cssi/SciSciGPT-SciSciNet huggingface dataset:
Adaptive Reduced Complexity Multicarrier CDMA (MC‐CDMA) Structure for Downlink PCS

Conventional multiuser code division multiple access (CDMA) suffers from the well-known near-far problem. Both the conventional decorrelator and an adaptive separator termed bootstrap algorithm were used to mitigate this problem and obtain near-far resistant receivers. These approaches still require the knowledge of which users are active and their respective codes. Eliminating this requirement is advantageous for downlink communication as only the desired user is of interest. Furthermore, in a multipath environment the use of the RAKE receiver adds to the complexity. A transmission method called multicarrier CDMA (MC-CDMA) uses multiple narrowband subcarriers and, as a result, the channel is flat-fading at each subcarrier. In this paper, a receiver for downlink MC-CDMA is proposed that does not require the knowledge of which users are active. This is achieved by replacing the bank of matched filters of the full dimensional multiuser detector by 2 matched filters; one for the desired user and one representing all the interfering users combined in a specific way. Additionally, this significantly reduces the number of adaptively controlled weights. The performance of this system is analyzed and simulation results are obtained for the Rayleigh fading channel with and without correlation between the subcarriers.
Minireview: Estrogenic Protection of β-Cell Failure in Metabolic Diseases

The prevalence of diabetes is lower in premenopausal women, especially diabetic syndromes with insulin deficiency, suggesting that the female hormone 17β-estradiol protects pancreatic β-cell function. In classical rodent models of β-cell failure, 17β-estradiol at physiological concentrations protects pancreatic β-cells against lipotoxicity, oxidative stress, and apoptosis. In this review, we integrate evidence showing that estrogens and their receptors have direct effects on islet biology. The estrogen receptor (ER)-α, ERβ, and the G-protein coupled ER are present in β-cells and enhance islet survival. They also improve islet lipid homeostasis and insulin biosynthesis. We also discuss evidence that ERs modulate insulin sensitivity and energy homeostasis, which indirectly alter β-cell biology in diabetic and obese conditions.
Healing of exposed dental pulps under various pressure dressings

Abstract 1. 1. Healing of previously sound pulps under pressure dressings consisting of calcium hydroxide mixed with zinc oxide or barium sulfate was studied in twenty adult teeth. The postoperative period ranged from 5 days to 6 months. 2. 2. Subsequent to the operation, fifteen teeth were asymptomatic and five showed only slight discomfort of short duration. 3. 3. Histologically, results were considered successful in twenty pulps; failures were recorded in two cases.
Plasma deposition of hydrogenated amorphous silicon: Studies of the growth surface

This review focusses on the plasma-surface interactions and surface processes involved in a-Si: H thin film growth. We restrict our discussion of growth fluxes to a summary, and do not address plasma kinetics. In recent years, powerful in situ experiments have been carried out on the growing film surface, which reveal the adsorption, penetration, reaction, and elimination of precursor species, as well as the atomic-scale morphology and composition of the growth zone. Good data sets are available both for PACVD and reactive magnetron sputter deposition. These form an interesting comparison, since the former process is dominated by the hydrogen-rich radical SiH3 at low energy, and the latter by energetic atomic Si and H. We review the key experiments and conclusions, underlining those aspects which are well established and those which remain qualitative; and we discuss the transition from amorphous to fine-grained polycrystalline film growth at high hydrogen pressures in terms of the surface mechanisms. This field is now entering a scientific stage where a detailed theory of low-temperature, plasma-assisted growth can be developed.
Karyotypic differentiation in a spontaneous mouse B-cell leukemia

Abstract The karyotype of a spontaneous mouse B-cell leukemia passaged intravenously several times in succession into syngeneic recipients was determined. Peripheral lymphocytes from a control animal and from animals in passage 1 and 7 were stimulated by the mitogen lipopoly-saccharide, and studied by Giemsa banding methods. In passage 1, the cultured lymphocytes consisted of 4 clones, one with a normal karyotype (1 cell out of 32), and three with multiple chromosome changes. One clone, representing about 10% of all mitoses, had 39 chromosomes with monosomy for chromosomes 12 and 13, two reciprocal translocations, and a small marker chromosome. One of the translocations had occurred between chromosomes 4 and 15, the other between an X chromosome, and one chromosome No. 8. Another clone had 37 chromosomes (6% of all mitoses), and the remaining clones had 36 chromosomes (81% of all mitoses). These clones had the same chromosome changes as the clone with 39 chromosomes, three additional monosomies (6, 8, and 15), and three new translocations. In passage 7 the clone with 36 chromosomes represented about 30% of the cultured cells, while 70% of the cells had 35 chromosomes; the reduction in number was caused by a 17;19 translocation. The cultures from the control animals had a normal karyotype.
Marburg Virus Vaccines Based upon Alphavirus Replicons Protect Guinea Pigs and Nonhuman Primates

