Search

Freshwater export from the Arctic is critical in determining the density of water at sites of North Atlantic deep water formation, which in turn influences the global flux of oceanic heat and nutrients. We need geochemical tracers and high‐resolution observations to refine our freshwater budgets and constrain models for future change. The use of seawater barium concentrations in the Arctic Ocean as a freshwater tracer relies on the conservative behavior of barium in seawater; while this has been shown to be an unreliable assumption in Arctic summers, there are a lack of studies observing seasonal progressions. Here, we present barium concentrations from seawater and sea‐ice collected during the Norwegian Young Sea ICE expedition from boreal winter into summer. We use other tracers (salinity, oxygen isotopes, and alkalinity) to reconstruct freshwater inputs and calculate a barium “deficit” that can be attributed to nonconservative processes. We locate a deficit in winter when biological production is low, which we attribute to uptake by barite formation associated with old organic matter or by internal sea‐ice processes. We also find a significant barium deficit during the early spring bloom, consistent with uptake into organic‐matter associated microenvironments. However, in summer, there no strong barium deficit near the surface, despite high biological production and organic carbon standing stocks, perhaps reflecting phytoplankton assemblage changes, and/or rapid internal cycling. Our findings challenge the assumptions surrounding the use of barium as an Arctic freshwater tracer, and highlight the need to improve our understanding of barium in sea‐ice environments. We provide a time series of seawater barium measurements from the Arctic winter through summerWe provide evidence for nonconservative behavior of barium in sea‐iceOur findings show that the assumptions surrounding the use of barium as a freshwater tracer in the Arctic need to be challenged

ABSTRACTHerein we describe the changes in the gene expression profile of Candida parapsilosisassociated with the acquisition of experimentally induced resistance to azole antifungal drugs. Three resistant strains of C. parapsilosiswere obtained following prolonged in vitroexposure of a susceptible clinical isolate to constant concentrations of fluconazole, voriconazole, or posaconazole. We found that after incubation with fluconazole or voriconazole, strains became resistant to both azoles but not to posaconazole, although susceptibility to this azole decreased, whereas the strain incubated with posaconazole displayed resistance to the three azoles. The resistant strains obtained after exposure to fluconazole and to voriconazole have increased expression of the transcription factor MRR1, the major facilitator transporter MDR1, and several reductases and oxidoreductases. Interestingly, and similarly to what has been described in C. albicans, upregulation of MRR1and MDR1is correlated with point mutations in MRR1in the resistant strains. The resistant strain obtained after exposure to posaconazole shows upregulation of two transcription factors (UPC2and NDT80) and increased expression of 13 genes involved in ergosterol biosynthesis. This is the first study addressing global molecular mechanisms underlying azole resistance in C. parapsilosis; the results suggest that similarly to C. albicans, tolerance to azoles involves the activation of efflux pumps and/or increased ergosterol synthesis.

Aims and method We explored sociodemographic and clinical factors associated with obtaining employment for people with severe mental illness. Standardised validated interviews and questionnaires were administered to participants who had been recruited into a randomised controlled trial of supported employment. RESULTS: Older age and diagnosis of schizophrenia were found to be independent predictors of unemployment in the previous year. Other factors of unemployment such as ethnicity and educational level were not associated with obtaining employment. Clinical implications Older people and those with a diagnosis of schizophrenia may need additional targeted help in obtaining employment if they are to be helped to meet their vocational aims. Further research is needed to determine how this can be done most effectively.

We illustrate the use of quantitative proteomics, namely isotope-coded affinity tag labelling and tandem mass spectrometry, to assess the targets and effects of the blockade of matrix metalloproteinases by an inhibitor drug in a breast cancer cell culture system. Treatment of MT1-MMP-transfected MDA-MB-231 cells with AG3340 (Prinomastat) directly affected the processing a multitude of matrix metalloproteinase substrates, and indirectly altered the expression of an array of other proteins with diverse functions. Therefore, broad spectrum blockade of MMPs has wide-ranging biological consequences. In this human breast cancer cell line, secreted substrates accumulated uncleaved in the conditioned medium and plasma membrane protein substrates were retained on the cell surface, due to reduced processing and shedding of these proteins (cell surface receptors, growth factors and bioactive molecules) to the medium in the presence of the matrix metalloproteinase inhibitor. Hence, proteomic investigation of drug-perturbed cellular proteomes can identify new protease substrates and at the same time provides valuable information for target validation, drug efficacy and potential side effects prior to commitment to clinical trials.

