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1.
BMC Plant Biol ; 24(1): 525, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858659

RESUMO

Common bean provides diet rich in vitamins, fiber, minerals, and protein, which could contribute into food security of needy populations in many countries. Developing genotypes that associate favorable agronomic and grain quality traits in the common bean crop could increase the chances of adopting new cultivars black bean. In this context, the present study aimed at selection of superior black bean lines using multi-variate indexes, Smith-Hazel-index, and genotype by yield*trait biplot analysis. These trials were conducted in Campos dos Goytacazes - RJ, in 2020 and 2021. The experimental design used was randomized blocks, with 28 treatments and three replications. The experimental unit consisted of four rows 4.0 m long, spaced at 0.50 m apart, with a sowing density of 15 seeds per meter. The two central rows were used for the evaluations. The selection of superior genotypes was conducted using the multiple trait stability index (MTSI), multi-trait genotype-ideotype distance index (MGIDI), multi-trait index based on factor analysis and genotype-ideotype distance (FAI-BLUP), Smith-Hazel index, and Genotype by Yield*Trait Biplot (GYT). The multivariate indexes efficiently selected the best black bean genotypes, presenting desirable selection gains for most traits. The use of multivariate indexes and GYT enable the selection of early genotypes with higher grain yields. These lines G9, G13, G17, G23, and G27 were selected based on their performance for multiple traits closest to the ideotype and could be recommended as new varieties.


Assuntos
Genótipo , Phaseolus , Phaseolus/genética , Melhoramento Vegetal/métodos , Seleção Genética , Produtos Agrícolas/genética , Fenótipo
2.
Trop Med Int Health ; 29(5): 414-423, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38469931

RESUMO

OBJECTIVES: Arboviruses, such as dengue (DENV), zika (ZIKV), and chikungunya (CHIKV), constitute a growing urban public health threat. Focusing on Aedes aegypti mosquitoes, their primary vectors, is crucial for mitigation. While traditional immature-stage mosquito surveillance has limitations, capturing adult mosquitoes through traps yields more accurate data on disease transmission. However, deploying traps presents logistical and financial challenges, demonstrating effective temporal predictions but lacking spatial accuracy. Our goal is to identify smaller representative areas within cities to enhance the early warning system for DENV outbreaks. METHODS: We created Sentinel Geographic Units (SGUs), smaller areas of 1 km2 within each stratum, larger areas, with the aim of aligning the Trap Positivity Index (TPI) and Adult Density Index (ADI) with their respective strata. We conducted a two-step evaluation of SGUs. First, we examined the equivalence of TPI and ADI between SGUs and strata from January 2017 to July 2022. Second, we assessed the ability of SGU's TPI and ADI to predict DENV outbreaks in comparison to Foz do Iguaçu's Early-Warning System, which forecasts outbreaks up to 4 weeks ahead. Spatial and temporal analyses were carried out, including data interpolation and model selection based on Akaike information criteria (AIC). RESULTS: Entomological indicators produced in small SGUs can effectively replace larger sentinel areas to access dengue outbreaks. Based on historical data, the best predictive capability is achieved 2 weeks after infestation verification. Implementing the SGU strategy with more frequent sampling can provide more precise space-time estimates and enhance dengue control. CONCLUSIONS: The implementation of SGUs offers an efficient way to monitor mosquito populations, reducing the need for extensive resources. This approach has the potential to improve dengue transmission management and enhance the public health response in endemic cities.


Assuntos
Aedes , Cidades , Dengue , Mosquitos Vetores , Animais , Aedes/virologia , Brasil/epidemiologia , Dengue/epidemiologia , Dengue/transmissão , Dengue/prevenção & controle , Humanos , Surtos de Doenças/prevenção & controle , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/transmissão , Controle de Mosquitos/métodos
3.
BMC Biol ; 21(1): 97, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-37101136

RESUMO

BACKGROUND: Aedes aegypti, the main arboviral mosquito vector, is attracted to human dwellings and makes use of human-generated breeding sites. Past research has shown that bacterial communities associated with such sites undergo compositional shifts as larvae develop and that exposure to different bacteria during larval stages can have an impact on mosquito development and life-history traits. Based on these facts, we hypothesized that female Ae. aegypti shape the bacteria communities of breeding sites during oviposition as a form of niche construction to favor offspring fitness. RESULTS: To test this hypothesis, we first verified that gravid females can act as mechanical vectors of bacteria. We then elaborated an experimental scheme to test the impact of oviposition on breeding site microbiota. Five different groups of experimental breeding sites were set up with a sterile aqueous solution of larval food, and subsequently exposed to (1) the environment alone, (2) surface-sterilized eggs, (3) unsterilized eggs, (4) a non-egg laying female, or (5) oviposition by a gravid female. The microbiota of these differently treated sites was assessed by amplicon-oriented DNA sequencing once the larvae from the sites with eggs had completed development and formed pupae. Microbial ecology analyses revealed significant differences between the five treatments in terms of diversity. In particular, between-treatment shifts in abundance profiles were detected, showing that females induce a significant decrease in microbial alpha diversity through oviposition. In addition, indicator species analysis pinpointed bacterial taxa with significant predicting values and fidelity coefficients for the samples in which single females laid eggs. Furthermore, we provide evidence regarding how one of these indicator taxa, Elizabethkingia, exerts a positive effect on the development and fitness of mosquito larvae. CONCLUSIONS: Ovipositing females impact the composition of the microbial community associated with a breeding site, promoting certain bacterial taxa over those prevailing in the environment. Among these bacteria, we found known mosquito symbionts and showed that they can improve offspring fitness if present in the water where eggs are laid. We deem this oviposition-mediated bacterial community shaping as a form of niche construction initiated by the gravid female.


Assuntos
Aedes , Animais , Humanos , Feminino , Mosquitos Vetores , Água , Bactérias/genética , Oviposição , Larva
4.
Med Vet Entomol ; 37(4): 683-692, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37265439

RESUMO

Vector control is still the recommended approach to avoid arbovirus outbreaks. Herein, we investigate oviposition preferences of Aedes aegypti (Diptera: Culicidae) females under a semi-field structure Rio de Janeiro, Brazil. For that, in Experiment 1, we used two settings: 'Single items', which included as containers drain, beer bottle, bucket, car tyre, water tank, and a potted Peace Lily (Spathiphyllum wallisii) in a saucer with water, or 'Multiple containers', as an urban simulation, in which one drain, two additional beer bottles, and an extra plant pot saucer were added. Experiment 2 (sensory cues) used five variations of potted plant, each one varying in the range of sensory cues known to attract gravid females to oviposition containers. Our results indicate that gravid Ae. aegypti prefer to oviposit close to the ground and in open water containers with organic compounds from plant watering. Domestic large artificial containers containing tap water received significantly fewer eggs, except for the car tyre, which exhibited as many eggs as the potted plant. We also show that visual (potted plant shape) and olfactory clues (odour of the plant or from water containing organic matter) were equally attractive separately as were these stimuli together.


Assuntos
Aedes , Feminino , Animais , Oviposição , Mosquitos Vetores , Brasil , Água
5.
J Therm Biol ; 114: 103546, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37344020

RESUMO

This study evaluated the possible association between the diurnal variations of climatic factors during the rainy (RS) or less rainy (LS) seasons on the testicular hemodynamics and thermoregulatory responses of hair sheep rams raised in a humid tropical climate. Santa Inês rams (n = 6) underwent evaluation of general and testicular physiological parameters (heart and respiratory rates, internal and scrotal temperatures, internal-scrotal temperature gradient, scrotal distention, and color Doppler ultrasound evaluation of the spermatic cords and spectral analyses of testicular arteries) over six consecutive weeks per season at three separate times daily (morning = 8:00 a.m., noon = 12:00 p.m., and afternoon = 5:00 p.m.) during the RS and LS. Climatic air temperature and relative humidity data were recorded, and the temperature and humidity index (THI) was calculated. Higher thermal challenge was observed in LS relative to RS (air temperature = 28.0 vs. 30.9 °C; relative humidity = 84.1 vs. 69.9%; THI = 80.0 vs. 82.5; P < 0.05). In both seasons, respiratory rate and internal temperature were normal, demonstrating the animals' adaptability. In RS, however, a higher scrotal temperature was recorded in relation to LS (35.0 vs. 34.7 °C; P < 0.05), with a gradual increase from morning to afternoon. Lower resistivity (0.40 vs. 0.64; P < 0.05) and pulsatility (0.55 vs. 1.14; P < 0.05) indices, and a higher rate of high-velocity blood flow of testicular arteries (71.1 vs. 60.6%; P < 0.05) were observed in RS compared to LS. The lowest correlations between testicular hemodynamic, physiological variables, and environmental parameters (P < 0.05) were observed in the morning. In conclusion, testicular thermoregulation and testicular hemodynamics were influenced by the climatic seasons and time of the day, being more efficient in the LS season and with less interference from environmental factors in the morning.


