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1.
Front Physiol ; 15: 1352766, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725570

RESUMO

Autophagy is a cellular degradation pathway mediated by highly conserved autophagy-related genes (Atgs). In our previous work, we showed that inhibiting autophagy under starvation conditions leads to significant physiological changes in the insect vector of Chagas disease Rhodnius prolixus; these changes include triacylglycerol (TAG) retention in the fat body, reduced survival and impaired locomotion and flight capabilities. Herein, because it is known that autophagy can be modulated in response to various stimuli, we further investigated the role of autophagy in the fed state, following blood feeding. Interestingly, the primary indicator for the presence of autophagosomes, the lipidated form of Atg8 (Atg8-II), displayed 20%-50% higher autophagic activation in the first 2 weeks after feeding compared to the third week when digestion was complete. Despite the elevated detection of autophagosomes, RNAi-mediated suppression of RpAtg6 and RpAtg8 did not cause substantial changes in TAG or protein levels in the fat body or the flight muscle during blood digestion. We also found that knockdown of RpAtg6 and RpAtg8 led to modest modulations in the gene expression of essential enzymes involved in lipid metabolism and did not significantly stimulate the expression of the chaperones BiP and PDI, which are the main effectors of the unfolded protein response. These findings indicate that impaired autophagy leads to slight disturbances in lipid metabolism and general cell proteostasis. However, the ability of insects to fly during forced flight until exhaustion was reduced by 60% after knockdown of RpAtg6 and RpAtg8. This change was accompanied by TAG and protein increases as well as decreased ATP levels in the fat body and flight muscle, indicating that autophagy during digestion, i.e., under fed conditions, is necessary to sustain high-performance activity.

2.
Mol Microbiol ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720451

RESUMO

Aedes aegypti females are natural vectors of important arboviruses such as dengue, zika, and yellow fever. Mosquitoes activate innate immune response signaling pathways upon infection, as a resistance mechanism to fight pathogens and limit their propagation. Despite the beneficial effects of immune activation for insect vectors, phenotypic costs ultimately affect their fitness. However, the underlying mechanisms that mediate these fitness costs remain poorly understood. Given the high energy required to mount a proper immune response, we hypothesized that systemic activation of innate immunity would impair flight muscle mitochondrial function, compromising tissue energy demand and flight activity. Here, we investigated the dynamic effects of activation of innate immunity by intra-thoracic zymosan injection on A. aegypti flight muscle mitochondrial metabolism. Zymosan injection significantly increased defensin A expression in fat bodies in a time-dependent manner that compromised flight activity. Although oxidant levels in flight muscle were hardly altered, ATP-linked respiratory rates driven by mitochondrial pyruvate+proline oxidation were significantly reduced at 24 h upon zymosan injection. Oxidative phosphorylation coupling was preserved regardless of innate immune response activation along 24 h. Importantly, rotenone-sensitive respiration and complex I-III activity were specifically reduced 24 h upon zymosan injection. Also, loss of complex I activity compromised ATP-linked and maximal respiratory rates mediated by mitochondrial proline oxidation. Finally, the magnitude of innate immune response activation negatively correlated with respiratory rates, regardless of the metabolic states. Collectively, we demonstrate that activation of innate immunity is strongly associated with reduced flight muscle complex I activity with direct consequences to mitochondrial proline oxidation and flight activity. Remarkably, our results indicate a trade-off between dispersal and immunity exists in an insect vector, underscoring the potential consequences of disrupted flight muscle mitochondrial energy metabolism to arbovirus transmission.

3.
Neotrop Entomol ; 53(3): 596-607, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38687424

RESUMO

Anthropogenic activities have decimated the Atlantic Forest domain (AF) and increased the pressure on freshwater biota, such as Trichoptera, which is the most affected order by the current insect decline. Adult mobility is crucial for the colonisation of new environments unconnected by water sources. In this article, we describe the assemblage of caddisflies in a preserved AF fragment related to their functional feeding group and provide empirical data on the patterns of horizontal and vertical flight. Adults were collected using white sheet and light attraction traps, placed at different distances and heights from a stream in Pernambuco, Brazil. A total of 2934 specimens of 15 species from five families were collected, mostly collector-filterers. Horizontal flight was limited, with 80% of the abundance concentrated up to 20 m. Vertical stratification was also concentrated at lower heights. A female-biased proportion was observed at higher strata. The richness and abundance of species decreased with increasing distances and heights from the stream. Overall, Chimarra sp. and Macrostemum scharfi were the dominant species. Trichoptera is a key taxon used as a biological indicator of water quality, and here, knowledge on the diversity and flight patterns of adults is expanded. At the risk of intensive pollution of rivers in Atlantic forests, data on the adult dispersal can be incorporated in the assessment of endangerment status and in conservation strategies.


