HAVANA - As the United States and Cuba fire accusations at each other in the latest tumultuous chapter in their conflictive relationship, some members of U.S. scientific and student communities are working to salvage exchanges between the two nations.

Professor Charles Verharen, of the Washington-based Howard University, told IPS that these kinds of bilateral relationships are "indispensable; communication among academics is a prerequisite for building a theoretical foundation through which the two countries can begin to bridge their gap."

The expert is involved in a study on bringing post-secondary education to Cuba"s neighbourhoods, using channels of teaching outside of the traditional campuses to make university education available to the masses.

Verharen says that, "political, economic, social and -- most importantly -- philosophical understanding and reconciliation between the two countries is impossible" without this kind of engagement.

The tense relations between Havana and Washington deteriorated even further early this month, when the United States Interests Section in Havana accused authorities of harassment, reporting cut-offs of water and electricity to the office.

The Cuban government responded with an editorial in the local press, accusing Washington"s representatives of searching for pretexts to once and for all put an end to what little relations are left between the two countries.

Verharen noted that "it is getting harder" for U.S. citizens who want to visit the island nation, and said his status as a researcher is the only reason he was able to get to Cuba.

However, he did not hide his concern that "it is likely that the conservative George W. Bush administration will go so far as to prohibit this kind of academic exchange."

In May, according to U.S. press reports, Bush postponed an announcement of new measures for stricter travel bans for academics and religious delegations.

In March 2003 the U.S. government suspended permits for educational exchanges, and in May 2004 further tightened restrictions for all visa categories.

Allison Hayes-Conroy, a graduate student in cultural and political geography, is in Havana making "contacts for a research project" in the food and agriculture sector.

She explained to IPS that, while she has been allowed to travel from her city, Philadelphia, Pennsylvania, to Cuba to take care of the initial research for her study, "I am worried, because I don"t know if I"ll be able to come back, and that"s just not fair."

The researcher called the Cuba travel restrictions "terrible," because "it is very important for both professors and students to interact and trade knowledge" with the Cuban community.

Hayes-Conroy said studying "the relationship between agriculture, food and Cuba"s situation over the past 10 years has been fascinating," and that the results "could be of use to people in the United States."

Doctor of sociology Jualynne Dodson, a professor at Michigan State University, is currently conducting a field study in Cuba. She defends "the free flow of ideas and information" fostered by her country"s academic institutions.

In an interview with IPS, she commented on U.S. policy regarding religious exchanges between the countries, which she sees as favouring some groups over others.

"The government decides who gets a permit" to travel to Cuba for religious reasons, said Dodson. "U.S. religious organisations, such as the National Council of Churches (NCC), were denied" permits last year.

In 2005 the NCC and the Church World Service, along with four additional Protestant organisations, were informed by the U.S. Treasury Department"s Office of Foreign Assets Control that their permits for religious travel to Cuba would not be renewed.

Dodson recalled meeting, in the western Cuban province of Pinar del Río, "a group of young missionaries from (the U.S. state of) Florida," who, in her opinion "are less interested in evangelising than in distributing money and material goods to the rural poor."

Although "they come as missionaries," these youth "divide the Cuban people, and yet many have received permits for their religious work," she said.

Reverend Raúl Suárez, when contacted by IPS, confirmed the presence of "about 70 of these kinds of U.S. groups, who enter on tourist visas," and who have "worked throughout the country, although they are focused most in the eastern regions."

Dodson added that current regulations on Cuban exchanges are already "very tough," but a related law passed by the Florida senate "will have many negative consequences."

On May 3, Florida"s state legislature approved the Travel to Terrorist States Act, signed into law by Governor Jeb Bush May 30, which bans state universities from funding travel to Cuba and four other countries.

Dodson believes the law is a mistake, because "politics should not begin to dictate what universities should do."

Professor and lawyer Mark Kruger, of Saint Louis University, said he worries that "the federal government might do the same thing."

The academic is conducting a comparative study between the two countries" civil societies and mass organisations, and told IPS that one of the groups has launched a legal challenge to Florida"s new law.

The academics will make their case to the U.S. government that travel to Cuba for educational and academic purposes is a right, said Kruger.

Also, on Jun. 13, the American Civil Liberties Union filed a lawsuit in a federal court in Miami claiming that the restrictions imposed by the law are unconstitutional, as they encroach on federal foreign-policy jurisdiction.

"We are not going to let this go without a fight in the United States -- we are not going to give up these exchanges," he concluded.