cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure and stability of designed TPR protein superhelices: unusual crystal packing and implications for natural TPR proteins.

The structure and stability of repeat proteins has been little studied in comparison to the properties of the more familiar globular proteins. Here, the structure and stability of designed tetratricopeptide-repeat (TPR) proteins is described. The TPR is a 34-amino-acid motif which adopts a helix–turn–helix structure and occurs as tandem repeats. The design of a consensus TPR motif (CTPR) has previously been described. Here, the crystal structures and stabilities of proteins that contain eight or 20 identical tandem repeats of the CTPR motif (CTPR8 and CTPR20) are presented. Both CTPR8 and CTPR20 adopt a superhelical overall structure. The structures of the different-length CTPR proteins are compared with each other and with the structures of natural TPR domains. Also, the unusual and perhaps unique crystal-packing interactions resulting in pseudo-infinite crystalline superhelices observed in the different crystal forms of CTPR8 and CTPR20 are discussed. Finally, it is shown that the thermodynamic behavior of CTPR8 and CTPR20 can be predicted from the behavior of other TPRs in this series using an Ising model-based analysis. The designed protein series CTPR2–CTPR20 covers the natural size repertoire of TPR domains and as such is an excellent model system for natural TPR proteins.
Analysis of Monograph Obsolescence at Two Levels of an Interlibrary Loan Network.

Abstract Requests for monographs generated within an interlibrary loan network are analyzed for half-life statistics. It is suggested that demand represents use of the literature more completely than satisfied requests or circulation statistics. Demand in this study is characterized as either regional demand or statewide demand and is related to the level of the network where final processing of the request occurs. A negative exponential distribution is found to adequately characterize both levels of demand as a function of publication date for four subject categories. Corrected demand data is obtained by removing the growth rate of most of the available literature represented by American book publisher output. Based on over 10,000 interlibrary loan requests, negative exponential distributions describe the raw data as well as the corrected data. A shorter half-life was found for regional library demand (10.47 yr) than that found for statewide library demand (15.75 yr). Applying the correction factor to reflect the growth rate of the available literature tends to increase the half-life when compared to the raw data, and changes the ordering of subject classes with respect to ascending half-lives.
Refining the high-dose streptozotocin-induced diabetic non-human primate model: an evaluation of risk factors and outcomes:

In preparation for islet transplantation, diabetes was induced using streptozotocin (STZ) in non-human primates ranging from juveniles to adults with diverse body types: we studied the process with respect to the diabetic state and emergence of adverse events (AEs) and their severity, and identified risk factors for clinical and laboratory AEs. Pharmaceutical-grade STZ was given based on body surface area (BSA) (1050–1250 mg/m2, equivalent to 80–108 mg/kg) or on body weight (BW) (100 mg/kg) to 54 cynomolgus and 24 rhesus macaques. AEs were related to risk factors, i.e. obesity parameters, BW and BSA, age and STZ dose in mg/m2. Clinical AEs during the first days after infusion prompted euthanasia of three animals. Except for those three animals, diabetes was successfully induced as shown by circulating C-peptide levels, the intravenous glucose tolerance test and/or arginine stimulation test. C-peptide after infusion weakly correlated (P = 0.048) with STZ dose in mg/m2. Grade ≥3 nephrotoxicity or hepatotoxi...
Television news without pictures

(1987). Television news without pictures? Critical Studies in Mass Communication: Vol. 4, No. 1, pp. 74-78.
Fiber bed reactor design for animal cell culture

A design is presented in which cells are immobilized within a bed of glass fibers and are fed by continuous perfusion of liquid medium. The advantages of the design are first supported by a consideration of previously published data and theoretical relationships developed for fibrous beds. Next, experimental results based on this design are presented. Finally, unexpected productivity increases that appear to be unique to the fiber bed design are discussed
Adherence to physical activity guidelines in mid-pregnancy does not reduce sedentary time: an observational study.

Physical activity (PA) interventions designed to prevent prenatal complications have focused on increasing moderate PA yielding conflicting results. Minimal attention has focused on the evaluation of sleep, sedentary behavior (SB), light activity or total daily PA during pregnancy. The purpose of this prospective, longitudinal study was to 1) objectively quantify and compare habitual PA and SB during the 2nd and 3rd trimester; and 2) evaluate differences in activity patterns for women meeting prenatal PA guidelines versus those that did not. Forty-six participants wore 2 PA monitors (SenseWear® Mini and activPAL™) during week 18 and week 35 of pregnancy. We compared differences in sleep duration, postural allocation, daily steps, and PA between the 2nd and 3rd trimester and for women who met and did not meet PA guidelines. During the 2nd trimester, 30% of the women’s day (24-hours) was total sleep; 52% SB; 13% light; 3% moderate; and 0% vigorous PA. Light (P = 0.05), vigorous (P = 0.02), and moderate-vigorous PA (MET-minutes; P = 0.02), decreased with a trend in increased SB (P = 0.07). Activity of other intensities and sleep duration did not significantly change. Only 39% and 37% of participants slept between 7–9 hours/night at week 18 and 35, respectively. Forty-six percent (n = 21) and 28% (n = 13) of participants met prenatal PA guidelines during the 2nd and 3rd trimester, respectively. At week 18, no differences in total sleep, SB, or light PA existed for women who met PA guidelines versus those who did not; total PA was significantly greater for women who met guidelines. At week 35, women that met PA guidelines had significantly less SB (P < 0.005) than women who did not. This study demonstrates that pregnant women spend the majority of their day in SB. Significant reductions in total activity across pregnancy may be attributed, in part to shifts in light PA and increased SB. Based on the lifestyle of our sample, regardless of meeting PA guidelines in mid-pregnancy, no significant difference exists in time spent in SB, however meeting PA recommendations in late pregnancy may reduce SB. Future interventions should target reducing SB by increasing light and moderate PA beyond volitional exercise.
On the Yagita invariant of mapping class groups

