cssi/SciSciGPT-SciSciNet huggingface dataset:
Emotional stress and sudden death--the role of cathecholaminergic polymorphic ventricular tachycardia.

I read with interest the review of sudden death after emotional stress by Appels and Bolk [1]. In their review, they discuss the role of the sympathetic nervous system in acute sudden death. They, however, fail to discuss the role of cathecholaminergic polymorphic ventricular tachycardia (CPVT). CPVT is a recently characterized inherited disorder which presents with stress-induced or exercise induced ventricular tachycardias and is associated with syncope and sudden cardiac death. It is thought to be linked to mutations of the gene coding for the cardiac Ryanodine Receptor (RYR2) and the calsequestrin (CASQ2) gene [2]. In these patients, it seems that adrenergic stimulation triggers the typical bidirectional broad complex ventricular tachycardia by causing diastolic depolarizations in association with excessive release of calcium from the sarcoplasmic reticulum. This condition was initially thought to be limited to the
Symmetric multi-valued logic functions: characterization and synthesis

The characteristics of symmetric functions in a multi-valued logic algebra system are studied. A modular synthesis approach for realizing symmetric functions is proposed. The approach is particularly useful when the number of arguments of the function to be synthesized is large. The necessary and sufficient conditions for a function to be symmetric in the multi-valued logic algebra system are presented, and a way to test the symmetricality of a given function is also outlined.
Quantitative footprinting analysis of the chromomycin A3--DNA interaction.

Quantitative footprinting methods have been used to measure site-specific binding constants for the anticancer drug actinomycin D on a restriction fragment from pBR 322 DNA. Sites with the highest binding constants, 1–6 x 105M-1, possess the classical binding sequence GC, which is flanked on the 5’ side by either T or C, but not G. The sequence GGC is a weaker binding site, except for one case. A non-classical sequence, CGTC, was found to be a strong actinomycin D site. However, the value of the binding constant for this site and for other classical sites was dependent on the proximity of sites on the 139-mer and/or the nature of flanking sequences. Comparison with earlier studies indicates that the length of DNA may be important, with short oligomers yielding higher binding constants than polymeric DNA. The analysis also revealed that actinomycin D can cause anomalous rate enhancements adjacent to certain of its interaction sites when binding is probed with DNase I and the metalloporphyrin, MnT4MPyP, but not with Fe-MPE. This indicates that regions adjacent to drug binding may have altered minor groove width and/or exist in a partially melted state.
Exploring skewed parton distributions with two-body models on the light front. II. Covariant Bethe-Salpeter approach

We explore skewed parton distributions for two-body, light-front wave functions. In order to access all kinematical r\'egimes, we adopt a covariant Bethe-Salpeter approach, which makes use of the underlying equation of motion (here the Weinberg equation) and its Green's function. Such an approach allows for the consistent treatment of the non-wave-function vertex (but rules out the case of phenomenological wave functions derived from ad hoc potentials). Our investigation centers around checking internal consistency by demonstrating time-reversal invariance and continuity between valence and nonvalence r\'egimes. We derive our expressions by assuming the effective $\mathrm{qq}$ potential is independent of the mass squared, and verify the sum rule in a nonrelativistic approximation in which the potential is energy independent. We consider bare-coupling as well as interacting skewed parton distributions and develop approximations for the Green's function which preserve the general properties of these distributions. Lastly, we apply our approach to timelike form factors and find similar expressions for the related generalized distribution amplitudes.
Article use in Spanish-speaking children with specific language impairment.

The current study analysed article use in Spanish-speaking children with specific language impairment who are learning English as a second language. The SURFACE HYPOTHESIS account of specific language impairment was evaluated in relation to the use of articles in these children. Language samples were obtained from 15 Spanish-speaking children with language impairment and 15 with normal language, ages 5;0 to 7;1, matched by age, gender, and school. The percentage of article errors was tested between groups with a nonparametric analysis and an analysis of covariance with mean length of terminable unit as the covariate. Results revealed significant differences between groups on percent of article errors with and without MLTU as the covariate. Nonparametric statistics on percent of article error types indicated that most errors consisted of omissions and gender agreement substitutions. As predicted by the Surface Hypothesis, article errors were likely to occur in unstressed definite articles, suggesting that perceptual and prosodic processes have some impact on children's production of articles.
An alternative approach to computing economic run quantity

Our primary objective is to consider an alternative approach to computing an economic run quantity (ERQ) based on profit maximization. We first develop a general profit function for a firm that includes both production and inventory costs. We then use classical optimization techniques to establish an annual production level that will maximize profit, and use this value to determine an economic run quantity. In comparison to a standard textbook example, our approach leads to a substantial increase in profit. It is also robust over a range of values for production variables. This procedure is a break from the traditional cost minimization approach and may present a more logical methodology for the teaching of inventory management techniques.
Evaluation and management of obesity-related nonalcoholic fatty liver disease

The clinicopathologic spectrum of nonalcoholic fatty liver disease (NAFLD) ranges from simple steatosis to nonalcoholic steatohepatitis (NASH). Simple steatosis has a relatively benign clinical course, but NASH can progress to cirrhosis and hepatocellular carcinoma. NAFLD occurs in the absence of significant alcohol use and is considered to be the hepatic manifestation of metabolic syndrome. NAFLD affects approximately 30% of the US population and the incidence seems to be rising as the obesity epidemic continues. At present, the most accurate modality for the diagnosis of NASH is liver biopsy; however, many patients do not have a liver biopsy, and in the absence of more-accurate imaging technologies and serum markers, the diagnosis is frequently one of exclusion. As yet there is no convincingly effective treatment for NAFLD--a multimodal treatment plan that targets obesity, insulin resistance, hyperlipidemia and hypertension might be the best option for these patients.
What Makes the Airways Contract Abnormally? Is It Inflammation?

