Tuesday, July 31, 2018

Normal bees and killer bees



turning normal bees into killer bees
Africanized bees, commonly known as "killer bees", are much more aggressive than their European counterparts. Now, a team of researchers have examined the changes in neuropeptides that take place in the brains of these bees during their aggressive behavior and have shown that they can turn normal bees into 'killer' by injecting certain peptides.

Only a few neuropeptides make the difference between a honey bee and another that has an irritable need to wipe out everything that moves.

To discover what it is that makes Africanized "killer bees" so hostile, the State scientists at the University of São Paulo (Brazil) compared their neurochemistry with that of their more docile relatives and found that it is mostly due to a surprisingly simple chemical change.

The reputation of killer bees is well deserved. Its venom is no more lethal than average honey bees and they are even a little smaller, but they are incredibly aggressive, and it does not take much provocation to incite a swarm of these bees to become a furious and poignant pain machine.



The more hostile an animal is, the more caution you have to have

These bad-tempered striped insects appeared in the late 1950s, after Brazilian beekeepers imported an African variety of Apis mellifera scutellata in order to increase honey production. It seems that the bees did not understand the fine print very well and ended up paying for the honey bees.

Since then, these aggressive hybrids have spread to northern California and remain a legitimate threat. Several hundred people have lost their lives due to their implacable twinge. And is that this subspecies is also extremely sensitive to the presence of humans. They usually attack the eyes and the face, and the only thing that can be done before them is to run away.

But what happens in your brain to act in this way?

To get to the bottom of the mystery, the researchers of this last study had to collect a sample of killer bees (something not without danger). Using a rather curious trick they managed to catch them to observe their tiny brains.

The comparison of the full range of brain proteins from two bee samples using mass spectral imaging revealed a clear, but simple difference.

One of the suspected proteins was called Apis mellifera Allatostatins A, a neuroprotein that is already known to play a key role in the learning and memory of bees, as well as in their overall development.

The other group of proteins, described as tachykinin-related peptides, seems to influence sensory processing.

In aggressive hybrids, these two groups of neuropeptides had been cut into shorter proteins, and found in different groups of brain tissue called neuropiles.

To verify that these proteins were significant in the transformation of the behavior of the bee, the scientists injected in the brain of a group of non-aggressive bees truncated forms of these neuropeptides.

As expected, the bees did not seem very happy when they woke up, because having modified their brain chemistry they had also become killer bees.

However, it is still unknown why the size and distribution of these neuropeptides lead to such aggressive behavior. Learning more about the cascade of effects that these proteins have on the nervous system of a bee could tell us more about the development of the nervous systems of bees, as well as those of insects in general.


Saturday, July 21, 2018

Curiosities about polar bears



The lion is par excellence the king of the jungle, but if we change the scenery and drastically lower temperatures, the polar bear becomes, without any doubt, the new and legitimate monarch.

These amazing creatures inhabit the waters covered by the Arctic ice, extending from Canada, Norway or Denmark, to some areas of Russia and even, to a lesser extent, in Iceland. This causes that the idea that the polar bears unfold with great ease in adverse conditions and extremely dangerous for any other type of living being is reaffirmed.

It is estimated that there are currently between 22,000 and 32,000 copies worldwide, indices that, due to their progressive decline, have awakened for years the concern of biologists and scientists. In fact, this species has become the reference for the health status of ecosystems. Unfortunately, the extreme situation of polar bears is a powerful indicator of the lack of effective environmental policies worldwide.

For more than twenty years, polar bears have been forced (and increasingly) to travel long distances during the summer periods in search of frozen areas. Precisely, it is the ice that depends on obtaining food from these animals, because it is what allows them to hunt. The rise of temperatures delays the solidification of the water and therefore, delay (and shorten) the feeding period of the bears. Unfortunately, it is increasingly common to find these animals in a serious state of malnutrition. The most prone to this are the females with puppies that inhabit the areas further south of their range.

Organizations such as the Oceanic Administration of the USA have carried out different research on the environmental impact of the melting of the Arctic plates. The latest results have been alarming, since 2016 recorded the smallest sea ice surface in the last 37 years.

Despite the difficulties, the polar bear is still one of the most impressive creatures on the planet, as its characteristics make it an icon of the animal kingdom. In the next gallery we show you everything you need to know about this vulnerable, but powerful species.


Evolution

The polar bear (Ursus maritimus) evolved from a population of brown bears during the Pleistocene. Some research suggests that this process began about 38 million years ago, when a large group of bears separated and adapted to new living conditions.


800 kilos

It is the largest terrestrial animal. It measures up to 3 meters from the snout at the end of the tail, and weighs up to 800 kilograms (the male). However, they have relatively small heads.


Family of 3

The polar bears have two young per litter after a gestation period of 6.5 to 9 months. The young remain with the mother for 2 or 3 years. The rest of the time, they are solitary animals.


Tireless travelers

The polar bear can travel up to 1000 kilometers in the changing seasons, when the ice melts or freezes, either walking on the ice or swimming. His nose is so sharp that he can smell a seal 32 kilometers away.


Black under a white coat

Under the white fur, the polar bear's skin is black, which helps him absorb the sun's rays. In addition, it has a thick layer of grease to withstand polar temperatures. Its double fur coat repels water and, thanks to its white color, helps it to camouflage itself.


At 37 degrees

The polar bears, in addition, maintain an average temperature of 37 degrees. The reason why they endure extreme temperatures is that in addition to their thick and hard skin layer, these animals have a thick layer of extra fat. This is the cause of its thermoregulation. However, that same layer is what causes them to have a rapid overheating and can not withstand high temperatures.


Lazy

Polar bears are inactive most of the time (66.6% of their lives). Overheating is one of the main factors by which this species moves at a low speed and usually lie down to rest.


Playing live more

The polar bears that play live longer, enjoy better health and have more offspring, according to a recent study by the ethologist Robert Fagan of the University of Alaska.


A great smell

One of the most developed senses of the polar bear is its smell. It is so sharp that you can smell the seal of a seal more than 30 kilometers away, something very useful considering the difficulties to find food. In addition, it is very important to identify any type of danger that may lurk around you.



Feeding

They can eat up to 30 kilos of food in the same day. Its main source of food are seals. They have 42 sharp teeth, which allow them to easily devour their prey. These pieces are longer than those that the brown bear has in its mouth.


They dive

Sometimes, when stalking their prey, the polar bears are submerged in the water thanks to the adaptations of their legs. This activity is also performed to find algae, cleanse or reduce body temperature. It is estimated that they can remain submerged for 2 minutes at depths between 3 and 5 meters.


Always clean

This species is extremely clean, because after hunting and devour their prey, always spend time to remove with water and snow the remains of the animal in your body. Researchers suggest that, because they are so sensitive to smell, they are uncomfortable with the smell and need to remove it immediately.


Satellite tracking

WWF and Canon have developed the online tool (Polar Bear Tracker) that allows us to follow their migratory movements in the archipelago of Svalbard, Norway, the Sea of ​​Beaufort, Alaska, the Bay of Hudson and Canada. The use of collars with satellite devices helps to closely monitor their movements, expand knowledge of their habits and know how they are affecting the impacts of climate change.


In danger

The polar bear is listed as a vulnerable species in the Red List of Endangered Species of the International Union for Conservation of Nature. According to reports from the World Wildlife Fund, these creatures could disappear during the next century if the destruction of their ecosystem is not stopped.