Forest disturbance and growth processes are reflected in the geographical distribution of large canopy gaps across the Brazilian Amazon

Canopy gaps are openings in the forest canopy resulting from branch fall and tree mortality events. The geographical distribution of large canopy gaps may reflect underlying variation in mortality and growth processes. However, a lack of data at the appropriate scale has limited our ability to study this relationship until now. We detected canopy gaps using a unique LiDAR dataset consisting of 650 transects randomly distributed across 2500 km(2) of the Brazilian Amazon. We characterized the size distribution of canopy gaps using a power law and we explore the variation in the exponent, alpha. We evaluated how the alpha varies across the Amazon, in response to disturbance by humans and natural environmental processes that influence tree mortality rates. We observed that South-eastern forests contained a higher proportion of large gaps than North-western, which is consistent with recent work showing greater tree mortality rates in the Southeast than the Northwest. Regions characterized by strong wind gust speeds, frequent lightning and greater water shortage also had a high proportion of large gaps, indicating that geographical variation in alpha is a reflection of underlying disturbance processes. Forests on fertile soils were also found to contain a high proportion of large gaps, in part because trees grow tall on these sites and create large gaps when they fall; thus, canopy gap analysis picked up differences in growth as well as mortality processes. Finally, we found that human-modified forests had a higher proportion of large gaps than intact forests, as we would expect given that these forests have been disturbed. Synthesis. The proportion of large gaps in the forest canopy varied substantially over the Brazilian Amazon. We have shown that the trends can be explained by geographical variation in disturbance and growth. The frequency of extreme weather events is predicted to increase under climate change, and changes could lead to greater forest disturbance, which should be detectable as an increased proportion of large gaps in intact forests.Peer reviewe

Land use still matters after deforestation

Careful management of deforested Amazonian land cannot replace, but must complement, efforts to preserve the rainforest. Sustainable agricultural practices that promote diverse uses can help minimise climate and environmental impacts.Peer reviewe

Psittacara leucophthalmus as a new host of Paratanaisia bragai (Trematoda: Eucotylidae) in Brazil: clinical and pathological findings: case report

Paratanaisia bragai is a trematode parasite of the kidneys and ureters of poultry and wild birds. Despite its low pathogenicity, this parasite can lead to several clinical complications and death in heavy infections. In the present study, a fatal case of parasitism by P. bragai in a specimen of the White-eyed Parakeet, Psittacara leucophthalmus, is reported. The bird, coming from the urban area of the county of Lavras, Minas Gerais, Brazil, was clinically evaluated and revealed apathy, dehydration, dyspnea, and death. The gross findings were pale and enlarged kidneys, which also had irregular surface with whitish nodulations. Parasites were observed on cutting surface of the renal parenchyma. They were processed for assembly of permanent slides and identified as P. bragai according to routine technique. The histologic findings were mild multifocal lymphoplasmacytic infiltrate, tubular dilatation and foci of tubular regeneration related to mild interstitial fibrosis in the renal cortex, and infiltration of macrophages, heterophils, eosinophils and multinucleated giant cells associated with metazoan parasites in the collecting ducts in renal medulla. The parasitism of P. leucophthalmus by P. bragai is reported for the first time. The importance of considering this parasite among the diagnostic possibilities in birds with renal insufficiency is briefly discussed.Paratanaisia bragai é um trematódeo que parasita rins e ureteres de aves domésticas e selvagens. Apesar de considerado pouco patogênico pode levar a complicações clínicas e morte em infecções severas. No presente estudo, um caso de parasitismo fatal em maritaca (Psittacara leucophthalmus) por P. bragai é relatado. A ave, oriunda da área urbana do município de Lavras, Minas Gerais, Brasil, teve manifestações clínicas de apatia, desidratação, dispneia e veio a óbito. Na necropsia foram observados rins aumentados de volume, pálidos, com superfície irregular e nodulações esbranquiçadas. Ao corte verificaram-se parasitos nos rins, que foram processados para montagem de lâminas permanentes e identificados segundo técnica de rotina como P. bragai. No exame histopatológico dos rins foram constatados infiltrado inflamatório linfoplasmocítico multifocal moderado, dilatação de túbulos e focos de regeneração tubular, associados a fibrose intersticial moderada no córtex renal. Na medula renal havia infiltrado de macrófagos, heterófilos, eosinófilos e células gigantes multinucleadas associado a parasitos em ductos coletores dilatados. O parasitismo de P. leucophthalmus por P. bragai é relatado pela primeira vez. A importância de se considerar este parasito entre as possibilidades diagnósticas em aves com insuficiência renal é brevemente discutida.FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerai

Fibroblast Growth Factor 2 lethally sensitizes cancer cells to stress-targeted therapeutic inhibitors.