What airway smooth muscle definitely does in asthma is contract. Because it encircles the airway, smooth muscle contraction narrows the airway lumen, thereby obstructing airflow, promoting airflow limitation and pulmonary hyperinflation, and thus producing dyspnea in a typical “asthma attack.” However, little is known about airway smooth muscle function in individuals with asthma or how inflammation actually alters airway smooth muscle function. Therefore, we should consider the following as “partially known or conflicting data.”
High expression of class III β-tubulin predicts good response to neoadjuvant taxane and doxorubicin/cyclophosphamide-based chemotherapy in estrogen receptor-negative breast cancer.

Abstract Background Expression of class ΙΙΙ β−tubulin (βΙΙΙ-tubulin) correlates with tumor progression and resistance to taxane-based therapies for several human malignancies including breast cancer. However its predictive value in a neoadjuvant setting in breast cancer remains unexplored. The objective of this explorative study was to determine whether βΙΙΙ-tubulin expression in breast cancer correlated with pathologic characteristics and whether its expression was predictive of response to neoadjuvant chemotherapy. Patients and Methods We determined βΙΙΙ-tubulin expression in 85 breast cancers, including 41 localized breast cancers treated with primary surgery and 44 treated with neoadjuvant chemotherapy before surgery. βΙΙΙ-tubulin expression was evaluated by immunohistochemical methods and was correlated with pathologic characteristics and response to neoadjuvant chemotherapy using residual cancer burden (RCB) score. Results High βΙΙΙ-tubulin expression was significantly associated with poorly differentiated high-grade breast cancers ( P = .003) but not with tumor size, estrogen receptor (ER) status, or human epidermal growth factor receptor 2 (HER2)/ neu overexpression. In ER – tumors treated with neoadjuvant chemotherapy, high βΙΙΙ-tubulin expression was associated with a significantly greater likelihood of achieving a good pathologic response to chemotherapy as reflected by lower RCB scores ( P = .021). Conclusion This study reveals differential βΙΙΙ-tubulin expression in breast cancers of different histologic grades, hormone receptors, and HER2/ neu status. It also suggests a potential role for βΙΙΙ-tubulin as a predictive biomarker for response in neoadjuvant chemotherapy for ER – breast cancer, which has not been previously reported. These data provide a strong rationale for considering βΙΙΙ-tubulin status and further validation of this marker in a large study.
Esophageal Stent Placement for the Treatment of Acute Intrathoracic Anastomotic Leak After Esophagectomy

Background Anastomotic leak after intrathoracic esophagogastrostomy remains a dreaded complication of esophagectomy. Traditional therapy has most often consisted of reoperative repair or observation and drainage, each prolonging hospitalization and the initiation of oral nutrition. This investigation summarizes our experiences treating these patients using an occlusive, removable esophageal stent. Methods Over a 4-year period, patients found to have an acute, significant intrathoracic anastomotic leak after esophagectomy for benign or malignant disease undergoing surgery at or transferred to a single institution were offered endoluminal esophageal stent placement as initial therapy. Stents were placed endoscopically utilizing general anesthesia and fluoroscopy. Leak occlusion was confirmed by esophagram. Patients were followed until their stent was removed and their anastomotic leak had resolved. Results Seventeen patients had an esophageal stent placed for an anastomotic leak during the study period. Leak occlusion occurred in all 17 patients. One patient was found to also have a perforation of the gastric conduit and underwent operative repair. Fourteen patients (82%) were able to initiate oral nutrition within 72 hours of stent placement. Stent migration occurred in 3 patients (18%), requiring repositioning in 2 and replacement in 1. All stents were removed at a mean of 17 ± 9 days after placement. Conclusions Endoluminal esophageal stent placement is a safe and effective method for the treatment of an intrathoracic anastomotic leak after esophagectomy. This treatment resulted in rapid leak occlusion, provided the opportunity for earlier oral nutrition, and avoided the potential morbidity of reoperative repair or esophageal diversion.
The observation of the first vibrational overtone of dihydrogen in the luminescence of zeolites at low temperatures.

