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1.
World J Diabetes ; 14(10): 1463-1477, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37970124

RESUMO

There is a recent increase in the worldwide prevalence of both obesity and diabetes. In this review we assessed insulin signaling, genetics, environment, lipid metabolism dysfunction and mitochondria as the major determinants in diabetes and to identify the potential mechanism of gut microbiota in diabetes diseases. We searched relevant articles, which have key information from laboratory experiments, epidemiological evidence, clinical trials, experimental models, meta-analysis and review articles, in PubMed, MEDLINE, EMBASE, Google scholars and Cochrane Controlled Trial Database. We selected 144 full-length articles that met our inclusion and exclusion criteria for complete assessment. We have briefly discussed these associations, challenges, and the need for further research to manage and treat diabetes more efficiently. Diabetes involves the complex network of physiological dysfunction that can be attributed to insulin signaling, genetics, environment, obesity, mitochondria and stress. In recent years, there are intriguing findings regarding gut microbiome as the important regulator of diabetes. Valid approaches are necessary for speeding medical advances but we should find a solution sooner given the burden of the metabolic disorder - What we need is a collaborative venture that may involve laboratories both in academia and industries for the scientific progress and its application for the diabetes control.

2.
3 Biotech ; 13(3): 87, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36816753

RESUMO

Alteration in lipid metabolism can result in fat accumulation in adipose tissues, which may lead to two most important human diseases, obesity and diabetes. A shift in lipid metabolism deregulates signaling pathways which regulates obesity and/or diabetes. In this study, we examined the components of insulin/ TGF-ß pathways and their genetic interaction with Krüppel-like transcription factors (KLFs). Their role in energy homeostasis were discussed. We separately created klf/daf genes double mutants by carrying out klfs RNAi on daf-2 (e1391), daf-4 (e1364), daf-7 (e1372); dpy-1 (e1), daf-14 (m77), daf-16 (mgDf50) mutants. And then conducted Oil O Red staining to assay the klf/daf RNAi worms for fat deposits and examine genetic interaction between klfs and daf genes. The results showed that worms bearing klf-1, 2, or 3 and daf-2, or daf-4 mutations deposit large, but similar fat levels as individual mutants. The results suggested that they target the same molecular pathway of fat storage. klf-1, 2 or 3 RNAi /daf-7 worms showed higher fat deposits in klf-1, 2, or 3 RNAi/daf-7 worms than klf-1, 2, or 3 RNAi or daf-7 mutants alone, which showed a functional interaction between klfs and daf-7 in perhaps TGF-ß-like pathway. Altogether our study suggests a direct role of klfs in insulin signaling pathway.

3.
Sci Rep ; 11(1): 14119, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34238977

RESUMO

Conventional larvicide delivery strategies originally developed for permanent and floodwater mosquitoes have proved suboptimal in the small, scattered, and cryptic larval habitats preferred by container-inhabiting Aedes mosquitoes. New methods such as autodissemination, wherein adult mosquitoes spread insecticides to their own larval habitats, have been under study. Another novel delivery method termed heterodissemination, i.e. larvicide delivery by other species sharing the same habitats, has also been proposed. We conducted a proof-of-concept study with four independent experiments using American bullfrogs (Lithobates catesbeianus) and green frogs Lithobates clamitans as carriers of pyriproxyfen, an insect growth regulator, under semi-field conditions in three different locations, two in New Jersey, and one in Utah. Frogs with attached slow-release pyriproxyfen tablets were introduced into outdoor enclosures with water containers. Water samples from the containers were periodically tested using larval Aedes albopictus and Culex pipiens mosquitoes to assess mortality and percent eclosure inhibition. Overall pupal mortality [95% credible intervals] estimated by Bayesian analysis for the treatment group was 73.4% [71.3-75.2] compared to 4.1% [2.9-5.5] for the control group. Mortality within treatment groups in four different experiments ranged from 41 to 100%, whereas control mortalities ranged from 0.5% to 11%. We conclude that heterodissemination is a promising and effective approach deserving of further study.


Assuntos
Culicidae/efeitos dos fármacos , Ecossistema , Inseticidas/toxicidade , Controle de Mosquitos , Vertebrados/parasitologia , Animais , Larva/efeitos dos fármacos , New Jersey , Pupa/efeitos dos fármacos , Utah
4.
Acta Trop ; 218: 105895, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33753028

RESUMO

Most artificial dietary systems for feeding mosquitoes require a membrane feeder, host cues, phosphate saline buffers and a phagostimulant. These multicomponent feeders are complex, expansive and cumbersome that requires fully trained personnel. The objective of the present is to develop a simple sugar assisted protein (SAP) diet for the egg production of Aedes albopictus. The present study assessed the potential use of SAP dietary system on the engorgement, fecundity, preference of diet components and production of multiple generations of Ae. albopictus. Our data show that the female mosquitoes have strongly preferred a diet with: (i) a combination of sugar and protein over the individual component, and (ii) water over PBS (phosphate buffered saline) buffer as a carrier, whereas adenosine triphosphate (ATP) was not required as a phagostimulant. Based on our optimization data, the SAP diets (10-20% bovine serum albumin in 5% sucrose aqueous solution) do not require chemo-attractive lure, phagostimulant ATP, temperature and membrane feeding components. Female mosquitoes readily engorge on SAP diets and show similar rates of survival and fecundity compared to those when blood-fed on live animals. In addition, the number of eggs produced by female mosquitoes fed on SAP diets kept consistent for 10 consecutive generations. Our results indicate that SAP diet is a potential alternative against blood feeding that is simple and cost-effective diets for Ae. albopictus colony maintenance and to support large scale mass- production for experimental and other purposes.


Assuntos
Aedes/crescimento & desenvolvimento , Aedes/metabolismo , Ração Animal , Métodos de Alimentação , Proteínas/administração & dosagem , Açúcares/administração & dosagem , Animais , Soluções Tampão , Dieta , Comportamento Alimentar , Feminino , Fertilidade , Masculino
5.
PLoS One ; 15(9): e0235548, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946475

RESUMO

We constructed an electric multi-rotor autonomous unmanned aerial system (UAS) to perform mosquito control activities. The UAS can be equipped with any of four modules for spraying larvicides, dropping larvicide tablets, spreading larvicide granules, and ultra-low volume spraying of adulticides. The larvicide module sprayed 124 µm drops at 591 mL/min over a 14 m swath for a total application rate of 1.6 L/ha. The tablet module was able to repeatedly deliver 40-gram larvicide tablets within 1.1 m of the target site. The granular spreader covered a 6 m swath and treated 0.76 ha in 13 min at an average rate of 1.8 kg/ha. The adulticide module produced 16 µm drops with an average deposition of 2.6 drops/mm2. UAS pesticide applications were made at rates prescribed for conventional aircraft, limited only by the payload capacity and flight time. Despite those limitations, this system can deliver pesticides with much greater precision than conventional aircraft, potentially reducing pesticide use. In smaller, congested environments or in programs with limited resources, UAS may be a preferable alternative to conventional aircraft.


Assuntos
Aeronaves , Culicidae , Monitorização de Parâmetros Ecológicos/instrumentação , Inseticidas/administração & dosagem , Controle de Mosquitos/instrumentação , Animais , Larva
6.
J Med Entomol ; 57(4): 1120-1130, 2020 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-32006427

RESUMO

Effective suppression of container-inhabiting Asian Tiger [Aedes albopictus (Skuse)] (Diptera: Culicidae) and yellow fever [Aedes aegypti (L.)] (Diptera: Culicidae) mosquitoes presents one of the most intractable problems for modern mosquito control. Traditional tools often fail to control populations of these mosquito species, and are prohibitively expensive or have negative environmental impacts. Novel approaches and tools are urgently needed for integrated container-inhabiting mosquito management programs. One of the most promising techniques is autodissemination. We present the results of a long-term large-scale study conducted in a temperate urbanized environment representing typical Ae. albopictus habitats. Three treatment sites with autodissemination stations and three nearby reference sites were monitored for eggs, immature, and adult mosquitoes over a period of 3 yr from 2014 to 2016. Elevated larval and pupal mortality of 12-19% on average was the most notable outcome in sentinel cups of the treatment sites. The number of eggs in the treatment sites was significantly reduced in 2014, but not in 2015 or 2016. Adult populations remained similar in treatment and reference sites throughout the study. The impact of autodissemination on mosquito populations was lower than reported by previous investigations. Technical and logistical problems associated with wider coverage and working in multiple urban neighborhoods contributed to reduced efficacy. Incorporating autodissemination with routine mosquito control operations and commercializing this methodology for general public use will require further research on combining this tool with other novel or conventional technologies.