Marburg virus (MBGV), for which no vaccines or treatments currently exist, causes an acute hemorrhagic fever with a high mortality rate in humans. We previously showed that immunization with either killed MBGV or a glycoprotein (GP) subunit prevented lethal infection in guinea pigs. In the studies reported here, an RNA replicon, based upon Venezuelan equine encephalitis (VEE) virus, was used as a vaccine vector; the VEE structural genes were replaced by genes for MBGV GP, nucleoprotein (NP), VP40, VP35, VP30, or VP24. Guinea pigs were vaccinated with recombinant VEE replicons (packaged into VEE-like particles), inoculated with MBGV, and evaluated for viremia and survival. Results indicated that either GP or NP were protective antigens while VP35 afforded incomplete protection. As a more definitive test of vaccine efficacy, nonhuman primates (cynomolgus macaques) were inoculated with VEE replicons expressing MBGV GP and/or NP. Three monkeys received packaged control replicons (influenza HA); these died 9 or 10 days after challenge, with typical MBGV disease. MBGV NP afforded incomplete protection, sufficient to prevent death but not disease in two of three macaques. Three monkeys vaccinated with replicons which expressed MBGV GP, and three others vaccinated with both replicons that expressed GP or NP, remained aviremic and were completely protected from disease.
Full wave analysis of periodic wedge absorber

The performance of radar absorbing material (RAM) is analyzed numerically in low-to-mid frequency range. The dielectric properties of actual absorber were measured and used in the analysis. In the analysis, the so called, Volume-Surface Integral Equation (VSIE) is modified to handle the scattering not only for side incidence but also for forward incidence (i.e., along the wedges). This results in two coupled integral equations in terms of longitudinal electric and magnetic fields. By taking advantage of geometry periodicity, the integration interval is reduced from infinite to one period using Floquet mode expansion. These integral equations are then solved numerically using a point matching technique. The computer code is verified by computing reflection from a lossy slab backed by a perfect conductor and comparing the results to those obtained from exact solution. The scattered fields of infinitely periodic lossy wedges backed by a perfect conductor are computed for a number of cases and the results are...
Direct Interaction of a Ca2+-binding Loop of Synaptotagmin with Lipid Bilayers

Synaptotagmin 1 binds Ca2+ and membranes via its C2A-domain and plays an essential role in excitation-secretion coupling. In this study, we sought to identify Ca2+- and membrane-induced local conformational changes in the C2A-domain of synaptotagmin and to delineate the C2A-lipid binding interface. To address these questions native phenylalanine residues were replaced, at each face of the domain, with tryptophan reporters. Changes in tryptophanyl fluorescence indicated that Ca2+induced long range conformational changes throughout C2A, including regions distant from an established Ca2+-binding site. Addition of liposomes resulted in Ca2+-dependent increases in the fluorescence of tryptophans 193, 231, and 234. Only the tryptophan residues at positions 234 and 231, which lie within a Ca2+-binding loop of C2A, exhibited liposome-induced blue shifts in their emission spectra. Quenching experiments, using membrane-imbedded doxyl spin labels, revealed that tryptophan residues 231 and 234 penetrated lipid bilayers. These data delineate the lipid binding interface of C2A and provide the first evidence for adjacent Ca2+- and lipid-binding sites within a C2-domain. The penetration of C2A into membranes may function to bring components of the fusion machinery into contact with the lipid bilayer to initiate exocytosis.
A new species of Calohypsibius (Phylum Tardigrada, Eutardigrada) from Roan Mountain, Tennessee-North Carolina, U.S.A.

Abstract The ecological distributions of tardigrade species from six sites on Roan Mountain, Tennessee-North Carolina, were determined in a study begun by D.R. Nelson in 1971. Three new species of eutardigrades were discovered in Nelson's study, but remained undescribed. A follow-up to that study was initiated by K.L. McGlothlin in 1988 to determine the long-term stability of tardigrade populations at two of Nelson's original collection sites. Two of Nelson's three new eutardigrade species were rediscovered by McGlothlin, and one newPseudechiniscusspecies was found. The description of one of the eutardigrades,Hypsibius roanensis, was published previously. The remaining eutardigrade found during both studies, a new species ofCalohypsibius, is described here:Calohypsibius schusterisp. nov.
Report on the teichmüller metric.

Abstract Let Tg be the Teichmuller space of compact Riemann surfaces of genus g. Then Tg is the space of conformal structures on a fixed surface W modulo equivalence under conformal maps homotopic to the identity. The Teichmuller modular group [unk] is the group of all orientation preserving homeomorphisms of W onto itself modulo those which are homotopic to the identity. Each element of [unk] induces a biholomorphic map of Tg onto itself, and the present note outlines a proof of the converse statement: Every biholomorphic map of Tg onto itself is induced by an element of [unk]. It is first shown that every isometry of Tg with the Teichmuller metric arises from an element of [unk]. The Teichmuller metric is then shown to be the Kobayashi metric for Tg and hence invariant under biholomorphic maps.
Mask line monitor: process improvements and yield learning

With ever increasing linewidth challenges per technology changes, the mask manufacturing process becomes more and more difficult. The challenges can be separated into two categories: image size and defects. Mask inspection detects hard defects most likely caused somewhere in the mask manufacturing process. Defect partitioning highlights the hard defects sources. They range from pre-exposure mask blank handling to the cleanliness of the process tools. A test vehicle was designed to allow for mask manufacturing defect partitioning via a die-to-die inspection tool. The process changes implemented range from pre-write mask handling to tool modifications. The methodology used to determine the process induced defects and the yield gains by making the necessary process changes will be presented.
Atomic-resolution crystal structure of Borrelia burgdorferi outer surface protein A via surface engineering.