Dehydrated zeolites NaA, NaY, and barium-exchanged NaY luminesce when irradiated with the 1064 nm laser light of an FT-Raman instrument. When hydrogen is adsorbed in the zeolite, the luminescence is altered in several ways. Most remarkable is the appearance of "absorptions" in the positions of the first vibrational overtones of H 2 and HD. Although these features are in the expected positions with reasonable band profiles for overtone absorptions, the large extinction of the luminescent intensity requires a more efficient mechanism than simple reabsorption of emitted photons. In addition to the appearance of holes in the luminescence spectrum, other luminescent features are substantially quenched by the presence of hydrogen or, in one case, augmented.
A spectrophotometric method for the simultaneous measurement of l-glutamine and l-asparagine in biological materials

Abstract A rapid and specific spectrophotometric method for measuring the concentration of l -asparagine and l -glutamine in biological materials is presented. Ammonia, released by the enzymic hydrolysis of l -asparagine and l -glutamine, is measured with l -glutamic dehydrogenase. l -Asparaginase from Escherichia coli is used to deaminate first l -asparagine and then l -glutamine. The applicability of the method to biological materials has been demonstrated using extracts of the livers and brains of mice treated with the convulsant amino acid analog, l -methionine- dl -sulfoximine. In animals given this agent subacutely, the concentration of l -glutamine in brain and liver fell significantly, whereas l -asparagine was unaffected. Since even fresh plasma may be used, the assay promises to be a value in measuring the depletion of l -asparagine and l -glutamine in the plasma of patients receiving the oncolytic enzyme, l -asparaginase.
The effects of hormones on sex differences in infection: from genes to behavior.

Abstract Males of many species are more susceptible than females to infections caused by parasites, fungi, bacteria, and viruses. One proximate cause of sex differences in infection is differences in endocrine–immune interactions. Specifically, males may be more susceptible to infection than females because sex steroids, specifically androgens in males and estrogens in females, modulate several aspects of host immunity. It is, however, becoming increasingly more apparent that in addition to affecting host immunity, sex steroid hormones alter genes and behaviors that influence susceptibility and resistance to infection. Thus, males may be more susceptible to infection than females not only because androgens reduce immunocompetence, but because sex steroid hormones affect disease resistance genes and behaviors that make males more susceptible to infection. Consideration of the cumulative effects of sex steroid hormones on susceptibility to infection may serve to clarify current discrepancies in the literature and offer alternative hypotheses to the view that sex steroid hormones only alter susceptibility to infection via changes in host immune function.
NFPA 30: An update and a look into the future

In May 1996, the Flammable and Combustible Liquids Code Committee of the National Fire Protection Association (NFPA) proposed for adoption by the Association a new edition of NFPA 30, Flammable and Combustible Liquids Code. This new edition was the culmination of two and one-half years' work by the Committee and included one of the most significant changes to that document in some twenty years: the incorporation of mandatory fire protection criteria for warehouses and other inside areas that store flammable and combustible liquids in containers and portable tanks.
Remote Control of Gene Expression

The elucidation of a growing number of species' genomes heralds an unprecedented opportunity to ascertain functional attributes of non-coding sequences. In particular, cis regulatory modules (CRMs) controlling gene expression constitute a rich treasure trove of data to be defined and experimentally validated. Such information will provide insight into cell lineage determination and differentiation and the genetic basis of heritable diseases as well as the development of novel tools for restricting the inactivation of genes to specific cell types or conditions. Historically, the study of CRMs and their individual transcription factor binding sites has been limited to proximal regions around gene loci. Two important by-products of the genomics revolution, artificial chromosome vectors and comparative genomics, have fueled efforts to define an increasing number of CRMs acting remotely to control gene expression. Such regulation from a distance has challenged our perspectives of gene expression control and perhaps the very definition of a gene. This review summarizes current approaches to characterize remote control of gene expression in transgenic mice and inherent limitations for accurately interpreting the essential nature of CRM activity.
Optical radiation from shock-compressed materials and interfaces

Recent observations of shock-induced radiation from oxides, silicates and metals of geophysical interest constrain the shock-compressed temperature of these materials. In these experiments, a projectile impacts a target consisting of a metal driver plate, a metal film or foil layer, and a transparent window. We investigate the relationship between the temperature inferred from the observed radiation, and the temperatures of different high-pressures states (e.g. shocked state) of the shock-compressed film (or foil) and window. Deviations of the temperature in each target component away from that of their respective shock-compressed states occur because of (1) shock-impedance mismatch between target components, (2) thermal mismatch between target components, (3) surface roughness at target interfaces, and (4) conduction within and between target components. In particular, conduction may affect the temperature of the film/foil material at the film/foil-window interface, a major thermal radiation source in the target, on the time scale of the experiments. To be observed, radiation from sources at the film/foil-window interface or in the shocked window material must propagate through (1) the shocked window material, (2) the shock front, (3) the unshocked window material, and (4) the unshocked window free surface. Consequently, the observed intensity of target radiation sources is affected by the optical properties of each region. In particular, the source radiation intensity may be greatly reduced due to absorption in the shocked and/or unshocked window material, and/or only partial transmission through the film/foil-window interface, shock front and/or unshocked window free surface. To illustrate various aspects of the model, we apply it to radiation data from targets composed of an Fe driver plate, and Fe film or foil layer, and either an Al_2O_3 or LiF window layer.
Stenols and stanols in the oxic and anoxic waters of the Black Sea