In malignant transformation, cellular stress response pathways are dynamically mobilized to counterbalance oncogenic activity, keeping cancer cells viable. Therapeutic disruption of this vulnerable homeostasis might change the outcome of many human cancers, particularly those for which no effective therapy is available. Here, we report the use of Fibroblast Growth Factor 2 (FGF2) to demonstrate that further mitogenic activation disrupts cellular homeostasis and strongly sensitizes cancer cells to stress-targeted therapeutic inhibitors. We show that FGF2 enhanced replication and proteotoxic stresses in a K-Ras-driven murine cancer cell model, and combinations of FGF2 and proteasome or DNA damage response-checkpoint inhibitors triggered cell death. CRISPR/Cas9-mediated K-Ras depletion suppressed the malignant phenotype and prevented these synergic toxicities in these murine cells. Moreover, in a panel of human Ewing's sarcoma family tumor cells, sub-lethal concentrations of bortezomib (proteasome-inhibitor) or VE-821 (ATR-inhibitor) induced cell death when combined with FGF2. Sustained MAPK-ERK1/2 overactivation induced by FGF2 appears to underlie these synthetic lethalities, as late pharmacological inhibition of this pathway restored cell homeostasis and prevented these described synergies. Our results highlight how mitotic signaling pathways frequently overridden in malignant transformation might be exploited to disrupt the robustness of cancer cells, ultimately sensitizing them to stress-targeted therapies. This approach provides a new therapeutic rationale for human cancers, with important implications for tumors still lacking effective treatment, and for those that frequently relapse after treatment with available therapies

Achados patológicos em caninos com displasia renal no Sul do Brasil

A displasia renal resulta de um distúrbio na nefrogênese, com diferenciação anormal dos rins, podendo ser unilateral ou bilateral, e causa insuficiência renal em cães jovens. Qualquer agente agressor, incluindo vírus, pode causar a lesão até três meses após o nascimento, quando encerra o desenvolvimento embrionário do néfron. Foram diagnosticados 11 casos de displasia renal dentre 186 casos de cães com insuficiência renal de um total de 5.846 cães submetidos à necropsia no Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul no período 2002-2013. Amostras teciduais coletadas na necropsia foram fixadas em 10% de formol e coradas com hematoxilina e eosina (HE) e tricrômico de Masson. Na necropsia, os rins estavam pálidos, diminuídos de tamanho, irregulares e firmes, com diâmetro da cortical diminuído. Alguns ainda eram císticos e apresentavam estriações brancacentas paralelas dispostas radialmente na medular. Ao exame histológico os rins exibiam lesões primárias e secundárias. As lesões primárias identificadas foram glomérulos e túbulos fetais, diminuição quantitativa de glomérulos, túbulos adenomatosos e persistência de ductos metanéfricos. Dentre as lesões secundárias, a coloração de tricrômico de Masson evidenciou intensa fibrose intersticial em todos os casos. Além disso, foram observadas dilatação de túbulos e da cápsula de Bowman, atrofia glomerular e glomeruloesclerose. Ainda que a maioria dos casos tenha sido relacionada com linhagens raciais, esse trabalho demonstra uma alta frequência de diagnóstico de displasia renal em cães sem raça definida, possivelmente devido ao fato de que estes representam a maioria dos cães encaminhados ao laboratório. Apesar das lesões primárias serem facilmente identificadas pela coloração de hematoxilina eosina, a coloração de tricrômico de Masson auxilia na identificação da extensão da fibrose

Induction of Heme Oxygenase-1 Can Halt and Even Reverse Renal Tubule-Interstitial Fibrosis

