Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Lesões cerebrais agudas e sua influência sobre a motilidade gastrintestinal

A hemorragia subaracnóide é um exemplo de agravo capaz de elevar a pressão intracraniana a patamares de expressiva morbidade. A dilatação gástrica aguda e o retardo do esvaziamento gástrico são alterações de relevância fisiopatológica em pacientes com hipertensão intracraniana, sendo a normalização desses parâmetros útil para otimizar a recuperação dos pacientes vítimas de lesões do sistema nervoso central. Conduziu-se uma revisão bibliográfica em revistas de pesquisa médico-acadêmica e bibliotecas eletrônicas na área das ciências da saúde nacionais e internacionais nos últimos vinte e oito anos a respeito do eixo funcional cérebro-trato gastrintestinal e seu comportamento em animais experimentais ou pacientes com lesão cerebral aguda. A diminuição do tônus parassimpático é uma potencial causa da intolerância alimentar associado a hipertensão intracraniana. O comportamento do esvaziamento gástrico e do trânsito do trato gastrintestinal seguem padrão bifásico: uma fase inicial de esvaziamento gástrico acelerado e uma fase tardia de letargia intestinal. Observações experimentais são importantes para compreender o difícil manejo nutricional e volêmico de pacientes em terapia intensiva que evoluem com HIC secundária a um trauma crânio encefálico ou após hemorragia subaracnóide pós-rotura aneurismática cerebral. A elevação da pressão intracraniana causa incremento na atividade simpática, que é responsável por muitos dos sintomas periféricos sistêmicos e gastrintestinais. Conclui-se que as lesões cerebrais agudas que cursam com elevação importante da pressão intracraniana retardam o esvaziamento gastrintestinal tendo como via fisiopatológica as alterações no sistema nervoso autônomo

THE PARTICIPATION OF THE NITRERGIC PATHWAY IN INCREASED RATE OF TRANSITORY RELAXATION OF LOWER ESOPHAGEAL SPHINCTER INDUCED BY RECTAL DISTENSION IN DOGS

Context The rectal distension in dogs increases the rate of transitory lower esophageal sphincter relaxation considered the main factor causing gastroesophageal reflux. Objectives The aim of this study was evaluate the participation of the nitrergic pathway in the increased transitory lower esophageal sphincter relaxation rate induced by rectal distension in anesthetized dogs. Methods Male mongrel dogs (n = 21), weighing 10-15 kg, were fasted for 12 hours, with water ad libitum. Thereafter, they were anesthetized (ketamine 10 mg.Kg-1 + xylazine 20 mg.Kg-1), so as to carry out the esophageal motility evaluation protocol during 120 min. After a 30-minute basal period, the animals were randomly intravenous treated whith: saline solution 0.15M (1ml.Kg-1), L-NAME (3 mg.Kg-1), L-NAME (3 mg.Kg-1) + L-Arginine (200 mg.Kg-1), glibenclamide (1 mg.Kg-1) or methylene blue (3 mg.Kg-1). Forty-five min after these pre-treatments, the rectum was distended (rectal distension, 5 mL.Kg-1) or not (control) with a latex balloon, with changes in the esophageal motility recorded over 45 min. Data were analyzed using ANOVA followed by Student Newman-Keuls test. Results In comparison to the respective control group, rectal distension induces an increase in transitory lower esophageal sphincter relaxation. Pre-treatment with L-NAME or methylene blue prevents (P<0.05) this phenomenon, which is reversible by L-Arginine plus L-NAME. However, pretreating with glibenclamide failed to abolish this process. Conclusions Therefore, these experiments suggested, that rectal distension increases transitory lower esophageal sphincter relaxation in dogs via through nitrergic pathways

1.8 cineole decreases gastric compliance in anesthetized rats 1.8 cineol diminui a complacência gástrica de ratos anestesiados

PURPOSE: To study the effect of 1,8 cineoleee components of the essencial oil of Croton nepetaefolius - plant of North-East of Brasil, used in the popular medicine for riots of the gastrointestinal tract - on the motor behavior of the gut of Wistar rats. METHODS: Used 16 male animals under jejun of 24h weighing 300-350g. The effect of 1.8 cineoleee (1 or 3mg/Kg) on gastric compliance had been lead in anaesthetized rats. The variations of the gastric volume (GV), had been measured by plethysmography, while AP, HR and CVP had been monitored continuously by a digital system of data acquisition. RESULTS: Observe reduction of the GV, which was significant on 30, 40, 50 and 60min after treatment (2.0&plusmn;0.1; 1.9&plusmn;0.1; 1.8&plusmn;0.1 and 1.7&plusmn;0.1mL, versus 2.1&plusmn;0.2mL). The AP presented significant fall after the administration of 1.8 cineoleee, remaining thus during 60min of monitorization (87.9&plusmn;7.7; 87.6&plusmn;7.1; 87.9&plusmn;6.4; 87.8&plusmn;5.7; 86.0&plusmn;5.5 and 87.7&plusmn;6.0mmHg, respectively versus 94.4&plusmn;6.2 mmHg), as well as the HR (366.3&plusmn;13.4; 361.7&plusmn;11.5; 357.3&plusmn;10.4; 353.0&plusmn;10.4; 348.3&plusmn;11.1 and 350.4&plusmn;13.7bpm, respectively versus 395.2&plusmn;11.1bpm). The CVP did not suffer significant variations after treatment. CONCLUSION: Observe the 1.8 cineoleee reduces the gastric compliance in anaesthetized rats besides presenting effect hipotensor and bradicardic; probably for direct action on the gastrointestinal and vascular smooth muscel and moduling the autonomic nervous system.<br>OBJETIVO: Estudar o efeito do 1.8 cineol, componente do Cróton nepetaefolius (planta do Nordeste) comumente usada na medicina popular para distúrbios do trato gastrintestinal (TGI), sobre o comportamento motor do TGI de ratos Wistar anestesiados. MÉTODOS: Utilizamos 16 animais machos, pesando entre 300 a 350g. Os estudos de complacência gástrica foram conduzidos em animais sob jejum de 24h. As variações do volume gástrico (VG), foram medidas por pletismografia, enquanto a PA, FC e PVC foram monitoradas continuamente por um sistema digital de aquisição de dados. RESULTADOS: Observamos diminuição do VG, o qual foi significativo aos 30, 40, 50 e 60min após o tratamento com 1.8 cineol quando comparado ao perído basal (2,0&plusmn;0,1; 1,9&plusmn;0,1; 1,8&plusmn;0,1 e 1,7&plusmn;0,1mL, vs 2,1&plusmn;0,2mL). A PA apresentou queda significativa após a administração de 1.8 cineol, mantendo-se assim durante os 60min de monitoração (87,9&plusmn;7,7; 87,6&plusmn;7,1; 87,9&plusmn;6,4; 87,8&plusmn;5,7; 86,0&plusmn;5,5 e 87,7&plusmn;6,0mmHg, respectivamente vs 94,4&plusmn;6,2; mmHg), bem como a FC (366,3&plusmn;13,4; 361,7&plusmn;11,5; 357,3&plusmn;10,4; 353,0&plusmn;10,4; 348,3&plusmn;11,1 e 350,4&plusmn;13,7bpm respectivamente vs 395,2&plusmn;11,1bpm). Já a PVC não sofreu variações significativas durante após o tratamento. CONCLUSÃO: O 1.8 cineol diminui a complacência gástrica em ratos anestesiados além de apresentar efeitos hipotensor e bradicárdico; provavelmente por ação direta sobre a musculatura lisa gastrintestinal e vascular e modulação do sistema nervoso autônomo

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