Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

One sixth of Amazonian tree diversity is dependent on river floodplains

Amazonia’s floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region’s floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon’s tree diversity and its function

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia

Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state

Involvement of N-methyl-d-aspartate glutamate receptor and nitric oxide in cardiovascular responses to dynamic exercise in rats

Dynamic exercise evokes sustained cardiovascular responses, which are characterized by arterial pressure and heart rate increases. Although it is well accepted that there is central nervous system mediation of cardiovascular adjustments during exercise, information on the role of neural pathways and signaling mechanisms is limited. It has been reported that glutamate, by acting on NMDA receptors, evokes the release of nitric oxide through activation of neuronal nitric oxide synthase (nNOS) in the brain. In the present study, we tested the hypothesis that NMDA receptors and nNOS are involved in cardiovascular responses evoked by an acute bout of exercise on a rodent treadmill. Moreover, we investigated possible central sites mediating control of responses to exercise through the NMDA receptor-nitric oxide pathway. Intraperitoneal administration of the selective NMDA glutamate receptor antagonist dizocilpine maleate (MK-801) reduced both the arterial pressure and heart rate increase evoked by dynamic exercise. Intraperitoneal treatment with the preferential nNOS inhibitor 7-nitroindazole reduced exercise-evoked tachycardiac response without affecting the pressor response. Moreover, treadmill running increased NO formation in the medial prefrontal cortex (MPFC), bed nucleus of the stria teminalis (BNST) and periaqueductal gray (PAG), and this effect was inhibited by systemic pretreatment with MK-801. Our findings demonstrate that NMDA receptors and nNOS mediate the tachycardiac response to dynamic exercise, possibly through an NMDA receptor-NO signaling mechanism. However, NMDA receptors, but not nNOS, mediate the exercise-evoked pressor response. The present results also provide evidence that MPFC, BNST and PAG may modulate physiological adjustments during dynamic exercise through NMDA receptor-NO signaling. © 2013 Elsevier B.V

Movement disorders secondary to long-term treatment with cyclosporine A Transtornos do movimento secundários ao tratamento prolongado com ciclosporina A

OBJECTIVE: To analyze the prevalence, severity and functional interference of movement disorders (MD) secondary to chronic use of cyclosporine A (CsA). METHOD: We conducted a cross-sectional study of 60 patients (58.3% male) with mean age 23.1 (3-75) years, followed at the Bone Marrow Transplantation Service of the Hospital de Clínicas of the Federal University of Paraná, Brazil, taking CsA for at least six months. Our protocol included clinical data, assessment of functional interference of symptoms and neurological examination including observation and grading of MD. RESULTS: Eight (13.3%) subjects reported the presence of tremor at the moment of interview and 29 (48.3%) recalled this symptom at some point during treatment. Neurological examination identified 14 (23.3%) subjects with MD: upper limb symmetric action tremor in 13 (21.6%) and parkinsonism (rigidity and bradykinesia) in 1 (1.7%). No other MD was detected. The mean scores indicated mild clinical signs in all cases. Symptoms were considered subjectively mild with no functional interference. CONCLUSION: Almost one quarter of patients using CsA chronically presented MD, almost always mild and transitory action tremor, with minimal interference on daily living activities, not requiring any form of intervention in the majority of cases.OBJETIVO: Analisar a prevalência, gravidade e interferência funcional de transtornos do movimento (TM) secundários ao uso crônico de ciclosporina A (CsA). MÉTODO: Realizamos um estudo transversal em 60 pacientes (58.3% do sexo masculino) com idade média de 23.1 (3-75) anos, acompanhados pelo Serviço de Transplante de Medula Óssea do Hospital de Clínicas da Universidade Federal do Paraná, usando CsA por pelo menos seis meses. A avaliação incluiu dados clínicos, interferência funcional de possíveis sintomas e exame neurológico incluindo observação e graduação de TM. RESULTADOS: Oito (13.3%) entrevistados relataram tremor no momento da entrevista e 29 (48.3%) em alguma fase do tratamento. O exame neurológico identificou 14 (23.3%) pacientes com TM: 13 (21.6%) tremor de ação simétrico de membros superiores e em 1 (1.7%) parkinsonismo (rigidez e bradicinesia). Nenhum outro TM foi detectado. Os escores médios indicaram quadros leves em todos os casos. Os sintomas foram também considerados subjetivamente leves e sem interferência funcional. CONCLUSÃO: Quase um quarto dos pacientes usando CsA cronicamente apresenta TM, quase sempre tremor de ação leve e transitório, interferindo pouco funcionalmente, não requerendo intervenção na maioria dos casos

Seismic record of a cyclic turbidite-contourite system in the Northern Campos Basin, SE Brazil

