cssi/SciSciGPT-SciSciNet huggingface dataset:
Ramifications of kinetic partitioning on usher‐mediated pilus biogenesis

The biogenesis of diverse adhesive structures in a variety of Gram‐negative bacterial species is dependent on the chaperone/usher pathway. Very little is known about how the usher protein translocates protein subunits across the outer membrane or how assembly of these adhesive structures occurs. We have discovered several mechanisms by which the usher protein acts to regulate the ordered assembly of type 1 pili, specifically through critical interactions of the chaperone–adhesin complex with the usher. A study of association and dissociation events of chaperone–subunit complexes with the usher in real time using surface plasmon resonance revealed that the chaperone–adhesin complex has the tightest and fastest association with the usher. This suggests that kinetic partitioning of chaperone–adhesin complexes to the usher is a defining factor in tip localization of the adhesin in the pilus. Furthermore, we identified and purified a chaperone–adhesin–usher assembly intermediate that was formed in vivo . Trypsin digestion assays showed that the usher in this complex was in an altered conformation, which was maintained during pilus assembly. The data support a model in which binding of the chaperone–adhesin complex to the usher stabilizes the usher in an assembly‐competent conformation and allows initiation of pilus assembly.
A bimetallic N-heterocyclic carbene complex featuring a short Cr-Cr distance.

The alkylation of a chelating bis(carbene) complex of CrCl2 yields an unusual bimetallic complex featuring a short Cr–Cr distance, novel ligand coordination, and CH3 ligand exchange.
Three-Dimensional Reconstruction Of Tissues And Organs From Sections At The National Center For Supercomputing Applications

A schemata for 3-D reconstructions from images of serial sections of biological tissues is presented. A classification map is constructed from statistical analysis of populations of n-tupled image pixels. 1-tuples are assigned optical properties such as refractive index, optical density, hue, and saturation. Image sections are transformed into classified sections using the map and then stacked. The data set is processed by a program cognizant of the laws of polychromatic white light propagation through space.
c-Abl and Arg are activated in human primary melanomas, promote melanoma cell invasion via distinct pathways, and drive metastatic progression

c-Abl and Arg are activated in human primary melanomas, promote melanoma cell invasion via distinct pathways, and drive metastatic progression
Hippocampal neuronal necrosis in control Fischer 344 rats.

Summary Brain tissue sections from control male and female Fischer 344 (F344) rats from ten National Toxicology Program (NTP) Bioassays were histomorphologically reviewed for non-neoplastic lesions of the hippocampus. Unilateral segmental hippocampal neuronal necrosis, which has not been reported in normal rats, was observed in 9 of 433 (2·1 per cent) males and 1 of 454 (0·2 per cent) females. Significant coexisting lesions were left-sided atrial and/or valvular thrombosis, metastatic mesothelioma, and large lymphocyte leukaemia. These data suggest that this naturally occurring lesion of predominantly aged male rats may result from an impairment of cerebral perfusion secondary to vascular obstruction by thrombotic emboli or leukaemic cells and haemolytic anaemia concomitant with large lymphocyte leukaemia, which commonly occurs in F344 rats.
Effectiveness of the Ppvt-r in tHe Screening of Young Gifted Children

The Stanford-Binet Intelligence Scale, Form L-M, and the Peabody Picture Vocabulary Test-Revised (PPVT-R), Form M, were administered to 100 preschool, kindergarten, and first grade children (ages 3 years, 10 months to 6 years, 11 months). The sample contained a high proportion of children who were perceived by parents as being above average or intellectually gifted. The mean PPVT-R standard score for this referral sample was 111.43 (SD = 13.86) and the mean Stanford-Binet IQ score was 123.72 (SD = 16.79). Analysis of the results indicated a correlation between the instruments of .58, and the mean scores were significantly different on the two measures (p < .0001). Examination of the data revealed that differences were greater for children at the upper IQ ranges (120 +) than at the lower ranges. Based on the results of this study, it appears that the efficacy of the PPVT-R as a screening instrument for the identification of young gifted children is questionable if conventional intelligence measures such as...
Assessment of the effects of neonatal subcutaneous 6-hydroxydopamine on noradrenergic and dopaminergic innervation of the cerebral cortex

Female rats, treated at birth with 6-hydroxydopamine (3 x 100 mg/kg s.c. at 24 h intervals) or vehicle, were subjected at 112 days of age to unilateral electrolytic lesions of the locus coeruleus. Two weeks later regions of the telencephalon, both ipsi- and contralateral to the lesion, were simultaneously assayed for norepinephrine (NE) and dopamine (DA) content, and for tyrosine hydroxylase (TOH) and dopamine-beta-hydroxylase (DBH) activities. In the vehicle-treated rats the lesion resulted in at least an 80% reduction of NE and DBH on the ipsilateral side, relative to the contralateral side. TOH was reduced to a similar extent only in the parietal cortex and hippocampus. In the prefrontal cortex and cingulate gyrus TOH was decreased by only 31% and 64% respectively; the remainder was interpreted to be associated with projections of the mesocortical dopamine system. From this data it was possible to calculate that the ratio of TOH to DA in dopaminergic terminals is about 10-fold greater than the ratio of TOH to NE in noradrenergic terminals. Neonatal 6-hydroxydopamine treatment resulted in practically total elimination of noradrenergic terminals throughout the telencephalon, and the locus coeruleus lesion had no additional effect. The drug treatment produced no significant change in DA content or in the TOH to DA ratio in the prefrontal cortex and cingulate gyrus, indicating complete sparing of the mesocortical DA projections.
Annexin-Mediated Matrix Vesicle Calcification in Vascular Smooth Muscle Cells†

In bone, osteoblasts and chondrocytes synthesize matrix vesicles (MVs) that interact with collagen to initiate calcification. MVs have been identified in human calcified arteries but are poorly characterized. The objective of this study is to determine the role of annexins and fetuin-A in MV formation and activity during calcification in bovine vascular smooth muscle cells (BVSMCs). BVSMCs were treated with control or calcification (high phosphorus) media, and cellular MVs were isolated by collagenase digestion and secreted MVs were isolated from cultured media by ultracentrifugation. The results showed that alkaline phosphatase (ALP) activity was significantly increased in MVs from calcified BVSMCs compared with noncalcified BVSMCs, as was annexin II and VI content and 45Ca uptake. We also determined that MVs from calcifying BVSMCs could mineralize type I collagen but not type II collagen in the absence of cells in a dose- and time-dependent manner. Blockade of annexin calcium channel activity by K201 significantly decreased ALP activity and reduced the ability of the MVs to subsequently calcify on collagen, whether the K201 was added during or after MV formation. Furthermore, cellular MVs had significantly increased ability to calcify on collagen compared with secreted MVs, likely because of their increased ALP activity and annexin II content but low fetuin-A content. In conclusion, our results suggest that mineralization in VSMCs requires both active MVs and an interaction of the MVs with type I collagen, and both steps require annexin activity.
Methods for Studying Symbolic Behavior and Category Formation: Contributions of Stimulus Equivalence Research

Abstract How do humans categorize items and events in their world, and what role does language play in this process? Such questions have been at the center of long-standing debate among philosophers and scientists from many eras, cultures, and disciplines. Fundamental to this debate are difficult questions of what is meant by the concept of a linguistic symbol. For instance, philosophers and scientists alike have articulated a conceptual distinction between the relations involved in rich linguistic symbols (true words) as compared to restricted paired associates (rote-learned associations). Yet it remains difficult to specify behaviorally what actually makes these two types of relations different. In this article, we describe methodology that may offer an operationalized model that allows empirical analysis of paired associate versus symbolic learning. Like any methodology, our approach alone does not pretend to fully resolve age-old questions. However, we intend to illustrate distinct advantages offered within this approach to scholars interested in symbolic functioning and its development.
Nitrogen and phosphorus distribution and utilization by Spartina alterniflora in a Louisiana gulf coast marsh

Nitrogen and phosphorus content ofSpartina alterniflora Loisel and soil nitrogen were measured along a transect perpendicular to a stream in a Louisiana salt marsh in order to provide information on differences between the so-called streamside and inland regions. Total plant nitrogen and phosphorus levels in June and September tended to be greater at streamside than inland sites. Total soil nitrogen on a dry soil weight basis increased with distance inland from a natural stream toward an interdistributary basin in the marsh. Soil extractable ammonium-nitrogen levels measured in June were very low in vegetated streamside and inland areas, but they were much higher in inland areas devoid of plants. Nitrogen and phosphorus utilization byS. alterniflora was also investigated at an inland location in the salt marsh. Labelled ammonium-nitrogen and phosphate-phosphorus were added in May at a rate of 200 kg/ha to the soil of replicated plots. Added nitrogen significantly increased total above-ground plant biomass and plant height by 28 and 25%, respectively, 4 months after application. The ratio of belowground macro-organic matter to total aboveground biomass was decreased from 5.7 to 4.7 by the additional nitrogen. Added phosphorus did not significantly affect plant height and biomass. The use of15N-depleted nitrogen tracers showed that about half of the nitrogen in the aboveground portion ofS. alterniflora from 1 to 4 months after the nitrogen addition was derived from the added ammonium-nitrogen. After 4 months, 28 and 29% of the added labelled nitrogen was recovered in the aboverground and belowground biomass ofS. alterniflora, respectively. Recovery of added nitrogen was overestimated with a non-tracer method based on the difference in total nitrogen uptake between nitrogen-amended plots and untreated plots. Soil organic nitrogen comprised the majority of the nitrogen in the salt marsh. Nitrogen in the standing crop biomass ofS. alterniflora represented only about 2% of the total nitrogen in the plantsoil system of an inland marsh to a 20 cm soil depth.
Electrical resistance of silicon carbide alloyed with nitrogen and articles made from it

Nitrogen alloyed silicon carbide has a lower resistivity and is statistically more uniform as regards this factor than ordinary silicon carbide. In batches of articles made in industrial conditions from nitrogen alloyed silicon carbide the electrical resistance is 40% lower, and has half the spread of the values.
Housing in an Internationalizing Region: Housing Stock Dynamics in Southern California and the Dilemmas of Fair Share

The Los Angeles region is undergoing an unprecedented internationalization of its population. This trend is introducing a number of Third World characteristics into the region, not the least of which are extremes in housing wealth, overcrowding, and reghettoization of its urban cores. The region is also attempting to implement a fair-share housing effort to counteract this reghettoization. Analysis of the housing-stock dynamics in the region reveals inherent dilemmas in this effort. It also suggests the need to reconsider local government land-use and housing regulations.
Colloid aggregation: numerical solution and measurements

Abstract A model has been developed that describes the kinetics of particle aggregation by a numerical solution of the von Smoluchowski equation. While the complete model incorporates surface chemical phenomena, this paper discusses only the physical aggregation process, and focuses on long-term aggregation where aggregates composed of many primary particles (up to 2000) are formed. Model simulations were compared with laboratory experiments that were conducted with hematite spheres aggregating with no applied shear stress. Comparison was achieved by minimizing the sum of squared differences between the model and experimental data using two fitting parameters: the collision efficiency and the fractal dimension of the aggregates. The model was sensitive to the two parameters, which had a small degree of dependence on one another as evidenced by the orientation of the joint confidence regions. Estimates of the fractal dimension varied inversely with collision efficiency and were between 1.25 and 1.5; lower than many estimates by others for diffusion-controlled processes but consistent with cluster–cluster aggregation of aggregates comprised of very dense particles. The collision efficiency was estimated to be 1×10−4 for slow aggregation conditions, and 2×10−4 under rapid aggregation; these values reflect inclusion of hydrodynamic interactions and their significance in a system dominated by differential settling.
Variational Approach to the Prediction of Excess Thermodynamic Properties of Binary Liquid Mixtures. IV

The variational technique which is proposed earlier [J. Chem. Phys. 53, 1931 (1970)] is applied for the prediction of the excess thermodynamic properties of binary liquid mixtures. The results are compared with the experimental and machine‐calculated, Monte Carlo, data. Also comparisons are made with the results of the other theories of mixtures. It is shown that the variational technique is a stronger tool for quantitative predictions of the excess thermodynamic properties of liquid mixtures than the other existing theories of mixtures.
Activation of N-myc2 gene expression by cis-acting elements of oncogenic hepadnaviral genomes: key role of enhancer II.

Abstract Woodchuck hepatitis virus (WHV) is strongly oncogenic in its native host, producing hepatocellular carcinomas in the majority of chronically infected animals. An important step in this oncogenic process is the activation of N-myc transcription in the liver as a result of integration of viral sequencesin cisto the N-myc2 locus. We have examined the viral sequences involved in the up-regulation of N-myc2 using transient transfection assays of permissive HepG2 cells in culture. WHV sequences corresponding to enhancer I of human hepatitis B virus are nearly inactive in N-myc2 activation when tested alone and are not significantly activated by WHV X gene coexpression. By contrast, sequences corresponding to enhancer II strongly activate expression in a position and orientation-independent manner and are only modestly further up-regulated by WHx expression. Qualitatively similar results were observed with sequences of the ground squirrel hepatitis virus (GSHV), which produces hepatomas in woodchucks without insertional activation of N-myc2, but the GSHV EnII element is fourfold less active in N-myc2 up-regulation than its WHV counterpart.
Molecular association between ATR and two components of the nucleosome remodeling and deacetylating complex, HDAC2 and CHD4.

Ataxia telangiectasia mutated (ATM)- and Rad3-related protein (ATR) is a phosphatidylinositol-kinase (PIK)-related kinase that has been implicated in the response of human cells to multiple forms of DNA damage and may play a role in the DNA replication checkpoint. The purification of an ATR complex allowed identification of chromodomain-helicase-DNA-binding protein 4 (CHD4) as an ATR-associated protein by tandem mass spectrometric sequencing. CHD4 (also called Mi-2β) is a component of a histone-deacetylase-2 (HDAC2)-containing complex, the nucleosome remodeling and deacetylating (NRD) complex. Endogenous ATR, CHD4, and HDAC2 are shown to coimmunoprecipitate, and ATR and HDAC2 coelute through two biochemical purification steps. Other members of the NRD complex, HDAC1, MTA1, and MTA2, are also detectable in ATR immunoprecipitates. ATR's association with CHD4 and HDAC2 suggests that there may be a linkage between ATR's role in mediating checkpoints induced by DNA damage and chromatin modulation via remodelin...
Heterologous expression and in vitro folding of the human of Surfactant Protein B precursor. • 1642

Aim: To test the hypothesis that precursor flanking sequences assist in the folding of mature Surfactant Protein B (SP-B).
SU‐FF‐T‐435: Dosimetry Performance Comparison of Proton IMPT Versus Photon IMRT for Ocular Tumors Using Monte Carlo Simulation and Pinnacle3® TPS

