bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic diversity in Old Subterranean Clover (Trifolium subterraneum L.) Populations in Western Australia. I. Pastures sown initially to the Dwalganup strain
Authors: Rossiter RC , Collins WJ
Published: November 2004

Subterranean clover burrs were collected during summer from 28 sites, 10 of which were in the <500 mm annual rainfall zone. All sites had been sown to the Dwalganup strain, 30-50 years ago. Spaced plants were grown from seed from burr subsamples of each population. Several morphological characters, flowering dates, and oestrogenic isoflavones in late spring leaf samples were determined. At maturity, burr samples were collected from each plant, and the isozyme patterns in seeds were determined for eight enzyme systems using starch gel electrophoresis. Populations from the lower rainfall (< 500 mm) sites usually consisted of one or two strains - Dwalganup with or without Geraldton - and variant (or 'unknown') genotypes were very rare or absent. Populations from the higher rainfall (> 500 mm) sites, on the other hand, comprised about 50% of a few known strains - mostly Dwalganup and/or Dinninup - the remaining 50% consisting of numerous variant genotypes. Infrequent outcrossing between the Dwalganup and Mt Barker strains is the likely major source of this variation. Possible explanations for the lack of variant genotypes in the lower rainfall zone are discussed.
Quantitative determination of oxytetracycline in honey by cylinder plate microbioassay
Authors: Gordon L
Published: November 2004

A cyclinder plate microbioassay is described for the presumptive detection of oxytetracycline (OTC) in honey, using Bacillus cereus var. mycoidesas the test organism. The inhibition of this organism due to naturally occurring inhibitory substances (NOIS) in honey has been reduced to <0.09 8g/g OTC equivalents. In honey with low NOIS level, this procedure detected 0.04 8g OTC/g honey. Most of the NOIS effect in honey was due to its acidic pH. Confirmation of OTC was made using the OTC resistant organism, Staphylococcus epidermidis. The use of the Difco B. cereus spore suspension method proved to be more reproducible and more sensitive than the B. cereus var. mycoicles vegetative cell suspension method. The microbioassay detects OTC in honey with greater sensitivity than other methods presently used.
Differential response of wheat to retained crop stubbles. II. Other factors influencing allelopathic potential; intraspecific variation, soil type and stubble quantity
Authors: Purvis CE , Jones GPD
Published: November 2004

The allelopathic potential of the unweathered stubble of field-grown sorghum and sunflower was examined under controlled conditions in a series of glasshouse experiments. Wheat emergence was significantly inhibited in the presence of stubble from the eleven sorghum, and ten of the twelve sunflower cultivars tested. Inhibition of wheat emergence in the presence of sorghum stubbles ranged from 10 to 31%, and in the presence of sunflower stubbles from 4 to 33%, demonstrating a high degree of intraspecific variation in allelopathic potential. Many of the wheat seedlings emerging in stubble treatments exhibited an abnormal geotropic response. A threefold increase in stubble quantity, from 0.5 to 1.5% w/w soil, resulted in an approximate doubling of phytotoxicity. Wheat emergence was significantly reduced when stubble was incorporated into all three soils tested, with greater inhibition recorded in chocolate soil and a 50: 50 chocolate soi1:sand mixture than in sand. The choice of crop cultivar and the management of stubble quantity, especially in harvester trails, have important implications for the minimization of negative allelopathic effects in stubble retention systems.
Root growth and water uptake by wheat during drying of undisturbed and repacked soil in drainage lysimeters
Authors: Meyer WS , Tan CS , Barrs HD , Smith RCG
Published: November 2004

The dynamics of root development and water uptake in undisturbed and repacked clay soil were studied during increasing soil water deficit pre- and post-anthesis to find how root distribution, soil type and plant development affect plant available water (PAW). Volumetric water fraction was measured with a neutron probe, while root distribution was measured non-destructively using a series of horizontal perspex observation tubes. Soil modification affected the downward root growth which changed little over time for undisturbed (U) soil (6.7-13.6 mm/d) compared with the repacked (R) soil (7.5-42.9 mm). In the well-watered treatments root distribution was mostly above the 0.55 m depth in U soil, while there was a reasonably uniform vertical distribution in R soil. The rate of root growth during post-anthesis drying was 61% of that during pre-anthesis drying. The specific root water uptake rate (vol./unit root length/time) was linearly related to the relative root growth rate, indicating the importance of root growth in supplying water during soil drying. Estimated PAW values reflected effects of soil hydraulic properties, root distribution and a propensity to grow new roots during soil drying. Differences in grain yield between treatments were thought to result from the effects of different root distributions and the propensity to grow roots during soil drying.
Immunization against somatotropin release inhibiting factor increases milk yield in ewes
Authors: Sun YX , Sinclair SE , Wynn PC , McDowell GH
Published: November 2004

Immunization of cross-bred ewes against somatotropin release inhibiting factor significantly increased (P < 0.01) milk yields, relative to yields of similar non-immunized (control) ewes, without affecting milk composition. Feed intakes of immunized ewes tended (P> 0.10) to be lower than those of control ewes and the efficiency of utilization of feed for milk production and digestibility of dry matter were significantly increased (P<0.10) by immunization. No effects of immunization were measured for plasma hormones and metabolites. It appears that the increase in milk production in response to immunization was the result of an increase in the supply of nutrients for milk production caused by a modification of gut function.
Corrigendum - Factors which affects the growth of grain legumes on a solonized brown soil. I. Genotypic responses to soil physical factors
Authors: Atwell BJ
Published: November 2004

Lupins (Lupinus angustifolius cvv. Yandee and 75A-258 and L. pilosus cv. P. 20957) and pea (Pisum sativum cv. Dundale) were grown in the field for 43 days on a solonized brown soil. Shoots of L. pilosus and peas grew most rapidly, while L. angustifolius cv. 75A-258 developed a relatively large root system. L. angustifolius cv. Yandee, a commercial lupin cultivar, was poorly adapted; shoot growth was restricted and roots ceased growing 36 days after sowing. The soil factors responsible for these widely differing responses were investigated. Once primary roots of L. angustifolius were 20-30 cm deep, root extension was slow or arrested. Indeed, primary root apices of Yandee were often necrotic in the soil below 20 cm. In contrast, roots proliferated rapidly in the surface 20 cm of the soil, particularly in 7SA-258, suggesting that factors in the deeper soil layers restricted root growth most severely. The vigorous growth of lateral roots of 75A-258 was reflected in a 2.6 fold greater total root length than for Yandee 43 days after sowing. Soil physical properties were not considered a likely explanation for these observations; soil water status and porosity were always favourable for root growth and root sections indicated that no cortical degradation, typical of O2 deficient roots, had occurred. Penetrometer resistance and root tip osmotic pressures suggested that poor root growth could not be ascribed simply to soil mechanical properties. The results suggest, by inference, that soil chemical factors could underlie the phenotypic responses observed.
Influence of host diet on the concentrations of fatty acids in rumen bacteria from cattle
Authors: O'Kelly JC , Spiers WG
Published: November 2004

This study compared the effects of supplements (300 mL/day) of safflower oil (SO) on the long-chain fatty acid (LCFA) content and composition of rumen liquid-associated (LAB) and solid-associated bacteria (SAB) in two experiments: (1) Hereford steers fed lucerne hay (6 kg/day) and (2) Brahman steers fed low-quality hay (4 kg/day). Experiment 1: SO increased the concentrations of mono-unsaturated (MUFA) and polyunsaturated acids (PUFA) in bacteria without altering the concentrations of saturated acids (SFA). The concentrations of all classes of LCFA except PUFA were higher in SAB than in LAB. Variation in phospholidpid (PL) composition of bacteria in response to SO included lowered proportions of branched-chain (brFA) and odd-numbered acids. In steers fed hay alone, the neutral lipids (NL) of all bacteria consisted predominantly of SFA (90%). With SO supplement, SFA constituted 60% and trans-11 monoenoic acid 31% of NL. There were significant differences between LAB and SAB in the proportions of individual acids in PL and NL. Experiment 2: SO increased the concentrations of all classes of LCFA except brFA which were decreased. SO treatment decreased the proportions of all acids in NL, except 18: 0, 18 : 1 trans-1 1 and 18 : 2, which were increased. The results have demonstrated that the fatty acid content and composition of mixed rumen bacteria is dependent upon their nutrient supply.
Genetic variation in liveweight and ultrasonic fat depth in Australian Poll Dorset sheep
Authors: Atkins KD , Murray JI , Gilmour AR , Luff AL
Published: November 2004

Genetic and phenotypic variances and covariances were estimated for liveweight and ultrasonic fat depth in the Australian Poll Dorset. The data were obtained from the New South Wales Meatsheep Testing Service between 1983 and 1986, and involved 28 159 records from 50 stud flocks. A total of 681 sires were used to derive the half-sib genetic parameters. The data were further grouped according to average age at measurement, so that parameters were estimated for animals within age ranges of 4-6 months, 7-11 months and 12-16 months. Heritabilities for liveweight were between 0.21 and 0.31, with the highest value obtained in the oldest age group. Heritabilities for fat depth varied between 0.26 and 0.31, with the highest value again obtained in the oldest age group. Genetic correlations between liveweight and fat depth were about 0.4 except in 4-6-month-old animals where the estimate was about 0.7. The implications of these parameters to breed improvement programmes are discussed. In particular, the scope for genetic response in producing faster growing, leaner animals at a constant liveweight is highlighted. Information on sire-son generation intervals and apparently limited between-flock genetic variation is reported. The results indicate the need to improve the evaluation procedures for sires within the breed at both the between- and within-flock level.
Effect of cropping history on soil populations of Bipolaris sorokiniana and common root rot of wheat
Authors: Wildermuth GB , McNamara RB
Published: November 2004

Six winter and four summer crops, two pasture legumes and two pasture grasses, were grown in rotation with wheat in soil naturally colonized with Bipolaris sorokiniana. Soil populations of B. sorokiniana under the different rotations were measured at the beginning of winter and of summer between 1982 and 1986. Populations increased under wheat, barley and triticale, remained static under oats, safflower and chickpea, and declined under buffel grass, cocksfoot, lucerne, mung bean, snail medic, sorghum, sunflower and White French millet. Populations also declined under a fallow, and propagules of the fungus were still present after 4 years. Where populations had declined owing to cropping history, they were effectively restored to their previous levels after one wheat crop. Severity of common root rot in wheat caused by B. sorokiniana, was reduced from that occurring with continuous wheat when wheat was planted after safflower, sorghum, mung bean, snail medic, lucerne and buffel grass. Disease levels in wheat following barley, triticale, oats, chickpea, millet, sunflower, cocksfoot or a fallow were not significantly different from that of continuous wheat. When a second wheat crop was planted, severity of common root rot was high in all treatments, irrespective of the previous cropping history. The implications of these findings in developing control strategies for common root rot by crop rotation are discussed.
Feed utilization, energy expenditure and nitrogen metabolism in working female buffaloes (Bubalus bubalis)
Authors: Teleni E , Pieterson R , De'ath G
Published: November 2004

