A new study on plant reproduction finds that developing cells are very affected by altered states of gravity—a finding that has implications for our hopes for a future human society in space.
In order for plants to have sex, a pollen grain first lands on a stigma (the female part of a flowering plant.) Following a chemical come-hither signal from the stigma, the pollen grain grows a pollen tube, a tunnel for sperm cells to travel down to reach the egg for fertilization. Pollen tubes are the fastest growing cells in the plant kingdom. The pollen tube was used as a model system for a recent study on the effects of altered gravity on plant reproduction because a response in the pollen tube takes a matter of mere seconds. Read More
A plant’s sap is responsible for transporting sugars from the site of their manufacture (the leaves) to growth centers (further up the branch or trunk of the plant). And the system has to strike a delicate balance: if the sap has a low concentration of sugars, there isn’t much energy flowing to the plant; if, on the other hand, there are lots of sugars in the sap it becomes too thick to pump efficiently. It’s a situation a lot like transporting any payload through a traffic artery, be that a paved highway or a canal with kayakers. So what’s in a plant’s best interest?
Scientists have recently found that a key ingredient in bee venom destroys HIV without harming other cells. The researchers loaded the toxin, called mellitin, onto nanoparticles fashioned with “bumpers” that normal, larger cells bounced off of unharmed. HIV is small enough that it fits between the bumpers and makes contact with the surface of the nanoparticles, where the bee toxin awaits. Melittin on the nanoparticle fuses with the viral envelope and ruptures it, stripping the virus’s shell.
Research published last week in Nature appears to add another point to the controversial argument that viruses might be living creatures. Scientists at Tufts University School of Medicine have found a virus that captures its host’s immune system and uses it to destroy the host.
In order to be deemed a real “living creature”, an organism needs to have a genome, be able to grow and make more of itself by replication, and be capable of evolving, or adapting to its environment over successive generations. Humans are living creatures, as we exhibit all of those capacities.
For a long time, scientists have deemed viruses, which are little packages of infective material that can only replicate inside living organisms, to be primitive particles of DNA and RNA, termed a “biological entity.” Thus, not living.
We tend to think that atherosclerosis, the hardening and narrowing of arteries leading to stroke and heart attacks, is a modern condition, the result of the modern diet, smoking, and obesity. We’re often encouraged to return to traditional diets, or, to “eat like our grandmothers”, because presumably before processed foods people ate healthier. But a study released yesterday (pdf) assessed 137 mummies from different cultures and found that across vast periods of time and geographic space, ancient people also suffered from this disease, and as humans we might be more predisposed to it than we’d thought.
The researchers studied mummies from different times in four different geographical regions, including ancient Egypt, ancient Peru, Southwest America, and the Aleutian Islands in Alaska, and found that over a third of the mummies studied exhibited signs of atherosclerosis. Even where arteries had long since disintegrated with decay of the body, the calcified parts of the walls remained. The scientists found that age at time of death was correlated with the presence and severity of atherosclerosis in the mummies in question. Read More
Just like dissection can reveal important information about animal structure and morphology, so can attempting to recreate and mimic aspects of animals with robotics.
That’s the approach of a group of researchers at Brown University, who have developed a robotic wing to mimic a bat wing in flight. They are using this wing to measure the aerodynamics of a bat’s flight, results which may someday help us build better flying machines.
Bats have very different wings than flying insects and birds, and their wings are correspondingly more structurally complex. Bat wings make their owners capable of commuting and migrating long distances, carrying heavy loads, flying fast, and being able to fly in narrow spaces like between trees.
The giraffe is in some ways a perfect symbol for evolution: they eat the leaves of tall trees, and they have the longest necks you can imagine as a result. But how has the rest of their body responded to their massive size?
In a rat, things happen quickly, as you can imagine based on their size. They sense and respond to stimuli with the characteristic jerky little movements we’ve all observed. They embody the types of sensorimotor control (an animal’s ability to take in outside information and respond appropriately) that all animals execute in order to survive, and they’re an efficient little package at doing so.
Bigger animals are less so. Nerves must travel longer distances in bigger animals–for instance, each giraffe sciatic nerve, which runs down each of its legs, is several yards long. If nerve signals in the giraffe go only as fast as those in the rat, giraffes would be expected to be much clumsier.
Thus a group of researchers decided to study whether giraffes have sensorimotor adaptations to their massive size. Could they have a special nervous system setup that somehow fast tracks messages along their very long nerve and muscle fibers?
Physicists announced last week that the Higgs Boson is light enough to make the Universe unstable, and predicted its catastrophic demise for several billion years from today.
Last summer, scientists finally found the long awaited Higgs Boson, a particle that, according to theoretical physics, gives all elementary particles mass. Without the Higgs, these particles would remain massless, and our bodies, blankets, cups of tea, dogs, and universe wouldn’t exist.
The Higgs particle is part of an equation that predicts the stability of the Universe, and now that we’ve found it, physicists can finally make calculations with that formula. For the Universe to maintain stability long term, the Higgs should weigh about 129 GEV. What they’re finding is that the Higgs is a bit on the light side, capping out at 126 GEV, and when that light weight is plugged into the equation—explosive universal demise ensues. Read More
By isolating 150 flower species against white, and flooding them with light in the height of their blossom, for his recent book Flowers photographer Andrew Zuckerman sought to make individual “portraits” of the botanicals. Read more >>
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