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Starts and Stops of Rhythmic and Discrete Movements: Modulation in the Excitability of the Corticomotor Tract During Transition to a Different Type of Movement

Lim et al. | Aug 27, 2018

Starts and Stops of Rhythmic and Discrete Movements: Modulation in the Excitability of the Corticomotor Tract During Transition to a Different Type of Movement

Control of voluntary and involuntary movements is one of the most important aspects of human neurological function, but the mechanisms of motor control are not completely understood. In this study, the authors use transcranial magnetic stimulation (TMS) to stimulate a portion of the motor cortex while subjects performed either discrete (e.g. throwing) or rhythmic (e.g. walking) movements. By recording electrical activity in the muscles during this process, the authors showed that motor evoked potentials (MEPs) measured in the muscles during TMS stimulation are larger in amplitude for discrete movements than for rhythmic movements. Interestingly, they also found that MEPs during transitions between rhythmic and discrete movements were nearly identical and larger in amplitude than those recorded during either rhythmic or discrete movements. This research provides important insights into the mechanisms of neurological control of movement and will serve as the foundation for future studies to learn more about temporal variability in neural activity during different movement types.

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Cathodal Galvanotaxis: The Effect of Voltage on the distribution of Tetrahymena pyriformis

Zheng et al. | Jun 10, 2019

Cathodal Galvanotaxis: The Effect of Voltage on the distribution of <em>Tetrahymena pyriformis</em>

The surface of the unicellular eukaryote, Tetrahymena pyriformis, is covered with thousands of hair-like cilia. These cilia are very similar to cilia of the human olfactory and respiratory tracts making them model organisms for studying cilia function and pathology. The authors of this study investigated the effect of voltage on T. pyriformis galvanotaxis, the movement towards an electrical stimulus. They observed galvanotaxis towards the cathode at voltages over 4V which plateau, indicating opening of voltage gated-ion channels to trigger movement.

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How Ethanol Concentration Affects Catalase Catalysis of Hydrogen Peroxide

Liu et al. | Nov 15, 2021

How Ethanol Concentration Affects Catalase Catalysis of Hydrogen Peroxide

Catalase is a critical enzyme in the human body because it is capable of converting potentially dangerous hydrogen peroxide into water and oxygen. This work asks whether ethanol affects catalase activity, as alcohol consumption has been often linked to hepatitis occurring in the liver, where catalase level is especially high, and ethanol is known to be capable of denaturing proteins. Testing different concentrations of ethanol found that higher concentrations reduced the activity of catalase. This work has important implications on the negative effects of ethanol on metabolism, in which catalase plays an important role, and protein function more broadly.

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The Non-Thermal Effect of UV-B Irradiation on Onion Growth

Nashnoush et al. | Jun 09, 2020

The Non-Thermal Effect of UV-B Irradiation on Onion Growth

UV-B radiation due to the depletion of ozone threatens plant life, potentially damaging ecosystems and dismantling food webs. Here, the impact of UV-B radiation on the physiology and morphology of Allum cepa, the common onion, was assessed. Mitosis vitality decreased, suggesting UV-B damage can influence the plant’s physiology.

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Effect of Fertilizer on Water Quality of Creeks over Time

Chen et al. | May 02, 2021

Effect of Fertilizer on Water Quality of Creeks over Time

Fertilizers are commonly used to improve agricultural yield. Unfortunately, chemical fertilizers can seep into drinking water, potentially harming humans and other forms of life. Here, the authors investigate the effect of fertilizer on the water quality of Saratoga Creek over time. They find that fertilizers can alter the acidity of the creek's water, which can be harmful to aquatic species, as well as increase the levels of nitrates temporarily.

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