Background: The tubule-interstitial fibrosis is the hallmark of progressive renal disease and is strongly associated with inflammation of this compartment. Heme-oxygenase-1 (HO-1) is a cytoprotective molecule that has been shown to be beneficial in various models of renal injury. However, the role of HO-1 in reversing an established renal scar has not yet been addressed. Aim: We explored the ability of HO-1 to halt and reverse the establishment of fibrosis in an experimental model of chronic renal disease. Methods: Sprague-Dawley male rats were subjected to unilateral ureteral obstruction (UUO) and divided into two groups: non-treated and Hemin-treated. To study the prevention of fibrosis, animals were pre-treated with Hemin at days -2 and -1 prior to UUO. To investigate whether HO-1 could reverse established fibrosis, Hemin therapy was given at days 6 and 7 post-surgery. After 7 and/or 14 days, animals were sacrificed and blood, urine and kidney tissue samples were collected for analyses. Renal function was determined by assessing the serum creatinine, inulin clearance, proteinuria/creatininuria ratio and extent of albuminuria. Arterial blood pressure was measured and fibrosis was quantified by Picrosirius staining. Gene and protein expression of pro-inflammatory and pro-fibrotic molecules, as well as HO-1 were performed. Results: Pre-treatment with Hemin upregulated HO-1 expression and significantly reduced proteinuria, albuminuria, inflammation and pro-fibrotic protein and gene expressions in animals subjected to UUO. Interestingly, the delayed treatment with Hemin was also able to reduce renal dysfunction and to decrease the expression of pro-inflammatory molecules, all in association with significantly reduced levels of fibrosis-related molecules and collagen deposition. Finally, TGF-beta protein production was significantly lower in Hemin-treated animals. Conclusion: Treatment with Hemin was able both to prevent the progression of fibrosis and to reverse an established renal scar. Modulation of inflammation appears to be the major mechanism behind HO-1 cytoprotection.Fundacao de Amparo Pesquisa do Estado de Sao Paulo-FAPESP[07/07139-3]Coordenaco de Aperfeioamento de Pessoal de Nivel Superior-CAPESInstituto Nacional de Ciencia e Tecnologia de Complexos Fluidos (INCT)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNP

Use of LST images from MODIS/AQUA sensor as an indication of frost occurrence in RS

ABSTRACTAlthough frost occurrence causes severe losses in agriculture, especially in the south of Brazil, the data of minimum air temperature (Tmin) currently available for monitoring and predicting frosts show insufficient spatial distribution. This study aimed to evaluate the MDY11A1 (LST – Land Surface Temperature) product, from the MODIS sensor on board the AQUA satellite as an estimator of frost occurrence in the southeast of the state of Rio Grande do Sul, Brazil. LST images from the nighttime overpass of the MODIS/AQUA sensor for the months of June, July and August from 2006 to 2012, and data from three conventional weather stations of the National Institute of Meteorology (INMET) were used. Consistency was observed between Tmin data measured in weather stations and LST data obtained from the MODIS sensor. According to the results, LSTs below 3 ºC recorded by the MODIS/AQUA sensor are an indication of a favorable scenario to frost occurrence

Neoplasmas oculares e de anexos em cães e gatos no Rio Grande do Sul: 265 casos (2009 -2014)

Neoplasias oculares causam desconforto, problemas de visão e podem refletir doenças sistêmicas. Um estudo retrospectivo foi realizado para identificar e analisar neoplasmas oculares e de anexos obtidos por biópsias enviadas ao Setor de Patologia Veterinária (SPV) da Universidade Federal do Rio Grande do Sul (UFRGS). Durante o período de janeiro de 2009 a dezembro de 2014 realizou-se 265 diagnósticos de neoplasmas oculares e de anexos, destes 87,5% na espécie canina e em 12,5% na espécie felina. As neoplasias ocorreram mais em animais com idade superior a 12 meses e idosos, e os cães (52/232) e gatos (21/33) sem raça definida foram os mais acometidos. A pálpebra foi o local mais acometido na espécie canina (164/232) e felina (20/33), seguida pela terceira pálpebra em cães (20/232) e órbita nos felinos (5/33). O tumor mais diagnosticado nos cães foi o adenoma meibomiano (82/232) e nos gatos o carcinoma de células escamosas (10/33), ambos em pálpebras. Foram identificados nos cães 24 tipos tumorais e nos gatos 16. Em caninos as neoplasias benignas representaram o maior número de diagnósticos (56%) sendo que em felinos o maior número de casos foi de neoplasias malignas (75,8%)