Four 36-months-old female buffaloes, with a mean liveweight of 345 kg, were used in a study designed to estimate the effect of work (3 h/day) on feed utilization, energy expenditure and nitrogen metabolism. The animals were studied under ambient temperatures and relative humidities ranging from 25.3 to 32.5'C and 45 to 82% respectively, and were fed rice straw (0.8% nitrogen) ad libitum, supplemented with cottonseed meal at 500 g head-1 day-1 to result in a dietary nitrogen content of 1.15%. Work did not affect the digestibility of the feed but tended to reduce (P=0.054) ad libitum intake of its organic matter. Rectal temperatures and respiration rates were increased during work from 37.7 to a peak of 40.8�C and from 40 to a peak of 130 counts/min respectively. The ratio of working : resting metabolic rate, as calculated from CO2 entry rates, was approximately 2.6. Estimates of energy expenditures from CO2 entry rates showed increases in the working animal by 2.3 to 2.7 times the resting values. Nitrogen balance was reduced in the working animal owing to increased catabolism of amino acids and the resultant increased excretion of urea via the urine. Urea entry rate was increased in the working animal, but the proportion of this that was estimated to be transferred to the digestive tract was not different from that in the non-working animal, although the amount transferred was greater in the working animal. It is suggested that increased muscular activity in the working animal would tend to reduce ad libitum intake of organic matter of a roughage such as rice straw, but could increase digestibility of organic matter possibly through reduction in the rate of passage of digesta and/or through increased amount of urea transferred to the rumen containing lower than an optimal level of ammonia. The increased catabolism of amino acids associated with increased muscular activity is likely to result in a reduced nitrogen balance due to the likely increased urea excretion via the urine. It is also suggested that CO2 entry rate could offer a reasonable estimate of energy expenditure in the resting and the working animal.
The effect of dwarfing genes in spring wheat in dry environments. I. Agronomic characteristics
Authors: Richards RA
Published: November 2004

Near-isogenic lines of wheat were used to investigate the possible yield penalty of dwarfing genes in rainfed environments. Field experiments were conducted over seven years in south-eastern Australia which were characterized by drought becoming progressively more intense as crop maturity approached. Isogenic sets for the Rht1 and Rht2 genes were chosen to cover a range of heights for the tall (rhtrht) lines, from 100 to 130 cm when grown in the absence of drought before anthesis. Rht1 or Rht2 reduced this height by about 23% whereas Rht1 and Rht2 together or Rht3 alone reduced this ceiling height by about 47%. Highest grain yields were achieved by lines with a height between 70 and 100 cm. Although major were usually required to achieve this optimum height, no specific advantage of the major dwarfing genes was found. Likewise, in tall and short isogenic populations, the short populations yielded more than the tall populations even though they all contained Rht1. The expression of the major dwarfing genes and their effect on agronomic characteristics varied depending on the genetic background but general trends were evident. Above-ground dry weight was reduced by 4.4% of the mean weight for each 10 cm reduction in height below 100 cm. Above 100 cm there was little change in above-ground dry weight. Harvest index decreased by 3.7% of the mean value for each 10 cm increase in height above 65 cm. When height was less than 65 cm, harvest index remained constant. Kernel number was more sensitive to variation in height than was kernel weight. In only one of the isogenic sets was there evidence for compensation between kernel number and kernel weight; in four sets, both kernel number and kernel weight matched variation in yield in a positive way.
Differences in flowering responses of wheat to temperature and photoperiod
Authors: Manupeerapan T , Davidson JL , Pearson CJ , Christian KR
Published: November 2004

Apex and ear development were studied in one spring wheat (Hartog) and five winter wheats (Rosella, Maris Templar, Maris Huntsman, Priboy and Krasnodar 39) subjected to vernalizing or non-vernalizing temperatures under either short or long photoperiods until ear initiation (double ridges), followed by either short or long photoperiods until ear emergence. Hartog produced ears in all treatments, and it initiated ears faster than winter varieties in all treatments. Four types of winter wheat were distinguished by their mandatory requirements for ear development. The only winter variety to reach ear emergence without vernalization was Maris Templar; short days were an effective substitute provided that long days were experienced after ear initiation. In Priboy, photoperiod was unimportant both before and after ear initiation. Maris Huntsman and Rosella required long photoperiods after initiation, whereas Krasnodar 39 required long days during vernalization. If these conditions were not met, either the shoot apexes died without producing a terminal spikelet or the ears died before emerging. Plants in all treatments which reached ear emergence proceeded normally to maturity. The suitability of the different types for particular regions is discussed. All varieties in all treatments initiated ears when the shoot apex reached a volume of about 0.13 mm3. Relative growth rates of the apex, related to thermal time, were constant during the vegetative phase; they determined the time to ear initiation and, through it, controlled the time of ear emergence. Differences between varieties in their basic vegetative period are attributed to differences in the relative growth rates of their vegetative apexes. These growth rates were much lower in winter wheats than in the spring variety, but increased sharply in them at or just before the first visible signs of initiation in those treatments which allowed normal development. Vernalization was not the cause of this accelerated growth. In winter wheats, vernalization promoted faster initiation of ears, and hence flowering, and the survival and normal development of initiated ears. It is suggested that vernalization acts by reducing the effectiveness of an inhibitor of cell division.
Yield improvement of oilseed rape (Brassica napus L.) in a low rainfall environment. I. Utilization of genes for early flowering in primary and secondary gene pools
Authors: Thurling N , Kaveeta R
Published: November 2004

