Determination of the distribution coefficient (log Kd) of oxytetracycline,tylosin A,olaquindox and metronidazole in manure

Olaquindox (log Kow = -2.3) and metronidazole (log Kow = -0.1) both have low tendencies to sorp to particles in manure. This corresponds with the negative log Kow values of these antibiotics. Tylosin (log Kow = 1.63) and oxytetracycline (log Kow = -1.12) sorp relatively strongly to the manure particles and have log Kd values between 1.5 and 2.0. The tendency to bind to manure was ranked after increasing binding as follows: metronidazole < olaquindox < tylosin A and oxytetracycline. This order of ranking is consistent with results of sorption in soil. Our experiments illustrate that for some antibacterial agents estimation of the partitioning coefficients, Kd, cannot be made from Kow and f(oc) alone. Sorption of oxytetracycline to manure is much higher than expected from the negative log Kow value of the compound. It is believed that sorption of oxytetracycline to manure is influenced by ionic binding to divalent metal ions as such Mg2+ and Ca2+ as well as other charged compounds in the matrix. Binding of oxytetracycline to soil is stronger than the binding to manure. This is most likely due to the strong mineral related metal complexes formed between soil, metal ion and oxytetracycline. These complexes are not known to exist in manure. The relatively strong sorption of tylosin A to manure corresponds with data found for soil sorption of tylosin. Tylosin has a log Kow value of 2.5, thus it is not surprising that this drug binds strongly to manure.     

Nature and Nature Values in Organic Agriculture. An Analysis of Contested Concepts and Values Among Different Actors in Organic Farming

The relationship between agriculture and nature is a central issue in the current agricultural debate. Organic Farming has ambitions and a special potential in relation to nature. Consideration for nature is part of the guiding principals of organic farming and many organic farmers are committed to protecting natural qualities. However, the issue of nature, landscape, and land use is not straightforward. Nature is an ambiguous concept that involves multiple interests and actors reaching far beyond farmers. The Danish research project Nature Quality in Organic Farming has investigated the relationship between nature and organic farming. This article will focus on an expert workshop held in connection with the project that investigates the way different actors conceptualize nature. Farmers, scientists, and non-governmental organizations came together to discuss their experiences of nature and expectations of organic agriculture. From this interaction, it was clear that nature is a contested notion. Different understandings of nature exist within the three groups and there is disagreement as to whether emphasis should be given to biological qualities, production values, or experiential and aesthetic perspectives. This complexity provides a challenge to organic farming as well as to the implementation of nature considerations in general. It illustrates an underlying battle for the right to define nature and nature quality and essentially decide what organic farmers should work towards. We argue that successful implementation requires organic farmers to carefully consider what expectations they wish to meet. Optimally it is dependent on a dialog between stakeholder interest groups that allows for multivocality and pluralism.     

The Idea of “Ethical Accounting” for a Livestock Farm

This paper presents the idea of a decision-support system for a livestock farm, called “ethical accounting”, to be used as an extension of traditional cost accounting. “Ethical accounting” seeks to make available to the farmer information about how his decisions affect the interests of farm animals, consumers and future generations. Furthermore, “ethical accounting” involves value-based planning. Thus, the farmer should base his choice of production plan on reflections as to his fundamental objectives, and he should make his final decision only after having seriously considered the various consequences for the affected parties. This revised version was published online in August 2006 with corrections to the Cover Date.     

The adequacy of GWPs as indicators of damage costsincurred by global warming

This article looks at the ability of Global Warming Potentials (GWPs) towork as indicators of equivalence for temperature development and damagecosts. We look at two abatement scenarios that are equivalent when using100-year GWPs: one scenario reduces short-lived gases, mainly methane(CH₄); the other scenario reduces carbon dioxide (CO₂).Despite their equivalence in terms of CO₂ equivalents, the scenariosdo not result in equal rates or levels of temperature change. The disparitiescontinue as we move further down the chain of causality toward damagecosts, measured either in terms of rate of climate change or level of climatechange. Compared to the CH₄ mitigation scenario, the CO₂mitigation scenario gives present value costs 1.3 and 1.5 times higher forlevel- and rate-dependent damage costs, respectively, assuming a discountrate of 3%. We also test the GWPs for other time horizons and theconclusions remain the same; using GWP as an index to reflect equivalentclimate effects and damage costs from emissions is questionable.     