Assuntos
Testículo , Clima Tropical , Ovinos , Animais , Masculino , Estações do Ano , Testículo/fisiologia , Carneiro Doméstico/fisiologia , Regulação da Temperatura Corporal , Hemodinâmica
6.
Molecules ; 28(4)2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36838646

RESUMO

Urease is an enzyme containing a dinuclear nickel active center responsible for the hydrolysis of urea into carbon dioxide and ammonia. Interestingly, inorganic models of urease are unable to mimic its mechanism despite their similarities to the enzyme active site. The reason behind the discrepancy in urea decomposition mechanisms between inorganic models and urease is still unknown. To evaluate this factor, we synthesized two bis-nickel complexes, [Ni2L(OAc)] (1) and [Ni2L(Cl)(Et3N)2] (2), based on the Trost bis-Pro-Phenol ligand (L) and encompassing different ligand labilities with coordination geometries similar to the active site of jack bean urease. Both mimetic complexes produced ammonia from urea, (1) and (2), were ten- and four-fold slower than urease, respectively. The presence and importance of several reaction intermediates were evaluated both experimentally and theoretically, indicating the aquo intermediate as a key intermediate, coordinating urea in an outer-sphere manner. Both complexes produced isocyanate, revealing an activated water molecule acting as a base. In addition, the reaction with different substrates indicated the biomimetic complexes were able to hydrolyze isocyanate. Thus, our results indicate that the formation of an outer-sphere complex in the urease analogues might be the reason urease performs a different mechanism.


Assuntos
Níquel , Urease , Níquel/química , Urease/química , Ligantes , Amônia , Ureia/química
7.
Emerg Infect Dis ; 28(4): 701-706, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35318912

RESUMO

Arbovirus epidemiology lacks efficient and timely surveillance systems with accurate outbreak alert signals. We devised a citywide integrated surveillance system combining entomologic, epidemiologic, and entomo-virologic data gathered during 2017-2020 in Foz do Iguaçu, Brazil. We installed 3,476 adult mosquito traps across the city and inspected traps every 2 months. We compared 5 entomologic indices: traditional house and Breteau indices for larval surveys and trap positivity, adult density, and mosquitoes per inhabitant indices for adult trapping. We screened for dengue, Zika, and chikungunya viruses in live adult Aedes aegypti mosquitoes collected from traps. Indices based on adult mosquito sampling had higher outbreak predictive values than larval indices, and we were able to build choropleth maps of infestation levels <36 h after each round of trap inspection. Locating naturally infected vectors provides a timely support tool for local public health managers to prioritize areas for intervention response to prevent virus outbreaks.


Assuntos
Aedes , Arbovírus , Infecção por Zika virus , Zika virus , Animais , Brasil/epidemiologia , Mosquitos Vetores , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/prevenção & controle
8.
Phys Rev Lett ; 127(15): 157204, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34677991

RESUMO

Quantum spin liquids are exotic states of matter that form when strongly frustrated magnetic interactions induce a highly entangled quantum paramagnet far below the energy scale of the magnetic interactions. Three-dimensional cases are especially challenging due to the significant reduction of the influence of quantum fluctuations. Here, we report the magnetic characterization of K_{2}Ni_{2}(SO_{4})_{3} forming a three-dimensional network of Ni^{2+} spins. Using density functional theory calculations, we show that this network consists of two interconnected spin-1 trillium lattices. In the absence of a magnetic field, magnetization, specific heat, neutron scattering, and muon spin relaxation experiments demonstrate a highly correlated and dynamic state, coexisting with a peculiar, very small static component exhibiting a strongly renormalized moment. A magnetic field B≳4 T diminishes the ordered component and drives the system into a pure quantum spin liquid state. This shows that a system of interconnected S=1 trillium lattices exhibits a significantly elevated level of geometrical frustration.

