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Intrauterine growth restriction (IUGR) occurs naturally in pigs and leads to low birth weight of piglets due to undernutrition caused by placental insufficiency. For 2 main reasons, low birth weight causes economic loss. First, low birth weight pigs have a greater mortality and increasing the litter size causes more low birth weight piglets within litters. Second, surviving low birth weight piglets have reduced performance (i.e., ADG, feed conversion rate, and percentage meat). To develop dietary strategies for preventing IUGR, knowledge of the biological basis of IUGR is required. Muscle fiber number, formed during myogenesis, is correlated positively with performance traits and has been shown in several studies to be reduced in low birth weight pigs. Postnatal muscle hypertrophy is due to satellite cell number per fiber at birth and their rate of proliferation as well as protein deposition (i.e., protein synthesis and degradation). Previous studies and some recent ones indicate that low birth weight littermates in mice are born with fewer satellite cells and studies on pigs show that the rate of satellite cell proliferation may vary within litters. Proteomics studies show that protein synthesis and degradation is downregulated in IUGR pigs and low birth weight pigs also produce meat with less tenderness. Alternative maternal feeding strategies to prevent IUGR have been examined. Increasing maternal global nutrition had no beneficial effect on performance and muscle growth traits in several studies. Feeding excess maternal dietary protein also did not influence muscle growth traits whereas moderately decreased maternal dietary protein may decrease muscle fiber number and performance. On the other hand, addition of L-carnitine to the maternal gestation or lactation diet may increase birth and weaning weights or the muscle fiber number, respectively, in low birth weight pig offspring. Finally, promising data have been obtained on reproductive traits in pigs after addition of functional AA, such as arginine and glutamine, to the gestational diet. Although much is known about the biological basis of IUGR, we still need to learn much more about the mode of action before maternal dietary strategies can be developed to prevent IUGR.

Changes in crystal structure of ettringite on dehydration in normal atmosphere have been re-examined by means of thermogravimetry, X-ray diffraction, and 27Al nuclear magnetic resonance spectroscopy. Synthetic ettringite crystals were heated at various temperatures up to 200°C for durations of up to 7 h. The ettringite structure maintains some long-range order until the coordination number of calcium changes to 5 by dehydration of twelve water molecules from channels and columns with heat treatment at 70°C. When the coordination number of calcium decreases to 5, the short-range order of the structure is disrupted and ettringite becomes X-ray-amorophous. Subsequently, the rest of the water molecules in the columns and bridging OH groups in calcium polyhedra are removed, essentially destroying the framework of the columns. This is accompanied by changes in the coordination number of aluminium from 6 to 4.Changes in crystal structure of ettringite on dehydration in normal atmosphere have been re-examined by means of thermogravimetry, X-ray diffraction, and 27Al nuclear magnetic resonance spectroscopy. Synthetic ettringite crystals were heated at various temperatures up to 200°C for durations of up to 7 h. The ettringite structure maintains some long-range order until the coordination number of calcium changes to 5 by dehydration of twelve water molecules from channels and columns with heat treatment at 70°C. When the coordination number of calcium decreases to 5, the short-range order of the structure is disrupted and ettringite becomes X-ray-amorophous. Subsequently, the rest of the water molecules in the columns and bridging OH groups in calcium polyhedra are removed, essentially destroying the framework of the columns. This is accompanied by changes in the coordination number of aluminium from 6 to 4.

NCTR measured sphinganine concentrations in the livers of mice and in the livers and kidneys of rats in conjunction with a tumour bioassay. In our model of the tumour incidence, target-tissue levels of sphinganine serve as a biomarker for a dose response of fumonisin B1 on cell death. Initially we questioned the utility of sphinganine levels in this role because they were highly variable when compared across time points. In spite of this concern, a conceptual framework and data are presented that support the use of sphinganine as a biomarker for a dose response of fumonisin B1 on cell death. This framework is reasonably consistent with observed sphinganine concentrations in the examined tissues, the literature on fumonisin's effects on sphingolipid synthesis, and our hypothesized mechanism through which fumonisin B1 increases age-specific tumour incidence.

