theories of the natural sciences. Although the leaders of this movement refuse to give religion, even moderate religion, any place in determining moral conduct, they offer few alternatives. Most define moral responsibility by referring to facts about human biology or natural moral intuitions, yet without adequately defending this or exploring the possibilities of non-naturalistic secular moralities. This essay argues that New Atheists' moral theories tend to be weak because of their naturalist assumptions. Its leading proponents seem to be unwilling to acknowledge that moral philosophy can play a role in developing secular moral precepts because philosophy fails to meet their strong criteria of scientific validity. This position is misguided not only because it has led New Atheists to defend weak moral theories but also...
Discharge Efficiency of Reservoir-Application-Specific Labyrinth Weirs

AbstractPublished labyrinth weir design methods, which have primarily been developed on the basis of labyrinth weir test data from laboratory flumes, are specific to in-channel labyrinth weir applications in which the approach flow is oriented normal to the weir axis. Consequently, some uncertainty exists regarding the hydraulic performance of labyrinth weir configurations that are specific to reservoir applications (i.e., projecting, flush, rounded inlet, and arced labyrinth weirs). The discharge efficiency, as characterized by the weir discharge coefficient, of laboratory-scale projecting, flush, rounded inlet, and arced labyrinth weirs with 12 degree sidewall angles, were evaluated as a function of HT/P and compared with in-channel labyrinth weir discharge efficiencies. The arced labyrinth weir configuration had a higher discharge efficiency (∼5 –11% higher than an in-channel labyrinth weir orientation). In general, the projecting, flush, and rounded inlet orientations were less efficient than the in...
Time-interval measurement of stuttering: effects of interval duration

The study reported in this article used a binary forced-choice judgment procedure to investigate the effects of sample duration on observers' judgements of stuttering. Two groups of judges, differing in their previous experience with stuttering, categorized 270 speech intervals as stuttered or nonstuttered; the intervals were drawn from 30 persons who stuttered and ranged from 1 sec to 15 sec in duration. Results showed that judgments were consistently related to interval duration, with shorter intervals significantly more likely than longer intervals to be labeled nonstuttered. Interjudge agreement levels, however, were largely unaffected by the different interval durations for most speakers and for both judge groups, with the exception of the longest and shortest intervals drawn from speakers evidencing the mildest and most severe stuttering. An interval duration in the 3- to 5-sec region appeared to attract the most satisfactory level of agreement. The implications of these findings for interval-based clinical and experimental measurements of stuttering are discussed.
Stress ventricular function test in conscious, nonthoracotomised dogs to assess cardiac drug efficacy

The measurement of left ventricular (LV) function is frequently performed in unconscious or thoracotomised animals in the resting state; these conditions may seriously affect the basal haemodynamic state. To assess myocardial function in conscious animals, a technique was developed to place a catheter across the atrial septum into the left ventricle without a thoracotomy. A stress ventricular function test (SVFT) was performed by raising the systemic blood pressure with methoxamine in the conscious dog. In order to demonstrate the effectiveness of the SVFT in the detection of a decrease in ventricular function, a SVFT was performed before and after the acute infusion of verapamil to determine resting and reserve LV function. A slope relating systolic aortic pressure to the LV end-diastolic pressure was obtained in 10 dogs using a low dose (0.005) and in four dogs a high dose (0.01 μg·kg−1·min−1) verapamil (V). The mean slope before V was 3.6±1.2 and after 2.0±0.92 (p<0.001). The day-to-day variability of the SVFT was less than 22% (coefficient of variability). The SVFT is a sensitive, reproducible method to assess resting and increased or decreased myocardial contractility and is useful in selecting appropriate doses of cardiac drugs to determine their effect on the myocardium during acute and chronic infusion studies in the conscious, nonthoracotomised dog.
Application of ridge regression to quantify marginal effects of collinear soil properties on phytotoxicity of arsenic, cadmium, lead, and zinc