Assuntos
Biodiversidade , Florestas , Animais , Brasil , Feminino , Masculino , Voo Animal , Ecossistema , Conservação dos Recursos Naturais , Insetos
4.
J Econ Entomol ; 117(3): 1192-1197, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38641562

RESUMO

Euwallacea fornicatus is an invasive tree pest able to infest healthy plants and cause damage to many host plants. This beetle has become established in several countries where it was introduced. It has now become established in Brazil, and while the original introduction site remains uncertain, there is a possibility of multiple introductions. We report the first evidence for the establishment of E. fornicatus with molecular confirmation, as well as its distribution, and host plants in Brazil. Euwallacea fornicatus has spread to main commercial avocado groves, other monocultures, and native vegetation in the country, and its pest status puts it as a threat, mainly to Brazilian avocado producers.


Assuntos
Distribuição Animal , Espécies Introduzidas , Persea , Gorgulhos , Animais , Gorgulhos/fisiologia , Brasil
5.
Mov Ecol ; 12(1): 23, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528635

RESUMO

We record and analyze the movement patterns of the marsupial Didelphis aurita at different temporal scales. Animals trajectories are collected at a daily scale by using spool-and-line techniques and, with the help of radio-tracking devices, animals traveled distances are estimated at intervals of weeks. Small-scale movements are well described by truncated Lévy flight, while large-scale movements produce a distribution of distances which is compatible with a Brownian motion. A model of the movement behavior of these animals, based on a truncated Lévy flight calibrated on the small scale data, converges towards a Brownian behavior after a short time interval of the order of 1 week. These results show that whether Lévy flight or Brownian motion behaviors apply, will depend on the scale of aggregation of the animals paths. In this specific case, as the effect of the rude truncation present in the daily data generates a fast convergence towards Brownian behaviors, Lévy flights become of scarce interest for describing the local dispersion properties of these animals, which result well approximated by a normal diffusion process and not a fast, anomalous one. Interestingly, we are able to describe two movement phases as the consequence of a statistical effect generated by aggregation, without the necessity of introducing ecological constraints or mechanisms operating at different spatio-temporal scales. This result is of general interest, as it can be a key element for describing movement phenomenology at distinct spatio-temporal scales across different taxa and in a variety of systems.

6.
Sci Total Environ ; 924: 171645, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38479523

RESUMO

The origin of introduction of a new pathogen in a country, the evolutionary dynamics of an epidemic within a country, and the role of cross-border areas on pathogen dynamics remain complex to disentangle and are often poorly understood. For instance, cross-border areas represent the ideal location for the sharing of viral variants between countries, with international air travel, land travel and waterways playing an important role in the cross-border spread of infectious diseases. Unfortunately, monitoring the point of entry and the evolutionary dynamics of viruses in space and time within local populations remain challenging. Here we tested the efficiency of wastewater-based epidemiology and genotyping in monitoring Covid-19 epidemiology and SARS-CoV-2 variant dynamics in French Guiana, a tropical country located in South America. Our results suggest that wastewater-based epidemiology and genotyping are powerful tools to monitor variant introduction and disease evolution within a tropical country but the inclusion of both clinical and wastewater samples could still improve our understanding of genetic diversity co-circulating. Wastewater sequencing also revealed the cryptic transmission of SARS-CoV-2 variants within the country. Interestingly, we found some amino acid changes specific to the variants co-circulating in French Guiana, suggesting a local evolution of the SARS-CoV-2 variants after their introduction. More importantly, our results showed that the proximity to bordering countries was not the origin of the emergence of the French Guianese B.1.160.25 variant, but rather that this variant emerged from an ancestor B.1.160 variant introduced by European air plane travelers, suggesting thus that air travel remains a significant risk for cross-border spread of infectious diseases. Overall, we suggest that wastewater-based epidemiology and genotyping provides a cost effective and non-invasive approach for pathogen monitoring and an early-warning tool for disease emergence and spread within a tropical country.


Assuntos
COVID-19 , Doenças Transmissíveis , Humanos , Guiana Francesa/epidemiologia , SARS-CoV-2/genética , Águas Residuárias , COVID-19/epidemiologia , América do Sul
7.
Insects ; 15(2)2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38392543

RESUMO

The rainfall regime has a significant impact on the microclimate and mass emergence of the coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae) (CBB). Little is known, however, about the shade tree-microclimate-CBB mass emergence interaction. The objective of the present study was to compare the effect of microclimate on the mass emergence of CBB in a full sun-exposed plot with a plot shaded by trees. The experiment was conducted on a Robusta coffee farm in southern Chiapas, Mexico. In each plot, 18 traps baited with an alcohol mixture were installed to capture flying females, collecting caught individuals every hour from 8:00 to 18:00 h. A meteorological station recorded several microclimatic variables on 13 weekly sampling dates from February to May 2022. Significantly more CBB females were captured in the shaded plot. The largest number of CBB captures was recorded between 14:00 and 16:00 h for the shade plot and between 15:00 and 17:00 h for the sun-exposed plot. The mass emergence of CBB showed a positive association with precipitation, dew point, and wind speed samples and a negative association with maximum air temperature, average relative humidity, ultraviolet radiation, wind speed, and equilibrium moisture content. Our observations show that the relationship between shade trees, microclimate, and mass emergence of CBB is complex and that its study helps us to gain deeper insight into CBB bioecology and advance control techniques against this important pest.

8.
Sensors (Basel) ; 24(3)2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38339690

RESUMO

Despite the significant advancements in drone sensory device reliability, data integrity from these devices remains critical in securing successful flight plans. A notable issue is the vulnerability of GNSS to jamming attacks or signal loss from satellites, potentially leading to incomplete drone flight plans. To address this, we introduce SiaN-VO, a Siamese neural network designed for visual odometry prediction in such challenging scenarios. Our preliminary studies have shown promising results, particularly for flights under static conditions (constant speed and altitude); while these findings are encouraging, they do not fully represent the complexities of real-world flight conditions. Therefore, in this paper, we have furthered our research to enhance SiaN-VO, improving data integration from multiple sensors and enabling more accurate displacement predictions in dynamic flight conditions, thereby marking a significant step forward in drone navigation technology.

9.
Pest Manag Sci ; 80(4): 2188-2198, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38158650

RESUMO

BACKGROUND: The stingless bee, Trigona spinipes, is an important pollinator of numerous native and cultivated plants. Trigona spinipes populations can be negatively impacted by insecticides commonly used for pest control in crops. However, this species has been neglected in toxicological studies. Here we observed the effects of seven insecticides on the survival of bees that had fed directly on insecticide-contaminated food sources or received insecticides via trophallactic exchanges between nestmates. The effects of insecticides on flight behavior were also determined for the compounds considered to be of low toxicity. RESULTS: Imidacloprid, spinosad and malathion were categorized as highly toxic to T. spinipes, whereas lambda-cyhalothrin, methomyl and chlorfenapyr were of medium to low toxicity and interfered with two aspects of flight behavior evaluated here. Chlorantraniliprole was the only insecticide tested here that had no significant effect on T. spinipes survival, although it did interfere with one aspect of flight capacity. A single bee that had ingested malathion, spinosad or imidacloprid, could contaminate three, four and nineteen other bees, respectively via trophallaxis, resulting in the death of the recipients. CONCLUSION: This is the first study to evaluate the ecotoxicology of a range of insecticides that not only negatively affected T. spinipes survival, but also interfered with flight capacity, a very important aspect of pollination behavior. The toxicity of the insecticides was observed following direct ingestion and also via trophallactic exchanges between nestmates, highlighting the possibility of lethal effects of these insecticides spreading throughout the colony, reducing the survival of non-foraging individuals. © 2023 Society of Chemical Industry.