Let Γ denote a group of finite virtual cohomological dimension and p a prime. If the cohomology ring H∗(Γ;Fp) has Krull dimension one, the p-period of Γ is defined; it measures the periodicity of H∗(Γ;Fp) in degrees above the virtual cohomological dimension of Γ. The Yagita invariant p(Γ) of Γ is a natural generalization of the p-period to groups with H∗(Γ;Fp) of Krull dimension larger than one. We compute the Yagita invariant p(Γg) for the mapping class group Γg with respect to an arbitrary odd regular prime p.
Synthesis of the isomeric monomethyl derivatives of the novel naphtho[2′,1′:4,5]thieno[2,3‐c]quinoline ring system

The synthesis of the novel naphtho[2′,1′:4,5]thieno[2,3-c]quinoline (11) ring system and four of the isomeric monomethyl derivatives is described.
Minimum nutritional requirements for cellular growth and extracellular slime polysaccharide production by the human dental plaque bacterial mutant Actinomyces viscosus T14Av

The requirements were examined in chemically-defined media. Magnesium sulphate, potassium phosphate and adenine were essential for cellular growth and sodium bicarbonate and inositol further stimulated growth. The addition of sodium phosphate to this medium stimulated both cellular growth and slime production. In contrast, ammonium sulphate inhibited slime production. Biotin and thiamine stimulated cellular growth and nicotinic acid was essential for slime production. Glutamine, alanine and cystine were essential for cellular growth. A minimal medium which supported both good cellular growth and slime production for strain T14Av contained adenine, sodium bicarbonate, MgSO4, inositol, glucose, KH2PO4, Na2HPO4, biotin, thiamine, nicotinic acid, arginine, glutamine, alanine and cystine.
Modulation of erythrocyte arginase activity in sickle cell disease patients during hydroxyurea therapy

An elevated erythrocyte arginase activity with a corresponding decrease in nitric oxide (NO) level has been implicated in the pathophysiology of sickle cell disease (SCD). Recent studies have shown that hydroxyurea (HU) increases the production of NO, which increases the soluble guanylate cyclase activity and fetal haemoglobin (HbF) synthesis. To study the effects of HU on the arginase and nitric oxide synthase (NOS) activities in SCD patients, we compared levels of arginase activity and NO metabolites in red blood cells and plasma, respectively, from 23 patients with SCD (HbSS) receiving HU therapy, with those of 12 SCD patients not receiving HU treatment. Patients on HU therapy showed significantly lower arginase activity than that of HbSS patients not on HU therapy (1.36+/-0.2 U/10(8) cells vs. 3.31+/-0.29 U/10(8) cells). NOS activity was higher in patients on HU therapy than in untreated patients (0.72+/-0.4 nmol/ml/min vs. 0.35+/-0.15 nmol/ml/min, P<0.05). Among the HU-treated patients, the decreased level of arginase activity correlated (r=0.71) with HbF level as well as the mean corpuscular haemoglobin content. These data suggest that one of the beneficial effects of HU in vivo may involve the regulation of arginase activity and a concomitant induction of NOS activity, which may lead to an increased production of NO. The outcome of this study may lead to the development of improved NO-based treatments for SCD.
Approximate life-cycle assessment of product concepts using learning systems

Thesis (Ph. D. in Environmental Systems Design)--Massachusetts Institute of Technology, Engineering Systems Division, Technology, Management, and Policy Program, 2002.
Intercomparison of volatile organic carbon measurement techniques and data at la porte during the TexAQS2000 Air Quality Study

The Texas Air Quality Study 2000 (TexAQS2000) investigated the photochemical production of ozone and the chemistry of related precursors and reaction products in the vicinity of Houston, TX. The colocation of four instruments for the measurement of volatile organic carbon compounds (VOCs) allowed a unique opportunity for the intercomparison of the different in-situ measuring techniques. The instruments included three gas chromatographs, each with a different type of detector, and a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS) with each system designed to measure a different suite of VOCs. Correlation plots and correlation statistics are presented for species measured by more than one of these instruments. The GC instruments were all in agreement to within 10−20% (slope) with coefficients of variation (r 2) of ≥0.85. The PTR-MS agreement with other instruments was more dependent on species with some very good agreements (r2 values of ∼0.95 for some aromatics), but isoprene, acetaldehyde and propene ...
Hemodynamic Effects of Ouabain in Patients with Mitral Stenosis and Sinus Rhythm

Abstract Eight patients with pure mitral stenosis in normal sinus rhythm were studied before and after intravenous administration of 0.5 to 0.7 milligrams of ouabain, by means of simultaneous measurements of cardiac output, oxygen consumption and pressures in the right atrium, pulmonary artery, left atrium, left ventricle and brachial artery. There were no significant changes in heart rate, systemic arterial or right atrial pressure following ouabain. Stroke index increased in all but 1 patient, from 31.4 to 37.5 ml./beat/ M. 2 ( p 2 and by 31 per cent from 40.7 gm.M./beat/M. 2 ( p p −5 ( p It is concluded that ouabain exerted a positive inotropic effect upon both the overloaded right and the normal left ventricle and had a small but definite pulmonary vasoconstrictor effect.
The Influence of Random Filament Packing on the Transverse Stiffness of Unidirectional Composites

Existing micromechanics analyses for the prediction of composite material properties, which are based upon the assumption of various idealized regular filament packings, indicate the significant in...
Current status of electrophosphorescent device stability

Abstract Operational stabilities of high-efficiency green and red electrophosphorescent bottom-emission devices with various emitting dopants have been studied. Operational lifetimes of 10,000 h or more, operated at an initial brightness of 600 and 300 cd/m2 for green and red, respectively, are reported. Operational stabilities of top-emission electrophosphorescent devices and electrophosphorescent devices built on barrier-coated plastic substrates have also been studied and show lifetimes >5000 and >2000 h, respectively, under display level brightness conditions.
True bandlimited diffusers

We have recently developed design and fabrication techniques that provide refractive diffusers with true bandlimited performance. We discuss design principles, comparison with alternate diffuser technologies, fabrication, testing, and some applications of bandlimited diffusers.
Sunlight, hormone replacement status and colorectal cancer risk in postmenopausal women.

A reanalysis of the Women's Health Initiative (WHI) randomized clinical trial found a significant interaction between supplementation with vitamin D/calcium and estrogen therapy and the risk of colorectal cancer risk, with reduced risks from supplementation limited to the placebo arms of the estrogen trials. To explore whether the vitamin D effects are modified by estrogen therapy, we report a largely cross-sectional, analysis of the association between sun exposure, which is an important vitamin D source, and colorectal cancer risk among postmenopausal women in the U.S. Radiologic Technologists study. Among 21,695 participants, there were a total of 108 cases. Sun exposure was based on time outdoors and on ambient ultraviolet radiation (UV) exposure based on residence linked to erythemal exposures derived from the Total Ozone Mapping Spectrometer database. Although there was no relationship between outdoor time or ambient UV measure and colorectal cancer risk in current hormone replacement therapy (HRT) users, in never/past HRT users, there was an inverse association with higher ambient UV exposure, RR for highest vs. lowest tertile = 0.40; 95% CI 017, 0.93; p for trend = 0.04. Non-significant lower risks were also associated with higher levels of outdoor time (≥3.5 hr/week) in never/past HRT users. The interaction between both indicators of sun exposure and HRT and CRC risk was not significant. These data, although exploratory, are consistent with evidence from the WHI suggesting a decrease in colorectal cancer risk may be associated with vitamin D exposure among postmenopausal women who are not taking HRT, but not among current HRT users.
Modulation of Resting State Functional Connectivity of the Brain by Naloxone Infusion

Recent work regarding the analysis of brain imaging data has focused on examining functional connectivity of the brain. In this paper, we developed and applied a novel framework to examine the modulation of functional connectivity networks during resting state or experimental stimuli. Hierarchical clustering within anatomically parcellated brain regions is used to cluster voxels into anatomically local, functionally homogenous groups. Parcellation allows for the assessment of connectivity at a region of interest level, rather than a voxel-specific level. The framework utilizes a mixed-effects model of the Fisher Z-transformed correlation between pairs of spatially distinct brain regions to assess the modulation of, or differences in, connectivity networks across multiple sessions or between groups of patients. A permutation test was employed to control family-wise type I error. We applied our method to evaluate the effects of a non-selective opioid receptor antagonist, naloxone, on resting state functional connectivity networks with multi-session multi-subject (n = 10) functional magnetic resonance imaging data. Naloxone induced a significant reduction in resting state connectivity between the right thalamus and the right parahippocampal gyrus when compared to saline solution.
Differences in Troponin C Dynamics Between Cardiac and Skeletal Muscle - A Molecular Dynamics Perspective

Troponin (Tn), part of the thin filament in cardiac as well as skeletal muscle, plays an important role in calcium signaling events in muscle contraction. It acts as a Ca2+-dependent switch, activating and deactivating the myofilament leading to contraction and relaxation of the muscle cell. An important mechanism in the regulation of contraction is the opening up of the Troponin C (TnC) hydrophobic patch to allow Troponin I (TnI) to bind. Two main structural differences are observed between cardiac TnC (cTnC) and skeletal TnC (sTnC): sTnC binds two calcium ions in its N-terminal regulatory domain, while cTnC only binds one calcium ion. The calcium binding site I in cTnC is inactive due to mutations. Additionally, the hydrophobic patch between helices A and B in the N-terminal regulatory domain is open in sTnC, while it is closed in cTnC. In previous work we performed microsecond molecular dynamics (MD) simulations of cTnC in different states of calcium binding to estimate the free energy difference for opening of the hydrophobic patch. Here we present long time-scale MD simulations of sTnC in its apo, one Ca2+-bound and two Ca2+-bound forms. We observe a 10,000-fold increased opening frequency in sTnC compared to cTnC. The dramatic difference is caused almost entirely by changes in the binding site I dynamics upon calcium binding. Investigations of sTnC mutations shown to prevent calcium binding to site I shed further light on the differences between the TnC isoforms. Additionally, Brownian dynamics simulations are used to investigate TnI association with TnC. Simulations of a full length troponin model elucidate the dynamical interplay between the TnC, TnI and TnT subunits.
Xanthine oxidase-catalyzed DNA binding of dihydrodiol derivatives of nitro-polycyclic aromatic hydrocarbons.

Summary Xanthine oxidase, a mammalian nitroreductase, catalyzed the covalent binding of a series of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) trans -dihydrodiols to DNA. Some of the trans -dihydrodiols bound to DNA to a greater extent than their parent nitro-PAHs; however, when the dihydrodiol moiety was peri to the nitro substituent low levels of binding were observed. These data illustrate that ring-oxidation and hydrolysis of nitro-PAHs to their trans -dihydrodiols followed by nitroreduction is a potential metabolic pathway leading to DNA adducts in mammals.
N-butyrate increases c-erb A oncogene expression in human colon fibroblasts

Abstract We investigated the effect of n-butyrate (2.5 mM) on expression of the c - erb A oncogene in human colon fibroblasts. Exposure of these cells to the compound for 48 hours resulted in an increased accumulation of approximately 2.0 kb RNA which hybridized to a v - erb A cDNA probe. Hybridization to a β-actin gene probe was unaffected by the treatment. This report is the first demonstration of a factor affecting expression of the c - erb A oncogene.
Evaluation of hypoxia-inducible factor-1α (HIF-1α) as an intrinsic marker of tumor hypoxia in U87 MG human glioblastoma: In vitro and xenograft studies

Abstract Purpose The transcription factor subunit hypoxia-inducible factor-1α (HIF-1α) is a key regulatory element of the hypoxic response of cells. High protein levels have been linked to poor prognosis in several tumor types, and HIF-1α has been suggested as a potential endogenous marker of tumor hypoxia and associated radioresistance. Methods and materials HIF-1α expression following in vitro hypoxia was measured in U87 MG glioblastoma cells by Western blot and flow cytometry. Cell suspensions from U87 MG xenograft tumors grown in SCID mice were assayed by flow cytometry for HIF-1α and for pimonidazole as a reference hypoxia marker. Results After 1 h, 6 h, and 18 h of in vitro hypoxia, a constant increase in HIF-1α protein levels with decreasing oxygen concentrations between 20% and in vitro hypoxia. In U87 MG xenograft tumors, flow-cytometric analysis of HIF-1α and pimonidazole showed a significant correlation of the two markers, but distinction of a HIF-1α-positive population was affected by a low dynamic range of the signal. As in published studies for HIF-1α and the hypoxic marker EF5, the colocalization of HIF-1α and pimonidazole in double-staining experiments was low. Conclusions While the in vitro data in U87 MG human glioblastoma cells support the use of HIF-1α as an endogenous hypoxia marker, comparison with the standard pimonidazole makes its application to clinical material appear questionable.
Molecular mechanisms related to parturition-induced stress urinary incontinence.

Background The molecular mechanisms underlying stress urinary incontinence (SUI) at the tissue level are poorly understood.
The rate of post-polypectomy bleeding for patients on uninterrupted clopidogrel therapy during elective colonoscopy is acceptably low

Background We do not routinely discontinue clopidogrel before colonoscopy because we have judged the cardiovascular risks of that practice to exceed the risks of post-polypectomy bleeding (PPB).
Changes in rainwater composition in Wilmington, NC during tropical storm Ernesto

Abstract Tropical weather events can contribute large wet depositional fluxes of biogeochemically important rainwater constituents over relatively short time periods. One composite sample during these events does not capture the dynamic nature of rainwater composition and can lead to misinterpretation of the impact of tropical events on local aquatic systems. Eight sequential samples were collected at 2–3 h intervals in Wilmington, NC during the duration of tropical storm Ernesto to examine a suite of rainwater constituents influenced by gas phase, aerosol, or mixed sources in the atmosphere. Real time wind speed and air mass back trajectories were used to examine the progression of the storm. Hydrogen peroxide and nitrate displayed washout trends during the storm. Dissolved organic carbon (DOC), hydrogen ion (H+), and total mercury (HgT) displayed washout at the beginning of the storm but toward the end of the storm concentrations increased, which corresponded to a shift in air masses from marine to terrestrial, increased ground air mass influence, and increased wind speeds. Integrated fluorescence, a measure of the chromophoric properties of the DOC, was highest at the beginning of the storm and than decreased but unlike DOC, the fluorescence did not increase at the end of the storm, indicating a change in the DOC source and composition during the storm. Chloride and sulfate, which are strongly influenced by seasalt aerosols, increased with increasing wind speeds. Factors such as wind speed, storm trajectory, and rainwater volume influenced rainwater constituent concentrations; the relative importance of these factors was a function of the sources of these rainwater constituents in rainwater.
Molecular-photoelectron angular distributions as a probe of dynamic symmetry breaking

Molecular-photoelectron angular distributions are shown to depend qualitatively on symmetry-breaking hole localization during inner-shell photoionization. This is illustrated by comparing localized and delocalized calculations of the asymmetry parameter $\ensuremath{\beta}(\ensuremath{\epsilon})$ for $K$-shell photoionization of ${\mathrm{N}}_{2}$ in the vicinity of the $f$-type shape resonance at approximately 10 eV above threshold. Comparison with the isoelectronic CO shows that the $K$-shell $\ensuremath{\beta}(\ensuremath{\epsilon})$ for ${\mathrm{N}}_{2}$, in the localized treatment, resembles that for the $K$ shell of oxygen rather than carbon in CO.
Rheological characterization of mammalian lung mucus

Mammalian lung mucus is a complex fluid that demonstrates non-linear viscoelastic responses, strain-stiffening at low and strain-softening at large strain values, as measured using large amplitude oscillatory shear (LAOS) experiments. The mechanical properties of lung mucus reported here can be linked to high-strain rate physiological processes, such as coughing, and can guide drug delivery development.
Stress in residency: Proposals for solution

Current problems leading to excessive stress in residency are presented and are compared with those of a generation ago. Solutions are proposed that can be summarized as follows: (1) commitment by the program director and chairman to resolving stress in residency and (2) flexibility by the American Board of Obstetrics and Gynecology and the Residency Review Committee. A general discussion is presented.
Evaluation of a modified model for deep bed filtration

Abstract The status of fundamental models of the performance of deep bed filters is reviewed and a modified model for monodisperse suspensions is presented. Particle removal is described by a modified version of the Vigneswaran and Tulachan model for the complete cycle of transient filter performance. A modification of the O'Melia and Ali approach and two linear approaches for headloss modeling are also described. The sensitivity of model predictions to variations in parameter values is presented. A comparison with experimental results for ripening and steady state conditions shows that particle removal can be described well while the observed linear (with time) headloss results cannot be described by modifications of the O'Melia and Ali approach. A surface area based linear headloss model appears to capture the effects of suspended particle size on headloss development while effects of coagulant type must be described by changes in model parameter values.
IgG anti-laminin-332 autoantibodies are present in a subset of patients with mucous membrane, but not bullous, pemphigoid.

Background Antiepiligrin cicatricial pemphigoid is a mucosal-predominant subepidermal blistering disease associated with an increased relative risk of cancer. In contrast to prior reports showing that anti-laminin (L)-332 autoantibodies are a reliable marker for patients with antiepiligrin cicatricial pemphigoid, a recent report suggested that as many as 40% of patients with bullous pemphigoid (BP) have IgG reactive with this laminin isoform. Objective We sought to determine whether patients with BP possess circulating IgG anti-L-332 autoantibodies. Methods Sera from 100 adults with BP were analyzed by indirect immunofluorescence testing of intact skin, immunoblot studies of human keratinocyte (HK) extracts, and a new L-332 enzyme-linked immunosorbent assay. Sera showing reactivity suggestive of anti-L-332 autoantibodies in these assays were further analyzed in immunoblot studies of HK extracellular matrix and immunoprecipitation studies of biosynthetically radiolabeled HK extracts. Results IgG from all patients with BP bound intact epidermal basement membrane by indirect immunofluorescence microscopy and immunoblotted bullous pemphigoid antigen-1, -2, or both in HK extracts. None of these sera immunoblotted L-332 in HK extracts, although 13 did score above the cut point of a new IgG 4 L-332 enzyme-linked immunosorbent assay (sensitivity = 0.91, specificity=0.98, Youden index=0.89). Further analysis of sera from these 13 patients found: (1) all had IgG that bound the epidermal side of 1 mol/L NaCl split skin by indirect immunofluorescence microscopy; (2) none immunoblotted L-332 purified from HK extracellular matrix; and (3) none immunoprecipitated L-332 from biosynthetically radiolabeled HK extracts. Limitations The basis of false-positive enzyme-linked immunosorbent assay determinations for anti-L-332 IgG among patients with BP is unknown. Conclusion Anti-L-332 autoantibodies remain a reliable marker for patients with antiepiligrin cicatricial pemphigoid.
In vitro synthesis of human immunodeficiency virus-specific antibodies in peripheral blood lymphocytes of infants

Abstract An assay system was developed for the analysis of antibodies secreted in vitro against human immunodeficiency virus (HIV) by cultured peripheral blood lymphocytes of HIV-infected individuals. Cultures of peripheral blood lymphocytes were established with medium alone or with medium containing Epstein-Barr virus (EBV) or pokeweed mitogen. HIV antibodies were determined by an ELISA performed with commercial kits in which a whole virus extract served as antigen. Optimal antibody secretion was detected in 7-day peripheral blood lymphocyte cultures to which EBV had been added to provide polyclonal B-cell activation. Pokeweed mitogen-induced antibody secretion and spontaneous antibody secretion were less consistent. With EBV as a stimulus, the sensitivity and specificity of this assay for determining HIV infection status were each 100% in adults. When the assay was applied to infants and children, 23 of 24 symptomatic HIV-seropositive children (class P-2) and 11 of 33 asymptomatic seropositive infants aged less than or equal to 15 months (class P-0) tested positive for EBV-induced antibody secretion. Six of the 11 P-0 patients who tested positive have progressed to develop symptomatic disease, while the remainder are still seropositive at ages 2-15 months. Of the infants who were negative in this assay, all have remained asymptomatic. Treatment with 3'-azido-3'-deoxythymidine in infected adults and children has resulted in transient suppression of the in vitro antibody response in some instances. Thus EBV-induced synthesis of HIV-specific antibodies in vitro is a sensitive and specific indicator of HIV infection and is of help in determining infection status of asymptomatic seropositive infants who are classified as having "indeterminate" infection.
Capture and display for live immersive 3D entertainment