Outer surface protein A (OspA) from Borrelia burgdorferi has an unusual dumbbell-shaped structure in which two globular domains are connected with a “single-layer” β-sheet (SLB). The protein is highly soluble, and it has been recalcitrant to crystallization. Only OspA complexes with Fab fragments have been successfully crystallized. OspA contains a large number of Lys and Glu residues, and these “high entropy” residues may disfavor crystal packing because some of them would need to be immobilized in forming a crystal lattice. We rationally designed a total of 13 surface mutations in which Lys and Glu residues were replaced with Ala or Ser. We successfully crystallized the mutant OspA without a bound Fab fragment and extended structure analysis to a 1.15 A resolution. The new high-resolution structure revealed a unique backbone hydration pattern of the SLB segment in which water molecules fill the “weak spots” on both faces of the antiparallel β-sheet. These well-defined water molecules provide additional structural links between adjacent β-strands, and thus they may be important for maintaining the rigidity of the SLB that inherently lacks tight packing afforded by a hydrophobic core. The structure also revealed new information on the side-chain dynamics and on a solvent-accessible cavity in the core of the C-terminal globular domain. This work demonstrates the utility of extensive surface mutation in crystallizing recalcitrant proteins and dramatically improving the resolution of crystal structures, and provides new insights into the stabilization mechanism of OspA.
Implicit solvent simulations of peptide interactions with anionic lipid membranes

A recently developed implicit mem- brane model (IMM1) is supplemented with a Gouy- Chapman term describing counterion-screened elec- trostatic interactions of a solute with negatively charged membrane lipids. The new model is tested on peptides that bind to anionic membranes. Penta- lysine binds just outside the plane of negative charge, whereas Lys-Phe peptides insert their aromatic rings into the hydrophobic core. Melittin and magainin 2 bind more strongly to anionic than to neutral membranes and in both cases insert their hydrophobic residues into the hydrocarbon core. The third domain of Antennapedia homeodo- main (penetratin) binds as an -helix in the head- group region. Cardiotoxin II binds strongly to anionic membranes but marginally to neutral ones. In all cases, the location and configuration of the peptides are consistent with experimental data, and the effective energy changes upon binding compare favorably with experimental binding free energies. The model opens the way to exploring the effect of membrane charge on the location, conformation, and dynamics of a large variety of biologically active peptides on membranes. Proteins 2005;58:518 -527. © 2004 Wiley-Liss, Inc.
PRIMARY HYPOTHYROIDISM CAUSES DECREASED EXPRESSION OF THYROID TRANSCRIPTIONAL FACTOR-1 AND SURFACTANT PROTEIN-C IN FETAL MOUSE LUNG. † 2063

Thyroid hormones play an important role in mammalian fetal lung development. Delayed fetal lung ultrastructural maturation is observed in the Hyt/Hyt mouse which has primary hypothyroidism due to a point mutation(Pro-556-Leu) in the β subunit of the TSH receptor (Ped. Res.380-386,1994). Thyroid transcriptional factor 1 (T.T.F.-1) and surfactant protein C (SP-C) play an important role in fetal lung function and type II cell differentiation. The effect of primary hypothyroidism on the developmental expression of lung SP-C or TTF-1 has not been studied. Hypothyroid (Hyt/Hyt) mice, characterized by high serum TSH and low serum free T4 concentration, were made euthyroid by T3 supplementation. These mice were mated to produce hypothyroid (Hyt/hyt) pups. Balb-c mice served as euthyroid controls. Mice were killed on d 18 of pregnancy (term≈19d, vaginal plug=d 1). Immunostaining of fetal lung for SP-C was done using polyclonal antibody. The intensity of the immunoreactivity for SP-C was scored on a scale of 0 to 3 in 0.5 increments. Fetal lung gene expression for T.T.F.-1 and SP-C was determined by Northern analysis and densitometry. All data Mean ±SEM, * P<0.02 There was a linear relationship between the gene expression for T.T.F.-1 and SP-C in these mice (r=0.86). We conclude that primary hypothyroidism causes a delay in the gene expression for TTF-1 and SP-C in the fetal lung. Table
Isolation and characterization of a cDNA encoding NADP+-specific isocitrate dehydrogenase from soybean (Glycine max)

A cDNA that encodes an NADP-specific isocitrate dehydrogenase (IDH) was cloned from a soybean nodule cDNA library by complementation of an Escherichia coli mutant that lacked IDH. DNA sequence analysis showed that the 1583 bp soybean cDNA could encode a protein that shares 63.9% amino acid sequence identity with the Saccharomyces cerevisiae NADP-IDH and long sequences of identity to an IDH from pig. Southern blot analysis suggests that this gene corresponds to a gene family made up of no more than two loci. The IDH cDNA hybridized to a 1.7 kb soybean mRNA and the relative amount of this transcript in soybean leaves, nodules and roots was 1:3.4:7.7. In alfalfa, a 1.7 kb mRNA was also found but the ratios for the corresponding tissues were 1:7.4:7.7. IDH activity was detected in the complemented E. coli strain and the electrophoretic mobility of this activity in nondenaturing polyacrylamide gels was identical to that of an IDH in extracts from soybean cotyledons or nodule cytosol. NADP-IDH specific activity in the E. coli host strain varied with growth phase; the highest rates (ca. 180 nmol/min per mg protein) were observed in late-stationary-phase cells. The enzyme had a broad pH optimum of 8.0 to 9.5 and had an absolute metal cofactor requirement, preferring Mn2+ below pH 8.0 and Mg2+ above pH 8.0. The Km for isocitrate and NADP was 21 μM and 11 μM respectively with Mn2+ as cofactor and 13 μM and 12 μM with Mg2+ as cofactor.
Radiative width of the K∗+ (1430)

