In coastal regions and marginal bodies of water, the increase in partial pressure of carbon dioxide (
p
CO
2
) in many instances is greater than that of the open ocean due to terrestrial (river, ...estuarine, and wetland) influences, decreasing buffering capacity and/or increasing water temperatures. Coastal oceans receive freshwater from rivers and groundwater as well as terrestrial-derived organic matter, both of which have a direct influence on coastal carbonate chemistry. The objective of this research is to determine if coastal marshes in Georgia, USA, may be “hot-spots” for acidification due to enhanced inorganic carbon sources and if there is terrestrial influence on offshore acidification in the South Atlantic Bight (SAB). The results of this study show that dissolved inorganic carbon (DIC) and total alkalinity (TA) are elevated in the marshes compared to predictions from conservative mixing of the freshwater and oceanic end-members, with accompanying pH around 7.2 to 7.6 within the marshes and aragonite saturation states (Ω
Ar
) <1. In the marshes, there is a strong relationship between the terrestrial/estuarine-derived organic and inorganic carbon and acidification. Comparisons of pH, TA, and DIC to terrestrial organic material markers, however, show that there is little influence of terrestrial-derived organic matter on shelf acidification during this period in 2014. In addition, Ω
Ar
increases rapidly offshore, especially in drier months (July). River stream flow during 2014 was anomalously low compared to climatological means; therefore, offshore influences from terrestrial carbon could also be decreased. The SAB shelf may not be strongly influenced by terrestrial inputs to acidification during drier than normal periods; conversely, shelf waters that are well-buffered against acidification may not play a significant role in mitigating acidification within the Georgia marshes.
Biomass burning is an important primary source of particles containing biomarker compounds, which are introduced into smoke primarily by direct volatilization/steam stripping and by thermal ...alteration based on combustion conditions. This study presents comprehensive organic compound source profiles for smoke from controlled burning of green vegetation native to the predominant temperate and semiarid forests of the western United States. Smoke particles were extracted with dichloromethane/methanol (2:1, v/v), and the extracts were analyzed as their TMS derivatives by gas chromatography−mass spectrometry. Carbohydrates were by far the major compound class emitted in smoke particles, encompassing 57−77% of the total extractable organic compounds detected here. Lignin derivatives (5−17%) and diterpenoids (up to 16%) from bleed resins were the next most abundant compound groups observed. The major individual compounds encompassed methyl-inositols (up to 41%, e.g., pinitol) for conifer smokes, deoxy-inositols (up to 32%, e.g., quercitol) for samples containing oak vegetation, and the thermally altered product of cellulose combustion levoglucosan (14−21%). The remaining compound classes, i.e., n-alkanoic acids, n-alkanols, n-alkanes, triterpenoids, steroids, and polycyclic aromatic hydrocarbons, were present at lower abundances (mostly <5%). The results showed that burning of green (moist) vegetation imprints high amounts of polar/water-soluble compounds into the smoke probably by volatilization/steam stripping processes, resulting in a different biomarker profile compared to dry/dead vegetation and wood combustion emissions.
The composition of dissolved organic matter (DOM) in an estuary characterized by extensive salt marsh vegetation was investigated at the molecular level using ultrahigh‐resolution mass spectrometry ...and stable carbon isotope analyses. Samples from multiple seasons covered different hydrological regimes, including anomalously low‐discharge conditions. The untargeted approach used allowed for identifying the DOM molecular signatures associated with different DOM sources in the estuary. DOM composition was strongly modulated by river discharge at monthly scales, with high river flow leading to significant increases in the terrigenous signature of the DOM throughout the estuary. During a severe/exceptional drought, estuarine DOM was imprinted with a distinct signature of marsh‐derived compounds. The frequency of occurrence of anomalously low‐discharge conditions seems to have increased over the last decades. If predictions of anthropogenically driven changes in hydroclimate are confirmed, they will likely be accompanied by changes in DOM composition in estuaries at multidecadal time scales.
