cssi/SciSciGPT-SciSciNet huggingface dataset:
Determination of 15-keto-13,14-dihydro-metabolites of PGE2 and PGF2α in plasma using high performance liquid chromatography and gas chromatography-mass spectrometry*

A method is described for the measurement of 15-keto-13,14-dihydrometabolites of PGE2 and PGF2alpha in peripheral human plasma. This involves purification by high performance liquid chromatography followed by determination of levels by combined gas chromatography-mass spectrometry using tetradeuterated analogs of the metabolites as internal standards. The levels of these metabolites in plasma are considered to be a more reasonable index of the entry of PGE2 and PGF2alpha into peripheral blood than are the levels of the corresponding primary prostaglandins. The endogenous levels of 15-keto-13, 14-dihydro-PGE2 and 15-keto-13,14-dihydro-PGF2alpha found in peripheral plasma are 33 +/- 10 pg/ml (SD; n=6) and 40 +/- 16 pg/ml (SD; n=6), respectively.
Late-life paranoia: Possible association with early trauma and infertility

We have collected data on 39 persons with late-life onset of paranoid symptoms, all but two of whom are women. We identified a subset of nine patients that met the criteria for delusional disorder. This group differed significantly from both demented and long-term schizophrenic patients on a number of variables. There was only one live birth among these nine women; more than half were refugees or holocaust survivors; there was an absence of a predicted sensory loss; and the manifestation of the paranoia was qualitatively different. Several issues are discussed: there is a late-life delusional state that is neither schizophrenia nor dementia; the paranoia in these delusionally disordered patients cannot be accounted for exclusively by the social isolation hypothesis; there is an interaction among early trauma, the absence of children, and the appearance of paranoid ideation late in life.
Mode-specific effects in resonant infrared ablation and deposition of polystyrene

Low molecular weight polystyrene (∼10 kDa) was ablated with a free-electron laser at 3.31 and 3.43 μm and deposited as thin films on Si(100) substrates. The vibrational bands at 3.31 and 3.43 μm correspond to phenyl-ring CH and backbone CH2 modes, respectively. Even though the absorption coefficients of these two modes are nearly the same, the ablation yield was approximately 50% higher for the ring-mode excitation compared with the backbone mode. Based on spectral line width, the ring-mode lifetime is approximately triple that of the backbone mode, leading to a higher spatiotemporal density of vibrational excitation that more effectively disrupts the relatively weak Van der Waals bonds between neighboring polymer chains and consequently to higher ablation efficiency of the ring mode. Molecular weight assays of the deposited films showed that relatively little bond scission occurred and that the average molecular weight of the films was similar to that of the starting material.
Disgust propensity and sensitivity: Differential relationships with obsessive-compulsive symptoms and behavioral approach task performance

Abstract Research indicates that disgust propensity (DP; the tendency to respond with disgust) and disgust sensitivity (DS; the tendency to experience disgust as aversive) are differentially correlated and predictive of specific anxiety disorder symptoms. Based on this distinction, we sought to investigate the relationship of disgust indices to specific obsessive-compulsive (OC) symptoms in a large, non-clinical sample (N=755). DP significantly predicted washing symptoms even after controlling for the influence of gender, negative effect and anxiety sensitivity, whereas DS did not. Additionally, in a subset of participants (N=152) we examined the indices of DP and DS in the prediction of in vivo disgust and avoidance on a contamination-based behavioral approach task (BAT) while controlling for the aforementioned covariates and OC symptoms. Analyses revealed that elevated DP significantly predicted heightened disgust and greater behavioral avoidance on the BAT. Our data suggest important conceptual and phenomenological differences between the two disgust constructs: DP is more associated with avoidant action tendencies to repugnant materials whereas DS is linked with more general emotional sensitivity.
Low School Engagement and Sexual Behaviors among African American Youth: Examining the Influences of Gender, Peer Norms, and Gang Involvement

This research examined whether negative peer influences (i.e., norms favoring risky sex and drug use and gang involvement) mediated the relationship between school engagement (i.e., grade point averages [GPAs] obtained from school records and student-teacher connectedness) and sexual behaviors (i.e., sexual debut, sex without condoms, group sex, and sex while using drugs) among African American high school adolescents, and whether these relationships varied by gender. Five hundred sixty-three high school adolescents (ages 13 to 19) completed self-administered questionnaires that assessed school engagement markers (GPAs obtained from student records, and student-teacher connectedness), peer influences, sexual debut, and risky sex (sex without condoms, group sex, and sex while using drugs). Major findings for boys indicate that GPA was negatively associated with both sexual debut and risky sex. Additionally, the relationship between student-teacher connectedness and risky sex was mediated by gang involvement. For girls, higher GPAs were associated with fewer norms favoring risky sex and drug use and such norms were associated with sexual debut. Moreover, the relationship between GPA, sexual debut and risky sex was mediated by risky peer norms. Intervention programs to delay sexual debut and reduce risky sex among youths should attend to the gendered ways through which such behaviors occur.
Titanium silicide/silicon nonohmic contact resistance for NFET's, PFET's, diffused resistors, and NPN's in a BiCMOS technology

Self-aligned titanium silicide is often used to minimize the polysilicon and diffusion sheet resistances. Current is delivered to the channel of FET's, the body of diffused resistors, and into the active region of NPN's through the titanium silicide/silicon interface. This contact resistance can represent a significant fraction of the total device resistance for devices of small dimensions, and contributes to a loss in circuit performance. The impedance of this interface is a function of the doping level in the silicon immediately below the interface, and this doping level is a sensitive function of the heat applied to the structure after the formation of the silicide. The correspondence of FET series resistance, emitter resistance, the diffused resistor end effects and the non-ohmic nature of a contact after heat is applied is presented. Use of a rapid thermal anneal to obtain the requisite silicide characteristics while minimizing the impact on the contact resistance is demonstrated for a 0.8-/spl mu/m BiCMOS technology. >
Topics to ponder: Part-time practice and pay parity.