Purpose: We aim to provide accurate proton dose calculations for ocular tumors and adjacent critical organs using intensity modulated proton therapy (IMPT) using a human anatomy‐based Monte Carlo model. Dose is simulated using Monte Carlo code MCNPX and compared to standard photonIMRT planning using Pinnacle3® TPS. Method and Materials: The human anatomy model was adapted from the Visible Human Project from the National Library in Medicine. Sectioned images were assigned physical properties. Two independent trials delivering 90% prescription dose to 100% tumor volume were developed using IMRT and IMPT, respectively. Dose profiles for each transverse, sagittal and coronal view of the model were provided for evaluation. Both treatment plans were optimized to deliver maximum dose to the tumor and minimize dose elsewhere. The dose volume histograms for the PTV (tumor), eye, lens, optic nerve, lacrimal gland, brain, chiasm, and pituitary gland were compared between IMRT and IMPT, respectively. Results: IMPT delivered superior isodose coverage to all tissues. Comparing IMRT and IMPT, the mean dose was 4499 cGy and 4750 cGy‐Eq (PTV), 2334 cGy and 1700 cGy‐Eq (eye), 2705 cGy and 1330 cGy‐Eq (lens), 156 cGy and 181 cGy‐Eq (optic nerve), 142 cGy and 23 cGy‐Eq (lacrimal gland), 21 cGy and 0.0 cGy‐Eq (brain), 31 cGy and 0.0 cGy‐Eq (chiasm), and 43 cGy and 0.00 cGy‐Eq (pituitary gland), respectively. The PTV was well covered by 90% isodose to 100% of the tumor volume with an average % prescription dose of 99.9% and 105.6 % for IMRT and IMPT, respectively. Conclusions: IMPT provided conformal dose to the ocular tumor and significantly spared dose to critical organs compared to IMRT. The human‐anatomy dose model performs very well in dose calculation; however, further validation using additional human anatomy‐based models and more specified proton source configuration is needed for optimization purposes.
Foundations of retention in partition chromatography

The connection between the observable output in column chromatography (retention time, retention volume, retention factor, separation factor, etc.) and system properties (hold-up volume, pressure, temperature, isotherm behavior, etc.) is discussed from a practical and mechanistic perspective for gas-liquid chromatography, reversed-phase liquid chromatography, supercritical fluid chromatography, micellar electrokinetic chromatography, and capillary electrochromatography. The unifying feature of these techniques is that retention can be described by a partition model, although not always exclusively. When over simplistic system models are used to explain variation in retention parameters they frequently mask the true reasons for poor repeatability and difficulties in transfer between system. Methods employing relative retention afford higher precision but may contain residual uncorrected errors. For those systems with several separate mechanisms contributing to retention the effective retention parameters can no longer be interpreted by simple partition models. The broadly based and practically focused material in this article affords an illustration of the often complicated relationship between system properties and retention, and the dangers that lurk in simplified retention models if the validity of their underlining approximations is not appropriate for the system under study.
Nuclear Magnetic Resonance (NMR) Imaging: Potential Impact On Medical Diagnosis And Digital Data Communications

Nuclear magnetic resonance is a phenomenon which allows the generation of high quality medical images including the traditional transverse, coronal, and sagittal perspectives, while utilizing no ionizing radiation and without any known adverse biological effect. In addition, NNR imaging and diagnostic techniques allow the generation of basic chemical/pathophysiological measurements which have great promise to enhance the accuracy of medical diagnosis by providing more specific diagnostic information.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A far infrared study of the (0, 11, 0) state of ArD35Cl

A total of 36 transitions to the Π bending state of the title compound were observed and are listed
Endotoxemia and IL-1β Stimulate Mucosal IL-6 Production in Different Parts of the Gastrointestinal Tract

Abstract Background. In recent studies, sepsis and endotoxemia were associated with increased IL-6 production in mucosa of the jejunum. We tested the hypothesis that endotoxemia in mice stimulates mucosal IL-6 production in other parts of the gastrointestinal tract as well and that the enterocyte is a source of mucosal IL-6. In addition, we examined the effects of TNFα and IL-1β on mucosal IL-6 production. Materials and Methods. Endotoxin (12.5 mg/kg) was injected subcutaneously in mice. Control mice were injected with a corresponding volume of sterile saline. After 4 h, IL-6 levels were determined in mucosa of stomach, jejunum, ileum, and colon and in plasma and liver. In a second series of experiments, immunohistochemistry was performed of jejunal mucosa to determine in which cell type IL-6 was expressed. Finally, 100 μg/kg of human recombinant TNFα or human recombinant IL-1β was injected intraperitoneally in mice and IL-6 levels were determined in plasma and tissues after 4 h. Results. Endotoxemia resulted in increased mucosal IL-6 levels in small and large bowel but in reduced IL-6 levels in gastric mucosa. Immunohistochemistry of jejunal mucosa showed that IL-6 was expressed mainly in the enterocyte and in a few cells of the lamina propria. Treatment of mice with TNFα reduced IL-6 levels in gastric mucosa whereas IL-1β increased IL-6 levels in mucosa of small intestine. Conclusion. Mucosal IL-6 production during endotoxemia is differentially regulated along the gastrointestinal tract. Both TNFα and IL-1β may be involved in the regulation of gastrointestinal IL-6 production during endotoxemia.
Multiquantum rotational transitions in the mechanism of vibrational energy exchange: Application to CO*-CO