Key Points
DOM composition is modulated by variability in river discharge at monthly scales
Estuarine DOM imprinted with signature of marsh‐derived compounds during drought
Frequency of drought occurrence increased in the last decades
This study examined how people classify plants in terms of their taste and smell, and how those organoleptic properties influence the differential use of medicinal plants for treating different ...diseases.
We conducted an ethnobotanical survey of household heads in the community of Sucruiu, located in Barreiras, Bahia, Brazil. The head of each family was questioned concerning their knowledge and use of medicinal plants, as well as the therapeutic indications (TIs), taste, and smell of each plant. We then tested for associations between the therapeutic indications and taste attributes of various plants using the Chi-squared test on a contingency table with Monte Carlo simulations. The same analysis was performed for associations between TIs and smell.
The study participants provided more details when classifying tastes than when classifying smells. We considered only the most cited TIs and attributes, and found significant associations between both taste and therapeutic indications (p<0.001) and smell and therapeutic indications (p<0.0001).
Our results showed that the taste and smell of a plant can influence its differential medicinal use, since plants with certain tastes and smells prevailed in the treatment of distinct diseases. However, our results are valid only for the most popular TIs and organoleptic attributes.
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The present study aimed to understand human plant resource usage strategies in the context of the Ecological Apparency Hypothesis and Optimal Foraging Theory. The relationship between plant resource ...knowledge and availability was tested in a rural community (Palmital) in a dry Atlantic Forest fragment in the state of Minas Gerais, Southeastern Brazil, using data from phytosociological studies and interviews. We considered both total use and separate use categories. Use Value (UV) was significantly associated with all of the analyzed ecological variables, but there was an association with relative dominance and a weak relationship with relative density. When the UVs were separately analyzed for each category, we found that some, i.e., fuel and construction, corroborate the Ecological Apparency Hypothesis, while others do not, particularly the medicinal and food categories. In addition, we found large differences with respect to the ecological variables that best correlated with UV. The data suggest that the cost/benefit relationship predicted by Optimal Foraging Theory can explain the Ecological Apparency Hypothesis when the following factors are considered: (a) resource acquisition optimization and security; (b) a higher probability of acquiring more abundant species during random collection events; and (c) differential utilization patterns (distinct requirements for a specific use) for each use category. Some implications for conservation are also discussed.
Biochemical combinatorial techniques such as phage display, RNA display and oligonucleotide aptamers have proven to be reliable methods for generation of ligands to protein targets. Adapting these ...techniques to small synthetic molecules has been a long-sought goal. We report the synthesis and interrogation of an 800-million-member DNA-encoded library in which small molecules are covalently attached to an encoding oligonucleotide. The library was assembled by a combination of chemical and enzymatic synthesis, and interrogated by affinity selection. We describe methods for the selection and deconvolution of the chemical display library, and the discovery of inhibitors for two enzymes: Aurora A kinase and p38 MAP kinase.
Sponges are critical components of marine reefs due to their high filtering capacity, wide abundance, and alteration of biogeochemical cycling. Here, we characterized dissolved organic matter (DOM) ...composition in the sponge holobiont exhalent seawater of a loggerhead sponge (Spheciospongia vesparium) and in ambient seawater in Florida Bay (USA), as well as the microbial responses to each DOM pool through dark incubations. The sponge holobiont removed 6% of the seawater dissolved organic carbon (DOC), utilizing compounds that were low in carbon and oxygen, yet high in nitrogen content relative to the ambient seawater. The microbial community accessed 7% of DOC from the ambient seawater during a 5-day incubation but only 1% of DOC from the sponge exhalent seawater, suggesting a decrease in lability possibly due to holobiont removal of nitrogen-rich compounds. If this holds true for other sponges, it may have important implications for DOM lability and cycling in coastal environments.
•S. vesparium holobiont altered the DOM composition of seawater in Florida Bay.•Sponge-microbial holobiont uptook ~6% of DOC from ambient seawater.•Compounds with low carbon, low oxygen, and high nitrogen content were depleted.•Sponge exhalent water was enriched in large, more aromatic compounds.•Microbial consumption of DOC was higher in seawater than in sponge exhalent water.