We describe methods, accomplishments, and direction in a laboratory-corporate collaborative project over this past year and a half. With the goal of taking new immersive technologies to a growing customer base through in-situ demonstrations and experiments, we are combining novel capture and display capabilities in delivering life-sized immersive 3D entertainment experiences. We describe the adaptations and innovations needed in delivering immersive life sized 3D to a large audience.
Congenital oligonephropathy and the etiology of adult hypertension and progressive renal injury

Based on the associations reviewed in this report, we have hypothesized that retardation of renal development as occurs in individuals of low birth weight gives rise to increased postnatal risks for systemic and glomerular hypertension as well as enhanced risk of expression of renal disease. This hypothesis draws on observations suggesting (1) a direct relationship between birth weight and nephron number, (2) an inverse relationship between birth weight and later-life hypertension, and (3) an inverse relationship between nephron number and blood pressure, irrespective of whether nephron number is reduced congenitally or in postnatal life (as from partial renal ablation or acquired renal disease). Additional clinical and epidemiologic studies are needed to assess these initial impressions.
Short-Term Probabilistic Forecasts of Ceiling and Visibility Utilizing High-Density Surface Weather Observations

Abstract An automated statistical system that utilizes regional high-density surface observations to forecast low ceiling and visibility events in the upper Midwest is presented. The system is based solely upon surface observations as predictors, featuring forecast lead times of 1, 3, and 6 h. A test of the forecast system on a 5-yr independent sample of events shows that for a 1-h lead time, an additional 2%–4% reduction in the mean squared error (MSE) is obtained by the high-density forecasting system compared to that for a system utilizing only the standard synoptic observations. Meanwhile, tests on a 3-h lead time reveal an additional 0%–1.5% reduction in MSE by the high-density system over the synoptic system. Little improvement is gained by the high-density system at a 6-h lead time. The results indicate that current observations-based forecasting techniques can be improved simply by utilizing a higher density of surface weather observations. With this enhanced guidance, it is likely that decisions ...
Partial self-fertilization and inbreeding depression in two populations of Mimulus guttatus

Partial self-fertilization and inbreeding depression in two populations of Mimulus guttatus
Loss of glucocorticoid‐dependent growth inhibition in transformed mouse lung cells

Transformed A5 mouse lung cells were examined for mechanisms that may explain their loss of glucocorticoid-induced growth inhibition. These cells were compared to nontransformed C10 mouse lung cells, which retain this response. Southern blot analysis revealed no major differences in the amount or pattern of restriction fragments for the glucocorticoid receptor (GR) gene between the responsive and nonresponsive cells. Northern blot analysis demonstrated that both cell lines expressed GR mRNA at similar levels and that these mRNAs had similar relative stabilities. The mRNA from both cell lines was used for reverse transcription-polymerase chain reaction amplification and direct sequencing with primers for different regions of the GR cDNA. A conservative mutation previously shown not to affect receptor function was detected within the DNA-binding domain region of the GR from both cell lines. Because of the ability of the transcription factors for activator protein-1 to antagonize GR function, c-jun and c-fos mRNA levels were examined. A5 cells were found to have higher levels of c-jun mRNA than C10 cells both during active cell growth and after serum starvation. Stable transfection of the nonresponsive A5 cells with a rat GR expression vector (A5GR7) resulted in strong glucocorticoid-induced growth inhibition, demonstrating that these cells retain the ability to be growth inhibited by these steroids. The A5GR7 transfectants also had higher mouse mammary tumor virus (MMTV)-chloramphenicol acetyltransferase (CAT) activity than the parental A5 cells and lower levels of c-jun during active cell growth. Transient transfection of the C10 cells with c-jun expression vector strongly reduced glucocorticoid-inducible MMTV-CAT activity. These results suggest that the transformed A5 cells apparently contain functional GR but that the high level of c-jun mRNA expression (probably resulting from the activated Ki-ras allele in these cells) may antagonize their ability to respond to the growth-inhibitory signaling of glucocorticoids.
An ultrafast barcode reader using amplified dispersive Fourier transform

Dispersive Fourier transformation (FT) is a powerful technique in which the spectrum of a pulse is mapped into a time-domain waveform using chromatic dispersion. It replaces a diffraction grating and detector array with a dispersive fiber, single photodetector, and digitizer. This simplifies the system, and more importantly, enables fast real-time spectroscopy . Dispersive FT has also been used for optical coherence tomography. Here we propose and demonstrate a novel imaging method using dispersive FT for ultrafast displacement sensing and barcode reading. This method, which we refer to as chirped wavelength encoding and electronic time domain sampling (CWEETS), exposes a sample to a broadband pulsed probe beam which is spatially dispersed by a diffraction grating so that each separated wavelength of the probe beam is incident on a different part of the sample along a transverse line on the sample. The reflectivity profile of the sample is encoded into the spectrum of the reflected light from the sample. It is then subjected to dispersive FT using group-velocity dispersion to detect the reflectivity profile of the sample in the time domain. To overcome the loss of the dispersive element, we introduce Raman amplification in the same medium, resulting in greatly enhanced resolution.
Gli3 coordinates three-dimensional patterning and growth of the tectum and cerebellum by integrating Shh and Fgf8 signaling

The coordination of anterior-posterior (AP) and dorsal-ventral (DV) patterning of the mesencephalon (mes) and rhombomere 1 (r1) is instrumental for the development of three distinct brain structures: the tectum and cerebellum dorsally and the tegmentum ventrally. Patterning of the mes/r1 is primarily mediated by signaling molecules secreted from two organizers: sonic hedgehog (Shh) from the floor plate (DV) and Fgf8 from the isthmus (AP). Gli3, a zinc-finger transcription factor in the Shh signaling pathway, has been implicated in regulating Fgf8 expression and is therefore a potential candidate for coordinating the action of the two organizers. By inactivating mouse Gli3 at successive embryonic time points in vivo, we uncovered the extent and the underlying mechanism of Gli3 function in the mes/r1. We demonstrate that before E9.0, Gli3 is required for establishing a distinct posterior tectum, isthmus and cerebellum, but does not play a role in the development of the tegmentum. Between E9.0 and E11.0, Gli3 continues to be required for isthmus and cerebellum development, but primarily for defining the cerebellar foliation pattern. We show that Gli3 regulates patterning of the isthmus and cerebellar anlage by confining Fgf8 expression to the isthmus, and attenuates growth of dorsal r1 (before E11.0) and the dorsal mes and isthmus (beyond E11.0) through regulation of cell proliferation and viability. In conclusion, our results show that Gli3 is essential for the coordinated three-dimensional patterning and growth of the dorsal mes/r1.
Fluorescent optical tomography with large data sets

In recent years, optical tomography (OT) of highly scattering biological samples has increasingly relied on noncontact CCD-based imaging devices that can record extremely large data sets, with up to 10(9) independent measurements per sample. Reconstruction of such data sets requires fast algorithms. The latter have been developed and applied experimentally in our previous work to imaging of the intrinsic absorption coefficient of highly scattering media. However, it is widely recognized that the use of fluorescent contrast agents in OT has the potential to significantly enhance the technique. We show that the algorithms previously developed by us can be modified to reconstruct the concentration of fluorescent contrast agents.
Spin split-off band-based high operating temperature IR detectors in 3-5 Âµm and beyond

Overcoming the stringent cooling requirement for the operation of most of the infrared (IR) detectors is one of the major challenges towards capturing their full potential. Split-off (SO) transitions based detector exhibit encouraging results and gives hope to provide a novel alternative to the conventional IR detectors operating with cryogenic aid. Recently, a GaAs/AlGaAs SO detector operating up to 330 K in the 3-5 μm spectral region was developed. This paper presents various design modifications including graded barrier (in place of flat barrier), and double barrier resonant structure (in place of a single barrier) to improve the performance of these detectors. The graded barrier improves the detector performance by reducing the space charge buildup due to the trapping of charge carriers at the emitter-barrier interface; additionally, the model implementation on GaAs/AlGaAs based detectors also suggests that a barrier offset of 20 meV approximately doubles the responsivity. The implementation of a double barrier resonant structure increases the escape of holes from the SO to the light/heavy hole (LH/HH) bands by bringing the two bands into resonance and increases the response by a factor of ~ 85. The results from our ongoing efforts to extend the concept of SO mechanism based IR detection towards longer wavelength are also presented. This should be possible by exploiting SO absorption in alternative material systems such as phosphides and nitrides. The successful utilization of SO mechanism can result in the high operating temperature detectors operating in mid-IR and terahertz (THz) region.
Ganglionic nAChRs and high-affinity nicotinic binding sites are not equivalent

High-affinity (Kd approximately equal to 10 nM) binding sites for nicotine and acetylcholine (ACh) have recently been identified in vertebrate brain. It has been suggested that these sites are desensitized ganglionic (C6) nicotinic acetylcholine receptors (nAChRs). We have tested the pheochromocytoma cell line PC12, which is known to contain well-expressed C6 nAChRs, to determine if these nAChRs are associated with high-affinity [3H]ACh-binding sites. We found that the high-affinity nicotinic [3H]ACh-binding site is absent in PC12 cells. We also found that the concentration of nicotine or ACh necessary to desensitize carbamylcholine-stimulated Na+ flux was at least two orders of magnitude greater than the concentrations used in binding experiments. We conclude that high-affinity nicotinic binding sites are not equivalent to C6 ganglionic receptors.
Studies with 59Fe-labeled hemin on the control of polyribosome formation in rabbit reticulocytes