Abstract Using the Primakoff formalism, we have extracted the radiative decay width of the K ∗+ (1430) produced in coherent interactions of 200 GeV/ c K + mesons in nuclear targets. The width obtained is 240 ± 45 keV, a value reasonably consistent with quark-model predictions.
Structure-based dissociation of a type I polyketide synthase module.

Summary Individual modules of modular polyketide synthases (PKSs) such as 6-deoxyerythronolide B synthase (DEBS) consist of conserved, covalently linked domains separated by unconserved intervening linker sequences. To better understand the protein-protein and enzyme-substrate interactions in modular catalysis, we have exploited recent structural insights to prepare stand-alone domains of selected DEBS modules. When combined in vitro, ketosynthase (KS), acyl transferase (AT), and acyl carrier protein (ACP) domains of DEBS module 3 catalyzed methylmalonyl transfer and diketide substrate elongation. When added to a minimal PKS, ketoreductase domains from DEBS modules 1, 2, and 6 showed specificity for the β-ketoacylthioester substrate, but not for either the ACP domain carrying the polyketide substrate or the KS domain that synthesized the substrate. With insights into catalytic efficiency and specificity of PKS modules, our results provide guidelines for constructing optimal hybrid PKS systems.
Modeling and Input Optimization Under Uncertainty for a Collection of RF MEMS Devices

The dynamic response of an RF MEMS device to a time-varying electrostatic force is optimized to enhance robustness to variations in material properties and geometry. The device functions as an electrical switch, where an applied voltage is used to close a circuit. The objective is to minimize the severity of the mechanical impact that occurs each time the switch closes, because severe impacts have been found to significantly decrease the design life of these switches. The switch is modeled as a classical vibro-impact system: a single degree-of-freedom oscillator subject to mechanical impact with a single rigid barrier. Certain model parameters are described as random variables to represent the significant unit-to-unit variability observed during fabrication and testing of the collection of nominally-identical switches; these models for unit-to-unit variability are calibrated to available experimental data. Our objective is to design the shape and duration of the voltage waveform so that impact velocity at switch closure for the collection of nominally-identical switches is minimized subject to design constraints. The methodology is also applied to search for design changes that reduce the impact velocity and to predict the effect of fabrication process improvements.Copyright © 2006 by ASME
Oxygen isotope systematics of biologically mediated reactions of phosphate: I. Microbial degradation of organophosphorus compounds

Microbial activity has been invoked to explain anomalous oxygen isotope compositions of phosphate mineral deposits as well as fossil biogenic apatite. Results of laboratory experiments on enzyme-mediated reactions of phosphate and microbially mediated degradation of organic matter, an important mechanism for the regeneration of dissolved phosphate in modern porewaters, demonstrate that significant exchange of oxygen isotopes between phosphate and water accompanies the hydrolytic cleavage of organically bound phosphate as well as the metabolism of inorganic orthophosphate. Evaluation of the oxygen isotope systematics of microbially mediated reactions of phosphate suggests that oxygen isotope exchange between phosphate and water mediated by bacteria is governed by equilibrium rather than kinetic factors. Under certain conditions, the microbially mediated exchange appears to result in complete re-equilibration of oxygen isotopes between phosphate and water and in other instances equilibrium exchange may be masked by inheritance of phosphate-oxygen from the organic substrate. Analogous microbial processes in natural sediments may be important in the release of dissolved phosphate to pore fluids, precipitation of authigenic apatite, and in the diagenetic alteration of phosphorite deposits and biogenic apatite. These results have important implications for paleoclimatological and paleoenvironmental studies in which oxygen isotope ratios of biogenic phosphate are used as paleotemperature indicators, as well as for studies employing phosphate oxygen isotopes as a tracer of P transport and cycling in the environment.
Effects of ipsilateral rostral pontine reticular lesions on retention of classically conditioned nictitating membrane and eyelid responses

Neural unit recordings from the pontine reticular formation in well-trained rabbits show a tone-evoked onset response (CS), a suggestion of an airpuff onset response (UCS), and an increase in unit activity that is similar to the topography of the learned response. When this same area is destroyed by unilateral electrolytic lesions (in another group of animals), retention of the learned response is abolished but the reflex response is essentially unchanged. Since a recent study (McCormick, Lavond, Clark, Kettner, Rising, & Thompson, 1981) has shown that unilateral cerebellar lesions also produce a complete and selective abolition of the CR, and the CR cannot be reinstated with retraining, these findings are discussed in terms of a common circuitry that encodes the engram for short-delay classical conditioning of striated muscle responses.
Phenotypic suppression of nonsense mutants in yeast by aminoglycoside antibiotics

STREPTOMYCIN, an aminoglycoside antibiotic, can reverse the mutant phenotypes of many nonsense and missense mutations in Escherichia coli and in bacteriophage T4. This phenomenon has been called phenotypic suppression, since the mutant phenotype returns after removal of the drug1. The most likely explanation for phenotypic suppression is that streptomycin promotes mistranslation in vivo, and that acceptable amino acids are inserted into the growing polypeptide chain at the site of the mutant codon. Consistent with this view is the observation that streptomycin causes E. coli ribosomes to mistranslate RNA in vitro2,3. Streptomycin and neomycin have however been found to have no effect in stimulating ribosomes from eukaryotic cells to mistranslate RNA in vitro4,5. A subclass of the aminoglycoside antibiotics has been shown6,7 to stimulate eukaryotic ribosomes to misread RNA. The highly active molecules are distinguished in that they contain the drug fragment paromamine (or 3′-deoxyparomamine). We have therefore examined the capacity of various aminoglycosides to suppress mutations phenotypically in the eukaryotic yeast, Saccharomyces cerevisiae. The results presented here show that paromomycin, which contains paromamine, is capable of phenotypic suppression of the nonsense mutations in S. cerevisiae.
Analysis of the Intermolecular Contacts within Sickle Hemoglobin Fibers: Effect of Site-Specific Substitutions, Fiber Pitch, and Double-Strand Disorder

An atomic model of the sickle hemoglobin (HbS) fiber was synthesized by combining the molecular coordinates of the fiber (obtained from electron microscopy) with atomic coordinates of the sickle hemoglobin double strand (obtained from X-ray crystallography). The model is stereochemically acceptable. The majority of polymerization-sensitive HbS mutants are located at fiber contact sites and the majority of the mutants that do not affect polymerization are not located at contact sites. The residues at intermolecular contacts in the fiber model are reported. We have searched the coordinate space in the vicinity of the EM reconstructions to find models with alternative sets of coordinates that satisfy the mutant data, contain 5-A contacts between double strands, and are stereochemically acceptable. This involved a systematic examination over 297 different models. The alternative fiber models were generated with a range of fiber pitch, double-strand positions, and double-strand polarity. Models which had unacceptably close contacts between atoms, failed to satisfy the mutant data, or did not have 5-A contacts between double strands were considered unacceptable. None of the acceptable alternative fiber models improved the agreement between the polymerization behavior of HbS mutants and their contact site location. However, several models could account for the polymerization data equally well. Residue locations for single-site HbS mutations that could discriminate between alternative fiber models are proposed. The twist of HbS fibers varies in an apparent random manner with an average rotation of 7.8 +/- 2.5 degrees per molecule and a maximum rotation of 16 degrees per molecule. The number of interdouble-strand contacts as a function of fiber twist shows a broad maximum around 9 degrees and may account for the observed range of fiber pitch. This study shows that the upper limit on the fiber twist could result from a loss of axial contacts and repulsive van der Waals interactions between residues involved in interstrand contacts. The loss of axial contacts limits the radial growth of the fiber. In the appendix we analyze the methodology used by I. Cretegny and S. J. Edelstein [(1993) J. Mol. Biol. 230, 733-738] to build a model of the fiber. Our examination reveals shortcomings in the methodology of Cretegny and Edelstein. One result of these shortcomings is that the model synthesized by Cretegny and Edelstein is not stereochemically acceptable because it gives rise to a large number of excessively close (less than 1.4 A) atom-atom contacts, suggesting interpenetration of the molecular envelopes.
Myoglobin O2 desaturation during exercise. Evidence of limited O2 transport.

The assumption that cellular oxygen pressure (PO2) is close to zero in maximally exercising muscle is essential for the hypothesis that O2 transport between blood and mitochondria has a finite conductance that determines maximum O2 consumption. The unique combination of isolated human quadriceps exercise, direct measures of arterial, femoral venous PO2, and 1H nuclear magnetic resonance spectroscopy to detect myoglobin desaturation enabled this assumption to be tested in six trained men while breathing room air (normoxic, N) and 12% O2 (hypoxic, H). Within 20 s of exercise onset partial myoglobin desaturation was evident even at 50% of maximum O2 consumption, was significantly greater in H than N, and was then constant at an average of 51 +/- 3% (N) and 60 +/- 3% (H) throughout the incremental exercise protocol to maximum work rate. Assuming a myoglobin PO2 where 50% of myoglobin binding sites are bound with O2 of 3.2 mmHg, myoglobin-associated PO2 averaged 3.1 +/- .3 (N) and 2.1 +/- .2 mmHg (H). At maximal exercise, measurements of arterial PO2 (115 +/- 4 [N] and 46 +/- 1 mmHg [H]) and femoral venous PO2 (22 +/- 1.6 [N] and 17 +/- 1.3 mmHg [H]) resulted in calculated mean capillary PO2 values of 38 +/- 2 (N) and 30 +/- 2 mmHg(H). Thus, for the first time, large differences in PO2 between blood and intracellular tissue have been demonstrated in intact normal human muscle and are found over a wide range of exercise intensities. These data are consistent with an O2 diffusion limitation across the 1-5-microns path-length from red cell to the sarcolemma that plays a role in determining maximal muscle O2 uptake in normal humans.
Corticosteroid Treatment and Trabecular Meshwork Proteases in Cell and Organ Culture Supernatants