Assuntos
Himenópteros , Inseticidas , Nitrocompostos , Humanos , Abelhas , Animais , Inseticidas/toxicidade , Malation/toxicidade , Neonicotinoides/toxicidade , Ingestão de Alimentos
10.
Rev. otorrinolaringol. cir. cabeza cuello ; 83(4): 415-431, dic. 2023. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1560344

RESUMO

Barotrauma se define como el daño tisular generado por diferencias de presión entre un espacio no ventilado dentro del cuerpo y el gas o fluido circundante. La causa más frecuente de barotrauma es el viaje en avión y se espera un aumento progresivo de los casos en el tiempo. Los órganos habitualmente comprometidos son el oído, cavidades paranasales y nervio facial. La fisiopatología del barotrauma por vuelo se fundamenta en la exposición a cambios bruscos de altitud y presión asociados a infecciones respiratorias altas y/o disfunción de la tuba auditiva. Los síntomas más frecuentes son otalgia, hipoacusia, tinnitus, vértigo y parálisis facial periférica. Muchas formas de barotrauma son autolimitadas y prevenibles mediante técnicas simples como la deglución de líquidos o maniobras de Valsalva durante las fases de ascenso o descenso. El tratamiento del barotrauma puede ser conservador, médico o quirúrgico, la decisión será individualizada de acuerdo con las características del paciente, gravedad del cuadro y recurrencias. Esto incluye el uso de descongestionantes orales y tópicos, dispositivos de autoinflación, técnicas quirúrgicas, entre otros. La mayoría de estas intervenciones se basan en recomendaciones de expertos y algoritmos extrapolados de guías clínicas para el manejo de otras patologías similares. Esta revisión presenta los principales hallazgos fisiopatológicos y clínicos, las opciones de tratamiento y las medidas preventivas para el barotrauma otorrinolaringológico inducido por el vuelo, en base a la evidencia disponible.


Barotrauma is defined as tissue damage caused by pressure differences between an unventilated space within the body and the surrounding gas or fluid. The most frequent cause of barotrauma is air travel, and a progressive increase in cases over time is expected. The most frequently affected organs are the ear, paranasal sinuses, and facial nerve. The pathophysiology of flight-induced barotrauma is based on exposure to sudden changes in altitude and pressure associated with upper respiratory tract infections and/or Eustachian tube dysfunction. The most frequent symptoms are otalgia, hypoacusis, tinnitus, dizziness, and peripheral facial palsy. Many forms of barotrauma are self-limiting and preventable through simple techniques such as swallowing fluids or performing Valsalva maneuvers during ascent or descent phases. The treatment of barotrauma can be either conservative, medical or surgical, according to patient's characteristics, severity of the condition, and recurrence. This includes the use of oral and topical decongestants, auto-inflation devices, surgical techniques, among others. Most of these interventions are based on expert recommendations and algorithms extrapolated from clinical guidelines for the management of other similar pathologies. This review presents key pathophysiologic and clinical findings, treatment options, and preventive measures for flight-induced otorhinolaryngologic barotrauma, based on available evidence.


Assuntos
Humanos , Barotrauma/diagnóstico , Barotrauma/epidemiologia , Orelha/lesões , Viagem Aérea
11.
BMC Biol ; 21(1): 268, 2023 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-37996928

RESUMO

BACKGROUND: Mayflies are basal winged insects of crucial importance for the understanding of the early evolution of Pterygota. Unlike all other insects, they have two successive winged stages, the subimago and the imago. Their forewings feature so-called bullae, which are desclerotized spots in the anterior main veins. Up to now, they have been considered to play a major role in wing bending during flight. RESULTS: We investigated bullae by multiple methods to reveal their structure and arrangement and to gain new information on the evolution of insect flight. Bullae are mostly present in the anterior negative wing veins, disrupting the otherwise rigid veins. High-speed videography reveals that mayfly wings do not bend during flight. Likewise, different arrangements of bullae in different species do not correlate with different modes of flying. Observations on the moulting of subimagines unravel that they are essential for wing bending during the extraction of the imaginal wing from the subimaginal cuticle. Bullae define predetermined bending lines, which, together with a highly flexible wing membrane enriched with resilin, permit wing bending during subimaginal moulting. Bullae are only absent in those species that remain in the subimaginal stage or that use modified modes of moulting. Bullae are also visible in fossil mayflies and can be traced back to stemgroup mayflies of the Early Permian, the 270 million years old Protereismatidae, which most probably had bullae in both fore- and hind wings. CONCLUSIONS: Bullae in mayfly wings do not play a role in flight as previously thought, but are crucial for wing bending during subimaginal moulting. Thus, the presence of bullae is a reliable morphological marker for a subimaginal life stage, confirming the existence of the subimago already in Permian Protereismatidae. A thorough search for bullae in fossils of other pterygote lineages may reveal wheather they also had subimagines and at what point in evolution this life stage was lost. In mayflies, however, the subimago may have been retained due to selective advantages in connection with the transition from aquatic to terrestrial life or due to morphological requirements for a specialized mating flight.