Abstract The present study introduces a simplified method for treating method for treating vibrational-rotational coupling during the collisional exchange of energy. This rotational coupling modifies the vibrational energy mismatch, ω 0 and is a dominant effect, working to make the actual energy mismatch smaller than the apparent energy discrepancy. The calculation is applied to the analysis of the CO * -CO system and it demonstrates the effect of collisions involving transitions in which Δ J >1.
Prothrombin G20210A polymorphism and thrombophilia.

Recently, a single mutation in the 3'-un of region of the prothrombin gene was reported, resulting in a G-to-A substitution. This finding added to the growing list of genetic disorders thought to be responsible for familial thrombophilia. Although most studies generally agree about the increased risk of venous thrombosis in individuals carrying this mutation, its role in the first event of venous thromboembolism and in recurrent events is unclear. Even less clear is the role this mutation has in the formation of arterial thrombosis (including coronary artery disease and cerebral ischemia) due to contradicting results of studies. This mutation has important clinical implications since it is a common cause of genetic thrombophilia, second only to the factor V Leiden mutation. However, the mutation by itself may not be enough to trigger disease because thromboembolic disease is now generally accepted as a multifactorial disorder. Careful evaluation of this mutation will augment the clinician's ability to stratify systematically an individual's risk of developing spontaneous thrombosis.
Classification of depressive disorders in the DSM-V: Proposal for a two-dimension system.

The number of categories and specifiers for mood disorders has increased with each successive edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM). Many of these categories and specifiers can be viewed as an effort to map the various permutations of severity and chronicity that characterize the depressive disorders. However, this has resulted in a system that (a) is unnecessarily complex and unwieldy, (b) has created problems with artificial distinctions between categories and artifactual comorbidity, and (c) at the same time obscures what may be more fundamental distinctions. A potentially useful and more parsimonious approach to capturing much of the heterogeneity of depressive disorders is to classify the depressive disorders along 2 dimensions, 1 reflecting severity and the other, chronicity. Considerations in the development of these dimensions are discussed, and a set of examples is presented. Although further research and discussion are needed to determine the optimal form of these dimensions, the next edition of the DSM should consider replacing many of the existing categories and specifiers for depressive disorders with the simpler approach of classifying depressive disorders using the 2 dimensions of severity and chronicity.
Histologic Study of Oral Mucosa Wound Healing: A Comparison of a 6.0‐ to 6.8‐µm Pulsed Laser and a Carbon Dioxide Laser

Incisional wound healing in the canine oral mucosa was histologically monitored at 3, 7, and 14 days after incision. Healing was compared from a scalpel, a carbon dioxide (CO2) laser at 10.6 microm, and the Vanderbilt free-electron laser tuned to 6.0, 6.45, and 6.8 microm. A significant delay in wound healing was observed when incisions were made with the CO2 laser, probably attributable to the excess thermal damage caused by the continuous-wave laser beam. When using the short pulsed, free-electron laser, a much smaller delay comparable to the scalpel wound healing was observed. This smaller delay tended to decrease with increasing tissue absorption. The results emphasize the greater importance of laser pulse duration rather than wavelength in relation to the subsequent wound healing.
Hop-count fairness-aware protocols for improved bandwidth utilization in WDM burst-switched networks

In this paper, we propose and evaluate two schemes for improving bandwidth utilization in optical burst-switched (OBS) networks employing timer-based burst assembly routines. The first scheme adjusts the size of the search space for a free wavelength in optical switches using a balancing formula that promotes throughput and hop-count fairness. The formula achieves controllable increase in the size of the search space either when the size of the burst increases or when the hop count of the traveling burst increases. The second scheme proactively discards bursts at the source network access station using a dropping probability matrix that satisfies certain horizontal and vertical constraints. The matrix assigns smaller dropping probabilities to bursts with larger sizes and longer lightpaths. The results of extensive performance tests to evaluate the two schemes and compare them with previous schemes for improving fairness and throughput are presented and discussed. The results show that the two schemes improve the throughput of optical OBS networks and enhance the hop-count fairness.
Hypoelastic soft tissues. Part I: Theory