Steroid-induced glaucoma is believed to result from increased aqueous outflow resistance and evidence suggests that this is the result of an excess accumulation of extracellular matrix components. This accumulation could result from an imbalance in the natural turnover of these components. We have investigated the effect of corticosteroid treatment of trabecular meshwork (TM) organ and cell cultures on the extracellular activities of the matrix metalloproteinases and plasminogen activators. We find that corticosteroid treatment results in decreased extracellular activity of stromelysin and tissue plasminogen activator in trabecular meshwork cell culture, and decreased 92 kDa collagenase IV, stromelysin, and tissue plasminogen activator in trabecular meshwork organ culture. These data suggest that decreased levels of proteolytic activities could account, in part, for the accumulation of some extracellular matrix components and be a contributing mechanism in steroid-induced glaucoma.
Drinking, Sex, and Violence on Television: The Cultural Indicators Perspective

This article explores the portrayal of alcohol, alcoholics, and drinking in annual week-long samples of prime-time network dramatic programs. While references to alcohol and drinking have increased rather steadily since 1969, the number of alcoholics in each yearly sample has remained stable. The harmful effects of drinking alcoholic beverages were rarely mentioned. Programs that mention alcohol were also likely to have references to sexual behavior. The characters seen drinking alcoholic beverages—about 37 percent of all major characters—do not differ dramatically from other major characters. Alcoholics, however, are treated quite negatively. Respondents, especially whites and those who have been to college, from the 1977, 1978, 1980 and 1983 NORC General Social Surveys who watch four or more hours of television each day are somewhat less likely to reply that they occasionally drink alcoholic beverages than respondents who watch less television. Data from these surveys also reveal that smoking is positiv...
Statistical analysis of stratified 2x2 tables

Previous papers in this series have discussed design and analysis issues for epidemiologic data that can be presented in a 2 × 2 table.‘” the primary focus was on methods for determining the extent of association between a dichotomous disease state and a dichotomous risk factor. methods appropriate for cross-sectional, prospective, and retrospective studies using matched or unmatched samples were described. In order to study the association between disease status and a dichotomous risk factor, it is often necessary to take into account other variables that may influence either the disease status or the risk factor. For example, Hemming, Overall, and Britt studied the association between the occurrence of nosocomial infections (risk factor) and mortality (disease status) in a large cohort of infants in a newborn intensive care unit. these authors analyzed the data using methods for summarizing the results from a single 2 × 2 table. However, because very low birth weight is associated strongly with both the acquisition of nosocomial infection and mortality, it may be more appropriate to control or adjust for the effects of birthweight.
Teaching Thinking: The Pervasive Approach

Two thinking strategies, concept forma tion and dialectical reasoning, are de scribed. Each seeks the development of students' intellects while helping them learn content. Both have been field- tested with preservice and inservice teachers and appear to satisfy several requirements ofteachers' daily practice.
Innate sensors of influenza virus: clues to developing better intranasal vaccines

Mucosal immunity acquired by natural infection with influenza viruses at the respiratory tract is more effective and cross-protective against subsequent variant virus infection than systemic immunity induced by parenteral immunization with inactivated vaccines. To develop an effective influenza vaccine, it is beneficial to mimic the process of natural infection that bridges innate and adaptive immune systems. The innate immune system that recognizes influenza virus infection consists of several classes of pattern-recognition receptors, including the Toll-like receptors, the retinoic acid-inducible gene-I-like receptors and the NOD-like receptors. Here, we review our current understanding of the mechanism of innate recognition of influenza and how the signals emanating from the innate sensors control adaptive immunity. Further, we discuss the potential roles of these receptors in developing intranasal influenza vaccines.
The Project Manager—Anomalies and Ambiguities

Project managers problems of anomalies and ambiguities in complex missions operation and implementation, discussing interactions with personnel
Putative Nuclear Triiodothyronine Receptors in Tadpole Erythrocytes: Regulation of Receptor Number by Thyroid Hormone

Putative thyroid hormone (TH) receptors have been detected in the nuclei of red blood cells (RBCs) from Rana catesbeiana tadpoles, and their binding characteristics have been examined. Nuclear T3 saturation analyses were carried out in vitro in intact RBCs suspended in phosphate-buffered amphibian Ringer. After incubation with T3, intact nuclei were obtained by centrifugation after lysing the cells in a sucrose-Tris-HCl buffer containing 0.2% saponin and then adding Triton X-100 (final concentration 0.125%) to the lysed mixture to reduce nonspecific binding to less than 10% of total binding. Scatchard analysis of equilibrium binding data revealed that RBCs from premetamorphic (first year) tadpoles contained 502 +/- 39 (SE) T3 binding sites per nucleus; in prometamorphic (second year) tadpoles the number had increased to 844 +/- 39. Development was also accompanied by some increase in the affinity of these sites; dissociation constant (Kd) = 1.8 +/- 0.39 X 10(-11) M and 0.95 +/- 0.108 X 10(-11) M in pre- and prometamorphic tadpoles, respectively. The number of sites per nucleus in both pre- and prometamorphic tadpole RBCs was greatly increased by pretreatment in vivo with either T3 or T4 for 6-10 days; a comparable number of sites per nucleus (2225 +/- 65) was observed after maximal stimulation by either hormone at both stages of development. Significant increases in receptor number were observed 10 days after injection of 0.03 nmol T3 or 0.06 nmol T4 into tadpoles weighing 13-15 g; maximal effects were obtained with 0.1 nmol T3 or 1.0 nmol T4. On the basis of these observations and the evidence that more TH is present in pro- than in premetamorphic tadpoles, it is suggested that the spontaneous increase in receptor number in RBC nuclei associated with progression from the pre- to prometamorphic phase is due, at least in part, to increased levels of endogenous TH.
Aperture based selection for immersive virtual environments

