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

Effects of nitrosyl ruthenium in injury brain induced by ischemia and reperfusion of rats

IntroduÃÃo e objetivo: Doadores de NO podem diminuir a lesÃo neuronal durante a isquemia e reperfusÃo cerebral (I/R) por aumento do fluxo sanguÃneo cerebral. O objetivo deste estudo à avaliar se um novo complexo de nitrosilo complexo de rutÃnio (Rut-bpy) capaz liberar NO direto na musculatura lisa vascular apresenta algum efeito durante I/R. MÃtodo: Foram utilizados 96 ratos machos, da linhagem Wistar, com peso mÃdio de 290.27 g, distribuÃdos em 2 fases com 8 grupos cada: Fase de isquemia 4 grupos sham (SF, Rut-bpy,L-NAME e L-NAME+Rut-bpy) e 4 grupos isquemia (SF, Rut-bpy,L-NAME e L-NAME+Rut-bpy); da mesma forma foi dividido a fase de reperfusÃo ( 4 grupos sham e 4 grupos isquemia/reperfusÃo) com as mesmas drogas teste da fase de isquemia. Foi utilizado um modelo de isquemia cerebral global incompleta, com oclusÃo da artÃria carÃtida comum bilateral e administraÃÃo do SF, Rut-bpy e L-NAME via intraperitoneal. No final do experimento os animais foram decapitados e o cÃrebro fatiado para ser avaliado à Ãrea de lesÃo por histoquÃmica. Durante todo o experimento a PAM dos animais foi monitorizada. Resultados: DiminuiÃÃo da relaÃÃo Ãrea de lesÃo/Ãrea de tecido cerebral tanto na fase de isquemia (0.526 + 0.012 com SF vs 0.216 + 0.07 com Rut-bpy,; p<0.05) como na fase de reperfusÃo (0.4201 + 0.04 com SF vs 0.114 + 0.03 com Rut-bpy; p<0.05). A variaÃÃo da PAM foi menor nos animais tratados com Rut-bpy (20.89 + 11.77 com SF vs 6.49 + 4.65 com Rut-bpy) ao final da isquemia e inicio da reperfusÃo. ConclusÃo: O Rut-bpy tem efeito protetor neuronal durante evento de I/R e que o mesmo consegue manter a PAM mais estÃvel durante o inicio da reperfusÃo.Background and purpose - Nitric oxide (NO) donors are known to reduce neuronal damage during brain ischemia and reperfusion by increasing the blood flow. Rut-bpy is a novel nitrosyl-ruthenium complex releasing NO directly into the vascular smooth musculature. The objective of the study was to evaluate the effect of Rut-bpy on a rat model of brain ischemia and reperfusion. Methods - Ninety-six male Wistar rats weighing approximately 290g were randomly assigned to 16 groups. Four groups and their respective sham groups were submitted to ischemia (Stage 1), while four groups and their respective sham groups were submitted to ischemia + reperfusion (Stage 2). At each stage of the experiment the groups were treated pairwise with saline solution (SS), Rut-bpy, L-NAME and L-NAME+Rut-bpy, respectively. The study was based on an incomplete global brain ischemia model with occlusion of the common bilateral carotid arteries and intraperitoneal administration of the study drugs. Following the experiment the animals were decapitated and the brain was sectioned for histochemical evaluation of the area of damage. The mean arterial blood pressure (MABP) was monitored throughout the experiment. Results - In the groups receiving Rut-bpy the damaged area/total area ratio decreased significantly during both ischemia (SS: 0.526  0.012 vs. Rut-bpy: 0.216  0.07; p<0.05) and reperfusion (SS: 0.4201  0.04 vs. Rut-bpy: 0.114  0.03; p<0.05). MABP oscillated significantly less during the transition from ischemia to reperfusion in the groups treated with Rut-bpy (SS: 20.89 mmHg  11.77 vs. Rut-bpy: 6.49 mmHg  4.65; p<0.05). Conclusion - Rut-bpy was shown to protect rat brain cells during ischemia and reperfusion and helped maintain the blood pressure relatively stable during the transition from ischemia to reperfusion

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

Effects of Rut-bpy (Cis-[Ru(bpy)2(SO3)(NO)]PF 6), a novel nitric oxide donor, in L-NAME-induced hypertension in rats Efeitos do Rut-bpy (Cis-[Ru(bpy)2(SO3)(NO)]PF 6), um novo doador de óxido nítrico, na hipertensão induzida com L-NAME em ratos

PURPOSE: To evaluate the effect of Rut-bpy (Cis-[Ru(bpy)2(SO3)(NO)]PF 6), a novel nitric oxide donor in N&#969;-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats. METHODS: Twenty-four male Wistar rats were randomly assigned to four groups (n=6), named according to the treatment applied (G1-Saline, G2-Rut-bpy, G3-L-NAME and G4-L-NAME+Rut-bpy). L-NAME (30 mg/Kg) was injected intraperitoneally 30 minutes before the administration of Rut-bpy (100 mg/Kg). Mean abdominal aorta arterial blood pressure (MAP) was continuously monitored. RESULTS: Mean arterial blood pressure (MAP) in G3 rats rose progressively, reaching 147±16 mmHg compared with 100±19 mm Hg in G1 rats (p<0.05). In G4 rats, treated with L-NAME+Rut-bpy, MAP reached 149+11 mm Hg while in G2 rats, treated with Rut-bpy, MAP values were 106±11 mm Hg. In G1 rats these values decreased progressively reaching 87+14 mm Hg after 30 minutes. An important finding was the maintenance of the MAP throughout the experiment in G2 rats. CONCLUSION: Rut-bpy does not decrease the MAP in L-Name induced hypertensive rats. However, when it is used in anesthetized hypotensive rats a stable blood pressure is obtained.<br>OBJETIVO: Avaliar o efeitos do Rut-bpy (Cis-[Ru (bpy)2(SO3)(NO)] PF6), um novo doador de óxido nítrico, em ratos hipertensos induzidos pelo éster metílico de N-nitro-L-arginina (L-NAME). MÉTODOS: Vinte e quatro ratos Wistar machos foram distribuídos aleatoriamente em quatro grupos (n = 6), nomeados de acordo com o tratamento aplicado (G1-Salina, G2-Rut-bpy, G3-L-NAME e G4-L-NAME+Rut -bpy). L-NAME (30 mg / Kg) foi injetado por via intraperitoneal 30 minutos antes da administração de Rut-bpy (100 mg / kg). A pressão arterial média (PAM) da aorta abdominal foi monitorada continuamente. RESULTADOS: A pressão arterial média (PAM) em ratos do grupo G3 subiu progressivamente, chegando a 147 ±16 mm Hg, em comparação com 100 ±19 mm Hg em ratos do G1 (p <0,05). Em ratos G4, tratados com L-NAME + Rut-bpy, a PAM atingiu 149±11 milímetros de Hg, enquanto no G2 (ratos tratados com Rut bpy) os valores da PAM foram 106 ±11 mm Hg. No G1 esses valores decresceram progressivamente, atingindo 87±14 mm Hg após 30 minutos. Um achado importante foi a manutenção da PAM durante todo o experimento em ratos do grupo G2. CONCLUSÃO: O uso de Rut bpy não diminui a PAM em ratos hipertensos por L-NAME. No entanto, quando ele é usado em ratos anestesiados, hipotensos, uma pressão arterial estável é obtida