Assuntos
Aedes , Inseticidas/administração & dosagem , Controle de Mosquitos/instrumentação , Piridinas/administração & dosagem , Animais , Feminino , Masculino , Controle de Mosquitos/métodos , Mosquitos Vetores , Óvulo , Pupa
7.
Pest Manag Sci ; 76(6): 2105-2112, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31951068

RESUMO

BACKGROUND: Management of Aedes albopictus and Ae. aegypti is challenging in large part due to the cryptic nature of their larval habitats. Autodissemination, using conspecific species to transfer pesticide, is unable to provide proactive control. Here we report results from a new hypothesis, heterodissemination, wherein females of the cohabiting non-biting midge, Chironomus decorus, reared in the laboratory, treated with pyriproxyfen, and released to transfer lethal concentrations to shared mosquito larval habitats. RESULTS: Pyriproxyfen-impregnated oil and powder formulations were developed. The average payload for each female midge treated with oil followed by powder formulations was 5.07 ± 0.92 µg of active ingredient or 1660 times the median lethal concentration (LC50 ) for Ae. albopictus or Ae. aegypti in 200 mL of water. Subsequent residue analysis showed pyriproxyfen transference from chironomids, treated with oil formulation only, into water-holding containers up to 2.06 ppb or 171.7 times the LC50 . Releasing 20 laboratory reared and contaminated Chironomus decorus into a small room resulted in 80.42 ± 0.67% and 75.67 ± 3.14% Ae. albopictus pupal mortality in open and cryptic sentinel ovicups, respectively. Container water volumes ranging up to 4 L did not affect efficacy. In a large field cage, 90.3 ± 2.5% Ae. albopictus mortality was resulted from releasing 100 treated female midges. Releasing 400 contaminated midges into a residential backyard resulted in 74.3% pupal mortality in sentinel ovicups. CONCLUSIONS: Room, large field cage and field release trials demonstrated that adult midges reared and treated in the laboratory transfer highly lethal concentrations of pyriproxyfen to Ae. albopictus container habitats. Heterodissemination provides a potential approach for precision, proactive mosquito control, which may draw attention for further studies. © 2020 Society of Chemical Industry.


Assuntos
Aedes , Chironomidae , Animais , Feminino , Hormônios Juvenis , Larva , Controle de Mosquitos , Pupa
8.
J Invertebr Pathol ; 168: 107273, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31672506

RESUMO

We examined manipulation of mosquito behavior by the parasitic mermithid nematode, Strelkovimermis spiculatus. This nematode species typically infects early instar host larvae and emerges after parasitic development to kill last-instar larvae. Parasitized adults, however, have occasionally been reported from field collections. We obtained low rates (1.7-11.5%) of parasitized adults in laboratory exposures only when Culex pipiens pipiens fourth-instar larvae nearing pupation were exposed to infective nematodes. This did not allow an adequate interval for parasitic development in immature host stages. Parasitized adult females in a multiple-choice assay were three times more likely to seek water than a blood source (63.1 vs. 20.5%), whereas uninfected females were twice as likely to seek blood than water (64%3.9 vs. 32.6%). This altered host behavior benefits the parasite by providing the only mechanism for dispersal and colonization of new host habitats while concurrently avoiding risks from the defensive behaviors associated with blood-feeding. Behavioral alternation in Cx. p. pipiens larval hosts was also examined using larvae infected as second instars to allow for a normal duration of parasitic development. As larvae neared pupation and parasite emergence, parasitized larvae became more spatially aggregated than unparasitized larvae. This altered host behavior benefits the parasite by providing a corresponding increase in post-parasite aggregation, which facilitates formation of large mating clusters and concomitantly reproductive success. Parasites derive fitness gains by overriding host autonomy, whereas hosts have zero fitness once parasitism is established, suggesting a coevolutionary response is inoperative and that the behavioral modifications may be adaptive.