Soil properties that mitigate hazardous effects of environmental contaminants through soil chemical sequestration should be considered when evaluating ecological risk from terrestrial contamination. The objective of this research was to identify predominant soil chemical/physical properties that modify phytoaccumulation of As, Cd, Pb, and Zn to the non-hyperaccumulating higher plants: Alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne L.), and Japanese millet (Echinochloa crusgalli L.). Transmission coefficients were estimated from a dose–response experiment with the use of aboveground tissue contaminant concentrations and correlated with selected soil property measurements to develop statistical prediction models for soil-specific adjustments to ecological risk assessments. Significant correlations between soil properties and transmission coefficients were observed for all four contaminants. Intercorrelation was also observed among soil properties, including cation exchange capacity (CEC) and soil pH (p = 0.035), CEC and total clay (p = 0.030), organic carbon (OC) and total clay content (p = 0.085), reactive iron oxides (FeOX) and OC (p = 0.078), and reactive Mn oxide (MnOX) and total clay content (p < 0.001). Ridge regression, a technique that suppresses the effects of multicollinearity and enables prediction, was used to assess the marginal contributions of soil properties found to mitigate phytoaccumulation. Prediction models were developed for all four contaminants. Significant variables were FeOX for As or pH, OC, CEC, clay content, or a combination of factors for cationic metal models. Ridge regression provides a powerful alternative to conventional multiple regression techniques for ecotoxicological studies when intercorrelated predictors are experimentally unavoidable, as with soil properties.
Liver transplantation for hepatocellular carcinoma

Hepatocellular carcinoma can only be cured by physical removal or destruction of the tumor before it has spread. This can be accomplished by the ablation of the tumor, surgical resection of the tumor-bearing liver, or by liver transplantation. Ablation and resection can only be performed in patients who will be left with sufficient liver volume to sustain normal hepatic function. Unfortunately, the same disease that caused the HCC also limits the amount of parenchymal loss that can be tolerated by the patient. Liver transplantation is an appealing treatment option because it has the potential to cure patient of both the cancer and the predisposinig liver disease. Excellent survival rates are possible in patients with early HCC who receive a transplant, but dismal results are seen when patients with advanced tumors are transplanted.Wide criteria for transplant allow for more patients to be cured of HCC, but this comes at the expense of a greater overall recurrence rate. The acceptable recurrence rate is not a concrete number, but this is a function of donor organ availability. A 50% cure rate is viewed as an excellent outcome for many accepted cancer operations; however, in the case of transplant for HCC, this would represent a poor use of the scarce donor resource when the same liver offers a 70% 5-year survival rate to a non-HCC patient. These issues and methods retarding tumor progression while on the transplant waiting list are reviewed herein.
Does a Contralateral Carotid Occlusion Adversely Impact Carotid Artery Stenting Outcomes

Background Carotid artery stenting (CAS) has grown as a possible alternative for the treatment of extracranial cerebrovascular disease in the past decade. A preexisting contralateral carotid artery occlusion has been described as a risk factor for inferior outcomes after carotid endarterectomy, but its impact on CAS outcomes is less understood. Methods A retrospective review of 417 CAS procedures performed between May 2001 and July 2010 at a single center using self-expanding nitinol stents and mechanical embolic protection devices was conducted. Patients were divided into two groups, those with a preexisting contralateral carotid occlusion (group A, n = 39) versus those without a contralateral occlusion (group B, n = 378). Patient demographics and comorbidities as well as 30-day and late death, stroke, and myocardial infarction (MI) rates were analyzed. Mean follow-up was 4 years (range: 0-9.4 years). Results Overall, mean age of the 314 men and 103 women was 70.5 years. In group A, there were two (5.1%) octogenarians and nine patients (23.1%) with symptomatic disease as compared with group B with 53 (14%) octogenarians and 121 (32%) patients with symptomatic disease. The overall 30-day death, stroke, and MI rates were 0.5%, 1.9%, and 0.7%, respectively. When comparing group A with group B, these results were not significantly different: death (0% vs. 0.5%), stroke (2.6% vs. 1.9%), and MI (0% vs. 0.8%). Long-term outcomes for groups A and B were also not significantly different: death (25.6% vs. 22.2%), stroke (5.3% vs. 3.4%), and MI (15.4% vs. 14%) (p = nonsignificant). Conclusion A preexisting contralateral carotid artery occlusion does not seem to adversely impact CAS outcomes.
The Significance of the History of Goiter for the Etiology of the Disease