The amount of water absorbed following a defined soaking period has been studied in natto soybean [Glycine max(L.) Merr.], but there are no reports of studies of the rate or rapidity of water uptake. This study was conducted to examine the suitability of several water uptake parameters, which define the speed and amount of water absorbed, for analysis of variance and to determine the extent of genotype, environment, and genotype × environment interaction effects on water uptake parameters. Two larger‐seeded checks and 14 natto lines were grown at six locations in 1996 and 1997. Water uptake observations were taken at 0, 1, 3, 6, and 24.5 h using seed from individual plots. The exponential rise to a maximum equation, Y= a[1 − exp(−bX)], was fitted for each plot. The parameters aat 16 h (a16) and b, best fit the assumptions for analysis of variance. Genotype, year × location, genotype × year, and genotype × location × year effects were significant for these parameters. Location effects were significant for a16 but not for bYear and genotype × location effects were not significant. In this study, genotype × environment effects were relatively unimportant, while the main effect of genotype was more important. The bparameter provides additional information compared with the use of a16 alone. Heritability estimates for water uptake parameters (a16, H= 0.36 ± 0.16; b, H= 0.42 ± 0.46) were low to moderate on a plot basis. It seems possible to select for both rapid and high final water uptake in natto soybean.

A risk related Value of Spend for Saving a Statistical Life (VSSSL) is proposed for cost-benefit studies across the power generation sector, and the nuclear industry in particular. An upper bound on VSSSL is set based on the UK government standard of around £1M or, in particular circumstances, £2M and the observation that excessive spend (probably of the order of more than £5M per statistical life) will cost lives. Above a risk of 10-3a-1it is assumed that VSSSL approaches a value around £2M (broad range £1M to £5M). At risks around 10-6a-1it is proposed that an appropriate VSSSL lies at £0.5M (range £0.25M to £1M). Where risks to the individual fall to the order of 10-9a-1, or less, a low residual VSSSL of £0.01M is applied. A practical example is explored with respect to radiological protection where a total collective dose determination is disaggregated to resolve broad bands of individual exposure, and hence risk. Where collective doses are dominated by individual doses no more than a few μSv, the detriment arising from a manSv can be valued at about £15k to £60k, which can have a major effect on cost-benefit approaches to spend decisions.

Potatoes are an important cash crop for small-scale producers worldwide. The move away from subsistence to commercialized farming, combined with the rapid growth in demand for processed agricultural products in developing countries, implies that small-scale farmers and researchers alike must begin to respond to these market changes and consider post-harvest treatment as a critical aspect of the potato farming system. This paper presents and assesses a low cost potato-grading machine that was designed explicitly to enable small-scale potato growers to sort tubers by size for supply to commercial processors. The results of ten experiments reveal that the machine achieves an accuracy of sort similar to commercially available graders. The machine, which uses parallel conical rollers, has the capacity to grade different tuber shapes and to adjust sorting classes, making it suitable for locations with high potato diversity. Its relatively low cost suggests that an improved and adapted version of this machine might enhance market integration of small-scale potato producers not only in Peru, but in other developing countries as well.

Hectic, fast-paced, high-stress, and fatigued. Does this describe your life? Concerns about stress and fatigue underlie many visits to practitioners and health food stores, often leading to the question, 'What can I take to have more energy?' or maybe more to the point, 'Why am I so tired?' [ABSTRACT FROM AUTHOR]

BACKGROUND/AIM: In childhood an appropriate response to GH treatment is achieved by titration of growth response against dose administered, with careful observation for side-effects. In order to evaluate the potential use of IGF monitoring in children treated with GH, a cross-sectional study has been carried in 215 children and adolescents (134 with GH deficiency (GHD), 54 with Turner syndrome (TS) and 27 with non-GHD growth disorders) treated with GH for 0.2-13.7 years. METHODS: IGF-I and IGF-binding protein-3 (IGFBP-3) were measured in ELISAs, using dried capillary blood collected onto filter papers. Results were expressed as the mean S.D. range (SDS). Values of either analyte < -2 or > +2 SDS were considered abnormal. RESULTS: IGF-I and IGFBP-3 SDS were higher in the TS and non-GHD groups (mean +0.01 and +0.1 respectively) than in those with GHD (mean value -0.6). Nineteen per cent of the IGF-I values (13% low, 6% high) and 12% of IGFBP-3 values were abnormal (10% low, 2% high). Abnormalities, either low or high, were most common in the GHD group. There was a weak but significant relationship between change in height SDS over the Year up to the time of sampling in the whole group and IGF-I SDS. Satisfactory growth performance (+0.5>change in height SDS> -0.5) was found in those with high (7.2%), normal (60%) and low (9.3%) IGF-I levels. Overall, it was estimated that 26% of the tests would indicate that an adjustment to GH dose (up in 18% and down in 8%) could be considered. CONCLUSIONS: From this cross-sectional study of IGF monitoring across a broad range of diagnoses and ages, it can be concluded that the majority of children on GH have normal levels of IGF-I and IGFBP-3, but 26% of tests could suggest that a change of GH dose should be considered. Regular monitoring of IGF-I and IGFBP-3 should be considered in any child on GH treatment.

