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1.
Proc Natl Acad Sci U S A ; 121(22): e2317563121, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38771875

RESUMO

Private donors contributed more than $350 million to local election officials to support the administration of the 2020 election. Supporters argue these grants were neutral and necessary to maintain normal election operations during the pandemic, while critics worry these grants mostly went to Democratic strongholds and tilted election outcomes. How much did these grants shape the 2020 presidential election? To answer this question, we collect administrative data on private election administration grants and election outcomes. We then use advances in synthetic control methods to compare presidential election results and turnout in counties that received grants to counties with similar election results and turnout before 2020. While Democratic counties were more likely to apply for a grant, we find that the grants did not have a noticeable effect on the presidential election. Our estimates of the average effect on Democratic vote share range from 0.03 to 0.36 percentage points. Our estimates of the average effect of receiving a grant on turnout range from 0.03 to 0.14 percentage points. Across specifications, our 95% CIs typically include negative effects and all fail to include effects on Democratic vote share larger than 0.58 percentage points and effects on turnout larger than 0.40 percentage points. We characterize the magnitude of our effects by asking how large they are compared to the margin by which Biden won the 2020 election. In simple bench-marking exercises, we find that the effects of the grants were likely too small to have changed the outcome of the 2020 presidential election.


Assuntos
Política , Humanos , Estados Unidos , COVID-19/economia , COVID-19/epidemiologia , Pandemias/economia , Organização do Financiamento
2.
Proc Natl Acad Sci U S A ; 120(43): e2221342120, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37844249

RESUMO

The resurgence in space activities we are witnessing may provide opportunities for new technologies to generate potential spillovers to the real economy. To address this view, we propose a macroeconomic model with endogenous growth and a space sector. The model describes the relationship between space investment and technological spillovers, which support persistent economic growth. Our estimates indicate that space activities provide growth spillovers that peak from the late 1960s to the early 1980s. Recent space activities have a much lower economic impact. Finally, extensive experiments quantify the economic relevance of our results.

3.
Proc Natl Acad Sci U S A ; 120(14): e2217698120, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-36996111

RESUMO

The use of strong acids and low atom efficiency in conventional hydrometallurgical recycling of spent lithium-ion batteries (LIBs) results in significant secondary wastes and CO2 emissions. Herein, we utilize the waste metal current collectors in spent LIBs to promote atom economy and reduce chemicals consumption in a conversion process of spent Li1-xCoO2 (LCO) → new LiNi0.80Co0.15Al0.05O2 (NCA) cathode. Mechanochemical activation is employed to achieve moderate valence reduction of transition metal oxides (Co3+→Co2+,3+) and efficient oxidation of current collector fragments (Al0→Al3+, Cu0→Cu1+,2+), and then due to stored internal energy from ball-milling, the leaching rates of Li, Co, Al, and Cu in the ≤4 mm crushed products uniformly approach 100% with just weak acetic acid. Instead of corrosive precipitation reagents, larger Al fragments (≥4 mm) are used to control the oxidation/reduction potential (ORP) in the aqueous leachate and induce the targeted removal of impurity ions (Cu, Fe). After the upcycling of NCA precursor solution to NCA cathode powders, we demonstrate excellent electrochemical performance of the regenerated NCA cathode and improved environmental impact. Through life cycle assessments, the profit margin of this green upcycling path reaches about 18%, while reducing greenhouse gas emissions by 45%.

