bluuebunny/crossref_metadata_2025 huggingface dataset:
Biosynthesis of plant phenolic compounds in elevated atmospheric CO2
Authors: Hartley Susan E. , Jones Clive G. , Couper Gordon C. , Jones T. Hefin
Published: March 2003

Experiments were carried out to determine the effects of elevated atmospheric carbon dioxide (CO2) on phenolic biosynthesis in four plant species growing over three generations for nine months in a model plant community. Results were compared to those obtained when the same species were grown individually in pots in the same soils and controlled environment. In the model herbaceous plant community, only two of the four species showed any increase in biomass under elevated CO2, but this occurred only in the first generation for Spergula arvensis and in the second generation for Poa annua. Thus, the effects of CO2 on plant biomass and carbon and nitrogen content were species‐ and generation‐specific. The activity of the principle phenolic biosynthetic enzyme, phenylalanine ammonia lyase (PAL), increased under elevated CO2 in Senecio vulgaris only in Generation 1, but increased in three of the four plant species in Generation 2. There were no changes in the total phenolic content of the plants, except for P. annua in Generation 1. Lignin content decreased under elevated CO2 in Cardamine hirsuta in Generation 1, but increased in Generation 2, whilst the lignin content of P. annua showed no change, decreased, then increased in response to elevated CO2 over the three generations. When the species were grown alone in pots, elevated CO2 increased PAL activity in plants grown in soil taken from the Ecotron community after nine months of plant growth, but not in plants grown in the soil used at the start of the experiment (‘initial' soil). In P. annua, phenolic biosynthesis decreased under elevated CO2 in initial soil, and in both P. annua and S. vulgaris there was a significant interaction between effects of soil type and CO2 level on PAL activity. In this study, plant chemical composition altered more in response to environmental factors such as soil type than in response to carbon supply. Results were species‐specific and changed markedly between generations.
Long‐term dynamics of pine and hardwood litter in contrasting environments: toward a global model of decomposition
Authors: Gholz Henry L. , Wedin David A. , Smitherman Stephen M. , Harmon Mark E. , Parton William J.
Published: March 2003

We analysed data on mass loss after five years of decomposition in the field from both fine root and leaf litters from two highly contrasting trees, Drypetes glauca, a tropical hardwood tree from Puerto Rico, and pine species from North America as part of the Long‐Term Intersite Decomposition Experiment (LIDET). LIDET is a reciprocal litterbag study involving the transplanting of litter from 27 species across 28 sites in North and Central America reflecting a wide variety of natural and managed ecosystems and climates, from Arctic tundra to tropical rainforest. After 5 years, estimated k‐values ranged from 0.032 to 3.734, lengths of Phase I (to 20% mass remaining) from 0.49 to 47.92 years, and fractional mass remaining from 0 to 0.81. Pine litter decomposed more slowly than Drypetes litter, supporting the notion of strong control of substrate quality over decomposition rates. Climate exerted strong and consistent effects on decomposition. Neither mean annual temperature or precipitation alone explained the global pattern of decomposition; variables including both moisture availability and temperature (i.e. actual evapotranspiration and DEFAC from the CENTURY model) were generally more robust than single variables. Across the LIDET range, decomposition of fine roots exhibited a Q10 of 2 and was more predictable than that of leaves, which had a higher Q10 and greater variability. Roots generally decomposed more slowly than leaves, regardless of genus, but the ratio of above‐ to belowground decomposition rates differed sharply across ecosystem types. Finally, Drypetes litter decomposed much more rapidly than pine litter in ‘broadleaved habitats’ than in ‘conifer habitats’, evidence for a ‘home‐field advantage’ for this litter. These results collectively suggest that relatively simple models can predict decomposition based on litter quality and regional climate, but that ecosystem‐specific problems may add complications.
Microbial processes influencing methane emission from rice fields
Authors: Krüger Martin , Frenzel Peter , Conrad Ralf
Published: March 2003

Irrigated rice fields are an important source of atmospheric methane. In order to improve our understanding of the controlling processes, we measured in situ CH4 emission and CH4 oxidation in an Italian rice field in 1998 and 1999, and studied CH4 production in soil and root samples. The CH4 emission rates were correlated with diurnal temperature variations and showed pronounced seasonal and interannual variations. The contribution of CH4 oxidation to total CH4 flux, determined by specific inhibition with difluoromethane, decreased from 40% at the beginning to zero at the end of the season. The stable carbon isotopic composition of the emitted CH4 also decreased. The CH4‐oxidizing bacteria probably became limited by nitrogen as indicated by the seasonal decrease of NH4+. Thus, CH4 oxidation had little effect on CH4 emission. Methane production on rice roots was relatively constant over the season. Methane production in soil slowly increased after flooding and was highest in the middle of the season. Pore water concentrations of CH4 showed a similar seasonal pattern. In 1999, CH4 production increased later in the season and reached lower rates than in 1998. An additional drainage in 1999 resulted in higher ferric iron concentrations, higher soil redox potentials and lower acetate concentrations. As a result, acetate‐utilizing methanogens were probably out‐competed by iron‐reducers so that a larger percentage of [2–14C]acetate was converted to 14CO2 instead of 14CH4. The residual CH4 production was relatively low and was mainly due to H2/CO2‐dependent methanogenesis. Experiments with radioactive bicarbonate and with methyl fluoride as specific inhibitor showed that the theoretical ratio of 7:3 of methanogenesis from acetate vs. H2/CO2 was only reached later in the season when total CH4 production was at the maximum. In conclusion, our results give a mechanistic explanation for the intraseasonal and interannual differences in CH4 emission.
Paired‐tower measurements of carbon and energy fluxes following disturbance in the boreal forest
Authors: Amiro Brian D.
Published: March 2003

Disturbances by fire and harvesting are thought to regulate the carbon balance of the Canadian boreal forest over scales of several decades. However, there are few direct measurements of carbon fluxes following disturbances to provide data needed to refine mathematical models. The eddy covariance technique was used with paired towers to measure fluxes simultaneously at disturbed and undisturbed sites over periods of about one week during the growing season in 1998 and 1999. Comparisons were conducted at three sites: a 1‐y‐old burned jackpine stand subjected to an intense crown fire at the International Crown Fire Modelling Experiment site near Fort Providence, North‐west Territories; a 1‐y‐old clearcut aspen area at the EMEND project near Peace River, Alberta; and a 10‐y‐old burned, mixed forest near Prince Albert National Park, Saskatchewan. Nearby mature forest stands of the same types were also measured as controls. The harvested site had lower net radiation (Rn), sensible (H) and latent (LE) heat fluxes, and greater ground heat fluxes (G) than the mature forest. Daytime CO2 fluxes were much reduced, but night‐time CO2 fluxes were identical to that of the mature aspen forest. It is hypothesized that the aspen roots remained alive following harvesting, and dominated soil respiration. The overall effect was that the harvested site was a carbon source of about 1.6 gC m−2 day−1, while the mature site was a sink of about −3.8 gC m−2 day−1. The one‐year‐old burn had lower Rn, H and LE than the mature jackpine forest, and had a continuous CO2 efflux of about 0.8 gC m–2 day−1 compared to the mature forest sink of − 0.5 g C m−2 day−1. The carbon source was likely caused by decomposition of fire‐killed vegetation. The 10‐y‐old burned site had similar H, LE, and G to the mature mixed forest site. Although the diurnal amplitude of the CO2 fluxes were slightly lower at the 10‐y‐old site, there was no significant difference between the daily integrals (− 1.3 gC m−2 day−1 at both sites). It appears that most of the change in carbon flux occurs within the first 10 years following disturbance, but more data are needed on other forest and disturbance types for the first 20 years following the disturbance event.
Detecting potential regional effects of increased atmospheric CO2 on growth rates of western juniper
Authors: Knapp Paul A. , Soulé Peter T. , Grissino‐Mayer Henri D.
Published: March 2003

Evidence of an atmospheric CO2 fertilization effect on radial growth rates was uncovered by examining climate–growth relationships for seven western juniper tree‐ring chronologies in central Oregon using multiple regression models. Consistent upward trends of the residuals from dendroclimatic models indicated a decreased ability for climate parameters to predict growth with time. Additionally, an assessment was made of whether enhanced growth was detectable under drought conditions, because a major benefit of elevated atmospheric CO2 is the reduction of water stress. Mean ring indices were compared between ecologically comparable drought years, when atmospheric CO2 was lower (1896–1949), and more recent drought years that occurred under higher atmospheric CO2 concentrations (1950–96/98). The results presented herein show that: (i) residuals from climate/growth models had a significant positive trend at six of seven sites, suggesting the presence of a nonclimatic factor causing increased growth during recent decades; (ii) overall growth was 23% greater in the latter half of the 20th century; (iii) growth indices during matched drought and matched wet years were 63% and 30% greater, respectively, in the later 20th century than the earlier 20th century; and (iv) harsher sites had greater responses during drought periods between early and late periods. While it is not possible to rule out other factors, these results are consistent with expectations for CO2 fertilization effects.
Leaf respiration is differentially affected by leaf vs. stand‐level night‐time warming
Authors: Griffin Kevin L. , Turnbull Matthew , Murthy Ramesh , Lin Guanghui , Adams John , Farnsworth Blake , Mahato Tilak , Bazin Guerric , Potasnak Mark , Berry Joe A.
Published: March 2003

Plant respiration is an important physiological process in the global carbon cycle serving as a major carbon flux from the biosphere to the atmosphere. Respiration is sensitive to temperature providing a link between environmental variability, climate change and the global carbon cycle. We measured leaf respiration in Populus deltoides after manipulating the air temperature surrounding part of a single leaf, and compared this to the temperature response of the same leaves after manipulating the temperature of the stand. The short‐term temperature response of respiration (Q10– change in the respiration rate with a 10 °C increase in leaf temperature) was 1.7 when the leaf temperature was manipulated, but 2.1 when the stand‐level temperature was changed. As a result, total night‐time carbon release during the five‐day experiment was 21% lower when using the Q10 estimates from the tradition leaf manipulation compared to the stand‐level manipulation. We conclude that the temperature response of leaf respiration is related to whole plant carbon and energy demands, and that appropriate experimental procedures are required in examining respiratory CO2 release under variable temperature conditions.
Potential changes in the distributions of latitudinally restricted Australian butterfly species in response to climate change
Authors: Beaumont Linda J. , Hughes Lesley
Published: March 2003

This study assessed potential changes in the distributions of Australian butterfly species in response to global warming. The bioclimatic program, BIOCLIM, was used to determine the current climatic ranges of 77 butterfly species restricted to Australia. We found that the majority of these species had fairly wide climatic ranges in comparison to other taxa, with only 8% of butterfly species having a mean annual temperature range spanning less than 3 °C.