BACKGROUND/AIM: In childhood an appropriate response to GH treatment is achieved by titration of growth response against dose administered, with careful observation for side-effects. In order to evaluate the potential use of IGF monitoring in children treated with GH, a cross-sectional study has been carried in 215 children and adolescents (134 with GH deficiency (GHD), 54 with Turner syndrome (TS) and 27 with non-GHD growth disorders) treated with GH for 0.2-13.7 years. METHODS: IGF-I and IGF-binding protein-3 (IGFBP-3) were measured in ELISAs, using dried capillary blood collected onto filter papers. Results were expressed as the mean S.D. range (SDS). Values of either analyte < -2 or > +2 SDS were considered abnormal. RESULTS: IGF-I and IGFBP-3 SDS were higher in the TS and non-GHD groups (mean +0.01 and +0.1 respectively) than in those with GHD (mean value -0.6). Nineteen per cent of the IGF-I values (13% low, 6% high) and 12% of IGFBP-3 values were abnormal (10% low, 2% high). Abnormalities, either low or high, were most common in the GHD group. There was a weak but significant relationship between change in height SDS over the Year up to the time of sampling in the whole group and IGF-I SDS. Satisfactory growth performance (+0.5>change in height SDS> -0.5) was found in those with high (7.2%), normal (60%) and low (9.3%) IGF-I levels. Overall, it was estimated that 26% of the tests would indicate that an adjustment to GH dose (up in 18% and down in 8%) could be considered. CONCLUSIONS: From this cross-sectional study of IGF monitoring across a broad range of diagnoses and ages, it can be concluded that the majority of children on GH have normal levels of IGF-I and IGFBP-3, but 26% of tests could suggest that a change of GH dose should be considered. Regular monitoring of IGF-I and IGFBP-3 should be considered in any child on GH treatment.

Of all the aspects of nuclear power in the UK, none is so contentious or so pivotal as the issue of nuclear waste and its management. While there is no immediate cause for alarm, a huge amount of improvement is needed if the UK's custody of its radioactive waste is to become a programmed and prosecuted success. This paper discusses the UK radioactive waste inventory, UK radioactive waste policy, and radioactive waste storage.

To investigate the effect of different environments on maize resistance to gibberella ear rot, disease symptoms, deoxynivalenol (DON) concentration, and grain yield were measured in three maize (Zea mays L.) inbred lines and five hybrids, from 1994 to1996, at six locations in eastern Canada. At each location, all genotypes were inoculated with a three-isolate macroconidial mix of Fusarium graminearum Schwabe [teleomorph: Gibberella zeae (Schw.) Petch] using a kernel-stab inoculation technique. Results show that year to year variation is more important than variation associated with multiple locations in testing for genotypic resistance to gibberella ear rot, according to disease symptoms and DON content. Severe ear rot and higher DON concentrations among genotypes prevailed in 1994, when environmental conditions during the growing season were more favourable for ear rot development. Regression models indicated that higher ear rot severity and DON concentration were associated with an increase in the total number of days from July to September with relative humidity equal to or greater than 80%. In a favourable environment, moderately severe ear rot symptoms gave up to a 48% yield reduction in susceptible maize hybrids.Afin d'etudier les effets des variations environnementales sur la resistance du mais (Zea mays L.) a la fusariose de l'epi, des mesures de la severite des symptomes de la maladie, de la teneur en deoxynivalenol (DON) et du rendement en grain ont ete prises sur trois lignees de mais et cinq hybrides commerciaux, de 1994 a 1996, sur 6 sites de l'est du Canada. A chaque site, les epis de chaque genotype ont ete inocules avec la technique du poincon a pointes trempees dans une solution macroconidienne constituee de trois isolats du Fusarium graminearum Schwabe [teleomorph: Gibberella zeae (Schw.) Petch]. Les resultats demontrent que l'effet des annees est plus important que l'effet des divers sites d'essais dans l'evaluation de la resistance a la fusariose de l'epi selon les symptomes de la maladie et la teneur en DON. Des symptomes plus severes de la maladie et une teneur plus elevee en DON ont ete observes en 1994, une annee plus favorable au developpement de la fusariose de l'epi. Une regression lineaire a permis d'etablir une association entre la severite des symptomes de la maladie et la teneur en DON avec un accroissement du nombre de jours avec une humidite relative egale ou superieure a 80% durant la periode de juillet a septembre. Dans un environnement favorable, la presence moderee de symptomes de la maladie est associee a une reduction de rendement de l'ordre de 48% sur des hybrides de mais susceptibles.