Refinements are made to an existing hypoelastic theory developed by Freed [18, 19] for the purpose of modeling the passive response of soft, fibrous, biological tissues. Oldroyd’s [27] operators for convected differentiation and integration, which he derived from the tensor transformation law, are re-derived here from an integral equation defined in the polar configuration. Fields that obey these convected polar operators are said to be viable tensor fields, from which a new definition for strain and its rate are obtained and applied to a hypoelastic theory for tissue. Anisotropy is addressed through a material tensor, from which viable tensor fields describing fiber strain and strain rate are constructed. Material anisotropy and material constitution are handled separately for maximum flexibility. Isochoric hypoelastic models for isotropic, anisotropic, and fiber/matrix composite materials are derived. A material function is introduced to address special attributes that biological fibers impart on tissue behavior, four of which are proposed that represent various ways through which the fiber constituents might be described. Application to in-plane biaxial deformation is the focus of part II of this paper [23].
Reactive γ-ketoaldehydes formed via the isoprostane pathway disrupt mitochondrial respiration and calcium homeostasis

Isoketals (IsoKs) are gamma-ketoaldehydes formed via the isoprostane pathway of arachidonic acid peroxidation and are among the most reactive by-products of lipid peroxidation. IsoKs selectively adduct to protein lysine residues and are highly cytotoxic, but the targets and molecular events involved in IsoK-induced cell death are poorly defined. Our previous work established that physiologically relevant aldehydes induce mitochondrial dysfunction (Kristal et al., J. Biol. Chem.271:6033-6038; 1996). We therefore examined whether IsoKs induced mitochondrial dysfunction. Incubation of mitochondria with synthetic IsoKs in the presence or absence of Ca(2+) was associated with alterations in mitochondrial respiration, membrane potential (DeltaPsi), and pyridine nucleotide redox state. IsoKs dose dependently (0.5-4microM) accelerated liver mitochondria swelling induced by low concentrations of Ca(2+) and Zn(2+) or by the prooxidant tert-butylhydroperoxide, and release of cytochrome c, with similar observations in heart/brain mitochondria. The mitochondrial permeability transition (mPT) inhibitor cyclosporine A delayed IsoK-induced mitochondria dysfunction. The actions of IsoKs are consistent with interactions with cytochrome c, a protein rich in lysine residues. Direct reaction of IsoKs with select lysines in cytochrome c was demonstrated using high-resolution mass spectrometry. Overall, these results suggest that IsoKs may, in part, mediate their cytotoxic effects through induction of the mPT and subsequent activation of downstream cell death cascades.
The University of North Carolina caries risk assessment study: caries increments of misclassified children

The University of North Carolina caries risk assessment was conducted between 1986 and 1989 with 5000 children initially in grades 1 and 5 from low fluoride sites in South Carolina and Maine. Clinical, microbiologic, behavioral, and demographic factors served as independent variables used in logistic multiple regression models to determine the predicted caries risk classification of each child. The 3-yr DMFS increment of each child was the dependent variable, and the 20-25% of those in each cohort with the highest increment were considered the high risk group. Sensitivity and specificity values averaged 0.60 and 0.83 respectively, indicating the misclassification of substantial numbers of children. This paper reports analysis of the DMFS increments of the misclassified children. The majority of children had DMFS increments within one or two surfaces of the classification cut points. Many false negative children had increments composed entirely of filled surfaces, often of minimal extent and without evidence of previous decay. Many false positive children had increments composed of decayed surfaces and would have benefitted from being identified as high risk and assigned to a preventive program. Other false positive children had sealants placed after the baseline examination that undoubtedly reduced their true increment. It is concluded that the consequences of misclassification are not serious for most children in this study.
Mechanisms of hepatic triglyceride accumulation in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic lipid accumulation in the absence of excess alcohol intake. NAFLD is the most common chronic liver disease, and ongoing research efforts are focused on understanding the underlying pathobiology of hepatic steatosis with the anticipation that these efforts will identify novel therapeutic targets. Under physiological conditions, the low steady-state triglyceride concentrations in the liver are attributable to a precise balance between acquisition by uptake of non-esterified fatty acids from the plasma and by de novo lipogenesis, versus triglyceride disposal by fatty acid oxidation and by the secretion of triglyceride-rich lipoproteins. In NAFLD patients, insulin resistance leads to hepatic steatosis by multiple mechanisms. Greater uptake rates of plasma non-esterified fatty acids are attributable to increased release from an expanded mass of adipose tissue as a consequence of diminished insulin responsiveness. Hyperinsulinemia promotes the transcriptional upregulation of genes that promote de novo lipogenesis in the liver. Increased hepatic lipid accumulation is not offset by fatty acid oxidation or by increased secretion rates of triglyceride-rich lipoproteins. This review discusses the molecular mechanisms by which hepatic triglyceride homeostasis is achieved under normal conditions, as well as the metabolic alterations that occur in the setting of insulin resistance and contribute to the pathogenesis of NAFLD.
Hyperinducibility of Hypoxia-responsive Genes without p53/p21-dependent Checkpoint in Aggressive Prostate Cancer

Hypoxia limits tumor growth but selects for higher metastatic potential. We tested the functional activity of hypoxia-inducible factor-1 (HIF-1) in prostate cell lines ranging from normal epithelial cells (PrEC), hormone-dependent LNCaP, hormone-independent DU145, PC-3 to highly metastatic PC-3M cancer cell lines. We found that HIF-1-stimulated transcription was the lowest in PrEC and LNCaP cells and the highest in PC-3M cells. The induction by hypoxia of the HIF-1 dependent genes Cap43 and GAPDH was the highest in the most aggressive PC-3M cancer cells. Because these advanced prostate cancer cell lines have lost p53 function, this further shifts a balance from p53 to HIF-1 transcriptional regulation, and a high ratio of HIF-1-dependent:p53-dependent transcription was a marker of the advanced malignant phenotype. Transient transfection of HIF-1alpha expression vector induced transcription from p21 promoter construct in prostate cancer cell lines. Furthermore, hypoxia slightly induced p21 mRNA in these cells. However, neither expression of p21 nor hypoxia caused growth arrest in PC-3M cells. Therefore, high inducibility of HIF-1-dependent genes, loss of p53 functions with high ratio of HIF-1-dependent:p53-dependent transcription, and loss of sensitivity to p21 inhibition is a part of hypoxic phenotype associated with aggressive cancer behavior.
Distribution and Solubility of Radionuclides and Neutron Absorbers in Waste forms for Disposition of Plutonium Ash and Scraps, Excess Plutonium, and Miscellaneous Spent Nuclear Fuels

The initial goal of this project was to investigate the solubility of radionuclides in glass and other potential waste forms for the purpose of increasing the waste loading in glass and ceramic waste forms. About one year into the project, the project decided to focus on two potential waste forms - glass at PNNL and itianate ceramics at the Australian Nuclear Science and Technology Organisation (ANSTO).
Automatic construction of semantic lexicons for learning natural language interfaces

This paper describes a system, WOLFIE (WOrd Learning From Interpreted Examples), that acquires a semantic lexicon from a corpus of sentences paired with semantic representations. The lexicon learned consists of words paired with meaning representations. WOLFIE is part of an integrated system that learns to parse novel sentences into semantic representations, such as logical database queries. Experimental results are presented demonstrating WOLFIE's ability to learn useful lexicons for a database interface in four different natural languages. The lexicons learned by WOLFIE are compared to those acquired by a similar system developed by Siskind (1996).
Compressing texture coordinates with selective linear predictions

We describe a strategy for efficient predictive compression of texture coordinates. Previous works in mesh compression often claim that this mesh property can simply be compressed with the same predictor that is already used for vertex positions. However, in the presence of discontinuities in the texture mapping such an approach results in unreasonable predictions. Our method avoids such predictions altogether. Rather than performing an unreasonable prediction, we switch to a less promising, but at least reasonable predictor. The resulting correctors are then compressed with different arithmetic contexts.
Predicting distribution system performance against regulatory reliability standards

In order to ensure that the changing utility environment does not adversely affect the reliability of electric power supplied to customers, several state regulatory agencies have started to prescribe reliability standards-minimum reliability levels-to be maintained by electric power distribution companies. The standards are based on reliability indexes computed from historical outage data. The reliability indexes vary from year to year because of the statistical variation in the number of customer interruptions and the duration of such interruptions. To be effective, the reliability standards adopted must identify feeders that consistently perform poorly, while being insensitive to those that occasionally have poor reliability. This paper employs a duration based Monte Carlo simulation to explore the predicted impact of various reliability standards on a large practical distribution system. The sensitivity of different standards to differences in system size and component failure rate is also explored.
Unsupervised and Semi-supervised Learning of Tone and Pitch Accent

Recognition of tone and intonation is essential for speech recognition and language understanding. However, most approaches to this recognition task have relied upon extensive collections of manually tagged data obtained at substantial time and financial cost. In this paper, we explore two approaches to tone learning with substantially reductions in training data. We employ both unsupervised clustering and semi-supervised learning to recognize pitch accent in English and tones in Mandarin Chinese. In unsupervised Mandarin tone clustering experiments, we achieve 57-87% accuracy on materials ranging from broadcast news to clean lab speech. For English pitch accent in broadcast news materials, results reach 78%. In the semi-supervised framework, we achieve Mandarin tone recognition accuracies ranging from 70% for broadcast news speech to 94% for read speech, outperforming both Support Vector Machines (SVMs) trained on only the labeled data and the 25% most common class assignment level. These results indicate that the intrinsic structure of tone and pitch accent acoustics can be exploited to reduce the need for costly labeled training data for tone learning and recognition.
Simple silhouettes for complex surfaces

Complex meshes tend to have intricate, detailed silhouettes. This paper proposes two algorithms for extracting a simpler, approximate silhouette from a high-resolution model. Our methods preserve the important features of the silhouette by using the silhouette of a coarser, simplified mesh as a guide. Our simple silhouettes have significantly fewer edges than the original silhouette, while still preserving its appearance.
General model for the steady-state response properties of fiber-optic ammonia gas sensors