The potential changes in the distributions of 24 butterfly species under four climate change scenarios for 2050 were also modelled using BIOCLIM. Results suggested that even species with currently wide climatic ranges may still be vulnerable to climate change; under a very conservative climate change scenario (with a temperature increase of 0.8–1.4 °C by 2050) 88% of species distributions decreased, and 54% of species distributions decreased by at least 20%. Under an extreme scenario (temperature increase of 2.1–3.9 °C by 2050) 92% of species distributions decreased, and 83% of species distributions decreased by at least 50%. Furthermore, the proportion of the current range that was contained within the predicted range decreased from an average of 63% under a very conservative scenario to less than 22% under the most extreme scenario.

By assessing the climatic ranges that species are currently exposed to, the extent of potential changes in distributions in response to climate change and details of their life histories, we identified species whose characteristics may make them particularly vulnerable to climate change in the future.
Carbon balance and radiative forcing of Finnish peatlands 1900–2100 – the impact of forestry drainage
Authors: Minkkinen Kari , Korhonen Riitta , Savolainen Ilkka , Laine Jukka
Published: March 2003

Natural peatlands accumulate carbon (C) and nitrogen (N). They affect the global climate by binding carbon dioxide (CO2) and releasing methane (CH4) to the atmosphere; in contrast fluxes of nitrous oxide (N2O) in natural peatlands are insignificant. Changes in drainage associated with forestry alter these greenhouse gas (GHG) fluxes and thus the radiative forcing (RF) of peatlands. In this paper, changes in peat and tree stand C stores, GHG fluxes and the consequent RF of Finnish undisturbed and forestry‐drained peatlands are estimated for 1900–2100. The C store in peat is estimated at 5.5 Pg in 1950. The rate of C sequestration into peat has increased from 2.2 Tg a‐‐1 in 1900, when all peatlands were undrained, to 3.6 Tg a‐‐1 at present, when c. 60% of peatlands have been drained for forestry. The C store in tree stands has increased from 60 to 170 Tg during the 20th century. Methane emissions have decreased from an estimated 1.0–0.5 Tg CH4‐‐C a‐‐1, while those of N2O have increased from 0.0003 to 0.005 Tg N2O‐‐N a‐‐1. The altered exchange rates of GHG gases since 1900 have decreased the RF of peatlands in Finland by about 3 mW m‐‐2 from the predrainage situation. This result contradicts the common hypothesis that drainage results in increased C emissions and therefore increased RF of peatlands. The negative radiative forcing due to drainage is caused by increases in CO2 sequestration in peat (‐‐0.5 mW m‐‐2), tree stands and wood products (‐‐0.8 mW m‐‐2), decreases in CH4 emissions from peat to the atmosphere (‐‐1.6 mW m‐‐2), and only a small increase in N2O emissions (+0.1 mW m‐‐2). Although the calculations presented include many uncertainties, the above results are considered qualitatively reliable and may be expected to be valid also for Scandinavian countries and Russia, where most forestry‐drained peatlands occur outside Finland.
Photosynthetic acclimation to elevated CO2 in Phaseolus vulgaris L. is altered by growth response to nitrogen supply
Authors: Jifon John L. , Wolfe David W.
Published: March 2003

Abstract Long‐term exposure of plants to elevated CO2 often leads to downward photosynthetic acclimation. Nitrogen (N) deficiency could potentially exacerbate this response by reducing growth rate and the sink for photosynthates, but this has not always been observed. Experimentally, the interpretation of N effects on CO2 responses can be confounded by increasing severity of tissue N deficiency over time when N supply is not adjusted as demand increases. In this study, N supply ranged from sub‐ to supra‐optimal (20–540 kgN ha–l equivalent), and relatively stable levels of tissue N concentration were obtained in all treatments by varying twice‐weekly application rates in proportion to plant growth. The effects of N on photosynthesis and growth of beans (Phaseolus vulgaris L.) raised at ambient (35 Pa) and three elevated (70, 105, 140 Pa) CO2 partial pressures (pCO2) were evaluated. Averaging across N treatments, leaf total non‐structural carbohydrates (TNC) were 2.5‐ to 3‐fold higher and leaf N concentrations were 31–35% lower at elevated compared to ambient pCO2. Light‐saturated net CO2 assimilation rates measured at growth pCO2 (Asatg) were significantly higher (26–40% depending on N supply) in plants grown at elevated compared to ambient pCO2. When measured at a common pCO2 of 35 Pa, the Asat of plants grown at elevated CO2 was 15–29% less than that of plants grown at 35 Pa, indicative of downward photosynthetic acclimation. The magnitude of downward photosynthetic acclimation to elevated CO2 was greater in plants grown at high (180 and 540 kgN ha–l) compared to low (20 and 60 kgN ha–l) N supply, and this was associated with a higher Asat at growth pCO2, higher leaf area ratio (leaf area/total biomass), and higher TNC in leaves of high‐N plants. Our results indicate that the effect of N on acclimation to CO2 will depend on the balance between supply and demand for N during the growing period, and the effect this has on biomass allocation and source‐sink C balance at the whole‐plant level.
Impacts of plant roots on soil CO cycling and soil–atmosphere CO exchange
Authors: KING GARY M. , CROSBY HEIDI
Published: March 2003

