Dec 12, 2016

What is Melanin ?

Melanin is a type of protein produced in melanocytes from an essential amino acid called tyrosine. This protein is primarily responsible for coloring the skin and skin of humans, as well as protecting the DNA from the cells against ultraviolet radiation emitted by the sun.

Melanocytes are derived from melanoblasts and are located in the epidermis, more precisely in the germ stratum. They are globule shaped, which is where protruding extensions extend towards the most superficial region of the epidermis (see figure above). These extensions enter into cells known as keratinocytes, where they release the melanin and form the epidermal-melanic unit. It is worth emphasizing that a melanocyte can interact with more than thirty different keratinocytes.

Within the melanocytes, there are elliptic organelles called melanosomes. It is in these structures that melanin is produced. The more melanocytes the melanocytes have, the more pigmented a person's skin is. It is worth stressing that people who have a genetic disease called albinism are unable to synthesize melanin.

There are two main types of melanin: eumelanin and pheomelanin. The first presents a coloration that varies from black to brown, in addition to having a high molecular weight and ability to disperse ultraviolet light. Feomelanin shows coloration ranging from red to yellow.

When we are exposed to the sun, we observe the darkening of our skin, an occurrence that is a way to protect our DNA. At this time, increased production of a type of melanin called facultative melanin is observed. Facultative melanin is produced only when exposure to ultraviolet rays occurs. In contrast, there is a type of melanin that is produced thanks to the action of our genes: constructive melanin. In view of this, it is easy to understand that tanning is achieved thanks to the production of facultative melanin, while our actual skin color is a result of constructive melanin.

Although our body has melanin as a form of protection against ultraviolet rays, exaggerated exposure to the sun can trigger serious problems such as burns, premature aging and skin cancers.

By Ma. Vanessa dos Santos

Donald Trump names allies and children for transition team


Trump's company says that naming children is not a conflict of interest.

Vice Mike Pence was tasked to lead government transition team.

 

Reuters
11/11/2016 9:02 PM - Updated 11/11/2016 9:33 PM
Donald Trump names allies and children for transition team
Trump's company says that naming children is not a conflict of interest.
Vice Mike Pence was tasked to lead government transition team.
From the G1 in São Paulo

US President-elect Donald Trump has appointed Vice President Mike Pence, a White House transition team who also includes three of his eldest sons, on Friday (11), when the Administrative positions.

According to Trump's campaign, Pence replaces New Jersey Governor Chris Christie, who remains the vice president of the transition effort, at a time when he deals with the aftermath of a scandal that has affected his political stance.

As reported by Reuters, the announcement came shortly after Trump's aides gathered at the Trump Tower in New York to begin assessing candidates for some of the 4,000 vacancies he will have to fill soon after taking office on January 20 2017.

Trump relied on a small circle of allies and family members during a difficult presidential campaign. These people will continue to play an important role in the transition, according to the announcement.

Trump's daughter, Ivanka, and sons Eric and Donald Jr., along with son-in-law Jared Kushner, have been appointed as transition team members, although they have to oversee their business empire. Trump's company said the arrangement would not violate the conflict
of interest laws.

 


Bayern vs. Arsenal in the eighth round of the Champions League



The draw defines duels of the first knockout phase of the main European club tournament. Other clashes will be Dortmund vs. Benfica, Leverkusen vs. Atletico Madrid, Barcelona vs. PSG, Real Madrid vs. Napoli. The draw for the last 16 of the Champions League of Europe, held on Monday (12/12), put the Bayern Munich again face-to-face with England's Arsenal. Both teams have already faced each other in the same phase of the tournament in 2005, 2013 and 2014, with the Germans coming out winners on all occasions.

 This will be the first challenge of the Bavarian team in the knockout stage of the main European club tournament under the command of Italian Carlo Ancelotti, who has already won the competition twice. With his predecessor, Pep Guardiola, Bayern were eliminated in the semifinals of the last edition of the Champions League by Atletico Madrid.

 Ancelotti predicts "two interesting games", emphasizing that his team will need to be in the best form in the first home game against the "Gunners" to have chances of qualifying in the decisive game in London.

"Arsenal have a very good team today and a coach that I respect a lot," said the Italian. "They are doing well in the Premier League and have lost only one league game this year. It will be difficult, but I am confident."


 Bayern, who have reached three consecutive semi-finals after winning the European title in 2013, managed to avoid a direct confrontation with Neymar's Barcelona and Messi, who will face Paris Saint-Germain. The French were defeated by the Catalans in the quarterfinals of the League on two occasions in 2013 and 2014.

Borussia Dortmund will face Benfica while Bayer Leverkusen take on Atletico Madrid. Real Madrid, defending champion, will defend the title against Napoli, Italy. The draw also defined the duels between Juventus and Porto, Sevilla and Leicester City, as well as Manchester City and Monaco.