Abstract 1. 1. The incorporation of hemin (protohemin) labeled with 59Fe into hemoglobin of rabbit reticulocytes is characterized by a rapid uptake which is independent of concomitant protein synthesis, followed by a slower incorporation rate which is dependent on protein synthesis. The extent of incorporation of hemin into hemoglobin in the absence of protein synthesis may be considered an estimate of the free globin in the cell. 2. 2. The level of free globin in reticulocytes with polyribosomes disaggregated by iron deficiency is not significantly altered from that found in cells with a high proportion of polyribosomes. The results suggest that the polyribosome disaggregation due to heme deficiency does not result from feedback inhibition of chain initiation by free globin chains. 3. 3. When added to intact reticulocytes, labeled hemin becomes rapidly associated with the ribosome-polyribosome component. Puromycin, at a concentration causing removal of nascent chains from the polyribosomes, promotes some polyribosome disaggregation but has little effect on the level of associated hemin. Therefore, polyribosomes are not stabilized by the association of hemin with nascent peptide chains. 4. 4. Deuterohemin, labeled with 59Fe is not bound to the ribosome-polyribosome component after it promotes polyribosome regeneration in iron-deficient cells. Neither hemin or deuterohemin appear to bind to the native ribosomal subunits. 5. 5. The results suggest that binding of metalloporphyrins to the ribosome-polyribosome component is not essential for its mechanism of action in maintenance of polyribosome integrity, but that they may function by directly enhancing attachment of ribosomes to messenger RNA (mRNA). Hemin may be a cofactor for an initiation enzyme or it may act by combining with structural components of the cell which are dissociated from the polyribosomes upon lysis.
Estimation and tracking of time-varying channels in OFDM systems

We propose a method for channel estimation in orthogonal frequency division multiplexing (OFDM) systems. Unlike the conventional sample-spaced and sub-sample-spaced methods, which target the taps of an equivalent discrete-delay channel response, this method targets the physical propagation paths in a continuous-delay domain. Numerical results quantify its benefits over the conventional least-squares, orthogonal matching pursuit, and mixed-norm methods. Assuming that channel is slowly varying from one OFDM block to another, we also develop an adaptive algorithm for channel tracking. Performance is illustrated through simulation.
Review of the state-of-the-art measurements for and the phenomenon of anomalously low thermal conductivities of dielectric thin films

Over the past decade, researchers in the laser optics, semiconductor electronics, and solid- state physics fields have shown that thin films of dielectrics a few micrometers or less in thickness can have measured thermal conductivities values significantly lower than if in normal bulk form. The values can be lower by several orders of magnitude and often decrease with decreasing film thickness. These phenomena have been observed in thin films of various dielectrics deposited or grown by various methods on various substrates. Preliminary explanations for these observations have centered around atomic- or molecular-sized defects or distortions in conjunction with high thermal resistances at or near the interface between the thin film and the substrate. This work has also fostered the initial development and assessment of apparently viable techniques for making measurements of thermal conductivities of thin films in the direction normal to the interface. The state-of-the-art of this work is reviewed.
An arithmetic remark on entire periodic functions

For every positive number w , there exists an odd entire transcendental function . with rational integral coefficients a h such that f〈z+w〉 = f 〈 z 〉.
Crack propagation generated by a horizontally polarized shear wave

A plane horizontally-polarized shear wave propagates into an undisturbed brittle elastic material containing a void. This paper inquires into the conditions for initiation of crack propagation at an instantaneous velocity upon diffraction of the wave by the void. The investigation consists of two parts. In the first, the particle velocity and the shear stresses are determined for diffraction of a transient wave of arbitrary shape by a wedge-shaped void which produces a running crack at the instant the wave front strikes the tip of the wedge. In the second, the balance of rate-of-energy is employed to determine that shape of the incident pulse which is consistent with crack propagation at an instantaneous velocity. It is shown that near the wave front the incident displacement wave must be of the form of a square root of the general argument t−ax−by. For this particular type of incident wave, the instantaneous velocity of crack propagation is computed as a function of the angle of incidence, the “amplitude” of the incident wave, and of the material parameters.
Modeling of the microwave drying process of aqueous dielectrics

We propose a thermodynamic framework for describing the microwave drying process of aqueous dielectrics based on Maxwell-Lorentz field equations and mixture theory. Several issues are discussed such as the form of entropy equation; the constitutive relations for the macroscopic electric polarization vectors, Cauchy stresses, heat fluxes, internal momentum supplies, etc., for each component of the mixture: porous solid, water and gas in different regions; and the interfacial jump conditions between different regions in the mixture. A brief examination of the status of material frame indifference within the context of our framework is presented.
An analytical study towards the development of a standardized IM application

Abstract The technology of instant messaging (IM) currently permeates our various methods of communication. However, since the technology is incapable of providing consistent communication across all channels the users utilize instant messaging as a secondary form of communication. The problem of interoperability between vendors is discussed and proposed solutions examined. Specifically, the standards proposed through the Internet Engineering Task Force (IETF) are presented and evaluated as viable solutions to the problem of standardization. A determination of the requirements for a standard is developed and presented so as to recognize the important elements necessary to maintain and expand instant messaging. Finally, an examination of the future of IM application capable of interoperability is offered so as to describe how the technology might thrive given the proper foundation.