Assuntos
Ephemeroptera , Animais , Pterigotos , Vesícula , Insetos , Fósseis , Asas de Animais/anatomia & histologia , Voo Animal
12.
Bull Entomol Res ; 113(6): 748-755, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37743777

RESUMO

The aim was to evaluate the effect of different energy diets available in adulthood on the longevity, dispersal capacity and sexual performance of Aedes aegypti produced under a mass-rearing system. To evaluate the effects of diets in relation to the survival of the adult male insects of Ae. aegypti, six treatments were used: sucrose at a concentration of 10%, as a positive control (sack10); starvation, as a negative control (starvation); sucrose at a concentration of 20% associated with 1 g/l of ascorbic acid (sac20vitC); wild honey in a concentration of 10% (honey10); demerara sugar in a 10% concentration (demerara10); and sucrose at a concentration of 20% associated with 1 g/l of ascorbic acid and 0.5 g/l of amino acid proline (sac20vitCPr). Each treatment had 16 cages containing 50 adult males. For the tests of flight ability and propensity to copulation, five treatments were used (saca10; sac20vitC; mel10; demerara10; and sac20vitCPr), with males each for flight ability and females copulated by a single male for copulation propensity. The diet composed of sucrose at a concentration of 20% associated with ascorbic acid, as an antioxidant, improved the survival, flight ability and propensity to copulate in Ae. aegypti males under mass-rearing conditions, and may be useful to enhance the performance of sterile males, thus improving the success of sterile insect technique programmes.


Assuntos
Aedes , Feminino , Masculino , Animais , Insetos , Dieta , Ácido Ascórbico , Sacarose , Controle de Mosquitos/métodos
13.
J Med Entomol ; 60(5): 1008-1015, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37364566

RESUMO

Studies on the timing of anopheline host-seeking are important for understanding mosquito ecology, behaviors, and possible role in disease transmission. To study the evening crepuscular host-seeking activity of anophelines and the effects of moonlight, anopheline mosquitoes were collected with light traps settled in a livestock area in the Brazilian Cerrado region. Traps (Silva traps) were placed next to animal enclosures at 1.5 m asl. The research was divided in 2 experiments: the first experiment (12 nights) comprised 2 trapping periods, one from 6 PM to 7 PM and one from 7 PM to 6 AM, and the second experiment (16 evenings) divided in three 20-min intervals based on the 3 twilight phases (civil: 6-6:20 PM; nautical: 6:20-6:40 PM; and astronomical: 6:40-7 PM). A total of 2,815 anopheline mosquitoes and 9 species were found. The main species were Anopheles triannulatus s.l., An. argyritarsis, An. goeldii, and An. evanse. Host-seeking mosquitoes were more frequently active during the first hour after sunset, with a significant peak in the second 20-min interval. After that, a decrease in the number of individuals was observed from the astronomical twilight onwards. Moonlight did not affect the evening flight activity of anophelines. By using LED-based passive light traps, the evening arrival time of anophelines at blood-feeding sites was demonstrated, and it may be a key time window for malaria vector control interventions.


Assuntos
Anopheles , Malária , Animais , Brasil , Mosquitos Vetores , Comportamento Alimentar
14.
Animals (Basel) ; 13(7)2023 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-37048490

RESUMO

Immature individuals move from their natal area to the area where they settle and reproduce, and this may take several years. This process is essential for long-lived species such as vultures and condors, which spend long periods as immature and move extensively. We studied the movement behavior of 26 GPS-tagged immature Andean condors (Vultur gryphus) from northwestern Patagonia throughout the immature stage, analyzing whether these patterns differed according to age, sex and season. We found that season and age influenced home range size and flight distances, the warm season being when immature condors move most; movement patterns were greater in sub-adults than in juveniles. The age effect was associated with the sex of individuals, with males increasing their home range more than females. Our results provide the first description of how immature Andean condor movement patterns are affected by internal and external factors. This information could be key to understanding condor responses to environmental change and threats at different stages during their immature phase. Until now, condor conservation efforts have not considered the areas used by dispersing individuals. Our results increase our understanding of ranging behavior during the immature stage of this threatened bird, enabling us to improve the conservation policies and management strategies designed to protect them.

15.
Parasitol Res ; 122(6): 1343-1349, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37022501

RESUMO

Light traps have been widely used for monitoring malaria vectors, although drawbacks remain. In this context, new tools and attractants are always becoming available to perform monitoring tasks, like the Silva trap, a passive and low-cost LED-light trap for host-seeking anopheline mosquitoes. In this work, the effectiveness of the Silva trap by using UV-LED and at different heights as well as a comparison with the conventional CDC-type (HP) light trap was studied. A total of 9009 mosquitoes and nine species were caught, Anopheles triannulatus, An. argyritarsis, and An. goeldii being the most frequent species. The green (520 nm) and blue (470 nm) LEDs attracted almost equal numbers of anopheline mosquitoes, but UV LEDs (395 nm) attracted a significantly lower number of individuals (Kruskal-Wallis = 19.68, P = 0.0001). Even with the predominance of mosquitoes trapped at the height of 1.5 m, no significant statistical difference was found among the four heights tested (0.5 m; 1.0 m; 1.5 m; 2.0 m). Green-baited Silva traps collected significantly more individuals than incandescent-baited CDC-type traps (U = 60.5; P = 0.0303). LEDs have been useful as light sources for attracting insect vectors and together with a low-cost trap, as the Silva trap, a feasible alternative to conventional trap-based monitoring Anopheles mosquitoes that can be implemented in the field.


Assuntos
Anopheles , Malária , Humanos , Animais , Brasil , Mosquitos Vetores , Controle de Mosquitos
16.
Toxicon X ; 18: 100151, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36873112

RESUMO

Venoms from tarantulas contain low molecular weight vasodilatory compounds whose biological action is conceived as part of the envenomation strategy due to its propagative effects. However, some properties of venom-induced vasodilation do not match those described by such compounds, suggesting that other toxins may cooperate with these ones to produce the observed biological effect. Owing to the distribution and function of voltage-gated ion channels in blood vessels, disulfide-rich peptides isolated from venoms of tarantulas could be conceived into potential vasodilatory compounds. However, only two peptides isolated from spider venoms have been investigated so far. This study describes for the first time a subfraction containing inhibitor cystine knot peptides, PrFr-I, obtained from the venom of the tarantula Poecilotheria regalis. This subfraction induced sustained vasodilation in rat aortic rings independent of vascular endothelium and endothelial ion channels. Furthermore, PrFr-I decreased calcium-induced contraction of rat aortic segments and reduced extracellular calcium influx to chromaffin cells by the blockade of L-type voltage-gated calcium channels. This mechanism was unrelated to the activation of potassium channels from vascular smooth muscle, since vasodilation was not affected in the presence of TEA, and PrFr-I did not modify the conductance of the voltage-gated potassium channel Kv10.1. This work proposes a new envenomating function of peptides from venoms of tarantulas, and establishes a new mechanism for venom-induced vasodilation.

17.
Heliyon ; 9(3): e14181, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36950645

RESUMO

Pilot training has been, for decades, aided by flight simulators with different characteristics and degrees of fidelity. However, many studies indicate that, despite the recognized contribution of simulator training, actual flying practice is still necessary, depending on the trained task. This work introduces the proposal of using augmented reality for in-flight training, where elements in the environment outside the aircraft are displayed through an augmented reality headset to create a simulation scenario. The training of basic formation flight is used as an example, as it requires flying with at least two aircraft, resulting in high operational costs and risk of collision between aircraft. In this case, the augmented reality system replaces the real leader aircraft with a projection. In order to evaluate the Technology Readiness Level (TRL) of this proposal, this work presents a prototype of an augmented reality system integrated into a flight simulator to conduct an evaluation campaign. We investigate how the introduction of the augmented reality system impacts on human factors, such as stress and workload, as well as performance. Although the results obtained in a simulated environment are not equivalent to those from an in-flight campaign, the experimental campaign performed in the flight simulator provides a way of evaluating the impact on the pilot of some aspects of the proposed solution, such as the performance of occlusion routines and some ergonomic aspects of the augmented reality headset.