Abstract Background: The medical profession has undergone a significant demographic change, with a dramatic increase in the number of women applying to medical school and practicing medicine. Objectives: In recognition of the changing demographics in the medical profession, the American Medical Association's Women Physicians Congress (AMA-WPC) conducted a members' survey to identify the issues affecting women physicians and to ascertain certain practice characteristics. Methods: In 2008, an e-mail survey link was sent to a randomly selected nationwide sample of 4992 WPC members, and a second, identical survey was sent to 596 female AMA members, utilizing the Epocrates database (Epocrates, Inc., San Mateo, California). Two e-mail reminders were sent for the first survey, which had a 15% response rate. A quota of 148 physicians was received within 4 days and was utilized to interpret results from the second survey. Results: Achieving work-life balance was a significant concern for 91% of the respondents (n = 884). Half of the respondents believed that pay is gender neutral, and 28% indicated that they were “somewhat or very concerned about sexual harassment”. When queried regarding practice patterns, 29% of respondents indicated that they had worked part-time at some point during their careers. Conclusions: In this survey, women physicians indicated that gender pay disparity and sexual harassment remain important issues in the medical profession. Less than a third of respondents had ever worked part-time, which should be a consideration for physician workforce studies. Barriers to part-time practice may exist.
Dependent Stressful Life Events and Prior Depressive Episodes in the Prediction of Major Depression: The Problem of Causal Inference in Psychiatric Epidemiology

Context Most environmental risk factors for psychiatric disorders cannot be studied experimentally, making causal attributions difficult. Can we address this question by using together 2 major methods for causal inference: natural experiments and specialized statistical methods? Objective To determine the causal relationship between dependent stressful life events (dSLEs) and prior depressive episodes (PDEs) and major depression (MD). Design Assessment of risk factors and episodes of MD at interview. Statistical analyses used the co-twin control and propensity score–matching methods. Setting General community. Participants Four thousand nine hundred ten male and female twins from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. Main Outcome Measure Episodes of MD. Results We found that dSLEs were strongly associated with risk for MD in female (odds ratio [OR], 5.85) and male (4.55) twins in the entire sample and, at considerably lower levels, in female (2.29) and male (2.19) monozygotic twins discordant for dSLE exposure. A case-control sample matched on propensity score showed a moderate association in female (OR, 1.79) and male (1.53) twins. A PDE strongly predicted risk for MD in female (OR, 3.68) and male (5.20) twins in the entire sample. In monozygotic pairs discordant for exposure, the association was weaker in male (OR, 1.41) and absent in female (1.00) twins. A case-control sample matched on propensity score showed a moderate association between PDE and depressive episodes in male (OR, 1.58) and female twins (1.66). Conclusions Although dSLEs have a modest causal effect on the risk for MD, a large proportion of the observed association is noncausal. The same pattern is seen for PDEs, although the causal impact is somewhat more tenuous. For environmental exposures in psychiatry that cannot be studied experimentally, co-twin control and propensity scoring methods—which have complementary strengths and weaknesses—can provide similar results, suggesting their joint use can help with the critical question of causal inference.
Low-temperature heat capacity of antiferromagnetic ternary rare-earth iron silicides M 2 Fe 3 Si 5

The low-temperature heat capacity of antiferromagnetic ternary iron silicides ${M}_{2}{\mathrm{Fe}}_{3}{\mathrm{Si}}_{5}$ ($M=\mathrm{Sm}, \mathrm{Gd}\ensuremath{-}\mathrm{Yb}$) has been measured from 0.5 to 30 K. Antiferromagnetic ordering temperatures range from 1.06 to 10 K for these materials including multiple magnetic transitions in ${\mathrm{Sm}}_{2}$${\mathrm{Fe}}_{3}$${\mathrm{Si}}_{5}$, ${\mathrm{Tb}}_{2}$${\mathrm{Fe}}_{3}$${\mathrm{Si}}_{5}$, and ${\mathrm{Er}}_{2}$${\mathrm{Fe}}_{3}$${\mathrm{Si}}_{5}$. Magnetic ordering via the Ruderman-Kittel-Kasuya-Yosida interaction is indicated, even in the presence of large crystalline electric field effects. Entropy considerations indicate the magnetic ground state is a doublet in all of these materials except ${\mathrm{Gd}}_{2}$${\mathrm{Fe}}_{3}$${\mathrm{Si}}_{5}$. Anomalous behavior is observed with respect to spin-wave and nuclear contributions to the total heat capacity, crystalline electric field effects, and critical behavior.
Characterization of an immortalized cell line from a patient with epidermolytic hyperkeratosis.

The most frequent mutation that causes the autosomal dominant skin disease epidermolytic hyperkeratosis (EHK) is an arginine to histidine substitution at position 10 in the 1A segment of the rod domain of keratin 10. As an initial step toward developing a strategy for treating EHK, a cell line, EH18-1, was established after keratinocytes derived from an EHK patient with this mutation were immortalized by a recombinant retrovirus encoding the E6 and E7 genes of human papillomavirus type 18. EH18-1 cells synthesize considerable amounts of keratin 10 mRNA and protein when maintained in either submerged cultures or in organotypic cultures. When grown in organotypic culture, EH18-1 cells form multiple layers and express keratin 10 and filaggrin predominantly in the upper layers. Thus, the EH18-1 cell line exhibits several morphological and biochemical markers of tenninal epidermal differentiation. A sentiquantitative reverse transcriptase polymerase chain reaction assay for keratin 10 mRNA was developed to distinguish between expression of the normal and the mutant alleles. The EH18-1 keratinocyte cell line will be useful in developing protocols for gene therapy of ENK that may be monitored by reverse transcriptase polymerase chain reaction of either allele.
Supramolecular control of photochemical enantiomeric induction and radical pair recombination in zeolites

Abstract Geminate radical pairs are formed from the α-photocleavage of aryl ketones within the supercage of zeolites which has been modified with chiral guest molecules. Herein, we report the supramolecular structure and dynamic control of both enantnantiomeric selectivity and probability of the recombination of the radical pairs.
Inhibition of adipose conversion of BALB/c 3T3 cells by interferon and 12-O-tetradecanoylphorbol-13-acetate.

Abstract The adipose conversion of BALB/c 3T3 preadipose cells is inhibited by interferon; this inhibition is directly correlated with the interferon concentration. In cultures treated with low doses of interferon and the tumor promoter 12-O-tetradecanoylphorbol-13-acetate, another inhibitor of adipose conversion (Diamond et al., 1977), the two compounds act synergistically to block differentiation. Several lines of evidence suggest that the compounds differ in the mechanism by which they inhibit adipose conversion.
Auxin Transport in Zea mays Coleoptiles II. Influence of Light on the Transport of Indoleacetic Acid-2-14C

The effect of bilateral irradiation with white light (1000 Meter Candle Sec) on the basipetal transport of auxin has been investigated. Illumination of either the intact shoot or the excised coleoptile tip of the Zea seedling, decreased the amount of diffusible auxin obtained from the tip, and decreased Avena curvature response to unilaterally applied indoleacetic acid. Irradiation of the intact Zea seedling did not affect the absorption of 14C-labeled indoleacetic acid from an agar block subsequently placed on the decapitated coleoptile. However, light caused a significant decrease in the amount of labeled auxin basipetally transported, without affecting materially the velocity of that transport. These and other observations are interpreted as support for the hypothesis that the primary hormonal phenomenon in first-positive phototropism is a light-induced impairment in the basipetal transport of auxin.
The Market for Corporate Control and Firm Innovation

This research examines an integrated theoretical model that explains how strategies for participating in the market for corporate control (acquisitions and divestitures) affect internal control mec...
Is alcohol induced poikilothermia mediated by 5-HT and catecholamine receptors or by ionic set-point mechanism in the brain?

Abstract In adult male Sprague-Dawley rats, stainless steel guide cannulae were implanted stereotaxically in either the lateral or third cerebral ventricle. Postoperatively, each animal was maintained at an ambient temperature of 22°C. Just prior to the intragastric gavage of 4.0 g/kg ethyl alcohol (20% solution) individual animals were fitted with a colonic thermistor probe. Then, control CSF, a monoaminergic receptor antagonist, or a Ca ++ ion chelating agent, EGTA, was infused into either the lateral or third ventricle (ICV) in a volume of 10.0 μl. Phentolamine (20.0 μg), butaclamol (10.0 μg), or methysergide (20.0 μg) injected ICV all failed to prevent the thermolytic action of alcohol. The fall of 1.5 to 2.0°C in the rat's colonic temperature, ordinarily caused by alcohol, was the same as that without the antagonists and lasted 3.0 to 4.0 hrs. EGTA infused into the rat's lateral cerebral ventricle also did not interfere with alcohol's poikilothermic action. However, EGTA infused into the third cerebral ventricle completely blocked alcohol's effect in lowering the body temperature of the rat. These results suggest that: (1) alcohol's profound effects on body temperature are not mediated by 5-HT, norepinephrine or dopamine pathways which are thought to underlie the mechanisms in the hypothalamus for thermoregulation; and (2) the temperature set-point mechanism, controlled by the ratio of diencephalic Na + to Ca ++ ions, is incapacitated by alcohol. Restoration of the ratio in the diencephalon by the direct, local chelation of Ca ++ ions thus eliminates alcohol's deleterious effects on body temperature.
MEASURING THE CRITICAL THICKNESS OF THIN METALORGANIC PRECURSOR FILMS

