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1.
Carole A Estabrooks Linda Derksen Connie Winther John N Lavis Shannon D Scott Lars Wallin Joanne Profetto-McGrath 《Implementation science : IS》2008,3(1):1-22
Background
It has been argued that science and society are in the midst of a far-reaching renegotiation of the social contract between science and society, with society becoming a far more active partner in the creation of knowledge. On the one hand, new forms of knowledge production are emerging, and on the other, both science and society are experiencing a rapid acceleration in new forms of knowledge utilization. Concomitantly since the Second World War, the science underpinning the knowledge utilization field has had exponential growth. Few in-depth examinations of this field exist, and no comprehensive analyses have used bibliometric methods.Methods
Using bibliometric analysis, specifically first author co-citation analysis, our group undertook a domain analysis of the knowledge utilization field, tracing its historical development between 1945 and 2004. Our purposes were to map the historical development of knowledge utilization as a field, and to identify the changing intellectual structure of its scientific domains. We analyzed more than 5,000 articles using citation data drawn from the Web of Science®. Search terms were combinations of knowledge, research, evidence, guidelines, ideas, science, innovation, technology, information theory and use, utilization, and uptake.Results
We provide an overview of the intellectual structure and how it changed over six decades. The field does not become large enough to represent with a co-citation map until the mid-1960s. Our findings demonstrate vigorous growth from the mid-1960s through 2004, as well as the emergence of specialized domains reflecting distinct collectives of intellectual activity and thought. Until the mid-1980s, the major domains were focused on innovation diffusion, technology transfer, and knowledge utilization. Beginning slowly in the mid-1980s and then growing rapidly, a fourth scientific domain, evidence-based medicine, emerged. The field is dominated in all decades by one individual, Everett Rogers, and by one paradigm, innovation diffusion.Conclusion
We conclude that the received view that social science disciplines are in a state where no accepted set of principles or theories guide research (i.e., that they are pre-paradigmatic) could not be supported for this field. Second, we document the emergence of a new domain within the knowledge utilization field, evidence-based medicine. Third, we conclude that Everett Rogers was the dominant figure in the field and, until the emergence of evidence-based medicine, his representation of the general diffusion model was the dominant paradigm in the field. 相似文献2.
Hans Olav Ibrekk Erik Børset Erik Hauan 《Journal of Aquatic Ecosystem Stress and Recovery (Formerly Journal of Aquatic Ecosystem Health)》1993,2(1):45-53
Previously the effects of pollution abatement were measured in terms of the size of reductions achieved. This paper demonstrates a method that can be used to measure effects in relation to the practical significance of the reductions for the people living in the area concerned. The approach used in the project Locally Adapted Regulatory Impact Analysis (LARIA), aims to overcome the problem of finding a correct balance between the size and cost of the effort required in relation to the benefit to society for conservation projects. The proposed methodology consists of four parts. First, the user interests in the Lake Mjøsa basin are determined, and relative weights expressing the importance is given to the users. Then, a water quality effect model was developed. Focus is put on developing a phosphorus effect model taking into account the biological availability of phosphorus. The third step is a model to express the benefit to society from improvement in water quality. The fourth step is to identify and rank all available abatement measures using information from the effect model and the cost of implementation of each measure. 相似文献
3.
Breno Barros Telles do Carmo Manuele Margni Pierre Baptiste 《The International Journal of Life Cycle Assessment》2017,22(12):2007-2017
Purpose
In social life cycle assessment (SLCA), to measure the social performance, it is necessary to consider the subcategory indicators related to each stakeholder dimension, such as workers, local community, society, consumers and value chain participants. Current methods in SLCA scientific literature consider a standard arbitrary linear score set to translate qualitative performances into a quantitative assessment for all subcategory indicators, i.e., it translate a A, B, C, D scoring into a 4, 3, 2, 1 ordinal scale. This assumption does not cover the complexity of the subcategory indicators in the social life cycle assessment phase. The aim of this paper is to set out a customized scoring and weighting approach for impact assessment in SLCA beyond the assumption of arbitrary linearity and equal weighting.Methods
This method overcomes the linearity assumption and develops specific value functions for each subcategory indicator and an approach to establish the weighting factors between the indicators for each social dimension (workers, local community, and society). The value function and weighting factors are based on the considered opinions of SLCA experts in Québec.Results and discussion
The results show that value functions with different shapes used to score the performance of the product within each subcategory indicator influence SLCA results and have the potential to reverse the conclusions. The customized score is more realistic than the linear score because it can better capture the complexity of the subcategory indicators based on SLCA expert judgment.Conclusions
Our approach addresses a methodological weakness of the impact assessment phase of SLCA through a more representative performance of the potential social impacts based on the judgment of the SLCA expert rather than a simplified assumption of linearity and equal weighting among indicators. This approach may be applied to all types of product systems.Recommendations
The value functions and weighting factors cannot be generalized for all cases and the proposed approach must be adapted for each study. We stopped at the aggregation of the subcategory indicators based on expert judgment at the stakeholder level. If a complete aggregation in a single score is required, we recommend developing a framework that accounts for the value judgment of the decision-maker rather than the SLCA expert.4.
Objectives
We investigated the effect of a nationwide educational program following surviving sepsis campaign (SSC) guidelines. Physicians’ clinical practice in sepsis care and patient mortality rate for severe sepsis were analyzed using a nationally representative cohort.Methods
Hospitalizations for severe sepsis with organ failure from 1997 to 2008 were extracted from Taiwan’s National Health Insurance Research Database (NHIRD), and trends in sepsis incidence and mortality rates were analyzed. A before-and-after study design was used to evaluate changes in the utilization rates of SSC items and changes in severe sepsis mortality rates occurred after a national education program conducted by the Joint Taiwan Critical Care Medicine Committee since 2004. A total of 39,706 hospitalizations were analyzed, which consisted of a pre-intervention cohort of 14,848 individuals (2000-2003) and a post-intervention cohort of 24,858 individuals (2005-2008).Results
The incidence rate of severe sepsis increased from 1.88 per 1,000 individuals in 1997 to 5.07 per 1,000 individuals in 2008. The cumulative mortality rate decreased slightly from 48.2% for the pre-intervention cohort to 45.9% for the post-intervention cohort. The utilization rates of almost all SSC items changed significantly between the pre-intervention and post-intervention cohorts. These changes of utilization rates were found to be associated with mild reduction in mortality rate.Conclusion
The nationwide education program through a national professional society has a significant impact on physicians’ clinical practice and resulted in a slight but significant reduction of severe sepsis mortality rate. 相似文献5.
H. G. Landau 《Bulletin of mathematical biology》1965,27(1):151-160
A society with a dominance relation is considered to be built up by starting with a small society and adding new members in
succession. As each member is added he engages in contests with each of the older members to determine the dominance relation
between them. The probability that the older member dominates is considered to depend on the size of the society and linearly
on the older members score. A recurrence relation for the hierarchy index is derived. The approach of the society to a hierarchical
structure is considered for various special cases of this probability. Reasonable assumptions concerning this dominance probability
are shown to lead to structures close to the hierarchy. If the new member dominates all the older ones below a certain rank,
and is dominated by all those above this rank, then the hierarchy will persist if it is the initial structure, or the structure
will tend to hierarchy as the size increases, if it is not the initial structure. 相似文献
6.
Nobuo Kawamiya 《Theoretical biology forum》2003,96(3):399-431
Imanishi's "mental" (cerebral) view of speciation is presented, in Mizuhata's revision. The key concept here is the "ethological partition" of the species. Members of each species=society (etho-species) share the same mental (brain) software, irrespective of their genetic structure. Cerebral animals perform active programmed selection, not to be confused with passive, non-programmed "natural selection" as in Neo-Darwinism. The program includes mating-choice of peculiar characters, distinct from the Neo-Darwinian sexual selection supposed due to the specific choosy genes. Speciation can occur, as a "partition of species=society", with bifurcation of mate-choosing program in the parent species. A main promoter for this bifurcation is species-specific "passion" for especially significant characters: long necks, ornamental antlers, ocelli feathers, bright nuptial colors etc. The cichlids in Lake Victoria achieved explosive speciation, while retaining their genetic homogeneity completely. Therefore it is illogical to attribute this divergence to extraordinary mutations in "action controlling genes". The origin of species=society (etho-species) can trace along to the Cambrian Period. 相似文献
7.
8.
Objectives
To report on and examine differences in the use of four types of rehabilitation services (occupational therapy, physiotherapy, psychology, and speech therapy) by men and women following a work-related traumatic brain injury in Victoria, Australia; and to examine the importance of demographic, need, work-related and geographic factors in explaining these differences.Methods
A retrospective cohort design was used to analyze 1786 work-related traumatic brain injury workers’ compensation claims lodged between 2004 and 2012 in Victoria, Australia. ZINB regressions were conducted for each type of rehabilitation service to examine the relationship between sex and rehabilitation use. Covariates included demographic, need-related, work-related, and geographic factors.Results
Out of all claims (63% male, 37% female), 13% used occupational therapy, 23% used physiotherapy, 9% used psychology, and 2% used speech therapy at least once during the first year of service utilization. After controlling for demographic, need-related, work-related, and geographic factors, women were more likely to use physiotherapy compared to men. Men and women were equally likely to use occupational therapy and psychology services. The number of visits in the first year for each type of service did not differ between male and female users.Conclusions
Our findings support a sex-based approach to studying rehabilitation utilization in work-related populations. Future research is needed to examine other factors associated with rehabilitation utilization and to determine the implications of different rehabilitation utilization patterns on health and return-to-work outcomes. 相似文献9.
Niche Shape and Genetic Aspects of Character Displacement 总被引:1,自引:0,他引:1
Character displacement involving a single, diallelic locus ineach of two competing species is investigated via computer simulation.The niche, as the sum of the utilization efficiencies of thepopulation for combinations of environmental variables, is distinguishedfrom the resource peak, which is a set of combinations of environmentalvariables actually present at exploitable frequencies in theenvironment. The two populations compete for a single resourcepeak made up of five subunits. Each genotype in each specieshas an optimum peak subunit, but survives in all of them. Theintermediate subunit is optimal for a genotype in each species.Movement is restricted between subunits, which are thus treatedhere as microhabitats. The simulation covers a geographicalrange with each species occurring alone where its birth rateis high, with the birth rate declining as the range of the otherspecies is approached; sympatry occurs in a region of intermediatebirth rates for both species. The character displacement involvescharacters determined by the genotypes at the competition locus.The shape of the resource peak has a profund effect on the formtaken by character displacement. A "steep" peak (one with theintermediate subunit much more frequent than the rest) resultsin a sharp step in the morphoclines, with two stable equilibriumpoints at the point of equal birth rates. A "bimodal" peak (onewith equally frequent subunits, each optimum for a genotypefor one species only) leads to a gradual change. Other peaktypes also have characteristic effects, showing that ecologicalinferences can be drawn from the form taken by character displacement. 相似文献
10.
海洋生态环境保持健康状态是人类可持续开发利用海洋资源环境的基础,而近海海洋生态环境的健康状况综合评价可为海洋生态环境良性发展以及社会经济决策提供科学依据。首先对国际上3种代表性的海洋环境健康综合评价方法的应用特点进行了对比分析,并归纳了我国海洋生态环境健康评价的状况,在此基础上,以指标体系法重构了一个双核结构的综合评价框架,其中内核评价以海洋生态系统的自身状态为主,外核评价则主要反映海洋之于人类经济社会的贡献,以期能够科学、准确、全面的评价我国近海海洋环境健康状况。 相似文献
11.
Yamamoto K 《Collegium antropologicum》2002,26(2):695-709
According to Plato, the society as reflected in Homer's epics is one without state power. In a society without state power, the act of revenge which the offended party prosecutes on the offender is the only disciplinary force, which should be endorsed by the ethical concepts of the society. Though the ethics of Homeric society has been analyzed before, there has been no theory on the ethical structure of Homeric society analyzed from the viewpoint of a society without state power. This study attempts to address this issue. Six concepts, "oath", "honor", "guest", "blood", "food" and "revenge" have been extracted from Homeric epics in comparison with the ethical structure of the Albanian Kanun. The ethical structure of Homeric society appears to belong to the category of the ethics of a society without state power, as represented by the ethical structure of the Kanun. Plato explicitly criticizes the ethical value system of Homeric society, which he thinks is alienated from the idea of Good. 相似文献
12.
Background
There is currently a steady increase in the use of wood-based fuels for heat and power production in Sweden. A major proportion of these fuels could serve as feedstock for ethanol production. In this study various options for the utilization of the solid residue formed during ethanol production from spruce, such as the production of pellets, electricity and heat for district heating, were compared in terms of overall energy efficiency and production cost. The effects of changes in the process performance, such as variations in the ethanol yield and/or the energy demand, were also studied. The process was based on SO2-catalysed steam pretreatment, which was followed by simultaneous saccharification and fermentation. A model including all the major process steps was implemented in the commercial flow-sheeting program Aspen Plus, the model input was based on data recently obtained on lab scale or in a process development unit.Results
For the five base case scenarios presented in the paper the overall energy efficiency ranged from 53 to 92%, based on the lower heating values, and a minimum ethanol selling price from 3.87 to 4.73 Swedish kronor per litre (0.41–0.50 EUR/L); however, ethanol production was performed in essentially the same way in each base case scenario. (Highly realistic) improvements in the ethanol yield and reductions in the energy demand resulted in significantly lower production costs for all scenarios.Conclusion
Although ethanol was shown to be the main product, i.e. yielding the major part of the income, the co-product revenue had a considerable effect on the process economics and the importance of good utilization of the entire feedstock was clearly shown. With the assumed prices of the co-products, utilization of the excess solid residue for heat and power production was highly economically favourable. The study also showed that improvements in the ethanol yield and reductions in the energy demand resulted in significant production cost reductions almost independently of each other. 相似文献13.
Background
In 2009 the state government of Madhya Pradesh, India launched an emergency obstetric transportation service, Janani Express Yojana (JEY), to support the cash transfer program that promotes institutional delivery. JEY, a large scale public private partnership, lowers geographical access barriers to facility based care. The state contracts and pays private agencies to provide emergency transportation at no cost to the user. The objective was to study (a) the utilization of JEY among women delivering in health facilities, (b) factors associated with usage, (c) the timeliness of the service.Methods
A cross sectional facility based study was conducted in facilities that carried out > ten deliveries a month. Researchers who spent five days in each facility administered a questionnaire to all women who gave birth there to elicit socio-demographic characteristics and transport related details.Results
35% of women utilised JEY to reach a facility, however utilization varied between study districts. Uptake was highest among women from rural areas (44%), scheduled tribes (55%), and poorly educated women (40%). Living in rural areas and belonging to scheduled tribes were significant predictors for JEY usage. Almost 1/3 of JEY users (n = 104) experienced a transport related delay.Discussion
The JEY service model complements the cash transfer program by providing transport to a facility to give birth. A study of the distribution of utilization in population subgroups suggests the intervention was successful in reaching the most vulnerable population, promoting equity in access. While 1/3 of women utilized the service and it saved them money; 30% experienced significant transport related delays in reaching a facility, which is comparable to women using public transportation. Further research is needed to understand why utilization is low, to explore if there is a need for service expansion at the community level and to improve the overall time efficiency of JEY. 相似文献14.
Shiu-Dong Chung Shih-Ping Liu Jau-Jiuan Sheu Ching-Chun Lin Herng-Ching Lin Chao-Hung Chen 《PloS one》2014,9(8)
Background
The majority of previous studies investigating the health care utilization of people with dementia were conducted in Western societies. There is little information on the economic burden on the healthcare system attributable to dementia in Asian countries. This study thus investigated differences in utilization of healthcare services between subjects with and those without a diagnosis of dementia using Taiwan’s National Health Insurance population-based database.Methods
This study comprised 5,666 subjects with a dementia diagnosis and 5,666 age- and gender-matched comparison subjects without a dementia diagnosis. We individually followed each subject for a 1-year period starting from their index date to evaluate their healthcare resource utilization. Healthcare resource utilization included the number of outpatient visits and inpatient days, and the mean costs of outpatient and inpatient treatments. In addition, we divided healthcare resource utilization into psychiatric and non-psychiatric services.Results
As for utilization of psychiatric services, subjects with a dementia diagnosis had significantly more outpatient visits (2.2 vs. 0.3, p<0.001) and significantly higher outpatient costs (US$124 vs. US$16, p<0.001) than comparison subjects. For non-psychiatric services, subjects with a dementia diagnosis also had significantly more outpatient visits (34.4 vs. 31.6, p<0.001) and significantly higher outpatient costs (US$1754 vs. US$1322, p<0.001) than comparison subjects. For all healthcare services, subjects with a dementia diagnosis had significantly more outpatient visits (36.7 vs. 32.0, p<0.001) and significantly higher outpatient costs (US$1878 vs. US$1338, p<0.001) than comparison subjects. Furthermore, the total cost was about 2-fold greater for subjects with a dementia diagnosis than for comparison subjects (US$3997 vs. US$2409, p<0.001).Conclusions
We concluded that subjects who had received a clinical dementia diagnosis had significantly higher utilization of all healthcare services than comparison subjects. 相似文献15.
