INFLUÊNCIA DA MASSA ESPECÍFICA APARENTE DA MADEIRA NO RUÍDO PRODUZIDO DURANTE O PROCESSAMENTO SECUNDÁRIO: ESTUDO DE CASO

This research had as objective to analyze the noise produced during the secondary processing of distinct woods and its correlation with the mass specifies apparent. The used species were kiri (Paulpwnia sp), eucalipto1 (Eucalyptus grandis versus E. urophylla (híbrido urograndis)), eucalipto2 (Eucalyptus sp), angelim pedra (Hymenolobium petratum), cedro (Cedrela fissilis) e paraju (Manilkara sp.). The mass specifies apparent and moisture content of woods were determinate by norm MB26/1940 (ABNT) and to ergonomic analysis of noise was evaluated according to NR15 (Ministério do Trabalho). The chosen machines for analysis: cutter, buzzy saw, smoother, planer, tape saw and sander. It had significant difference in the study of noise level made by six machines with six woods at 5% of significance, moreover it was verified that the operator is exposed to an average noise level of 86.5 dB(A). The comparison tests of averages were parameters to evidence statistical differences between machines and wood mass specifies apparent, also to verify that noise levels produced by machines there was no statistically difference. It was investigated the woods interaction on the same machine; as a result, the noise produced by cutter was so high with all woods which there was not statistical difference.Esta pesquisa teve como objetivo analisar o ruído produzido durante o processamento de distintas madeiras e a sua correlação com a massa específica aparente. As espécies utilizadas foram kiri (Paulownia sp.), eucalipto1 (Eucalyptus grandis versus E. urophylla (híbrido urograndis)), eucalipto 2 (Eucalyptus sp.), angelim-pedra (Hymenolobium petraeum), cedro (Cedrela fissilis) e paraju (Manilkara sp.). Para a determinação da massa específica aparente e da umidade das madeiras, utilizou-se a norma MB26/1940 da ABNT, e para a análise do ruído, utilizou-se a NR15 do Ministério do Trabalho e Emprego. As máquinas utilizadas foram: serra circular, desempenadeira, desengrossadeira, serra de fita, lixadeira de fita e destopadeira. Houve diferença significativa no estudo do nível de ruído provocado pelas seis máquinas com as seis madeiras a 5% de significância. Verificou-se que o operador fica submetido a um nível médio de ruído de 86,5 dB(A). Os testes de comparação de médias serviram para mostrar diferenças estatísticas entre as máquinas e a massa específica aparente das madeiras e para se verificar que os níveis de ruído emitidos pelas máquinas podem não diferir estatisticamente. O estudo da interação das madeiras nos níveis das máquinas indicou que a destopadeira gera um nível de ruído tão intenso que não há diferença entre as madeiras testadas

Mate (Ilex paraguariensis) as an etiological agent of neoplasia in the aerodigestive tract an experimental study

Existem estudos que consideram o “chimarrão” como fator de risco para desenvolvimento do câncer de orofaringe, esôfago e laringe (infusão de erva mate, Ilex paraguariensis). Comparar a histologia do trato aéro-digestivo de ratos submetidos ao consumo de erva mate Ilex paraguariensis, com um grupo controle. Setenta e cinco ratos Wistar adultos foram testados, 60 bebendo mate na temperatura ambiente e 15 bebendo água (grupo controle), durante 5 meses. A histologia do trato aéro-digestivo destes animais foi analisada. Os animais apresentaram alterações nos exames anátomo-patológicos havendo diferença significativa (p=0,02) entre os que tomaram mate e o grupo controle. Houve diferença estatística entre o peso corporal dos grupos em estudo e o grupo controle (p<0,001). Este estudo indica que o consumo de mate afeta o trato aerodigestivo superior e é responsável pela perda de peso dos animais estudados.There are studies that consider drinking “chimarrão” (an infusion of mate, Ilex paraguariensis) a risk factor for developing oropharynx, esophagus and larynx cancer. To make a histological comparison between the aerodigestive tracts of a group of rats submitted to the consumption of erva-mate Ilex paraguariensis, with a control group. Seventy-five adult Wistar rats were tested, 60 drinking mate at room temperature and 15 drinking water (control group), during a period of 5 months. The histology of the aerodigestive tracts of these animals was analyzed. The animals presented alterations in the anatomical-pathological exams. There was a significant difference (p=0.02) between those that were given mate and the control group. There is evidence to suggest that the consumption of mate affects the upper aerodigestive tract in the animals studied, but not inducing cancer

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

An estimate of the number of tropical tree species

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼40,000 and ∼53,000, i.e. at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼19,000–25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼4,500–6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa