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1.
PLoS One ; 19(4): e0301392, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38578719

RESUMO

Despite is known to have widespread distribution and the most active species of the family Chlorocyphidae, the molecular data of Rhinocypha fenestrella (Rambur, 1842) are relatively scarce. The present study is the first that examined the genetic diversity and phylogeographic pattern of the peacock jewel-damselfly R. fenestrella by sequencing the cytochrome C oxidase I (cox1) and 16S rRNA gene regions from 147 individuals representing eight populations in Malaysia. A total of 26 and 10 unique haplotypes were revealed by the cox1 and 16S rRNA genes, respectively, and 32 haplotypes were recovered by the concatenated sequences of cox1+16S. Analyses indicated that haplotype AB2 was the most frequent and the most widespread haplotype in Malaysia while haplotype AB1 was suggested as the common ancestor haplotype of the R. fenestrella that may arose from the Negeri Sembilan as discovered from cox1+16S haplotype network analysis. Overall haplotype and nucleotide diversities of the concatenated sequences were Hd = 0.8937 and Pi = 0.0028, respectively, with great genetic differentiation (FST = 0.6387) and low gene flow (Nm = 0.14). Population from Pahang presented the highest genetic diversity (Hd = 0.8889, Pi = 0.0022, Nh = 9), whereas Kedah population demonstrated the lowest diversity (Hd = 0.2842, Pi = 0.0003, Nh = 4). The concatenated sequences of cox1+16S showed genetic divergence ranging from 0.09% to 0.97%, whereas the genetic divergence for cox1 and 16S rRNA genes were 0.16% to 1.63% and 0.01% to 0.75% respectively. This study provides for the first-time insights on the intraspecific genetic diversity, phylogeographic pattern and ancestral haplotype of Rhinocypha fenestrella. The understanding of molecular data especially phylogeographic pattern can enhance the knowledge about insect origin, their diversity, and capability to disperse in particular environments.


Assuntos
Variação Genética , Odonatos , Humanos , Animais , Filogenia , RNA Ribossômico 16S/genética , Odonatos/genética , Filogeografia , Haplótipos , DNA Mitocondrial/genética
2.
J Mol Graph Model ; 129: 108757, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38503002

RESUMO

The determination of the critical micelle concentration (CMC) is a crucial factor when evaluating surfactants, making it an essential tool in studying the properties of surfactants in various industrial fields. In this present research, we assembled a comprehensive set of 593 different classes of surfactants including, anionic, cationic, nonionic, zwitterionic, and Gemini surfactants to establish a link between their molecular structure and the negative logarithmic value of critical micelle concentration (pCMC) utilizing quantitative structure-property relationship (QSPR) methodologies. Statistical analysis revealed that a set of 14 significant Mordred descriptors (SlogP, GATS6d, nAcid, GATS8dv, GATS4dv, PEOE_VSA11, GATS8d, ATS0p, GATS1d, MATS5p, GATS3d, NdssC, GATS6dv and EState_VSA4), along with temperature, served as appropriate inputs. Different machine learning methods, such as multiple linear regression (MLR), random forest regression (RFR), artificial neural network (ANN), and support vector regression (SVM), were employed in this study to build QSPR models. According to the statistical coefficients of QSPR models, SVR with Dragonfly hyperparameter optimization (SVR-DA) was the most accurate in predicting pCMC values, achieving (R2 = 0.9740, Q2 = 0.9739, r‾m2 = 0.9627, and Δrm2 = 0.0244) for the entire dataset.


Assuntos
Micelas , Odonatos , Animais , Tensoativos/química , Algoritmos , Relação Quantitativa Estrutura-Atividade , Aprendizado de Máquina
3.
Int J Med Mushrooms ; 26(3): 41-53, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38505902