A mathematical model is derived to describe the steady-state response properties of the fiber-optic ammonia sensor. Unlike our previous model, the present model permits any concentration of total ammonia nitrogen initially present in the internal solution of the sensor. A cubic equation is solved to give the magnitude of the nonprotonated form of the indicator dye under equilibrium conditions. For the first time, the effect of the initial ammonia nitrogen concentration in the internal solution is evaluated. In addition, the response equation is differentiated with respect to the sample ammonia concentration to give an expression that can be used to evaluate the effects of critical experimental parameters on the measurement sensitivity. This model is verified by comparing predicted and actual responses for several different fiber-optic sensor configurations. The model is used to generate surface maps that allow evaluation of the interrelationships between key experimental parameters such as the indicator concentration, sample ammonia concentration, internal ammonium chloride concentration and indicator acid dissociation constant. Results of this analysis indicate that optimal responses and maximal sensitivity require careful selection of values for these parameters.
Palladium catalyzed ethylene‐carbon monoxide alternating copolymerization

A new [(PPh2CH2CH2CH2PPh2)Pd(CH3CN)2](BF4)2/CH3OH catalyst for olefin/carbon monoxide alternating copolymerization has been found which is far more active and more stable than previous monodente phosphine Pd catalysts. Methanol is a coinitiator as well as a chain transfer agent. Protonic acid is not a coinitiator but causes chain transfers. In the absence of methanol, the copolymerization was characterized by long induction period and slow rate © 1992 John Wiley & Sons, Inc.
The effect of aqueous solvation upon alpha-helix formation for polyalanines.

The incremental free energies of aqueous solution for acetyl(ala) NNH2 in its extended unfolded and R-helical conformations are compared using the SM5.2 solvation method of Cramer and Truhlar. A combination of density functional theory (DFT) at the B3LYP/D95(d,p) and AM1 has been employed using the ONIOM method. The incremental solvation energies of R-helical structures are very similar for both ONIOM and AM1 optimized structures as these structures do not significantly change upon solution. However, the conformations of the unfolded peptides change from extended ‚-strand to polyproline II conformations upon aqueous solution. The incremental solvation free energy per residue of the polyproline II structure is about 2 kcal/mol/residue greater than that for the R-helix, representing an upper limit for the difference between the solvation energies. However, most of this difference disappears when the energy required to distort the optimized gas-phase extended ‚-strand structure to the optimized polyproline II solution structure is included in the analysis, leaving an estimated difference in incremental solvation free energy of 0.3 -0.5 kcal/mol favoring the unfolded structure. The solution structure sacrifices the stability derived from the intramolecular C5 H-bonds for more favorable interactions with the aqueous solvent.
Probability of call and likelihood of the call feature in a corporate bond

Abstract This paper suggests a new way of predicting the likelihood of a corporate bond being callable. We compute the probability that a bond, if callable, would actually be called within a certain period. We also hypothesize a positive relationship between this probability and the likelihood of the bond being issued with a call feature. Comparative static results yield the following empirical implications: the likelihood of a call feature should be an increasing function of coupon rate, corporate tax rate and leverage ratio, and a decreasing function of interest rate and firm risk (volatility). Tests with recently issued corporate bonds provide fairly strong support for the model’s predictions.
Season-to-Season Cyclone Frequency Prediction

Abstract Winter and summer half-year cyclone frequencies for eastern North America and the western North Atlantic were tabulated for 2.5° latitude by 5° longitude grid cells for the years 1885–1980. Correlation matrix eigenvectors were calculated for matrices of both the winter and summer data for a dependent set of years (1885–1959). The first four eigenvectors for winter are highly similar in form to their summer counterparts and are correlated with them in the time domain. These correlations permit a season-in-advance estimation of half-year cyclone frequencies. Forecast skill for independent years (1960–1980) in both winter and summer averages 75% relative to the 1885–1959 means as forecasts. The multivariate statistical forecast scheme outperforms both simple and damped persistence in addition to raw climatology. The climatological persistence from which the forecast skill results is shown to have both intermediate- and low-frequency components.
Improving emission in nanorod arrays using quasi-aperiodic inverse design (Presentation Recording)

Photonic structure plays a significant role in determining the brightness and efficiency of nanoemitter systems. Using photonic crystal slabs it is possible to affect these quantities in various ways. First, positioning a leaky mode near the emission frequency allows more light to be extracted from within the slab. Second, concentrating high electric field intensity near emitter locations significantly enhances the spontaneous emission rate. However, a large body of work has suggested these two contributing factors are in competition, making it difficult to simultaneously achieve high electric field intensity and light extraction. In previous work, we identified one mode in an array of GaN nanorods which exhibited a 25X enhancement in extracted power, relative to a uniform slab. However, the mode was uncoupled to normal radiation and, consequently, produced a sharp dip in extraction efficiency. Here, we improve upon the previous design by investigating a new class of quasi-aperiodic nanorod array structures. Using an inverse design algorithm, we identify one optimized structure which achieves maximum theoretical light extraction while maintaining a high spontaneous emission rate. Overall, the optimized structure achieves a 48% increase in extracted power and a 20-48% increase in external quantum efficiency relative to the previous periodic design.