scholarly journals Drosophilaembryogenesis scales uniformly across temperature and developmentally diverse species

2013 ◽  
Author(s):  
Steven Gregory Kuntz ◽  
Michael B Eisen
Keyword(s):  
Thermal Environment ◽  
Time Lapse ◽  
Egg Laying ◽  
Tropical Species ◽  
Relative Timing ◽  
Animal Development ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Time Lapse Imaging ◽  
The Impact

Temperature affects both the timing and outcome of animal development, but the detailed effects of temperature on the progress of early development have been poorly characterized. To determine the impact of temperature on the order and timing of events duringDrosophila melanogasterembryogenesis, we used time-lapse imaging to track the progress of embryos from shortly after egg laying through hatching at seven precisely maintained temperatures between 17.5°C and 32.5°C. We employed a combination of automated and manual annotation to determine when 36 milestones occurred in each embryo.D. melanogasterembryogenesis takes 33 hours at 17.5°C, and accelerates with increasing temperature to a low of 16 hours at 27.5°C, above which embryogenesis slows slightly. Remarkably, while the total time of embryogenesis varies over two fold, the relative timing of events from cellularization through hatching is constant across temperatures. To further explore the relationship between temperature and embryogenesis, we expanded our analysis to cover ten additionalDrosophilaspecies of varying climatic origins. Six of these species, likeD. melanogaster, are of tropical origin, and embryogenesis time at different temperatures was similar for them all.D. mojavensis, a sub-tropical fly, develops slower than the tropical species at lower temperatures, whileD. virilis, a temperate fly, exhibits slower development at all temperatures. The alpine sister speciesD. persimilisandD. pseudoobscuradevelop as rapidly as tropical flies at cooler temperatures, but exhibit diminished acceleration above 22.5°C and have drastically slowed development by 30°C. Despite ranging from 13 hours forD. erectaat 30°C to 46 hours forD. virilisat 17.5°C, the relative timing of events from cellularization through hatching is constant across all of the species and temperatures examined here, suggesting the existence of a previously unrecognized timer controlling the progress of embryogenesis that has been tuned by natural selection in response to the thermal environment in which each species lives.

Temperature Dependence of Hole Impact Ionization Coefficient in 4H-SiC Photodiodes

2009 ◽  
Vol 615-617 ◽  
pp. 311-314 ◽  
Author(s):  
W.S. Loh ◽  
J.P.R. David ◽  
B.K. Ng ◽  
Stanislav I. Soloviev ◽  
Peter M. Sandvik ◽  
...  
Keyword(s):  
Phonon Scattering ◽  
Impact Ionization ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Different Temperatures ◽  
Ionization Coefficients ◽  
Increasing Temperature ◽  
The Impact ◽  
Good Agreement ◽  
Ionization Rates

Hole initiated multiplication characteristics of 4H-SiC Separate Absorption and Multiplication Avalanche Photodiodes (SAM-APDs) with a n- multiplication layer of 2.7 µm were obtained using 325nm excitation at temperatures ranging from 300 to 450K. The breakdown voltages increased by 200mV/K over the investigated temperature range, which indicates a positive temperature coefficient. Local ionization coefficients, including the extracted temperature dependencies, were derived in the form of the Chynoweth expression and were used to predict the hole multiplication characteristics at different temperatures. Good agreement was obtained between the measured and the modeled multiplication using these ionization coefficients. The impact ionization coefficients decreased with increasing temperature, corresponding to an increase in breakdown voltage. This result agrees well with the multiplication characteristics and can be attributed to phonon scattering enhanced carrier cooling which has suppressed the ionization process at high temperatures. Hence, a much higher electric field is required to achieve the same ionization rates.

scholarly journals Spectroscopic and Molecular Modeling Investigation on the Interaction between Folic Acid and Bovine Lactoferrin from Encapsulation Perspectives

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 744
Author(s):  
Iuliana Aprodu ◽  
Loredana Dumitrașcu ◽  
Gabriela Râpeanu ◽  
Gabriela-Elena Bahrim ◽  
Nicoleta Stănciuc
Keyword(s):  
Folic Acid ◽  
Molecular Modeling ◽  
Thermal Treatment ◽  
Tertiary Structure ◽  
Emission Spectra ◽  
Bovine Lactoferrin ◽  
Different Temperatures ◽  
Static Mechanism ◽  
Increasing Temperature ◽  
The Impact