Both 3-(hydroxymethyl)-5-methylsalicylaldehyde and its acetonide condense in the presence of hydrogen chloride in ether to form macrocyclic S4-symmetric tetraacetal 2. The reaction is completely oligo- and stereoselective, forming only the tetramer and only the achiral (R,S,R,S)-stereoisomer. Acid-catalyzed equilibration studies and molecular mechanics calculations indicate that the stereoselectivity is thermodynamic in origin. In the crystal the saddle-shaped molecules of 2 form coaxial stacks reminiscent of the packing of Pringles potato chips.

The site of cleavage of the small coat protein of cowpea mosaic virus has been precisely mapped and the proteolysis has been shown to result in the loss of 24 amino acids from the carboxyl-terminus of the protein. A series of premature termination and deletion mutants was constructed to investigate the role or roles of these carboxyl-terminal amino acids in the viral replication cycle. Mutants containing premature termination codons at or downstream of the cleavage site were viable but reverted to wild-type after a single passage through cowpea plants, indicating that the carboxyl-terminal amino acids are important. Mutants with the equivalent deletions were genetically stable and shown to be debilitated with respect to virus accumulation. The specific infectivity of preparations of a deletion mutant (DM4) lacking all 24 amino acids was 6-fold less than that of a wild-type preparation. This was shown to be a result of DM4 preparations containing a much increased percentage (73%) of empty (RNA-free) particles, a finding that implicates the cleavable carboxyl-terminal residues in the packaging of the virion RNAs.

Residues 1-127 of human TIMP-2 (N-TIMP-2), comprising three of the disulfide-bonded loops of the TIMP-2 molecule, is a discrete protein domain that folds independently of the C-terminal domain. This domain has been shown to be necessary and sufficient for metalloproteinase inhibition and contains the major sites of interaction with the catalytic N-terminal domain of active matrix metalloproteinases (MMPs). Residues identified as being involved in the interaction with MMPs by NMR chemical shift perturbation studies and TIMP/MMP crystal structures have been altered by site-directed mutagenesis. We show, by measurement of association rates and apparent inhibition constants, that the specificity of these N-TIMP-2 mutants for a range of MMPs can be altered by single site mutations in either the TIMP "ridge" (Cys1-Cys3 and Ser68-Cys72) or the flexible AB loop (Ser31-Ile41). This work demonstrates that it is possible to engineer TIMPs with altered specificity and suggests that this form of protein engineering may be useful in the treatment of diseases such as arthritis and cancer where the selective inhibition of key MMPs is desirable.

We compared the association constants of tissue inhibitor of metalloproteinases (TIMP)-3 with various matrix metalloproteinases with those for TIMP-1 and TIMP-2 using a continuous assay. TIMP-3 behaved more like TIMP-2 than TIMP-1, showing rapid association with gelatinases A and B. Experiments with the N-terminal domain of gelatinase A, the isolated C-terminal domain, or an inactive progelatinase A mutant showed that the hemopexin domain of gelatinase A makes an important contribution to the interaction with TIMP-3. The exchange of portions of the gelatinase A hemopexin domain with that of stromelysin revealed that residues 568-631 of gelatinase A were required for rapid association with TIMP-3. The N-terminal domain of gelatinase B alone also showed slower association with TIMP-3, again implying significant C-domain interactions. The isolation of complexes between TIMP-3 and progelatinases A and B on gelatin-agarose demonstrated that TIMP-3 binds to both proenzymes. We analyzed the effect of various polyanions on the inhibitory activity of TIMP-3 in our soluble assay. The association rate was increased by dextran sulfate, heparin, and heparan sulfate, but not by dermatan sulfate or hyaluronic acid. Because TIMP-3 is sequestered in the extracellular matrix, the presence of certain heparan sulfate proteoglycans could enhance its inhibitory capacity.