中国生态地理区城市水资源利用效率时空分异特征 总被引:6,自引:0,他引:6
我国水资源面临的形势十分严峻,水资源短缺、水污染严重、水生态环境恶化等问题突出,已成为制约社会经济可持续发展的主要瓶颈。基于分类数据包络分析(Categorical DEA)对2007-2016年中国生态地理区城市水资源利用效率进行测算,对其时间变化、空间分布以及空间收敛性进行分析。结果表明:1)2007-2016年期间全国城市水资源利用效率总体处于低效率状态,随时间高低交错波动式发展,整体呈先降后升势态;2)生态地理区城市水资源利用综合效率由高到低依次为温带干旱区、温带半干旱区、温带半湿润区、温带湿润区、亚热带湿润区,呈西北向东南逐渐递减的空间分布格局,生态地理区纯技术效率区间差异较大,但空间分布规律不显著,区域规模效率间差距小,且无明显空间分布规律;3)纯技术效率低效是制约全国水资源利用综合效率提升的主要因素,生态地理区间纯技术效率巨大差距导致全国纯技术效率整体低效,也是全国水资源利用综合效率低效的根本原因;4)生态地理区水资源利用综合效率区域差距逐渐缩小,主要是因为高效率区域效率值向低效率区域靠拢,区域间低效向高效的"追赶效应"不明显。 相似文献
16.
Disagreement exists concerning the nature of relations between the sexes in foraging societies. The crucial issue concerns the quality of interactions across rather than within sexual boundaries. Approaching the problem in terms of a political analysis allows cross-cultural comparisons utilizing behavioral data. While all foraging societies are egalitarian within sexual boundaries, not all are egalitarian across sexual boundaries. The analytic usefulness of two subtypes of egalitarian society, the "pure-egalitarian" and the "semi-egalitarian," is suggested . [sexual politics, egalitarian societies, status of women, hunters and gatherers] 相似文献
17.
James E. Stahl Michelle L. Dossett A. Scott LaJoie John W. Denninger Darshan H. Mehta Roberta Goldman Gregory L. Fricchione Herbert Benson 《PloS one》2015,10(10)
Background
Poor psychological and physical resilience in response to stress drives a great deal of health care utilization. Mind-body interventions can reduce stress and build resiliency. The rationale for this study is therefore to estimate the effect of mind-body interventions on healthcare utilization.Objective
Estimate the effect of mind body training, specifically, the Relaxation Response Resiliency Program (3RP) on healthcare utilization.Design
Retrospective controlled cohort observational study. Setting: Major US Academic Health Network. Sample: All patients receiving 3RP at the MGH Benson-Henry Institute from 1/12/2006 to 7/1/2014 (n = 4452), controls (n = 13149) followed for a median of 4.2 years (.85–8.4 yrs). Measurements: Utilization as measured by billable encounters/year (be/yr) stratified by encounter type: clinical, imaging, laboratory and procedural, by class of chief complaint: e.g., Cardiovascular, and by site of care delivery, e.g., Emergency Department. Subgroup analysis by propensity score matched pre-intervention utilization rate.Results
At one year, total utilization for the intervention group decreased by 43% [53.5 to 30.5 be/yr] (p <0.0001). Clinical encounters decreased by 41.9% [40 to 23.2 be/yr], imaging by 50.3% [11.5 to 5.7 be/yr], lab encounters by 43.5% [9.8 to 5.6], and procedures by 21.4% [2.2 to 1.7 be/yr], all p < 0.01. The intervention group’s Emergency department (ED) visits decreased from 3.6 to 1.7/year (p<0.0001) and Hospital and Urgent care visits converged with the controls. Subgroup analysis (identically matched initial utilization rates—Intervention group: high utilizing controls) showed the intervention group significantly reduced utilization relative to the control group by: 18.3% across all functional categories, 24.7% across all site categories and 25.3% across all clinical categories.Conclusion
Mind body interventions such as 3RP have the potential to substantially reduce healthcare utilization at relatively low cost and thus can serve as key components in any population health and health care delivery system. 相似文献18.
