Fouling organisms on Perna perna mussels: is it worth removing them?

Perna perna mussel spat were suspended from ropes on a long-line cultivation, at Coqueiro´s Beach, Anchieta, South-eastern Brazil, in order to quantify the fouling community structure and its effects on growth and biomass of mussels. Half of the ropes had the fouling removed monthly, half had the foulingleft until the end of the experiment. Monthly samples of thirty mussels from each group were measured and their biomass determined. The fouling organisms were identified, quantified and their biomass evaluated on a monthly basis. After ten months, mussels on the cleaned treatment were significantly larger and heavier (ANOVA; P ; fouled), showing that fouling reduced mussel development. The most abundant epibiont organisms in terms of biomass were the algae Polysiphonia subtilissima (29%) and Ulva rigida (10.3%), followed by the bryozoans Bugula neritina (13.6%) and Perna perna spat (10.6%). Over 97 taxa and 42,646 individuals were identified, crustaceans being the most abundant group, predominantly one amphipod Cheiriphotis megacheles (12,980 ind.). Species abundance was positively correlated with algal biomass, revealing the influence of algae on vagile fauna, which provide both food and shelter. The benefits of fouling removal are discussed because the majority of species are important feeding items to fishes and yet, the costs of its fouling control added to the associated mussel spat loss make this fouling removal of questionable value.Sementes de Perna perna foram colocadas em cordas suspensas em long-line na Praia do Coqueiro, Anchieta, ES, objetivando-se determinar a estrutura da comunidade de incrustantes e seu efeito sobre o desenvolvimento dos mexilhões. Metade das cordas teve os incrustantes removidos mensalmente, na outra metade eles foram deixados até o final do experimento. Mensalmente, 30 mexilhões de cada grupo foram retirados e medidos e a biomassa aferida. Os incrustantes foram identificados, quantificados e a biomassa de cada taxon determinada. Após 10 meses de cultivo, os mexilhões sem incrustantes eram significativamente maiores e mais pesados (ANOVA; P ; com incrustantes), demonstrando que os incrustantes interferiram negativamente no desenvolvimento dos mexilhões. Os incrustantes mais abundantes em termos de biomassa foram as algas Polysiphonia subtilissima (29%) e Ulva rigida (10,3%), seguidas pelos briozoários Bugula neritina (13,6%) e sementes de Perna perna (10,6%). Foram registrados 97 taxa e 42.646 indivíduos, sendo Crustacea o grupo mais abundante, principalmente o anfípodo Cheiriphotis megacheles (12.980 ind.). A abundância de indivíduos foi positivamente correlacionada com a biomassa de algas, revelando a influência das algas na fauna vágil, provendo abrigo e alimentação. Os benefícios da remoção dos incrustantes são discutidos, uma vez que a maioria dos incrustantes são importantes como itens alimentares para os peixes; além disso, os custos desta remoção somados à perda de sementes de mexilhões, tornam a remoção desta comunidade de incrustantes questionável

Evaluation of hypoglycemic potential and pre-clinical toxicology of Morus nigra L. (Moraceae)

The hypoglycemic potential of crude ethanolic extract of leaves (CEE-Mn) of the Morus nigra L. (Moraceae) was evaluated in normoglycemic rats. CEE-Mn (200 and 400 mg/kg) and metformin (500 mg/kg) were tested on the glucose tolerance oral test. The acute toxicity of CEE-Mn was performed 2.0 g/kg intraperitoneally and 5.0 g/kg orally in Swiss mice. Blood was removed after seven days for laboratory analysis of hematological and biochemical parameters. In the glucose tolerance oral test, only metformin was able to reduce the glucose-induced hyperglycemia. Regarding acute toxicity no mortality and no toxicity signs were observed, indicating low toxicity of the extract. In the evaluation of hematological and biochemical parameters no alteration was observed. In conclusion, the CEE-Mn can be considered of low toxicity but did not produce the expected hypoglycemic effect in the model used.Colegio de Farmacéuticos de la Provincia de Buenos Aire

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

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

Optimization of Thermomechanical Processing under Double-Pass Hot Compression Tests of a High Nb and N-Bearing Austenitic Stainless-Steel Biomaterial Using Artificial Neural Networks

Physical simulation is a useful tool for examining the events that occur during the multiple stages of thermomechanical processing, since it requires no industrial equipment. Instead, it involves hot deformation testing in the laboratory, similar to industrial-scale processes, such as controlled hot rolling and forging, but under different conditions of friction and heat transfer. Our purpose in this work was to develop an artificial neural network (ANN) to optimize the thermomechanical behavior of stainless-steel biomaterial in a double-pass hot compression test, adapted to the Arrhenius–Avrami constitutive model. The method consists of calculating the static softening fraction (Xs) and mean recrystallized grain size (ds), implementing an ANN based on data obtained from hot compression tests, using a vacuum chamber in a DIL 805A/D quenching dilatometer at temperatures of 1000, 1050, 1100 and 1200 °C, in passes (ε1 = ε2) of 0.15 and 0.30, a strain rate of 1.0 s−1 and time between passes (tp) of 1, 10, 100, 400, 800 and 1000 s. The constitutive analysis and the experimental and ANN-simulated results were in good agreement, indicating that ASTM F-1586 austenitic stainless steel used as a biomaterial undergoes up to Xs = 40% of softening due solely to static recovery (SRV) in less than 1.0 s interval between passes (tp), followed by metadynamic recrystallization (MDRX) at strains greater than 0.30. At T > 1050 °C, the behavior of the softening curves Xs vs. tp showed the formation of plateaus for long times between passes (tp), delaying the softening kinetics and modifying the profile of the curves produced by the moderate stacking fault energy, γsfe = 69 mJ/m2 and the strain-induced interaction between recrystallization and precipitation (Z-phase). Thus, the use of this ANN allows one to optimize the ideal thermomechanical parameters for distribution and refinement of grains with better mechanical properties

Colônia do Sacramento: a situação na fronteira platina no século XVIII

A Colônia do Sacramento, no atual Uruguai, na primeira metade do século XVIII, constituiu uma cidade de pródigo comércio na região platina. Inseridos tanto nas rotas comerciais e sociais portuguesas quanto nas castelhanas, os habitantes de Sacramento materializavam uma fronteira múltipla, onde coexistiam espanhóis, portugueses e diferentes grupos indígenas. O presente estudo analisa os vínculos sociais e comerciais existentes entre os habitantes de Sacramento e os de Buenos Aires. No interior do espaço platino as redes sociais estabelecidas através do rio da Prata, ligando Sacramento e Buenos Aires, eram vias de acúmulo de prestígio, poder e riqueza em uma sociedade de antigo regime.<br>The Sacramento Colony, currently Uruguayan territory, in the first half of the XVIII century, was a city with great commerce on the River Plate Region. Placed in both Portuguese and Spanish social and commercial routes, the Sacramento habitants formed a multiple frontier where Spanish, Portuguese and different indigenous groups coexisted. The present study analyses the social and commercial links that existed between the Sacramento and Buenos Aires inhabitants. In the River Plate region, the social networks developed connecting Sacramento and Buenos Ayers were gateways to social status, power and wealth in an old regime society