We present two novel techniques for effectively selecting objects in immersive virtual environments using a single 6 DOF magnetic tracker. These techniques advance the state of the art in that they exploit the participant’s visual frame of reference and fully utilize the position and orientation data from the tracker to improve accuracy of the selection task. Preliminary results from pilot usability studies validate our designs. Finally, the two techniques combine to compensate for each other’s weaknesses.
Generative models for fingerprint individuality using ridge models

Generative models of pattern individuality attempt to learn the distribution of observed quantitative features to determine the probability of two random patterns being the same. Considering fingerprint patterns, Gaussian distributions have been previously used for minutiae location and von-Mises distributions for minutiae orientation so as to determine the probability of random correspondence (PRC) between two fingerprints. Motivated by the fact that ridges have not been modeled in generative models and the benefits from ridge points in fingerprint matching, ridge information is incorporated into the generative model by using the distribution for ridge point location and orientation. The proposed model offers a more accurate fingerprint representation from which more reliable PRCs can be computed. Based on parameters estimated from fingerprint databases, PRCs using ridge information are seen to be much smaller than PRCs computed with only minutiae.
Proton di-ionizable p-tert-butylcalix[4]arene-crown-6 compounds in cone, partial-cone and 1,3-alternate conformations: synthesis and alkaline earth metal cation extraction

Novel proton di-ionizable p-tert-butylcalix[4]arene-crown-6 compounds in cone, partial-cone and 1,3-alternate conformations are synthesized to compare the efficiency and selectivity with which they extract alkaline earth metal ions. In these ligands, a crown-6 polyether unit links alternate aromatic rings of the calix[4]arene framework. To the remaining lower-rim positions are attached oxyacetic acid or N-(X)sulfonyl oxyacetamide groups. Changing the conformation varies the spatial relationship between a polyether-complexed divalent metal ion and the ionized side arms of the ligands. This is found to markedly affect the efficiency and selectivity in competitive solvent extraction of alkaline earth metal ions from aqueous solutions into chloroform by the di-ionizable calix[4]arene-crown-6 ligands.
Investigation of Structural and Functional Motifs within the Vaccinia Virus A14 Phosphoprotein, an Essential Component of the Virion Membrane

We have previously reported the construction and characterization of an inducible recombinant virus in which expression of the vaccinia virus membrane protein A14 is experimentally regulated using the tetracycline operator-repressor system. Repression of A14, which results in a 1,000-fold reduction in viral yield, leads to an early block in viral morphogenesis characterized by the accumulation of large virosomes, empty "crescents" that fail to contact these virosomes, and, most strikingly, large numbers of aberrant 25-nm vesicles. Here we report the establishment of a transient-complementation system for the structure-function analysis of A14. We have constructed numerous mutant alleles of A14 designed to identify and test the importance of key structural and sequence motifs within A14, including sites of posttranslational modification, such as glycosylation, phosphorylation, and dimerization. From these studies we have determined that robust complementation ability requires an intact N terminus and two regions flanking the first membrane-spanning domain of A14. We show that A14 is modified by N-linked glycosylation both in vitro and in vivo. However, only a minority of A14 molecules are glycosylated in vivo and these are not encapsidated. In this report we also identify the sole phosphorylated serine residue of A14 as lying within the NHS(85) motif that undergoes glycosylation. Additionally, we show that the Cys(71) residue is required for intermolecular disulfide bond formation and describe the properties of a virus expressing an allele of A14 that cannot form disulfide-linked dimers.
Inhibition of Wnt signaling by Wise (Sostdc1) and negative feedback from Shh controls tooth number and patterning

Mice carrying mutations in Wise (Sostdc1) display defects in many aspects of tooth development, including tooth number, size and cusp pattern. To understand the basis of these defects, we have investigated the pathways modulated by Wise in tooth development. We present evidence that, in tooth development, Wise suppresses survival of the diastema or incisor vestigial buds by serving as an inhibitor of Lrp5- and Lrp6-dependent Wnt signaling. Reducing the dosage of the Wnt co-receptor genes Lrp5 and Lrp6 rescues the Wise-null tooth phenotypes. Inactivation of Wise leads to elevated Wnt signaling and, as a consequence, vestigial tooth buds in the normally toothless diastema region display increased proliferation and continuous development to form supernumerary teeth. Conversely, gain-of-function studies show that ectopic Wise reduces Wnt signaling and tooth number. Our analyses demonstrate that the Fgf and Shh pathways are major downstream targets of Wise-regulated Wnt signaling. Furthermore, our experiments revealed that Shh acts as a negative-feedback regulator of Wnt signaling and thus determines the fate of the vestigial buds and later tooth patterning. These data provide insight into the mechanisms that control Wnt signaling in tooth development and into how crosstalk among signaling pathways controls tooth number and morphogenesis.
Assay validation for left‐censored data

In laboratory validation studies, it is often important to assess agreement between two assays, based on different techniques. Oftentimes, both assays have lower limits of detection and thus measurements are left censored. For example, in studies of Human Immunodeficiency Virus (HIV), the branched DNA (bDNA) assay was developed to quantify HIV-1 RNA concentrations in plasma. Validation of newer assays, such as the RT-PCR (reverse transcriptase polymerase chain reaction) involves assessing agreement of measurements obtained using the two techniques. Both bDNA and RT-PCR assays have lower limits of detection and thus new statistical methods are needed for assessing agreement between two left-censored variables. In this paper, we present maximum likelihood and generalized estimating equations approaches to evaluate agreement between two assays that are subject to lower limits of detection. The concordance correlation coefficient is used as an agreement index. The methodology is illustrated using HIV RNA assay data collected as part of a long-term HIV cohort study.
Knowing from the Armchair that Our Intuitions Are Reliable

In recent years, a growing body of experimental literature has called into question the reliability of our intuitions about hypothetical cases, and thereby called into question the use of intuitions in philosophy. In this paper, I critically assess one prominent example of this challenge, namely, Swain, Alexander, and Weinberg's recent study of order effects on the Truetemp intuition. I argue that die very data that Swain, Alexander, and Weinberg find do not undermine, but instead support, the reliability of intuition. I also show how intuition can itself be marshaled in the service of figuring out just when we can and cannot expect to find order effects on our intuitions.
The diving paradox: new insights into the role of the dive response in air-breathing vertebrates

When aquatic reptiles, birds and mammals submerge, they typically exhibit a dive response in which breathing ceases, heart rate slows, and blood flow to peripheral tissues is reduced. The profound dive response that occurs during forced submergence sequesters blood oxygen for the brain and heart while allowing peripheral tissues to become anaerobic, thus protecting the animal from immediate asphyxiation. However, the decrease in peripheral blood flow is in direct conflict with the exercise response necessary for supporting muscle metabolism during submerged swimming. In free diving animals, a dive response still occurs, but it is less intense than during forced submergence, and whole-body metabolism remains aerobic. If blood oxygen is not sequestered for brain and heart metabolism during normal diving, then what is the purpose of the dive response? Here, we show that its primary role may be to regulate the degree of hypoxia in skeletal muscle so that blood and muscle oxygen stores can be efficiently used. Paradoxically, the muscles of diving vertebrates must become hypoxic to maximize aerobic dive duration. At the same time, morphological and enzymatic adaptations enhance intracellular oxygen diffusion at low partial pressures of oxygen. Optimizing the use of blood and muscle oxygen stores allows aquatic, air-breathing vertebrates to exercise for prolonged periods while holding their breath.
'Candidatus pasteuria usgae' sp. nov., an obligate endoparasite of the phytoparasitic nematode Belonolaimus longicaudatus.

Taxonomically relevant characteristics of a fastidiously Gram-positive, obligately endoparasitic prokaryote (strain S-1) that uses the phytoparasitic sting nematode Belonolaimus longicaudatus as its host are reviewed. 16S rDNA sequence similarity (⩾93 %) confirms its congeneric ranking with other Pasteuria species and strains from nematodes and cladocerans and corroborates morphological, morphometric and host range evidence suggesting a novel taxon. The 16S rDNA sequence of strain S-1 has greatest similarity (96 %) to the 16S rDNA sequences of both Pasteuria penetrans from root-knot nematodes (Meloidogyne species) and the recently reported strain of Pasteuria isolated from the soybean cyst nematode Heterodera glycines. Because the obligately endoparasitic nature of prokaryotes in the genus Pasteuria prevents isolation of definitive type strains, strain S-1 is proposed as ‘Candidatus Pasteuria usgae’ sp. nov.
Bayesian model selection and model averaging

This paper reviews the Bayesian approach to model selection and model averaging. In this review, I emphasize objective Bayesian methods based on noninformative priors. I will also discuss implementation details, approximations, and relationships to other methods. Copyright 2000 Academic Press.
Technology--quality At What Cost

Although medical technology appears to be the driving force behind the rate of increase of real national health expenditures, market imperfections are of greater concern. The market falls short of efficiently allocating health services because of perverse financial incentives and a lack of consumer and physician understanding of the value of many medical services. Making the best use of new and old technology requires better-informed health care decisions, which can help to counter the market imperfections. Cost-effectiveness analysis is presented as one way to assist decisions that must consider the effect of limited resources. Another approach--medical effectiveness--derives from the lack of knowledge about the impact on patient outcomes of many treatments delivered for specific conditions under the average conditions of care in the community. This lack of knowledge led to the development of the medical treatment effectiveness and technology research activities of the Agency for Health Care Policy and Research. The treatment of medical technologies proposed by health reform legislation and by the National Information Infrastructure initiative is briefly discussed. The paper concludes that wise evaluation of new and old technologies--including information systems--is required to improve our patient outcomes, productivity, and enjoyment of life.