18.
Artigo em Inglês | MEDLINE | ID: mdl-36834104

RESUMO

Addressing the field of health and safety at work, the primary objective of the present systematic review was to analyze the organizational risk factors for aircrew health according to professional category (flight attendants and pilots/co-pilots) and their consequences. The secondary objective was to identify the countries in which studies were carried out, focusing on the quality of content of the publications. The Medline/Pubmed, Cochrane, Web of Science, and Scopus databases were searched for eligible studies according to PRISMA statements. The risk of bias and the methodological quality of the studies were assessed using the Newcastle-Ottawa scale and Loney tools. Of the 3230 abstracts of articles screened, 36 studies met the inclusion criteria. Most of the research conducted on risk factors for the work organization of aircrew was carried out in the United States and the European Union and had moderate or low-quality methodology and evidence. However, the findings are homogeneous and allow the most prevalent organizational risk factors for the health of aircrew to be determined, namely, high work demand, long hours, and night work. Consequently, the most pervasive health problems were sleep disturbances, mental health disorders, musculoskeletal disorders, and fatigue. Thus, the regulation of the aircrew profession must prioritize measures that minimize these risk factors to promote better health and sleep for these professionals and, consequently, to provide excellent safety for workers and passengers.


Assuntos
Doenças Musculoesqueléticas , Ocupações , Humanos , Fatores de Risco
19.
J Insect Physiol ; 146: 104492, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36801397

RESUMO

Rhodnius prolixus is a hemimetabolous, hematophagous insect, and both nymphs and adults feed exclusively on blood. The blood feeding triggers the molting process and, after five nymphal instar stages, the insect reaches the winged adult form. After the final ecdysis, the young adult still has a lot of blood in the midgut and, thus, we have investigated the changes in protein and lipid contents that are observed in the insect organs as digestion continues after molting. Total midgut protein content decreased during the days after the ecdysis, and digestion was finished fifteen days later. Simultaneously, proteins and triacylglycerols present in the fat body were mobilized, and their contents decreased, whereas they increased in both the ovary and the flight muscle. In order to evaluate the activity of de novo lipogenesis of each organ, the fat body, ovary and flight muscle were incubated in the presence of radiolabeled acetate, and the fat body showed the highest efficiency rate (around 47%) to convert the taken up acetate into lipids. The levels of de novo lipid synthesis in the flight muscle and ovary were very low. When 3H-palmitate was injected into the young females, its incorporation by the flight muscle was higher than by the ovary or the fat body. In the flight muscle, the 3H-palmitate was similarly distributed amongst triacylglycerols, phospholipids, diacylglycerols and free fatty acids, while in the ovary and fat body it was mostly found in triacylglycerols and phospholipids. The flight muscle was not fully developed after the molt, and at day two no lipid droplets were observed. At day five, very small lipid droplets were present, and they increased in size up to day fifteen. The diameter of the muscle fibers also increased from day two to fifteen, as well as the internuclear distance, indicating that muscle hypertrophy occurred along these days. The lipid droplets from the fat body showed a different pattern, and their diameter decreased after day two, but started to increase again at day ten. The data presented herein describes the development of the flight muscle after the final ecdysis, and modifications that occur regarding lipid stores. We show that, after molting, substrates that are present in the midgut and fat body are mobilized and directed to the ovary and flight muscle, for the adults of R. prolixus to be ready to feed and reproduce.


Assuntos
Muda , Rhodnius , Feminino , Animais , Ovário , Rhodnius/fisiologia , Triglicerídeos/metabolismo , Palmitatos/metabolismo , Digestão
20.
Insects ; 14(2)2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36835681

RESUMO

Although theoretical work on optimal migration has been largely restricted to birds, relevant free-flight data are now becoming available for migratory insects. Here we report, for the first time in passion-vine butterflies, that Heliconius sara migrates directionally. To test optimal migration models for insects, we quantified the aerodynamic power curve for free-flying H. sara as they migrated across the Panama Canal. Using synchronized stereo-images from high-speed video cameras, we reconstructed three-dimensional flight kinematics of H. sara migrating naturally across the Panama Canal. We also reconstructed flight kinematics from a single-camera view of butterflies flying through a flight tunnel. We calculated the power requirements for flight for H. sara over a range of flight velocities. The relationship between aerodynamic power and velocity was "J"-shaped across the measured velocities with a minimum power velocity of 0.9 m/s and a maximum range velocity of 2.25 m/s. Migrating H. sara did not compensate for crosswind drift. Changes in airspeed with tailwind drift were consistent with the null hypothesis that H. sara did not compensate for tailwind drift, but they were also not significantly different from those predicted to maximize the migratory range of the insects.

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