scholarly journals Temperature changes alter the acute toxicity responses of cypermethrin in Zebrafish

2018 ◽  
Vol 29 (1) ◽  
pp. 64-70 ◽  
Author(s):  
MH Uddin ◽  
MS Alim ◽  
SMM Islam ◽  
H Rashid ◽  
M Shahjahan
Keyword(s):  
Blood Glucose ◽  
Acute Toxicity ◽  
Probit Analysis ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Temperature Regimes ◽  
Higher Temperature ◽  
T1 And T2 ◽  
Increasing Temperature ◽  
The Impact

The study was carried out to determine the effect of temperature changes on acute toxicity of pyrethroid pesticide cypermethrin in zebrafish. A two-day renewal bioassay system for 96h was conducted to find out LC50 value of cypermethrin at two temperature regimes i.e. 25°C and 30°C considering as T1 and T2, respectively. During the determination of LC50 in both temperatures, blood glucose (mg/dL) levels were measured at lower concentration (0.25 µg/L) of cypermethrin. The results of acute toxicity test at 96h LC50 values were calculated through probit analysis. It was found that 96h LC50 for T1 and T2 groups were about 2.1 and 1.4 µg/L, respectively. Significantly lower LC50 of cypermethrin at T2 compared to T1 showed that higher temperature increased the toxicity of cypermethrin. There was a significant increase (P<0.05) in blood glucose level (mg/dL) in 0.25 µg/L compared to 0 µg/L concentration of cypermethrin at both treatments. Dissolved oxygen decreased and free CO2 increased significantly (P<0.05) with increasing temperature, while the pH of the water was almost unchanged throughout the study period. The present study indicated the impact of increased temperature on pesticide toxicity in the aquatic ecosystem.Progressive Agriculture 29 (1): 64-70, 2018 

scholarly journals Modeling the effect of temperature variability on malaria control strategies

2020 ◽  
Vol 15 ◽  
pp. 65
Author(s):  
Salisu M. Garba ◽  
Usman A. Danbaba
Keyword(s):  
Control Strategies ◽  
Effect Of Temperature ◽  
Bed Nets ◽  
Asymptotically Stable ◽  
Temperature Changes ◽  
Offspring Number ◽  
Local Asymptotic Stability ◽  
Reproduction Numbers ◽  
The Impact ◽  
Disease Free

In this study, a non-autonomous (temperature dependent) and autonomous (temperature independent) models for the transmission dynamics of malaria in a population are designed and rigorously analysed. The models are used to assess the impact of temperature changes on various control strategies. The autonomous model is shown to exhibit the phenomenon of backward bifurcation, where an asymptotically-stable disease-free equilibrium (DFE) co-exists with an asymptotically-stable endemic equilibrium when the associated reproduction number is less than unity. This phenomenon is shown to arise due to the presence of imperfect vaccines and disease-induced mortality rate. Threshold quantities (such as the basic offspring number, vaccination and host type reproduction numbers) and their interpretations for the models are presented. Conditions for local asymptotic stability of the disease-free solutions are computed. Sensitivity analysis using temperature data obtained from Kwazulu Natal Province of South Africa [K. Okuneye and A.B. Gumel. Mathematical Biosciences 287 (2017) 72–92] is used to assess the parameters that have the most influence on malaria transmission. The effect of various control strategies (bed nets, adulticides and vaccination) were assessed via numerical simulations.

scholarly journals The effect of temperature on differentSalmonellaserotypes during warm seasons in a Mediterranean climate city, Adelaide, Australia

2015 ◽  
Vol 144 (6) ◽  
pp. 1231-1240 ◽  
Author(s):  
A. MILAZZO ◽  
L. C. GILES ◽  
Y. ZHANG ◽  
A. P. KOEHLER ◽  
J. E. HILLER ◽  
...  
Keyword(s):  
Phage Type ◽  
Warm Season ◽  
Substantial Effect ◽  
Effect Of Temperature ◽  
Temperature Sensitive ◽  
Ambient Temperatures ◽  
Policy Interventions ◽  
Long Term Trends ◽  
Higher Temperature ◽  
The Impact