RESUMO

The worldwide scientific community is well aware that mosquitoes are the sole agents responsible for transmitting various dreadful diseases and critical illnesses caused by vector-borne pathogens. The primary objective of this current research was to evaluate the effectiveness of methanol extract from Tricholoma equestre mushroom in controlling the early life stages of Culex quinquefasciatus Say, Anopheles stephensi Liston, and Aedes aegypti (Linnaeus in Hasselquist) mosquitoes. The larvae, pupae and eggs of these mosquitoes were exposed to four different concentrations (62.5 to 500 ppm). After 120 h of treatment, the methanol extract of T. equestre exhibited ovicidal activity ranging from 66% to 80% against the eggs of the treated mosquitoes. It also demonstrated promising larvicidal and pupicidal activity with LC50 values of 216-300 and 230-309 ppm against the early life stages of all three mosquito species. Extensive toxicity studies revealed that the methanol extract from T. equestre had no harmful effects on non-target organisms. The suitability index (SI) or predator safety factor (PSF) indicated that the methanol extract did not harm Poecilia reticulata Peters 1859, (predatory fish), Gambusia affinis S. F. Baird & Girard 1853, dragonfly nymph and Diplonychus indicus Venkatesan & Rao 1871 (water-bug). Gas chromatography-mass spectrometry (GCMS) analysis identified key compounds, including 3-butenenitrile, 2-methyl-(25.319%); 1-butanol, 2-nitro-(18.87%) and oxalic acid, heptyl propyl ester (21.82%) which may be responsible for the observed activity. Furthermore, the formulation based on the methanol extract demonstrated similar effectiveness against all treated mosquitoes at the laboratory level and was found to be non-toxic to mosquito predators. This groundbreaking research represents the first confirmation that methanol extract from T. equestre could be effectively employed in preventing mosquito-borne diseases through mosquito population control programs.


Assuntos
Aedes , Agaricales , Anopheles , Culex , Inseticidas , Odonatos , Animais , Metanol/farmacologia , Mosquitos Vetores , Inseticidas/farmacologia , Inseticidas/química , Extratos Vegetais/química , Larva , Folhas de Planta/química
4.
Zootaxa ; 5415(4): 529-542, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38480185

RESUMO

The final stadium larva of Anisopleura furcata Selys, 1891 is described and illustrated. The larva can be separated from all known Anisopleura Selys, 1853 larvae by the following characters: the profusion of elongated tubercles on the labrum and antefrons, the presence of a long bifid spur on the outer margin of the mandibles, presence of a row of claviform setae on dorsal apex of tarsus, and antennae 8-segmented. The inner lobe of the labial palps forms a tiny truncate tooth broadly similar to the condition in all other known members of the genus. Diagnostic features that separate this species from potentially syntopic euphaeid genera are discussed.


Assuntos
Odonatos , Animais , Larva , Tailândia
5.
Zootaxa ; 5415(3): 493-498, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38480188

RESUMO

We describe the new genus and species Stolleagrion foghnielseni n. gen. et sp. from the Fur Formation in northwestern Denmark based on a single fossil wing. This is the first odonatan described from the earliest part of the PETM recovery phase of the early Eocene. A combination of nine wing character states are considered to be diagnostic of the Dysagrionidae Cockrell only together with the cephalozygopteran head; however, the combination of these nine plus the presence of Ax0 is also diagnostic without the head. By this, we assign Stolleagrion foghnielseni to the Dysagrionidae and reassess the position of other odonates previously treated as cf. Dysagrionidae.


Assuntos
Odonatos , Animais , Fósseis , Asas de Animais
6.
Zootaxa ; 5415(2): 201-240, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38480206

RESUMO

The cosmopolitan family Lestidae Calvert, 1901 has two widely distributed genera in the Americas: Archilestes Selys, 1862, and Lestes Leach, 1815. In Colombia, this family is represented by 11 species. In this study, we present a diagnosis of Lestidae species in Colombia based on a thorough review of the countrys main entomological collections. A total of 258 specimens representing ten species were examined. The species L. dichrostigma Calvert, 1909, is recorded for the first time. The presence of L. henshawi Calvert, 1907 is excluded, and the taxonomic status of L. sternalis (Navs, 1930) is discussed. Finally, we present distribution maps, photographs of Lestidae species, taxonomical important structures, and taxonomic keys for both males and females.