There is little information available on the factors influencing people's selection of wild plants for consumption. Studies suggest a suitable method of understanding the selection of edible plants ...is to assess people's perceptions of these resources. The use and knowledge of wild resources is disappearing, as is the opportunity to use them. This study analyzes people's perceptions of native wild edible plants in a rural Caatinga (seasonal dry forest) community in Northeast Brazil and the relationships between the use of these resources and socioeconomic factors.
Semi-structured interviews with 39 people were conducted to form a convenience sample to gather information regarding people's perceptions of 12 native wild edible plant species. The relationships between variables were assessed by simple linear regression analysis, Pearson and Spearman correlation analyses, and in the case of nominal variables, contingency tables. The discourse of participants regarding their opinions of the use of wild plants as food was analyzed through the collective subject discourse analysis technique.
Perceptions were classified into 18 categories. The most cited category was organoleptic characteristics of the edible part; more specifically, flavor. Flavor was the main positive perception associated with plant use, whereas the negative perception that most limited the use of these plants was cultural acceptance. Perceptions of the use of wild edible plants were directly correlated with both interviewee age and income.
Within the studied community, people's perceptions of native wild edible plants are related to their consumption. Moreover, the study found that young people have less interest in these resources. These findings suggest that changing perceptions may affect the conservation of plants, traditional practices and the associated knowledge.
Extreme events such as hurricanes and tropical storms often result in large fluxes of dissolved organic carbon (DOC) to estuaries. Precipitation associated with tropical storms may be increasing in ...the southeastern U.S., which can potentially impact dissolved organic matter (DOM) dynamics and cycling in coastal systems. Here, DOM composition at the Altamaha River and Estuary (Georgia, U.S.A.) was investigated over multiple years capturing seasonal variations in river discharge, high precipitation events, and the passage of two hurricanes which resulted in substantial storm surges. Optical measurements of DOM indicate that the terrigenous signature in the estuary is linearly related to freshwater content and is similar after extreme events with or without a storm surge and during peak river flow. Molecular level analysis revealed significant differences, however, with a large increase of highly aromatic compounds after extreme events exceeding what would be expected by freshwater content alone. Although extreme events are often followed by increased DOC biodegradation, the terrigenous material added during those events does not appear to be more labile than the remainder of the DOM pool that was captured by ultrahigh-resolution mass spectrometry analysis. This suggests that the added terrigenous organic matter may be exported to the coastal ocean, while a fraction of the organic matter that co-varied with the terrigenous DOM may contribute to the increased biomineralization in the estuary, with implications to carbon processing in coastal areas.
This study describes the biochemical and functional characterization of a new metalloproteinase named BbMP-1, isolated from Bothrops brazili venom. BbMP-1 was homogeneous on SDS-PAGE, presented ...molecular mass of 22,933Da and pI 6.4. The primary structure was partially elucidated with high identity with others metalloproteinases from Viperidae venoms. The enzymatic activity on azocasein was evaluated in different experimental conditions (pH, temperature). A significant reduction in enzyme activity after exposure to chelators of divalent cations (EDTA), reducing agents (DTT), pH less than 5.0 or temperatures higher than 45 °C was observed. BbMP-1 showed activity on fibrinogen degrading Aα chain quickly and to a lesser extent the Bβ chain. Also demostrated to be weakly hemorrhagic, presenting however, significant myotoxic and edematogenic activity. The in vitro activity of BbMP-1 against Plasmodium falciparum showed an IC50 of 3.2 ± 2.0 μg/mL. This study may help to understand the pathophysiological effects induced by this group of toxin and their participation in the symptoms observed in cases of snake envenomation. Moreover, this result is representative for this group of proteins and shows the biotechnological potential of BbMP-1 by the demonstration of its antiplasmodial activity.
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•Biochemical and functional characterization of a new metalloproteinase.•BbMP-1 isolated from Bothrops brazili snake venom.•The in vitro activity of BbMP-1 against Plasmodium falciparum.
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