Carbon monoxide (CO) plays a major role in tropospheric chemical dynamics. Accordingly, global CO budgets have been reasonably well documented. Atmospheric CO consumption by soils contributes significantly to these budgets, with the magnitude of the sink generally considered to reflect a balance between microbial uptake and abiological production. However, assays of live fine roots showed that diverse intact plants produced carbon monoxide at net rates ranging from 2 to 3000 mµg gdw−−1 d−−1. CO production was greater for legumes than nonlegumes, and primarily associated with nodules. Excised roots from woody and herbaceous plants produced CO at comparable rates. CO production rates were similar for roots of intact plants and roots excised from those plants. The magnitude of net CO fluxes from roots was determined in part by the balance between simultaneous production and consumption. Surface sterilization of roots indicated that CO consumption was due, in part, rhizoplane CO‐oxidizing bacteria, but maximum CO consumption rates were typically only a small fraction of net production rates. Assays in a Brazilian agroecosystem indicated that root CO production affects soil–atmosphere CO exchange. Estimates of global CO production rates indicated that roots contribute about 170–260 Tg CO to the soil atmosphere annually, an amount comparable to current estimates of atmospheric CO uptake by soils, and much larger than estimates of net abiological soil CO production.
A cross‐biome comparison of daily light use efficiency for gross primary production
Authors: TURNER DAVID P. , URBANSKI SHAWN , BREMER DALE , WOFSY STEVEN C. , MEYERS TILDEN , GOWER STITH T. , GREGORY MATTHEW
Published: March 2003

Vegetation light use efficiency is a key physiological parameter at the canopy scale, and at the daily time step is a component of remote sensing algorithms for scaling gross primary production (GPP) and net primary production (NPP) over regional to global domains. For the purposes of calibrating and validating the light use efficiency (εg) algorithms, the components of εg– absorbed photosynthetically active radiation (APAR) and ecosystem GPP – must be measured in a variety of environments. Micrometeorological and mass flux measurements at eddy covariance flux towers can be used to estimate APAR and GPP, and the emerging network of flux tower sites offers the opportunity to investigate spatial and temporal patterns in εg at the daily time step. In this study, we examined the relationship of daily GPP to APAR, and relationships of εg to climatic variables, at four micrometeorological flux tower sites – an agricultural field, a tallgrass prairie, a deciduous forest, and a boreal forest. The relationship of GPP to APAR was close to linear at the tallgrass prairie site but more nearly hyperbolic at the other sites. The sites differed in the mean and range of daily εg, with higher values associated with the agricultural field than the boreal forest. εg decreased with increasing APAR at all sites, a function of mid‐day saturation of GPP and higher εg under overcast conditions. εg was generally not well correlated with vapor pressure deficit or maximum daily temperature. At the agricultural site, a εg decline towards the end of the growing season was associated with a decrease in foliar nitrogen concentration. At the tallgrass prairie site, a decline in εg in August was associated with soil drought. These results support inclusion of parameters for cloudiness and the phenological status of the vegetation, as well as use of biome‐specific parameterization, in operational εg algorithms.
Harvest management effects on alfalfa (Medicago sativaL.) production and quality in Mediterranean areas
Authors: Lloveras J. , Ferran J. , Alvarez A. , Torres L.
Published: March 2003

The effects of plant harvest stage, autumn harvest dateand cultivars on alfalfa production and quality weredetermined in a 3‐year field experiment established in1992. Harvesting stage influenced annual yield andquality. Late bud‐first flower harvests increased harvestfrequency and forage quality in comparison with har‐vestingat the full bloom stage while decreasing dry‐matteryield by 18% (25·5 vs. 21·6 t ha 21 ). Harvestingstage significantly affected autumn forage productionand quality and yield at the first spring cut. Harvests atfull bloom allowed greater autumn and spring regrowththan cutting at the late bud stage, possibly because ofthe accumulation of higher root reserves. Autumn har‐vestsand cultivar significantly influenced the yields atthe first spring cut in any growing season. Cuttingbefore the first frost in autumn reduced the vigour ofboth cultivars, and the subsequent yield at the first cutin any year, in comparison with harvests taken after ornear the first autumn frost. It is concluded that theeffects of the stage of harvesting alfalfa on dry‐matterproduction and quality are important in theMediterranean environment of the Ebro Valley; theeffects of autumn management were observed mainlyon the yields of the subsequent first cut in spring but noton the total annual production.
Growing point dynamics and spring growth of white clover in a mixed sward and the effects of nitrogen application
Authors: Höglind  , Frankow‐Lindberg
Published: March 2003