Fragile X demonstrated retrospectively in amniotic cells cultured in low folate medium

Chromosome analysis in a boy aged 10 months, with psychomotor retardation, revealed the fragile X-chromosome in lymphocytes and skin fibroblasts cultured in low folate medium (TC 199). Amniocentesis and chromosomal analysis had been carried out during pregnancy because of advanced maternal age. Review of the slides from amniotic fluid cells grown routinely in low folate medium showed the marker X in 10.6 per cent of the metaphases. Possible explanations for the appearance of the marker X in amniotic cell culture are discussed.     

Early prenatal direct gene diagnosis of cystic fibrosis in a twin pregnancy and subsequent selective termination

We present a case of prenatal diagnosis of cystic fibrosis (CF) in one twin at 11–12 weeks of gestation. The parents had previously had two children, one of whom is alive and healthy and one who died of CF at the age of 2½ months. The parents were both known to be carriers of the ΔF508 mutation. Chorionic villus sampling (CVS) was performed and direct gene analysis showed that one fetus was homozygous for the ΔF508 mutation, while the other fetus did not have the mutation at all. Both fetuses had normal karyotypes. Selective termination was subsequently performed. The pregnancy continued without complications except for mild pre-eclampsia at term. The woman had a Caesarean section. The genetic diagnosis was confirmed after birth.     

Amniotic fluid acetylcholinesterase in the prenatal diagnosis of open neural tube defects and abdominal wall defects: A comparison of gel electrophoresis and a monoclonal antibody immunoassay

Stored amniotic fluid samples collected in Oxford and East Birmingham as part of the Collaborative Acetylcholinesterase Study were assayed for the presence of acetylcholinesterase (AChE) using a monoclonal antibody (4F19) enzyme antigen immunoassay. These results were compared with the results of a gel AChE which had been performed earlier. A total of 5689 samples from singleton pregnancies were analysed (including 36 with anencephaly, 77 with open spina bifida and 17 with anterior abdominal wall defects). The gel test yielded detection rates of 97% for anencephaly, 99% for open spina bifida and 94% for abdominal wall defects; the false positive rate (excluding pregnancies associated with serious abnormalities, miscarriages and intrauterine deaths) was 0·24%. The monoclonal test yielded similar results; using appropriate cut-off values to allow for differences in acetylcholinesterase levels in blood stained and clear samples, a similar false-positive rate of 0·22% was associated with detection rates of 97%, 95 % and 71 % respectively for the three types of defect. Although the detection rates and the false positive rate were slightly higher for the gel test, a result that might be explained by a decrease in AChE activity caused by storage of the samples, the monoclonal test has the advantages of requiring less interpretative expertise, it can be performed on a larger number of samples a day and it is not affected by contamination with fetal calf serum.     

Growth conditions affect carotenoid-based plumage coloration of great tit nestlings

 Carotenoid-based integument colour in animals has been hypothesised to signal individual phenotypic quality because it reliably reflects either foraging efficiency or health status. We investigated whether carotenoid-derived yellow plumage coloration of fledgling great tits (Parus major) reflects their nestling history. Great tit fledglings reared in a poor year (1998) or in the urban habitat were less yellow than these reared in a good year (1999) or in the forest. The origin of nestlings also affected their coloration since nestlings from a city population did not improve their coloration when transferred to the forest. Brood size manipulation affected fledgling colour, but only in the rural population, where nestlings from reduced broods developed more yellow coloration than nestlings from increased and control broods. Effect of brood size manipulation on fledgling plumage colour was independent of the body mass, indicating that growth environment affects fledgling body mass and plumage colour by different pathways. Received: 20 March 2000 / Accepted in revised form: 4 September 2000