Abstract Water samples collected from a slope station and two deep stations in the western basin of the Black Sea were analyzed for stenols and stanols by glass capillary gas chromatography. These results were used in conjuction with hydrographic, particulate organic carbon, and chlorophyll a data to better understand sterol sources and their transport and transformation mechanisms in anoxic basins. The total free sterol concentrations found in the surface waters were 450–500 ng/l dropping rapidly to values well below 100 ng/l at depths below the O 2 H 2 S interface. In the upper 200 m of the water column a strong association of sterols with particulate matter is suggested. Structural elucidation by a gas chromatograph-mass spectrometer-computer system revealed the presence of at least sixteen different stenols and stanols in the surface waters of the Black Sea. Cholesterol, 24-methylenecholesterol and 24-methylcholesta-5,22-dien-3β-ol were the major sterols in the surface waters. Cholesterol and 24-ethylcholesterol both exhibited a subsurface maximum at the O 2 H 2 S interface. In the anoxic deep waters (200–2000 m) only cholesterol and 24-ethylcholesterol were found. Two stenols were found that have not been reported in seawater: a C26 stenol with a saturated C7H15 side chain (presumably 24-norcholesterol) and 24-ketocholesterol. At least six 5α-stanols could be identified in the surface samples, each of them comprising about 10–20% of the concentration of the corresponding Δ5-stenol. From these comparatively high surface values the stanol concentrations drop rapidly to values near zero at the O 2 H 2 S interface. Except for very low concentrations of 5α-cholestanol ( From this data it appears that no detectable stenol → stanol conversion is occurring at the O 2 H 2 S interface or in the deep anoxic waters of the Black Sea.
Structural elucidation of two major metabolites of crisnatol in the rat by NMR and mass spectrometry

NMR and mass spectral data are presented in support of the structures of two metabolites of crisnatol, 2-[(6-chrysenylmethyl)amino]-2-methylpropane-1,3-diol, a novel DNA intercalator currently undergoing Phase II clinical trials as an anticancer agent. Elucidation of the structures of the major rat urinary metabolite as trans-1,2-dihydro-1,2-dihydroxycrisnatol, and the major rat fecal metabolite as 1-hydroxycrisnatol, using 2D NMR techniques are described.
The Mexican Health Paradox Expanding the Explanatory Power of the Acculturation Construct

The Mexican health paradox refers to initially favorable health and mental health outcomes among recent Mexican immigrants to the United States. The subsequent rapid decline in Mexican health outco...
Synthetic gene carriers: the future looks bright

Abstract Structure and Design of Synthetic Gene Carriers San Francisco, CA, USA, 24–26 February 1999
Mental Models and Creative Problem-Solving: The Relationship of Objective and Subjective Model Attributes

Knowledge, or expertise, has been held to contribute to creative problem-solving. In this effort, the relationship of one form of knowledge, mental models, to creative problem-solving was assessed. Undergraduates were asked to solve either a marketing or an education problem calling for creative thought. Prior to generating solutions to these problems, the mental models used by undergraduates to understand problems in these domains were assessed in terms of their objective and subjective features. It was found that both objective and subjective features of peoples mental models were related to the quality, originality, and elegance of problem solutions. The implications of these findings for understanding the role of mental models in creative problem-solving are discussed.
Pneumococci Stimulate the Production of Inducible Nitric Oxide Synthase and Nitric Oxide by Murine Macrophages † 887

The role of nitric oxide (NO) in the pathophysiology of gram-positive sepsis is uncertain. In inflammatory conditions, high-output NO production is catalyzed by the enzyme inducible nitric oxide synthase (iNOS). The ability of 2 strains of pneumococci, pneumococcal cell wall preparations, and purified pneumococcal capsule (Pnu-Imune 23) to trigger the production of iNOS protein and NO in RAW 264.7 murine macrophages was tested. Live pneumococci, oxacillin-killed pneumococci, and pneumococcal cell wall preparations stimulated the production of iNOS and NO by RAW 264.7 cells in the presence, but not the absence, of low concentrations of recombinant murine interferon-g. In contrast, purified pneumococcal capsule induced little or no iNOS or NO production by these cells. Thus, pneumococci stimulate high-output NO production by murine macrophages. The potential role of NO in the pathogenesis of pneumococcal sepsis deserves further study. Nitric oxide (NO) and tumor necrosis factor (TNF) have been found to play important roles in the pathogenesis of gramnegative septic shock. During inflammatory states, the enzyme inducible nitric oxide synthase (iNOS) catalyzes the hyperproduction of NO by various mammalian cells [1]. Murine macrophages produce large amounts of NO in response to inflammatory stimuli, but the existence of the high-output NO pathway in isolated human monocytes and macrophages has been controversial (reviewed in [2]). However, biosynthesis of iNOS protein [3, 4] and iNOS mRNA [3, 5] has recently been unequivocally demonstrated in human mononuclear cells in vivo during infection. In addition, nitrite accumulation has been detected in human monocyte-derived macrophages after a polyribonucleotide stimulus and was enhanced by pretreatment with interferon-g (IFN-g) [6]. In both humans and experimental animals, symptomatology of hypotension, vasoplegia to exogenous catecholamines, and end-organ dysfunction correlate with increased levels of NO during sepsis [7]. Most of the previous studies of NO production by macrophages have used gram-negative organisms or their major virulence factor, lipopolysaccharide (LPS), as the stimulus.
Itinerant electron magnetism in the quantum Hall regime