T HIS DISCUSSION 15 concerned with endemic goiter. Tumors of the thyroid may be expected to occur about as frequently as do tumors of other organs. However, thyroid tumors occur much more frequently and this prevalence is conspicuous in certain regions. In many places, endemic goiter appeared quite recently and its subsequent history resembled that of a newly introduced infectious disease. I am not so naive as to believe that absence of mention means absence of the disease. Only when the description of a population is so detailed as to physique, diseases and medical practices as to make it almost certain that goiter, if present, would have been recorded, do I regard the absence of such mention as an indication of absence. In a few instances, definite statements that the disease was not present, or had not been present until a comparatively short time earlier, are made. It is impossible to review all the work of fifteen years in this report; only a few instances can be discussed.t In contrast to the prolonged controversy over the pre-Columbian existence of syphilis, the question of the presence of goiter in the Americas attracted no attention until I raised it. This neglect seems to have been due to two factors. The first was the general acceptance of the view that the disorder was due to some factor in the environment, which was supposed
Sequential logic synthesis for testability using register-transfer level descriptions

A synthesis-for-testability approach that uses a register-transfer level (RTL) specification of a sequential circuit to derive a fully testable implementation of the circuit is presented. Emphasis is placed on the development of a synthesis strategy of don t care exploitation and logic partitioning that results in a fully testable implementation of the sequential machine. Preliminary experimental results indicate that large sequential circuits (e.g., finite-state-machine controllers, data paths) with a large number of latches and gates can be synthesized to be fully nonscan testable by use of these techniques. >
A muscular double helix in Gastrotricha

Abstract Studies on the muscular system of gastrotrichs revealed a new muscle arrangement. Helicoidal muscles, in right- and left-hand spirals, were found in all 9 species of Gastrotricha examined. The macrodasyidans Acanthodasys aculeatus , Tetranchyroderma papii and Thaumastoderma heideri had helicoidal muscles along the entire digestive tract (pharynx and intestine), whereas Macrodasys caudatus and Turbanella cornuta displayed helicoidal muscles mainly along the pharynx. Representatives of the order Chaetonotida, Chaetonotus aculifer , Draculiciteria tessalata, Lepidodermella squamata , and Xenotrichula intermedia , all had helicoidal muscles on the intestine, while pharyngeal helicoidal muscles were not observed in C. aculifer or L. squamata . Helicoidal muscles are the thinnest-diameter muscles in the gastrotrich body and generally surround splanchnic circular muscles and longitudinal bands. The proposed functions of helicoidal muscles include antagonization of radial dilations of the digestive tract during feeding, pressurization of the intestine and closure of the pharyngeal-intestinal valve in chaetonotidans, and prevention of intestinal kinking during changes in body shape. The presence of this unique muscle orientation may be a synapomorphy for Gastrotricha.
The Laminar Structure of the Atmosphere and its Relation to the Concept of a Tropopause.

The concept of a tropopause as a discontinuity surface, single or multiple, is shown to be a misleading oversimplification. It is misleading with respect to the actual thermal structure of the atmosphere and the exchange process or transport from troposphere to stratosphere. Original radiosonde records, reprocessed to preserve the observational details indicate many zones of large hydrostatic stability often separated by zones of neutral stability. By coordinating the analyses of vertical cross sections, isentropic charts and isentropic trajectories it was found that these zones of large stability have spatial and temporal continuity. (They have been called stable laminae to emphasize their large quasi horizontal extent and small vertical dimension.) The upper and lower boundaries of the laminae are characterized by a rapid variation in stability that may be considered discontinuous. These discontinuity surfaces, however, coincide with isentropic surfaces and extend from the stratosphere into the troposphere. Consequently there is no barrier to quasi horizontal flow, i. e., no barrier to flow from stratosphere to troposphere and vice versa with attendant transfer of heat, moisture and radioactive contaminants. It is proposed that the tropopause be defined in terms of large scale average thermal properties calculated from the detailed soundings by a weighted running mean. The tropopause is defined as a barotropic surface, not a discontinuity surface, above which the average stability is large and the average baroclinity negative and below which the average stability is small and the average baroclinity is positive. On the soundings this represents the envelope that joins the smoothed soundings and in space the highest elevation reached by the isentropic surfaces in the potential temperature range enclosed by the envelope.
Decreased platelet vitamin C in diabetes mellitus: possible role in hyperaggregation.