Assuntos
Culex/parasitologia , Mermithoidea/fisiologia , Distribuição Animal , Animais , Comportamento Alimentar , Interações Hospedeiro-Parasita , Larva/parasitologia
9.
J Econ Entomol ; 112(3): 1337-1342, 2019 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-30768177

RESUMO

Barrier applications, treating vegetation and other potential mosquito resting areas with residual pesticides, have become standard practice for commercial pest management professionals offering mosquito control services. These treatments are generally effective in reducing numbers of the Asian tiger mosquito, Aedes albopictus (Skuse). In the temperate climates, adult Ae. albopictus populations are naturally eliminated each winter and must be grown from diapausing eggs the following spring. Therefore, early-season control interventions timed before populations rebound may further reduce population growth compared with interventions that take place after the population has peaked. We compared Early (1 June) barrier applications of lambda-cyhalothrin (Demand CS) mixed with the insect growth regulator pyriproxyfen (Archer IGR) to Late applications (31 July) in urban and suburban residential parcels in New Jersey. These applications resulted in 43 and 51% reductions in adult Ae. albopictus populations in the Early and Late intervention study parcels, respectively, when compared with the untreated Controls. Indirect applications of pyriproxyfen (i.e., rainwater runoff transferring pesticide) to potential larval habitat did not cause mortality in laboratory larval bioassays but direct mist applications of the Archer and Demand combination to larval habitats led to elevated larval mortality over a 6-wk period. The Early-season intervention offered no advantage in efficacy on adult populations compared with the Late-season intervention, which targeted peak mosquito populations. Our study provides support for the efficacy of barrier applications and illustrates the importance of timing barrier treatments to coincide with established Ae. albopictus action thresholds.


Assuntos
Aedes , Piretrinas , Animais , Controle de Mosquitos , New Jersey , Nitrilas , Piridinas
10.
Clin Nutr ; 38(5): 1971-1985, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30446179

RESUMO

BACKGROUND: Dietary salts sodium (Na+), potassium (K+), magnesium (Mg2+), and calcium (Ca2+) are important in metabolic diseases. Yet, we do not have sufficient understanding on the salts global molecular network in these diseases. In this systematic review we have pooled information to identify the general effect of salts on obesity, insulin resistance and hypertension. AIMS: To assess the roles of salts in metabolic disorders by focusing on their individual effect and the network effect among these salts. METHODS: We searched articles in PubMed, EMBASE and Google Scholar. We selected original laboratory research, systematic reviews, clinical trials, observational studies and epidemiological data that focused on dietary salts and followed the preferred reporting items for systematic review in designing the present systematic review. RESULTS: From the initial search of 2898 studies we selected a total of 199 articles that met our inclusion criteria and data extraction. Alterations in metabolic pathways associated with the sensitivity of sodium, potassium, magnesium and calcium may lead to obesity, hypertension, and insulin resistance. We found that the results of most laboratory research, animal studies and clinical trials are coherent but some research outcome are either inconsistent or inconclusive. CONCLUSION: Important of salts in metabolic disorder is evident. In order to assess the effects of dietary salts in metablic diseases, environmental factors, dietary habits, physical activity, and the microbiome, should be considered in any study. Although interest in this area of research continues to grow, the challenge is to integrate the action of these salts in metabolic syndrom.