Assuntos
Odonatos , Feminino , Masculino , Animais , Colômbia
7.
Zootaxa ; 5410(1): 1-48, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38480259

RESUMO

As of August 2023, 220 species in 57 genera and 10 families of damselflies and dragonflies (Insecta: Odonata) are recorded for Canada. Since the publication of the first edition in 2005, 14 species have been added to the list; one,Neurocordulia obsoleta (Say) has been removed because of a misidentification and another, Sympetrum occidentale, has been to synonymy. Conservation ranks are given for species in all 13 provinces and territories. English and French names for all listed species are included. Literature sources are discussed and presented, as is information on species status and the addition and exclusion of species. Sections on taxonomy and variation, subspecies, presumed hybrids, the introduction of exotic species, notable range extensions and observations, and conservation and protection are also provided.


Assuntos
Odonatos , Animais , Insetos , Canadá
8.
Zootaxa ; 5424(2): 243-250, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38480285

RESUMO

The female of Leptagrion jeromei Lencioni, Vilela & Furieri, 2021 is described, illustrated, and diagnosed based on a specimen collected in epiphytic bromeliads at the Federal University of Sergipe ( (B0545), BRAZIL, Federal University of Sergipe, So Cristvo, -10.92707, -37.10100, 30 m asl, 6.x.2023, A.B.S. Farias & J.C. Santos leg.). Additionally, we provide information on its biology, ecology, and taxonomic notes, along with illustrations of the collected males.


Assuntos
Odonatos , Feminino , Masculino , Animais
9.
Zootaxa ; 5405(1): 1-42, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38480398

RESUMO

We provide updated synonymies for various genera and species of Neotropical Zygoptera based on examination of specimens and literature accompanied by justifications and supported by illustrations. The following generic synonyms are proposed: Austrotepuibasis Machado & Lencioni, 2011 and Pseudotepuibasis Stand-Prez & Prez-Gutirrez, 2020 are junior synonyms of Tepuibasis De Marmels, 2007; Fredyagrion Lencioni, 2022, Kiautagrion Lencioni, 2022, Nathaliagrion Lencioni, 2022, and Machadagrion Lencioni, 2022 are junior synonyms of Leptagrion Selys, 1876; Juenagrion Lencioni, 2023 is a junior synonym of Telebasis Selys, 1865. The following specific synonyms are proposed: Lestes fernandoi Costa, Souza & Muzn, 2006 is a junior synonym of Lestes debellardi De Marmels, 1992; Lestes tikalus Kormondy, 1959 is a junior synonym of Lestes scalaris Gundlach, 1888; Palaemnema brasiliensis Machado, 2009 is a junior synonym of Palaemnema brevignoni Machet, 1990; Hetaerina aurora Ris, 1918 is a junior synonym of Hetaerina duplex Selys, 1853; Hetaerina hebe Selys, 1853 is a junior synonym of Hetaerina longipes Hagen in Selys, 1853; Mnesarete mariana Machado, 1996 is a junior synonym of Mnesarete guttifera (Selys, 1873); Acanthagrion hartei Muzn & Lozano, 2005 is a junior synonym of Acanthagrion obsoletum (Frster, 1914); Oxyagrion bruchi Navs, 1924 is a junior synonym of Oxyagrion ablutum (Calvert, 1909); Austrotepuibasis alvarengai Machado & Lencioni, 2011 and Austrotepuibasis manolisi Machado & Lencioni, 2011 are junior synonyms of Tepuibasis demarmelsi (Machado & Lencioni, 2011). Helveciagrion Machado, 1980 is again considered a junior synonym of Telebasis Selys, 1865; Leptagrion auriceps St. Quentin, 1960 is again considered a junior synonym of Leptagrion macrurum (Burmeister, 1839), and Homeoura sobrina (Schmidt, 1943) is transferred back to Ischnura Charpentier. The following synonymies are tentatively proposed pending further examination of specimens: Philogenia lankesteri Calvert, 1924 is a possible junior synonym of Philogenia carrillica Calvert, 1907; Leptagrion jeromei Lencioni, Vilela & Furieri in Vilela, Garcia Jnior, Furieri & Lencioni, 2021 is a possible junior synonym of Leptagrion andromache Hagen in Selys, 1876; Phoenicagrion flavescens Machado, 2010 is a possible junior synonym of Phoenicagrion flammeum (Selys, 1876); Tuberculobasis mammilaris (Calvert, 1909) is a possible junior synonym of Tuberculobasis croceum (Burmeister, 1839) new combination. The status of Agrion rufovittatum Blanchard, 1846 is briefly discussed.


Assuntos
Odonatos , Animais
10.
Zootaxa ; 5403(5): 587-591, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38480415

RESUMO

Oxyagrion franciscoi Machado & Bede, 2016 is a critically endangered damselfly species endemic to the Serra da Canastra National Park, Brazil, a vital environmental reserve within the Cerrado hotspot for biodiversity conservation. Here we reared, illustrated, and described the last instar larva of O. franciscoi.


Assuntos
Odonatos , Animais , Parques Recreativos , Larva , Biodiversidade , Poaceae
11.
Zootaxa ; 5403(3): 320-330, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38480436

RESUMO

The new species, Calesynthemis jeanlegrandi sp. nov., dedicated to the late Jean Legrand, is described and illustrated based on a single pair of specimens from Mont Pani, New Caledonia. The male of this large species has unusual strongly sinuous and distally down curved white cerci 7 mm long and exhibits on abdominal segment 10 a remarkable clump of strong setae mimicking a dorsal horn. The female wingspan slightly exceeds 100 mm. In addition, on the basis of adult and larval characters, Neocaledosynthemis gen. nov. is erected to accommodate two other New Caledonian synthemistids, Synthemis fenella Campion (type species) and Synthemis ariadne Lieftinck. New Caledonian synthemistids are probably more closely related to Parasynthemis Carle than to Synthemis Selys Longchamps, both from Australia.


Assuntos
Dipterocarpaceae , Odonatos , Masculino , Feminino , Animais , Nova Caledônia , Filogenia , Larva
12.
ACS Nano ; 18(13): 9451-9469, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38452378

RESUMO

The production of wood-based panels has a significant demand for mechanically strong and flexible biomass adhesives, serving as alternatives to nonrenewable and toxic formaldehyde-based adhesives. Nonetheless, plywood usually exhibits brittle fracture due to the inherent trade-off between rigidity and toughness, and it is susceptible to damage and deformation defects in production applications. Herein, inspired by the microstructure of dragonfly wings and the cross-linking structure of plant cell walls, a soybean meal (SM) adhesive with great strength and toughness was developed. The strategy was combined with a multiple assembly system based on the tannic acid (TA) stripping/modification of molybdenum disulfide (MoS2@TA) hybrids, phenylboronic acid/quaternary ammonium doubly functionalized chitosan (QCP), and SM. Motivated by the microstructure of dragonfly wings, MoS2@TA was tightly bonded with the SM framework through Schiff base and strong hydrogen bonding to dissipate stress energy through crack deflection, bridging, and immobilization. QCP imitated borate chemistry in plant cell walls to optimize interfacial interactions within the adhesive by borate ester bonds, boron-nitrogen coordination bonds, and electrostatic interactions and dissipate energy through sacrificial bonding. The shear strength and fracture toughness of the SM/QCP/MoS2@TA adhesive were 1.58 MPa and 0.87 J, respectively, which were 409.7% and 866.7% higher than those of the pure SM adhesive. In addition, MoS2@TA and QCP gave the adhesive good mildew resistance, durability, weatherability, and fire resistance. This bioinspired design strategy offers a viable and sustainable approach for creating multifunctional strong and tough biobased materials.


Assuntos
Odonatos , Polifenóis , Animais , Molibdênio , Boratos , Parede Celular , Soja , Adesivos
13.
BMC Ecol Evol ; 24(1): 19, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38308224

