The human body is an intricate machine, constantly replacing billions of cells every day while maintaining perfect tissue organization. Researchers at ChristianaCare’s Helen F. Graham Cancer Center & Research Institute and the University of Delaware have cracked the “tissue code” – a set of five basic rules that explain how tissues like those in the colon stay organized even as their cells are constantly dying and being replaced.

After 15 years of collaboration between mathematicians and cancer biologists, the team identified these five core biological rules that govern cell behavior and tissue structure:

1. Cell migration: Cells move towards areas with specific signals.
2. Cell division: Cells divide in a controlled manner to maintain tissue density.
3. Apoptosis regulation: Cells self-destruct in a programmed way to prevent overgrowth.
4. Adhesion and detachment: Cells adhere to their neighbors and detach at the right time to maintain tissue integrity.
5. Signaling pathways: Cells communicate with each other through specific signaling pathways.

These rules work together like choreography, controlling where cells go, when they divide, and how long they stick around – keeping tissues looking and working as they should. The researchers believe these rules may apply not just to the colon but to many different tissues throughout the body, including skin, liver, brain, and beyond.

This discovery has significant implications for understanding tissue healing after injury, birth defects, and diseases like cancer that develop when this code gets disrupted. By identifying simple, universal rules that govern cell behavior and tissue structure, the findings could help guide future efforts to not only describe cells but predict how they behave in health and disease.

The team’s work also reflects a broader shift in how scientists approach complex problems – collaboration between biology and math. This kind of research aligns with national priorities, such as the National Science Foundation’s “Rules of Life” initiative, which challenges researchers to uncover fundamental principles that govern living systems.

Next steps for the team include testing the model’s predictions experimentally, refining it with additional data, and exploring its relevance to cancer biology – especially how disruptions to the tissue code may lead to tumor growth or metastasis. This is just the beginning of a promising new area of research that could lead to better understanding and treatment of diseases, as well as improved human health and longevity.

As you venture deeper into this unique landscape, notice the diverse reactions from locals as they interact with their feral neighbors. Some are filled with wonder, while others express concern for safety or environmental impact. This image captures the essence of the complex relationships between humans and wildlife in a semi-urban setting, where natural beauty and urbanization coexist in an intricate dance.

The City University of Hong Kong-led study reveals that public attitudes toward the buffalo fall into four key categories: appreciation and conditional acceptance; concern about community impacts; seeing them as valuable for conservation and education; and individual perceptions formed through everyday encounters. Neutral responses were most frequent, followed by positive and then negative responses.

Regarding the questions on Buffalo Tolerance and Appreciation, 61% of the responses were neutral, 25% highly positive, and 14% highly negative, with effects of age, gender, ethnicity, and birthplace. Looking at the questions on Buffalo Social Benefits and Advocacy, 66% of responses were neutral, 19% highly positive, and 15% highly negative, with significant effects of age and ethnicity.

A similar pattern was found for questions on Preservation and Education, where 46% of the responses were neutral, 41% highly positive, and 13% highly negative, with effects of gender, ethnicity, and birthplace. In the final section on Impacts on Daily Life, 49% of the responses were neutral, 27% highly positive, and 23% highly negative, with significant effects of age and ethnicity.

The study also found that familiarity with wildlife in rural areas often leads to more positive perceptions among participants. This suggests that education and exposure can play a crucial role in shaping attitudes toward feral animals in semi-urban settings.

Ultimately, the research highlights the importance of considering diverse perspectives when managing human-wildlife interactions in shared landscapes. By understanding the complexities of these relationships, we can work towards creating harmonious coexistence between humans and wildlife, even in the most unexpected places.

“Fish make hanging motionless in the water column look effortless, and scientists had long assumed that this meant it was a type of rest,” begins the article. However, a new study reveals that fish use nearly twice as much energy when hovering in place compared to resting.