The effects of N applied in spring on the growth and development of white clover (Trifolium repens L.) in a mixed sward were investigated at Uppsala, Sweden. In early spring, the plots received 0 or 90 kg N ha−1 in the form of nitrochalk. The formation and loss of stolon branches were followed on marked stolons. The proportion of white clover in the total above‐ground dry matter (DM) of the sward fell substantially in both treatments during the 8‐week growth period, but more so in N fertilized than in unfertilized plots; fertilizer N increased the accumulation of grass DM, whereas it reduced the accumulation of white clover DM. Over time, there was a loss of white clover growing points and this loss was greatest in plots where N was applied. Branching occurred predominantly during the first half of the growth period and was unaffected by N application, whereas the loss of branches was more confined to the latter period and was increased in plots receiving N. Irrespective of node position, the size of the branches that died was comparatively small, and more branches were lost from young than from old node positions. It is concluded that the decline in the number of growing points in the N fertilized sward was mainly due to an increased loss of recently formed branches. As a consequence of its stimulating effect on grass growth, the N fertilized treatment initially led to a reduction in the R:FR ratio of light and subsequently also in the availability of photosynthetically active radiation within the canopy. These changes in the light environment of the sward caused morphological adjustments to be made by the white clover and may have contributed to the observed loss of branches.
Effects of feeding ensiled kale (Brassica oleracea) on the performance of finishing lambs
Authors: Vipond  , Duncan  , Turner  , Goddyn  , Horgan
Published: March 2003

The use of forage brassicas, such as kale, in diets of ruminants is typically constrained by the presence of anti‐metabolites that break down in the rumen to cause detrimental effects after absorption including haemolytic anaemia and tissue damage. Ensilage of kale before feeding may provide conditions that favour the degradation of potentially toxic anti‐metabolites, thereby improving the nutritive value of the feed. An experiment was conducted with eighty Scottish Blackface housed lambs, in which four levels of kale silage were used to replace grass silage and in which the forage component comprised around 60% of the finishing diet. Productivity of lambs was not affected other than to increase the killing‐out percentage of the lambs. Glucosinolate concentrations in kale were markedly reduced by the ensiling process. Haematological parameters, such as packed cell volume, haemoglobin concentration and the presence of Heinz−Ehrlich bodies, were not significantly affected by replacing grass silage with kale silage. Similarly, there were no significant effects arising from the dietary treatments on the blood plasma components, gamma‐glutamyl transpeptidase, blood urea nitrogen, tri‐iodothyroxine and thyroxine, which are conventional measures of glucosinolate toxicity.

The results indicated that the ensilage of kale reduces its toxicity and hence removes constraints on the maximum inclusion levels in the diet. Also, it was possible to reduce the potential contamination of carcasses with soil by lambs not grazing the crop and thus keeping fleeces clean.
The efficacy of repeated applications of the urease inhibitorN‐(n‐butyl) thiophosphoric triamide for improving the efficiency of urea fertilizer utilization on temperate grassland
Authors: Watson C. J. , Poland P. , Allen M. B. D.
Published: March 2003

The effect ofN‐(n‐butyl) thiophosphoric triamide (nBTPT)‐amended urea on herbage dry‐matter yield and nitrogen offtake by perennial ryegrass (Lolium perenne) was studied in fifteen grassland experiments at two sites in Northern Ireland between 1994 and 1996. The dry‐matter yield and N offtake with applied urea was only significantly lower than that with applied calcium ammonium nitrate (CAN) on four occasions. On these occasions nBTPT increased the yield from the application of urea making it almost as effective as CAN. There was no evidence of any adverse effect on grass production with repeated applications of nBTPT‐amended urea over a 3‐year period and no indication that its efficacy to reduce NH3, loss from ureatreated swards declined when used repeatedly on the same soil.
The interactive effects of phosphorus, potassium, lime and molybdenum on the growth and morphology of white clover (Trifolium repens L.) at establishment
Authors: Bailey  , Laidlaw
Published: March 2003

The effects of simultaneously varying P, K, lime and Mo supplies on the growth and shoot morphology of white clover (Trifolium repens) at establishment were investigated in a factorially designed glasshouse experiment. Phosphorus and lime applications had almost identical, additive, effects on dry‐matter (DM) production, and it was clear that the benefit of both treatments lay in the resultant improvements in plant available P. The adverse effects of P deficiency on young plants resulted, immediately, in a large decrease in stolon branch numbers, but only when the deficiency became acute did similar declines in the dimensions of leaves and petioles occur. It was suggested that this preferential maintenance of leaf and petiole expansion processes under moderate P deficiency, by enabling white clover to retain favourable upper canopy positions, could be an ecological adaptation to maximize its chances of survival in mixed grass–clover swards. Unlike P, K had little effect on clover growth or shoot morphology. However, there was some evidence that plants suffering from acute K deficiency preferentially partitioned resources to organs associated with exploratory growth, i.e. to stolons, at the expense of the plant's photosynthetic capability. Molybdenum application had no effect on DM production or shoot morphology, but did improve the N status of shoots, presumably by enhancing N2 fixation. It was concluded that the survival of white clover in swards at establishment is critically dependent on P supply, and that one of the main benefits of liming is the resultant improvement in P availability.
Effect of Lactobacillus buchneri 40788 on the fermentation, aerobic stability and nutritive value of maize silage
Authors: Ranjit N. K. , Taylor C. C. , Kung Jr L.
Published: March 2003