C-S-H samples were precipitated from aqueous solution containing Ca(NO3)2and Na2SiO3with an initial Ca/Si molar ratio of 1·3, when the pH value in the solution was varied by adding HNO3or NaOH. A pH > 10·9 was required to obtain quasi-crystalline C-S-H, and the CaO/SiO2ratio of the precipitate was increased with increasing pH, reaching a maximum close to the initial ratio at pH > 13. C-S-H was also precipitated with varying initial Ca/Si molar ratios at pH > 13. It was shown that the CaO/SiO2ratios can be controlled by either varying the pH value at given initial Ca/Si ratios, or by varying the initial Ca/Si ratios at pH > 13. The C-S-H samples were investigated using X-ray diffraction and 29Si nuclear magnetic resonance spectroscopy, which identifies the connectivity of silica tetrahedra (Qx). The interlayer spacing decreased linearly, and Q1/(Q1+ Q2+ Q3) ratios increased with increasing CaO/SiO2ratios. A good correlation between Q1/(Q1+ Q2+ Q3) ratios and interlayer spacing was observed.C-S-H samples were precipitated from aqueous solution containing Ca(NO3)2and Na2SiO3with an initial Ca/Si molar ratio of 1·3, when the pH value in the solution was varied by adding HNO3or NaOH. A pH > 10·9 was required to obtain quasi-crystalline C-S-H, and the CaO/SiO2ratio of the precipitate was increased with increasing pH, reaching a maximum close to the initial ratio at pH > 13. C-S-H was also precipitated with varying initial Ca/Si molar ratios at pH > 13. It was shown that the CaO/SiO2ratios can be controlled by either varying the pH value at given initial Ca/Si ratios, or by varying the initial Ca/Si ratios at pH > 13. The C-S-H samples were investigated using X-ray diffraction and 29Si nuclear magnetic resonance spectroscopy, which identifies the connectivity of silica tetrahedra (Qx). The interlayer spacing decreased linearly, and Q1/(Q1+ Q2+ Q3) ratios increased with increasing CaO/SiO2ratios. A good correlation between Q1/(Q1+ Q2+ Q3) ratios and interlayer spacing was observed.

This study describes the baseline haematology and serum chemistry values found in non-pregnant, pregnant (gestational days [GD] 2-21) and lactating (postnatal days 1-9) Sprague Dawley rats (n= 3-10/day) from the NCTR breeding colony of Cr1:COBS CD(SD)BR strain. Maternal body weights on GD0 ranged from 250 to 300 g. Multiple analytes were measured in both whole blood and serum of dams. Amniotic fluid, fetal serum, and postnatal pup serum analyte values were also acquired. Maternal blood was collected from the heart under sub-terminal carbon dioxide (CO2) anaesthesia. Most pregnant dam blood values were not appreciably different from values for non-pregnant dams until near term; near-term values for some analytes (red blood cells, haemoglobin, haematocrit, mean corpuscular haemoglobin concentration, alkaline phosphatase, albumin, total protein, glucose, total bilirubin, sodium, and chloride) decreased but returned to near-normal values soon after delivery. The most dramatic change was a three-fold elevation of serum triglyceride levels near term with a subsequent decrease at birth. Most serum chemistry analytes measured in progeny increased after birth except for alkaline phosphatase, calcium and potassium levels which decreased.

The metabolism and disposition of [6,7-3H]estradiol ([3H]E2) given by gavage (po) or intravenously (iv) were examined in female B6C3F1 mice fed either the purified AIN-76A (AIN) or cereal-based NIH-07 (NIH) diet for a period of 8 weeks prior to treatment with E2. Initially, 40.6 Ci of [3H]E2 was given iv to each mouse. Subsequently, 45.6 Ci of [3H]E2 was given po to the same mice. Samples of blood, urine, and feces were obtained during a 48-hr period after each dosing. Total radioactivity was determined for each sample. Urine and plasma samples were analyzed by HPLC, and the radiolabeled metabolites were tentatively identified and quantified. Statistical comparisons were made of the effects of diet, route of administration, and interactions among groups. Analysis revealed: 1) greater fecal than urinary excretion of radioactivity regardless of route of administration or diet fed, 2) more radioactivity excreted in the urine of AIN-fed than in NIH-fed mice, significantly different only after iv administration (p less than 0.02), and 3) a greater feces:urine ratio of excreted radioactivity following iv than po administration and from NIH-than AIN-fed mice. Metabolite profiles showed: 1) no differences in urine due to route of administration, 2) estriol conjugates dominated urinary metabolites, 3) accumulation of radioactive material in plasma that apparently was tritiated water, with more rapid accumulation of tritiated water after po than iv administration, 4) relatively more plasma estradiol-17-glucuronide, estriol-3-sulfate, and estriol in po- than in iv-treated mice, 5) estradiol-3, 17-sulfate in plasma of iv- but not po-treated mice.(ABSTRACT TRUNCATED AT 250 WORDS)

This study demonstrated the utility of negative ion atomospheric pressure ionization mass spectrometry for the routine quantitation of 2,4,5-trichlorophenoxyacetric acid and its glycine and taurine amide metabolites in mouse blood, urine and feces samples. The quantitation of 2,4,5-trichlorophenoxyacetic acid in blood follows a short cleanup procedure and used 2,4,5-trichlorophenoxy-13C6-acetic acid as the stable label isotope diluent. A more extensive cleanup procedure utilizing high-pressure liquid chromatography was required for the determination of 2,4,5-trichlorophenoxyacetic acid and its two metabolites in urine and feces. The glycine amide metabolite was quantitated by the 13C stable label isotope diluent method. The taurine amide relied on an initial separation step followed by using a second 2,4,5-trichlorophenoxy-13C6-acetic acid spike for its isotope diluent. Alkaline hydrolysis of the metabolites, followed by methylation, allowed the methyl ester of 2,4,5-trichlorophenoxyacetic acid to be solely used as the analyte in the negative ion atmospheric pressure ionization mass spectrometry quantitation step.

DSP (densified with small particles) cement pastes, made from white Portland cement and silica fume, were autoclaved at temperatures of up to 240°C. The hydration products were characterized using X-ray powder diffraction, 29Si nuclear magnetic resonance spectroscopy and scanning electron microscopy. The influences ofCaO/SiO2 ratio, autoclave temperature and time of reaction were studied. Semi-crystalline calcium silicate hydrate was the major product at low temperatures, with xonotlite, tobermorite, gyrolite, kilchoanite and 8CaO·5SiO2 present at higher temperatures. The nature of the crystalline phase depends on the initial CaO/SiO2 molar ratio; at 240°C, a distinct change in chemistry appears to occur between CaO/SiO2 ratios of 1·3 and 1·1. NMR spectroscopy has proved to be an effective means of studying the polymerization of silicates.DSP (densified with small particles) cement pastes, made from white Portland cement and silica fume, were autoclaved at temperatures of up to 240°C. The hydration products were characterized using X-ray powder diffraction, 29Si nuclear magnetic resonance spectroscopy and scanning electron microscopy. The influences ofCaO/SiO2ratio, autoclave temperature and time of reaction were studied. Semi-crystalline calcium silicate hydrate was the major product at low temperatures, with xonotlite, tobermorite, gyrolite, kilchoanite and 8CaO·5SiO2present at higher temperatures. The nature of the crystalline phase depends on the initial CaO/SiO2molar ratio; at 240°C, a distinct change in chemistry appears to occur between CaO/SiO2ratios of 1·3 and 1·1. NMR spectroscopy has proved to be an effective means of studying the polymerization of silicates.

This study has shown that both?- anda'-C2S can be readily stabilized by suitable doping with BaO, B2O3, and P2O5, using a single firing at 1450° C. The?-C2S samples all have similar lamellar structures, irrespective of the dopant present, which show (100) twinning. Grain boundary phases are present in all?-C2S preparations. Thea'-C2S crystals usually contain precipitates and associated strain fields and dislocations, but a grain boundary phase was only observed ina'-C2S stabilized by BaO. Some correlation between reactivity and presence of dislocations and strain fields has been suggested for thea'-C2S phase.

Reactions of colloidal silica fumes with calcium hydroxide or hydrating tricalcium silicate (C3S) have been studied using calorimetry, chemical analyses, and scanning electron microscopy. Silica fume reacts immediately with calcium hydroxide forming a colloidal calcium silicate hydrate (C-S-H) similar to that formed by the hydration of C3S. When excess silica is present it reacts with C-S-H already formed to produce a new, highly polymerized C-S-H, having a very low C/S ratio (1.0). Silica fume accelerates the hydration of C3S, reduces the amount of calcium hydroxide formed by reacting with it, and slightly lowers the C-S-H ratio of the C-S-H formed by hydration. When large amounts of silica fume are present the formation of calcium hydroxide may be entirely suppressed and a highly polymerized C-S-H is formed. Silica fume is considered a good model for reactive pozzolans used in concrete.

The wide variations in urinary bladder and colo-rectal cancer incidence in humans have been attributed in part to metabolic factors associated with exposure to carcinogenic aromatic and heterocyclic amines. Cytochrome P-4501A2 (CYP1A2), which catalyses N-oxidation, and acetyltransferase (NAT2) which catalyses N- and O-acetylation, both appear to be polymorphically distributed in human populations; and slow and rapid NAT2 phenotypes have been implicated as risk factors for these cancers. Caffeine has also been shown to undergo 3-demethylation by CYP1A2, and it is further acetylated to 5-acetylamino-6-formylamino-3-methyluracil (AFMU) by the polymorphic NAT2. In this report, we describe a metabolic phenotyping procedure that can be used to determine concomitantly the hepatic CYP1A2 and NAT2 phenotypes. For the NAT2 phenotype, we confirm the valid use of the urinary molar ratio of AFMU/1-methylxanthine, even in alkaline urines. For the CYP1A2 phenotype, the urinary molar ratio of [1,7-dimethylxanthine+ 1,7-dimethyluric acid]/caffeine, taken at 4–5 h after caffeine ingestion, was identified from pharmacokinetic analyses of 12 subjects as being better correlated (r = 0.73; p= 0.007) with the rate constant for caffeine 3-demethylation than other previously suggested ratios. This procedure was then used to determine the CYP1A2 phenotype in subjects from Arkansas (n = 101), Italy (n =95), and China (n = 78). Statistical and probit analyses of nonsmokers indicated that the CYP1A2 activity was not normally distributed and appeared trimodal. This trimodality allowed arbitrary designation of slow, intermediate, and rapid phenotypes, which ranged from 12–13 slow, 51–67 intermediate, and 20–37 rapid, in the different populations. A reproducibility study of 13 subjects over a 5 day or 5 week period showed that, with one exception, intraindividual variability did not alter this CYP1A2 phenotypic classification. Induction of CYP1A2 by cigarette smoking was also confirmed by the increased caffeine metabolite ratios observed in the Arkansas and Italian smokers (blonde tobacco). However, Italian smokers of black tobacco and Chinese smokers did not appear to be induced. Furthermore, probit analyses of Arkansas and Italian blonde tobacco smokers could not discriminate between phenotypes, apparently as a consequence of enzyme induction.

Using a pulsed-hollow-cathode discharge, we have observed the emission spectra of core-excited levels of Na i and Mg ii. Line identifications and implications for extreme-ultraviolet lasers are discussed.

The paper reviews both the properties and the applications of core-excited metastable atoms. The production of these atoms by microwaves, pulsed hollow-cathode discharges, and laser-produced x rays is described. We discuss the application of these atoms to several new types of spectroscopy that allow autoionizing linewidths as narrow as 0.1 cm^−1 to be measured. The application of these metastables to the generation of picosecond-time-scale soft-x-ray pulses and to XUV lasers is also discussed.

PURPOSE: This study was undertaken to audit the results of endoanal ultrasound in patients with fecal incontinence. METHODS: Endoanal ultrasound was used to investigate 53 patients with fecal incontinence. Data for endoanal ultrasound were collected prospectively. Results were compared with clinical and obstetric history, obtained retrospectively from case notes, and were compared with manometric and operative findings. RESULTS: Sphincter abnormalities were identified in 42 of 53 patients. A total of 28 anterior defects were thought to be obstetric in origin. Fourteen other defects were secondary to anal pathology or surgery. Patients with anterior external sphincter defects either had complete defects (4 patients; mean age, 31 years) or proximal defects (24 patients; mean age, 55 years). For patients with a proximal defect, 38 percent gave a history of obstetric tear, episiotomy, or forceps delivery, and the rest declared having had an apparently normal delivery. Only 50 percent had a sphincter weakness that was evident on clinical examination. Of those studied with manometry, only 21 percent had low squeeze pressures consistent with an external sphincter defect. CONCLUSIONS: Sphincter defects seen on ultrasound may not have a history of obstetric trauma or abnormal clinical and manometric findings. Endoanal ultrasound is recommended in all patients with fecal incontinence to detect occult sphincter defects.

A large dielectric measurement cell, with 54 ml sample volume, was designed and calibrated to operate over a 1 MHz-3 GHz frequency range. The cell was used to measure the dielectric constants and conductivities of concretes over a broad frequency range and different curing times. The water/cement/sand ratios of the concrete were changed to study the dependence of the electromagnetic properties on them. Chemical admixtures to retard and accelerate the curing process of concretes were also added. It was found that the electromagnetic properties of concretes vary significantly over the frequencies. Furthermore, during the curing process, the water/cement/sand ratios and chemical admixtures of concretes affected their electromagnetic properties. A relationship of the electromagnetic properties of concretes to their various physical states and constituent components could be used for the quality control of concretes in construction work.

