Indications for Intravenous T3 and T4.

Therapy with thyroid hormones normally is restricted to substitution therapy of patients with primary or secondary hypothyroidism. Typically, thyroid hormones are given orally. There are few indications for intravenous use of thyroid hormones. Indications for parenteral application are insufficient resorption of oral medications due to alterations of the gastrointestinal tract, partial or total loss of consciousness, sedation in the intensive care unit or shock. In almost all cases, levothyroxine is the therapy of choice including congenital hypothyroidism. In preterm infants with an altered thyroid hormone status, studies with thyroid hormones including intravenous liothyronine showed a normalisation of T3 levels and in some cases an amelioration of parameters of ventilation. A benefit for mortality or later morbidity could not be seen. Effects on neurological improvements later in life are under discussion. Decreased thyroid hormone levels are often found after cardiac surgery in infants and adults. Intravenous therapy with thyroid hormones improves the cardiac index, but in all other parameters investigated, no substantial effect on morbidity and mortality could be demonstrated. Oral liothyronine therapy in these situations was equivalent to an intravenous route of application. In myxoedema coma, intravenous levothyroxine is given for 3 to 10 days until the patient can take oral medication and normal resorption in the gastrointestinal tract is achieved by restoring at least peripheral euthyroidism. Intravenous levothyroxine is the standard in treating patients with myxoedema coma. A protective effect on the heart of i.v. levothyroxine in brain-dead organ donors may be possible.

A framework for developing completion criteria for mine closure and rehabilitation.

The mining industry is a major contributor to Australia's economy. However, such returns may come at high environmental and social costs, including loss of biodiversity or heritage values. Thus, companies worldwide are required to rehabilitate mine sites to a state that is safe, non-polluting and capable of supporting an agreed post-mining land use. While national and international guidelines on mine rehabilitation and closure exist, there is a lack of guidance on how to define achievable and measurable criteria that reflect rehabilitation success. This often leads to discrepancies between proponents and regulators, which hinder progression towards mine closure and relinquishment. The purpose of this study was to develop a systematic framework for the definition of completion criteria for mine closure and rehabilitation. The study was informed by a global review of the literature and collaborative research with mining stakeholders from Western Australia. The proposed framework consists of six fundamental steps: 1) selection of post mining land use; 2) definition of aspects and closure objectives; 3) selection of reference(s); 4) selection of attributes; 5) definition of completion criteria; and 6) evaluation of performance. This framework is the first to provide a step-by-step guide for defining site-specific completion criteria and applying a risk-based monitoring approach throughout the life of mine. The framework is applicable across jurisdictions and industries, in Australia and internationally, that require similar rehabilitation of disturbed lands.

Tolerance and induction of tolerance to Ni of arbuscular mycorrhizal fungi from New Caledonian ultramafic soils.

The influence of Ni on arbuscular mycorrhizal fungi (AMF) has not been studied yet. We tested the tolerance to Ni of five AMF isolates from New Caledonian ultramafic soils. Spore germination indicated that these isolates were clearly more tolerant to Ni than three other isolates from non-ultramafic soils. They were able to germinate at 30 microg g(-1) Ni, whereas spores of the non-ultramafic isolates were totally inhibited at 15 microg g(-1) Ni. Among the ultramafic isolates, two were obtained from roots of Ni-hyperaccumulating plants. Their tolerance to Ni was clearly higher than all the other isolates. The proportion of germinated spores of the different isolates in contact with ultramafic soils showed the same tendencies as those observed with Ni solutions. Tolerance to Ni increased when spores were produced from mycorrhiza on plants grown on sand containing 20 microg g(-1) Ni, in comparison with those produced on sand without Ni. These results indicate that the tolerance to Ni of AMF spores can be induced by the presence of this metal in the substrate.