Abstract The two-dimensional interacting electron gas at Landau level filling factor f =1 at temperature T = 0 is a strong ferromagnet; all spins are completely aligned by arbitrarily weak Zeeman coupling. We report on a theoretical study of its thermodynamic properties, particularly the temperature dependence of the spin magnetization. Our study is based on an approximation in which the self-energy includes contributions obtained by summing up particle-hole ladders which take into account the presence of low-energy collective spin-wave excitations. The emission and absorption of spin waves is accompanied by electronic spin flips. In our approximation the spin-wave bands narrow with increasing temperature leading eventually to an abrupt decrease of the spin magnetization. We compare our results with recent magnetization data from NMR measurements by Barrett et al.
A chelating β-diketonate/phenoxide ligand and its coordination behavior toward titanium and scandium

Dibenzoylmethane derivatives with one (L1H2) or both (L2H3, L3H3) benzenes linked at their ortho positions to 4,6-di-tert-butylphenol moieties by two-carbon linkers have been synthesized. The mono-β-diketone-monophenol ligand L1H2 is metalated by titanium alkoxides to form the homoleptic complex (L1)2Ti and heteroleptic complexes (L1)Ti([OCH2CH2]2NR) (R = H, CH3), and reacts with Cp3Sc to form CpSc(L1). These are the first examples of complexes of a β-diketonate ligand which is further chelating to a single metal center. Crystallographic analysis of (L1)2Ti indicates that the 10-membered ring allows chelation of the phenoxide with little strain, and both fac and mer geometries are accessible in solution. Protonolysis of the second cyclopentadienyl ring of Cp3Sc appears to take place by an indirect, Cp3Sc-catalyzed pathway.
Nematodes as an indicator of plant-soil interactions associated with desertification

Abstract Conversion of perennial grasslands to shrublands is a desertification process that is important globally. Changes in aboveground ecosystem properties with this conversion have been well-documented, but little is known about how belowground communities are affected, yet these communities may be important drivers of desertification as well as constraints on the reversal of this state change. We examined nematode community structure and feeding as a proxy for soil biotic change across a desertification gradient in southern NM, USA. We had two objectives: (1) to compare nematode trophic structure and species diversity within vegetation states representing different stages of desertification, and (2) to compare nematode community structure between bare and vegetated patches that may be connected via a matrix of endophytic fungi and soil biotic crusts. The gradient included a perennial grassland dominated by Bouteloua eriopoda, the historic dominant in the Chihuahuan Desert, a duneland dominated by the shrub, Prosopis glandulosa, and the ecotone between them. We also sampled a relatively undisturbed, ungrazed B. eriopoda grassland at a nearby site to serve as an end member of our gradient. Nematode communities were sampled using soil cores to depth of 50 cm at each location in 2009 and 2010. Results showed that grasslands and mesquite dunelands had different trophic groupings and herbivorous nematode communities with lower species diversity and evenness compared with the ecotone. Nematode trophic structure and herbivore communities were significantly different in all vegetation states with the highest observed diversity in the undisturbed, ungrazed B. eriopoda grassland in 2010. Vegetated and bare ground patches within the two grassland sites had similar herbivore communities, especially species from the family Tylenchinae. However, the mesquite duneland showed the lowest sampled diversity of all sites, but had significantly larger nematode abundances in vegetated dunes than interdune areas that are void of vegetation and soil biotic crusts where bacteriovores dominated. Decreased nematode trophic structure and species diversity in the Jornada black grama grassland samples compared with the undisturbed grassland illustrate the effect of desertification on the soil biotic community. Our results show that nematodes can be used to identify changes in belowground community structure based on trophic interactions. Large-scale disturbances like desertification can have consequences on the diversity and soil biotic functioning at finer spatial scales.
Deconvoluting the intestine: molecular evidence for a major role of the mesenchyme in the modulation of signaling cross talk

Reciprocal cross talk between the endodermally derived epithelium and the underlying mesenchyme is required for regional patterning and proper differentiation of the developing mammalian intestine....
Rapid ultra-wideband signal acquisition

Low transmission power and a highly spread bandwidth makes the acquisition of ultra-wideband (UWB) signals a difficult problem. In a packet-based network employing UWB modulation in the physical layer, long preambles need to be prepended to each packet because the low signal power requires the receiver to process the signal for long periods of time in order to estimate the timing of the signal. The long spreading or hopping sequences used in UWB systems result in a large search space for the acquisition system at the receiver. This work presents a signal acquisition system for UWB which employs a hybrid signaling format involving direct sequence (DS) spreading and time hopping (TH), significantly reducing the search space in the UWB acquisition system. The acquisition system employs equal gain combining (EGC) which enables the utilization of the energy of the dense multipath, typical of a UWB channel. The performance of the acquisition system has been analytically evaluated and is corroborated through simulation.
Inducing mineral precipitation in groundwater by addition of phosphate