The study, led by scientists at the University of California San Diego’s Scripps Institution of Oceanography, also details the biomechanics of fish hovering, which includes constant, subtle fin movements to prevent tipping, drifting or rolling. This more robust understanding of how fish actively maintain their position could inform the design of underwater robots or drones facing similar challenges.

The findings, published on July 7 in the Proceedings of the National Academy of Sciences, overturn the long-standing assumption in the scientific literature that maintaining a stationary position in water is virtually effortless for fish with swim bladders. The reason for this assumption was that nearly all bony fishes have gas-filled sacs called swim bladders that allow them to achieve neutral buoyancy — neither sinking nor rising to the surface. The presence of a swim bladder and the stillness of hovering fish caused the research community to assume hovering was a form of rest that was easy for fish to maintain.

Prior research from lead study author and Scripps marine biologist Valentina Di Santo found that the energy required for skates to swim at various speeds followed a distinct U-shaped curve, with slow and fast swimming requiring the most energy and intermediate speeds being the most energy-efficient. Based on these findings, Di Santo suspected there might be more to hovering than meets the eye.

To learn more, Di Santo and her co-authors conducted experiments with 13 species of fishes with swim bladders. The team placed each fish in a specialized tank and recorded their oxygen consumption during active hovering and motionless resting (when the fish supports its weight with the bottom of the tank). While the fish were hovering, the researchers filmed them with high-speed cameras to capture their fin movements, tracking how each fin moved and how frequently they beat.

The researchers also took a variety of measurements of each fish’s body size and shape. In particular, the scientists measured the physical separation between the fish’s center of mass, which is determined by weight distribution, and its center of buoyancy, which is related to the shape and location of its swim bladder. All these measurements provided a way to quantify how stable or unstable each fish was.

The study found that, contrary to previous assumptions, hovering burns roughly twice as much energy as resting. “Hovering is a bit like trying to balance on a bicycle that’s not moving,” said Di Santo.

Despite having swim bladders that make them nearly weightless, fish are inherently unstable because their center of mass and center of buoyancy don’t align perfectly. This separation creates a tendency to tip and roll, forcing fish to make continuous adjustments with their fins to maintain position. The study found that species with greater separation between their centers of mass and buoyancy used more energy when hovering. This suggests that counteracting instability is one of the factors driving the energy expended during hovering.

“What struck me was how superbly all these fishes maintain a stable posture, despite their intrinsic instability,” said Di Santo.

A fish’s shape and the position of its pectoral fins also influenced its hovering efficiency. Fish with pectoral fins farther back on their body were generally able to burn less energy while hovering, which Di Santo suggested may be due to improved leverage. Long, slender fish, such as the shell dweller cichlid (Lamprologus ocellatus) and the angelfish (Pterophyllum scalare), were found to be less efficient hoverers compared to more compact species like the guppy (Poecilia reticulata) and the zebrafish (Danio rerio).

The study’s findings have significant implications for the design of underwater robots. “By studying how fish achieve this balance, we can gain powerful design principles for building more efficient, responsive underwater technologies,” said Di Santo.

In particular, the findings could help improve the maneuverability of underwater robots, which could allow them to access and explore complex, hard-to-navigate environments like coral reefs or shipwrecks. According to Di Santo, underwater robots have historically been designed with compact shapes that make them stable. As in fish, shapes with more built-in stability are less maneuverable.

“If you want a robot that can maneuver through tight spaces, you might have to learn from these fishes to design in some instability and then add systems that can dynamically maintain stability when needed,” said Di Santo.

The study was co-authored by Xuewei Qi of Stockholm University, Fidji Berio of Scripps Oceanography, Angela Albi of Stockholm University, the Max Planck Institute of Animal Behavior, and the University of Konstanz, and Otar Akanyeti of Aberystwyth University in Wales. The research was supported by the Swedish Research Council, the European Commission, the Stockholm University Brain Imaging Centre and the Whitman Scientist Program at the Marine Biological Laboratory.