Assuntos
Metabolismo Energético/fisiologia , Síndrome Metabólica , Cloreto de Sódio na Dieta/metabolismo , Animais , Cálcio da Dieta/metabolismo , Humanos , Insulina/metabolismo , Magnésio/metabolismo , Síndrome Metabólica/metabolismo , Síndrome Metabólica/fisiopatologia , Potássio/metabolismo
11.
Pest Manag Sci ; 75(4): 1115-1122, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30280488

RESUMO

BACKGROUND: Given the lack of vaccines for most vector-borne diseases, vector control is often the primary option for disease control. Aedes albopictus are difficult to control because the immatures primarily develop in containers ubiquitous in residential properties. Conventional adulticide campaigns often result in brief, rebounding population declines, so incorporating new techniques into an integrated pest management program is imperative. We performed combined area-wide applications of the larvicides Bacillus thuringiensis var. israelensis and pyriproxyfen with the adulticide sumithrin and prallethrin to achieve extended suppression of Ae. albopictus populations in Trenton, NJ, USA. We deployed bioassay cups to assess the spatial penetration and efficacy of the applications. RESULTS: Inhibition of adult emergence was significantly higher in the treatment bioassay cups than in laboratory controls (z = 4.65, P < 0.0001) and field control bioassay cups (z = 8.93, P < 0.0001). We observed a lower trend in adult numbers following season-long combined application of pyriproxyfen and adulticide, with numbers of adult Ae. albopictus at the treatment site up to five times lower than at the control site. CONCLUSION: Pyriproxyfen is a powerful mosquito larvicide and pupacide with low mammalian toxicity that shows promise for area-wide vehicle-mounted (either ground or airborne) applications. © 2018 Society of Chemical Industry.


Assuntos
Aedes , Bacillus thuringiensis/química , Inseticidas , Controle de Mosquitos , Piretrinas , Piridinas , Aedes/crescimento & desenvolvimento , Animais , Larva/crescimento & desenvolvimento , Controle de Mosquitos/instrumentação , New Jersey
12.
Pest Manag Sci ; 74(4): 885-895, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29087613

RESUMO

BACKGROUND: Control of the container-inhabiting mosquito, Aedes albopictus, is difficult using conventional methods due to its selection of cryptic peri-domestic habitats. We evaluated whether autodissemination stations can deliver sufficient pyriproxyfen to sentinel containers to produce significant pupal mortality in different habitats such as competing oviposition sites, peri-domestic habitats, junkyards and tire piles. We also tested how far the pesticide could be transferred over a 200-m range. RESULTS: Autodissemination stations performed effectively for 8-12 weeks under field conditions. Pupal mortality was reduced in sentinel cups with high-competing oviposition habitats (5 versus 20) in isolated plots; however, similar results were not seen in residential areas. Increasing the number of stations per plot (from 1 to 4) enhanced the efficacy. Peri-domestic habitat trials showed the highest pupal mortality (50.4%) and site contamination with pyriproxyfen (82.2%) among the trials. Autodissemination stations were able to contaminate habitats in a junkyard (50.0%) and tire piles (40.2%). Pyriproxyfen was detected in sentinel cups up to 200 m from stations. Detection of pyriproxyfen by residue analysis (0.005-0.741 µg L-1 ) in field samples confirmed the transfer of the insect growth regulator. CONCLUSION: Autodissemination stations have shown promising potential as a novel pest management tool against container mosquitoes in field trials in different habitats confronted by mosquito control personnel. © 2017 Society of Chemical Industry.


Assuntos
Aedes , Ecossistema , Inseticidas , Controle de Mosquitos , Piridinas , Aedes/crescimento & desenvolvimento , Animais , Controle de Mosquitos/métodos , New Jersey , Pupa/crescimento & desenvolvimento , Estações do Ano
13.
J Med Entomol ; 55(2): 472-476, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29244157

RESUMO

Mosquito control programs in the United States are still searching for best management practices to control the Asian tiger mosquito, Aedes albopictus (Skuse; Diptera: Culicidae). Most intervention methods for this species are either labor intensive (e.g., source reduction) or short-term (e.g., ultra-low-volume adulticiding). We investigated the effectiveness of barrier spray pesticide applications within urban and suburban residential yards in New Jersey as a control strategy using a before-after-control-impact (BACI) approach. Applications of Demand CSR pyrethroid (9.7% AI lambda-cyhalothrin) only or combined Demand CSR and Archer IGR insect growth regulator (1.3% AI pyriproxyfen) applications resulted in significant and similar decreases in adult mosquito abundance post-treatment ranging from 78 to 74% respectively, compared with the untreated control. Both insecticides exceeded the 70% reduction threshold considered as effective for Ae. albopictus control for 2 to 4 wk. However, applications of Archer IGR alone did not reduce adult mosquito abundance. The field study results were supported by laboratory no-choice bioassays using treated leaf foliage. Our study is the first data driven evidence of the residual efficacy of barrier pesticide applications in New Jersey with lambda-cyhalothrin that provided significant reductions in adult Ae. albopictus populations for an extended duration.