The effect of adding Lactobacillus buchneri 40788, a heterofermentative lactobacilli, to whole‐plant maize and its effect on fermentation and aerobic stability of the resulting silage were evaluated. Whole‐plant maize (380 g DM kg–1 fresh weight) was ensiled in laboratory silos after the following treatments: untreated, L. buchneri 40788 at 1 × 105, 2·5 × 105, 5 × 105, and 1 × 106 colony forming units g–1 of fresh forage or, a commercial inoculant containing homolactic acid bacteria, a single species of propionibacteria and enzymes. Addition of L. buchneri 40788 resulted in a decrease in lactic acid concentration but increased the concentration of acetic acid in silage and markedly decreased the numbers of yeasts present in the silage. All levels of L. buchneri 40788, increased the aerobic stability of silages but the effect was greatest for the two highest levels of inoculation. Treatment with the commercial inoculant had no effect on the fermentation or aerobic stability of silage. On‐farm treatment of maize silage with L. buchneri 40788, stored in a bag silo, resulted in changes in fermentation that were similar to those observed in laboratory silos. Treatment decreased the numbers of yeast in silage and increased aerobic stability (+25 h) of the silage when exposed to air. Treatment had no effect on the dry‐matter intake of silage fed to sheep. These results showed that treating silage with L. buchneri 40788 can increase the aerobic stability of maize silage in laboratory and farm silos.
Safe insertion of trocars and the Veress needle using standard equipment and the 11 security steps
Authors: Semm Kurt , Semm Isolde
Published: March 2003

Objective

To increase the safety of trocar insertion, bearing in mind that 43% of laparoscopic injuries occur during the first minutes of the procedure, and are linked to the method of entry.

Design

The development of 11 safety tests, all under visual control: (1) palpation of the aorta; (2) needle flow resistance; (3) snap test; (4) hiss test; (5) negative pressure test; (6) aspiration test; (7) ‘quadro’ test; (8) sounding test; (9) ‘Z’‐track incision; (10) trocar insertion under visual control; (11) 360° circumferential view.

Setting

The University Hospital for Women in Kiel, Germany.

Results

In 6000 laparoscopies, only one bowel perforation occurred.

Conclusion

Blind puncture of the abdominal wall should be proscribed in the next millenium.
Hysteroscopic fallopian tube recanalization using a flexible guide cannula and hydrophilic guide wire
Authors: Allahbadia Gautam N. , Mangeshikar Prashant , Dhungat P. B. Pai , Desai Sadhana K. , Gudi Anil A. , Arya Anup
Published: March 2003

Objective

To evaluate an innovative and simple procedure of hysteroscopic recanalization of cornual occlusion using a diagnostic hysteroscopic sheath, a Labotect flexible guide cannula and a Terumo hydrophilic guide wire, which were all used under laparoscopic guidance.

Design

In this prospective study, 17 patients with primary or secondary infertility with proven bilateral cornual blockage were scheduled for a recanalization procedure, between June 1995 and October 1998.

Setting

University‐based teaching hospital and the principal author's private clinic.

Subjects and methods

We combined hysteroscopic cannulation of the proximal fallopian tube using a Labotectcannula with laparoscopic guidance in 17 patients with proximal tubal obstruction which had been diagnosed by hysterosalpingography and confirmed at laparoscopy. This procedure, in addition to being minimally invasive, also accomplishes the objective of causing minimal trauma to the fallopian tube by virtue of the dual hysteroscopic and laparoscopic guidance.

Main outcome measures

Successful on‐table atraumatic recanalization of blocked fallopian tubes, documented by laparoscopic chromopertubation.

Results

Hysteroscopic cannulation could be attempted in 30 tubal ostia and was successfully accomplished in 15 cases. The instances in which we could not cannulate the tubal ostia (two patients) were not failures of cannulation but failures to visualize the internal tubal ostia because of thick endometrium. Four of our patients have conceived following this procedure and have delivered at term.

Conclusion

Hysteroscopic cannulation of the fallopian tube is a safe diagnostic procedure that can be used to identify those patients with true proximal occlusion, and may also serve as a therapeutic procedure in some of these patients. We recommend the use of a depot gonadotrophin‐releasing agonist, such as triptorelin, 10–15 days before attempting this procedure, for easy visualization and access to the internal tubal ostia. The relative simplicity of the procedure means a shorter learning curve for clinicians in training and other beginners, and the results can be consistently reproduced as shown by the 15 successful cases in this study.
Analysis of clinical AIDS‐free interval after CD4+ cell counts fall below 200 × 106L−1in Japanese Haemophiliacs infected with HIV‐1
Authors: Tatsunami  , Mimaya  , Meguro  , Kuwabara  , Yago  , Yamada
Published: March 2003