Induced precipitation of phosphate minerals to scavenge trace elements from groundwater is a potential remediation approach for contaminated aquifers. The success of engineered precipitation schemes depends on the particular phases generated, their rates of formation, and their long term stability. The purpose of this study was to examine the precipitation of calcium phosphate minerals under conditions representative of a natural groundwater. Because microorganisms are present in groundwater, and because some proposed schemes for phosphate mineral precipitation rely on stimulation of native microbial populations, we also tested the effect of bacterial cells (initial densities of 105 and 107 mL-1) added to the precipitation medium. In addition, we tested the effect of a trace mixture of propionic, isovaleric, formic and butyric acids (total concentration 0.035 mM). The general progression of mineral precipitation was similar under all of the study conditions, with initial formation of amorphous calcium phosphate, and transformation to poorly crystalline hydroxylapatite (HAP) within one week. The presence of the bacterial cells appeared to delay precipitation, although by the end of the experiments the overall extent of precipitation was similar for all treatments. The stoichiometry of the final precipitates as well as Rietveld structure refinement using x-ray diffraction data indicated that the presence of organic acids and bacterial cells resulted in an increasing a and decreasing c lattice parameter, with the higher concentration of cells resulting in the greatest distortion. Uptake of Sr into the solids was decreased in the treatments with cells and organic acids, compared to the control. Our results suggest that the minerals formed initially during an engineered precipitation application for trace element sequestration may not be the ones that control long-term immobilization of the contaminants. In addition, the presence of bacterial cells appears to be associated with delayed HAP precipitation, changes in the lattice parameters, and reduced incorporation of trace elements as compared to cell-free systems. Schemes to remediate groundwater contaminated with trace metals that are based on enhanced phosphate mineral precipitation may need to account for these phenomena, particularly if the remediation approach relies on enhancement of in situ microbial populations.
The Nuclear Pore Complex and Nuclear Transport

Internal membrane bound structures sequester all genetic material in eukaryotic cells. The most prominent of these structures is the nucleus, which is bounded by a double membrane termed the nuclear envelope (NE). Though this NE separates the nucleoplasm and genetic material within the nucleus from the surrounding cytoplasm, it is studded throughout with portals called nuclear pore complexes (NPCs). The NPC is a highly selective, bidirectional transporter for a tremendous range of protein and ribonucleoprotein cargoes. All the while the NPC must prevent the passage of nonspecific macromolecules, yet allow the free diffusion of water, sugars, and ions. These many types of nuclear transport are regulated at multiple stages, and the NPC carries binding sites for many of the proteins that modulate and modify the cargoes as they pass across the NE. Assembly, maintenance, and repair of the NPC must somehow occur while maintaining the integrity of the NE. Finally, the NPC appears to be an anchor for localization of many nuclear processes, including gene activation and cell cycle regulation. All these requirements demonstrate the complex design of the NPC and the integral role it plays in key cellular processes.
Effect of skeletonization of the internal thoracic artery on vessel wall integrity.

Abstract Background . This study was conceived to evaluate the effect of internal thoracic artery (ITA) skeletonization on vessel wall integrity. Methods . Forty consecutive patients undergoing coronary artery bypass were randomized to receive a skeletonized (n = 22) or a pedicled (n = 18) ITA graft. ITA harvesting was performed by 2 experienced surgeons using the same instrumentation and technique. Specimens were examined by light and electron microscope in order to assess vascular wall integrity. A specific immunohistochemical staining and a computerized method were used to quantify the degree of endothelial integrity after surgical preparation. Results . Morphologic analysis revealed 2 cases of limited subadventitial hemorrhage (one for each group) and no case of major arterial damage. Immunohistochemical staining demonstrated an extremely high degree of maintenance of the endothelial integrity in both groups (97.2% ± 1.9% in the skeletonized and 96.8% ± 2.1% in the pedicled one; p = 0.53). Conclusions . Skeletonization does not affect ITA wall integrity in humans submitted to coronary artery bypass procedures.
Anglo-American Wage Differences in the 1820's

In 1829 Zachariah Allen, a lifelong resident of Providence, Rhode Island, published his book, The Science of Mechanics. Neither the title nor a casual glance at the contents of the book suggests that it contains material of major interest to economists or economic historians. Allen's book was intended as a manual for American mechanics and manufacturers. It summarized that portion of the industrial arts of its day which the author considered most useful and relevant for the edification of his American readers. The book contains elementary tables of conversion, arithmetic and geometric rules and formulas, a good deal of simple physics, and extensive descriptions of the workings of machinery—especially water wheels, steam engines, and millwork generally. In particular, Allen attempted to summarize much of what he had learned during a recent tour of the major manufacturing districts of England and France, so as to bring Americans up to date on the “latest improvements in mechanical invention in those countries.’ Unobtrusively placed in the back of this book, however, is a chapter, “Comparative View of the Relative Advantages Possessed by England, France and the United States of America as Manufacturing Nations,’ which records his more strictly economic impressions of his tour, taken in 1825. His observations in this short chapter, often trenchant and occasionally pungent, invite comparison with some of the better known European travelers to the United States. Anyone who can write, as Allen does (p. 355), that “An industrious New-England mechanic commonly appears to take pleasure in his business; but the French mechanic is rather inclined to make a business of his pleasures,’ is obviously entitled to a sympathetic hearing.
CNTRICS Final Task Selection: Social Cognitive and Affective Neuroscience–Based Measures