Data were collected on 130 intact male lambs fed diets based on roughages supplemented with fish meal, soybean meal, or corn gluten-blood meal and slaughtered at 43 kg live weight. A nonsupplemented group served as a control. The lambs represented Romanov (R), Finnsheep (F), a new breed developed in Canada (DLS), Coopworth (C), and Suffolk (S), three first crosses of DLS with R, F, and Booroola Merino (B), and their backcrosses to DLS. Supplemented lambs consumed 16 to 22% less (P< .05) silage than control lambs. Average daily gains of lambs fed fish meal (226 g) and corn gluten-blood meal (217 g) were higher and feed conversion ratio (4.99 and 5.11) lower than that of lambs fed soybean meal (189 g and 5.48) or control (186 g and 5.76) diets (P< .05). The cost of feed per kilogram of gain or per kilogram of lean produced was similar in the four treatments but was between C$.23 and .65 cheaper in the protein-supplemented groups when the number of days to reach slaughter weight was considered. The effect of diet on carcass traits and meat quality were minimal. Meat of lambs fed the three protein supplements was less juicy than that of control lambs. With a few exceptions, most of the significant differences among genetic groups in growth, carcass, and sensory traits were mainly between prolific (R and F) and meat-type breeds (C, S, and DLS). Gain in weight was highest in S lambs (199 g/d), but F and R first crosses were the youngest at slaughter (196 and 198 d). The F lambs had higher dressing and kidney fat percentages than meat-type breeds. The DLS lambs had the largest longissimus muscle area (14.0 cm2), whereas C had the smallest (10.7 cm2). The B crosses had larger longissimus muscle area than R and F crosses. The R lambs had more lean and less fat in the 12th rib, whereas C lambs had the lowest lean and a high bone percentage. The toughest and the most tender roasts were those of R and B crossbred lambs, respectively. Roasts from F lambs had the most intense lamb flavor.

We have examined the complete longitudinal height velocity (HV) data of 135 (80 male and 55 female) chromosomally normal children from the edinburgh Longitudinal Growth Study who were measured six-monthly between age 3 years and the onset of the adolescent growth spurt. Individual HV curves appeared to consist of a regular series of accelerations and decelerations in a cyclical fashion. After excluding variations due to measurement error, and basing the analysis on the pattern of acceleration, we were able to identify a number of spurts of regular occurrence. The mid-childhood spurt was clearly identified at ages 7·0 in boys and 6·7 years in girls, and could be identified in all children except one girl. Other spurts were also apparent; a pre-school spurt at ages 4·8 and 4·6, a late-childhood spurt at ages 9·2 and 8·6, and in children with an average-to-late onset of puberty, a prepubertal spurt at ages 10·8 and 10·0 years in boys and girls respectively. Synchronization at peak HV was performed for each spurt as described by Shuttleworth (1937) for the adolescent growth spurt. The overall pattern of growth appeared to be cyclical with a mean peak interval of 2·2 years in boys and 2·1 years in girls, the cycles appearing to continue until interrupted by the onset of the adolescent growth spurt. Sitting height velocity (SHV) and leg length velocity (LLV) curves also showed a cyclical pattern, but each varied independently. The magnitude of the HV spurts in an individual was dependent on the synchrony between the phases of SHV and LLV spurts.The cyclical pattern of prepubertal growth with its rapid changes in HV should be taken into account when assessing the growth of any child and in the response to any treatment offered.

The complete biologically active human immunodeficiency virus type-1 (HIV-1) rev-response element (RRE) RNA is 351 nucleotides (nt) in length, and includes an extra 58 nt on the 5′ end and 59 nt on the 3′ end beyond the sites proposed in the original models for the RRE secondary structure. The extra sequences are able to form a duplex structure which extends Stem I. The presence of an elongated Stem I structure in the RRE RNA was confirmed by nuclease mapping experiments. Nuclease protection experiments have shown that rev binds to restricted regions of the RRE, including the high affinity site located at the base of Stem IIb and along the length of the Stem I region. The three large stem-loop structures which protrude from Stem I and Stem IIb (Stems IIc, III+IV + and V) remain accessible to nucleases even in the presence of a large excess of protein. Gel-retardation experiments show that the truncations of Stem I reduced the total number of rev molecules that can bind co-operatively and with high affinity to the RRE RNA. To test whether the elongated Stem I structure is required for maximal rev activity, a series of truncations which progressively reduced the length of Stem I was introduced into an HIV-1 derived reporter plasmid. In the presence of rev and a functional RRE, there is an increase in the levels of gagand envmRNA in the cytoplasm and a decrease in levels of tatand revmRNAs. Each of the truncations in Stem I reduced the rev responses, with the longest truncations producing the greatest losses of activity. The data suggest that the RRE acts as "molecular rheostat" designed to detect rev levels during the early stages of the HIV growth cycle.

Apart from the Sturm theorem, some of the most useful comparison theorems in second-order ordinary linear differential equations are the Taam-Hille-Wintner theorems. In this note we obtain an extension of these theorems to more general nonlinear equations and incidentially settle an open question for the linear case.

A three dimensional system of ordinary differential equations modeling two predators competing for a renewable resource is analyzed and a periodic solution established in the open octant by a bifurcation from a two dimensional limit cycle. The basis equations are similar to those of the chemostat. This result confirms numerical evidence from [7], partially answering a question raised there.

Forty-eight crossbred beef steer calves, initial live weight of 260 kg, were used to examine production responses when grass silage was supplemented with fish meal (FM) or soybean meal (SBM) during a 210-d feeding period. The silage was available on an ad libitum basis either alone or supplemented with 100, 225, 350, or 500 g of FM or 600 g of SBM/d. Increasing levels of FM resulted in a linear increase in live weight gain (P< .001) and gain:feed ratio (P< .001). The FM supplementation had no effect (P= .79) on silage DM intake. The FM supplement increased plasma albumin concentration (P< .05) but did not affect plasma glucose (P> .20) The steers were shipped to market when they had 8 mm of fat over the longissimus muscle as determined by ultrasound. Sensory evaluation of roasts from steers fed 0, 225, 350, or 500 g/d of FM indicated a positive linear (P< .01) increase in flavor and decrease in juiciness as FM level increased. There were no differences (P> .15) in live weight gain, intake, or gain:feed ratio between isonitrogenous supplements of FM and SBM. However, the additional gain resulting from SBM and FM indicated that, on a crude protein basis, SBM was approximately 80% as effective as FM in increasing live weight gain in steers fed grass silage.

The effects of supplementing gestation and lactation diets of gilts with different combinations of vitamin E at or above NRC recommended levels (22, 44, or 88 IU/kg during gestation and 55, 110, and 220 IU/kg during lactation) and types of fat (5% added tallow or fish oil or no added fat) on humoral and cellular immunity of gilts and their pigs were evaluated. With only two exceptions, total IgG, IgM, and IgA in colostrum, milk, and plasma of gilts and in plasma of their pigs did not show significant (P> .05) effects, and no interactions between vitamin E and fat supplementation were observed. Cellular immunity was measured as lymphocyte proliferation response to phytohemagglutinin (PHA), concanavalin A (Con A), purified protein derivative of Mycobacterium avium,keyhole limpet hemocyanin, Escherichia colilipopolysaccharide (LPS), and Salmonella typhimuriumLPS. Only the nonspecific mitogens, PHA and Con A, induced proliferation of gilt and pig lymphocytes. Fish oil supplementation in the gilts' diets resulted in lower (P< .01) postpartum PHA response in gilts and slower (P< .05) acquisition of PHA response in newborn pigs compared with groups with added tallow or no added fat. The vitamin E supplementation did not have a significant positive effect on either PHA or Con A response of the gilts. However, the rate of acquisition of PHA response and Con A response in newborn pigs was greater (P< .05) for groups supplemented with 110 and 220 IU/kg of vitamin E than for the group supplemented with 55 IU/kg vitamin E.