Comparative analysis of the amino acid sequences of hemagglutinins (HAs) of influenza B/Lee/40, B/Md/59, and B/HK/73 viruses has allowed examination of the molecular basis of antigenic variation in type B viruses. As seen with influenza type A viruses, antigenic drift in influenza B viruses proceeds mostly through the accumulation of amino acid substitutions within the HA1 portion of the HA molecule. However, the rate of variation observed among the influenza B virus HAs appears to be significantly lower than the observed rate of variation among influenza A virus HAs. The overall rate of amino acid change in the HA1s of the influenza B viruses studied is 2% per 10 years, whereas the HA1s of H3 influenza A viruses vary by 9.2% per 10 years. The sequences of the influenza B HAs were also examined in relation to the three-dimensional model for the A/Aichi/2/68 HA. When the primary amino acid sequences are compared, it appears that most of the important structural features of the type A HAs--such as the sialic acid binding site, the disulfide linkages, and the stem structure of the trimer--are conserved in the influenza B virus HAs. Regions are also identified where extensive amino acid substitutions have occurred among the three antigenically distinct influenza B virus HAs. The locations of these areas in the B HA structure correspond to antigenic regions proposed for the A virus HAs. In addition, modulation of antigenic regions in B virus HAs may also occur through amino acid deletions and variation in glycosylation sites.

In June of 1977, a new influenza A pandemic was started by strains of the H1N1 serotype. Oligonucleotide fingerprint analysis of the RNA from viruses isolated during the early stage of this pandemic demonstrated that genetic variation among these 1977 strains could be attributed to sequential mutation [Young, J.F., Desselberger, U. & Palese, P. (1979) Cell, 18, 73-83]. Examination of more recent strains revealed that the H1N1 variants that were isolated in the winter of 1978-1979 differed considerably from the H1N1 viruses isolated the previous year. Oligonucleotide and peptide map analysis of the new prototype strain (A/Cal/10/78) suggested that it arose by recombination. It appears that only the HA, NA, M, and NS genes of this virus are derived from the earlier H1N1 viruses and that the P1, P2, P3, and NP genes most likely originate from an H3N2 parent. These data suggest that genetic variation in influenza virus strains of the same serotype is not restricted to mutation alone, but can also involve recombination (reassortment).

RNA segment 8 of the influenza A virus genome codes for two nonstructural proteins, NS1 and NS2, for which the functions are unknown. Cloned cDNA copies of this gene from three different influenza A virus strains were inserted into an Escherichia coli plasmid expression vector, pAS1, carrying the strong regulatable lambda phage promoter, PL. After induction, the NS1 proteins were overproduced to levels of 20-25% of total cellular protein. This was surprising in that the codon composition for these eukaryotic genes is similar to that for weakly expressed proteins in E. coli. Thus, under the appropriate conditions, it appears that high level expression of genes containing a relatively large proportion of minor codons can be obtained. The NS1 protein produced in bacteria from a cloned cDNA copy of the A/PR/8/34 virus NS gene was purified to apparent homogeneity and used to generate a high-titer monospecific rabbit antiserum. Immunoprecipitation studies showed this antibody to be crossreactive against the NS1 proteins produced by several different influenza A virus strains. Immunofluorescence experiments in Madin-Darby canine kidney cells showed the NS1 proteins to be located in the nucleoplasm early in infection for all strains examined. With some of the strains, NS1-specific immunofluorescence was observed predominantly in the nucleoli later in infection. This technology can be used to obtain other viral proteins in pure form for structural, functional, and immunological studies.

We have tested the ability of the c13 protein, which is a hybrid protein of the first 81 amino acids of the viral nonstructural protein (NS1) and the HA2 subunit of viral hemagglutination produced in E. coli, to render target cells susceptible to the lytic activity of influenza virus-specific cytotoxic T lymphocytes (CTL). The results showed that P815 cells coated with c13 protein were lysed by PR8 virus-induced secondary CTL derived from BALB/c mice. Cold-target inhibition tests clearly demonstrated that c13 protein-coated P815 cells were recognized by an H1 subtype-specific CTL population. Furthermore, PR8 virus-induced CTL derived from C3H mice did not lyse c13 protein-coated P815 cells, suggesting that c13 protein was recognized by CTL in conjunction with H-2d products. These findings suggest that this protein interacts with the cellular plasma membrane and makes target cells recognizable by H-2-restricted, influenza virus subtype-specific CTL.

We have tested the abilities of various polypeptides of A/PR/8/34 (H1N1) virus, constructed by recombinant DNA techniques, to induce influenza virus-specific secondary cytotoxic T lymphocyte (CTL) responses. A hybrid protein (c13 protein), consisting of the first 81 amino acids of viral nonstructural protein (NS1) and the HA2 subunit of viral hemagglutinin (HA), induced H-2-restricted, influenza virus subtype-specific secondary CTL in vitro, although other peptides did not. Using a recombinant virus, the viral determinant responsible for recognition was mapped to the HA2 portion of c13 protein. Immunization of mice with c13 protein induced the generation of memory CTL in vivo. The CTL precursor frequencies of A/PR/8/34 virus- and c13 protein-immune mice were estimated as one in 8,047 and 50,312, respectively. These results indicate that c13 protein primed recipient mice, even though the level of precursor frequency was below that observed in virus-immune mice.

The complete nucleotide sequences of the NS genes from three human influenza viruses, A/FM/1/47 (H1N1), A/FW/1/50 (H1N1), and A/USSR/90/77 (H1N1), were determined. Only five single-base differences were found within the sequences of the A/FW/1/50 and A/USSR/90/77 NS genes, thus confirming earlier data suggesting that the 1977 H1N1 viruses are closely related to virus strains that were circulating around 1950. Comparison of all three sequences with those from A/PR/8/34 and A/Udorn/72 viruses illustrates that these genes (with the exception of that of the A/USSR/90/77 strain) evolve through cumulative base changes along a single common lineage. A nucleotide sequence variation of approximately 2.2 to 3.4% per 10 years was determined for the NS gene segments. Extensive size variation was also observed among the NS1 proteins of the various human viruses. The A/FM/1/47 NS1 protein, which consists of 202 amino acids, is 15% shorter than the A/Udorn/72 NS1 protein, which consists of 237 amino acids.

The current vaccine against tuberculosis, Mycobacterium bovis strain bacille Calmette-Guerin (BCG), offers potential advantages as a live, innately immunogenic vaccine vehicle for the expression and delivery of protective recombinant antigens (Stover, C.K., V.F. de la Cruz, T.R. Fuerst, J.E. Burlein, L.A. Benson, L.T. Bennett, G.P. Bansal, J.F. Young, M.H. Lee, G.F. Hatfull et al. 1991. Nature [Lond]. 351:456; Jacobs, W.R., Jr., S.B. Snapper, L. Lugosi and B.R. Bloom. 1990. Curr. Top. Microbiol. Immunol. 155:153; Jacobs, W.R., M. Tuckman, and B.R. Bloom. 1987. Nature [Lond.]. 327:532); but as an attenuated intracellular bacterium residing in macrophages, BCG would seem to be best suited for eliciting cellular responses and not humoral responses. Since bacterial lipoproteins are often among the most immunogenic of bacterial antigens, we tested whether BCG expression of a target antigen as a membrane-associated lipoprotein could enhance the potential for a recombinant BCG vaccine to elicit high-titered protective antibody responses to target antigens. Immunization of mice with recombinant BCG vaccines expressing the outer surface protein A (OspA) antigen of Borrelia burgdorferi as a membrane-associated lipoprotein resulted in protective antibody responses that were 100-1,000-fold higher than responses elicited by immunization with recombinant BCG expressing OspA cytoplasmically or as a secreted fusion protein. Furthermore, these improved antibody responses were observed in heterogeneous mouse strains that vary in their immune responsiveness to OspA and sensitivity to BCG growth. Thus, expression of protective antigens as chimeric membrane-associated lipoproteins on recombinant BCG may result in the generation of new candidate vaccines against Lyme borreliosis and other human or veterinary diseases where humoral immunity is the protective response.

We have examined whether active immunization with c13 protein, a hybrid protein of the first 81 amino acids of the viral NS1 nonstructural protein and the HA2 subunit of A/PR/8 (H1N1) hemagglutinin, could protect BALB/c mice from challenge with A/PR/8 H1 subtype virus. Mice immunized with the c13 protein had a significant reduction of pulmonary virus titers with A/PR/8 (H1) virus, but failed to limit the replication of A/PC (H3) virus, which reflects the in vitro CTL activity of c13 immune spleen cells. We observed that the epitope recognized by HA2 specific CTL, which are induced by a derivative of c13 protein, is highly conserved among H1 and H2 subtype virus strains. This led us to test whether active immunization with c13 protein would also limit pulmonary virus replication in mice infected with the A/TW virus, a virus of the H1 subtype, which was isolated in 1986, and with a virus of the H2 subtype, A/Japan/305/57. Immunized mice had significantly lower lung virus titers than did control mice, and did not possess any neutralizing antibodies to the challenger viruses. These results indicate that active immunization with a fusion protein containing the cross-reactive CTL epitope protects mice from influenza infection by inducing CTL against influenza A H1 and H2 subtype virus strains, which markedly vary in their antibody binding sites on the HA1. The ability to induce active cross-reactive immunization with a fusion protein which contains a highly conserved CTL epitope offers a model for vaccine approaches against viruses which undergo significant variations in their antibody binding sites.

Slow hydration of γ-C2S in mixtures of β and γ polymorphs was observed between 17 and 40 months of curing, but did not occur in the presence of silica fume. The detection of cross-linked silicate species by nuclear magnetic resonance (Q3) is attributed to the formation of silica gel because of the low effective CIS molar ratio in mixtures containing silica fume. The formation of ettringite from additons of C4A3S and gypsum prevents the hydration of β-C2S unless free lime is also present in the mixture.Slow hydration of γ-C2S in mixtures of β and γ polymorphs was observed between 17 and 40 months of curing, but did not occur in the presence of silica fume. The detection of cross-linked silicate species by nuclear magnetic resonance (Q3) is attributed to the formation of silica gel because of the low effective CIS molar ratio in mixtures containing silica fume. The formation of ettringite from additons of C4A3S and gypsum prevents the hydration of β-C2S unless free lime is also present in the mixture.

The strength development and hydration of β- and γ-C2S mixes in the presence of silica fume, calcium sulphoaluminate and gypsum is strongly accelerated due to ettringite and C—S—H formation. Calcium sulphoaluminate contributes to strength only when conditions are modified to maximize the formation of ettringite. Therefore an addition of free CaO is needed in samples with low β-C2S content. Strength in samples without C4A3S is lower because it depends on C—S—H formation. γ-C2S hydration is neglibible compared with β-C2S hydration, remaining unreacted even after more than one year in water.The strength development and hydration of β- and γ-C2S mixes in the presence of silica fume, calcium sulphoaluminate and gypsum is strongly accelerated due to ettringite and C—S—H formation. Calcium sulphoaluminate contributes to strength only when conditions are modified to maximize the formation of ettringite. Therefore an addition of free CaO is needed in samples with low β-C2S content. Strength in samples without C4A3S is lower because it depends on C—S—H formation. γ-C2S hydration is neglibible compared with β-C2S hydration, remaining unreacted even after more than one year in water.

A cDNA library was constructed with poly(A)+-mRNAs from NDV-Italien infected BHK-21 cells. A clone, that hybridized to the F gene mRNA, was sequenced. A long open reading frame encodes for a protein of 553 amino acids, with a calculated molecular weight of 59,153, consisting of twelve cysteine residues and six potential glycosylation sites. The protein sequence contains a hydrophobic region at the N-terminus of F1and a presumptive long transmembrane fragment near the C-terminus.

The complete nucleotide sequence of the hemagglutinin (HA) gene of a type B influenza virus (B/Lee/40) was obtained by using cloned cDNA derived from the RNA segment. The gene is 1,882 nucleotides long and can code for a protein precursor of 584 amino acids. Structural features common to type A virus HAs are also conserved in the B virus HA. These include a hydrophobic signal peptide, hydrophobic NH2 and COOH termini of the HA2 subunit, and a HA1/HA2 cleavage site involving an arginine residue. The sequence of the B HA gene and its deduced amino acid sequence were compared to those of a type A influenza virus (A/PR/8/34). When these two genes were aligned, it was found that 24% of the amino acids in the HA1 subunits and 39% of the amino acids in the HA2 subunits are conserved. This degree of relatedness between type B virus and type A virus HAs (intertypic comparison) is similar to the homologies observed among certain type A virus HAs (intratypic comparison). A close evolutionary relationship is therefore suggested between the HAs of type A and type B influenza viruses.

Summary Lignosulphonates modify the hydration of tricalcium aluminate: acicular crystals form instead of the usual hexagonal plates, and by X-ray diffraction, DTA* and optical data it has been shown that these can represent more than one hydration product. The differences in reaction products are attributed to small changes in hydration conditions. In pastes of tricalcium aluminate, C2AH8† and C4AH13crystallize with a new crystal habit, rather than forming a new hydrate. Current theories explaining the effect of lignosulphonates on the mechanical strengths of concrete are discussed.Summary Lignosulphonates modify the hydration of tricalcium aluminate: acicular crystals form instead of the usual hexagonal plates, and by X-ray diffraction, DTA* and optical data it has been shown that these can represent more than one hydration product. The differences in reaction products are attributed to small changes in hydration conditions. In pastes of tricalcium aluminate, C2AH8† and C4AH13 crystallize with a new crystal habit, rather than forming a new hydrate. Current theories explaining the effect of lignosulphonates on the mechanical strengths of concrete are discussed.