9.
Phys Chem Chem Phys ; 22(16): 9074-9085, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32297886

RESUMO

The intermolecular dynamics in the THz frequency range of the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N1114][NTf2], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N1444][NTf2], were investigated by a combined usage of inelastic neutron scattering (INS), Raman, and far-infrared (FIR) spectroscopies and the power spectrum calculated by molecular dynamics (MD) simulations. The collective dynamics of the simulated systems is also discussed by the calculation of time correlation functions of charge and mass currents that are projected onto acoustic- and optic-like motions. The INS and Raman measurements have been performed as a function of temperature in the glassy, crystalline, and liquid phases. The excess in the vibrational density of states over the expectation of the Debye theory, the so-called boson peak, is found in the INS and Raman spectra as a peak at ∼2 meV (∼16 cm-1) and also in the direct measurement of heat capacity at very low temperatures (4-20 K). This low-frequency vibration is incorporated into the curve fits of Raman, FIR, and MD data at room temperature. Fits of spectra from these different sources in the range below 100 cm-1 are consistently achieved with three components at ca. 25, 50, and 80 cm-1, but with distinct relative intensities among the different techniques. It is proposed as the collective nature of the lowest-frequency component and the anion-cation intermolecular vibration nature of the highest-frequency component. The MD results indicate that there is no clear distinction between acoustic and optic vibrations in the spectral range investigated in this work for the ionic liquids [N1114][NTf2] and [N1444][NTf2]. The analysis carried out here agrees in part, but not entirely, with other propositions in the literature, mainly from optical Kerr effect (OKE) and FIR spectroscopies, concerning the intermolecular dynamics of ionic liquids.

10.
Nanotechnology ; 29(20): 205704, 2018 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-29504515

RESUMO

In the investigation reported in this paper a modified thermal decomposition method was developed to produce very small Er2O3 nanoparticles (NPs). Particles structure, shape and size were characterized by x-ray diffraction and transmission electron microscopy which showed that the synthesis by thermal decomposition under O2 atmosphere produced very small and monodisperse NPs, allowing the investigation of finite-size and surface effects. Results of magnetization measurements showed that the smallest particles present the highest values of susceptibility that decrease as particle size increases. Specific heat measurements indicate that the sample with the smallest NPs (diameter ∼5 nm) has a Néel temperature of 0.54 K. The local structure of particles was investigated by measurements of hyperfine interactions with perturbed angular correlation spectroscopy using 111Cd as probe nuclei replacing the cationic sites. Results showed that the relative population of sites 8b increases in both the core and surface layer of particles.

11.
Exp Parasitol ; 182: 26-33, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28939444

RESUMO

Cell invasion by Trypanosoma cruzi and its intracellular replication are essential for progression of the parasite life cycle and development of Chagas disease. Prostaglandin E2 (PGE2) and other eicosanoids potently modulate host response and contribute to Chagas disease progression. In this study, we evaluated the effect of aspirin (ASA), a non-selective cyclooxygenase (COX) inhibitor on the T. cruzi invasion and its influence on nitric oxide and cytokine production in human monocytes. The pretreatment of monocytes with ASA or SQ 22536 (adenylate-cyclase inhibitor) induced a marked inhibition of T. cruzi infection. On the other hand, the treatment of monocytes with SQ 22536 after ASA restored the invasiveness of T. cruzi. This reestablishment was associated with a decrease in nitric oxide and PGE2 production, and also an increase of interleukin-10 and interleukin-12 by cells pre-treated with ASA. Altogether, these results reinforce the idea that the cyclooxygenase pathway plays a fundamental role in the process of parasite invasion in an in vitro model of T. cruzi infection.


Assuntos
Adenilil Ciclases/metabolismo , Aspirina/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Monócitos/parasitologia , Trypanosoma cruzi/efeitos dos fármacos , Adenina/análogos & derivados , Adenina/química , Adenina/farmacologia , Inibidores de Adenilil Ciclases/química , Inibidores de Adenilil Ciclases/farmacologia , Adulto , Animais , Linhagem Celular , Sobrevivência Celular , AMP Cíclico/metabolismo , Citocinas/metabolismo , Dinoprostona/metabolismo , Células Epiteliais/citologia , Células Epiteliais/parasitologia , Humanos , Rim/citologia , Rim/parasitologia , Macaca mulatta , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Óxido Nítrico/metabolismo , Trypanosoma cruzi/fisiologia
13.
Mem Inst Oswaldo Cruz ; 111(9): 577-87, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27580348