Abstract To determine whether the handling of Vitamin C in the diabetic might be altered and might relate to the increased platelet sensitivity, we have investigated levels of platelet Vitamin C in the diabetic and determined the effects of Vitamin C in vitro or in vivo on platelet aggregation. Levels of ascorbic acid, as tested by a lingual method, were significantly lower in diabetics than in normals (p in vitro were studied by adding ascorbic acid in buffered solution (pH 7. 35) prior to aggregating agents. Ascorbic acid (1000 μg/ml) in platelet-rich plasma consistently inhibited platelet aggregation with threshold concentrations of ADP, epinephrine, and collagen, but enhanced aggregation with arachidonic acid. With washed platelets, ascorbic acid inhibited arachidonic acid-induced aggregation. To rule out an interaction of ascorbic acid and arachidonic acid in the medium, platelets were incubated at 37°C for 10 minutes with varying concentrations of ascorbic acid, rewashed, and aggregation with arachidonic acid tested. Aggregation was inhibited in a linear dose-dependent fashion. Oral ingestion of ascorbic acid (2 gm/day) for seven days by normal non-smoking males produced a marked inhibition of aggregation. In a similar study, platelets from an insulin-dependent diabetic showed no change in aggregation. These results suggest that platelet levels of ascorbic acid may relate to the hyper-aggregation of platelets from diabetics.
A review of the CITES listing of big-leaf mahogany

Big-leaf mahogany Swietenia macrophylla King (Meliaceae) is the premier timber species of Latin America. A lack of law enforcement allows widespread illegal logging, and its unsustainable harvest depletes local stocks, necessitating a shift in sources of supply. To better control this exploitation, parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) recently elected to list mahogany on Appendix II. This listing requires exporting countries to verify that each shipment was legally acquired and its harvest was non-detrimental to the survival of mahogany. The CITES listing poses considerable challenges: 1) there is no precedent, as mahogany is the first commonly traded timber species listed on Appendix II, and 2) given current, unsustainable logging practices, CITES regulations will be difficult to implement. This paper synthesizes information on the conservation and management of mahogany that informed the listing decision, and provides recommendations for implementation, including timber tracking to ensure legality.
Pressure-induced myogenic tone and role of 20-HETE in mediating autoregulation of cerebral blood flow

While myogenic force in response to a changing arterial pressure has been described early in the 20th century, it was not until 1984 that the effect of a sequential increase in intraluminal pressur...
Top-down composite modeling of bulk power systems

A top-down modeling methodology is proposed as a tool to evaluate the composite reliability performance of a bulk power system. Applications to understanding reliability tradeoffs are examined. Directions for future research are discussed.
Bismuth subsalicylate tablet masquerading as vanishing button battery in the stomach.

We read with interest the article by Walker and Caldera highlighting the corrosive effects of button battery (BB) ingestion on the GI tract. The American Society for Gastrointestinal Endoscopy guidelines recommend its prompt removal if it is present in the esophagus or if it is retained in the stomach for more than 48 hours. We report a case of a 22-year-old man evaluated in our emergency department for upper abdominal pain. A CT scan showed a radiopaque 18-mm disk-like object in the gastric fundus (Fig. 1), resembling a BB. The patient could not recollect any accidental ingestion, and although the suspected BB had passed into the stomach, the duration of its ingestion could not be confirmed. Upper endoscopy showed food debris mixed with pink material in the gastric fundus, but no foreign body was found in the stomach or duodenum. Immediate followup abdominal x-ray also did not show a residual foreign body. Upon repeated questioning, the patient finally mentioned taking a Pepto-Bismol tablet (Procter & Gamble, Cincinnati, Ohio, USA) for his upset stomach before presentation to the ED. It is likely that the radiopaque disk seen on CT was the Pepto-Bismol tablet, and as the tablet dissolved, only some pink material was left in the stomach seen on endoscopy, leading to the “vanishing of the BB.” Most medications are not radiopaque; however, some metallic compounds, including barium, lead, arsenic, bismuth, thorium, and iodine, are sufficiently opaque to be seen on routine imaging. Bismuth subsalicylate, the active ingredient in Pepto-Bismol, is radiopaque in its pill form but not in its liquid form because of dilution. This rarely known phenomenon is important to consider in the evaluation of a radiopaque object in the GI tract, where it can mimic the appearance of a BB performing a vanishing act.