We analysed the time from the date CD4+ cell counts fell below 200 × 106L−1, defined asti, to the onset of clinical AIDS, according to the 1987 Centers for Disease Control and Prevention case definition, in 129 Japanese Haemophilia patients infected with HIV‐1. The cumulative onset of clinical AIDS was analysed by the Kaplan–Meier method and proportional hazard model. Incorporated covariates were age of each patient at timeti,as well as CD4+ and CD8+ cell counts, serum levels of IgG, IgA, IgM, GOT and GPT atti. The time of antiretroviral treatment initiation was also considered. The 50% AIDS‐free interval aftertiwas 3.00 years (95% confidence interval (CI), range 0.49–5.51) and 1.71 years (95% CI, range 0.66–2.76) for the patients at CDC stage II and stage III, respectively (significantly different,P= 0.0013). Among the patients at CDC stage II atti, higher levels of IgA were tightly associated with a shorter period fromtito onset of clinical AIDS (P< 0.0001), and relative hazard was 1.35 (95% CI, 1.11–1.64) with increase of IgA level by 1.0 g L−1. Thus there is a broad distribution in the time to onset of clinical AIDS in Japanese Haemophiliacs even after CD4+ cell counts fall below 200 × 106L−1. This should be taken into consideration in deciding upon the therapy and care of HIV‐1 infected people.
Knowledge of HIV/AIDS and emotional adjustment in a cohort of men with haemophilia and HIV infection: final report
Authors: Marsettin E. Pasqual , Ciavarella  , Lobaccaro  , Ghirardini  , Puopolo  , Cultraro  , Morfini  , Rocino
Published: March 2003

This study presents the final report of a long‐term psychological assessment of men with haemophilia and HIV infection. The knowledge, emotional impact regarding HIV infection and prospective changes over time and the need for psychological support were evaluated.

The study group comprised 118 men with haemophilia, 66 HIV seropositive and 52 seronegative, from the Haemophilia Centres in Bari, Florence, Milan and Naples.

All subjects performed psychological tests (STAI: state and trait anxiety inventory; SDS: self‐rating depression scale) and completed questionnaires to ascertain their knowledge and the emotional impact of AIDS. After enrolment (1992–93) the assessment was repeated twice over a 2‐year period. A high percentage of subjects in both groups answered the questionnaire on knowledge correctly and, more specifically, all (100%) admitted knowing that sexual intercourse was a risk factor for HIV infection, adding that sexual partners of haemophiliacs with HIV should be regularly tested. The percentage, however, decreased for seropositives who admitted to always using a condom during sexual intercourse (86%) and for those who declared that partners were periodically tested for HIV (60%).

The most important feature of the study is that, contrary to predicted expectations, seropositive and seronegative subjects presented the same degree of emotional involvement: there are no statistically significant differences in average scores between groups either on the anxiety or depression scales. Moreover, for certain aspects, seronegatives revealed greater emotional involvement: at baseline evaluation, they felt more fear and unhappiness with statistically significant differences compared to asymptomatics. Furthermore, seronegatives more than seropositives continue to feel reluctance towards infusion and avoid blood products after learning of AIDS. These results emphasize the importance of paying due attention to the emotional status of seronegatives. Their reluctance towards the use of blood products (despite present safety) is a very important issue for the possible consequences of treatment with the risk of worsening the clinical condition. In conclusion, we believe that counselling on HIV infection/AIDS needs to address every person with haemophilia regardless of HIV status.
Factor XI deficiency in the French Basque Country
Authors: Bauduer  , Dupreuilh  , Ducout  , Marti
Published: March 2003

Thirty‐nine patients with factor XI deficiency were diagnosed in our general hospital, which serves all the French Basque Country (about 290 000 inhabitants), between 1985 and 1995. Biological and clinical data of these cases are reported herein. Factor XI deficiency seems significantly more frequent in Basques than in the other non‐Ashkenazi populations. Molecular studies should be performed for typing these cases in the view of population genetics.
Changes in hepatitis B serologic titers in HIV+ and HIV– children with haemophilia
Authors: Kisker  , Mahoney  , Arkin  , Maeder  , Donfield  , Evatt  ,   THE HEMOPHILIA GROWTH DEVELOPMENT STUDY
Published: March 2003

This longitudinal study examines differences in hepatitis B immune titres in children and adolescents with haemophilia to determine if they are dependent on how immunity was acquired (vaccination or natural infection), and whether they are related to the child’s HIV status and/or are influenced by HIV disease progression.

Serologic titres (HBcAb, HBsAb) and HBsAg were measured prospectively at baseline, and at years 1, 2 and 3 of follow‐up in 126 HIV– and 207 HIV+ children and adolescents with haemophilia. Analyses were performed to assess the impact of HIV status on the measured titres, and for HIV+ subjects to examine the association with CD4+ lymphocyte counts and p24 antigen status.

The results show that HIV+ children were more likely than HIV– children to lose vaccine‐induced immunity as indicated by the loss of HBsAb. There was an increased risk of losing HBsAb with higher CD4+ counts and younger age. Re‐immunization was not successful in seven of eight HIV+ children. Two subjects (one HIV+ , one HIV–) entered the study HBsAg− but became HBsAg+ over the course of follow‐up. Seven HIV+ subjects lost natural immunity as indicated by the loss of HBcAb. The loss of either HBsAb or HBcAb in HIV– subjects was negligible to absent.