 The first round of the Round of 16 will be on the 14th, 15th, 21st and 22nd of February. The games that will decide to qualify for the next phase will take place on 7, 8, 14 and 15 March.

Check out the duels of the octaves of the Champions League of Europe:

Benfica (Portugal) vs. Borussia Dortmund (Germany)

Bayern Munich (Germany) Vs. Arsenal (England)

Bayer Leverkusen (Germany) Vs. Atletico Madrid (Spain)

Manchester City (England) Vs. AS Monaco (France)

Real Madrid (Spain) vs Napoli (Italy)

Porto (Portugal) vs. Juventus (Italy)

Paris Saint-Germain (France) Vs. Barcelona, Spain)

Sevilla (Spain) vs. Leicester City (England)

RC / dpa / rtr / dw


Angkor Wat - The Wonder of the Forgotten World

Angkor Wat - The Wonder of the Forgotten World

 On 07/07/07, the new seven wonders of the World were announced in Lisbon, the result of a "contest" that was not supported by UNESCO. Angkor Wat was left out. But for those who have visited this ruins complex, it is clear that it deserves a place in the "7 wonders", especially if we compare it to one of the winners (I will not reveal which, so as not to hurt susceptibilities ...).





 Contests aside, the Angkor complex, which stretches for about 200 km2 in northwestern Cambodia, is one of the most impressive archaeological sites on the planet. At present, from entire cities, capitals of empires built over centuries, there remain only the ruins of temples built in stone (unlike houses, palaces and other structures), dedicated to the Hindu and Buddhist gods. After the height of the Khmer empire (not to be confused with the so-called "red Khmer" of the 20th century ...) XII and XIII, Angkor was sacked several times and fell into oblivion until the 18th century. XX. The ruins are generally quite run down, but given the centuries that have passed and the recent violent and bloody history of Cambodia, it is even surprising what has come down to the present day. And it is these ruins that today constitute one of the most important sources of revenue for a fragile and needy country.




 Given the extent and complexity of Angkor, we decided to buy the three-day ticket and thus sleep four nights in Siem Reap, the city a few miles away. On the first day, we chose to visit the main attractions, which are also those that are closer to the city. So we decided to leave the rickshaw for the other days and go cycling, so that we can stop whenever and wherever we want, and we can better "absorb" the surrounding landscape. It proved to be an excellent choice. The weather was very cloudy all day (bad for the photos!) But it did not rain (good for cyclists!). On the second and third days we visited other temples, some of them quite interesting, such as the temples of Banteai Srey (with exceptional stone decoration) and Bakong (the first mountain-shaped temple, further away from the city but worth to be Visited), but none of them approaching the grandeur and beauty of those we visited on the first day.









 Angkor Wat, the largest religious complex in the world and main attraction of Angkor, was our first stop. It did not impress us much initially, perhaps by the immense number of tourists present (and this was the low season!), By the lack of sun or by very high expectations. The next day, we would return to Angkor Wat by the end of the afternoon, already with sun, and the temple had already looked like another. Even so, personally, I thought it was more elaborate (save the low reliefs that survived in the galleries) and was better preserved, especially the towers of the central sanctuary, which are the "face" of this temple.







 The moat could also be better taken care of, which would greatly increase the quality of the views of the complex from the outer banks. That said, the scale and complexity of the complex are second to none. It's a shame not to have money for a balloon ride ...





 In my opinion, the true pearl of Angkor is situated a few kilometers to the side. Angkor Thom was, at the end of the century, XII, the largest city the Khmer empire and today we can admire the ruins of the main temple of the city, its name Bayon. Although it contains some of the most beautiful bas-reliefs of Angkor, the landmark image of this temple is undoubtedly the set of 54 towers and 216 stone carvings that tower above each of the towers. Four faces with an enigmatic smile, contemplating the four cardinal points, and thought to represent the bodhisattva Avalokitesvara, personified by the king-god Jayavarman VII, who had the city constructed. The originality of the building and the serenity transmitted by the faces in stone (especially when the crowds of tourists leave ...) guarantee this temple a unique place in the history of architecture. Let's hope it stays that way for many years!




 We also visit Phnom Bakheng, which stands on a hill above the surrounding plain, and from where you get fabulous views of the forest that seems to be able to cover all temples at any time. From avoiding, however, to the sunset, since it is the final destination of all day tour packages ... A tourist circus!




 Finally, to highlight the temple of Ta Prohm, famous for the trees that embrace the ruins with its roots, creating a spectacular and enigmatic effect, so much that was already used by Hollywood in the films of Lara Croft, starring Angelina Jolie. Could the beauty of this temple (apart from the countless beautiful Cambodian children surrounding temples selling souvenirs to tourists) have contributed to the actress's heart opening to Cambodia and humanitarian causes? ... (Perhaps our Guterres may ask you!)