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1.
Med Health Care Philos ; 26(2): 163-173, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36780061

ABSTRACT

In the initial phase of the COVID-19 pandemic, Sweden's response stood out as an exception. For example, Sweden did not introduce any lockdowns, while many other countries did. In this paper I take the Swedish Corona Commission's critique of the initial Swedish response as a point of departure for a general analysis of precaution in relation to pandemics. The Commission points out that in contrast to many other countries Sweden did not follow 'the precautionary principle'. Based on this critique, the Commission proposes that the precautionary principle should be included among Sweden's guiding principles for crisis management. However, as the debate on this principle during the last 30 years indicates, the principle is loaded with problems. I discuss one of these problems, namely its lack of clarity. I argue, however, that this problem is not unsurmountable. A principle is lacking clarity precisely by being a principle and not a rule with a well-defined meaning. As a principle it indicates a direction but does not prescribe a specific action. However, to be action-guiding its content needs to be specified by rational deliberation. With this in mind, I propose a framework for specification of the precautionary principle as applied to pandemics. The framework focuses on the principle's four key elements: threat, uncertainty, action and responsibility. I also suggest certain general ethical restrictions on specification.


Subject(s)
COVID-19 , Pandemics , Humans , Sweden/epidemiology , Risk Assessment , COVID-19/epidemiology , COVID-19/prevention & control , Communicable Disease Control
2.
J Agric Environ Ethics ; 34(4): 22, 2021.
Article in English | MEDLINE | ID: mdl-34257508

ABSTRACT

In the debate on climate change commentators often express pessimistic or optimistic views. We see this mainly in the media and popular literature, but also in various academic fields. The aim of this paper is to investigate different kinds of pessimistic and optimistic views put forward in this debate and suggest explanations of the diversity of views. The paper concludes that pessimism and optimism may concern, for example, climate change as an unmitigated or poorly mitigated process, mitigation of climate change or specific measures of mitigation. These aspects are important to distinguish, because a person can be pessimist concerning climate change as an unmitigated or poorly mitigated process and optimist concerning mitigation of climate change, and be pessimist concerning one specific mitigation measure and optimist concerning another. It is suggested that the diversity of pessimistic and optimistic views is due to the uncertainty of scientific climate models and the influence of evaluative and ideological assumptions.

3.
J Bioeth Inq ; 16(4): 559-570, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31755017

ABSTRACT

Human germline gene editing is often debated in hypothetical terms: if it were safe and efficient, on what further conditions would it then be ethically acceptable? This paper takes another course. The key question is: how can scientists reduce uncertainty about safety and efficiency to a level that may justify initiation of first-time clinical trials? The only way to proceed is by well-designed preclinical studies. However, what kinds of investigation should preclinical studies include and what specific conditions should they satisfy in order to be considered well-designed? It is argued that multispecies and multigenerational animal studies are needed as well as human embryo editing without implantation. In order to be possible to translate to first-time clinical trials, animal studies need to satisfy strict conditions of validity. Moreover, embryo studies intended for translation to first-time clinical trials need to correspond to the animal studies in experimental design (with exception of implantation). Only in this way can uncertainty about risk for harm (safety) and prospect of benefit (efficiency) in first-time clinical trials be reduced to a modest level. If uncertainty is not reduced to such a level, first-time clinical trials in germline gene editing should not be initiated.


Subject(s)
Drug Evaluation, Preclinical/ethics , Embryo Research/ethics , Gene Editing/ethics , Animals , Drug Evaluation, Preclinical/methods , Germ Cells , Humans , Reproducibility of Results , Risk Assessment , Uncertainty
4.
Med Health Care Philos ; 21(3): 411-421, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29214555

ABSTRACT

It is a common experience among care professionals that persons with dementia often say 'no' to conventional caring measures such as taking medication, eating or having a shower. This tendency to say 'no' may also concern the use of assistive technologies such as fall detectors, mobile safety alarms, Internet for social contact and robots. This paper provides practical recommendations for care professionals in home health care and social care about how to respond to such resistiveness towards assistive technologies. Apart from the option of accepting the 'no', it discusses a number of methods for influencing persons with dementia in order to overcome the 'no'. These methods range from various non-coercive measures-including nudging-to coercion. It is argued that while conventional caring measures like those mentioned are essential for survival, health or hygiene, assistive technologies are commonly merely potentially beneficial supplements. With this in mind, it is concluded that care professionals should be more restrictive in using methods of influence involving some degree of pressure regarding assistive technologies than regarding conventional caring measures.


Subject(s)
Dementia/psychology , Home Care Services/organization & administration , Self-Help Devices , Humans , Hygiene , Philosophy, Medical
5.
Med Health Care Philos ; 19(4): 569-579, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27053223

ABSTRACT

Chronobiologists argue that their scientific findings have implications for prevention of sleep problems. They claim that some sleep problems are caused by the fact that people live against their individual body clock rather than adjusted to it. They also claim that by taking the findings of chronobiology seriously in policy-making some sleep problems can be prevented. I investigate applications of chronobiology in two social areas-school schedules and shift work-and show that in order for these applications to be justified certain implicit presumptions have to be justified. The first presumption is explanatory, namely that a chronobiological explanation is an adequate explanation of the sleep problems at hand. In addition I analyse three ethical presumptions. The first ethical presumption is that sleep is of vital value. The second is that sleep is not an exclusively private issue. The third ethical presumption is that the preventive measures to be undertaken are ethically acceptable. My main point is that it is not possible to simply "read off" policy measures from the empirical findings of chronobiology.


Subject(s)
Biological Clocks/genetics , Genes/physiology , Sleep Wake Disorders/genetics , Chronobiology Phenomena/genetics , Health Policy , Humans , Sleep Wake Disorders/prevention & control
6.
Health Care Anal ; 23(2): 148-64, 2015 Jun.
Article in English | MEDLINE | ID: mdl-23978898

ABSTRACT

The concept of privacy by design is becoming increasingly popular among regulators of information and communications technologies. This paper aims at analysing and discussing the ethical implications of this concept for personal health monitoring. I assume a privacy theory of restricted access and limited control. On the basis of this theory, I suggest a version of the concept of privacy by design that constitutes a middle road between what I call broad privacy by design and narrow privacy by design. The key feature of this approach is that it attempts to balance automated privacy protection and autonomously chosen privacy protection in a way that is context-sensitive. In personal health monitoring, this approach implies that in some contexts like medication assistance and monitoring of specific health parameters one single automatic option is legitimate, while in some other contexts, for example monitoring in which relatives are receivers of health-relevant information rather than health care professionals, a multi-choice approach stressing autonomy is warranted.


Subject(s)
Confidentiality , Health Records, Personal/ethics , Privacy , Confidentiality/ethics , Disclosure/standards , Humans
7.
Health Care Anal ; 22(4): 325-39, 2014 Dec.
Article in English | MEDLINE | ID: mdl-22802012

ABSTRACT

The proportion of elderly in society is growing rapidly, leading to increasing health care costs. New remote monitoring technologies are expected to lower these costs by reducing the number of close encounters with health care professionals, for example the number of visits to health care centres. In this paper, I discuss issues of priority setting raised by this expectation. As a starting-point, I analyse the recent debate on principles for priority setting in Sweden. The Swedish debate illustrates that developing an approach to priority setting is an ongoing process. On the basis of this analysis, I conclude that several different ethical principles, and specifications of these principles, can be appealed to for giving priority--over close encounters--to a large-scale introduction of remote monitoring technologies in health care services to elderly people, but also that many specifications can be appealed to against giving such priority. I propose that given the different views on principles, it is necessary to develop fair procedures of deliberation on these principles and their application, in particular in order to reach agreement on exactly how much resources should be allocated to remote monitoring and how much to close encounters. I also present a few points to consider in a large-scale introduction of remote monitoring.


Subject(s)
Health Priorities/ethics , Telemedicine/ethics , Aged , Cost-Benefit Analysis , Health Services Accessibility/ethics , Humans , Resource Allocation , Sweden , Telemedicine/economics
8.
J Community Genet ; 5(1): 59-68, 2014 Jan.
Article in English | MEDLINE | ID: mdl-22477021

ABSTRACT

In this paper, I investigate ethical and policy aspects of the genetic services and web-rhetoric of companies offering genetic information direct to consumer, and I do so with a special focus on genetic risk information. On their websites, the companies stress that genetic risk testing for multifactorial complex medical conditions such as cardiovascular disease and cancer may empower the consumer and provide valuable input to personal identity. Critics maintain, on the other hand, that testing can be psychologically harmful, is of limited clinical and preventive value, and vulnerable to misinterpretation. I stress the importance of empirical studies in assessing the pros and cons of direct-to-consumer testing and point out that recent empirical studies indicate that this testing is neither as harmful as feared by critics nor as empowering as promised by the companies. However, the testing is not entirely harmless. Remaining problems include testing of third parties without consent and ownership of genotypic and phenotypic information. Moreover, the testing, although not particularly empowering, may still provide input to self-understanding that some people find valuable. Regarding policy-making, I suggest that self-regulation in terms of best practice guidelines may play an important role, but I also stress that national and international regulation may be necessary.

9.
J Empir Res Hum Res Ethics ; 9(4): 1-9, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25747292

ABSTRACT

There are an increasing number of medical research studies involving children, including many long-term birth cohort studies. Involving children raises many issues, and little is known about children's own views. This study explored children's views (N = 5,851) on participation in a long-term screening study for type 1 diabetes. The results show that children 10 to 13 years of age have in general a positive attitude to pediatric research and emphasized trust in researchers. The children stressed the importance to receive information and to be involved in decisions. The children also reported feeling concerned about blood sampling and disease risk. Researchers involved in long-term pediatric research need to address these issues to promote involvement and decrease worry.


Subject(s)
Attitude , Diabetes Mellitus, Type 1 , Mass Screening , Research Subjects , Research , Adolescent , Child , Cohort Studies , Diabetes Mellitus, Type 1/diagnosis , Emotions , Female , Humans , Longitudinal Studies , Male , Patient Participation , Research Subjects/psychology , Trust
10.
Stud Health Technol Inform ; 187: 105-14, 2013.
Article in English | MEDLINE | ID: mdl-23920461

ABSTRACT

Novel care-technologies possess a transformational potential. Future care and support may be provided via monitoring technologies such as smart devices, sensors, actors (robots) and Information and Communication Technologies. Such technologies enable care provision outside traditional care institutions, for instance in the homes of patients. Health monitoring may become "personalized" i.e. tailored to the needs of individual care recipients' but may also alter relations between care providers and care recipents, shape and form the care environment and influence values central to health-care. Starting out from a social constructivist theory of technology, an interactive ethical assessment-model is offered. The suggested model supplements a traditional analysis based on normative ethical theory (top-down approach) with interviews including relevant stakeholders (a bottom-up approach). This method has been piloted by small-scale interviews encircling stakeholder perspectives on three emerging technologies: (1) Careousel, a smart medicine-management device, (2) Robot Giraff, an interactive and mobile communication-device and (3) I-Care, a care-software that combines alarm and register system. By incorporating stakeholder perspectives into the analysis, the interactive ethical assessment model provides a richer understanding of the impact of PHM-technologies on ethical values than a traditional top-down model. If the assessment is conducted before the technology has reached the market - preferably in close interaction with developers and users - ethically sound technologies may be obtained.


Subject(s)
Biomedical Technology/ethics , Confidentiality/ethics , Diagnostic Self Evaluation , Ethical Analysis/methods , Medical Informatics/ethics , Monitoring, Ambulatory/ethics , Telemedicine/ethics , Biomedical Technology/standards , Confidentiality/standards , Medical Informatics/standards , Monitoring, Ambulatory/standards , Outcome Assessment, Health Care/methods , Outcome Assessment, Health Care/standards , Practice Guidelines as Topic , Telemedicine/standards
11.
Genes Nutr ; 8(4): 349-55, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23471853

ABSTRACT

Consumers often have a positive attitude to the option of receiving personalized nutrition advice based upon genetic testing, since the prospect of enhancing or maintaining one's health can be perceived as empowering. Current direct-to-consumer services over the Internet, however, suffer from a questionable level of truthfulness and consumer protection, in addition to an imbalance between far-reaching promises and contrasting disclaimers. Psychological and behavioral studies indicate that consumer acceptance of a new technology is primarily explained by the end user's rational and emotional interpretation as well as moral beliefs. Results from such studies indicate that personalized nutrition must create true value for the consumer. Also, the freedom to choose is crucial for consumer acceptance. From an ethical point of view, consumer protection is crucial, and caution must be exercised when putting nutrigenomic-based tests and advice services on the market. Current Internet offerings appear to reveal a need to further guaranty legal certainty by ensuring privacy, consumer protection and safety. Personalized nutrition services are on the borderline between nutrition and medicine. Current regulation of this area is incomplete and undergoing development. This situation entails the necessity for carefully assessing and developing existing rules that safeguard fundamental rights and data protection while taking into account the sensitivity of data, the risks posed by each step in their processing, and sufficient guarantees for consumers against potential misuse.

12.
Health Care Anal ; 20(2): 103-18, 2012 Jun.
Article in English | MEDLINE | ID: mdl-21553006

ABSTRACT

In this paper I investigate the web-rhetoric of companies offering home-based personal health monitoring to patients and elderly people. Two main rhetorical methods are found, namely a reference to practical benefits and a use of prestige words like "quality of life" and "independence". I interpret the practical benefits in terms of instrumental values and the prestige words in terms of final values. I also reconstruct the arguments on the websites in terms of six different types of argument. Finally, I articulate a general critique of the arguments, namely that the websites neglect the context of use of personal health monitoring technologies. Whether or not a technology is good depends on the use of the technology by a particular individual in a particular context. The technology is not good-or bad-in itself. I support this critique with a number of more specific arguments such as the risk for reduced personal contact. For some elderly people social contact with care providers is more valuable than the independent living made possible by remote monitoring, for others independence is more important.


Subject(s)
Health Services , Monitoring, Ambulatory/methods , Private Sector , Telemedicine/methods , Advertising , Aged , Biomedical Technology , Health Services for the Aged , Humans , Internet , Terminology as Topic
13.
J Empir Res Hum Res Ethics ; 6(4): 68-75, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22228061

ABSTRACT

The participation of children in medical research raises many ethical issues, in particular regarding assent. However, little is known about children's own views on participation. This study presents results from interviews with children 10-12 years old with and without experience in a large-scale longitudinal screening study. We identified five themes: (1) knowledge about research, (2) a sense of altruism, (3) shared decision-making and right to dissent, (4) notions of integrity, privacy, and access, and (5) understanding of disease risk and personal responsibilities. We conclude that the children feel positive towards medical research, and want to take an active part in decisions and have their integrity respected. However, the study also indicates that children who had participated in longitudinal screening had a limited understanding, suggesting the vital importance of providing information appropriate to their age and maturity. This information should be provided out of respect for the children as persons, but also to promote their willingness to continue participating in longitudinal studies.


Subject(s)
Biomedical Research/ethics , Decision Making , Health Knowledge, Attitudes, Practice , Informed Consent By Minors , Patient Selection , Research Subjects , Altruism , Child , Comprehension , Female , Human Rights , Humans , Interviews as Topic , Longitudinal Studies , Male , Personal Autonomy , Risk , Social Responsibility
14.
Drug Metab Dispos ; 36(8): 1519-28, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18458048

ABSTRACT

The direct thrombin inhibitor melagatran is formed from ximelagatran via two intermediate metabolites, OH-melagatran and ethylmelagatran. The biotransformation of ximelagatran does not involve cytochrome P450 isoenzymes, and it has been suggested that a reported interaction with erythromycin may instead be mediated by transport proteins. A pig model that simultaneously enables bile collection, sampling from three blood vessels and perfusion of a jejunal segment, was used to investigate the biotransformation of ximelagatran and the effect of erythromycin on the intestinal and hepatobiliary transport of ximelagatran and its metabolites. The pigs received enteral ximelagatran (n = 6), enteral ximelagatran together with erythromycin (n = 6), i.v. ximelagatran (n = 4), or i.v. melagatran (n = 4). The plasma exposure of the intermediates was found to depend on the route of ximelagatran administration. Erythromycin increased the area under the plasma concentration-time curve (AUC) of melagatran by 45% and reduced its biliary clearance from 3.0 +/- 1.3 to 1.5 +/- 1.1 ml/min/kg. Extensive biliary exposure of melagatran and ethylmelagatran, mediated by active transport, was evident from the 100- and 1000-fold greater AUC, respectively, in bile than in plasma. Intestinal efflux transporters seemed to be of minor importance for the disposition of ximelagatran and its metabolites considering the high estimated f(abs) of ximelagatran (80 +/- 20%) and the negligible amount of the compounds excreted in the perfused intestinal segment. These findings suggest that transporters located at the sinusoidal and/or canalicular membranes of hepatocytes determine the hepatic disposition of ximelagatran and its metabolites, and are likely to mediate the ximelagatran-erythromycin pharmacokinetic interaction.


Subject(s)
Anticoagulants/pharmacokinetics , Azetidines/pharmacokinetics , Benzylamines/pharmacokinetics , Biliary Tract/metabolism , Intestinal Mucosa/metabolism , Liver/metabolism , Animals , Anticoagulants/administration & dosage , Anticoagulants/metabolism , Area Under Curve , Azetidines/administration & dosage , Azetidines/metabolism , Benzylamines/administration & dosage , Benzylamines/metabolism , Biotransformation , Swine
15.
Community Genet ; 11(5): 252-66, 2008.
Article in English | MEDLINE | ID: mdl-18493123

ABSTRACT

For the last 20 years the concepts of identity and identification have been subject to much interest in the humanities and social sciences. However, the implications of genetics for identity and identification have been largely neglected. In this paper, I distinguish various conceptions of identity (as continuity over time, as basic kind of being, as unique set of properties, and as social role) and identification (as subjective experience of identity in various senses and as social ascription of identity in various senses), and investigate systematically genetic perspectives on each of these conceptions. I stress the importance of taking the genetic perspectives seriously but also their limitations. In particular, I pinpoint conceptual problems that arise when a genetic approach to identity is adopted.


Subject(s)
DNA/genetics , Genetics, Medical , Social Identification , DNA Fingerprinting , Humans , Identity Crisis
16.
Reprod Biomed Online ; 13(2): 278-83, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16895647

ABSTRACT

Human reproductive cloning is a much disputed ethical issue. This technology is often condemned as being contrary to human dignity. However, there are also risk arguments. An ethical argument that is often put forward by scientists but seldom developed in more detail focuses on health risks in animal cloning. There is a high risk that animal clones exhibit abnormalities and these are increasingly believed to be due to errors in epigenetic reprogramming. The argument is that human reproductive cloning should not be carried out because human clones are also likely to exhibit abnormalities due to inappropriate epigenetic reprogramming. Different versions of this epigenetic argument are analysed, a categorical version and a non-categorical. The non-categorical version is suggested to be more well-considered. With regard to policy making on human reproductive cloning, the categorical version can be used to prescribe a permanent ban, while the non-categorical version can be used to prescribe a temporary ban. The implications of the precautionary principle--as interpreted in the European Union--are investigated. The conclusion is that it seems possible to support a temporary ban by reference to this principle.