In conclusion, because of the loss of immunity in HIV+ children the viral safety of factor replacement concentrates for these children is an important consideration. HIV– children rarely lose immunity, therefore frequent measures of HBsAb are not necessary.
Assessing health‐related quality‐of‐life in individuals with haemophilia
Authors: Miners  , Sabin  , Tolley  , Jenkinson  , Kind  , Lee
Published: March 2003

The objectives of this study were to analyse current levels of health‐related quality‐of‐life (HR‐QoL) in individuals with severe haemophilia and to assess the scope for these levels to improve. To do this, 249 individuals with severe, moderate and mild haemophilia were asked to complete Medical Outcomes Study (MOS) Short‐Form 36 (SF‐36) and EuroQol (EQ‐5D) questionnaires. Access was also gained to two appropriate normative data sets. The results from these questionnaires showed that HIV status, history of orthopaedic surgery and bleeding frequency in the previous calendar year were not strong predictors of HR‐QoL for individuals with severe haemophilia. However, for the majority of scales, age was found to be a strong predictor of HR‐QoL for this patient group. The results from the analysis also showed that compared to individuals with moderate/mild haemophilia and the UK male normative population, individuals with severe haemophilia generally recorded poorer levels of HR‐QoL. These results suggest, therefore, that individuals with severe haemophilia have reduced levels of HR‐QoL compared to individuals with moderate/mild haemophilia and the general population, irrespective of differences in age. The results also suggest that the scope for primary prophylaxis to increase HR‐QoL in individuals with severe haemophilia is significant.
von Willebrand disease in Finland
Authors: Kekomäki R. , Rasi V. , Ebeling F. , Vahtera E. , Javela K. , Koski T. , Myllylä G. , Ikkala E.
Published: March 2003

The Finnish Red Cross Blood Transfusion Service has served as the national reference laboratory for haemostasis for more than 40 years and remains still the only one in the country to diagnose inherited coagulation factor deficiencies. By September 1997, 1076 patients with von Willebrand disease (vWD) were registered. The severity of bleeding symptoms leading to diagnosis varied according to the type of vWD. After prepubertal phase distinctly more female than male patients were diagnosed. The prevalence of severe type 3 vWD is 4:1 000 000.
Reproductive choices of women in families with haemophilia
Authors: Kadir  , Sabin  , Goldman  , Pollard  , Economides  , Lee
Published: March 2003

To assess women’s experiences in pregnancy and attitudes towards their reproductive choices, a structured questionnaire was sent to all obligate and potential carriers of haemophilia (A and B), aged 14–60 years, registered with our haemophilia centre. One hundred and ninety‐seven of 545 (36%) returned completed questionnaires. Clinical details, including type and severity of the disease in the family and results of DNA analysis for carrier detection, were obtained from patient notes. One hundred and sixty women had been pregnant at least once, of whom 36 (23%) had received a prenatal diagnostic test. Of the 41 women who had pregnancy terminations, haemophilia was the main reason in only 11 (27%) women. This decision was affected by the woman’s religion and results of DNA studies. Living close to a haemophilia centre, proper counselling at the centre and awareness of the availability of prenatal diagnostic tests influenced the women’s decision to become pregnant in 14% and 10% of first and subsequent pregnancies, respectively. These factors were considered more frequently in women with severe haemophilia in the family (P = 0.002) and in confirmed carriers of haemophilia (P = 0.04). When women made a conscious decision not to have children, the reasons were fear of passing haemophilia onto their child (44%), previous experience with haemophilia (6%) and the stress of going through prenatal tests (7%). Severity of the disease in the family, haemophilia diagnosis, results of DNA studies, religion and year of birth had no effect on this decision. Our data indicate that haemophilia and related factors in the family have an influence on women’s reproductive choices.
Thrombosis in a duplicated superficial femoral vein in a patient with haemophilia A
Authors: Stewart  , Manson  , Dennis  , Allan  , Ludlam
Published: March 2003

Venous thrombosis is a very rare occurrence in patients with haemophilia A. We report the case of a haemophiliac in whom initially a calf haematoma was suspected, but neither this nor deep venous thrombosis (DVT) could be confirmed on ultrasound scanning. Subsequently, a high segment venous thrombosis was diagnosed by venography in a portion of a duplicated superficial femoral vein. Treatment with factor VIII (FVIII) and low molecular weight heparin led to a successful resolution. The only other case we have been able to find in the literature occurred during FVIII replacement therapy, which was not the situation with our patient.
Maintenance of safer sexual behaviours: evaluation of a theory‐based intervention for HIV seropositive men with haemophilia and their female partners
Authors: Parsons J. T. , Huszti H. C. , Crudder S. O. , Rich L. , Mendoza J.
Published: March 2003

A theory‐based HIV risk‐reduction intervention was developed for HIV‐positive men with haemophilia and their HIV‐negative female romantic partners. The intervention was based on Prochaska and DiClemente’s Transtheoretical Model which describes behaviour change as an incremental, stage‐based process. The intervention targeted both communication about safer sex and safer sex behaviours (consistent condom use or abstinence from vaginal intercourse). A total of 255 males and 158 females from six funded haemophilia treatment centres or patient organizations (and 27 associated subsites) participated in the study. Baseline and follow‐up (15 months after baseline) measures were administered to assess safer sexual behaviours, communication about safer sex and condom self‐efficacy. A quasi‐experimental, repeated measures design was utilized to compare two naturally occurring groups; those who received the full intervention package and those who received incomplete or no intervention components. Significant intervention effects for safer sex behaviours, communication about safer sex and condom self‐efficacy were identified for the male participants, with those receiving the full intervention package demonstrating better outcomes at follow‐up. Women who received the full intervention package were more likely to report the use of a condom by their male partner during the last act of vaginal intercourse.