SUMMARYChanging trends in foodborne disease are influenced by many factors, including temperature. Globally and in Australia, warmer ambient temperatures are projected to rise if climate change continues.Salmonellaspp. are a temperature-sensitive pathogen and rising temperature can have a substantial effect on disease burden affecting human health. We examined the relationship between temperature andSalmonellaspp. and serotype notifications in Adelaide, Australia. Time-series Poisson regression models were fit to estimate the effect of temperature during warmer months onSalmonellaspp. and serotype cases notified from 1990 to 2012. Long-term trends, seasonality, autocorrelation and lagged effects were included in the statistical models. DailySalmonellaspp. counts increased by 1·3% [incidence rate ratio (IRR) 1·013, 95% confidence interval (CI) 1·008–1·019] per 1 °C rise in temperature in the warm season with greater increases observed in specific serotype and phage-type cases ranging from 3·4% (IRR 1·034, 95% CI 1·008–1·061) to 4·4% (IRR 1·044, 95% CI 1·024–1·064). We observed increased cases ofS. Typhimurium PT9 andS. Typhimurium PT108 notifications above a threshold of 39 °C. This study has identified the impact of warm season temperature on differentSalmonellaspp. strains and confirms higher temperature has a greater effect on phage-type notifications. The findings will contribute targeted information for public health policy interventions, including food safety programmes during warmer weather.

Atomistic simulation for configuration evolution and energetic calculation of crack in body-centered-cubic iron

2006 ◽  
Vol 21 (10) ◽  
pp. 2542-2549 ◽  
Author(s):  
Li-Xia Cao ◽  
Chong-Yu Wang
Keyword(s):  
Low Temperatures ◽  
Crack Tip ◽  
Dislocation Nucleation ◽  
Effect Of Temperature ◽  
Body Centered Cubic ◽  
Partial Dislocations ◽  
Higher Temperature ◽  
Crack Blunting ◽  
Increasing Temperature ◽  
Extended Dislocation

The molecular dynamics method has been used to simulate mode I cracking in body-centered-cubic iron. Close attention has been paid to the process of the atomic configuration evolution of the cracks. The simulation shows that at low temperatures, partial dislocations are emitted before the initiation of crack propagation, subsequently forming the stacking faults or multilayer twins on {112} planes, and then brittle cleavage and extended dislocation nucleation are observed at the crack tip accompanied by twin extension. These results are in agreement with the experimental observation that twinning and fracture processes cooperate at low temperatures. Furthermore, an energetics analysis has been made on the deformation behavior observed at the crack tip. The effect of temperature on the fracture process is discussed. At the higher temperature, plastic deformation becomes easier, and crack blunting occurs. With increasing temperature, the fracture resistance increases, and the effect of the lattice trapping can be weakened by thermal activation.

scholarly journals The impact of temperature changes on summer time ozone and its' precursors in the Eastern Mediterranean

2011 ◽  
Vol 11 (2) ◽  
pp. 4355-4398
Author(s):  
U. Im ◽  
K. Markakis ◽  
A. Poupkou ◽  
D. Melas ◽  
A. Unal ◽  
...  
Keyword(s):  
Urban Areas ◽  
Eastern Mediterranean ◽  
Air Pollutant ◽  
Atmospheric Composition ◽  
Effect Of Temperature ◽  
Base Case ◽  
Temperature Changes ◽  
Urban Agglomerations ◽  
Atmospheric Processes ◽  
The Impact

Abstract. Changes in temperature due to variability in meteorology and climate change are expected to significantly impact atmospheric composition. The Mediterranean is a climate sensitive region and includes megacities like Istanbul and large urban agglomerations such as Athens. The effect of temperature changes on gaseous air pollutant levels and the atmospheric processes that are controlling them in the Eastern Mediterranean are here investigated. The WRF/CMAQ mesoscale modeling system is used, coupled with the MEGAN model for the processing of biogenic volatile organic compound emissions. A set of temperature perturbations (spanning from 1 to 5 K) is applied on a base case simulation corresponding to July 2004. The results indicate that the Eastern Mediterranean basin acts as a reservoir of pollutants and their precursor emissions from large urban agglomerations. During summer, chemistry is a major sink at these urban areas near the surface, and a minor contributor at downwind areas. On average, the atmospheric processes are more effective within the first 1000 m. The response rate of biogenic emissions to temperature changes is calculated to be 9±3% K−1. Ozone concentrations respond almost linearly to the changes in the ambient temperature with rates of 1±0.1 ppb O3 K−1 for all studied urban and receptor stations except for Istanbul, where a 0.4±0.1 ppb O3 K−1 change rate is calculated, which is almost half of the domain-averaged increase of 0.9±0.1 ppb O3 K−1. The computed changes in atmospheric processes are also linearly related with temperature changes.

The effect of some environmental conditions on seed development and hard-seededness in subterranean clover (Trifolium subterraneum L.)