Subject(s)
Cloning, Organism/ethics , Epigenesis, Genetic , Animals , Cloning, Organism/legislation & jurisprudence , Cloning, Organism/methods , Humans , Risk Factors
17.
Environ Sci Technol ; 40(13): 4145-50, 2006 Jul 01.
Article in English | MEDLINE | ID: mdl-16856729

ABSTRACT

Sorption may affect the bioavailability and biodegradation of pesticides in soils. The aim of this study was to test the effect of surface sorption on microbial utilization of the herbicide glyphosate as a source of phosphorus, nitrogen, or carbon. We added goethite to a humus soil to manipulate the soil's glyphosate sorption capacity. The addition of glyphosate generally either decreased microbial CO2 production or produced no effect. Additions of glyphosate, in combination with glucose and N, did not change the respiration rate in comparison with the same treatment but without glyphosate. In contrast, glyphosate additions combined with glucose and P decreased microbial growth, whereas the combination with goethite counteracted the negative effect. The different treatments were examined using attenuated total reflectance Fourier transform (ATR-FTIR) spectroscopy; the results suggest that glyphosate was de-carboxylated in the sorbed state. Stimulating microbial growth by the addition of glucose and nitrogen resulted in further oxidation of glyphosate and only phosphate was detectable on the goethite surface after 13 days incubation. Our results show that sorbed glyphosate is microbially degradable, and it retards microbial activity. This study emphasizes the importance of combining quantitative measurements with a molecular-level examination, to better understand biogeochemical processes.


Subject(s)
Glycine/analogs & derivatives , Herbicides/metabolism , Humic Substances/microbiology , Iron Compounds/chemistry , Biodegradation, Environmental , Carbon Dioxide/metabolism , Glucose/pharmacology , Glycine/chemistry , Glycine/metabolism , Minerals , Nitrogen/metabolism , Nitrogen/pharmacology , Phosphorus/metabolism , Spectroscopy, Fourier Transform Infrared , Surface Properties , Glyphosate
18.
SEB Exp Biol Ser ; : 251-67, 2005.
Article in English | MEDLINE | ID: mdl-17633039

ABSTRACT

Soil-surface CO2 efflux ('soil respiration') accounts for roughly two-thirds of forest ecosystem respiration, and can be divided into heterotrophic and autotrophic components. Conventionally, the latter is defined as respiration by plant roots. In Boreal forests, however, fine roots of trees are invariably covered by ectomycorrhizal fungi, which by definition are heterotrophs, but like the roots, receive sugars derived from photosynthesis. There is also a significant leaching of labile carbon compounds from the ectomycorrhizal roots. It is, therefore, more meaningful in the context of carbon balance studies to include mycorrhizal fungi and other mycorrhizosphere organisms, dependent on the direct flux of labile carbon from photosynthesis, in the autotrophic component. Hence, heterotrophic activity becomes reserved for the decomposition of more complex organic molecules in litter and other forms of soil organic matter. In reality, the complex situation is perhaps best described as a continuum from strict autotrophy to strict heterotrophy. As a result of this, and associated methodological problems, estimates of the contribution of autotrophic respiration to total soil respiration have been highly variable. Based on recent stand-scale tree girdling experiments we have estimated that autotrophic respiration in boreal forest accounts for up to 50-65% of soil respiration during the snow-free part of the year. Girdling experiments and studies of the delta(13)C of the soil CO2 efflux show that there is a lag of a few days between the carbon uptake by photosynthesis and the release by autotrophic soil respiration of the assimilated carbon. In contrast, estimates of 'bomb 14C' and other approaches have suggested that it takes years to decades between carbon uptake via photosynthesis and the bulk of soil heterotrophic activity. Temperature is normally used as a driver in models of soil processes and it is often assumed that autotrophic soil activity is more sensitive to temperature than is heterotrophic activity, but this is questionable. It is inherently difficult to make a precise separation of autotrophic and heterotrophic respiration from soils. The partitioning between these two components is highly variable in space and time, and taxonomic autotrophs and heterotrophs may perform the function of the other group to some degree. Care should be taken to disturb as little as possible the delicate plant-microbe-soil system, and this speaks for non-intrusive isotopic methods. There are, however, problems in modelling the flux of isotopes through this complex system. Girdling of tree stands is a very robust alternative approach to make the distinction between autotrophic and heterotrophic activities, but ultimately kills the trees and cannot, therefore, always be used. A further development would be to block the phloem sugar transport reversibly. We propose that thus assumption needs further critical testing.


Subject(s)
Autotrophic Processes/physiology , Carbon Dioxide , Climate , Greenhouse Effect , Heterotrophic Processes/physiology , Soil Pollutants , Environmental Monitoring/methods , Photosynthesis , Plant Roots/metabolism , Respiration , Soil Microbiology , Trees/metabolism
19.
Biomaterials ; 25(9): 1723-34, 2004 Apr.
Article in English | MEDLINE | ID: mdl-14697873

ABSTRACT

Animal experimentation is an integrated part of tissue engineering research. This paper investigates what scientists conducting such experimentation should reasonably take into consideration from an ethical point of view. It is argued that scientists should use their moral imagination in making fundamental ethical choices, in reflecting on legal regulation, in taking public opinion seriously, and in balancing human benefit and animal harm as expected outcomes of the experiments.


Subject(s)
Animal Experimentation/ethics , Disease Models, Animal , Ethics, Research , Models, Animal , Risk Assessment/ethics , Tissue Engineering/ethics , Animal Experimentation/legislation & jurisprudence , Animal Experimentation/standards , Animal Welfare/ethics , Animals , Conflict of Interest , Humans , Morals , Public Opinion , Risk Assessment/standards , Social Responsibility , Tissue Engineering/legislation & jurisprudence , Tissue Engineering/standards
20.
Oecologia ; 137(2): 252-7, 2003 Oct.
Article in English | MEDLINE | ID: mdl-12883986

ABSTRACT

A wide range of recent studies have indicated that organic nitrogen may be of great importance to plant nitrogen (N) nutrition. Most of these studies have, however, been conducted in laboratory settings, excluding important factors for actual plant uptake, such as competition, mycorrhizal associations and soil interactions. In order to accurately evaluate the importance of different N compounds to plant N nutrition, field studies are crucial. In this study, we investigated short- as well as long-term plant nitrogen uptake by Deschampsia flexuosa, Picea abies and Vaccinium myrtillus from 15NO3-, 15NH4+ and (U-13C, 15N) arginine, glycine or peptides. Root N uptake was analysed after 6 h and 64 days following injections. Our results show that all three species, irrespective of their type of associated mycorrhiza (arbuscular, ecto- or ericoid, respectively) rapidly acquired similar amounts of N from the entire range of added N sources. After 64 days, P. abies and V. myrtillus had acquired similar amounts of N from all N sources, while for D. flexuosa, the uptake from all N sources except ammonium was significantly lower than that from nitrate. Furthermore, soil analyses indicate that glycine was rapidly decarboxylated after injections, while other organic compounds exhibited slower turnover. In all, these results suggest that a wide range of N compounds may be of importance for the N nutrition of these boreal forest plants, and that the type of mycorrhiza may be of great importance for N scavenging, but less important to the N uptake capacity of plants.


Subject(s)
Mycorrhizae/physiology , Nitrogen/metabolism , Nitrogen/pharmacokinetics , Picea/physiology , Poaceae/physiology , Trees , Vaccinium myrtillus/physiology , Glycine/metabolism , Plant Roots/microbiology , Plant Roots/physiology , Quaternary Ammonium Compounds/analysis , Soil
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