SPENCER HART WINTER
The nascent field of molecular programming offers an opportunity for something new; biochemical circuits are engineered from scratch that perform boolean logic computations and demonstrate neural network functionality without electronics or relying on the traditional mechanisms of a cell.
They are a totally unique thing; a biochemical machine.
I want to make the biochemical machine concept literal creating the next generation of DNA-based soft robots that demonstrate prototypical eukaryotic behaviors through a completely different mode than that seen in life.
Fig. 2.1
Catalytic strand-displacement circuits, such as those using the seesaw motif, are capable of robust information processing via signal amplification. However, the signal restoration process means that spurious signals from leak, unintended chemical reactions, can be amplified and lead to incorrect outputs.
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While a Caltech WAVE Fellow in the Qian Lab I designed a gate complex that exploits the conformation change of the gate after output displacement, preventing the fuel strand from unintended interaction. Five variations of the design were tested both for leak and for functionality via a fluorescent output.
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This work is being continued as I complete a full kinetic and thermodynamic analysis of the gate designs for my Honors Capstone Project, and ties directly into my future goals as leak reduction is critical for soft robotic function at high DNA concentrations.
Fig. 2.2
In contrast with mammals, many fish display more abundant adult neurogenesis with up to 16 distinct and well-defined neurogenic niches. The aim of this project was to develop a brain map of the neurogenic zones in a new nonstandard and ethologically relevant fish model, the speckled sanddab (Citharichthys stigmaeus), a species native to Monterey Bay.
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Working with my CSUMB mentor Dr. De Miguel, the knowledge gained from my study could be used to determine whether neuroplasticity processes in the speckled sanddab contribute to physiological and behavioral adaptations in a constantly changing environment, with potential implications for survival.
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I received the Goldwater Scholarship in relation to this work.
Fig. 2.3
Decision making affects the daily lives of living beings and is a defining feature of cognitive flexibility. However, the underlying neural mechanisms of decision making are still not fully understood. This study hypothesizes that the ADS plays a role in determining how long evidence that is related to perceptual decision making is retained before being discarded, while the FOF plays a role in the decision selection itself based on the information routed via the ADS.
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This work was my first summer research experience and my first STEM experience. I worked with the Hanks Lab at the University of California: Davis Center for Neuroscience mapping the timescale of evidence accumulation. Their neural responses are recorded using Neuropixels probes, which allow simultaneous recording of action potentials from 384 of a total 960 selectable electrodes.
Fig. 2.4
Despite cultural myths and social taboos, young children are capable of understanding death and death concepts. This study aimed to differentiate children’s death concept between multiple forms of death, namely the difference between the deaths of a human, an animal, and an electronic device.
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As my first ever significant research experience, I designed a study with Dr. Weisskirch at CSUMB, where preschool-aged (3 to 5 years old) children were presented with photographs of people, animals, and toys and then asked questions about their deaths as they relate to the central aspects of death concept; irreversibility, non-functionality, and universality.
