scholarly journals LABORATORY EVALUATION OF THE DEVELOPMENT OF Aedes aegypti IN TWO SEASONS: INFLUENCE OF DIFFERENT PLACES AND DIFFERENT DENSITIES

2014 ◽  
Vol 56 (5) ◽  
pp. 369-374 ◽  
Author(s):  
Tatiana Forte Lopes ◽  
Marcia Moreira Holcman ◽  
Gerson Laurindo Barbosa ◽  
Maria de Fatima Domingos ◽  
Rosa Maria Oliveira Veiga Barreiros
Keyword(s):  
Aedes Aegypti ◽  
Water Temperature ◽  
Median Time ◽  
Time Development ◽  
Laboratory Evaluation ◽  
Southeastern Brazil ◽  
Survival Curves ◽  
Coastal City ◽  
Individual Experiment ◽  
The Individual

Aedes aegypti is an important vector in Brazil being the main vector of the dengue-fever. This paper employs survival curves to describe the time in days from larvae to adult forms of Aedes aegypti raised, individually and collectively, and compares it during winter and spring when positioned inside and outside a laboratory. The study was conducted in São Vicente, a coastal city in Southeastern Brazil. The lowest water temperature in winter and in spring was 20 °C and the highest was 26 °C in spring. Higher and more stable temperatures were measured in the intra compared to the peri in both seasons. Consequently, larvae positioned in the intra resulted in the lowest median time to develop in the individual and collective experiment (nine and ten days, respectively). At least 25% of the larvae positioned in the intra in the individual experiment in the spring took only seven days to reach adulthood. Sex ratios and the median time development by sex did not show significant differences. These results indicate that efforts to control Aedes aegypti must be continuous and directed mainly to prevent the intra-domiciliary sites that can be infested in a week in order to reduce the human-vector contact.

Laboratory Evaluation of Susceptibility of Natural Subpopulations of Aedes aegypti Larvae to Temephos

2006 ◽  
Vol 22 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Priscila A. Biber ◽  
Juan Rondan Dueñas ◽  
Francisco Ludueña Almeida ◽  
Cristina N. Gardenal ◽  
Walter R. Almirón
Keyword(s):  
Aedes Aegypti ◽  
Laboratory Evaluation

Laboratory evaluation of Dalbergia oliveri (Fabaceae: Fabales) extracts and isolated isoflavonoids on Aedes aegypti (Diptera: Culicidae) mosquitoes

2013 ◽  
Vol 44 ◽  
pp. 653-658 ◽  
Author(s):  
Sujittra Pluempanupat ◽  
Nutchaya Kumrungsee ◽  
Wanchai Pluempanupat ◽  
Kotchamon Ngamkitpinyo ◽  
Warinthorn Chavasiri ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Laboratory Evaluation

Octopamine Modulates the Sensitivity of Limulus Ventral Photoreceptor

1984 ◽  
Vol 39 (9-10) ◽  
pp. 981-985 ◽  
Author(s):  
H. Stieve ◽  
E. André
Keyword(s):  
Receptor Potential ◽  
Individual Experiment ◽  
The Individual

Abstract The effect of extracellularly applied octopamine (10-5mol/l) on the receptor potential of the Limulus ventral photoreceptor was studied. Octopamine increases the sensitivity of the photoreceptor in the light-adapted state more than in the dark-adapted state. Extracellular application of phentolamine (10-5mol/l) has an opposite, antagonizing effect. The octopamine effect, though reproducible in the individual experiment, varies greatly from preparation to preparation.

The accumulation of radioactive cesium, phosphorus, strontium, and yttrium by mosquito larvae and its relevance to radiation dose

1972 ◽  
Vol 50 (6) ◽  
pp. 767-770
Author(s):  
A. G. Scott ◽  
J. E. Guthrie
Keyword(s):  
Radiation Dose ◽  
Aedes Aegypti ◽  
Dose Rate ◽  
Radioactive Cesium ◽  
Mosquito Larvae ◽  
Radionuclide Concentration ◽  
Internal Radiation ◽  
Stage Of Development ◽  
Apparent Concentration ◽  
The Individual

Aedes aegypti (L.) larvae were reared in solutions of 137Cs, 32P, and 90Sr + 90Y and the apparent concentration ratios of the individual radionuclides which were accumulated are reported. A consideration of the significance of accumulation to the internal radiation dose delivered to the larvae reveals that larvae reared in identical concentrations of a radionuclide did not receive the same dose, nor were they exposed to the greatest dose-rate at the same stage of development. The probable dose to larvae reared in radioactive solutions cannot be calculated solely from a knowledge of the radionuclide concentration in the rearing medium.

scholarly journals Effects of Sunlight Exposure on Grapevine Powdery Mildew Development

2012 ◽  
Vol 102 (9) ◽  
pp. 857-866 ◽  
Author(s):  
Craig N. Austin ◽  
Wayne F. Wilcox
Keyword(s):  
Powdery Mildew ◽  
Solar Radiation ◽  
Controlled Environment ◽  
Disease Development ◽  
Inhibitory Effects ◽  
Grapevine Powdery Mildew ◽  
Individual Experiment ◽  
Hyphal Formation ◽  
The Individual ◽  
Artificial Shading

Natural and artificially induced shade increased grapevine powdery mildew (Erysiphe necator) severity in the vineyard, with foliar disease severity 49 to 75% higher relative to leaves in full sun, depending on the level of natural shading experienced and the individual experiment. Cluster disease severities increased by 20 to 40% relative to those on check vines when ultraviolet (UV) radiation was filtered from sunlight reaching vines in artificial shading experiments. Surface temperatures of leaves in full sunlight averaged 5 to 8°C higher than those in natural shade, and in one experiment, filtering 80% of all wavelengths of solar radiation, including longer wavelengths responsible for heating irradiated tissues, increased disease more than filtering UV alone. In controlled environment experiments, UV-B radiation reduced germination of E. necator conidia and inhibited both colony establishment (hyphal formation and elongation) and maturity (latent period). Inhibitory effects of UV-B radiation were significantly greater at 30°C than at 20 or 25°C. Thus, sunlight appears to inhibit powdery mildew development through at least two mechanisms, i.e., (i) UV radiation's damaging effects on exposed conidia and thalli of the pathogen; and (ii) elevating temperatures of irradiated tissues to a level supraoptimal or inhibitory for pathogen development. Furthermore, these effects are synergistic at temperatures near the upper threshold for disease development.

Laboratory Evaluation of Larvicidal and Oviposition Deterrent Properties of Edible Plant Oils for Potential Management of Aedes aegypti (Diptera: Culicidae) in Drinking Water Containers

2019 ◽  
Vol 56 (4) ◽  
pp. 1055-1063
Author(s):  
Teresia M Njoroge ◽  
May R Berenbaum
Keyword(s):  
Linoleic Acid ◽  
Aedes Aegypti ◽  
Acid Content ◽  
Edible Oils ◽  
Linoleic Acid Content ◽  
Laboratory Evaluation ◽  
Plant Oils ◽  
Edible Plant ◽  
Oviposition Deterrents ◽  
Olive Oils

Abstract The yellow fever mosquito, Aedes aegypti (Diptera: Culicidae) transmits several devastating arboviruses, including dengue, chikungunya, and Zika virus, making development of inexpensive and eco-friendly strategies for its control an urgent priority. We evaluated the lethality of 13 commonly used plant-derived edible oils against late-third instar Ae. aegypti and then tested the three most lethal oils for stage-specific differences in lethality. We also examined the effects of the most lethal (hempseed), moderately lethal (sunflower and peanut), and least lethal (olive) oils on survival to adulthood and oviposition behavior of gravid females. We hypothesized that the insecticidal activity of edible oils is a function of the content of their linoleic acid, a key fatty acid component with film-forming properties. Among the 13 oils tested, hempseed oil was the most lethal, with an LC50 of 348.25 ppm, followed by sesame (670.44 ppm) and pumpkinseed (826.91 ppm) oils. Oils with higher linoleic acid content were more lethal to larvae than those with low linoleic acid content. Furthermore, pure concentrated linoleic acid was more lethal to larvae compared to any edible oil. In comparison to early instars, late instars were more susceptible to hempseed, sunflower, peanut, and olive oils; these oils also acted as oviposition deterrents, with effective repellency ≥63%. The proportion of larvae surviving to adulthood was significantly reduced in hempseed, sunflower, peanut, and olive oil treatments relative to controls. Our results suggest that some edible plant oils have potential as effective, eco-friendly larvicides, and oviposition deterrents for controlling container-dwelling mosquitoes, especially in resource-limited settings.

scholarly journals Predictive Thermal Inactivation Model for Effects of Temperature, Sodium Lactate, NaCl, and Sodium Pyrophosphate on Salmonella Serotypes in Ground Beef

2003 ◽  
Vol 69 (9) ◽  
pp. 5138-5156 ◽  
Author(s):  
Vijay K. Juneja ◽  
Harry M. Marks ◽  
Tim Mohr
Keyword(s):  
Heat Resistance ◽  
Survival Data ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Sodium Lactate ◽  
Sodium Pyrophosphate ◽  
Relative Reduction ◽  
Survival Curves ◽  
The Times ◽  
The Individual

ABSTRACT Analyses of survival data of a mixture of Salmonella spp. at fixed temperatures between 55°C (131°F) and 71.1°C (160°F) in ground beef matrices containing concentrations of salt between 0 and 4.5%, concentrations of sodium pyrophosphate (SPP) between 0 and 0.5%, and concentrations of sodium lactate (NaL) between 0 and 4.5% indicated that heat resistance of Salmonella increases with increasing levels of SPP and salt, except that, for salt, for larger lethalities close to 6.5, the effect of salt was evident only at low temperatures (<64°C). NaL did not seem to affect the heat resistance of Salmonella as much as the effects induced by the other variables studied. An omnibus model for predicting the lethality for given times and temperatures for ground beef matrices within the range studied was developed that reflects the convex survival curves that were observed. However, the standard errors of the predicted lethalities from this models are large, so consequently, a model, specific for predicting the times needed to obtained a lethality of 6.5 log10, was developed, using estimated results of times derived from the individual survival curves. For the latter model, the coefficient of variation (CV) of predicted times range from about 6 to 25%. For example, at 60°C, when increasing the concentration of salt from 0 to 4.5%, and assuming that the concentration of SPP is 0%, the time to reach a 6.5-log10 relative reduction is predicted to increase from 20 min (CV = 11%) to 48 min (CV = 15%), a 2.4 factor (CV = 19%). At 71.1°C (160°F) the model predicts that more than 0.5 min is needed to achieve a 6.5-log10 relative reduction.

Low-dose dexamethasone and thalidomide with higher frequency zoledronic acid (dtZ) for newly diagnosed multiple myeloma

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 18506-18506
Author(s):  
G. Teoh ◽  
D. Tan ◽  
C. Chuah ◽  
W. Hwang ◽  
R. Yiu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Zoledronic Acid ◽  
Complete Remission ◽  
Median Time ◽  
Low Dose ◽  
Dental Treatment ◽  
Osteonecrosis Of The Jaw ◽  
Newly Diagnosed ◽  
Grade 3 ◽  
The Individual

18506 Background: Although dexamethasone (Dex), thalidomide (Thal) and zoledronic acid (Zol) have frequently been combined for the treatment of multiple myeloma (MM), the ideal dosing schedule is unknown. We previously reported that lower doses of Dex and Thal can be effectively combined with high-frequency dosing of Zol (Haematologica 2005). Methods: This “dtZ” regimen - which comprises weekly Dex 20 mg OM for 4 days, Thal 50 mg ON, and 3-weekly Zol 4 mg - resulted in an impressive response rate (RR) of 61.6% and near complete remission (nCR)/complete remission (CR) rate of 7.7% in 26 patients with relapsed/refractory MM. Results: In this present study, we treated 22 newly diagnosed MM patients with “dtZ” and report an even more impressive RR of 100.0% and nCR/CR rate of 20–35%. The median time to response was 1.8 months and median time to maximum response was 2.2 months. The median time to progression (TTP) has not been achieved yet. As expected, low-dose Dex/Thal resulted in lower (18.1%) grade 3 or 4 toxicities. These were all infections; which lead to further dose-reduction of Dex. There were no thromboembolic events, despite the fact that aspirin was not routinely given. Of particular interest, 3- weekly Zol was not associated with any significant decrease in renal function, and none of our patients developed osteonecrosis of the jaw (ONJ). In fact, at the time of writing of this abstract, more than 1,000 doses of Zol had been administered in a 3-weekly fashion to these as well as other patients, and only 1 patient developed ONJ. This patient who had already received greater than 20 doses of Zol healed uneventfully after receiving appropriate outpatient dental treatment, and subsequently received another 8 doses of Zol with no recurrence of ONJ. Conclusion: In conclusion, the Zol-based “dtZ” regimen is potentially a highly-effective and safe frontline regimen for MM. Using Zol every 3 weeks with lower doses of Dex and Thal does not appear to increase the rate or severity of nephrotoxicity or ONJ. Although we do not know exactly why every patient responded to “dtZ”, we speculate that this could be due to a critical balance that has been achieved between the anti-MM, anti-osteoclastic and immunostimulatory effects of the individual drugs of the combination. No significant financial relationships to disclose.

scholarly journals Superposition of survival curves as a tool for epistasis analysis of longevity interventions

2017 ◽  
Author(s):  
Stefan Nowak ◽  
Johannes Neidhart ◽  
Jonas Rzezonka ◽  
Ivan G. Szendro ◽  
Rahul Marathe ◽  
...  
Keyword(s):  
Survival Curve ◽  
Null Model ◽  
Published Data ◽  
Survival Curves ◽  
Standard Analysis ◽  
Data Set ◽  
Epistasis Analysis ◽  
The Individual ◽  
Superposition Principles ◽  
Standing Problem

A long-standing problem in ageing research is to understand how different factors contributing to longevity should be expected to act in combination under the assumption that they are independent. Standard epistasis analysis compares the extension of mean lifespan achieved by a combination of interventions to the prediction under an additive or multiplicative null model, but neither model is fundamentally justified. Moreover, the target of longevity interventions is not mean life span but the entire survival curve. Here we formulate superposition principles that predict the survival curve resulting from a combination of two interventions based on the survival curves of the individual treatments, and quantify epistasis as the deviation from this prediction. We test the method on a published data set comprising survival curves for all combinations of 4 different longevity interventions in Caenorhabditis elegans. We find that epistasis is generally weak even when the standard analysis indicates otherwise.

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