4.
Proc Natl Acad Sci U S A ; 120(46): e2306902120, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37934823

RESUMO

Plastic recycling presents a vexing challenge. Mechanical recycling offers substantial greenhouse gas emissions savings relative to virgin plastic production but suffers from degraded aesthetic and mechanical properties. Polypropylene, one of the most widely used and lowest-cost plastics, features methyl pendants along the polymer backbone, rendering it particularly susceptible to declining properties, performance, and aesthetics across a succession of mechanical recycles. Advanced processes, such as solvent-assisted recycling, promise near-virgin quality outputs at a greater energy and emissions footprint. Mechanical and advanced recycling are often presented as competing options, but real-world plastic waste streams are likely to require preprocessing regardless of whether they are routed to an advanced process. This study quantifies the life-cycle greenhouse gas implications of multiple recycling strategies and proposes a system in which mechanical and solvent-assisted recycling can be leveraged together to boost recycling rates and satisfy demand for a wider range of product applications. Polypropylene can be recovered from mixed-plastic bales produced at material recovery facilities and processed through mechanical recycling, with a varying fraction sent for further upgrading via solvent-assisted recycling to produce material approved for food packaging and other higher-quality applications. The resulting mechanically recycled rigid polypropylene reduces life-cycle greenhouse gas emissions by 80% relative to the same quantity of virgin material, while the upgraded higher-quality material achieves GHG savings of 30%.

5.
Proc Natl Acad Sci U S A ; 120(52): e2312962120, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38109547

RESUMO

After 500 y of colonizing the forest-steppe area northwest of the Black Sea, on the territories of what is today Moldova and Ukraine, Trypillia societies founded large, aggregated settlements from ca. 4150 BCE and mega-sites (>100 ha) from ca. 3950 BCE. Covering up to 320 ha and housing up to 15,000 inhabitants, the latter were the world's largest settlements to date. Some 480 δ13C and δ15N measurements on bones of humans, animals, and charred crops allow the detection of spatio-temporal patterns and the calculation of complete agricultural Bayesian food webs for Trypillia societies. The isotope data come from settlements of the entire Trypillia area between the Prut and the Dnieper rivers. The datasets cover the development of the Trypillia societies from the early phase (4800-4200/4100 BCE), over the agglomeration of mega-sites (4200/4100-3650 BCE), to the dispersal phase (3650-3000 BCE). High δ15N values mostly come from the mega-sites. Our analyses show that the subsistence of Trypillia mega-sites depended on pulses cultivated on strongly manured (dung-)soils and on cattle that were kept fenced on intensive pastures to easy collect the manure for pulse cultivation. The food web models indicate a low proportion of meat in human diet (approximately 10%). The largely crop-based diet, consisting of cereals plus up to 46% pulses, was balanced in calories and indispensable amino acids. The flourishing of Europe's first mega-populations depended on an advanced, integral mega-economy that included sophisticated dung management. Their demise was therefore not economically, but socially, conditioned [Hofmann et al., PLoS One. 14, e0222243 (2019)].


Assuntos
Agricultura , Isótopos , Animais , Humanos , Bovinos , Teorema de Bayes , Produtos Agrícolas , Produção Agrícola , Esterco/análise , Isótopos de Carbono/análise
6.
Am J Hum Genet ; 109(6): 1092-1104, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35568031

RESUMO

The spleen plays a key role in iron homeostasis. It is the largest filter of the blood and performs iron reuptake from old or damaged erythrocytes. Despite this role, spleen iron concentration has not been measured in a large, population-based cohort. In this study, we quantify spleen iron in 41,764 participants of the UK Biobank by using magnetic resonance imaging and provide a reference range for spleen iron in an unselected population. Through genome-wide association study, we identify associations between spleen iron and regulatory variation at two hereditary spherocytosis genes, ANK1 and SPTA1. Spherocytosis-causing coding mutations in these genes are associated with lower reticulocyte volume and increased reticulocyte percentage, while these common alleles are associated with increased expression of ANK1 and SPTA1 in blood and with larger reticulocyte volume and reduced reticulocyte percentage. As genetic modifiers, these common alleles may explain mild spherocytosis phenotypes that have been observed clinically. Our genetic study also identifies a signal that co-localizes with a splicing quantitative trait locus for MS4A7, and we show this gene is abundantly expressed in the spleen and in macrophages. The combination of deep learning and efficient image processing enables non-invasive measurement of spleen iron and, in turn, characterization of genetic factors related to the lytic phase of the erythrocyte life cycle and iron reuptake in the spleen.


Assuntos
Hemólise , Esferocitose Hereditária , Bancos de Espécimes Biológicos , Proteínas do Citoesqueleto/genética , Estudo de Associação Genômica Ampla , Homeostase/genética , Humanos , Ferro , Imageamento por Ressonância Magnética , Mutação , Esferocitose Hereditária/genética , Baço , Reino Unido
7.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35131897

RESUMO

Hydropower dams produce huge impacts on renewable energy production, water resources, and economic development, particularly in the Global South, where accelerated dam construction has made it a global hotspot. We do not fully understand the multiple impacts that dams have in the nearby areas from a global perspective, including the spatial differentiations. In this study, we examined the impacts of hydropower dam construction in nearby areas. We first found that more than one-third of global gross domestic production (GDP) and almost one-third of global population fall within 50 km of the world's 7,155 hydropower dams (<10% of the global land area sans the Antarctic). We further analyzed impacts of 631 hydropower dams (≥1-megawatt capacity) constructed since 2001 and commissioned before 2015 for their effects on economy, population, and environment in nearby areas and examined the results in five regions (i.e., Africa, Asia, Europe, North America, and South America) and by different dam sizes. We found that recently constructed dams were associated with increased GDP in North America and urban areas in Europe but with decreased GDP, urban land, and population in the Global South and greenness in Africa in nearby areas. Globally, these dams were linked with reduced economic production, population, and greenness of areas within 50 km of the dams. While large dams were related with reduced GDP and greenness significantly, small and medium dams were coupled with lowered population and urban land substantially, and large and medium dams were connected to diminished nighttime light noticeably in nearby areas.

8.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35042804

RESUMO

The 2016 Peace Agreement has increased access to Colombia's unique ecosystems, which remain understudied and increasingly under threat. The Colombian government has recently announced its National Bioeconomic Strategy (NBS), founded on the sustainable characterization, management, and conservation of the nation's biodiversity as a means to achieve sustainability and peace. Molecular tools will accelerate such endeavors, but capacity remains limited in Colombia. The Earth Biogenome Project's (EBP) objective is to characterize the genomes of all eukaryotic life on Earth through networks of partner institutions focused on sequencing either specific taxa or eukaryotic communities at regional or national scales. Colombia's immense biodiversity and emerging network of stakeholders have inspired the creation of the national partnership "EBP-Colombia." Here, we discuss how this Colombian-driven collaboration between government, academia, and the private sector is integrating research with sustainable, environmentally focused strategies to develop Colombia's postconflict bioeconomy and conserve biological and cultural diversity. EBP-Colombia will accelerate the uptake of technology and promote partnership and exchange of knowledge among Colombian stakeholders and the EBP's global network of experts; assist with conservation strategies to preserve Colombia's vast biological wealth; and promote innovative approaches among public and private institutions in sectors such as agriculture, tourism, recycling, and medicine. EBP-Colombia can thus support Colombia's NBS with the objective of sustainable and inclusive development to address the many social, environmental, and economic challenges, including conflict, inequality, poverty, and low agricultural productivity, and so, offer an alternative model for economic development that similarly placed countries can adopt.


Assuntos
Conservação dos Recursos Naturais/métodos , Genômica/métodos , Desenvolvimento Sustentável/tendências , Agricultura/métodos , Biodiversidade , Colômbia , Ecologia , Ecossistema , Genoma/genética , Programas Governamentais/tendências , Desenvolvimento Sustentável/economia
9.
Proc Natl Acad Sci U S A ; 119(11): e2105655119, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35254901

RESUMO

SignificanceMasting, or synchronous production of large seed crops, is widespread among plants. The predator satiation hypothesis states that masting evolved to overwhelm seed predators with an excess of food. Yet, this popular explanation faced few rigorous tests. We conducted a meta-analysis of studies that related the magnitude of seed production to the intensity of seed predation. Our results validate certain theoretical notions (e.g., that predator satiation is more effective at higher latitudes) but challenge others (e.g., that specialist and generalist consumers differ in the type of functional response to masting). We also found that masting is losing its ability to satiate consumers, probably because global warming affected masting patterns. This shift might considerably impair the reproduction of masting plants.


Assuntos
Modelos Teóricos , Plantas , Comportamento Predatório , Sementes , Animais
10.
Proc Natl Acad Sci U S A ; 119(51): e2206580119, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36525536

RESUMO

While the gig economy provides flexible jobs for millions of workers globally, a lack of organization identity and coworker bonds contributes to their low engagement and high attrition rates. To test the impact of virtual teams on worker productivity and retention, we conduct a field experiment with 27,790 drivers on a ride-sharing platform. We organize drivers into teams that are randomly assigned to receiving their team ranking, or individual ranking within their team, or individual performance information (control). We find that treated drivers work longer hours and generate significantly higher revenue. Furthermore, drivers in the team-ranking treatment continue to be more engaged 3 mo after the end of the experiment. A machine-learning analysis of 149 team contests in 86 cities suggests that social comparison, driver experience, and within-team similarity are the key predictors of the virtual team efficacy.

11.
Proc Natl Acad Sci U S A ; 119(47): e2208024119, 2022 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-36375060

RESUMO

For countries to rapidly decarbonize, they need strong leadership, according to both academic studies and popular accounts. But leadership is difficult to measure, and its importance is unclear. We use original data to investigate the role of presidents, prime ministers, and monarchs in 155 countries from 1990 to 2015 in changing their countries' gasoline taxes and subsidies. Our findings suggest that the impact of leaders on fossil fuel taxes and subsidies is surprisingly limited and often ephemeral. This holds true regardless of the leader's age, gender, education, or political ideology. Rulers who govern during an economic crisis perform no better or worse than other rulers. Even presidents and prime ministers who were recognized by the United Nations for environmental leadership had no more success than other leaders in reducing subsidies or raising fuel taxes. Where leaders appear to play an important role-primarily in countries with large subsidies-their reforms often failed, with subsidies returning to prereform levels within the first 12 mo 62% of the time, and within 5 y 87% of the time. Our findings suggest that leaders of all types find it exceptionally hard to raise the cost of fossil fuels for consumers. To promote deep decarbonization, leaders are likely to have more success with other types of policies, such as reducing the costs and increasing the availability of renewable energy.


Assuntos
Combustíveis Fósseis , Liderança , Impostos , Energia Renovável , Gasolina
12.
Proc Natl Acad Sci U S A ; 119(42): e2204073119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36215498

RESUMO

Sustainable circular economy requires materials that possess a property profile comparable to synthetic polymers and, additionally, processing and sourcing of raw materials that have a small environmental footprint. Here, we present a paradigm for processing marine biopolymers into materials that possess both elastic and plastic behavior within a single system involving a double-interpenetrating polymer network comprising the elastic phase of dynamic physical cross-links and stress-dissipating ionically cross-linked domains. As a proof of principle, films possessing more than twofold higher elastic modulus, ultimate tensile strength, and yield stress than those of polylactic acid were realized by blending two water-soluble marine polysaccharides, namely alginic acid (Alg) with physically cross-linkable carboxylated agarose (CA) followed by ionic cross-linking with a divalent cation. Dried CAAlg films showed homogeneous nano-micro-scale domains, with yield stress and size of the domains scaling inversely with calcium concentration. Through surface activation/cross-linking using calcium, CAAlg films could be further processed using wet bonding to yield laminated structures with interfacial failure loads (13.2 ± 0.81 N) similar to the ultimate loads of unlaminated films (10.09 ± 1.47 N). Toward the engineering of wood-marine biopolymer composites, an array of lines of CAAlg were printed on wood veneers (panels), dried, and then bonded following activation with calcium to yield fully bonded wood two-ply laminate. The system presented herein provides a blueprint for the adoption of marine algae-derived polysaccharides in the development of sustainable high-performance materials.


Assuntos
Ácido Algínico , Cálcio , Biopolímeros/química , Cátions Bivalentes , Plásticos , Polímeros/química , Polissacarídeos/química , Sefarose , Água/química
13.
J Physiol ; 602(7): 1297-1311, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38493355

RESUMO

The wide variation in muscle fibre type distribution across individuals, along with the very different energy consumption rates in slow versus fast muscle fibres, suggests that muscle fibre typology contributes to inter-individual differences in metabolic rate during exercise. However, this has been hard to demonstrate due to the gap between a single muscle fibre and full-body exercises. We investigated the isolated effect of triceps surae muscle contraction velocity on whole-body metabolic rate during cyclic contractions in individuals a priori selected for their predominantly slow (n = 11) or fast (n = 10) muscle fibre typology by means of proton magnetic resonance spectroscopy (1H-MRS). Subsequently, we examined their whole-body metabolic rate during walking and running at 2 m/s, exercises with comparable metabolic rates but distinct triceps surae muscle force and velocity demands (walking: low force, high velocity; running: high force, low velocity). Increasing triceps surae contraction velocity during cyclic contractions elevated net whole-body metabolic rate for both typology groups. However, the slow group consumed substantially less net metabolic energy at the slowest contraction velocity, but the metabolic difference between groups diminished at faster velocities. Consistent with the more economic force production during slow contractions, the slow group exhibited lower metabolic rates than the fast group while running, whereas metabolic rates were similar during walking. These findings provide important insights into the influence of muscle fibre typology on whole-body metabolic rate and emphasize the importance of considering muscle mechanical demands to understand muscle fibre typology related differences in whole-body metabolic rates. KEY POINTS: Muscle fibre typology is often suggested to affect whole-body metabolic rate, yet convincing in vivo evidence is lacking. Using isolated plantar flexor muscle contractions in individuals a priori selected for their predominantly slow or fast muscle fibre typology, we demonstrated that having predominantly slow muscle fibres provides a metabolic advantage during slow muscle contractions, but this benefit disappeared at faster contractions. We extended these results to full-body exercises, where we demonstrated that higher proportions of slow fibres associated with better economy during running but not when walking. These findings provide important insights into the influence of muscle fibre typology on whole-body metabolic rate and emphasize the importance of considering muscle mechanical demands to understand muscle fibre typology related differences in whole-body metabolic rate.


Assuntos
Contração Muscular , Corrida , Humanos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Fibras Musculares Esqueléticas , Perna (Membro) , Corrida/fisiologia
14.
Ecol Lett ; 27(3): e14402, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38511333

RESUMO

Plant species occupy distinct niches along a nitrogen-to-phosphorus (N:P) gradient, yet there is no general framework for belowground nutrient acquisition traits in relation to N or P limitation. We retrieved several belowground traits from databases, placed them in the "root economics space" framework, and linked these to a dataset of 991 plots in Eurasian herbaceous plant communities, containing plant species composition, aboveground community biomass and tissue N and P concentrations. Our results support that under increasing N:P ratio, belowground nutrient acquisition strategies shift from "fast" to "slow" and from "do-it-yourself" to "outsourcing", with alternative "do-it-yourself" to "outsourcing" strategies at both ends of the spectrum. Species' mycorrhizal capacity patterns conflicted with root economics space predictions based on root diameter, suggesting evolutionary development of alternative strategies under P limitation. Further insight into belowground strategies along nutrient stoichiometry is crucial for understanding the high abundance of threatened plant species under P limitation.


Assuntos
Micorrizas , Plantas , Biomassa , Nitrogênio , Nutrientes , Solo , Raízes de Plantas
15.
Ecol Lett ; 27(1): e14349, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38178545

RESUMO

The emergence of billions of periodical cicadas affects plant and animal communities profoundly, yet little is known about cicada impacts on soil carbon fluxes. We investigated the effects of Brood X cicadas (Magicicada septendecim, M. cassinii and M. septendeculain) on soil CO2 fluxes (RS ) in three Indiana forests. We hypothesized RS would be sensitive to emergence hole density, with the greatest effects occurring in soils with the lowest ambient fluxes. In support of our hypothesis, RS increased with increasing hole density and greater effects were observed near AM-associating trees (which expressed lower ambient fluxes) than near EcM-associating trees. Additionally, RS from emergence holes increased the temperature sensitivity (Q10 ) of RS by 13%, elevating the Q10 of ecosystem respiration. Brood X cicadas increased annual RS by ca. 2.5%, translating to an additional 717 Gg of CO2 across forested areas. As such, periodical cicadas can have substantial effects on soil processes and biogeochemistry.


Assuntos
Hemípteros , Micorrizas , Animais , Árvores , Ecossistema , Solo , Dióxido de Carbono , Florestas
16.
J Exp Bot ; 75(13): 3993-4004, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38634646

RESUMO

Hypoallometric (slope<1) scaling between metabolic rate and body mass is often regarded as near-universal across organisms. However, there are compelling reasons to question hypoallometric scaling in woody plants, where metabolic rate is directly proportional to leaf area. This leaf area must provide carbon to the volume of the metabolically active sapwood (VMASW). Within populations of a species, variants in which VMASW increases per unit leaf area with height growth (e.g. ⅔ or ¾ scaling) would have proportionally less carbon for growth and reproduction as they grow taller. Therefore, selection should favor individuals in which, as they grow taller, leaf area scales isometrically with shoot VMASW (slope=1). Using tetrazolium staining, we measured total VMASW and total leaf area (LAtot) across 22 individuals of Ricinus communis and confirmed that leaf area scales isometrically with VMASW, and that VMASW is much smaller than total sapwood volume. With the potential of the LAtot-VMASW relationship to shape factors as diverse as the crown area-stem diameter relationship, conduit diameter scaling, reproductive output, and drought-induced mortality, our work indicates that the notion that sapwood increases per unit leaf area with height growth requires revision.


Assuntos
Biomassa , Folhas de Planta , Árvores , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/anatomia & histologia , Árvores/crescimento & desenvolvimento , Árvores/metabolismo , Ricinus/crescimento & desenvolvimento , Ricinus/metabolismo , Madeira/crescimento & desenvolvimento , Madeira/metabolismo
17.
Chemistry ; 30(3): e202301919, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-37844012

RESUMO

Methylenedianiline (MDA) is a secondary, undesired, product of the glycolysis process of polyurethane (PU) scraps due to hydrolysis and pyrolysis side reactions. As an aromatic and carcinogen amine, MDA poses different problems in handling, transporting, and labelling recycled polyols derived from glycolysis, hindering the closure of PU recycling loop. Aiming to provide a solution to this issue, in this work different deaminating agents (DAs) were investigated with the purpose of analyzing their reactivity with MDA. A first part of the study was devoted to the analysis of MDA formation as a function of reaction time and catalyst concentration (potassium acetate) during glycolysis. It was observed that the amount of MDA increases almost linearly with the extent of PU depolymerization and catalyst content. Among the DAs analyzed 2-ethylhexyl glycidyl ether (2-EHGE), and acetic anhydride (Ac2 O) showed interesting performance, which allowed MDA content to be diminished below the limit for labelling prescription in 30 minutes. PU rigid foams were, therefore, synthesized from the corresponding recycled products and characterized in terms of thermal and mechanical performance. Ac2 O-deaminated polyols led to structurally unstable foams with poor compressive strength, while 2-EHGE-deaminated products allowed the production of foams with improved mechanical performance and unaltered thermal conductivity.

