Causas, consequências e métodos atribuídos para prevenir a desertificação na caatinga / Causes, consequences and methods attributed to prevent desertification in caatinga

A desertificação é um fenômeno que resulta da combinação de fatores naturais, principalmente as episódicas secas; e de fatores antrópicos, como sobrepastoreio, desmatamento e remoção da cobertura vegetal, juntamente com as atividades agrícolas que ocorrem acima da capacidade de suporte do ambiente. No Brasil o bioma Caatinga é o mais atingido, perdendo apenas para a Floresta Atlântica e o Cerrado. Estima-se que 80% da vegetação encontre-se completamente modificada, devido ao extrativismo e a agropecuária, apresentando-se a maioria dessas áreas em estádios iniciais ou intermediários de sucessão ecológica. Entretanto, o objetivo da presente pesquisa bibliográfica foi mostrar as causas e as consequências da desertificação da Caatinga e os métodos que são atribuídos para prevenção. É preciso ressaltar que as restrições físicas e químicas dos solos, a escassez de água no Semiárido nordestino, bem como a exploração intensiva dos recursos naturais e o super pastoreio tornam a Caatinga vulnerável à desertificação e à ameaça de extinção de espécies da fauna e da flora nativa da região, entretanto, esse processo pode ser controlado, evitado, e até mesmo revertido, desde que haja o envolvimento da população e que os órgãos governamentais proponham soluções, junto com as comunidades e as escolas e toda a sociedade para resolver, ou ao menos, buscar alternativas sustentáveis, oferecendo auxílio técnico para o manejo dessas áreas e incentivando a preservação ambiental de maneira que não ocorra uma sobrecarga de problemas nas áreas de risco. Nos locais onde o processo de desertificação já se instalou são necessários investimentos para sua contenção; porém, o custo é da ordem de bilhões de dólares

Corrigendum: Graves’ Disease

DG presents with three main presentations: hyperthyroidism with diffuse goiter, infiltrative ophthalmopathy and pre-tibial myxedema. Patients with Graves’ disease can rarely develop severe hyperthyroidism. The hyperthyroidism of Graves’ disease is characterized immunologically by the lymphocytic infiltration of the thyroid gland and by the activation of the immune system with elevation of the circulating T lymphocytes. In GD, goiter is characteristically diffuse. May have asymmetric or lobular character, with variable volume. The clinical manifestations of hyperthyroidism are due to the stimulatory effect of thyroid hormones on metabolism and tissues. Nervousness, eye complaints, insomnia, weight loss, tachycardia, palpitations, heat intolerance, damp and hot skin with excessive sweating, tremors, hyperdefecation and muscle weakness are the main characteristics. In the laboratory diagnosis, biochemical and hormonal exams will be done to assess thyroid hormones and the antithyroid antibodies. Additionally, imaging tests may be performed, such as radioactive iodine capture in 24 hours, ultrasonography, thyroid scintigraphy and fine needle aspiration. It is necessary to make the differential diagnosis of Graves’ disease for thyrotoxicosis, subacute lymphocytic thyroiditis and toxic nodular goiter. The treatment of DG aims to stop the production of thyroid hormones and inhibit the effect of thyroid hormones on the body. Hyperthyroidism caused by DG can be treated in the following ways: it may be the use of synthetic antithyroid medicines, thionamides, MMI being a long-term medicine, it allows a single daily dose, and adherence to treatment occurs, a disadvantage is that it cannot be used in pregnant women; beta-blockers, preferably used in the initial phase of DG with thionamides; radioactive iodine therapy (RAI), being the best cost–benefit and preventing DG recurrence; finally the total thyroidectomy, causing the withdrawal of the thyroid gland. Therefore, it should be discussed with the patient what is the best treatment for your case, with a view to the post and against each approach. If the patient develops Graves ophthalmopathy, in lighter cases the artificial tears should be used, and in more severe cases can be used as treatment, corticosteroids, orbital decompression surgery, prisms and orbital radiotherapy. In addition, the patient should keep their body healthy, doing exercise and healthy eating, following the guidance of their doctor

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved