16 research outputs found
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
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
Short-Term Effects of Land-Based Versus Water-Based Resistance Training Protocols on Post-Exercise Hypotension in Normotensive Men: A Crossover Study
Considering that water immersion may acutely reduce blood pressure (BP) and that exercise may elicit positive post-exercise hypotension (PEH) responses, we aimed to analyze the presence of PEH in normotensive individuals and compare its magnitude between two resistance training sessions performed in aquatic or land environments. Ten physically active men (23.2 ± 3.1 years) performed the two training protocols in a randomized, counterbalanced fashion. BP measurements were performed for 30 min (at 5 min intervals) both prior to (resting) and after each of the protocols. No differences were observed between protocols at baseline (p > 0.05). Only the water-based resistance training protocol resulted in a systolic BP reduction from 10 to 20 min post-exercise (all p p p < 0.001). Our results suggest that water-based resistance training holds the potential as a nonpharmacological strategy to lower BP levels following exercise
Incorporation of wine industry waste into red ceramic: study of physical and mechanical properties
This study examines the potential of adding grape skins to red ceramics to evaluate its effect on the physical and mechanical properties of the clayey body. Five compositions were prepared with different percentages of biomass incorporation: 0%, 2.5%, 5%, 7.5%, and 10%. The specimens were conformed using vacuum extrusion in a laboratory extruder, with dimensions of 120 mm in length and a straight section of 30 × 15 mm. After drying, the pieces were sintered in a laboratory muffle furnace at 700 °C, 800 °C, 900 °C and 1000 °C. Chemical, mineralogical, thermal, physical, morphological, and microscopy tests were conducted on the clayey raw materials. An acceptable formulation was achieved by incorporating up to 5% biomass, fired at 900 °C. For water absorption, the incorporation of up to 5% of biomass fired at 700 °C satisfies the normative limits to produce structural blocks and sealing blocks. From 900 °C onwards, it meets the parameter intended for making roof tiles. The linear shrinkage of the pieces fired up to 900 °C is slightly altered by the incorporation of up to 5% of biomass fired under 800 °C are below 2%. The bending strength, at 700 °C there was an increase in mechanical strength directly proportional to the increase in biomass. However, at 800 and 900 °C, there was a gradual decrease in the bending strength. In turn, at 1000 °C, there was a sudden reduction in bending strenght for all formulations with biomass incorporation
Study of the incorporation of two types of wastes and their combined effects into red ceramics
As the population continues to grow, the consumption of natural resources for use as primary materials in civil construction also increases. In addressing the need to reduce the depletion of natural resources, a viable alternative for the production of civil construction materials involves substituting a portion of these raw materials with waste materials. This approach seeks to achieve two key objectives: the promotion of waste reuse and a reduction in the consumption of natural resources. Amongst these materials, red ceramics is one of the categories of civil construction materials that allow the incorporation of waste, since its raw material, ceramic clay, is intrinsically heterogeneous, which makes the final product capable of containing a certain number of foreign materials. Wastes to be added in ceramic masses are classified, among others, into fuel and flux wastes, and both affect the ceramic firing stage in a different way. Flux wastes facilitate the liquid phase formation and fuel wastes release heat for the process. Thus, this work's main purpose was to study the mechanical behavior of red ceramics incorporated with a mixture of fuel and flux wastes, as well as the incorporation of both separately. The ceramic bodies were prepared in 7 different compositions by uniaxial pressing and were fired at 850 °C and 1050 °C. Then, their technological properties were determined to study the combined effect of adding two different types of waste at the same time. Subsequently, their technological characteristics were assessed to investigate the synergistic impact of simultaneously introducing two distinct waste materials. This study unveiled that the drawbacks associated with the inclusion of fuel waste can be mitigated by incorporating flux waste. This has the potential to enhance the sustainability of the red ceramics industry by yielding a material with properties akin to commercial products while also valorizing two waste streams that would otherwise be wrongly disposed of
Development of Sustainable Artificial Stone Using Granite Waste and Biodegradable Polyurethane from Castor Oil
Brazil is one of the world’s major ornamental stone producers. As a consequence, ornamental stone wastes are generated on a large scale and are usually open air disposed. Thus, it is important to develop novel material reusing these accumulated wastes, aiming to minimize environmental impact. The development of artificial stones made with ornamental stone wastes agglomerated by a synthetic polymer represents an excellent alternative and, therefore, is currently the subject of several works. This work seeks to develop an innovative artificial stone containing 85%wt of granite waste and 15%wt of vegetable polyurethane from castor oil, a biodegradable resin, from a renewable source. The purpose is creating a sustainable material, technically viable to be applied as a civil construction coating. To manufacture the artificial stone plates, granite and polyurethane were mixed and transferred to a metallic mold subjected to vibration, vacuum and, later, hot compression. The artificial stone presented low water absorption (0.13%) and apparent porosity (0.31%) as well as a favorable 17.31 MPa bend strength. These results were confirmed through the excellent particles/matrix adhesion displayed in the micrographs, in addition to great chemical resistance
Flexible artificial stone developed with waste tire and waste glass agglomerated by a biopolymeric resin
Artificial stones are building materials developed with stony waste aggregates and a polymeric resin as an agglomerate. Its mechanical properties, in general, overcome natural stone's properties, since the use of resin makes it possible to manufacture a less porous, that is, a denser material, more impermeable, and with greater mechanical resistance. However, its development is costly because it requires the use of high-quality aggregates. Waste can replace these aggregates, developing an economically and environmentally advantageous novel, sustainable artificial stone. This work's main goal is to develop a flexible sustainable artificial stone based on waste glass and waste tire agglomerated with a biopolymeric resin, polyurethane from castor oil, and evaluate its properties. Plates were manufactured with 22% of polyurethane resin and 78% of different proportions of the two wastes (glass and tire) mixed up. The molding was carried out under a 600 mmHg vacuum, a 6Hz vibration, and an 80° hot pressing for 20 min. The stones developed, named AS50GT and AS66GT, were lighter than other developed artificial stones, but less resistant to bending efforts since rubber tire is a polymeric material. However, they displayed a high Izod impact strength, evidencing that the development of artificial stones with glass and tire wastes and biopolymeric polyurethane resin is viable, not only from an economic and environmental point of view but also technically viable once both developed stones can be marked in the building construction industry
Characterization of Artificial Stone Developed with the Incorporation of Granite and Mirror Wastes in an Epoxy Matrix
The objective of this research was to produce artificial stone plates based on granite and mirror wastes and epoxy matrix, by vibration, compression, and vacuum and to characterize them. Plates were manufactured with 15%wt epoxy resin and 85% of aggregates in the proportion of 1/3 of granite waste from Ocre Itabira gray granite and 2/3 of mirror waste. The apparent density, water absorption, and apparent porosity values were 2.22 g/cm3, 0.11%, and 0.25%, respectively, the flexural strength was 34.36 MPa, abrasive wear after a 1000m track was 2.28mm and the breaking height in the impact resistance test was 0.45m. In addition, the stone was resistant to several staining agents. Therefore, the technical viability of the material developed was verified, with results compatible with studies already carried out in the area, making it possible to apply it as coatings and countertops in civil construction