18.
Biotechnol Bioeng ; 121(2): 434-455, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37990982

RESUMO

Despite their high persistence in the environment, organochlorines (OC) are widely used in the pharmaceutical industry, in plastics, and in the manufacture of pesticides, among other applications. These compounds and the byproducts of their decomposition deserve attention and efficient proposals for their treatment. Among sustainable alternatives, the use of ligninolytic enzymes (LEs) from fungi stands out, as these molecules can catalyze the transformation of a wide range of pollutants. Among LEs, laccases (Lac) are known for their efficiency as biocatalysts in the conversion of organic pollutants. Their application in biotechnological processes is possible, but the enzymes are often unstable and difficult to recover after use, driving up costs. Immobilization of enzymes on a matrix (support or solid carrier) allows recovery and stabilization of this catalytic capacity. Agricultural residual biomass is a passive environmental asset. Although underestimated and still treated as an undesirable component, residual biomass can be used as a low-cost adsorbent and as a support for the immobilization of enzymes. In this review, the adsorption capacity and immobilization of fungal Lac on supports made from residual biomass, including compounds such as biochar, for the removal of OC compounds are analyzed and compared with the use of synthetic supports. A qualitative and quantitative comparison of the reported results was made. In this context, the use of peanut shells is highlighted in view of the increasing peanut production worldwide. The linkage of methods with circular economy approaches that can be applied in practice is discussed.


Assuntos
Basidiomycota , Poluentes Ambientais , Lacase , Biotecnologia , Biomassa , Fungos
19.
J Microsc ; 294(2): 75-83, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37742319

RESUMO

Towards the end of the 19th century and the early 20th century, France was the world's largest producer of antimony, especially due to the rich deposits in the Brioude-Massiac area. Even though all the mining and smelting activities are long gone, there are still some remains of those activities. The most original of those is the use of roasting slags as aggregates in former plant walls or industrial building. They are macroscopically characterised by a black or red colour with a vesicular aspect similar to natural pozzolanas. Common petrography and mineralogy tools have been used to characterise those slags: optical mineralogy, scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD). To gain an insight into their mineral complexity, a QEMSCAN map has been produced. The mineralogy is typical of high-temperature slags: cristobalite, quartz, mullite, fayalite-forsterite series and spinel. The antimony content is quite high, up to seven percent, under the form of various antimony oxides and native antimony.

20.
Am J Bot ; 111(5): e16347, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38760943

RESUMO

PREMISE: We assessed changes in traits associated with water economy across climatic gradients in the ecologically similar peat mosses Sphagnum cuspidatum and Sphagnum lindbergii. These species have parapatric distributions in Europe and have similar niches in bogs. Sphagnum species of bogs are closely related, with a large degree of microhabitat niche overlap between many species that can be functionally very similar. Despite this, ecologically similar species do have different distributional ranges along climatic gradients that partly overlap. These gradients may favor particular Sphagnum traits, especially in relation to water economy, which can be hypothesized to drive species divergence by character displacement. METHODS: We investigated traits relevant for water economy of two parapatric bryophytes (Sphagnum cuspidatum and S. lindbergii) across the border of their distributional limits. We included both shoot traits and canopy traits, i.e., collective traits of the moss surface, quantified by photogrammetry. RESULTS: The two species are ecologically similar and occur at similar positions along the hydrological gradient in bogs. The biggest differences between the species were expressed in the variations of their canopy surfaces, particularly surface roughness and in the responses of important traits such as capitulum mass to climate. We did not find support for character displacement, because traits were not more dissimilar in sympatric than in allopatric populations. CONCLUSIONS: Our results suggest that parapatry within Sphagnum can be understood from just a few climatic variables and that climatic factors are stronger drivers than competition behind trait variation within these species of Sphagnum.


Assuntos
Especificidade da Espécie , Sphagnopsida , Água , Sphagnopsida/fisiologia , Água/metabolismo , Clima , Ecossistema , Áreas Alagadas , Brotos de Planta/anatomia & histologia
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