Emissões de queimadas em ecossistemas da América do Sul / Emissões de queimadas em ecossistemas da América do Sul

As queimadas que ocorrem majoritariamente em áreas tropicais do planeta, são fontes importantes de poluentes para a atmosfera. Na América do Sul, durante os meses de inverno, uma área, principalmente de ecossistemas de cerrado e floresta, da ordem de 40 mil km² é queimada anualmente. Estas queimadas ocorrem primariamente nas regiões Amazônica e do Brasil Central, porém, através do transporte atmosférico de suas emissões resulta uma distribuição espacial de fumaça sobre uma extensa área, ao redor de 4-5 milhões de km², em muito superior a área onde estão concentradas as queimadas. Durante a combustão de biomassa são emitidos para a atmosfera gases poluentes e partículas de aerossol que interagem eficientemente com a radiação solar e afetam os processos de microfísica e dinâmica de formação de nuvens e a qualidade do ar. Os efeitos destas emissões excedem, portanto, a escala local e afetam regionalmente a composição e propriedades físicas e químicas da atmosfera na América do Sul e áreas oceânicas vizinhas, com potencial impacto em escala global.

Biodiversity meets the atmosphere: a global view of forest canopies.

The forest canopy is the functional interface between 90% of Earth's terrestrial biomass and the atmosphere. Multidisciplinary research in the canopy has expanded concepts of global species richness, physiological processes, and the provision of ecosystem services. Trees respond in a species-specific manner to elevated carbon dioxide levels, while climate change threatens plant-animal interactions in the canopy and will likely alter the production of biogenic aerosols that affect cloud formation and atmospheric chemistry.

Dyschromatopsia in heroin addicts.

The Farnsworth-Munsell 100-hue test was employed to determine whether there was any defect of colour vision in 29 confirmed male heroin addicts who had been successfully detoxified. Forty age-matched males served as controls. A typical normal error score on the FM test is about 40 and an error score of over 100 indicates poor colour discrimination; 86.2% of the eyes of the control group had an error score below 100 while only 17.2% of the eyes of heroin addicts had an error score below 100. The colour confusion among the heroin addicts was in the blue-purple (475-495 mu) range. These results indicate that colour vision defects are more common in heroin addicts.

An evaluation of the undergraduate teaching programme in ophthalmology in Sri Lanka and Malaysia.

The knowledge and clinical and minor surgical skills acquired by 257 medical students in three universities in Sri Lanka and Malaysia were assessed by a questionnaire after they had completed their training period in ophthalmology. This study showed that many medical students graduating from these universities lacked the basic clinical and minor surgical skills essential for a doctor practising in a community in south-east Asia. The responses also indicated that teaching by consultants in all three universities was inadequate and due to these inadequacies the students requested that the duration of their training period be doubled. Ophthalmology is an important component of clinical practice and proper education in this subject is important. An urgent revision of the aims and objectives of the curriculum in ophthalmology is essential to place greater emphasis on this important and much neglected subject, for which very little curricular time is allotted.

Electrolyte imbalances in the aqueous humour in retinoblastoma.

The sodium and potassium concentrations and the lactic dehydrogenase (LDH) activity were estimated in the aqueous and serum of five children with retinoblastoma. Two patients who had a high aqueous LDH activity also showed grossly elevated potassium levels in their aqueous. Though the exact reason for this high potassium concentration in the aqueous is not apparent, it seems likely that cell necrosis within the tumour mass was a contributory factor. It is unlikely that aqueous electrolyte estimations in retinoblastoma could prove to be of any diagnostic value.

Minilaparotomy under acupuncture analgesia.

Minilaparotomy was performed using acupuncture analgesia on 78 female patients seeking voluntary sterilization to determine whether this could be used as a substitute for standard analgesic sedation. In 48 women (62%) no intravenous drug medication was required, and sterilization was successfully performed using only the local anaesthetic and acupuncture electrostimulation. These patients could be discharged within one hour of operation. For a developing country with a shortage of trained anaesthetists, acupuncture analgesia could prove to be a simple, safe and economical method, especially in a rural setting.

The long-term effects of vasectomy on sexual behaviour.

Two hundred soldiers of the Sri Lanka Army who had undergone vasectomy at least 4 years earlier were interviewed by a pretested questionnaire to determine the incidence and nature of any changes in sexual behaviour after the operation. Fifty-six percent reported some change in their sexual behaviour after vasectomy. A decreased frequency of intercourse being reported by 15%, a decreased sexual desire by 19% and changes in sexual behaviour during intercourse by 33%. Seven percent reported that their wives had noticed an alteration in sexual behaviour after operation. In spite of these changes in sexual behaviour after vasectomy the majority of men (92%) reported satisfaction with the operation, which is an indication that changes in sexual behaviour cannot be attributed directly to vasectomy.

PIP: 200 soldiers of the Sri Lanka army who had undergone vasectomy at least 4 years earlier were interviewed by a pretested questionnaire to determine the incidence and nature of any changes in sexual behavior following the operation. 56% reported some change in their sexual behavior after vasectomy. A decreased frequency of intercourse was reported by 15%, a decreased sexual desire by 19%, and changes in sexual behavior during intercourse by 33%. 7% reported that their wives had noticed an alteration in sexual behavior after the operation. In spite of these changes in sexual behavior after vasectomy, the majority of men (92%) reported satisfaction with the operation, which is an indication that changes in sexual behavior cannot be attributed directly to vasectomy.

The effects of vasectomy on testicular volume.

PIP: Testicular volumes of 15 subjects who had at least 2 living children were estimated by caliper measurements before and after vasectomy to determine whether any change in testicular volume occurs following vasectomy. The testicular volumes were calculated using the formula of Macomber and Sanders. The sizes of the testicles ranged from 3.1 ml in a patient who had had mumps at 5 years to 28.6 ml. The mean preoperative testicular volume was 17.9 +or- 4.9 ml. Comparison of the testicular volumes by the t-test before operation and at 5 days, 1 month, 6 months and 1 year postoperation showed no difference at the .05 level of significance.^ieng

Cryocauterization of the vas deferens.

PIP: Cryocauterization of the vas deferens was carried out on 10 acceptors of voluntary sterilization who had at least 2 living children each to determine whether the method could be successfully employed as an alternative to vasoligation and resection. Written consent was obtained from each acceptor and his wife. The initial steps were the same as for routine vasectomy. An isolated segment of the vas deferens 2-3 cm long was cauterized using a 2.5 mm cryoprobe with nitrous oxide as the cryogen. 2 freeze-thaw cycles of 2 minutes each were applied to each point on the vas and the temperature attained was -70 degrees centigrade. The vas was not resected or ligated. Acceptors were advised to use condoms. Sperm counts 3 months postoperative showed live and motile sperm (50,000/ml) in 2 of the specimens; the remainder were azoospermic. Cryocauterization of the vas took longer than a normal vasectomy but caused no pain, discomfort, or bleeding and required no sutures. Because of the high failure rate cryocauterization cannot be recommended as a routine procedure.^ieng

Effect on the intraocular pressure of hypotensive anaesthesia with intravenous trimetaphan.

The intraocular pressure was measured at 5-minute intervals with a Perkins applanation tonometer in 5 patients undergoing routine dacryocystorhinostomy under low-tension anaesthesia with a continuous intravenous infusion of trimetaphan (Arfonad), the systolic pressure being maintained at 66 mmHg. Twelve patients undergoing cataract surgery under the same premedication and anaesthesia but in whom the systemic blood pressure was maintained at normal levels served as controls. A sudden and dramatic lowering of the intraocular pressure to very low levels was noted when the systolic blood pressure was reduced to 60 mmHg. It seems likely that a collapse of the choroidal circulation rather than a decreased aqueous formation due to low perfusion pressure is the most likely cause of the sudden lowering of intraocular pressure.

Effects of acupuncture in bronchial asthma: preliminary communication.

Twenty patients randomly assigned to an experimental and a control group participated in a double blind study to assess the effectiveness of acupuncture in bronchial asthma, using the peak expiratory flow rate (PEFR) as an index of bronchial patency. All patients in the control group showed a significant improvement in their PEFR while only 3 patients in the treated group showed an improvement. A subjective improvement and a reduction in drug dosages were observed in both groups. It is concluded that acupuncture has a placebo effect in bronchial asthma.

[Carpal tunnel syndrome: electroneuromyographic study of 135 cases]. / Síndrome do canal carpeano: estudo eletroneuromiográfico de 135 casos.

One hundred thirty five patients with carpal tunnel syndrome were studied trough electrophysiological techniques. Nerve sensory conductions, motor conductions and electromyography were performed in all patients and the results discussed. The authors call the attention for the technic of sensory conduction stimulating palma and picking up the potentials on the wrist as the most sensitive technic for the early detection of carpal tunnel syndrome.

Sindrome do canal carpeano: estudo eletroneuromiografico de 135 casos. / Carpal tunnel syndrome: electroneuromyographic study of 135 cases

Foram estudadas as alteracoes eletrofisiologicas em 135 pacientes com sindrome do canal carpeano, num total de 270 maos. As medidas das velocidades de conducao sensitiva foram as alteracoes mais frequentes, seguidas das alteracoes de conducao motora e eletromiograficas. A tecnica da medida de conducao sensitiva estimulando a palma da mao e captando o potencial evocado acima do punho mostrou ser a mais sensivel para o diagnostico precoce da SCC

Effects of tenotomy on the motor end plates of fast and slow twitch muscles of the rabbit.

The projection areas of vitally stained motor end plates in normal and tenotomized fast and slow twitch muscles of the rabbit hind limb were measured. There was a significant reduction in the mean projection area of the motor end plates of the slow muscle after tenotomy. There was no significant change in the projection area of the FDL or gastrocnemius motor end plates after tenotomy. After tenotomy the deep (slow) component of the tibialis anterior showed an increase in the mean projection area of its end plates and so approached the faster superficial component in this respect. It appears therefore, that the altered pattern of activity of the slow motoneurons (which is known to occur after tenotomy) is associated with a change in the end plate size towards that normally found in muscles innervated by phasic motoneurons.

Prognostic significance of aqueous humour lactic dehydrogenase activity.

The lactic dehydrogenase (LDH) activity of the aqueous humour has been estimated in both eyes of 7 patients having uniocular retinoblastoma. In 1 patient the aqueous humour LDH activity in the healthy eye was above normal, but there was no clinical evidence of malignancy. Tumour tissue was detected in this eye 9 months later, and the aqueous humour showed a rise in LDH activity. A high LDH activity persisted even after irradiation, though no tumour tissue was visible ophthalmoscopically. It is suggested that the estimation of the LDH activity in the aqueous humour of the healthy eye in cases of uniocular retinoblastoma might be of value in the early detection of a bilateral retinoblastoma.

Correlation of aqueous humour lactic acid dehydrogenase activity with intraocular pathology.

An analysis of the lactic acid dehydrogenase (LDH) activity in the aqueous humour of 24 enucleated eyes with retinoblastoma showed that though there was no relationship between the LDH levels and the age of the patient, there appeared to be an increase in the LDH activity with increase in the duration of the tumour. Undifferentiated tumour cells and tumour cell necrosis seemed to contribute to an increase of LDH levels in the aqueous humour, but there was no relationship between the occurrence of calcification and the LDH secretion into the aqueous humour. Massive cell necrosis caused by radiotherapy and central retinal artery occlusion significantly increased the LDH levels in the aqueous. It also appeared that recurrence was common after external cobalt therapy and that secondary extension of the tumour into the optic nerve and choroid was favoured by this procedure.

Postinflammatory and malignant protein patterns in aqueous humour.

Normal aqueous humour and the aqueous humour of patients with cataract is virtually protein-free. Patients having retinoblastoma and non-malignant postinflammatory lesions show significantly high quantities of proteins in the aqueous humour. Retinoblastoma is associated with an increase in the globulin content and an albumin/globulin ratio below unity, while non-malignant postinflammatory intraocular conditions show a rise of the albumin fraction with an albumin/globulin ratio above unity. It seems likely that the leakage of protein into the aqueous is different in the two conditions, and a transcellular route is postulated as being the cause in malignant conditions. The estimation of protein patterns in the aqueous humour may be of value in the diagnosis of intraocular malignancy.

4-hydroxy-3-methoxymandelic acid (HMMA) excretion in retinoblastoma.

4-Hydroxy-3-methoxymandelic acid (HMMA) concentrations in aqueous humour, urine, and serum were simultaneously estimated to determine if these levels were raised in cases of retinoblastoma. The catecholamine content of aqueous humour was significantly higher than that of urine and serum, but as there was no significant difference in the HMMA concentration in retinoblastoma and other non-malignant conditions it seems likely that retinoblastoma is not a catecholamine-secreting tumour.