This article describes the results and recommendations of the third Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia meeting related to measuring treatment effects on social and affective processing. At the first meeting, it was recommended that measurement development focuses on the construct of emotion identification and responding. Five Tasks were nominated as candidate measures for this construct via the premeeting web-based survey. Two of the 5 tasks were recommended for immediate translation, the Penn Emotion Recognition Task and the Facial Affect Recognition and the Effects of Situational Context, which provides a measure of emotion identification and responding as well as a related, higher level construct, context-based modulation of emotional responding. This article summarizes the criteria-based, consensus building analysis of each nominated task that led to these 2 paradigms being recommended as priority tasks for development as measures of treatment effects on negative symptoms in schizophrenia.
Nonbacterial Infections of the Genitourinary Tract

The presence of fungal infections in genitourinary organs has become a common occurrence with the continuing increase in immunocompromised populations, and improved critical care of the elderly. A variety of fungi, either opportunistic or pathogens endemic to a specific region, cause human disease. Thus, a working knowledge of the common fungal infections, their clinical manifestations, and an awareness of at-risk populations is essential to early diagnosis and aggressive treatment.
Random testing of formal software models and induced coverage

This paper presents a methodology for random testing of software models. Random testing tools can be used very effectively early in the modeling process, e.g., while writing formal requirements specification for a given system. In this phase users cannot know whether a correct operational model is being built or whether the properties that the model must satisfy are correctly identified and stated. So it is very useful to have tools to quickly identify errors in the operational model or in the properties, and make appropriate corrections. Using Lurch, our random testing tool for finite-state models, we evaluated the effectiveness of random model testing by detecting manually seeded errors in an SCR specification of a real-world personnel access control system. Having detected over 80% of seeded errors quickly, our results appear to be very encouraging. We further defined and measured test coverage metrics with the goal of understanding why some of the mutants were not detected. Coverage measures allowed us to understand the pitfalls of random testing of formal models, thus providing opportunities for future improvement.
A comprehensive assessment of sequence-based and template-based methods for protein contact prediction

Motivation: Pair-wise residue-residue contacts in proteins can be predicted from both threading templates and sequence-based machine learning. However, most structure modeling approaches only use the template-based contact predictions in guiding the simulations; this is partly because the sequence-based contact predictions are usually considered to be less accurate than that by threading. With the rapid progress in sequence databases and machine-learning techniques, it is necessary to have a detailed and comprehensive assessment of the contact-prediction methods in different template conditions. Results: We develop two methods for protein-contact predictions: SVM-SEQ is a sequence-based machine learning approach which trains a variety of sequence-derived features on contact maps; SVM-LOMETS collects consensus contact predictions from multiple threading templates. We test both methods on the same set of 554 proteins which are categorized into ‘Easy’, ‘Medium’, ‘Hard’ and ‘Very Hard’ targets based on the evolutionary and structural distance between templates and targets. For the Easy and Medium targets, SVM-LOMETS obviously outperforms SVM-SEQ; but for the Hard and Very Hard targets, the accuracy of the SVM-SEQ predictions is higher than that of SVM-LOMETS by 12–25%. If we combine the SVM-SEQ and SVM-LOMETS predictions together, the total number of correctly predicted contacts in the Hard proteins will increase by more than 60% (or 70% for the long-range contact with a sequence separation ≥24), compared with SVM-LOMETS alone. The advantage of SVM-SEQ is also shown in the CASP7 free modeling targets where the SVM-SEQ is around four times more accurate than SVM-LOMETS in the long-range contact prediction. These data demonstrate that the state-of-the-art sequence-based contact prediction has reached a level which may be helpful in assisting tertiary structure modeling for the targets which do not have close structure templates. The maximum yield should be obtained by the combination of both sequence-and template-based predictions. Contact: yzhang@ku.edu Supplementary information: Supplementary data are available at Bioinformatics online.
Block permutations in Boolean Space to minimize TCAM for packet classification

Packet classification is one of the major challenges in designing high-speed routers and firewalls as it involves sophisticated multi-dimensional searching. Ternary Content Addressable Memory (TCAM) has been widely used to implement packet classification thanks to its parallel search capability and constant processing speed. However, TCAM-based packet classification has the well-known range expansion problem, resulting in a huge waste of TCAM entries. In this paper, we propose a novel technique called Block Permutation (BP) to compress the packet classification rules stored in TCAMs. The compression is achieved by performing block-based permutations on the rules represented in Boolean Space. We develop an efficient heuristic approach to find the permutations for compression and design its hardware implementation. Experiments on ClassBench classifiers and ISP classifiers show that the proposed BP technique can reduce TCAM entries by 53.99% on average.
Ecto 5′-Nucleotidase and Nonspecific Alkaline Phosphatase TWO AMP-HYDROLYZING ECTOENZYMES WITH DISTINCT ROLES IN HUMAN AIRWAYS

In human airways, extracellular adenosine regulates epithelial functions supporting mucociliary clearance, an important airway defense mechanism against bacterial infection. Thus, defining the mechanisms of adenosine generation is critical for elucidating the role of this nucleoside in airway homeostasis. In this study, we identified the source of adenosine on the mucosal surface of human airway epithelia. Polarized primary cultures of human nasal or bronchial epithelial cells were assayed for transepithelial transport, cytosolic and cell surface adenosine production. Ussing chamber experiments indicated that serosal 1 microM [(3)H]adenosine was not transported to the mucosal compartment. Messenger RNA for the cytosolic AMP-specific 5'-nucleotidase (CN-I) was not detected in human bronchial epithelial cells, suggesting that mucosal adenosine did not originate from intracellular pools. In contrast, extracellular 0.1 mm ATP was rapidly dephosphorylated into adenosine on the mucosal epithelial surface. We identified two ectonucleotidases that mediated the conversion of AMP to adenosine: ecto 5'-nucleotidase (ecto 5'-NT, CD73) and alkaline phosphatase (AP). Both mucosal and serosal epithelial surfaces displayed ecto 5'-NT activity (K(m) = 14 microM, V(max) = 0.5 nmol x min(-1) x cm(-2)), whereas AP activity was restricted to the mucosal surface (K(m,)(high) = 36 microM, V(max) = 1.2 nmol x min(-1) x cm(-2); K(m,)(low) = 717 microM, V(max) = 2.8 nmol x min(-1) x cm(-2)). In bronchial cultures and tissues, ecto 5'-NT accounted for >80% of total activity toward 0.01 mm AMP, compared with <15% for 5 mm AMP. The proximal airway AP isoform was identified as nonspecific AP (NS AP) by levamisole sensitivity and mRNA expression. The two ectoenzymes presented opposite airway distributions, ecto 5'-NT and NS AP mRNA dominating in higher and lower airways, respectively. Collectively, these experiments support a major role for extracellular nucleotide catalysis and for ecto 5'-NT and NS AP in the regulation of adenosine concentrations on airway surfaces.
A common Lyapunov function for stable LTI systems with commuting A-matrices

The paper demonstrates that a common quadratic Lyapunov function exists for all linear systems of the form x/spl dot/=A/sub i/x, i=1,2,/spl middot//spl middot//spl middot/,N, where the matrices A/sub i/ are asymptotically stable and commute pairwise. This in turn assures the exponential stability of a switching system x/spl dot/(t)=A(t)x(t) where A(t) switches between the above constant matrices A/sub i/. >
EXPERIMENTAL MESOCOSM STUDIES OF SALINITY EFFECTS ON THE BENTHIC ALGAL COMMUNITY OF A SALINE LAKE

As closed-basin systems, saline lakes are prone to fluctuate in level and salinity with climate change and hydrologic alterations. Loss of many Great Basin lakes has resulted from the diversion of tributary streams for agricultural or municipal uses. At Mono Lake, an alkaline salt lake in eastern California, salinities have risen from 50 to 100 g·L21 in just 50 years. Experimental mesocosms were established to simulate some of the potential ecological effects that could have accompanied this change. The influence of salinity on diatom diversity, taxonomic structure, and primary production was tested using mesocosms deployed at Mono Lake. Mesocosm tanks were 500 L in volume, 1 m square, and 0.5 m deep, with open tops covered by 1 mm mesh net. Five treatments (50, 75, 100, 125, and 150 g·L21) with four replicates per treatment were used over a 2-month period. The diatom-dominated benthic algae were reduced both in standing crop (from 6 to ,0.1 g·m 22) and diversity (from 30 to 12 taxa) with increased salinity, with most loss occurring in salinities $75 g·L 21 . Photosynthetic oxygen production also was significantly lower at salinities $75 g·L 21 . Diatom indicator taxa for these shifts included Denticula sp., Nitzschia frustulum, N. monoensis, N. communis, and Stephanodiscus oregonicus increasing in relative abundance in higher salinity treatments, accompanied by decreases in Achnanthes minutissima, Cymbella minuta, N. dissipata, and Rhoicosphenia abbreviata. Exhibiting dominance at moderate salinity levels (75 to 125 g·L21) were Nitzschia frustulum, N. communis, N. palea, and Navicula crucialis. These latter species may be limited by both physiological stress at high salinity and grazing and competition at low salinity. The filamentous chlorophyte, Ctenocladus circinnatus, and cyanobacteria (Oscillatoria spp.) occurred only in salinity treatments from 50 to 100 g·L21 . Diversion of tributary stream flow and resulting salinity increases in this lake threaten sustained benthic primary production and algal species diversity relative to conditions prior to stream diversion. The 1994 decision of the California State Water Resources Control Board to return stream flows to Mono Lake will raise the lake level and reduce salinity to around 75 g·L21 and is expected to increase the diversity and productivity of the benthic algae of this ecosystem.