Assuntos
Aedes , Inseticidas , Controle de Mosquitos/métodos , Nitrilas , Piretrinas , Piridinas , Animais , Cidades , Feminino , Larva , Masculino , New Jersey
14.
J Nematol ; 49(3): 316-320, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29062155

RESUMO

Superparasitism is a common phenomenon in mosquito-parasitic mermithid nematodes. Multiple nematodes are needed in a single host to produce males. Host selection behavior and intraspecific competition among Romanomermis iyengari and Strelkovimermis spiculatus were investigated against their host, Culex pipiens pipiens in laboratory experiments. In a choice assay between previously infected and uninfected host larvae, infectious preparasites of both nematode species could distinguish not only between infected and uninfected hosts, but even between different parasite loads in showing a strong preference for uninfected hosts or hosts with a low parasite load. Host heart rate declined briefly immediately after parasitism. Superparasitism resulted in increased parasite mortality. Scramble competition within mosquito larvae for limited host nutrients, coupled with a skewed sex ratio favoring males, is assumed to lead to parasite population decline and subsequently toward host-parasite population equilibrium. The ability of mermithid preparasites to accurately assess parasite load likely plays an important role in host population dynamics and regulation.

15.
J Invertebr Pathol ; 146: 53-57, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28433568

RESUMO

The mosquito-parasitic nematode, Strelkovimermis spiculatus (Mermithidae: Nematoda) emerges from hosts and aggregates to form mating clusters characterized by intense male-male competition for females. Successful males deposit an adhesive copulatory plug over the female vulva after insemination. In choice experiments, males strongly preferred virgin females, whereas plugged females were ignored. Males made no attempt to displace copulatory plugs deposited by previous males. Plugged females repelled males without the need for physical contact. The observed chemical repellency was independent of females, since excised plugs alone showed the same negative male response. Removal of the plug shortly after mating reduced fecundity by 90%, presumably due to spermatids leaking from the vulva. The plug as a nutritional gift hypothesis was rejected because there was no post-mating reduction in plug size that would have indicated absorption. Despite being a male adaption to sperm competition, we conclude that the copulatory plug serves the fitness needs of both males and females in multiple roles that include paternity preservation, reduced male harassment, improved male search for mates, increased fecundity, and sperm retention.


Assuntos
Copulação/fisiologia , Nematoides/fisiologia , Animais , Feminino , Masculino , Reprodução
16.
Parasit Vectors ; 10(1): 139, 2017 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-28279191

RESUMO

BACKGROUND: Aedes albopictus, the Asian tiger mosquito, is an aggressive, highly anthropophilic, day-biting mosquito with an expanding geographic range. Suppression of Ae. albopictus is difficult because of the abundance and prevalence of larval habitats within peridomestic environments, particularly cryptic habitats such as corrugated extension spouts, fence post openings, discarded food containers, etc. Because of the challenges of eliminating or treating larval habitats of this species, we tested an autodissemination concept to contaminate these habitats with the insect growth regulator pyriproxyfen. METHODS: Our study was conducted in the City of Trenton (Mercer County), New Jersey, USA (40°12'N, 74°44'W). We selected six hot spots, where five or more Ae. albopictus males or females were collected based on weekly trap surveillance. A trapping unit was a city block, approximately 0.8 ha (hot spot), where we deployed 26 to 28 autodissemination stations per treatment plot. To gauge efficacy, we deployed BGS traps, oviposition cups, and sentinel cups in treatment and control locations. RESULTS: We found a significant reduction in eggs (P < 0.0001) and larval populations (P < 0.0001) as a result of treatment. Pupal mortality, as determined through bioassays, was also significantly higher in the treatment sites (P < 0.0001). CONCLUSION: Our results clearly show the potential and unique use of the autodissemination stations to control immature Ae. albopictus in urban areas. Penetration of larvicides with existing methods are difficult to reach cryptic habitats, but the autodissemination approach, which exploits the oviposition behavior of the target pest, can be integrated into intervention programs. New tools are urgently needed to curb the expansion and public health implications of Ae. albopictus and other container-inhabiting species.


Assuntos
Aedes/efeitos dos fármacos , Inseticidas/farmacologia , Controle de Mosquitos/métodos , Piridinas/farmacologia , Animais , Feminino , Inseticidas/administração & dosagem , Larva , Masculino , Oviposição , Óvulo , Pós , Pupa , Piridinas/administração & dosagem
17.
Nutr Metab (Lond) ; 14: 22, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28261316

RESUMO

BACKGROUND: Dietary salts are important factors in metabolic disorders. They are vital components of enzymes, vitamins, hormones, and signal transduction that act synergistically to regulate lipid metabolism. Our previous studies have identified that Krüppel-like factor -3 (KLF-3) is an essential regulator of lipid metabolism. However, it is not known if KLF-2 also regulates lipid metabolism and whether KLF-2 and -3 mediate the effects of dietary salts on lipid metabolism. METHODS: In this study, we used klf mutants [homozygous klf-2 (ok1043) V and klf-3 (ok1975) II mutants] to investigate the role of dietary salts in lipid metabolism. All gene expression was quantified by qRT-PCR. Localization of KLF-2 was analyzed by the expression of klf-2::gfp (in pPD95.75 vector) using a fluorescent microscope. Fat storage was measured by Oil Red O staining. RESULTS: Klf-2 was identified to express in the intestine during all stages of Caenorhabditis elegans development with peak expression at L3 stage. Mutation of klf-2 increased fat accumulation. Under regular growth media free of Ca2+, the expression of both klf-2 and -3 was inhibited slightly; further their expression reduced significantly in WT worms fed on 10X Ca2+ diet. When klf-3 was mutated, the expression of klf-2 increased under 10X Ca2+ diet; but when klf-2 was mutated, the expression of klf-3 was not altered under 10X Ca2+ diet. Overall, Mg2+ and K+ were less effective on the gene expression of klfs. KLF target gene Ce-C/EBP-2 showed elevated expression in WT and klf-3 (ok1975) worms with changed Ca2+ concentrations but not in klf-2 (ok1043) worms. However, high Ca+2 diet exhibited inhibitory effect on Ce-SREBP expression in WT worms. CONCLUSION: Dietary Ca2+ is most effective on fat storage and klf-2 expression, wherein high Ca2+ diet decreased klf-2 expression and reduced fat buildup. Mechanistic study identified Ce-C/EBP (C48E7.3; lpd-2) and Ce-SREBP (Y47D3B.7; lpd-1) as the target genes of klf-2 and/or klf-3 to mediate lipid metabolism. This study identifies a new function of klf-2 in inhibiting fat buildup and reveals the interplay between dietary salts and klf-2 and klf-3 in lipid metabolism.

18.
PLoS Negl Trop Dis ; 10(12): e0005235, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-28033379

RESUMO

BACKGROUND: The Asian tiger mosquito, Aedes albopictus, is a vector of dengue, Chikungunya, and Zika viruses. This mosquito inhabits a wide range of artificial water-holding containers in urban and suburban areas making it difficult to control. We tested the hypothesis that female-driven autodissemination of an insect growth regulator could penetrate cryptic oviposition habitats difficult to treat with conventional insecticidal sprays. METHODOLOGY: Oviposition preferences of Ae. albopictus females for open and cryptic cups were tested in semi-field experiments. Two conventional larvicidal sprayers were tested to determine droplet penetration and larvicidal efficacy in open and cryptic habitats using Bacillus thuringiensis var. israelensis (Bti) in the field. Finally, the efficacy of pyriproxyfen autodissemination stations was assessed in cryptic and open cups in residential areas during 2013 and 2014. PRINCIPAL FINDINGS: Gravid females strongly preferred cryptic (53.1±12.9 eggs/cup) over open (10.3±4.3 eggs/cup) cups for oviposition. Cryptic cups showed limited droplet penetration and produced 0.1-0.3% larval mortality with a conventional backpack and low-volume sprays of Bti. The autodissemination stations effectively contaminated these cryptic cups (59.3-84.6%) and produced 29.7-40.8% pupal mortality during 2013-2014. Significant pupal mortality was also observed in open cups. CONCLUSIONS: The autodissemination station effectively exploits the oviposition behavior of wild gravid females to deliver pyriproxyfen to targeted oviposition habitats. Although the pupal mortality in cryptic cups was relatively lower than expected for the effective vector control. Autodissemination approach may be a suitable supporting tool to manage Ae. albopictus immatures in the cryptic habitats those are less accessible to conventional larvicidal sprays.


Assuntos
Aedes/efeitos dos fármacos , Inseticidas , Hormônios Juvenis/farmacologia , Controle de Mosquitos/métodos , Oviposição/efeitos dos fármacos , Piridinas/farmacologia , Animais , Bacillus thuringiensis , Ecossistema , Feminino , Larva/efeitos dos fármacos , Masculino , Pupa/efeitos dos fármacos
19.
PLoS One ; 11(4): e0152069, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27116103

RESUMO

Adult control of Aedes albopictus via ultra-low volume is difficult because this species occurs primarily in peridomestic habitats where obstacles such as buildings and vegetation can disrupt spray plumes and droplet dispersion. We determined droplet penetration and characterization of a pyrethroid adulticide applied from the ground at mid (46.77 ml/ha) and maximum (93.53 ml/ha) label rates within cryptic habitats of urban and suburban environments. Droplets were collected from all habitats, with no significant differences detected between locations within the same application rate or collection method. No differences were detected in droplet densities (drops per mm2) between rates within urban environments, but more droplets were collected in urban (149.93 ± 11.07 SE) than suburban sites (114.37 ± 11.32) at the maximum label rate (P = 0.003). The excellent penetration of aerosols into cryptic habitats of an urban site was likely due to the shorter spray paths afforded by our network of roads and alleys. Mid label rates displayed similar droplet density values as maximum label rates in urban areas, indicating that lower rates may be used effectively to reduce costs, lessen non-target effects, and increase environmental stewardship. Advances in formulations and technology are driving changes in adulticide applications, leading to use of the minimum effective dose for maximum efficacy, precision, and accountability.


Assuntos
Aedes , Inseticidas/administração & dosagem , Controle de Mosquitos/métodos , Aerossóis , Animais , Meio Ambiente , Humanos , Insetos Vetores , Conceitos Meteorológicos , New England , Piretrinas/administração & dosagem , Saúde Suburbana , Saúde da População Urbana
20.
J Med Entomol ; 52(3): 308-14, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26334803

RESUMO

Sugar availability varies greatly in nature, and determining how this affects male mosquito fitness is essential for understanding population dynamics. We allowed male Aedes albopictus (Skuse) carbohydrate access for increasing intervals of time immediately after eclosion and we evaluated their fitness by comparing mortality, mating success, and sperm transfer. We compared individual male Ae. albopictus, which were offered water or 20% sucrose solution for 24, 48, or 72 h. As predicted, there were significant increases in fitness for each additional day of sucrose access. Following sugar exposure, we allowed males daily access to three virgin females. We assessed mating success through observation of spermatozoa in the female spermathecae. When individuals of the same age were compared, males with sugar access exhibited significantly greater mating success than water-treated males in all treatments. The total number of spermathecae filled by males with sugar access in the 48- and 72-h treatments was also significantly greater on some days; these were 3-5 d posteclosion in the 48-h treatment and 5-6 d posteclosion in the 72-h treatment. We conclude that extended sugar access at eclosion is important for maximizing fitness in male Ae. albopictus and should be applicable to sterile male release efforts, especially when laboratory-reared males suffered from other disadvantages. We recommend retaining adult males for 3 d posteclosion prior to release to improve their mating success in male release initiatives.


Assuntos
Aedes/fisiologia , Metabolismo dos Carboidratos , Comportamento Sexual Animal , Aedes/genética , Animais , Privação de Alimentos , Aptidão Genética , Masculino
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