The extent to which time to flowering of a Brassica napus commercial cultivar could be reduced through utilization of genes in its primary and secondary pools was examined with particular reference to yield improvement in lower rainfall environments. The B. napus breeding line RU2 and the B. campestris population Chinoli C42, which were used as sources of early flowering genes to be incorporated into the commercial B. napus cultivar Wesbrook, flowered significantly earlier than Wesbrook with or without vernalization and/or long days. In the cross of Wesbrook with RU2, the substantial variation in flowering time in the F2 was highly heritable (hn2 = 0.79), and some plants in the F2 and first backcross to Wesbrook flowered earlier than the early flowering parent RU2. Many lines flowering much earlier than Wesbrook were still obtained after two generations of recurrent backcrossing to Wesbrook and subsequent selfing without selection at any stage. Variation in flowering time among these lines primarily reflected differences in growth rate as measured by the rate of leaf node development. F2 plants derived from the cross between Wesbrook and the B. campestris population Chinoli C42 varied widely in chromosome number and flowering time, but there was no relationship between pre-anthesis development and chromosome number. Two generations of recurrent backcrossing to Wesbrook and subsequent selfing without selection at any stage produced a series of lines all having the normal B. napus chromosome complement. All these lines flowered significantly earlier than Wesbrook, and the earliest flowering line flowered at the same time as the early flowering B. campestris parent. The implications of these results are discussed with particular reference to developing agronomically superior B. napus cultivars closely adapted to lower rainfall environments in the Western Australian wheatbelt and elsewhere in southern Australia.
Identification of drought tolerance in early-maturing indeterminate soybeans (Glycine max (L.) Merr.)
Authors: Rose IA , McWhirter KS , Spurway RA
Published: November 2004

Drought escape through earliness is a potential strategy for the expansion of soybean (Glycine max (L.) Merr.) production into marginal rainfall areas that has not been fully evaluated. In this study, early-maturing (Maturity Groups II to IV), indeterminate inbred lines of soybeans were developed from six single cross populations and evaluated under naturally occurring terminal drought stress at a latitude normally associated with maturity adaptation corresponding to Groups V to VII. Parallel evaluation under a high yield irrigation regime provided the basis for evaluation of genotypic response to moisture stress. All lines were early enough to exhibit drought escape, but there was an additional response in some genotypes. While all genotypes showed premature senescence under drought stress some genotypes, in the WilliamsxCalland population, continued growth for significantly longer than the parents or the population average under the terminal drought stress. A stress index for maturity was devised to describe the degree of premature senescence, and this index was shown to be a heritable trait not correlated with maturity per se. It is concluded that these lines represent a previously unreported source of tolerance to drought stress and, when used in conjunction with early maturity drought escape, they provide an additional trait for improving soybean tolerance to moisture stress.
Differential tolerance of genotypes of Medicago truncatula to low pH
Authors: Bounejmate M , Robson AD
Published: November 2004

Growth and nodulation of five Moroccan ecotypes of Medicago truncatula Gaertn. Collected from soils of different pH, Medicago truncatula cv. Cyprus and Medicago murex Willd. cv. Zodiac, were compared in soil and solution at different pH values. The seven genotypes tested varied greatly in their ability to grow and nodulate on acid soils. Increasing soil pH from 4.5 to 5.4 increased the shoot dry weight of Cyprus and three M. truncatula ecotypes but not Zodiac and two M. truncatula ecotypes. Cultivar Cyprus, with a shoot dry weight at pH 4.5 only 58% of that at pH 5.4, was the most affected by acidity. Nodulation was the most sensitive step as nodule numbers decreased with increasing acidity for sensitive genotypes. Several genotypes were more able to nodulate at low pH than the commercial cultivar Cyprus. Acid tolerance was not restricted to genotypes occurring naturally in acid soils.
Fragile X mental retardation protein is necessary for neurotransmitter-activated protein translation at synapses
Authors: Weiler Ivan Jeanne , Spangler Chad C. , Klintsova Anna Y. , Grossman Aaron W. , Kim Soong Ho , Bertaina-Anglade Valerie , Khaliq Hooma , de Vries Froukje E. , Lambers Femke A. E. , Hatia Fatima , Base Christine K. , Greenough William T.
Published: November 2004