1979 ◽  
Vol 30 (1) ◽  
pp. 65 ◽  
Author(s):  
GB Taylor ◽  
MJ Palmer
Keyword(s):  
Seed Development ◽  
Seed Size ◽  
Field Experiments ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Moisture Stress ◽  
Effect Of Temperature ◽  
Temperature Regimes ◽  
Increasing Temperature ◽  
Dry Out

Subterranean clover (cv. Daliak) was grown in boxes with provision for unrestricted lateral growth. At the commencement of flowering, plants were allocated to three day/night temperature regimes of 12/7°, 18/13° and 24/19°C in controlled-temperature glasshouses and well watered until maturity (unstressed). In two additional treatments at 18/13°, plants were either subjected to intermittent moisture stress throughout the flowering period (stressed) or well watered for the first 6 weeks of flowering and then allowed to dry out (droughted). Increasing temperature resulted in more rapid inflorescence production, seed development and earlier plant maturation. The overall mean seed size was lower at 24/19° than at the other two temperatures. The stressed and droughted treatments produced fewer and smaller seeds than the corresponding unstressed treatment. There was a small effect of temperature on the degree of hard-seededness as determined from the mean softening time of seed subjected to daily alternating temperatures of 60/15°. Softening time was not significantly affected by watering treatments. There were small differences in softening time due to the position of the burr on the lateral, with a slight trend for seeds from the first-formed burrs to soften more rapidly. Most of the variation in softening time between seeds was due to variation within burrs. The sequence of seed softening within burrs was related to seed size, the larger seeds generally softening first, but no single regression could be used to describe this relationship for different burr positions or treatments. The absence of major treatment effects on the degree of hard-seededness indicates that varying the length of the seed development period does not necessarily result in differences in hard-seededness, as has been suggested from field experiments.

Temperature Effects on Translocation Patterns of Several Herbicides within Quackgrass (Agropyron repens)

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 545-552 ◽  
Author(s):  
K. Neil Harker ◽  
Jack Dekker
Keyword(s):  
Methyl Ester ◽  
Ethyl Ester ◽  
Growth Temperature ◽  
Temperature Effects ◽  
Butyl Ester ◽  
Effect Of Temperature ◽  
Night Temperature ◽  
Rhizome Growth ◽  
Temperature Regimes ◽  
Increasing Temperature

A growth cabinet study was conducted to evaluate the effect of temperature on the distribution of several herbicides in quackgrass. Uniformly labeled14C-sucrose and the radiolabeled herbicides glyphosate, sethoxydim, cloproxydim, the butyl ester of fluazifop, the methyl ester of haloxyfop, and the ethyl ester of quizalofop were applied to quackgrass grown at three day / night temperature regimes (10/5, 20/15, and 30/25 C). Seven days after treatment the plants were harvested, lyophilized, and later sectioned, mapped, and oxidized in preparation for14C quantification. Quackgrass rhizome growth was more vigorous at 20/15 than 30/25 or 10/5 C. of the herbicides tested, haloxyfop was the most inhibitory to rhizome growth. Temperature increases from 10/5 to 20/15 or from 20/15 to 30/25 C resulted in more translocation to shoots. Increasing temperature had various effects on translocation to rhizomes depending on the chemical applied. At all three temperature regimes, more14C was recovered from distal than basal buds in plants treated with14C-sethoxydim. In contrast, at all three temperature regimes, similar amounts of14C were recovered from the distal and basal buds of plants treated with 14-C-sucrose.

scholarly journals The effect of temperature on the development and reproduction of Busseola fusca (Lepidoptera: Noctuidae)

2016 ◽  
Vol 107 (1) ◽  
pp. 39-48 ◽  
Author(s):  
J. Glatz ◽  
H. du Plessis ◽  
J. Van den Berg
Keyword(s):  
Larval Development ◽  
Busseola Fusca ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Single Male ◽  
Temperature Regimes ◽  
Threshold Temperatures ◽  
Thermal Constants ◽  
Lower Temperature ◽  
The Impact

AbstractThe effect of temperature on the reproduction and development of Busseola fusca was studied under laboratory conditions. Single male–female pairs were confined to oviposition chambers kept at 15, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. Data on reproduction parameters were captured daily. Oviposition occurred at all the mentioned temperatures but no fertility was recorded at 30°C. The total number of eggs laid per female moth was between 300 and 400 and the optimum temperature for oviposition and fertility was between 20 and 26°C. Larval development was studied at five different temperature regimes, i.e. 15, 18, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. The most favourable temperature as well as the upper threshold temperature for larval development was between 26 and 30°C. Total development period was 152.6–52.6 days, respectively, at 15°C, and 26–30°C. The thermal constants for B. fusca was 99.50, 536.48, 246.25 and 893.66°D and lower temperature thresholds were 10.36, 8.14, 8.99 and 8.84°C, for completion of the egg, larval, pupal and egg-to-adult stages, respectively. Results on the thermal constants and lower and upper threshold temperatures of B. fusca can be used to predict the impact of climate change on the distribution and population growth of this pest.

scholarly journals The impact of temperature changes on summer time ozone and its precursors in the Eastern Mediterranean

2011 ◽  
Vol 11 (8) ◽  
pp. 3847-3864 ◽  
Author(s):  
U. Im ◽  
K. Markakis ◽  
A. Poupkou ◽  
D. Melas ◽  
A. Unal ◽  
...  
Keyword(s):  
Urban Areas ◽  
Eastern Mediterranean ◽  
Air Pollutant ◽  
Atmospheric Composition ◽  
Effect Of Temperature ◽  
Base Case ◽  
Temperature Changes ◽  
Urban Agglomerations ◽  
Atmospheric Processes ◽  
The Impact

Abstract. Changes in temperature due to variability in meteorology and climate change are expected to significantly impact atmospheric composition. The Mediterranean is a climate sensitive region and includes megacities like Istanbul and large urban agglomerations such as Athens. The effect of temperature changes on gaseous air pollutant levels and the atmospheric processes that are controlling them in the Eastern Mediterranean are here investigated. The WRF/CMAQ mesoscale modeling system is used, coupled with the MEGAN model for the processing of biogenic volatile organic compound emissions. A set of temperature perturbations (spanning from 1 to 5 K) is applied on a base case simulation corresponding to July 2004. The results indicate that the Eastern Mediterranean basin acts as a reservoir of pollutants and their precursor emissions from large urban agglomerations. During summer, chemistry is a major sink at these urban areas near the surface, and a minor contributor at downwind areas. On average, the atmospheric processes are more effective within the first 1000 m above ground. Temperature increases lead to increases in biogenic emissions by 9±3% K−1. Ozone mixing ratios increase almost linearly with the increases in ambient temperatures by 1±0.1 ppb O3 K−1 for all studied urban and receptor stations except for Istanbul, where a 0.4±0.1 ppb O3 K−1 increase is calculated, which is about half of the domain-averaged increase of 0.9±0.1 ppb O3 K−1. The computed changes in atmospheric processes are also linearly related with temperature changes.

Experimental Study on the Effect of Temperature on Modal Frequencies of Bridges

2018 ◽  
Vol 18 (12) ◽  
pp. 1850155 ◽  
Author(s):  
Limin Sun ◽  
Yi Zhou ◽  
Zhihua Min
Keyword(s):  
Boundary Conditions ◽  
Freezing Point ◽  
Concrete Bridges ◽  
Effect Of Temperature ◽  
Steel Cable ◽  
Temperature Changes ◽  
Continuous Beam Bridge ◽  
Bridge Model ◽  
Increasing Temperature ◽  
Beam Bridge

This study investigates the relationship between the temperature and the modal frequencies of bridges through a series of model experiments using a concrete continuous beam bridge model and a steel cable-stayed bridge model in a controlled-temperature chamber. The experimental results show that, for a given boundary condition and in the absence of freezing, a change in temperature affects the structural frequencies of the bridge as it alters the elastic modulus of the bridge materials. The structural frequency tends to linearly decrease with increasing temperature and with the decrease in the frequency of steel bridges smaller than that of concrete bridges. For the particular case of wet concrete bridges, the temperature dependencies of modal frequencies vary dramatically near the freezing point, which is attributable to the freeze–thaw process of concrete pore water. The effect of air humidity on structural frequency is less significant than that of temperature when the boundary conditions remain unchanged. Furthermore, temperature changes may alter the boundary conditions of bridges, thereby affecting the structural frequencies.

Temperature effects on growth and maturity of butterfish (Pholis gunnellus) in Iceland

2002 ◽  
Vol 82 (5) ◽  
pp. 903-906 ◽  
Author(s):  
Ásgeir Gunnarsson ◽  
Karl Gunnarsson
Keyword(s):  
Growth Rate ◽  
Incubation Time ◽  
West Coast ◽  
Temperature Effects ◽  
Effect Of Temperature ◽  
The West ◽  
Sea Temperature ◽  
Temperature Regimes ◽  
Higher Temperature ◽  
Similar Growth

The effect of temperature on growth of butterfish, Pholis gunnellus on the west coast of Iceland was studied from September 1995 to March 1997. Butterfish were collected monthly at two sites with different temperature regimes. According to otolith readings butterfish can reach 12 years. The fish in the area with higher sea temperature were larger at all ages but had similar growth rates. Higher temperature seems to result in a shorter incubation time of butterfish eggs and/or higher growth rate of the larvae, leading to larger larvae size at settlement.

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