Modulation of the cryopreservation cap: elevated survival with reduced dimethyl sulfoxide concentration 总被引:4,自引:0,他引:4
The development of cryopreservation (CP) strategies has traditionally focused on the cellular chemo-osmometric characteristics attendant to the freeze-thaw process. This approach coupled with a limited understanding of cellular physiological and biochemical responses to the CP process often yields sub-optimal cell survival. Recently, we have reported on the benefits of the utilization of an intracellular-like preservation solution, HypoThermosol (HTS), as well as incorporating a molecular approach to improving CP outcome [In Vitro Cell. Dev. Biol. Anim. 36(4) (2000) 262]. We now report on the elucidation of a cryoprotective agent (CPA)-dependent survival limit (cap) associated with standard CP methodologies. We further demonstrate an elevation and shift in the CP cap through the utilization of HTS coupled with a reduction in CPA levels necessary to achieve "successful" cell preservation. METHODS: Human fibroblasts, keratinocytes, hepatic, and renal cells were cryopreserved in a standard fashion (approximately 1 degrees C min-1 cooling and storage in LN2) in culture media (serum-free) or HTS with varying levels of dimethyl sulfoxide (Me2SO). Samples were allowed to recover for 24-h prior to survival assessment. Survival was assessed using alamarBlue (metabolic activity indicator) and calcien-AM (membrane integrity stain) in comparison with non-frozen controls. RESULTS: (1) A limit in cell survival was identified following CP in media-based CP solutions yielding a cell-type specific CPA-dependent survival limit, (2) peak cell survival resulted in the identification of "optimal" Me2SO concentrations for CP of each cell type, (3) incorporation of HTS as the carrier medium at typical Me2SO concentrations substantially elevated survival, and (4) utilization of HTS allowed for the successful preservation of all systems examined at significantly reduced Me2SO levels. CONCLUSION: The data presented in this study illustrate that the utilization of HTS as the carrier medium during CP facilitated a significant improvement in efficacy at reduced Me2SO levels. Further, the utilization of HTS offers the potential for successful Me2SO-free CP. These findings may prove significant to the advancement in the development of cell-based clinical therapies by providing an improved biocompatible CP methodology. 相似文献
19.
Background
Selenium (Se) and sulfur (S) are closely related elements that exhibit similar chemical properties. Some genes related to S metabolism are also involved in Se utilization in many organisms. However, the evolutionary relationship between the two utilization traits is unclear.Results
In this study, we conducted a comparative analysis of the selenophosphate synthetase (SelD) family, a key protein for all known Se utilization traits, in all sequenced archaea. Our search showed a very limited distribution of SelD and Se utilization in this kingdom. Interestingly, a SelD-like protein was detected in two orders of Crenarchaeota: Sulfolobales and Thermoproteales. Sequence and phylogenetic analyses revealed that SelD-like protein contains the same domain and conserved functional residues as those of SelD, and might be involved in S metabolism in these S-reducing organisms. Further genome-wide analysis of patterns of gene occurrence in different thermoproteales suggested that several genes, including SirA-like, Prx-like and adenylylsulfate reductase, were strongly related to SelD-like gene. Based on these findings, we proposed a simple model wherein SelD-like may play an important role in the biosynthesis of certain thiophosphate compound.Conclusions
Our data suggest novel genes involved in S metabolism in hyperthermophilic S-reducing archaea, and may provide a new window for understanding the complex relationship between Se and S metabolism in archaea.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-908) contains supplementary material, which is available to authorized users. 相似文献20.
The purpose of this study was (i) to evaluate biomass productionand nitrogen utilization in grey alder and (ii) to investigatecarbon utilization in alders fixing nitrogen or supplied withnitrate. Two experiments were made, each using two groups ofalders (Alnus incana (L.) Moench) growing in a climate chamber.In each experiment one group was inoculated with a local sourceof Frankia. The other group was not inoculated but receivednitrate in the same amount as the first group fixed nitrogen.Therefore, the rate of nitrate application increased duringthe experimental period. Biomass production, growth, nitrogencontent and nitrogen utilization were determined in one experiment.Growth, nitrate reductase activity, net photosynthesis and rootrespiration were measured in the second experiment. In experimentone there was no significant difference in biomass productionbetween the two groups of plants. Of the nitrate given 99% wastaken up and 1% of this uptake was excreted in an organic form.In the second experiment the plant development was similar innodulated and non-nodulated alders during the period studied.Nitrate reductase activity was found in both root- and shoot-tipsof the non-nodulated alders. At both days 24 and 30, the amountof carbon respired compared to the amount of carbon assimilatedwas similar for the nodulated alders as for the non-nodulatedalders. As nitrogen fixation increased, photosynthesis alsoincreased. Thus, there was an inter-relationship between netphotosynthesis and nitrogen fixation. Key words: Alnus-Frankia symbioses, carbon utilization, nitrogen (N2 ) utilization 相似文献