ABSTRACT
Carbon dioxide (CO2 ) exposure is a common method of anesthesia in studies of Drosophila melanogaster. A number of negative side effects of CO2 anesthesia have been reported. It is not clear whether the length of CO2 anesthesia time affects Drosophila survival in aging research. Here, we examined the potential effect of the CO2 anesthesia time length of 10-150 min. We found that long CO2 exposure could lead to Drosophila death, more significant in males. The longer the anesthesia time is, the longer it takes for flies to wake up. Long-time CO2 anesthesia can reduce the lifespan. Our stress tests showed that long-time CO2 anesthesia can increase the average survival time in both males and females under starvation conditions, but can only increase female lifespan under H2 O2 oxidative stress. Long-time CO2 anesthesia also significantly affects physiological traits, with spontaneous activity increased in females but decreased in males, and reduced female fecundity. Our study suggests that limiting the CO2 anesthesia time and giving enough recovery time before performing physiological tests are important in Drosophila aging research.
Subject(s)
Carbon Dioxide/pharmacology , Drosophila melanogaster/drug effects , Aging , Anesthesia , Animals , Carbon Dioxide/toxicity , Drosophila melanogaster/physiology , Female , Fertility/drug effects , Food Deprivation , Hydrogen Peroxide/toxicity , Longevity/drug effects , Male , Oxidative Stress/drug effects , Sex Factors , Time FactorsABSTRACT
This Letter investigates the relative intensity noise (RIN) characteristics of a continuous-wave 3.4 µm interband cascade laser operated at room temperature. The RIN decreases with an increasing pump current and reaches down to -130 dB/Hz at a frequency of 450 MHz. In addition, it is proved that the current noise of the laser pump source dominates the RIN for frequencies below 100 MHz. The measured RIN is quantitatively in agreement with the theoretical analysis, from which the gain coefficient and the transparent carrier number of the laser are extracted.
ABSTRACT
We investigated the toxic effect of visible light on Drosophila life span in both sexes. The toxic effect of ultraviolet light on organisms is well known. However, the effects of illumination with visible light remain unclear. Here, we found that visible light could be toxic to Drosophila survival, depending on the protein content in diet. In addition, further analysis revealed significant interaction between light and sex and showed that strong light shortened life span by causing opposite direction changes in mortality rate parameters in females versus males. Our findings suggest that photoaging may be a general phenomenon and support the theory of sexual antagonistic pleiotropy in aging intervention. The results caution that exposure to visible light could be hazardous to life span and suggest that identification of the underlying mechanism would allow better understanding of aging intervention.
Subject(s)
Aging/radiation effects , Dietary Proteins/pharmacology , Energy Intake/physiology , Ultraviolet Rays/adverse effects , Aging/metabolism , Animals , Drosophila melanogaster , Energy Intake/radiation effects , Female , Male , Models, AnimalABSTRACT
The development and evaluation of a 6-hours laboratory class, based on capillary electrophoresis (CE) and the detection of microbial contaminants, is described. It can be easily scaled up or down, to suit class sizes up to 188 and completed in a shorter time scale. CE uses narrow-bore fused-silica capillaries to separate a complex array of large and small molecules. A laboratory exercise has been devised to illustrate how CE-based genetic analysis system processes DNA fragment analysis to detect three microbial contaminants. The protocol is relatively inexpensive and uses standard molecular biology reagents and equipment. © 2018 by The International Union of Biochemistry and Molecular Biology, 46(3):279-284, 2018.