Successful application of sol-gel, metalorganic decomposition, or hydrothermal routes to ceramic thin films depends on the mechanical integrity of the precursor film. Above a critical thickness, a precursor film will crack or decohere from the substrate during drying. The cracking and thickness of thin metalorganic precursor films were simultaneously observed during drying using a standard optical microscope. Isochromatic color fringes produced by interference of reflected white light were used to monitor film thickness. The critical film thickness was determined by the color fringe corresponding to the thickness at which propagating cracks terminated. As a demonstration of the technique, the critical thickness of titanium di(isopropoxide) bis(ethyl acetoacetate) films was measured, showing increased critical thickness with the addition of small amounts of an elastomeric polymer.
Two sources of proactive interference in spatial working memory: Multiple effects of repeated trials on radial maze performance by rats

Rats were trained in 8- and 12-arm radial mazes. Each trial began with a study phase (forced choices of 4 arms). The trial ended after a 2-h delay in a test phase consisting of free choices among 8 arms; choices of the 4 arms not yet visited were correct (rewarded). Proactive interference (PI) was induced by an interference phase that occurred on some days 2 or 3 h prior to the study phase. In the PI-repetition condition, the interference phase consisted of forced choices of the 8 arms that were later presented in the study and test phases; in the PI-nonrepetition condition, the interference consisted of forced choices of the 4 arms that were correct during the test phase. Test-phase performance was most accurate in the No PI (single-trial) condition and least accurate in the PI-repetition condition. A second experiment showed that repetitions per se were not responsible for the PI; when the interference phase consisted only of choices of the same 4 arms later presented in the study phase, no PI was observed. These findings suggest two sources of PI. One source, measured by the difference between No PI and PI-nonrepetition conditions, appears to be a difficulty in discriminating the temporal order of visits to arms in the interference and study phases. The other source of PI, measured by the difference between the nonrepetition and repetition conditions, remains to be identified; some possibilities are discussed.
Performance Evaluation of a Catalytic Flat Plate Fuel Reformer for Hydrogen-Rich Reformate

A two-dimensional computational fluid dynamics (CFD) model is used for reforming methane with the help of catalytic combustion and reformation in a catalytic flat plate reformer. The two-dimensional approach makes the computational model more realistic by eliminating the uncertainties introduced by heat and mass transfer coefficients used in one-dimensional models. It also increased its capability to capture the effect of design parameters such as catalyst thickness, reaction rates, inlet temperature and velocity, and channel height has on producing high purity reformate gas. In order to carry out parametric studies related to various design parameters, in our present work, we simulate the entire flat plate reformer domain by considering full electro-kinetics that provide guidance for the practical implementation of such design. We chose different designs and operating conditions in such a way which makes possible to build a catalytic flat plate fuel reformer prototype. Based on the CFD results obtained in this study, we built a first generation catalytic flat plate fuel reformer prototype using the optimized design parameters. The performance of the fuel reformer prototype is tested with a 5-cell high temperature PEM fuel cell stack.Copyright © 2013 by ASME
Preparation of cationic polymer surfaces by grafting polymerization

A cationic polymer surface with extensive capacity for adsorption of anionic surfactants was prepared by graft polymerization of vinyl pyridine onto a plasma-treated polypropylene surface. The nitrogen was quaternized in order to obtain the cationic sites. The concentration dependence of adsorption from high eletrolyte solution of the anionic surfactant was similar to the one a solid surface from solutions with no added electrolyte. The hydrophobic contribution to the adsorption was experienced at surfactant concentrations far below its critical micellization.
Developmental changes in hepatic IGF-2 and IGFBP-2 mRNA levels in intrauterine growth-retarded and control swine

Abstract 1. 1. Significantly elevated levels of hepatic IGFBP-2 mRNA were detected in IUGR piglets at 90 days fetally and at birth ( P 2. 2. Developmentally, hepatic IGF-2 ( P P 3. 3. This study provides new information concerning hepatic expression of IGF-2 and IGFBP-2 in developing swine.
Early cardiac dysfunction in pediatric patients on maintenance dialysis and post kidney transplant

Background Children with advanced chronic kidney disease (CKD) frequently develop left ventricular (LV) hypertrophy. The extent of hypertrophy that results in cardiac dysfunction is unknown. Systolic function, routinely determined by ejection fraction (EF), is usually preserved in these patients. However, a decrease in EF represents an advanced cardiac dysfunction. We used cardiac magnetic resonance (CMR) and phosphorus-31 MR spectroscopy (31P MRS) to assess markers of cardiac dysfunction in young CKD patients.
Identification of Human Inertia Properties Using a Momentum-Based Approach

This paper presents a momentum-based approach for identifying the barycentric parameters of a human body. The human body is modeled as a multiple rigid-body dynamical system with a tree-type topology using the principle of impulse and momentum. Since the resulting impulse-momentum equations are linear in terms of the unknown barycentric parameters, these parameters can be easily solved using the least-square method or other well-understood solution techniques. The approach does not require measuring or estimating accelerations and internal forces because they do not appear in the impulse-momentum equations and, thus, the resulting identification procedure is less demanding on the measurement and also less sensitive to measurement errors in comparison with other existing methods derived based on Newton-Euler or Lagrangian equations. The momentum-based approach has been studied by dynamics simulations with the consideration of possible measurement errors. The study showed good results.
Patients with Bardet-Biedl syndrome have hyperleptinemia suggestive of leptin resistance.

Hyperleptinemia out of proportion to adiposity is found in Bardet-Biedl syndrome, consistent with the leptin resistance shown in mouse models of this ciliopathy.
Tryptophan availability as a control of hepatic pyridine nucleotide concentratioon in mice

Abstract A study in mice was initiated to determine whether tryptophan availability or alterations in tryptophan oxygenase ( L -tryptophan; oxygen oxido reductase; EC 1.13.1.12) activity regulated the conversion of tryptophan to NAD. A single intraperitoneal injection of varying amounts of tryptophan resulted in increases in hepatic tryptophan content, tryptophan oxygenase activity, NAD+, NADPH and NADPH concentrations which were proportional to the dose of this amico acid. This tryptophan stimulated rise in enzyme activity and in NAD content also occurred in adrenalectomized animals. In addition, injections of 300—500 mg of tryptophan per kg of body weight elicited a significant increase in the ratio of NAD+ to NADH. Allopurinol given simultaneously with tryptophan strongly depresssed tryptophan oxygenase activity yet did not decrease the rise in NAD. On the other hand, hydrocortisone and D,L -α-methyl-tryptophan increased tryptophan oxygenase activity without markedly augmenting NAD concentration. It would thus seem that NAD synthesis from tryptophan is regulated by substrate availability rather than by variations in tryptophan oxygenase activity.
Using the Alcohol Expectancy Questionnaire-Adolescent Form to predict college drinking: long versus short forms

This study reports the development of a short form of the Alcohol Expectancy Questionnaire-Adolescent Form, consisting of 27 items measuring expectations of enhanced social behavior and enhanced cognitive and motor functioning. The goals of this study are to examine whether the AEQ-A can be used in a college population and whether a shortened version is a reliable and valid substitute. The reliability and predictive validity of this instrument was assessed in a college population (N = 377) by replication of previous work predicting drinking styles from expectancies. Scale 2 of the short form predicted drinking styles as well as the seven long-form scales. The results suggest the new instrument will be useful in expediting future research.
Photodesorption dynamics of CO from Si(111) : the role of surface defects

Abstract Laser-induced desorption of CO from an ion beam etched and annealed Si (111) surface is reported. Stateresolved measurements of the desorbed CO reveal very high translational and vibrational energy contents, with the rotational excitation being quite low. The results suggest that the CO photodesorption is derived from CO bound to ion beam etch-induced active “defect” site(s) on the Si(111)7 × 7 surface that are only minimally influenced by either the ion beam etching conditions or the anneal. The very high translational energy in the CO implies desorption from active “defect” site(s) either in the very-near-surface region or on the surface. Comparison of the photoyields at 266 and 355 nm suggests that the desorption mechanism cannot be described using existing models for thermal- or carrier-mediated processes.
Instrumentation for the measurement of the variation, quantity, and quality of sun and sky radiation

Abstract Many biological responses, such as reproduction, differentiation and morphological development are regulated by radiant energy in particular wavelengths of the solar spectrum. Biologists are concerned with the influence of the spectral quality of natural daylight on these biological responses. Data, concerning spectral quality of daylight over a sufficient time period, required by biologists are usually not available. The described system will provide the information with sufficient accuracy and precision to discern small but significant changes. To produce such a monitoring system, a standardization program was evolved using the original Smithsonian solar standards and instruments. These were compared to each other and finally to commercial units which were used in the monitoring system. The system was designed so that data would be accurate at 0.01 ly min −1 and could be automated to give high precision readings every 3 min with errors less than 2 per cent.
Formation of a new bioactive glass-ceramic

A new bioactive glass-ceramic with a nominal composition of CaO (54.5), MgO (6.0), SiO2 (32.8), P2O5 (6.1) and CaF2 (0.6), by weight ratio, has been developed. The crystalline phases termed hydroxyfluoroxyapatite, akermanite, and wollastonite were found to be present simultaneously at a temperature of 930°C. Furthermore, no cracks appear after the bulk glass is crystallized. This newly developed glass-ceramic has an average flexural strength of 233 MPa and a fracture toughness of 2.95 MPa m1/2, which are higher values than for dense hydroxyapatite and known glass-ceramic. An apatite layer containing Ca, P and Si is formed on the surface after the glass-ceramic is soaked in a simulated body fluid for a short period of time, which is indicative of a high bioactivity.
Conversion of a human low-density lipoprotein receptor ligandbinding repeat to a virus receptor: Identification of residues important for ligand specificity

The amino-terminal region of the low-density lipoprotein receptor (LDLR) contains seven imperfect repeats of a cysteine-rich, roughly 40-aa module (LDL-A module) that are critical for apolipoprotein binding. LDL-A modules are found in numerous cell-surface and secreted proteins and are believed to mediate extracellular protein–protein interactions. The cellular receptor for subgroup A Rous sarcoma virus (RSV) contains a single LDL-A module that binds the RSV envelope protein and allows viral infection. To define residues in an LDL-A module responsible for ligand recognition, we used a gain of function assay by using a chimeric protein in which the LDL-A module of Tva was replaced with a highly homologous module from human LDLR (LDL-A4) and determined whether this chimera or mutants produced in it could mediate RSV infection. LDL-A4 does not function as an RSV receptor; however, systematic replacement of the nonconserved residues of the LDL-A4 module in the chimeric protein with the corresponding residues from Tva identified three residues sufficient to alter ligand specificity and convert LDL-A4 to an efficient viral receptor. Mutations of the corresponding residues in the Tva LDL-A module decreased both envelope binding and viral receptor function, confirming the importance of these residues in ligand recognition by this module. Analysis of the hLDL-A5 structure demonstrates that these three residues are clustered at one end of the LDL-A module. These results demonstrate that using a single LDL-A module in a gain of function assay is a useful model to investigate ligand recognition by this module.
The ultrastructure of antigen localization and virus-like particles in mouse spleen germinal centers