Over a 2-yr period, the carcass characteristics and sensory properties of rib roasts from 44 bulls and 43 steers of Hereford × Shorthorn breeding raised in the Great Claybelt of Northern Ontario were studied. These animals were fed, from weaning (6 mo) to slaughter, diets of direct-cut grass silage (formic acid treated) supplemented with .0, .45, .9 or 1.35 kg high-moisture barley (DM)/100 kg live weight (propionic acid treated). Each animal was slaughtered at a minimum carcass finish of 8 mm of fat over the M. longissimus between the 11th and 12th ribs as measured by ultrasound. The average carcass grade for animals fed the all-silage diet or the silage diets supplemented with high moisture-barley was Canada A1/A2. The percentages of wholesale plate and brisket increased linearly (P⩽ .05) with increasing supplementation of high-moisture barley. Tenderness of rib roasts was not influenced (P>.05) by the different diets, whereas differences due to diet (P⩽.05) were observed for juiciness and flavor. However, because of the magnitude of these differences, it was concluded that the sensory properties of the rib roasts from animals fed the various diets were, for all intent, comparable. Both bulls and steers produced Canada A1/A2 carcasses. Bull carcasses contained a higher (P⩽.01) percentage of boneless, trimmed chuck and sirloin, and boneless, trimmed meat than steer carcasses. Sensory panel scores for juiciness, flavor and tenderness of rib roasts were not different (P>.05) between bulls and steers.

Research on the determinants of housing expenditure in Australia is limited by inadequate treatment of the distinction between three types of households: home renters, homeowners in the process of purchase, and homeowners who own outright. In this paper the authors use published and unpublished cross-sectional data from 1966–1968 and 1975–1976 to demonstrate the importance of the various determinants of housing across the three household types and, for the first time, to compare the characteristics at two points in time almost a decade apart. It was found that the influence of sociodemographic variables such as age, employment status, and household size was statistically significant, and that their influence varied considerably across the three household types. Detailed analysis has shown that income elasticity estimates of demand for housing were all found to be invariant over time, to be substantially less than 1.0 and to differ markedly between tenure type, with home renters having the lowest values (0.46–0.49), outright homeowners the highest (0.69), and mortgaged homeowners in between (0.53–0.59).

Transcription of the Saccharomyces cerevisiae metallothionein gene CUP1 is induced in response to high environmental levels of copper. Induction requires the ACE1 gene product, which binds to specific sites in the promoter region of the CUP1 gene. In this study, we found that deleting the entire coding sequence of the ACE1 gene resulted in a decrease in basal-level transcription of CUP1 to low but detectable levels and conferred a copper-sensitive phenotype to the cells. We have isolated a gene, designated ACE2, which when present on a high-copy-number plasmid suppresses the copper-sensitive phenotype of an ace1-deletion strain. The presence of multiple copies of the ACE2 gene enhanced expression of an unlinked CUP1-lacZ fusion integrated in the yeast genome and resulted in an increase in the steady-state levels of CUP1 mRNA in an ace1-deletion background. A large deletion of the coding region of the genomic copy of ACE2 resulted in a decrease in steady-state levels of CUP1 mRNA, indicating that ACE2 plays a role in regulating basal-level expression of CUP1. The ACE2 open reading frame encodes a polypeptide of 770 amino acids, with putative zinc finger structures near the carboxyl terminus. This protein is 37% identical to the SWI5 gene product, an activator of HO gene transcription in S. cerevisiae, suggesting that ACE2 and SWI5 may have functional similarities.

It has been proposed that the cell-mediated activation of progelatinase A requires binding of the C-terminal domain of the proenzyme to a membrane-associated complex of the membrane type matrix metalloproteinase MT1-MMP and TIMP-2. Subsequent sequential proteolysis of the propeptide by MT1-MMP and gelatinase A is thought to generate the active form of gelatinase A. We have prepared the proform of the catalytic domain of the MT1-MMP and demonstrated that this may be activated in vitro by trypsin proteolysis to yield a functional proteinase capable of cleaving typical metalloproteinase peptide substrates, gelatin and casein. The active catalytic domain of MT1-MMP was also shown to activate progelatinase A to a fully active form. Using the inactive mutant pro-E375A gelatinase A, we dissected the propeptide processing events that occur. MT1-MMP cleaves the propeptide at the sequence Asn37-Leu38 only. Further cleavage of the mutant enzyme propeptide at Asn80-Tyr81, equivalent to that of the active wild type gelatinase A, could only be effected by addition of gelatinase A to the system. TIMP-1 was essentially unable to prevent MT1-MMP processing of wild type or E375A progelatinase A, whereas TIMP-2 and TIMP-3 were good inhibitors of these events. Analysis of the rate of binding of TIMPs to the catalytic domain of MT1-MMP using kinetic methods showed that TIMP-1 is an extremely poor inhibitor of MT1-MMP. In comparison, TIMP-2 and TIMP-3 are excellent inhibitors, binding more rapidly to the catalytic domain of MT1-MMP than to the catalytic domain of gelatinase A. These data demonstrate the basic mechanism of MT1-MMP action on progelatinase A and the reason for the lack of inhibition by TIMP-1 previously demonstrated in cell-based activation studies.