Fragile X mental retardation is caused by absence of the RNA-binding protein fragile X mental retardation protein (FMRP), encoded by the
FMR1
gene. There is increasing evidence that FMRP regulates transport and modulates translation of some mRNAs. We studied neurotransmitter-activated synaptic protein synthesis in
fmr1
-knockout mice. Synaptoneurosomes from knockout mice did not manifest accelerated polyribosome assembly or protein synthesis as it occurs in wild-type mice upon stimulation of group I metabotropic glutamate receptors. Direct activation of protein kinase C did not compensate in the knockout mouse, indicating that the FMRP-dependent step is further along the signaling pathway. Visual cortices of young knockout mice exhibited a lower proportion of dendritic spine synapses containing polyribosomes than did the cortices of wild-type mice, corroborating this finding
in vivo
. This deficit in rapid neurotransmitter-controlled local translation of specific proteins may contribute to morphological and functional abnormalities observed in patients with fragile X syndrome.
Transcriptional regulation of the 230‐kDa bullous pemphigoid antigen gene expression by interferon regulatory factor 1 and interferon regulatory factor 2 in normal human epidermal keratinocytes
Authors: Odanagi Maiko , Kikuchi Yasushi , Yamazaki Takehiko , Kaneko Takahide , Nakano Hajime , Tamai Katsuto , Vitto Joani , Hanada Katsumi
Published: November 2004

Abstract:  Interferon regulatory factors (IRFs) are a family of transcriptional factors induced by interferon‐γ (IFN‐γ). Recent studies have indicated that the deregulation of IRF system in keratinocytes is responsible, at least in part, for aberrant proliferation and the differentiation of the psoriatic epidermis. Previously, we reported that the expression of 230‐kDa bullous pemphigoid antigen (BPAG1) gene, which is strictly restricted to basal keratinocytes, is transcriptionally suppressed by IFN‐γ, but the contribution of IRFs in such suppression is still unclear. In this study, we investigated the role of IRFs in the regulation of BPAG1 gene expression. Computer analysis identified IRF1 and IRF2 consensus sequences between −135 and −123 on BPAG1 promoter region. Transient transfection studies with BPAG1 promoter‐luciferase reporter gene plasmids and IRF1 and IRF2 expression plasmids revealed that IRF1 and IRF2 directly down‐regulated BPAG1 gene transcription in cultured normal human epidermal keratinocytes. Several sets of gel retardation assays with the BPAG1–IRF binding sequence as a probe indicated that IRF1 and IRF2 could bind to the BPAG1–IRF sequence, but some other protein(s), which was induced by IFN‐γ stimulation and possessed binding activity to IRF consensus sequence, showed preferential binding to the BPAG1–IRF sequence. Our results suggest that IFN‐γ–IRF system is involved in BPAG1 gene regulation in type‐1 helper T‐cell inflammatory skin conditions, such as psoriasis vulgaris.
Hypocotyl expression and light downregulation of the soybean tubulin gene, tubB1
Authors: Tonoike Hiroshi , Han In‐Seob , Jongewaard Ian , Doyle Michele , Guiltinan Mark , Fosket Donald E.
Published: November 2004

The tubB1 β‐tubulin gene of Glycine max (previously named spβ1) is highly expressed only in rapidly elongating regions of etiolated seedling hypocotyls and this expression is strongly downregulated when the seedlings are exposed to light. Primer extension demonstrated that the gene was transcribed in these tissues and contained two sites of transcriptional Initiation. To determine the mechanism regulating tubB1 expression, a chimeric reporter gene was constructed by fusing 5′upstream regions of tubB1 to a promoterless (β‐glucuronidase (GUS) gene and these constructs were introduced into protoplasts by electroporation. Strong transient expression of the reporter gene was obtained after electroporation of chimeric constructs containing 1 kb of tubB1 5′upstream sequence into tobacco protoplasts. Deletion of the distal most 300 bp from the 5′sequence of tubB1 enhanced expression, suggesting the possibility of a negative transcriptional regulator in this region. Additional deletions of the 5 sequence reduced expression substantially. Constructs containing a tubB1 3′terminus were expressed at much lower levels than those containing a nopaline synthase (NOS) 3 terminus. The tubB1–GUS chimeric gene also was introduced into tobacco by Agrobacterium‐mediated Ti plasmid transformation and the organ‐specific expression pattern of the chimeric gene was determined in seedlings of the transgenic plants. Hypocotyls exhibited strong GUS activity when the seedlings were germinated in darkness, but lacked the GUS enzyme when the seedlings were germinated in the light. This result demonstrates that the cis‐acting elements within the first 2 kb of the translational start site of the tubB1 gene are sufficient for correct expression of the gene in etiolated, elongating hypocotyl tissues, and for the downregulation of this expression by light.
Stability of transgenes and presence of N6 methyladenine DNA in transformed wheat cells
Authors: Chen Dong Fang , Dale Philip J. , Heslop‐Harrison John S. , Snape John W. , Harwood Wendy , Bean Samantha , Mullineaux Philip M.
Published: November 2004

A number of stably transformed wheat cell lines were obtained using two different direct gene transfer techniques. When integration of the foreign genes was investigated in DNA samples taken at 10 months post‐selection, complicated profiles of transgene bands were observed in Southern blot analysis. Among these, a number of common bands were identified showing similar hybridization patterns between independently transformed cell lines. This type of hybridization pattern has been a common observation and is usually interpreted as concatameric rearrangement of integrated DNA. However, when integration was reinvestigated with DNA samples taken at 30 months postselection, the hybridization pattern changed and most of the common bands had disappeared. Further analysis using a set of methylation‐sensitive enzymes revealed that the DNA represented by the common bands was N6‐adenine methylated (m6A DNA), and there was even m6A DNA in some 30 month samples. Although the source of m6A DNA in the wheat cultures was not clearly established, the data indicate that transformation of an endophyte (e.g. a mycoplasma‐like organism) may have occurred at the same time as the transformation of wheat cells. The integration pattern of undermethylated transgenes in the transformed cells became simpler and clearer after treating the DNA preparations with Dpnl, which only cuts m6A DNA. The implications of these data for other methods of inoculating cereals with DNA are discussed.
Asparaginase gene expression is regulated in a complex spatial and temporal pattern in nitrogen‐sink tissues
Authors: Grant Murray , Bevan Michael W.
Published: November 2004

Asparagine is an important nitrogen transport compound in higher plants. Mobilized asparagine is deamidated by the enzyme asparaginase to aspartate and ammonia, which are major sources of organic nitrogen for plant growth and development. Little is known about the role of asparagine catabolism during plant development as the enzyme is difficult to assay, although it is known that asparaginase activity is located in tissues undergoing rapid growth and development, particularly in young leaves and developing seeds. In tobacco plants containing an asparaginase‐GUS gene fusion, GUS expression was specifically located in young developing tissues such as the apical meristem and expanding leaves. In mature plants, GUS activity was found predominantly in various tissues of the developing seed. In lupin, where up to 80% of the fixed nitrogen is exported as asparagine to the developing seed, GUS activity was also located in developing tissues such as the apical meristem, and in specific tissue types in the developing seed previously shown to contain asparaginase activity. All of the tissues in which asparaginase expression occurred have previously been shown to contain localized high levels of asparagine. This study therefore demonstrates an important role for transcriptional control of an asparaginase gene in regulating asparaginase levels in N‐sink tissues.
Phosphatase antagonist okadaic acid inhibits steady‐state K+ currents in guard cells of Vicia faba
Authors: Thiel Gerhard , Blatt Michael R.
Published: November 2004

The effects of protein phosphatase inhibitors on steady‐state K+ currents in the plasma membrane of Vicia faba guard cells were studied. Cells were impaled with double barrelled electrodes to monitor membrane voltage and K+ currents under voltage clamp. Okadaic acid (OA) (1 μM), a specific inhibitor of phosphatase 1 and 2A activity, blocks inward (lK+(in)) and outward (lK+(out)) rectifying K+ channels. Both currents decreased in parallel with a sigmoidal time course with 50% inhibition at about 8 min. With 0.2 μM OA inhibition became slower and more variable (4–34 min). Inhibition did not recover by washing cells ≤ 20 min in OA‐free solution. In five out of seven cells OA also induced a rise in the background conductance, which lagged behind the inhibition of K+ current. Both decaying lK*(out) and rising leak conductance caused a depolarization. OA‐induced inhibition of lK+(in) and lK+(out) was without a significant effect on the kinetics of voltage‐dependent current activation and deactivation. In an alternative approach, guard cells were loaded from the voltage recording pipette with the non‐specific phosphatase inhibitor naphthylphosphate. After an impalement of some minutes lK+(in) and lK+(out) were small or undetectable. In conclusion inward and outward K+ channels in guard cells have a common voltage‐independent mode of control which is sensitive to phosphatase inhibitors. The known specificity of OA points to a mode of action in which a net increase of protein phosphorylation through inhibition of phosphatase 1 and/or 2A activity blocks conductance of both, lK+(in) and l(out)
Simulating in‐plane fatigue damage in woven glass fibre‐reinforced composites subject to fully reversed cyclic loading
Authors: VAN PAEPEGEM W. , DEGRIECK J.
Published: November 2004

The interest in using fibre‐reinforced composites in structural components is increasing. Some of these structural composites, such as wind turbine blades, aircraft components and torsion shafts are subject to fatigue loadings. It is widely accepted that fully reversed cyclic loading is the most adverse loading for fibre‐reinforced composites, but the modelling of the material behaviour under this loading condition is very difficult. In this paper, a damage model is presented for woven glass fibre‐reinforced composites subject to fully reversed cyclic loading. First fatigue experiments have been conducted in displacement‐controlled fully reversed bending and the stiffness degradation and damage patterns have been observed. Based on these experimental data, a damage model has been developed, which includes the in‐plane stress components and the degradation of the in‐plane elastic properties. The model has been implemented in a commercial finite‐element code and simulation of the successive stages in the fatigue life has been performed. The model has been validated for a plain woven glass fabric reinforced composite and simulated stiffness degradation, damage growth and damage distribution have been compared with experimental data.
Proteasome inhibitors suppress formation of polyglutamine‐induced nuclear inclusions in cultured postmitotic neurons
Authors: Kim Woo‐Yang , Horbinski Craig , Sigurdson Wade , Higgins Dennis
Published: November 2004

At least nine neurodegenerative disorders are caused by expansion of polyglutamine repeats in various genes. This expansion induces the formation of nuclear inclusions (NI) within various cell types. In this study, we developed a model for polyglutamine diseases using primary cultures of sympathetic neurons from the superior cervical ganglia of prenatal rat pups. Transfection with a plasmid encoding 127 glutamine repeats causes NI to develop in ∼70% of the sympathetic neurons within 6 days. In addition, it causes somatic atrophy and inhibits dendritic growth. The NIs contain ubiquitinated proteins and sequester the molecular chaperone heat shock protein 70 (Hsp70). We found that two specific proteasome inhibitors, lactacystin and CEP1612, suppress thezformation of polyglutamine‐induced NI. In addition, lactacystin treatment induced the removal of preexisting NI. Western blotting and immunocytochemistry revealed that lactacystin and CEP1612 strongly induce the expression of Hsp70, whereas less specific proteasome inhibitor such as N‐acetyl‐Leu‐Leu‐Norleucinal does not. Coexpression of 127 glutamines with a plasmid encoding wild‐type Hsp70 gene resulted in a marked reduction of the percentage of neurons containing NI. In addition, transfection with plasmids encoding mutant Hsp70 blocked the effects of lactacystin. These findings further implicate Hsp70 as a neuroprotective molecule and they suggest the potential utility of certain proteasome inhibitors in the treatment of polyglutamine diseases.
Identification of regulatory cis‐acting elements for alternative splicing of presenilin 2 exon 5 under hypoxic stress conditions
Authors: Higashide Satoshi , Morikawa Keisuke , Okumura Masayo , Kondo Shinichi , Ogata Maiko , Murakami Tomohiko , Yamashita Akinori , Kanemoto Soshi , Manabe Takayuki , Imaizumi Kazunori
Published: November 2004

An alternatively spliced form of the presenilin 2 (PS2) gene lacking exon 5 (PS2V) was found in human brains with sporadic Alzheimer's disease. PS2V was induced by hypoxic stress in human neuroblastoma SK‐N‐SH cells, indicating that hypoxic stress affects the splicing machineries for PS2 exon 5. Here, we identified the critical cis‐acting element (sec 2) on the PS2 pre‐mRNA responsible for the aberrant splicing of PS2 exon 5 under hypoxic stress conditions. The element was composed of 23 nucleotides in exon 5 and RNA structural analyses showed a stem‐loop structure in this sequence. Treatment with an antisense oligonucleotide directed toward the cis‐acting element caused an increase in exon 5 inclusion. These results indicate that the sec 2 identified in this study is a novel regulatory element for exon 5 splicing under stress conditions and that trans‐acting factors could specifically bind to the element to skip exon 5 of PS2.
Opposite regulation of the mitochondrial apoptotic pathway by C2‐ceramide and PACAP through a MAP‐kinase‐dependent mechanism in cerebellar granule cells
Authors: Falluel‐Morel Anthony , Aubert Nicolas , Vaudry David , Basille Magali , Fontaine Marc , Fournier Alain , Vaudry Hubert , Gonzalez Bruno J.
Published: November 2004

The sphingomyelin‐derived messenger ceramides provoke neuronal apoptosis through caspase‐3 activation, while the neuropeptide pituitary adenylate cyclase‐activating polypeptide (PACAP) promotes neuronal survival and inhibits caspase‐3 activity. However, the mechanisms leading to the opposite regulation of caspase‐3 by C2‐ceramide and PACAP are currently unknown. Here, we show that PACAP prevents C2‐ceramide‐induced inhibition of mitochondrial potential and C2‐ceramide‐evoked cytochrome c release. C2‐ceramide stimulated Bax expression, but had no effect on Bcl‐2, while PACAP abrogated the action of C2‐ceramide on Bax and stimulated Bcl‐2 expression. The effects of C2‐ceramide and PACAP on Bax and Bcl‐2 were blocked, respectively, by the JNK inhibitor L‐JNKI1 and the MEK inhibitor U0126. L‐JNKI1 prevented the alteration of mitochondria induced by C2‐ceramide while U0126 suppressed the protective effect of PACAP against the deleterious action of C2‐ceramide on mitochondrial potential. Moreover, L‐JNKI1 inhibited the stimulatory effect of C2‐ceramide on caspase‐9 and ‐3 and prevented C2‐ceramide‐induced cell death. U0126 blocked PACAP‐induced Bcl‐2 expression, abrogated the inhibitory effect of PACAP on ceramide‐induced caspase‐9 activity, and promoted granule cell death. The present study reveals that C2‐ceramide and PACAP exert opposite effects on Bax and Bcl‐2 through, respectively, JNK‐ and ERK‐dependent mechanisms. These data indicate that the mitochondrial pathway plays a pivotal role in the pro‐ and anti‐apoptotic effects of C2‐ceramide and PACAP.
Lower All‐Cause, Cardiovascular, and Cancer Mortality in Centenarians' Offspring
Authors: Terry Dellara F. , Wilcox Marsha A. , McCormick Maegan A. , Pennington JaeMi Y. , Schoenhofen Emily A. , Andersen Stacy L. , Perls Thomas T.
Published: November 2004

Objectives: To assess the cause of death for centenarians' offspring and controls.

Design: Cross‐sectional study.

Setting: Community‐based, nationwide sample.

Participants: Family pedigree information was collected on 295 offspring of centenarians (from 106 families with a parent already enrolled in the nationwide New England Centenarian Study) and on 276 controls (from 82 control families) from 1997 to 2000. Controls were individuals whose parents were born in the same year as the centenarians but at least one of whom died at the average life expectancy.

Measurements: Age at death and cause of death.

Results: Centenarians' offspring had a 62% lower risk of all‐cause mortality (P<.001), a 71% lower risk of cancer‐specific mortality (P=.002), and an 85% lower risk of coronary heart disease–specific mortality (P<.001). Significant differences were not found for other causes of death. However of those who died centenarian offsprings dead at a significantly younger age than controls.

Conclusion: These findings suggest that centenarians' offspring have lower all‐cause mortality rates and cause‐specific mortality rates for cancer and coronary heart disease. These results suggest that mechanisms for survival to exceptional old age may go beyond the avoidance or delay of cardiovascular disease and also include the avoidance or delay of cancer. Moreover survival advantage of centenarian offsprings may not be due to factors related to childhood mortality. Ultimately, survival to exceptional old age may involve lower susceptibility to a broad range of age‐related diseases, perhaps secondary to inhibition of basic mechanisms of aging.
Using the Minimum Data Set to Select Nursing Home Residents for Interview About Pain
Authors: Chu Lily , Schnelle John F. , Cadogan Mary P. , Simmons Sandra F.
Published: November 2004

Objectives: To determine how many nursing home residents can provide stable responses to a simple pain interview and whether a Minimum Data Set (MDS) cognitive performance measure can be used to identify these residents.

Design: Cross‐sectional descriptive study.

Setting: Thirty‐three community‐based nursing homes.

Participants: Eight hundred ninety‐five nursing home residents.

Measurements: Resident completion rate, stability, and interrater reliability of a four‐item interview derived from the Geriatric Pain Measure were calculated. Demographic data and MDS items concerning pain and memory were obtained from medical records.

Results: Overall, 835 residents were able to answer all four interview questions. At the lowest MDS recall score of 0, 52.7% of residents were able to complete all questions. All residents able to respond to the interview achieved high stability (kappa=0.633, P<.001). Overall, 62.8% of residents with daily pain or activity‐limiting pain on interview did not have daily or moderate to severe pain recorded on the MDS. Residents who had lower MDS recall scores were significantly less likely (P=.004) to be appropriately identified on the MDS.

Conclusion: Residents with a low MDS recall score were significantly less likely to be noted on the MDS as having serious pain despite being able to complete a simple yes/no interview about pain in a stable fashion. Nursing staff should attempt to ask all residents direct questions about pain. Surveyors may restrict direct questioning to those residents with an MDS recall score of 1 or higher if time is an important consideration. Adjustment for MDS‐derived prevalence of pain based on residents' cognitive status is questionable.
Persistent Pain in Frail Older Adults After Hip Fracture Repair
Authors: Herrick Cynthia , Steger‐May Karen , Sinacore David R. , Brown Marybeth , Schechtman Kenneth B. , Binder Ellen F.
Published: November 2004

Objectives: To identify factors associated with persistent hip pain in elderly hip fracture patients with physical frailty.

Design: Cohort study.

Setting: Community‐based study conducted at academic medical center.

Participants: Eighty‐eight men and women (mean age±standard deviation 80±7 years) with a recent hip fracture (mean 14.5±4.8 weeks after hip fracture repair) and physical frailty, defined as a modified Physical Performance Test Score between 12 and 28, enrolled in an exercise intervention trial.

Measurements: Dependent variable was self‐report of moderate to severe regional hip pain in the week preceding the baseline interview. Independent variables were self‐reported demographic information, health characteristics, and activity of daily living (ADL) function; Yesavage Mood Score (YMS); 36‐item Short Form percentile scores; and objective measurements of lower extremity strength, range of motion, balance, and gait.

Results: Forty‐two percent of the sample reported moderate or severe hip pain at the baseline assessment. Moderate/severe pain was related to difficulty with ADL performance and multiple measures of quality of life. Variables independently associated with moderate/severe hip pain were frequency of pain medication use (adjusted odds ratio (AOR)=5.75, 95% confidence interval (CI)=2.23–14.82, P=.003), YMS score (AOR=2.69, 95% CI=1.18–6.12, P=.02), and knee extension at 60°/s in the fractured limb (AOR=0.96, 95% CI=0.92–1.0, P=.05, model coefficient of determination=0.34).

Conclusion: Persistent hip pain is a frequent symptom in frail elderly community‐dwelling hip fracture patients. Pain medication use, symptoms of depression, and skeletal muscle weakness of the fractured leg are independent correlates of moderate to severe hip pain in this patient population. Clinicians should assess for, and address, persistent pain in this patient population.
Self‐Reported Delay in Seeking Care Has Poor Validity for Predicting Adverse Outcomes
Authors: Rupper Randall W. , Konrad Thomas R. , Garrett Joanne M. , Miller William , Blazer Dan G.
Published: November 2004

Objectives: To determine whether self‐reports of delayed care predict increased mortality and functional decline in community‐dwelling elderly.

Design: Longitudinal cohort study.

Setting: Five counties in North Carolina.

Participants: A total of 4,162 randomly sampled individuals aged 65 and older.

Measurements: The primary outcome was the proportional hazard ratio (HR) for death in cohorts stratified by self‐reports of delayed or foregone care. A secondary outcome, functional decline, measured the cohorts' odds of developing increased dependency in activities of daily living (ADLs). Control variables included predisposing, enabling, and need factors.

Results: Of 3,964 eligible participants reporting, 61% never, 27% once in a while, and 12% quite often delayed care. Over 3 years, 13% of participants died, and 17% developed increased ADL dependency. Nevertheless, in unadjusted and adjusted models, neither 3‐year mortality HRs nor the odds of functional decline differed between cohorts reporting varying degrees of delayed care. Survival probabilities remained higher for 15 years among those reporting delaying care often.

Conclusion: The inability of self‐reported delay to predict adverse outcomes in community‐dwelling elderly suggests the need for better understanding and support of the care‐seeking process and additional measures of timeliness of access.