Abstract The localization of 125I-labeled human gamma globulin in mouse spleen germinal centers was studied by electron-microscopic autoradiography during the first 30 days of the primary immune response. Cells in the germinal centers which were consistently associated with a large number of silver grains exhibited clear voluminous nuclei with deep clefts, and undifferentiated cytoplasm containing isolated groups of polysomes. The outstanding morphologic feature of these cells was the development of highly convoluted infoldings of the plasma membrane which retained the labeled antigen. The term antigen-retaining reticular cell was used to identify this cell type. Villous extensions of immunoblasts were in close association with the antigen-retaining infoldings of these reticular cells. The relationship of the extracellular labeled antigen to the plasma-membrane infoldings of the antigen-retaining reticular cell remained the same until day 20. By 30 days there were no detectable grains present in germinal centers and the amount of plasma-membrane infolding of the reticular cells was decreased. Many virus-like particles were also found in germinal centers. These particles were located primarily in the membrane infoldings of antigen-retaining reticular cells and were also observed to be budding from typical immunoblasts.
Active metasomatism in the Cerro Prieto geothermal system, Baja California, Mexico: A telescoped low-pressure, low-temperature metamorphic facies series

In the Cerro Prieto geothermal field, carbonate-cemented, quartzofeldspathic sediments of the Colorado River delta are being actively metasomatized into calc-silicate metamorphic rocks by reaction with alkali chloride brines between 200/sup 0/ and 370/sup 0/C, low fluid and lithostatic pressures, and low oxygen fugacities. Petrologic investigations of drill cores and cutting from over 50 wells in this field identified a prograde series of calc-silicate mineral zones which include as index minerals: wairakite, epidote, prehnite, and clinopyroxene. Associated divariant mineral assemblages are indicative of a very low pressure/temperature metamorphic facies series which encompasses the clay-carbonate, zeolite, greenschist, and amphibolite facies. This hydrothermal metamorphic facies series, which is becoming increasingly recognized in other active geothermal systems, is characterized by temperature-telescoped dehydration and decarbonation mineral equilibria. Its equivalent should now be sought in fossil hydrothermal systems.
Species transport dynamics for clinical pulmonary evaluation

Various chemical species having different physicochemical properties (e.g., solubility) can be used to characterize many aspects of the pulmonary system. These include (a) gas distribution (or ventilation) inhomogeneity, (b) effective alveolar-capillary transport, (c) pulmonary blood flow, (d) pulmonary tissue (and capillary) volume, and (e) ventilation-perfusion inhomogeneity. Experimentally, the quickest methods to obtain these characteristics are based on the dynamic response to composition changes of pulmonary system inputs. For each method, the underlying mathematical model must be appropriately developed from dynamic mass-balance equations. The problems associated with making inferences about the pulmonary system in the presence of significant ventilation inhomogeneity are addressed. Many alternative approaches are considered with a critical examination of their advantages and limitations.
Secretory IgA as a Measure of Resistance to Infectious Disease: Comments on Stone, Cox, Valdimarsdottir, and Neale

We examined recent assertions of Stone, Cox, Valdimarsdottir, and Neale regarding the use of S-IgA concentrations in whole saliva as a measure of mucosal immune competence. Our conclusions are markedly different from theirs. In this article, we report the results of a meta-analysis that reveals a significant relation between psychosocial variables and salivary S-IgA concentrations. Second, we note that an inverse relation between salivary flow and S-IgA would not preclude studying salivary S-IgA concentration. Third, we present a different perspective on the assertion of Stone et al that IgA proteases in whole saliva potentially lead to erroneous results from the radial immunodiffusion assay. Fourth, we report a meta-analysis suggesting a statistically significant relation between S-IgA salivary concentrations and the incidence of acute upper respiratory illnesses. We conclude that there is no empirical or logical reason to prefer the measurement of another aspect of immunity to total S-IgA concentration in whole saliva.
INTRAHEPATIC FOCAL BILE STASIS IN 45, X TURNER'S SYNDROME: NEW SYNDROME COMPLEX?

Two cases are presented of 45,X Turner's syndrome who also had liver disease characterized by hepatomegaly and intrahepatic focal bile stasis with plugging of bile canaliculi. In one case a diagnosis was made of “neonatal hepatitis”, and the infant had a rapid downhill course with death at 10 1/2 months. The other patient is alive at age 18 with chronic hepatomegaly. Liver biopsy in the infant showed portal fibrosis with round cell infiltration. Lobular bile ducts were decreased in number, and many bile canaliculi were plugged with bile. Parenchymal giant cells were seen. In the older child there was hepatic focal bile stasis with bile plugs. Many nuclei showed glycogen vacuolization. Both children had anomalies of the great vessels: the infant an A-V malformation at the bifurcation of the iliacs, and the older girl aortic stenosis and anomalous pulmonary venous return. The hepatic syndrome could be due to a mutant allele on the pairing segment of the X chromosome, thus requiring monosomy X for its expression. Alternate hypotheses are that the hepatic disease is due to a rare X-linked trait, with expression only in monosomy X or XY individuals, or that aneuploidy in general may predispose to the hepatic syndrome (cf. Alpert et al., N.E.J.Med. 280:16, 1969).
Mechanism of polysialic acid chain elongation in Escherichia coli K1