RESUMO

Mosquito midgut microbiota is a key component of vector competence, as gut bacteria can disturb pathogen development. In this study, we addressed the microbiota composition of Aedes aegypti during its lifespan, under field conditions. We also investigated the possible effects of environment, dietary regime and ageing on the gut community composition. We employed culture independent and dependent approaches to characterise vector microbiota. There was evidence of a lifelong stable core microbiota after mosquitoes were released into an urban settlement, where they presumably fed on a range of vertebrate hosts and carbohydrate sources. This core was formed mainly of bacteria belonging to the genera Pseudomonas, Acinetobacter, Aeromonas and Stenotrophomonas and to the families Oxalobacteraceae, Enterobacteriaceae and Comamonadaceae. We showed that both dietary regime and age were associated with the abundance of some bacterial groups in the Ae. aegypti microbiota. The majority of the bacterial groups we identified have been detected in the midgut of Ae. aegypti from laboratory and wild populations, indicating a possible core microbiota associated with this mosquito species. Our findings suggest that Ae. aegypti harbours a stable bacterial community during its adult life, similar to mosquito populations from distinct geographic areas, which may be further explored for arbovirus biocontrol strategies.


Assuntos
Aedes/microbiologia , Bactérias/classificação , Dieta , Microbioma Gastrointestinal , Insetos Vetores/microbiologia , Animais , Bactérias/genética , Bactérias/isolamento & purificação , DNA Bacteriano/genética , DNA Ribossômico/genética , Microbiota/fisiologia
14.
J Nanosci Nanotechnol ; 15(12): 9482-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26682369

RESUMO

Alcohol dehydrogenase (ADH) from Saccharomyces cerevisiae was covalently attached, via glutaraldehyde, to magnetite nanoparticles (MagNP) previously coated with aminopropyltriethoxysilane (MagNP/APTS), or with a silica shell followed by the APTS coating (MagNP@SiO2/APTS). In both cases, a great improvement of enzymatic activity has been observed for the ethanol-acetaldehyde conversion. The MagNP@SiO2/APTS-ADH system exhibited the best stability with respect to pH and temperature. Its residual activity after 10 successive recovery cycles and 24 h storage, was maintained around 80% in comparison with 20% for the MagNP/APTS system, and a null activity for free ADH. Luminescence measurements for the immobilized enzyme indicated the occurrence of conformational changes on ADH, contributing for its improved catalytic performance.


Assuntos
Álcool Desidrogenase/química , Nanopartículas de Magnetita/química , Acetaldeído , Estabilidade Enzimática , Enzimas Imobilizadas , Etanol , Concentração de Íons de Hidrogênio , Saccharomyces cerevisiae/enzimologia , Dióxido de Silício/química , Temperatura
15.
Antimicrob Agents Chemother ; 58(10): 6157-64, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25092706

RESUMO

The intracellular protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a serious disorder that affects millions of people in Latin America. Cell invasion by T. cruzi and its intracellular replication are essential to the parasite's life cycle and for the development of Chagas disease. Here, we present evidence suggesting the involvement of the host's cyclooxygenase (COX) enzymes during T. cruzi invasion. Pharmacological antagonists for COX-1 (aspirin) and COX-2 (celecoxib) caused marked inhibition of T. cruzi infection when rat cardiac cells were pretreated with these nonsteroidal anti-inflammatory drugs (NSAIDs) for 60 min at 37°C before inoculation. This inhibition was associated with an increase in the production of NO and interleukin-1ß and decreased production of transforming growth factor ß (TGF-ß) by cells. Taken together, these results indicate that COX-1 more than COX-2 is involved in the regulation of anti-T. cruzi activity in cardiac cells, and they provide a better understanding of the influence of TGF-ß-interfering therapies on the innate inflammatory response to T. cruzi infection and may represent a very pertinent target for new therapeutic treatments of Chagas disease.


Assuntos
Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Mioblastos Cardíacos/parasitologia , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/patogenicidade , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Celecoxib , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Imunidade Inata/efeitos dos fármacos , Imuno-Histoquímica , Interleucina-1beta/metabolismo , Óxido Nítrico/metabolismo , Pirazóis/farmacologia , Ratos , Sulfonamidas/farmacologia , Fator de Crescimento Transformador alfa/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Trypanosoma cruzi/efeitos dos fármacos
16.
Bull World Health Organ ; 92(9): 685-9, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25378760

RESUMO

PROBLEM: In 2010, dengue virus (DENV) serotype-4 was detected during a dengue outbreak in the Amazonian city of Boa Vista. At that time Brazil was already endemic for DENV-1, DENV-2 and DENV-3. This was the first time DENV-4 was observed in the country after it was initially detected and eliminated in 1981. APPROACH: To hinder the spread of DENV-4 throughout Brazil, standard vector control measures were intensified. Vector control professionals visited 56 837 households in 22 out of 31 districts of Boa Vista, to eliminate mosquito-breeding sites. Water storage containers were treated with the larvicide diflubenzuron, and deltamethrin was sprayed for adult Aedes aegypti mosquitoes. Fifteen days later, a second larvae survey and additional deltamethrin applications were performed. LOCAL SETTING: In Brazil, dengue vector control is managed at all three government levels. Regular surveillance of Aedes aegypti is done four to six times a year to strengthen mosquito control activities in areas with high-vector density. Educational dengue control campaigns in communities are scarce, especially between outbreaks. RELEVANT CHANGES: In spite of extensive implementation of all standard control actions recommended by the Brazilian dengue control programme, only a slight decrease in mosquito density was detected. LESSONS LEARNT: There is a need to redesign all levels of dengue control. Public consultation and engagement, behaviour change and actions that go beyond technical impositions are required. Vector control programme managers need to reflect on what constitutes good practices and whether intermittent information campaigns are effective measures for dengue prevention and control.


Assuntos
Vírus da Dengue/classificação , Dengue/prevenção & controle , Surtos de Doenças/prevenção & controle , Controle de Mosquitos/métodos , Aedes , Animais , Brasil/epidemiologia , Dengue/epidemiologia , Humanos
17.
Mem Inst Oswaldo Cruz ; 109(8): 1070-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25591112

RESUMO

Two hypotheses for how conditions for larval mosquitoes affect vectorial capacity make opposite predictions about the relationship of adult size and frequency of infection with vector-borne pathogens. Competition among larvae produces small adult females. The competition-susceptibility hypothesis postulates that small females are more susceptible to infection and predicts frequency of infection should decrease with size. The competition-longevity hypothesis postulates that small females have lower longevity and lower probability of becoming competent to transmit the pathogen and thus predicts frequency of infection should increase with size. We tested these hypotheses for Aedes aegypti in Rio de Janeiro, Brazil, during a dengue outbreak. In the laboratory, longevity increases with size, then decreases at the largest sizes. For field-collected females, generalised linear mixed model comparisons showed that a model with a linear increase of frequency of dengue with size produced the best Akaike's information criterion with a correction for small sample sizes (AICc). Consensus prediction of three competing models indicated that frequency of infection increases monotonically with female size, consistent with the competition-longevity hypothesis. Site frequency of infection was not significantly related to site mean size of females. Thus, our data indicate that uncrowded, low competition conditions for larvae produce the females that are most likely to be important vectors of dengue. More generally, ecological conditions, particularly crowding and intraspecific competition among larvae, are likely to affect vector-borne pathogen transmission in nature, in this case via effects on longevity of resulting adults. Heterogeneity among individual vectors in likelihood of infection is a generally important outcome of ecological conditions impacting vectors as larvae.


Assuntos
Aedes/crescimento & desenvolvimento , Tamanho Corporal/fisiologia , Dengue/transmissão , Epidemias , Insetos Vetores/crescimento & desenvolvimento , Aedes/anatomia & histologia , Aedes/virologia , Animais , Teorema de Bayes , Brasil/epidemiologia , Comportamento Competitivo/fisiologia , Aglomeração , Dengue/epidemiologia , Vírus da Dengue/isolamento & purificação , Monitoramento Ambiental , Feminino , Insetos Vetores/virologia , Larva/anatomia & histologia , Larva/crescimento & desenvolvimento , Longevidade/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Mem Inst Oswaldo Cruz ; 109(6): 824-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25317711

RESUMO

Currently, sticky traps are regularly employed to assist in the surveillance of Aedes aegypti infestation. We tested two alternative procedures for specimen identification performed by local health agents: directly in the field, as recommended by certain manufacturers, or after transportation to the laboratory. A total of 384 sticky traps (MosquiTRAP) were monitored monthly during one year in four geographically representative Brazilian municipalities. When the same samples were inspected in the field and in the laboratory, large differences were noted in the total number of mosquitoes recorded and in the number of specimens identified as Ae. aegypti by both procedures. Although field identification has the potential to speed vector surveillance, these results point to uncertainties in the evaluated protocol.


