bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of soil temperature on nitric oxide emission from a typical Chinese rice–wheat rotation during the non‐waterlogged period
Authors: ZHENG XUNHUA , HUANG YAO , WANG YUESI , WANG MINGXING , JIN JISHENG , LI LAOTU 
Published: December 2004

AbstractMeasurements of nitric oxide (NO) emission from a typical Chinese rice–wheat rotation are continuously made during the non‐waterlogged period by using an automatic system based on static chamber techniques. A positive correlation exists between NO emission and soil moisture content when surface soil temperature is > 20 °C. The diurnal variability in NO emission is characterized with day‐peak, night‐peak and irregular patterns, which are in close association with wheat growth. The diurnal NO emission under the day‐peak pattern is correlated with the simultaneously observed surface soil temperature, whereas that under the night‐peak and irregular pattern is dependent on surface soil temperature at 7 ± 2 and 3 ± 2 h before NO observation, respectively. The effect of soil temperature on NO emission is well described by F = α·eβ·T, where F is NO flux, T soil temperature, and α and b empirical coefficients. The parameter Q10; that is, the change in NO emission per 10 °C soil temperature, is correlated with the rates of fertilizer‐N application. An approach orientated from the Arrhenius equation, , is developed in order to predict diurnal NO emission, where TK is the daily average soil temperature, ΔTK the deviation of soil temperature from the daily average, Ea the apparent activation energy, R the gas constant, t a given time within the one‐day cycle, t delayed time for appearance of the diurnal NO emission peak, and k an empirical coefficient. Based on the results, the authors recommend that intermittent measurement of NO emission from a similar ecosystem would be best taken around 17:00. The molar ratio of NO/N2O over the non‐waterlogged period is > 1 when soil moisture content was less than the field capacity, suggesting that NO emission was mainly derived from nitrification under this condition.
Sex‐specific physiological and growth responses to elevated atmospheric CO2 in Silene latifolia Poiret
Authors: WANG XIANZHONG , GRIFFIN KEVIN L. 
Published: December 2004

AbstractDioecy is found in nearly half of the angiosperm families, but little is known about how rising atmospheric CO2 concentration will affect male and female individuals of dioecious species. We examined gender‐specific physiological and growth responses of Silene latifolia Poiret, a widespread dioecious species, to a doubled atmospheric CO2 concentration in environmentally controlled growth chambers. Elevated CO2 significantly increased photosynthesis in both male and female plants and by a similar magnitude. Males and females did not differ in net photosynthetic rate, but females had significantly greater biomass production than males, regardless of CO2 concentrations. Vegetative mass increased by 39% in males and in females, whereas reproductive mass increased by 82% in males and 97% in females at elevated CO2. As a result, proportionately more carbon was allocated to reproduction in male and female plants at elevated CO2. Higher CO2 increased individual seed mass significantly, but had no effect on the number or mass of seeds per female plant. Our results demonstrated that rising atmospheric CO2 will alter the allocation patterns in both male and female S. latifolia Poiret plants by shifting proportionally more photosynthate to reproduction.
Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: past, present and future
Authors: BALDOCCHI DENNIS D. 
Published: December 2004

AbstractThe eddy covariance technique ascertains the exchange rate of CO2 across the interface between the atmosphere and a plant canopy by measuring the covariance between fluctuations in vertical wind velocity and CO2 mixing ratio. Two decades ago, the method was employed to study CO2 exchange of agricultural crops under ideal conditions during short field campaigns. During the past decade the eddy covariance method has emerged as an important tool for evaluating fluxes of carbon dioxide between terrestrial ecosystems and the atmosphere over the course of a year, and more. At present, the method is being applied in a nearly continuous mode to study carbon dioxide and water vapor exchange at over a hundred and eighty field sites, worldwide. The objective of this review is to assess the eddy covariance method as it is being applied by the global change community on increasingly longer time scales and over less than ideal surfaces.The eddy covariance method is most accurate when the atmospheric conditions (wind, temperature, humidity, CO2) are steady, the underlying vegetation is homogeneous and it is situated on flat terrain for an extended distance upwind. When the eddy covariance method is applied over natural and complex landscapes or during atmospheric conditions that vary with time, the quantification of CO2 exchange between the biosphere and atmosphere must include measurements of atmospheric storage, flux divergence and advection.Averaging CO2 flux measurements over long periods (days to year) reduces random sampling error to relatively small values. Unfortunately, data gaps are inevitable when constructing long data records. Data gaps are generally filled with values produced from statistical and empirical models to produce daily and annual sums of CO2 exchange. Filling data gaps with empirical estimates do not introduce significant bias errors because the empirical algorithms are derived from large statistical populations. On the other hand, flux measurement errors can be biased at night when winds are light and intermittent. Nighttime bias errors tend to produce an underestimate in the measurement of ecosystem respiration.Despite the sources of errors associated with long‐term eddy flux measurements, many investigators are producing defensible estimates of annual carbon exchange. When measurements come from nearly ideal sites the error bound on the net annual exchange of CO2 is less than ±50 g C m−2 yr−1. Additional confidence in long‐term measurements is growing because investigators are producing values of net ecosystem productivity that are converging with independent values produced by measuring changes in biomass and soil carbon, as long as the biomass inventory studies are conducted over multiple years.
Carbon distribution of a well‐ and poorly‐drained black spruce fire chronosequence
Authors: WANG CHUANKUAN , BOND‐LAMBERTY BEN , GOWER STITH T. 
Published: December 2004

AbstractThe objective of this study was to quantify carbon (C) distribution for boreal black spruce (Picea mariana(Mill.) BSP) stands comprising a fire chronosequence in northern Manitoba, Canada. The experimental design included seven well‐drained (dry) and seven poorly‐drained (wet) stands that burned between 1998 and 1850. Vegetation C pools (above‐ground + below‐ground) steadily increased from 1.3 to 83.3 t C ha−1for the dry chronosequence, and from 0.6 to 37.4 t C ha−1for the wet chronosequence. The detritus C pools (woody debris + forest floor) varied from 10.3 to 96.0 t C ha−1and from 12.6 to 77.4 t C ha−1for the dry and wet chronosequence, respectively. Overstorey biomass, mean annual biomass increment (MAI), woody debris mass, and litterfall were significantly greater (α = 0.05) for the dry stands than for the wet stands, but the bryophyte, understorey, and forest floor C pools were significantly less for the dry than for the wet stands. The root mass ratio decreased with stand age until 37 years after fire, was fairly constant thereafter, and was not significantly affected by soil drainage. The C pools of the overstorey and bryophyte tended to increase with stand age. Foliage biomass, litterfall, and MAI (for the dry stands) peaked at 71 years after fire and declined in the oldest stands. The results from this study illustrate that the effects of disturbance and edaphic conditions must be accounted for in boreal forest C inventories and C models. The appropriateness of using chronosequences to examine effects of wildfire on ecosystem C distribution is discussed.
Estimation of nitrous oxide, nitric oxide and ammonia emissions from croplands in East, Southeast and South Asia
Authors: YAN XIAOYUAN , AKIMOTO HAJIME , OHARA TOSHIMASA 
Published: December 2004

AbstractAgricultural activities have greatly altered the global nitrogen (N) cycle and produced nitrogenous gases of environmental significance. More than half of all chemical N fertilizer produced globally is used in crop production in East, Southeast and South Asia, where rice is central to nutrition. Emissions of nitrous oxide (N2O), nitric oxide (NO) and ammonia (NH3) from croplands in this region were estimated by considering background emission and emissions resulting from N added to croplands, including chemical N, animal manure, biologically fixed N and N in crop residues returned to fields. Background emission fluxes of N2O and NO from croplands were estimated to be 1.22 and 0.57 kg N ha−1 yr−1, respectively. Separate fertilizer‐induced emission factors were estimated for upland fields and rice fields. Total N2O emission from croplands in the study region was estimated to be 1.19 Tg N yr−1, with 43% contributed by background emissions. The average fertilizer‐induced N2O emission, however, accounts for only 0.93% of the applied N, which is less than the default IPCC value of 1.25%, because of the low emission factor from paddy fields. Total NO emission was 591 Gg N yr−1 in the study region, with 40% from background emissions. The average fertilizer‐induced NO emission factor was 0.48%. Total NH3 emission was estimated to be 11.8 Tg N yr−1. The use of urea and ammonium bicarbonate and the cultivation of rice led to a high average NH3 loss rate from chemical N fertilizer in the study region. Emissions were displayed at a 0.5° × 0.5° resolution with the use of a global landuse database.
Protein degradation and fermentation characteristics of unwilted red clover and alfalfa silage harvested at various times during the day
Authors: Owens V. N. , Albrecht K. A. , Muck R. E. 
Published: December 2004

AbstractExtensive proteolysis during fermentation of high‐protein legumes reduces dietary N‐use efficiency in ruminants. Research has demonstrated that enhancing the level of fermentable carbohydrates in crops entering the silo may reduce protein degradation by increasing the rate of decline in pH. The objective was to evaluate whether delaying cutting time during the day, to allow accumulation of total non‐structural carbohydrates (TNC), would inhibit proteolysis in the silo. Red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) were harvested at 06.00, 10.00, 14.00 and 18.00 hours in 1993, 1994 and 1995, and ensiled without wilting. TNC accumulated in fresh forage during the day, with starch accounting for more than 0·50 of the daily change in TNC in fresh herbage of both species, except in red clover in 1995. The level of TNC in fresh forage did not consistently affect the extent of protein degradation in either species and, in all instances, alfalfa underwent more extensive proteolysis than red clover. Silage pH typically decreased and starch concentration increased as cutting time was delayed from 06.00 to 18.00 hours. Although the extent of proteolysis was largely unaffected by inherent increases in TNC, harvesting in the afternoon did provide several benefits including increased dry‐matter content, lower silage pH and higher starch concentrations. Effluent production is a concern in any unwilted silage system; there was therefore an added advantage of lower moisture content from cutting in the afternoon.
Factor X and its deficiency states
Authors: PERRY D. J. 
Published: December 2004

Summary. Factor X is one of the vitamin‐K‐dependent serine proteases. As a result of its position at the convergence of the intrinsic and extrinsic pathways of the clotting cascade, it plays a crucial role in blood coagulation. Factor X interacts with components of both pathways of coagulation, leading to its activation and the formation of the prothrombinase complex.The gene for factor X has been cloned and sequenced and maps to the long arm of chromosome 13, approximately 2.8 kb downstream of the factor VII gene. Each of the exons of factor X encodes a specific functional domain within the protein. In terms of its gene structure and amino acid sequence, factor X shows significant homology with other vitamin‐K‐dependent clotting factors, suggesting an origin in some common ancestral protein.Factor X deficiency is one of the rarest of the inherited coagulation disorders. Such deficiencies are inherited in an autosomal recessive manner and are characterized by a variable bleeding tendency. In its homozygous form, factor X deficiency has an estimated prevalence of 1:500 000 but in its heterozygous form it has an estimated frequency of ∼1:500 although affected individuals are often clinically asymptomatic.Acquired deficiencies of factor X are uncommon and in isolation are seen most frequently in patients with amyloidosis and in association with upper respiratory tract infections.Treatment of the deficiency state involves factor X replacement with either fresh frozen plasma or prothrombin complex concentrates. However, the latter may be associated with an increased risk of thrombosis.
The role of the platelet function analyser (PFA‐100TM) in the characterization of patients with von Willebrand's disease and its relationships with von Willebrand factor and the ABO blood group
Authors: Nitu‐Whalley I. C. , Lee C. A. , Brown S. A. , Riddell A. , Hermans C. 
Published: December 2004