Understanding the mechanisms of polysialic acid synthesis in Escherichia coli K1 requires a molecular description of the polymerase complex. Since the number of potential models explaining polysialic acid assembly would be constrained if only one sialyltransferase were required for this process, the phenotypes of a sialyltransferase null mutation generated by transposon mutagenesis were investigated. The chromosomal insertion mutation was mapped by Southern hybridization analysis and by complementation with plasmid subclones, demonstrating that sialyltransferase is encoded by neuS, a gene implicated previously as coding for the polymerase (Vimr et al., 1989). As expected, if only one gene encoded sialyltransferase, the null mutant had undetectable polymerase activity when assayed with endogenous or exogenous acceptors, and accumulated sugar nucleotide precursors intracellularly. Nested deletion analysis of neuS ruled out polarity effects of transposon insertion mutation and provided more precise mapping of the sialyltransferase structural gene. Maxicell analysis of the nested deletion set implicated a 34,000 molecular weight polypeptide as the neuS gene product. These results, together with biochemical characterization of sialyltransferase reaction products in the wild type, indicated that CMP-sialic acid is the probable sialosyl donor for polysialic acid elongation and that chain growth is by sequential addition of monomeric units.
The Green Fluorescent Protein Gene Functions as a Reporter of Gene Expression in Phanerochaete chrysosporium

The white rot basidiomycete Phanerochaete chrysosporium has been the focus of numerous studies of the degradation of the plant cell wall polymer lignin (14, 19, 30) and various aromatic pollutants (10, 22, 42, 43). Under ligninolytic conditions, this fungus secretes two families of peroxidases, lignin peroxidase (LiP) and manganese peroxidase (MnP), along with an H2O2-generating system, which are the major components of its extracellular lignin-degrading system (16, 19, 21, 28, 30, 51). MnP is an H2O2-dependent, heme-containing glycoprotein with an Mr of ∼46,000 which oxidizes Mn(II) to Mn(III) (6, 21, 38, 40, 47, 48, 50); the latter acts as a diffusible mediator in the oxidation of lignin model compounds (6, 16, 50, 51). The production of the idiophasic proteins MnP and LiP is activated by the depletion of nutrient nitrogen in culture (13, 19, 33, 40, 49). In addition, production of the MnP protein is dependent on, and transcription of the mnp gene is activated by, the presence of Mn(II) in the culture medium (7, 8, 15, 19). Production of MnP is also activated by oxidative stress (32) and heat shock (9). The promoter regions of the P. chrysosporium mnp genes contain several putative cis-acting elements which may be responsible for regulation in response to these environmental factors (2, 13, 18, 19). To study the regulation of genes encoding lignin-degrading enzymes, a suitable gene reporter system is required. Previously, we developed a reporter system based on the orotidylate decarboxylase gene from Schizophyllum commune (17). While this reporter system is sufficient for reporting the regulation of mnp by Mn(II) and nutrient nitrogen levels, the assay is complicated and uses a radioactive substrate. Green fluorescent protein (GFP) from Aequorea victoria has several advantages as a gene reporter system, and the enhanced gfp gene (egfp) contains a G + C content of 59%, which is the same as that of the P. chrysosporium genome (11, 12, 41). Furthermore, GFP can be used for monitoring both gene transcription and protein localization (11). In this work, we report that the GFP system faithfully reports gene expression when it is driven by the glyceraldehyde-p-dehydrogenase (gpd) or the mnp gene promoter from P. chrysosporium; however, efficient expression is observed only when an intron is inserted within the egfp gene.
Network-based regulatory pathways analysis

Motivation: A useful approach to unraveling and understanding complex biological networks is to decompose networks into basic functional and structural units. Recent application of convex analysis to metabolic networks leads to the development of network-based metabolic pathway analysis and the decomposition of metabolic networks into metabolic extreme pathways that are true functional units of metabolic systems. Metabolic extreme pathways are derived from limited knowledge of the metabolic networks, but provide an integrated predictive description of metabolic networks. It is important to extend the concept of network-based metabolic pathways to genetic networks and develop mathematical procedures for network-based regulatory pathway analysis. Results: We have established Kirchhoff's first law in genetic networks and introduced a concept of gene flows using matrix decomposition method. The Kirchhoff's first law provides the theoretical foundations for mathematical framework for development defining network-based regulatory pathways, and applying convex analysis in decomposing the genetic networks into regulatory extreme pathways. We presented a new approach to characterize the extreme pathway and developed a new algorithm for identifying a set of extreme pathways. Convex analysis and extreme pathway structure provide a unified framework for functional and structural analysis of metabolic and genetic networks, which will increase our ability to analyze, interpret and predict the function of metabolic and genetic networks. The proposed models for network-based regulatory pathway analysis have been applied to apoptosis regulatory network.
Rate constants for the reaction of OH radicals with a series of alkanes and alkenes at 299 ± 2 K