Assuntos
Aedes/classificação , Insetos Vetores/classificação , Animais , Brasil , Cidades , Monitoramento Ambiental , Laboratórios , Controle de Mosquitos/métodos
19.
Clin Oral Investig ; 18(3): 1005-13, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23949015

RESUMO

PURPOSE: This paper aims to evaluate the effects of laser (660 nm) and light-emitting diode (LED) (670 nm) irradiation in the cheek pouch mucosa of hamsters with oral mucositis (OM) induced by chemotherapy (Che) with 5-fluorouracil (5-FU). MATERIALS AND METHODS: In the preventive groups, the photobiomodulation was started 1 day before the drug administration and was performed every 48 h (Ia, IIa, Ib, and IIb). In the therapeutic groups (IIIa, IIIb, IVa, and IVb), the irradiations were started on the third day after the Che d(0) and was performed every 48 h. In both groups, animals were sacrificed 7 or 14 days after Che. In the positive control groups, the hamsters were subjected to Che but did not receive irradiation, and they were sacrificed in 7 days (Va) or 14 days (Vb). In the negative control groups, no procedures were done and the animals were sacrificed 7 days (Vc) or 14 days (Vd) after the experiment started. RESULTS: The results indicated loss of body mass, xerostomia, and alopecia in the animals subjected to Che and the healing of OM to different degrees after the photobiomodulation treatment. Histologically, the positive control and experimental groups showed inflammation, predominately with lymphocytes and plasma cells, which tended to diminish with time. Epithelial atrophy, hyperemia, fibroblast proliferation, and vascular congestion were also observed at those intervals. CONCLUSIONS: The best results were obtained from the preventive laser and LED photobiomodulation groups; both treatments were effective in diminishing the OM lesions. CLINICAL RELEVANCE: A noninvasive and effective method with sparse side effects of OM would be desirable for use in cancer centers around the world.


Assuntos
Modelos Animais , Estomatite/prevenção & controle , Estomatite/terapia , Animais , Cricetinae , Feminino , Terapia a Laser , Masculino , Mesocricetus
20.
Parasit Vectors ; 17(1): 399, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39300572

RESUMO

BACKGROUND: The recent rise in the transmission of mosquito-borne diseases such as dengue virus (DENV), Zika (ZIKV), chikungunya (CHIKV), Oropouche (OROV), and West Nile (WNV) is a major concern for public health managers worldwide. Emerging technologies for automated remote mosquito classification can be supplemented to improve surveillance systems and provide valuable information regarding mosquito vector catches in real time. METHODS: We coupled an optical sensor to the entrance of a standard mosquito suction trap (BG-Mosquitaire) to record 9151 insect flights in two Brazilian cities: Rio de Janeiro and Brasilia. The traps and sensors remained in the field for approximately 1 year. A total of 1383 mosquito flights were recorded from the target species: Aedes aegypti and Culex quinquefasciatus. Mosquito classification was based on previous models developed and trained using European populations of Aedes albopictus and Culex pipiens. RESULTS: The VECTRACK sensor was able to discriminate the target mosquitoes (Aedes and Culex genera) from non-target insects with an accuracy of 99.8%. Considering only mosquito vectors, the classification between Aedes and Culex achieved an accuracy of 93.7%. The sex classification worked better for Cx. quinquefasciatus (accuracy: 95%; specificity: 95.3%) than for Ae. aegypti (accuracy: 92.1%; specificity: 88.4%). CONCLUSIONS: The data reported herein show high accuracy, sensitivity, specificity and precision of an automated optical sensor in classifying target mosquito species, genus and sex. Similar results were obtained in two different Brazilian cities, suggesting high reliability of our findings. Surprisingly, the model developed for European populations of Ae. albopictus worked well for Brazilian Ae. aegypti populations, and the model developed and trained for Cx. pipiens was able to classify Brazilian Cx. quinquefasciatus populations. Our findings suggest this optical sensor can be integrated into mosquito surveillance methods and generate accurate automatic real-time monitoring of medically relevant mosquito species.


Assuntos
Aedes , Culex , Mosquitos Vetores , Animais , Aedes/classificação , Aedes/fisiologia , Culex/classificação , Mosquitos Vetores/classificação , Brasil , Feminino , Masculino , Controle de Mosquitos/métodos , Controle de Mosquitos/instrumentação
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