Abstract: Some diploid strains of Saccharomyces cerevisiae can grow both as a spherical yeast form and as a filamentous pseudohyphal form. Most yeasts capable of forming pseudohyphae possess a functional FLO8 gene. We show that disrupting the ACE2 transcription factor results in the production of pseudohyphae in a flo8-1 background. Disrupting the CTS1 (chitinase) gene also produces pseudohyphal growth in this background, but at a reduced level. Invasion of solid media by haploid and diploid cells is increased in ACE2 disruptions, but the diploids adhere poorly to the agar. Σ1278b-derived strains, which generally produce pseudohyphae, have about 30-fold lower chitinase activity than other strains.

The 1-set contractions and strict set contractions of a bounded, closed, convex subset C of a Banach space X are generalizations of the nonexpansive mappings and the Banach contractions of C, defined in terms of the measure of noncompactness of bounded subsets of X. Vidossich has shown that ``almost all'' nonexpansive mappings of C into itself have fixed points. In this note we establish a similar generic result for the 1-set contractions of C.

The ground state masses of thirty-nine neutronrich nuclei from51Ca to72Ni have been measured using the Time-of-Flight Isochronous (TOFI) spectrometer. Eight of these masses have been measured for the first time and thirty-one are remeasurements of neutron-rich nuclei previously reported. Good agreement between these results and a previous TOFI experiment was observed except for the most neutron-rich isotopes of vanadium through iron with the present results being more bound and in better agreement with theory. The low binding energy of68Ni, as indicated by an unreasonably low two-neutron separation energy, suggests the presence of a high-lying, long-lived isomeric state in this nucleus.

Graft copolymers of acrylamide and yellow dextrin were prepared using cerium(IV) as initiator. The yellow dextrin had a very broad molecular weight distribution but was fractionated utilizing dialysis and ultrafiltration membranes. Initiator efficiencies were determined using size exclusion chromatography and were found to be between 2.4 and 34%. Initiator efficiency increased with acrylamide concentration at constant cerium (IV) and yellow dextrin concentrations, and decreased with increasing cerium(IV) concentration at constant acrylamide and yellow dextrin concentrations. Plots of acrylamide conversion and intrinsic viscosity vs initial acrylamide concentration at constant yellow dextrin and ceric ion concentrations showed a maximum at about 2.0 M.

The synthesis, characterization, and evaluation of bifunctional synthetic enzymes via alternating copolymerization was carried out. It was desired to obtain copolymers containing alternating placements of complementary functional groups to determine whether "cooperativity" between the groups (in the hydrolysis of ester substrates) would be greater than in the corresponding random copolymers containing the same functional groups. The bifunctional alternating copolymer, N-(β-vinyloxyethyl)imidazole-N-hydroxymaleimide, was synthesized and evaluated as a catalyst in the hydrolysis of p-nitrophenyl acetate. The effectiveness of this copolymer as an esterolysis catalyst was compared with imidazole and the homopolymer of N-hydroxymaleimide. Monomer syntheses, polymerization, and copolymer properties are also reported.

An electron spin resonance study of the intermediate radicals formed in the cyclopolymerization of certain nitrogen-containing monomers has been carried out. An initiation radical, both in N-(p-bromophenyl)dimethacrylamide (BrPhDMA) and sym-dimethacryloyldimethylhydrazine (DMMH), could be observed. The crystalline structure of DMMH is not known at present, but the comparison of the crystalline structure of BrPhDMA with that of N-methyldimethacrylamide suggests that the crystalline structure in these cyclization reactions is very important, In the glassy state of BrPhDMA, an anion radical of the methacryl group was detected as was the case in the glassy state of propyl- and benzyldimethacrylamides. It is significant that only the 5-membered cyclic radical was detected in the glassy state of BrPhDMA, because only the non-cyclic initiation radical was observed in irradiated crystalline BrPhDMA at -196°C, and only the 5-membered cyclic radical was detected in propyl- and benzyldimethacrylamide in both the crystalline and glassy states.