RESUMO

BACKGROUND: Describing geographical variation in morphology of organisms in combination with data on genetic differentiation and biogeography can provide important information on how natural selection shapes such variation. Here we study genetic structure using ddRAD seq and wing shape variation using geometric morphometrics in 14 populations of the damselfly Lestes sponsa along its latitudinal range in Europe. RESULTS: The genetic analysis showed a significant, yet relatively weak population structure with high genetic heterozygosity and low inbreeding coefficients, indicating that neutral processes contributed very little to the observed wing shape differences. The genetic analysis also showed that some regions of the genome (about 10%) are putatively shaped by selection. The phylogenetic analysis showed that the Spanish and French populations were the ancestral ones with northern Swedish and Finnish populations being the most derived ones. We found that wing shape differed significantly among populations and showed a significant quadratic (but weak) relationship with latitude. This latitudinal relationship was largely attributed to allometric effects of wing size, but non-allometric variation also explained a portion of this relationship. However, wing shape showed no phylogenetic signal suggesting that lineage-specific variation did not contribute to the variation along the latitudinal gradient. In contrast, wing size, which is correlated with body size in L. sponsa, had a strong negative correlation with latitude. CONCLUSION: Our results suggest a relatively weak population structure among the sampled populations across Europe, but a clear differentiation between south and north populations. The observed geographic phenotypic variation in wing shape may have been affected by different local selection pressures or environmental effects.


Assuntos
Odonatos , Animais , Filogeografia , Filogenia , Odonatos/genética , Europa (Continente) , Variação Biológica da População
14.
Am Nat ; 203(3): 335-346, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38358816

RESUMO

AbstractInterference competition can drive species apart in habitat use through competitive displacement in ecological time and agonistic character displacement (ACD) over evolutionary time. As predicted by ACD theory, sympatric species of rubyspot damselflies (Hetaerina spp.) that respond more aggressively to each other in staged encounters differ more in microhabitat use. However, the same pattern could arise from competitive displacement if dominant species actively exclude subordinate species from preferred microhabitats. The degree to which habitat partitioning is caused by competitive displacement can be assessed with removal experiments. We carried out removal experiments with three species pairs of rubyspot damselflies. With competitive displacement, removing dominant species should allow subordinate species to shift into the dominant species' microhabitat. Instead, we found that species-specific microhabitat use persisted after the experimental removals. Thus, the previously documented association between heterospecific aggression and microhabitat partitioning in this genus is most likely a product of divergence in habitat preferences caused by interference competition in the evolutionary past.


Assuntos
Evolução Biológica , Odonatos , Animais , Agressão , Simpatria
15.
Proc Natl Acad Sci U S A ; 121(10): e2313371121, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38408245

RESUMO

One of the drivers of life's diversification has been the emergence of "evolutionary innovations": The evolution of traits that grant access to underused ecological niches. Since ecological interactions can occur separately from mating, mating-related traits have not traditionally been considered factors in niche evolution. However, in order to persist in their environment, animals need to successfully mate just as much as they need to survive. Innovations that facilitate mating activity may therefore be an overlooked determinant of species' ecological limits. Here, we show that species' historical niches and responses to contemporary climate change are shaped by an innovation involved in mating-a waxy, ultra-violet-reflective pruinescence produced by male dragonflies. Physiological experiments in two species demonstrate that pruinescence reduces heating and water loss. Phylogenetic analyses show that pruinescence is gained after taxa begin adopting a thermohydrically stressful mating behavior. Further comparative analyses reveal that pruinose species are more likely to breed in exposed, open-canopy microhabitats. Biogeographic analyses uncover that pruinose species occupy warmer and drier regions in North America. Citizen-science observations of Pachydiplax longipennis suggest that the extent of pruinescence can be optimized to match the local conditions. Finally, temporal analyses indicate that pruinose species have been buffered against contemporary climate change. Overall, these historical and contemporary patterns show that successful mating can shape species' niche limits in the same way as growth and survival.


Assuntos
Mudança Climática , Odonatos , Animais , Masculino , Filogenia , Ecossistema , Reprodução , Evolução Biológica
16.
Exp Parasitol ; 258: 108709, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301765

RESUMO

Mosquitoes stand out as the most perilous and impactful vectors on a global scale, transmitting a multitude of infectious diseases to both humans and other animals. The primary objective of the current research was to assess the effectiveness of EOs from Ocimum tenuiflorum L. and Ocimum americanum L. in controlling Anopheles stephensi Liston. Culex quinquefasciatus Say and Aedes aegypti L. mosquitoes. The larvae, pupae and eggs of the mosquitoes were exposed to four different concentrations (6.25-50 ppm). The tested EOs resulted in >99-100 % mortality at 120 h for the eggs of all examined mosquito species. It also showed robust larvicidal and pupicidal activity with LC50 and LC90 values of 17-39, 23-60 ppm and 46-220, and 73-412 ppm against Aedes, Culex and Anopheles mosquito species, respectively, at 24 h of treatment. The Suitability Index or Predator Safety Factor demonstrated that the EOs extracted from O. tenuiflorum L. and O. americanum L. did not cause harm to P. reticulata, D. indicus (water bug), G. affinis and nymph (dragonfly). GC-MS analysis identified the major probable constituents of the oil, including Phenol, 2-Methoxy-4-(1-Propenyl)- (28.29 %); 1-Methyl-3-(1'-Methylcyclopropyl) Cyclopentene (46.46 %); (E,E,E)-3,7,11,15-Tetramethylhexadeca-1,3,6,10,14-Pentaene (18.91 %) and 1,3-Isobenzofurandione, 3a,4,7,7a-Tetrahydro-4,7-Dimethyl (33.02 %). These constituents may play a significant role in the mosquitocidal activity of the oil. The same results were identified in the formulation prepared from the EOs. This marks the first report confirming the successful utilization of EOs derived from O. tenuiflorum L. and O. americanum L. in mosquito population control initiatives.


Assuntos
Aedes , Anopheles , Culex , Inseticidas , Ocimum , Odonatos , Óleos Voláteis , Animais , Humanos , Óleos Voláteis/farmacologia , Óleos Voláteis/análise , Ocimum/química , Ocimum sanctum , Mosquitos Vetores , Inseticidas/análise , Larva , Extratos Vegetais/química , Folhas de Planta/química
17.
PLoS One ; 19(2): e0295707, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38394143

RESUMO

Global warming and invasive species, separately or combined, can impose a large impact on the condition of native species. However, we know relatively little about how these two factors, individually and in combination, shape phenotypes in ectotherms across life stages and how this can differ between populations. We investigated the non-consumptive predator effects (NCEs) imposed by native (perch) and invasive (signal crayfish) predators experienced only during the egg stage or during both the egg and larval stages in combination with warming on adult life history traits of the damselfly Ischnura elegans. To explore microgeographic differentiation, we compared two nearby populations differing in thermal conditions and predator history. In the absence of predator cues, warming positively affected damselfly survival, possibly because the warmer temperature was closer to the optimal temperature. In the presence of predator cues, warming decreased survival, indicating a synergistic effect of these two variables on survival. In one population, predator cues from perch led to increased survival, especially under the current temperature, likely because of predator stress acclimation phenomena. While warming decreased, predator cues increased larval development time with a proportionally stronger effect of signal crayfish cues experienced during the egg stage, indicating a negative carry-over effect from egg to larva. Warming and predator cues increased mass at emergence, with the predator effect driven mainly by exposure to signal crayfish cues during the egg stage, indicating a positive carry-over effect from egg to adult. Notably, warming and predator effects were not consistent across the two studied populations, suggesting a phenotypic signal of adaptation at a microgeographic scale to thermal conditions and predator history. We also observed pronounced shifts during ontogeny from synergistic (egg and early larval stage) toward additive (late larval stage up to emergence) effects between warming and predator stress. The results point out that population- and life-stage-specific responses in life-history traits to NCEs are needed to predict fitness consequences of exposure to native and invasive predators and warming in prey at a microgeographic scale.


Assuntos
Odonatos , Animais , Odonatos/fisiologia , Larva/fisiologia , Temperatura , Comportamento Predatório/fisiologia
18.
J Hazard Mater ; 468: 133783, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38367440