Using methyl nitrite photolysis in air as a source of hydroxyl radicals, relative rate constants for the reaction of OH radicals with a series of alkanes and alkenes have been determined at 299 ± 2 K. The rate constant ratios obtained are: relative to n-hexane = 1.00, neopentane 0.135 ± 0.007, n-butane 0.453 ± 0.007, cyclohexane 1.32 ± 0.04; relative to cyclohexane = 1.00, n-butane 0.341 ± 0.002, cyclopentane 0.704 ± 0.007, 2,3-dimethylbutane 0.827 ± 0.004, ethene 1.12 ± 0.05; relative to propene = 1.00, 2-methyl-2-butene 3.43 ± 0.13, isoprene 3.81 ± 0.17, 2,3-dimethyl-2-butene 4.28 ± 0.21. These relative rate constants are placed on an absolute basis using previous absolute rate constant data and are compared and discussed with literature data.
Peel Test Comparison

Three standardized peel test variations; unrestrained, 90 o restrained and 180 o restrained, for testing the integrity of edge sealed flexible pouches are compared in this article. A total of 30 samples of identically sealed pouches were tested for each method using standards set forth in ASTM F88/F88M-09. The three methods yielded consistent differences ranging from 40% between the 90 o restrained and unrestrained methods to 190% between the 90 o restrained and 180 o unrestrained methods.
Osteoporosis in anorexia nervosa

Anorexia nervosa is a condition associated with reduced bone mass and increased bone fragility, for which there is no known effective treatment. Anorexia nervosa usually has its onset during adolescence, the critical time when peak bone mass is accrued. Low bone mass is caused by reduced bone formation, as well as accelerated bone resorption. The etiology is multifactorial and includes poor nutrition, low bodyweight, sex hormone deficiency and hypercortisolism. Weight gain and resumption of menses is accompanied by some improvement in bone mass, but may not restore it to normal levels. Oral estrogen-replacement therapy is not effective in increasing bone mass in this disorder. The bisphosphonates, used in conjunction with nutritional rehabilitation and weight gain, have shown promise, but concerns about safety have limited their use. The aim of this article is to highlight recent recommendations regarding the assessment of fracture risk in children and adolescents, summarize the evidence for low bone mass and increased fracture risk in anorexia nervosa, and discuss approaches to the management of low bone mass in this disorder.
Kinematics of a Split-Equator Symmetrically Actuated Double Pointing System Used in a Robotic Wrist

This paper provides an overview of the embodiment of and explores in detail the finite kinematics of a spherical, split-equator robotic wrist joint. The joint physically consists of a symmetrically actuated, redundant spherical linkage, or double pointing system, for the pointing action of the joint and is accompanied by a third roll component of motion, thus completing the three degrees of freedom for the wrist joint. Kinematically, the wrist possesses a maximized dexterous workspace wherein the only singularity or “lock up” configuration occurs when the joint points back upon itself and would place the end effector inside of the forearm, a physically unreachable position.
Last-Recorded P2Y12 Reaction Units Value Is Strongly Associated with Thromboembolic and Hemorrhagic Complications Occurring Up to 6 Months after Treatment in Patients with Cerebral Aneurysms Treated with the Pipeline Embolization Device

BACKGROUND AND PURPOSE: A recent study identified a preprocedural P2Y12 reaction units value of 240 as a strong independent predictor of perioperative thromboembolic and hemorrhagic complications after treatment of cerebral aneurysms with the Pipeline Embolization Device. This study aimed to determine whether a last-recorded P2Y12 reaction units value of 240 predicts thromboembolic and hemorrhagic complications up to 6 months after treatment of cerebral aneurysms with the Pipeline Embolization Device in the same patient cohort. MATERIALS AND METHODS: We recorded patient and aneurysm characteristics, P2Y12 receptor antagonist administered, P2Y12 reaction units value with VerifyNow, procedural variables, and thromboembolic and hemorrhagic complications up to 6 months after Pipeline Embolization Device procedures at our institution during an 8-month period. Complications causing a permanent disabling neurologic deficit or death were considered major. Multivariate regression analysis was performed to identify independent predictors of thromboembolic and hemorrhagic complications. RESULTS: Forty-four patients underwent 48 Pipeline Embolization Device procedures at our institution during the study period. There were 11 thromboembolic and hemorrhagic complications up to 6 months after treatment in our cohort (22.9%), 5 of which were major (10.4%). A last-recorded P2Y12 reaction units value of 240 was the only independent predictor of all (P = .002) and major (P = .03) thromboembolic and hemorrhagic complications in our cohort. Most patients (71%) required, on average, 2 adjustments to the dose or type of P2Y12 receptor antagonist to remain within the 60–240 target P2Y12 reaction units range. CONCLUSIONS: In our cohort, a last-recorded P2Y12 reaction units value of 240 was the only independent predictor of all and major thromboembolic and hemorrhagic complications up to 6 months after Pipeline Embolization Device procedures.
Acoustic mode coupling in range dependent shallow water

This paper illustrates a matrix relationship between pressure fields at two ranges separated by an unknown medium. Once the matrix relationship is known, it can be used for acoustic calibration. A description of how to solve for the matrix is given and then the matrix is used to visualize mode coupling for several examples of varying ocean environments. >