Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications 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, 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

Effect of different exposure times on caries detection and pixel value in a wireless digital system

Objectives: The aim of this study was to assess, using the CDR Wireless®, the effect of different exposure times on caries detection and pixel intensity values. Materials and Methods: Forty teeth were x-rayed using a Schick CDR Wireless sensor at eight different exposure times - 0.06, 0.10, 0.13, 0.16, 0.20, 0.25, 0.30, and 0.32 s. Four observers evaluated the images for presence of carious lesions scoring proximal surfaces of each tooth on a 5-point scale. Scores were compared to histological sections of the teeth. Accuracy was evaluated by means of ROC curve analysis. Radiographs of an aluminum step wedge were obtained using the same eight exposure times. Pixel intensity measurements were obtained, and mean pixel values were statistically analyzed using linear regression. Results: The Az for each exposure time varied from 0.53 to 0.62. Two-way analysis of variance and Tukey test demonstrated that the exposure time of 0.25 s presented the best result and was significantly higher than 0.30 s and 0.35 s. In regard to mean pixel values, two different behaviors were observed, and the exposure time of 0.20 s presented mean pixel values in both phases. Conclusion: The performance of the exposure times from 0.06 s to 0.25 s was satisfactory for proximal caries detection, and 0.25 s is the best as indicated for this finality. Clinical Relevance: Considering that a reduction of exposure time represents a reduction of patient exposure dose, and this reduction cannot neglect image quality, the behavior of any digital system must be carefully evaluated.30566566

Diversity patterns of hawkmoths (Lepidoptera: Sphingidae) in the canopy of an ombrophilous forest in Central Amazon, Brazil

Sphingidae attracted to light were systematically collected in an Amazonian forest canopy. Sampling occurred at a height of 34 m in an upland primary rainforest plateau in the Cueiras River basin, located within the Experimental Station of Tropical Silviculture, Manaus municipality, Amazonas, Brazil. The hawkmoths were collected using a vertical white sheet illuminated by a 250 W mixed mercury light and a 20 W black-light (BLB) fluorescent tube. Monthly collections were carried out from January to December 2004, during three nights of lunar transition from third quarter moon to new moon between 6 p.m. and 6 a.m. We sampled 1748 specimens, represented by 1485 males and 263 females, belonging to 52 species and 21 genera. Xylophanes comprised the highest number of species (seven), followed by Erinnyis, with six species. The most abundant species were Pseudosphinx tetrio (169 specimens), Pachylia darceta (162), Erinnyis ello ello (154), Isognathus excelsior (151) and Callionima parce (139). The species accumulation curve showed that the species richness tended to stabilize by the eighth month. We also observed that species composition altered significantly throughout the night period. All presented hawkmoth records are new for the canopy in the central Amazon.Foram realizadas coletas sistemáticas de Sphingidae no dossel de floresta ombrófila densa na Amazônia central utilizando-se armadilha luminosa. As coletas ocorreram em uma floresta primária de terra firme, na bacia do Rio Cuieiras, a 34 m de altura na torre da Estação Experimental de Silvicultura Tropical, Manaus, Amazonas, Brasil. Foi utilizado um lençol branco iluminado com uma lâmpada de luz mista de mercúrio e uma lâmpada de luz negra UV-BLB. As mariposas foram coletadas mensalmente durante o ano de 2004, em três noites consecutivas de lua minguante e/ou lua nova, sempre das 18:00 às 06:00h. Foram coletados 1748 espécimes, dos quais 769, por serem comuns, foram identificados, marcados e soltos. Foram obtidos 1485 machos e 263 fêmeas, pertencentes a 21 gêneros e 52 espécies. Xylophanes foi representado por sete espécies, seguido por Erinnyis com seis. As espécies mais abundantes foram Pseudosphinx tetrio (169 espécimes), Pachylia darceta (162), Erinnyis ello ello (154), Isognathus excelsior (151) e Callionima parce (139). A curva de acumulação de espécie mostrou que em torno do oitavo mês de coleta, a riqueza de espécies tendeu a estabilizar. Foi possível observar ainda que a composição de esfingídeos mudou significativamente ao longo da noite. Todos os registros são novos para o dossel de floresta na Amazônia central