Worms decipher a bacterial code to drive multigenerational change in behavior

Review written by Olivia Duddy (MOL)

Segments of DNA, called genes, encode the expression of an organism’s traits. Genes are heritable, meaning that they are transmitted from the parent to their progeny. Additionally, scientists have uncovered mechanisms that enable changes in gene function, independent of changes in DNA sequence, that are also heritable. The study of these mechanisms, collectively known as epigenetics, has revealed ways in which the environment shapes our biology in the context of health and disease.

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Surprising events create event boundaries in memories

Review written by Paula Brooks (PNI)

Imagine that you are binge-watching Netflix. In spite of the algorithm’s calculations, you are getting bored by the show that was suggested and you are thinking about stopping before the end of the season. However, to your great surprise, a new character enters halfway through the season and you are hooked. The plot has gotten more interesting and the acting has suddenly improved. What just happened?

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Why some mosquitoes prefer biting us

Review written by Jessi Hennacy (MOL)

There are about 3500 mosquito species worldwide, but only a handful of them are responsible for the transmission of mosquito-borne illnesses such as malaria and dengue fever. Whereas most mosquito species are generalists that lack a preference for a particular animal, the specialist mosquito species that prefer biting humans over other animals are also the species that most widely spread human diseases. Understanding the environmental factors that are driving these mosquitoes to prefer humans could help uncover strategies for mitigating the spread of mosquito-borne illnesses. It is therefore vital for public health to ask why and how certain mosquitoes have evolved to target humans.

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Can people accurately predict emotions in others?

emotions study

Review written by Rohini Majumdar (PSY)

People tend to transition between emotional states in predictable patterns. We use what we know about how others are feeling in the moment to predict how they might feel in the future. Specifically, we make these predictions based on our knowledge of emotional state transition patterns from observing ourselves and others. Research has shown that benefits of social perception and prediction include positive real-world social outcomes such as stronger relationships with friends, higher satisfaction in romantic relationships, greater acceptance from peers, and more success within one’s community. 

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A C. elegans model reveals mechanisms behind reproductive aging

Written by Ashley Chang (MOL, 2021) and Rebekah Rashford (PNI, G3)

Physiological decline is a natural component of human aging. One of the biological processes perhaps most rapidly affected by this decline is that of reproduction in women. The quantity and quality of a woman’s eggs decreases as she ages, thereby reducing the likelihood of a successful pregnancy as she approaches her late 30s to early 40s. Pregnancy in humans at all is relatively impossible after menopause, which typically occurs in the late 40s and beyond. Because of these biological restrictions, doctors and researchers have developed treatments to help women who want to have children later in life, such as freezing their eggs or in vitro fertilization followed by freezing of the embryos. While these treatments have undoubtedly changed the landscape of modern conception and fertility, they do not directly combat the deleterious effects of reproductive aging. Instead of creating systems that circumvent the inevitable, what if we could challenge the issue head-on by preventing deterioration in the quality of the egg precursor, the oocyte, and extending the reproductive age-span? 

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The false duality of habitual versus goal-directed behavior

Written by Anika Maskara ‘23 & Thiago Tarraf Varella (PSY GS)

It is common in popular culture to imagine human decision making as a clash of two distinct choices. There is a “good option” and a “bad option,” an angel or a devil sitting on our shoulders. Like many dichotomies, though, that view of decision making is misleading. It is true that research suggests we have two different decision-making systems that sometimes disagree about which action to take, but neither is better or worse than the other; they simply use different algorithms to help us decide what to do.

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Parents are encouraged to read to their children when they're young, but is this really so important?

Written by Munisa Said (PSY, 2022) & Crystal Lee (PSY, G2)

Why is it so important for parents to read to their children? Previous research has found that when parents read to their infants (also called “shared reading”), there are significant improvements in early language development (Mol & Bus, 2011). However, not all children broadly benefit from shared reading. The advantages of shared reading vary quite widely among children. A recent paper led by researchers from Princeton and Rutgers Universities endeavored to explain this variability by considering genetic factors that may impact this development of language acquisition. In previous studies, individual differences in dopaminergic and serotonergic systems (the neural pathways that deliver dopamine and serotonin throughout the brain) have been implicated in different outcomes for learning, attention, and behavior.  Thus, Jiminez et al. examined the genetic characteristics of these systems of almost 2,000 children in order to see if this variable also explained the diverse effects of shared reading.

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Biophysical modeling of liquid-liquid interactions helps scientists understand cell division

Review written by Alexandra Libby (PNI)

Cell division is one of the most important and well-studied biological processes. Organisms generate new cells in order to grow and reproduce (Figure 1); the types of cell division responsible for each of these goals are called mitosis and meiosis, respectively. Like many biological processes, cell division involves a well-timed, complex coordination of proteins and cellular machinery. Disrupted division can lead to a multitude of problems including genetic mutations, cell death, and cancer (Zhivotovsky and Orrenius, 2010). 

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Life: Like oil and water? Part II

Part II of our series into the phenomenon of phase separation that is changing how biologists understand cellular biology

Review written by Xinyang (David) Bing (LSI)

“Repression condensates”

“For liquid-liquid phase separation, Princeton is the center of the universe, and my work benefited from collaborations and interactions with Cliff Brangwynne's lab.” 

This is how Dr. Nicholas Treen, from the lab of Mike Levine, described his close working relationship with the neighboring Brangwynne lab. In his latest publication, he and his collaborators set out to describe a novel type of condensate formation in the nucleus involved in gene silencing. 

The first cell divisions of a newly fertilized embryo are arguably the most instrumental events that occur throughout the life of an animal. During early embryonic development, an intricate web of processes must occur coordinately to lay the blueprint for the developing organism. Like a set of dominoes, every gene that is expressed during early developmental processes leads to consequences downstream during later developmental stages. Even slight errors may lead to a malfunctioning embryo and certain death of the animal. Therefore, all animals have their own set of developmental “blueprints” that necessitate massive numbers of genes be expressed in a tightly controlled manner, both in terms of timing and levels. 

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Pandemics Depress the Economy, Public Health Interventions Do Not: Evidence from the 1918 Flu

Review written by Yinuo Zhang (ECON)

The tradeoff between social distancing and its potential adverse economic effects has been at the center of debates during COVID-19 in the United States. On one hand, it is crucial to practice social distancing to prevent further spread of COVID-19. On the other hand, economic activities plummeted due to the closing of non-essential businesses mandated by many states. As a result, initial unemployment claims reached an unprecedented number of over 6.8 million on March 28th, the highest since 1967. The rapid development of COVID-19 has called urgent attention to the impact of existing public health interventions and its consequences on the real economy. In particular, do non-pharmaceutical interventions (NPI) like social distancing further hinder economic activity on top of the ongoing pandemic? Does the tradeoff between social distancing and subdued economic activities exist?

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