Summary.Determination of the closure time (CT) with the platelet function analyser (PFA‐100TM) is a useful screening test for von Willebrand's disease (VWD) but its role in the characterization of VWD is not well established. We studied the relationship between the prolongation of the CT with adenosine diphosphate (ADP) (CT‐ADP) and epinephrine (CT‐EPI) cartridges and the von Willebrand factor (VWF) in 53 patients with VWD. We found that a relatively small percentage of the prolongation of the CT‐ADR and CT‐ADP (16 and 29%, respectively) was determined by a reduction in VWF levels. The CT‐ADP was significantly more prolonged in the presence of qualitative defects in VWF but could not discriminate between the VWD subtypes. The ABO blood group had no effect on the prolongation of the CT or the bleeding time. In conclusion, the PFA‐100TM appears of little use in the characterization of severity and subtype of VWD.
Economic modelling of different treatment strategies for haemophilia A with high‐responding inhibitors
Authors: Knight C. , Paisley S. , Wight J. , Jones M. L. 
Published: December 2004

Summary.  This paper reports a systematic review of the cost‐effectiveness of treatment options in patients with haemophilia A with inhibitors. As very little relevant published evidence was identified, an economic modelling exercise was undertaken to calculate the cost‐effectiveness of different strategies in the treatment of high‐responding haemophilia A patients with inhibitors. A decision analysis approach was used to model the expected lifetime clinical outcomes and costs of the more common regimens currently used in UK in treating severe haemophiliacs with inhibitors.The model attempts to reflect the outcomes of clinical events, costs and life expectancy for each different treatment regimen for haemophilic boys with inhibitors who are high responders (defined as inhibitor level ≥10 BU) throughout their life. The basic model structure is centred on a Markov decision process, which was used to simulate, at quarter‐yearly intervals, the movement through discrete health states and their complications.The model allows a comparison of cost‐effectiveness between three immune tolerance induction (ITI) regimens (Bonn, Mälmo and Low‐Dose protocols) and against a relevant ‘on‐demand’ (OD) regimen. It also shows the cost‐effectiveness of different OD regimens using different bypassing agents.The results of the economic modelling indicate that treating haemophilia A patients who have high‐responding inhibitors OD with recombinant activated factor VII is cost‐effective compared to treatment with activated prothrombin complex concentrates. However, when OD treatment regimens are compared with the three ITI protocols, the Malmö ITI protocol is the preferred treatment strategy, generating more quality adjusted life‐years (QALYs) and less cost than either an OD regimen or the Bonn or Low‐Dose ITI protocols.
Transcription of purine transporter genes is activated during the isotropic growth phase of Aspergillus nidulans conidia
Authors: Amillis Sotiris , Cecchetto Gianna , Sophianopoulou Vicky , Koukaki Marina , Scazzocchio Claudio , Diallinas George 
Published: December 2004

Summary Aspergillus nidulans possesses three well‐characterized purine transporters encoded by the genes uapA, uapC and azgA. Expression of these genes in mycelium is induced by purines and repressed by ammonium or glutamine through the action of the pathway‐specific UaY regulator and the general GATA factor AreA  respectively.  Here,  we  describe  the  regulation of expression of purine transporters during conidiospore germination and the onset of mycelium development. In resting conidiospores, mRNA steady‐state levels of purine transporter genes and purine uptake activities are undetectable or very low. Both mRNA steady‐state levels and purine transport activities increase substantially during the isotropic growth phase of conidial germination. Both processes occur in the absence of purine induction and independently of the nitrogen source present in the medium. The transcriptional activator UaY is dispensable for the germination‐induced expression of the three transporter genes. AreA, on the other hand, is essential for the expression of uapA, but not for that of azgA or uapC, during germination. Transcriptional activation of uapA, uapC and azgA during germination is also independent of the presence of a carbon source in the medium. This work establishes the presence of a novel system triggering purine transporter transcription during germination. Similar results have been found in studies on the expression of other transporters in A. nidulans, suggesting that global expression of transporters might operate as a general system for sensing solute availability.
Using nominal group technique to assess chronic pain, patients' perceived challenges and needs in a community health region
Authors: Dewar Anne , White Marc , Posade Santiago T. , Dillon Wilson 
Published: December 2004