RESUMO

To elucidate the sources and transfer of mercury (Hg) in terrestrial food chains, particularly in heavily Hg-contaminated rice paddy ecosystems, we collected rice leaves, invertebrates, and Russet Sparrow nestlings from a clear food chain and analyzed the dietary compositions and potential Hg sources using stable Hg isotopes coupled with a Bayesian isotope mixing model (BIMM). Our findings indicated that MeHg exposure is dominant through the dietary route, with caterpillars, grasshoppers, and katydids being the main prey items, while the less provisioned spiders, dragonflies, and mantises contributed the most of the Hg to nestlings. We found minimal MIF but certain MDF in this terrestrial food chain and identified two distinct MeHg sources of dietary exposure and maternal transfer. We firstly found that the dietary route contributed substantially (almost tenfold) more MeHg to the nestlings than maternal transfer. These findings offer new insights into the integration of Hg from the dietary route and maternal transfers, enhancing our understanding of fluctuating Hg exposure risk during the nestling stage. Our study suggested that Hg isotopes combined with BIMM is an effective approach for tracing Hg sources in birds and for gaining in-depth insight into the trophic transfers and biomagnification of MeHg in food chains.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Odonatos , Oryza , Aves Canoras , Poluentes Químicos da Água , Animais , Isótopos de Mercúrio/análise , Cadeia Alimentar , Ecossistema , Bioacumulação , Teorema de Bayes , Mercúrio/análise , Isótopos , Monitoramento Ambiental , Poluentes Químicos da Água/análise
19.
Chirality ; 36(3): e23655, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38419363

RESUMO

This study reports the microscopic measurements of vibrational circular dichroism (VCD) on four different insect wings using a quantum cascade laser VCD system equipped with microscopic scanning capabilities (named multi-dimensional VCD [MultiD-VCD]). Wing samples, including (i) beetle, Anomala albopilosa (female), (ii) European hornet, Verspa crabro flavofasciata Cameron, 1903 (female), (iii) tiny dragonfly, Nannophya pygmae Rambur, 1842 (male), and (iv) dragonfly, Symetrum gracile Oguma, 1915 (male), were used in this study. Two-dimensional patterns of VCD signals (~10 mm × 10 mm) were obtained at a spatial resolution of 100 µm. Measurements covered the absorption peaks assigned to amides I and II in the range of 1500-1740 cm-1 . The measurements were based on the enhancement of VCD signals for the stereoregular linkage of peptide groups. The patterns were remarkably dependent on the species. In samples (i) and (ii), the wings comprised segregated domains of protein aggregates of different secondary structures. The size of each microdomain was approximately 100 µm. In contrast, no clear VCD spectra were detected in samples (iii) and (iv). One possible reason was that the chain of stereoregular polypeptides was too short to achieve VCD enhancement in samples (iii) and (iv). Notably, the unique features were only observed in the VCD spectra because the IR spectra were nearly the same among the species. The VCD results hinted at the connection of protein microscopic structures with the wing flapping mechanisms of each species.


Assuntos
Odonatos , Feminino , Masculino , Animais , Dicroísmo Circular , Estereoisomerismo , Peptídeos/química , Proteínas
20.
Environ Monit Assess ; 196(3): 281, 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38368304

RESUMO

The evaluation of environmental and spatial influence in freshwater systems is crucial for the conservation of aquatic diversity. So, we evaluated communities of Odonata in streams inside and outside sustainable use areas in the Brazilian western Amazon. We predicted that these streams would differ regarding habitat integrity and species α and ß diversity. We also predict that environmental and spatial variables will be important for both suborders, but with more substantial effects on Zygoptera species, considering their nature of forest-specialist. The study was conducted in 35 streams, 19 inside and 16 outside sustainable use areas. The streams outside presented high species richness, abundance, and number of exclusive forest-specialist species from Zygoptera and higher scores of habitat integrity. In contrast, one sustainable use area presented the lowest values of these metrics. Besides, we found that environmental and spatial variables were significantly associated to Zygoptera species composition, but not with Anisoptera, which can be explained by their cosmopolitan nature. Our results indicated that an interplay between environmental and spatial processes determines the structure of the metacommunities of Zygoptera. The less effective dispersal rates and narrow ecological tolerance of Zygoptera species make them more influenced by local conditions and dispersal limitation, and more sensible to habitat modifications. We highlight the importance of improving the local management of the sustainable use areas by environmental agencies, mainly on areas that are losing their capacity to maintain the aquatic fauna, and implementation of social policies toward traditional people.


Assuntos
Odonatos , Humanos , Animais , Rios , Brasil , Monitoramento Ambiental , Ecossistema , Insetos , Biodiversidade
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