Mouse brain labeled using the brainbow technique. Brainbow is a technique used to distinguish individual neurons using different-colored derivatives of GFP (green fluorescent protein). By Dr. Tamily Weissman-Unni.
Breathe deep… and thank phytoplankton.
Why? Like plants on land, these microscopic creatures capture energy from the sun and carbon from the atmosphere to produce oxygen.
Phytoplankton are microscopic organisms that live in watery environments, both salty and fresh. Though tiny, these creatures are the foundation of the aquatic food chain. They not only sustain healthy aquatic ecosystems, they also provide important clues on climate change.
Let’s explore what these creatures are and why they are important for NASA research.
Phytoplankton are an extremely diversified group of organisms, varying from photosynthesizing bacteria, e.g. cyanobacteria, to diatoms, to chalk-coated coccolithophores. Studying this incredibly diverse group is key to understanding the health - and future - of our ocean and life on earth.
Their growth depends on the availability of carbon dioxide, sunlight and nutrients. Like land plants, these creatures require nutrients such as nitrate, phosphate, silicate, and calcium at various levels. When conditions are right, populations can grow explosively, a phenomenon known as a bloom.
Phytoplankton blooms in the South Pacific Ocean with sediment re-suspended from the ocean floor by waves and tides along much of the New Zealand coastline.
Phytoplankton are the foundation of the aquatic food web, feeding everything from microscopic, animal-like zooplankton to multi-ton whales. Certain species of phytoplankton produce powerful biotoxins that can kill marine life and people who eat contaminated seafood.
Phytoplankton play an important part in the flow of carbon dioxide from the atmosphere into the ocean. Carbon dioxide is consumed during photosynthesis, with carbon being incorporated in the phytoplankton, and as phytoplankton sink a portion of that carbon makes its way into the deep ocean (far away from the atmosphere).
Changes in the growth of phytoplankton may affect atmospheric carbon dioxide concentrations, which impact climate and global surface temperatures. NASA field campaigns like EXPORTS are helping to understand the ocean's impact in terms of storing carbon dioxide.
NASA studies phytoplankton in different ways with satellites, instruments, and ships. Upcoming missions like Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) - set to launch Jan. 2024 - will reveal interactions between the ocean and atmosphere. This includes how they exchange carbon dioxide and how atmospheric aerosols might fuel phytoplankton growth in the ocean.
Information collected by PACE, especially about changes in plankton populations, will be available to researchers all over the world. See how this data will be used.
The Ocean Color Instrument (OCI) is integrated onto the PACE spacecraft in the cleanroom at Goddard Space Flight Center. Credit: NASA
The incredibly stunning Port Jackson Shark, which lives on coastal reefs in Australia
Though it can be solitary it prefers to stay in small groups and explore the sea floor with its friends
What I love most about this shark is how surreal it looks due to the patterns of its skin
It is friendly and curious of people
An oviparous shark, it lays spiral eggs to keep the current from dragging babies into the open ocean
Probably the coolest shark jaw I’ve ever seen, most of its teeth are round and flat in order to crush clams and mollusks
How long is the present? The answer, Cornell researchers suggest in a new study, depends on your heart.
They found that our momentary perception of time is not continuous but may stretch or shrink with each heartbeat.
The research builds evidence that the heart is one of the brain’s important timekeepers and plays a fundamental role in our sense of time passing – an idea contemplated since ancient times, said Adam K. Anderson, professor in the Department of Psychology and in the College of Human Ecology (CHE).
“Time is a dimension of the universe and a core basis for our experience of self,” Anderson said. “Our research shows that the moment-to-moment experience of time is synchronized with, and changes with, the length of a heartbeat.”
Saeedeh Sadeghi, M.S. ’19, a doctoral student in the field of psychology, is the lead author of “Wrinkles in Subsecond Time Perception are Synchronized to the Heart,” published in the journal Psychophysiology. Anderson is a co-author with Eve De Rosa, the Mibs Martin Follett Professor in Human Ecology (CHE) and dean of faculty at Cornell, and Marc Wittmann, senior researcher at the Institute for Frontier Areas of Psychology and Mental Health in Germany.
Time perception typically has been tested over longer intervals, when research has shown that thoughts and emotions may distort our sense time, perhaps making it fly or crawl. Sadeghi and Anderson recently reported, for example, that crowding made a simulated train ride seem to pass more slowly.
Such findings, Anderson said, tend to reflect how we think about or estimate time, rather than our direct experience of it in the present moment.
To investigate that more direct experience, the researchers asked if our perception of time is related to physiological rhythms, focusing on natural variability in heart rates. The cardiac pacemaker “ticks” steadily on average, but each interval between beats is a tiny bit longer or shorter than the preceding one, like a second hand clicking at different intervals.
The team harnessed that variability in a novel experiment. Forty-five study participants – ages 18 to 21, with no history of heart trouble – were monitored with electrocardiography, or ECG, measuring heart electrical activity at millisecond resolution. The ECG was linked to a computer, which enabled brief tones lasting 80-180 milliseconds to be triggered by heartbeats. Study participants reported whether tones were longer or shorter relative to others.
The results revealed what the researchers called “temporal wrinkles.” When the heartbeat preceding a tone was shorter, the tone was perceived as longer. When the preceding heartbeat was longer, the sound’s duration seemed shorter.
“These observations systematically demonstrate that the cardiac dynamics, even within a few heartbeats, is related to the temporal decision-making process,” the authors wrote.
The study also showed the brain influencing the heart. After hearing tones, study participants focused attention on the sounds. That “orienting response” changed their heart rate, affecting their experience of time.
“The heartbeat is a rhythm that our brain is using to give us our sense of time passing,” Anderson said. “And that is not linear – it is constantly contracting and expanding.”
The scholars said the connection between time perception and the heart suggests our momentary perception of time is rooted in bioenergetics, helping the brain manage effort and resources based on changing body states including heart rate.
The research shows, Anderson said, that in subsecond intervals too brief for conscious thoughts or feelings, the heart regulates our experience of the present.
“Even at these moment-to-moment intervals, our sense of time is fluctuating,” he said. “A pure influence of the heart, from beat to beat, helps create a sense of time.”
Books and bookmarks
...with a belief that my subjectivity is the only slice of eternity I am entitled to.
ok well im going to build a good future for myself whether i like it or not