AbstractPurpose  The purpose of this study was to better understand the experiences of people suffering from chronic pain in order to plan client‐centred educational interventions.Methods  People in the community with chronic pain were invited via newspapers, newsletters and e‐mail discussion lists to participate in a needs assessment process and to attend an educational session at a local community college. Using the nominal group technique, which is a qualitative method of data gathering, 53 participants reported their perceived challenges and needs in dealing with chronic pain. Participants were randomly assigned to one of 10 groups ranging from three to seven people. Responses were pooled to develop an overall list of their major concerns and needs.Results  Issues were classified into six priority areas: medical and treatments, problems with daily living, emotional distress, social issues, sleep disturbances and financial issues. Participants indicated they had difficulty finding accessible, effective and acceptable care. Many participants perceived their family physician or other health‐care providers were not adequately meeting their health‐care needs. Specifically, sleep disorders; feeling of depression, irritability, worry and anxiety were perceived as medical and treatment areas requiring improvement. In addition, participants sought greater validation of their lived experience of chronic pain.Conclusion  Participants perceived that their needs were not being met adequately. There is a need for further study on physician–patient communication and its impact on patient health status and disability.
A note on the relative importance that people attach to different factors when setting priorities in health care
Authors: Dolan Paul , Shaw Rebecca 
Published: December 2004

AbstractObjective  To explore whether and to what extent people wish to give differential priority when asked to choose between providing health care treatment for different individuals or groups, on the basis of a range of factors, ranging from health gain to the number of dependants a person has.Design  A sample of people resident in York self‐completed a questionnaire.Setting  The City of York.Participants  Twenty‐three members of the general public and 29 undergraduate students.Main outcome measures  The relative importance of factors that people think should be taken into account when choosing between providing health care treatment for individuals or groups.Results  The results suggest that health gain and the consequences for health without treatment are two of the most important considerations.Conclusions  A sample of the general public and undergraduate students wish to take account of a number of personal characteristics when setting priorities in health care.
An approach to determining the workability diagram based on upsetting tests
Authors: VILOTIĆ D. , PLANČK M. , GRBIĆ S. , ALEXANDROV S. , CHIKANOVA N. 
Published: December 2004

ABSTRACTTo determine a workability diagram for bulk metal forming processes, it is proposed to use experiments in which fracture occurs at a free surface. A good example of such experiments is an upsetting test with profiled dies. An advantage of this method is that fracture conditions are formulated in terms of strain components whereas stresses are excluded using an exact theoretical solution. In the present study three axisymmetric upsetting tests, with flat dies and with conical dies, are carried out to determine the strain to fracture. The method proposed is then combined with these experimental data to find an approximation to the workability diagram of a tool steel.
Detection of crack nucleation in sheet metalforming by monitoring infrared radiation
Authors: ANDRIANOPOULOS N. P. , CHAMPIDIS K. T. , ILIOPOULOS A. P. 
Published: December 2004

ABSTRACTIn the present work a method is described for the early detection of large plastic strains localisation and subsequent crack nucleation in sheet metalforming. The method is based on the monitoring of the infrared radiation emitted from the material during stretching. It is concluded that the point of the final crack nucleation can be located in the very early stages of stretching, when overall mean strains are insignificant (less than 20% of the yielding strain of the material).
Definition of the kinetic equation form for damage under the plastic deformation
Authors: SMIRNOV S. V. , DOMILOVSKAYA T. V. 
Published: December 2004

ABSTRACTPlastic deformation of metals leads to the residual variation of the volume of the metal due to the appearance and growth of deformational defects. This process is known as ‘defect accumulation’. The intensity of this process depends on the metal properties and loading parameters. This work is concentrated first of all with experiments, used to set up the physically substantiated model of damage accumulation under complex stress states. A special technique allowed the loading of the specimens under various superimposed hydrostatic pressures (0.1–800 MPa) to simulate the process of damage accumulation under a wide range of stress states. The metal density was chosen as the characteristic of damage. The experiments support hypotheses of a linear dependence between the damage accumulation intensity and the controlling stress state index, and an inverse exponential dependence of the critical damage accumulation.