Highlights • A new description of a non-synchronous Mixed Turbidite-Contourite System. • Alternated and cyclic deposits of down-slope and along-slope processes with a transitional stage of flow interaction. • Dominant flow depositional systems identification based on seismic response. • How mixed systems are organized through time and space. Abstract A new mixed turbidite-contourite system is described in the northern Campos Basin, southeastern Brazilian margin. This system is developed in a middle slope setting, and was formed through non-synchronous interaction between the turbidity current and a contour current in the same stratigraphic interval (Miocene). Depositional cycles were differentiated based on diagnostic seismic features. Seismic attributes, seismic facies, and isochron maps were used to identify alternating cycles of downslope and alongslope processes in the study area, along with the intermediate stage with features from both processes (mixed system). Seismic units were then associated with the dominant type of current. Alongslope current activity can be distinguished from the downslope current based on its acoustic characteristics (mainly low root-mean-square (RMS) amplitude values), internal architecture (clinoforms), and external geometry pattern (alongslope trend). On the other hand, downslope gravity currents develop deposits with high-amplitude or chaotic seismic facies, usually higher values of RMS amplitude, channel or channel-lobe features, erosive surfaces, and a basinward depositional trend. The first and oldest seismic unit (S1) was interpreted as a dominantly alongslope system, with vertical aggrading sigmoidal clinoforms and high-frequency, low-amplitude reflections commonly associated with fine-grained sedimentary deposits, typical of a plastered drift, along with a basinward mass transport deposit (MTD) from previous drift instability. Seismic unit S2 represents the intermediate stage where both gravity-driven and along-slope currents act asynchronously. Its is refered to as a mixed turbidite-contourite sequence that shows high-amplitude sediment waves migrating upslope and a moat feature that is carved in its upslope front. The interfingering between high- and low-amplitude reflectors, distal chaotic facies, together with sediment waves and a channel moat, points to a sand-rich deposit reworked by northward-flowing contour currents. Seismic units S3 and S4 show downslope features with chaotic facies (S3) and paleochannels with coarse basal lag deposits (high RMS amplitude values) (S4). In S4, a series of long-lived submarine channels formed. Last, seismic unit S5, referred to as the second plastered drift sequence, is marked by low-amplitude clinoforms that thin basinward. At the seafloor, submarine channel banks (formed at S4) covered by fine sediment deposits (from S5) show asymmetrical features with a slight northward depositional trend, indicating a northward-flowing bottom current, as the deposits are known to pile up in a downcurrent trend. Important information on the paleocurrents' direction was also made based on the final deposits display (e.g. terraces, sediment waves, paleochannels). Research on alternating dominant processes and transitional stages or mixed depositional systems, with both turbidites and contour currents, may provide a better understanding of deep-water depositional processes. Because these processes do not always fit previous depositional models that are mainly described for synchronous systems, new insights on cyclic non-synchronous mixed systems can improve our understanding of how mixed systems are organized through time and space. Being able to determine which were the dominant processes that controlled the sedimentation by indicating periods where the margin was mostly submitted to sediment transfer from continent to the basin and periods where the oceanic currents prevailed by redistributing sediments along the isobaths and replacing the axis of downslope transfer conduits. Setting new models on cyclic deposits and intermediate stages can have a future economic impact on potential hydrocarbon reservoir architecture

Reversible posterior leucoencephalopathy syndrome associated with bone marrow transplantation Leucoencefalopatia posterior reversível associada a transplante de medula óssea

Reversible posterior leucoencephalopathy syndrome (RPLS) has previously been described in patients who have renal insufficiency, eclampsia, hypertensive encephalopathy and patients receiving immunosuppressive therapy. The mechanism by which immunosuppressive agents can cause this syndrome is not clear, but it is probably related with cytotoxic effects of these agents on the vascular endothelium. We report eight patients who received cyclosporine A (CSA) after allogeneic bone marrow transplantation or as treatment for severe aplastic anemia (SSA) who developed posterior leucoencephalopathy. The most common signs and symptoms were seizures and headache. Neurological dysfunction occurred preceded by or concomitant with high blood pressure and some degree of acute renal failure in six patients. Computerized tomography studies showed low-density white matter lesions involving the posterior areas of cerebral hemispheres. Symptoms and neuroimaging abnormalities were reversible and improvement occurred in all patients when given lower doses of CSA or when the drug was withdrawn. RPLS may be considered an expression of CSA neurotoxicity.<br>A síndrome de leucoencefalopatia posterior reversível (SLPR) tem sido descrita em pacientes com insuficiência renal, eclâmpsia, encefalopatia hipertensiva e em pacientes que recebem terapia imunossupressora. O mecanismo pelo qual os agentes imunossupressores podem causar a síndrome ainda não são conhecidos, porém estão provavelmente relacionados aos efeitos citotóxicos destes agentes no endotélio vascular. Relatamos oito pacientes que receberam ciclosporina A (CSA) após transplante de medula óssea alogênico ou para tratamento de anemia aplástica severa e que desenvolveram a SLPR. Os sinais e sintomas mais comuns foram convulsões e cefaléia. A disfunção neurológica ocorreu simultaneamente ou precedida por elevação da pressão arterial sistêmica e disfunção renal aguda em seis pacientes. O exame de tomografia computadorizada do crânio demonstrou a presença de áreas de baixos valores de atenuação na distribuição da substância branca, envolvendo áreas posteriores de ambos os hemisférios cerebrais. O quadro clínico e as anormalidades tomográficas foram reversíveis; a melhora ocorreu em todos os pacientes em que as doses de CSA foram reduzidas ou quando a droga foi retirada. A SLPR pode ser considerada uma expressão de neurotoxicidade da CSA