In nature, several organisms possess a magnetic compass to navigate or migrate them to desired locations. It is thought that these organisms may use biogenic magnetic matter or light-sensitive photoreceptors to sense ...In nature, several organisms possess a magnetic compass to navigate or migrate them to desired locations. It is thought that these organisms may use biogenic magnetic matter or light-sensitive photoreceptors to sense and orient themselves in magnetic fields. To unravel the underlying principles of magnetosensitivity and magnetoreception, previous experiments have been conducted on bacteria, vertebrates, crustaceans, and insects. In this study, the model organism, C. elegans, is used to test their response and sensitivity to static magnetic fields in the range of 5 milli Tesla to 120 milli Tesla. Single wild-type C. elegans are put in microfluidic channels and exposed to permanent magnets for five cycles of thirty-second time intervals. The worm movement is recorded and analyzed with custom software to calculate the average velocity and the percentage of turning and curling. Contrary to some published studies, our results did not show a significant difference compared to control experiments. This suggests that C. elegans may not sense static magnetic fields in the range of field strengths that we tested.展开更多
Nematodes are microscopic, soil-dwelling worms that navigate through soil particles in search of food or a suitable host. Most nematode species employ a myriad of physical and chemical cues that define their navigatio...Nematodes are microscopic, soil-dwelling worms that navigate through soil particles in search of food or a suitable host. Most nematode species employ a myriad of physical and chemical cues that define their navigation strategies. Here, we demonstrate a microfluidic method to observe and characterize the physical aspects of nematode navigation at real-time. The microfluidic devices comprise a series of interconnected T-maze or cylindrical structures of varying geometry. At each physical intersection, nematodes are given the choice to migrate left or right. We found that this decision-making of nematodes is influenced by the angle of intersection of T-maze structures. We further showed that nematodes can be passively directed to move in a linear direction by carefully adjusting the position and spacing of cylindrical obstacles in its path. The experiments were conducted on two nematodes (non-parasitic C. elegans and pigparasitic Oesophagostomum dentatum) and in the absence of any chemical or electrical stimulants.展开更多
Published literature has shown conflicting results regarding the effects of magnetic fields on the fermentation kinetics or cellular growth of various Saccharomyces cerevisiae strains. Here, two sets of experiments we...Published literature has shown conflicting results regarding the effects of magnetic fields on the fermentation kinetics or cellular growth of various Saccharomyces cerevisiae strains. Here, two sets of experiments were conducted to characterize the role of magnetic fields on cell growth and ethanol production during fermentation. The first experiment was completed for 25 h at a 2% dextrose loading rate under influence of homogeneous and non-homogeneous static magnetic fields on the order of 100 and 200 mT, respectively. The second experiment was completed for 30 h at a 6% dextrose loading rate under the influence of a non-homogeneous static magnetic field on the order of 200 mT. It was found that homogeneous magnetic fields have no significant effect on the yeast cell growth, while non-homogeneous static magnetic fields produced an increase (~ 8% over the control) in peak ethanol concentration with 2% dextrose loading.展开更多
文摘In nature, several organisms possess a magnetic compass to navigate or migrate them to desired locations. It is thought that these organisms may use biogenic magnetic matter or light-sensitive photoreceptors to sense and orient themselves in magnetic fields. To unravel the underlying principles of magnetosensitivity and magnetoreception, previous experiments have been conducted on bacteria, vertebrates, crustaceans, and insects. In this study, the model organism, C. elegans, is used to test their response and sensitivity to static magnetic fields in the range of 5 milli Tesla to 120 milli Tesla. Single wild-type C. elegans are put in microfluidic channels and exposed to permanent magnets for five cycles of thirty-second time intervals. The worm movement is recorded and analyzed with custom software to calculate the average velocity and the percentage of turning and curling. Contrary to some published studies, our results did not show a significant difference compared to control experiments. This suggests that C. elegans may not sense static magnetic fields in the range of field strengths that we tested.
文摘Nematodes are microscopic, soil-dwelling worms that navigate through soil particles in search of food or a suitable host. Most nematode species employ a myriad of physical and chemical cues that define their navigation strategies. Here, we demonstrate a microfluidic method to observe and characterize the physical aspects of nematode navigation at real-time. The microfluidic devices comprise a series of interconnected T-maze or cylindrical structures of varying geometry. At each physical intersection, nematodes are given the choice to migrate left or right. We found that this decision-making of nematodes is influenced by the angle of intersection of T-maze structures. We further showed that nematodes can be passively directed to move in a linear direction by carefully adjusting the position and spacing of cylindrical obstacles in its path. The experiments were conducted on two nematodes (non-parasitic C. elegans and pigparasitic Oesophagostomum dentatum) and in the absence of any chemical or electrical stimulants.
文摘Published literature has shown conflicting results regarding the effects of magnetic fields on the fermentation kinetics or cellular growth of various Saccharomyces cerevisiae strains. Here, two sets of experiments were conducted to characterize the role of magnetic fields on cell growth and ethanol production during fermentation. The first experiment was completed for 25 h at a 2% dextrose loading rate under influence of homogeneous and non-homogeneous static magnetic fields on the order of 100 and 200 mT, respectively. The second experiment was completed for 30 h at a 6% dextrose loading rate under the influence of a non-homogeneous static magnetic field on the order of 200 mT. It was found that homogeneous magnetic fields have no significant effect on the yeast cell growth, while non-homogeneous static magnetic fields produced an increase (~ 8% over the control) in peak ethanol concentration with 2% dextrose loading.