The impact of thermal treatment on the ability of lactoferrin (FL) to bind folic acid (FA) was investigated by employing fluorescence spectroscopy, molecular dynamics and docking tests. The structural and conformational particularities of LF upon heating at 80 °C and 100 °C were first estimated based on the intrinsic fluorescence changes in respect to the native protein. The emission spectra indicated gradual unfolding events accompanied by Trp exposure with increasing temperature. In agreement with the experimental results, molecular modeling investigations showed that the secondary and tertiary structure of LF are slightly affected by the thermal treatment. Some minor unfolding events related particularly to the α-helical regions of LF were observed when the temperature increased to 100 °C. The LF fluorescence quenching upon FA addition indicated that a static mechanism stands behind LF-FA complex formation. Regardless of the simulated temperature, the hydrogen bonds played an important role in regulating the interaction between the protein and ligand. FA binding to LF equilibrated at different temperatures occurred spontaneously, and all complexes displayed good thermodynamic stability. The obtained results support the suitability of LF as biocompatible material, for obtaining micro- and nanoparticles for delivery of dietary supplements or for enhancing the functionality of target delivery systems.

scholarly journals The Effects of Temperature and of Egg-Laying on the Longevity of Drosophila subobscura

2002 ◽  
Vol 2002 (37) ◽  
Author(s):  
J. Maynard Smith
Keyword(s):  
Animal Species ◽  
Initial Period ◽  
Egg Laying ◽  
Drosophila Subobscura ◽  
Force Of Mortality ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Favourable Environment ◽  
Rate Of Ageing ◽  
Increasing Temperature

If an outbred population of adult Drosophila is kept from the time of emergence in a uniform and favourable environment there is a fairly protracted initial period during which very few individuals die, followed by a period during which the force of mortality rises rapidly until all individuals are dead. Similar life tables can be obtained for most animal species, provided that the environment is favourable and the population is neither genetically very diverse nor excessively inbred. Such results show that progressive changes take place in individuals, starting at the time of emergence, and that these changes ultimately result in death or render individuals increasingly susceptible to various extrinsic causes of death. As would be expected, in poikilotherms such changes proceed more rapidly at higher temperatures, as is shown by the decrease in the expectation of life with increasing temperature. It was the purpose of the present investigation to discover how far the processes responsible for death in D. subobscura are the same at different temperatures, differing only in the rate at which they proceed, and how far different processes are concerned at different temperatures. The results obtained strongly suggest that different processes are responsible for ageing at different temperatures; they also indicate a connexion between the rate of egg-laying and the rate of ageing, and this possibility has been confirmed by a study of ageing in virgin females and in females lacking ovaries. Reproduced by permission. J. Maynard Smith, The Effects of Temperature and of Egg-Laying on the Longevity of Drosophila subobscura. J. Exp. Biol. 35 , 832-842 (1958).

scholarly journals Direct Visualization of Amlodipine Intervention into Living Cells by Means of Fluorescence Microscopy

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2997
Author(s):  
Christine Quentin ◽  
Rūta Gerasimaitė ◽  
Alexandra Freidzon ◽  
Levon S. Atabekyan ◽  
Gražvydas Lukinavičius ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Aqueous Solutions ◽  
Time Lapse ◽  
Drug Uptake ◽  
Live Cells ◽  
Direct Visualization ◽  
Cellular Environment ◽  
Time Lapse Imaging ◽  
The Impact

Amlodipine, a unique long-lasting calcium channel antagonist and antihypertensive drug, has weak fluorescence in aqueous solutions. In the current paper, we show that direct visualization of amlodipine in live cells is possible due to the enhanced emission in cellular environment. We examined the impact of pH, polarity and viscosity of the environment as well as protein binding on the spectral properties of amlodipine in vitro, and used quantum chemical calculations for assessing the mechanism of fluorescence quenching in aqueous solutions. The confocal fluorescence microscopy shows that the drug readily penetrates the plasma membrane and accumulates in the intracellular vesicles. Visible emission and photostability of amlodipine allow confocal time-lapse imaging and the drug uptake monitoring.

Study of Head Concussions on Female Soccer Players

2018 ◽  
Author(s):  
Peyman Honarmandi ◽  
Alessandra Palmisano ◽  
Iryna Stashuk ◽  
Shawn Ladda
Keyword(s):  
Time Lapse ◽  
Soccer Players ◽  
Head Acceleration ◽  
Projectile Motion ◽  
Head Injury Criterion ◽  
Extent Of Damage ◽  
Time Lapse Imaging ◽  
The Impact ◽  
The Brain ◽  
Computational Programming

The goal of this research is to evaluate the extent of damage to the brain in regard to concussions when female soccer players head the ball to pass, defend, and score goals. It is reported that female soccer players have higher concussion rates than male players, which is why they will be the focus of this study. The anatomy of the female body seems to be structured in a way that increases the risk of concussions, but that has not been verified yet. While many clinical studies document post-concussion results, our research evaluates the impact of the soccer ball during active play both computationally and experimentally. The force from the ball hitting the head and the resulting acceleration of the brain are analyzed. First, the head accelerations and corresponding HIC (Head Injury Criterion) values are obtained using computational programming. Then, a newly developed experimental framework is used to track the head acceleration using an accelerometer. The velocity and angle at which the ball makes contact with the head are measured using a projectile motion and time-lapse imaging technique. The results of heading the ball in different kick scenarios are compared with the threshold HIC values for concussions.

scholarly journals The impact of male age on embryo quality: a retrospective study using time-lapse imaging

2016 ◽  
Vol 20 (4) ◽  
pp. 212-216
Author(s):  
Guilherme R. F. Rosário ◽  
Diana S. Vidal ◽  
Adriana V. Silva ◽  
Antônio C. C. Franco
Keyword(s):  
Retrospective Study ◽  
Embryo Quality ◽  
Time Lapse ◽  
Male Age ◽  
Time Lapse Imaging ◽  
The Impact

Investigation of Impact Behavior of TIG Welded Inconel 718 at Aircraft Engine Operating Temperatures

2017 ◽  
Vol 890 ◽  
pp. 339-343
Author(s):  
Yagiz Uzunonat
Keyword(s):  
Inconel 718 ◽  
Impact Resistance ◽  
Aircraft Engine ◽  
Impact Behavior ◽  
Spectroscopy Analysis ◽  
Carbide Phases ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
The Impact ◽  
Pendulum Impact

In this work, Charpy notch pendulum impact test was performed on non-welded and TIG (Tungsten Inert Gas) welded Inconel 718 specimens at three different temperatures as 20°C, 500°C and 700°C. After the completion of tests, SEM (Scanning Electron Microscopy) inspection and EDX (Energy-Dispersive X-Ray Spectroscopy) analysis were performed for the microstructural examination of the specimens. Hardness measurements on the rupture zone of selected welded and non-welded specimens were also performed to make a better approach to interpretation of the impact behavior of material. Inspections indicated that hardness values in the heat affected zone of welded specimens dramatically decreased and they displayed higher ductility during fracture than non-welded samples due to partial softening of structure. The reason of further decrease in impact resistance of welded specimens was explained as the precipitation and coarsening of γ′′ and carbide phases in the interdendritic regions with increasing temperature.

Cleavage of Human Embryos: Options and Diversity

Acta Naturae ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 88-96
Author(s):  
Yu. K. Doronin ◽  
I. V. Senechkin ◽  
L. V. Hilkevich ◽  
M. A. Kurcer
Keyword(s):  
Time Lapse ◽  
Reproductive Technologies ◽  
Human Embryos ◽  
Imaging Data ◽  
Noninvasive Methods ◽  
Topographic Features ◽  
Time Parameters ◽  
Embryo Cleavage ◽  
Time Lapse Imaging ◽  
Developmental Dynamics

In order to estimate the diversity of embryo cleavage relatives to embryo progress (blastocyst formation), time-lapse imaging data of preimplantation human embryo development were used. This retrospective study is focused on the topographic features and time parameters of the cleavages, with particular emphasis on the lengths of cleavage cycles and the genealogy of blastomeres in 2- to 8-cell human embryos. We have found that all 4-cell human embryos have four developmental variants that are based on the sequence of appearance and orientation of cleavage planes during embryo cleavage from 2 to 4 blastomeres. Each variant of cleavage shows a strong correlation with further developmental dynamics of the embryos (different cleavage cycle characteristics as well as lengths of blastomere cycles). An analysis of the sequence of human blastomere divisions allowed us to postulate that the effects of zygotic determinants are eliminated as a result of cleavage, and that, thereafter, blastomeres acquire the ability of own syntheses, regulation, polarization, formation of functional contacts, and, finally, of specific differentiation. This data on the early development of human embryos obtained using noninvasive methods complements and extend our understanding of the embryogenesis of eutherian mammals and may be applied in the practice of reproductive technologies.

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