President recognizes legacy
of Nelson Mandela on his death


President Laura Chinchilla Miranda has joined other world leaders in mourning the death of Nelson Mandela.

Casa Presidencial quoted the president expressing her condolences to the South African people and especially to Mandela's wife, Graca Machel.

"Today the world says good-by to Nelson Mandela, a leader who with his determination and ideals managed to liberate his people from oppression and injustice," said Ms. Chinchilla.  "A tireless fighter from the rights of the oppressed, the world mourns the absence of this Nobel laureate."

Ms. Chinchilla also pointed out that Fernando Volio, who died in 1996, was Costa Rican ambassador to the United Nations and he managed to get the world body to favor Mandela in his fight against apartheid and the white ruling class of South Africa.

Mandela’s life spanned more than nine decades, and he steered the nation out of its darkest days under the racist apartheid regime to the exuberant, democratic Rainbow Nation it is today. 

The news of his death came as no surprise. Mandela had been in and out of the hospital for much of this year, and the 95-year-old had lived a challenging and stressful life.
 
Mandela was once a young firebrand leader of the then-banned African National Congress, which opposed the racist, white-led apartheid regime.   Mandela led the group’s armed wing, an act that landed him in prison for 27 years.

Those were his, and South Africa’s, darkest days.
 
But the charismatic Mandela managed to keep his resolve and lead his struggle from his jail cell.  He emerged triumphant, having helped bring down apartheid and being elected president in the nation’s first all-inclusive elections in 1994.
 
He served but one presidential term, but it is for his lifelong struggle that he will be remembered, as a fighter and a prisoner turned statesman and peacemaker.

The task of telling the world of his death fell to President Jacob Zuma, a normally jovial leader who could not keep the sadness from his voice as he described the man so many South Africans consider the father of their nation.
 
"Our thoughts are with the millions of people across the world who embraced Madiba as their own and who saw his cause as their cause.  Our nation has lost his greatest son," he said. "Yet what made Nelson Mandela great was precisely what made him human.  We saw in him what we seek in ourselves and in him we saw so much of ourselves."  Madiba was Mandela's tribal name.


Male dancers are sought
for 2014 season performances


The Compañía Nacional de Danza is looking for a few good men.

The Ministerio de Cultura y Juventud said that dancers between the ages of 18 and 35 were being sought to fill out the male ranks of the company. Sought by the company are professional and advanced students for the 2014 season.

Resumes are being accepted until 4:30 p.m. today at the Centro Nacional de la Cultura on Avenida 7. Auditions are Saturday.

Those who apply should have knowledge of contemporary dance and classical ballet. They should be prepared to participate in national and international tours, said the ministry. Rehearsals and training start Jan. 13, the ministry said.


Minister got valve replaced
at hospital in Houston, Texas


Edgar Ayales, the minister of Hacienda, is recuperating after heart surgery in Houston, Texas, earlier this week.

The ministry, which handled the nation's finances, released more information on the minister Thursday. The surgery was to replace a value in the aorta, the ministry said.

The surgeon in the case is David Paniagua, a Costa Rican, said the report. He is a cardiologist on the staff of St. Luke's Medical Center in Houston, but the ministry did not say where the surgery was performed.

The minster is expected to return to Costa Rica next week but will not be on the job again until January, the ministry said Monday.


Pleasant-smelling compounds
found to block, lure mosquitoes


Female mosquitoes, which can transmit deadly diseases like malaria, dengue fever, West Nile virus and filariasis, are attracted to humans by smelling the exhaled carbon dioxide. They are capable of tracking a person down even from a distance.  But once they get close, they often steer away toward exposed areas such as ankles and feet, being drawn there by skin odors.

Why does the mosquito change its track and fly towards skin?  How does it detect the skin?  What are the odors from skin that it detects? And can the mosquito skin odor sensors be blocked and reduce attractiveness?

Recent research done by scientists at the University of California, Riverside can now help address these questions.  They report on Dec. 5 in the journal Cell that the very receptors in the mosquito’s maxillary palp that detect carbon dioxide are ones that detect skin odors as well, thus explaining why mosquitoes are attracted to skin odor — smelly socks, worn clothes, bedding — even in the absence of carbon dioxide.

“It was a real surprise when we found that the mosquito’s CO2 receptor neuron, designated cpA, is an extremely sensitive detector of several skin odorants as well, and is, in fact, far more sensitive to some of these odor molecules as compared to CO2,” said Anandasankar Ray, an associate professor in the Department of Entomology and the project’s principal investigator. “For many years we had primarily focused on the complex antennae of mosquitoes for our search for human-skin odor receptors, and ignored the simpler maxillary palp organs.”

Until now, which mosquito olfactory neurons were required for attraction to skin odor remained a mystery.  The new finding that the CO2-sensitive olfactory neuron is also a sensitive detector of human skin is critical not only for understanding the basis of the mosquito’s host attraction and host preference but also because it identifies this dual receptor of CO2 and skin-odorants as a key target that could be useful to disrupt host-seeking behavior and thus aid in the control of disease transmission.

To test whether cpA activation by human odor is important for attraction, the researchers devised a novel chemical-based strategy to shut down the activity of cpA in Aedes aegypti, the dengue-spreading mosquito.  They then tested the mosquito’s behavior on human foot odor — specifically, on a dish of foot odor-laden beads placed in an experimental wind tunnel — and found the mosquito’s attraction to the odor was greatly reduced.

Next, using a chemical computational method they developed, the researchers screened nearly half a million compounds. They then short-listed 138 compounds based on desirable characteristics such as smell, safety, cost and whether these occurred naturally. Several compounds either inhibited or activated cpA neurons of which nearly 85 percent were already approved for use as flavor, fragrance or cosmetic agents. Better still, several were pleasant-smelling, such as minty, raspberry, chocolate, etc., increasing their value for practical use in mosquito control.

Confident that they were on the right track, the researchers then zeroed in on two compounds: ethyl pyruvate, a fruity-scented cpA inhibitor, approved as a flavor agent in food, and cyclopentanone, a minty-smelling cpA activator approved as a flavor and fragrance agent.  By inhibiting the cpA neuron, ethyl pyruvate was found in their experiments to substantially reduce the mosquito’s attraction towards a human arm. By activating the cpA neuron, cyclopentanone served as a powerful lure, like CO2, attracting mosquitoes to a trap.

“Such compounds can play a significant role in the control of mosquito-borne diseases and open up very realistic possibilities of developing ways to use simple, natural, affordable and pleasant odors to prevent mosquitoes from finding humans,” Ray said.  “Odors that block this dual-receptor for CO2 and skin odor can be used as a way to mask us from mosquitoes.  On the other hand, odors that can act as attractants can be used to lure mosquitoes away from us into traps.  These potentially affordable mask and pull strategies could be used in a complementary manner, offering an ideal solution and much needed relief to people in Africa, Asia and South America — indeed wherever mosquito-borne diseases are endemic.  Further, these compounds could be developed into products that protect not just one individual at a time but larger areas, and need not have to be directly applied on the skin.”

Currently, CO2 is the primary lure in mosquito traps. Generating CO2 requires burning fuel, evaporating dry ice, releasing compressed gas or fermentation of sugar — all of which is expensive, cumbersome, and impractical for use in developing countries.  Compounds identified in this study, like cyclopentanone, offer a safe, affordable and convenient alternative that can finally work with surveillance and control traps.