This paper stresses the continuing education of engineers in industry for the period 1960–1969. The forces conditioning engineering education are delineated with particular emphasis on the acceleration of technology and the shift in importance of diagnosis. Engineering education courses designed to meet the new demands are described. Discussed are the influences that will shape the next decade. They will be dominated by “new” concerns for human problems and the task of setting priorities.

Optical gain was observed on the B ? X transition of the Cs^2+F^− ionic excimer molecule at 185 nm. The excimer was produced by photoionization of CsF vapor with a laser-produced plasma source. An average net gain coefficient of 0.3 cm^−1 was measured for 7 Torr of CsF and a 225-mJ pump laser.

We report the observation of laser gain in the vacuum ultraviolet pumped by super Coster–Kronig decay. Using a 5-J, 300-psec pump pulse of 1064-nm radiation, we have observed gain on transitions in Zn iii at 127.0, 130.6, and 131.9 nm with total gains of exp(2.4), exp(5.1), and exp(3.2), respectively. The large branching ratios of the rapid super Coster–Kronig decay into a small number of final levels makes high-efficiency operation possible.

We describe the construction and operation of a 109-nm, photoionization-pumped, single-pass laser in Xe iii. The laser is pumped by soft x rays emitted from a laser-produced plasma in a traveling-wave geometry. Using a 3.5-J, 300-psec, 1064-nm laser pump pulse, we measure a small-signal gain coefficient of 4.4 cm^−1 and a total small-signal gain of exp(40). The laser is fully saturated and produces an output energy of 20 μJ in a beam with 10-mrad divergence.

Experimental observation of a laser-induced dipole–quadrupole collision between Sr and Ca is reported. The laser-induced collision cross section peaks at an applied photon energy equal to the energy defect of the initial and final states of the infinitely separated atoms. A cross section of 3 × 10^−14 cm^2 was induced at a laser-power density of 7 × 10^9 W/cm^2; the linewidth was 20 cm^−1.

We report the use of a new extreme-ultraviolet radiation source based on spontaneous anti-Stokes scattering for high-resolution absorption spectroscopy of transitions originating from the 3p^6 shell of potassium. The region from 546.6 to 536.8 Å is scanned at a resolution of about 1.2 cm^−1. Within this region, four previously unreported lines are observed.

Optical gain was observed on the B ? X transition of the Cs^2+F^- ionic excimer molecule at 185 nm. The excimer was produced by photoionization of CsF vapor with a laser-produced plasma source. An average net gain coefficient of 0.3 cm^-1 was measured for 7 Torr of CsF and a 225-mJ pump laser.

Experimental observation of a laser-induced dipole-quadrupole collision between Sr and Ca is reported. The laser-induced collision cross section peaks at an applied photon energy equal to the energy defect of the initial and final states of the infinitely separated atoms. A cross section of 3 × 10^-14 cm^2 was induced at a laser-power density of 7 × 10^9 W/cm^2; the linewidth was 20 cm^-1.

A cw dye laser is described that provides tunable, high-power single-frequency radiation over the entire visible spectrum. Central to the design is the elimination of spatial hole burning and the enhancement of mode competition through the use of a ring resonator and a very-low-loss Faraday-effect device to select a single traveling-wave direction. As much as 0.9 W of single-frequency 580-nm radiation is available from rhodamine 6G using a 4-W 514.5-nm argon-ion laser pump. Intracavity second-harmonic generation has produced over 20 mW of tunable single-frequency ultraviolet radiation under the same conditions.

We report the observation of atomic-pair absorption in barium and in barium–thallium vapors using a white-light source. At atomic densities on the order of 10^17 atoms/cm^3 we measure absorptions of 2.9% cm^−1 for Ba–Ba and 2.3% cm^−1 for Ba–Tl. In both cases, the absorption maxima occur at the predicted (R = ∞) wavelength and have a full width at half maximum of approximately 15 cm^−1.

We report extensive measurements of gain in the Xe III system initially observed by Kapteyn et al. [Phys. Rev. Lett. 57, 2939 (1986)]. The dependence of this gain on pressure, pumping-pulse length, and pump energy is presented. By optimizing these parameters we have achieved a gain of exp(3.2) by using only 0.56 J of 1064-nm energy on target, representing an efficiency improvement of nearly 100. Total gains as high as exp(6.6) have been measured when using higher energies. Our data indicate that effective laser-produced plasmas can be created with applied power densities as low as 5 × 10^10 W cms^−2.