Saturday, November 07, 2009
The Pig
Diana Yates, Life Sciences Editor University of Illinois,Urbana-Champaign November 2, 2009)
First Draft Of The Pig: Researchers Sequence Swine Genome
A global collaborative has produced a first draft of the genome of a domesticated pig, an achievement that will lead to insights in agriculture, medicine, conservation and evolution.
A red-haired Duroc pig from a farm at the University of Illinois will now be among the growing list of domesticated animals that have had their genomes sequenced. Researchers announced the achievement at a meeting at the Wellcome Trust Sanger Institute in Hinxton, England.
"The pig is a unique animal that is important for food and that is used as an animal model for human disease," said Larry Schook, a University of Illinois professor of biomedical sciences and leader of the sequencing project. "And because the native wild animals are still in existence, it is a really exciting animal to look at to learn about the genomic effects of domestication," he said.
The Duroc is one of five major breeds used in pork production around the world and is one of about 200 breeds of domesticated pigs. There are also numerous varieties of wild boar, the non-domesticated pigs that are believed to have originated in Eurasia.
The sequencing project involved an international team of scientists and genome-sequencing centers. The USDA National Institute of Food and Agriculture, formerly the Cooperative State Research, Education and Extension Service, provided $10 million in initial funding, requiring that this be the only pig genome-sequencing project in the world, that it be a public-private partnership and a global collaborative effort, with significant financial or in-kind support from the other participating agencies and stakeholders.
The effort cost about $24.3 million, with additional support from the USDA Agricultural Research Service and many other American, Asian and European funders. A requirement of participation was that the findings be made public, with no proprietary interests allowed.
The draft sequence, which is about 98 percent complete, will allow researchers to pinpoint genes that are useful to pork production or are involved in immunity or other important physiological processes in the pig. It will enhance breeding practices, offer insight into diseases that afflict pigs (and, sometimes, also humans) and will assist in efforts to preserve the global heritage of rare, endangered and wild pigs. It also will be important for the study of human health because pigs are very similar to humans in their physiology, behavior and nutritional needs.
Link to Wellcome Trust Sanger Institute
Link to U. Illinois news release
Coercion and sanctions fail
Science Daily (November 4, 2009)
Poor Start Between A Class And Its Teacher Almost Impossible To Rectify
The relationship between a teacher and class is important for the learning achievement of pupils and their pleasure in learning. Dutch researcher Tim Mainhard discovered that these teacher-class relationships are very stable over the course of a school year. Consequently if teachers get off to a bad start, it is almost impossible to put things right.
During four studies in high school classes, Mainhard observed pupils and asked them to complete questionnaires under different circumstances and at different times. Teacher-class relationships were found to be pretty stable. And if they did change then the relationship over the course of a school year was more likely to became worse. This is particularly the case for classes that start the school year with a teacher who exerts little influence on what happens in the class and whose 'proximity' in the class is relatively low. In such cases the quality of the relationship gradually decreases even further.
Relationship more likely to deteriorate than improve The research revealed that characteristics such as being strict or friendly were appreciated equally by pupils who experienced the teacher for the first time and pupils who had known the teacher longer. This suggests that the teacher-class relationship is established almost immediately during the initial contact. Therefore the most important implication from this study is that it is probably very difficult for a teacher to fundamentally change a disrupted relationship.
And that is a real cause for dismay because a disrupted relationship does not benefit the learning outcomes of pupils. If the teacher has a good relationship with the pupils then their interest for the subject taught is greater, and if the teacher exerts a large influence on what happens in class, the pupils learn more. Therefore trainee teachers who do not have good contact with a class would probably be better off teaching other classes, rather than trying to improve the relationship in a class where things are not going well. Teaching other classes will increase the chance of trainee teachers learning to enlarge their behavioral repertoire.
Mainhard advises teachers to try to build up a relationship with a class from the outset that is characterized by a large degree of 'influence' and 'proximity'. The study has also revealed that if the relationship is good, a single poor lesson does not mean that the rest of the school year is 'lost'. Instead the relationship often recovers over the course of a week. The researcher does, however, advise against the frequent use of coercion or sanctions in class. Besides causing clear and immediate damage to the relationship with the class, such measures do nothing to increase the teacher's influence in the class.
The PhD research 'Development of teacher-pupil relationship and the interpersonal teacher's competencies' was funded by the Programme Council for Educational Research, part of NWO.
Friday, November 06, 2009
Body bacteria mapped
BBC News on line (November 6, 2009)
Experts map the body's bacteria
University of Colorado Scientists have developed an atlas of the bacteria that live in different regions of the human body. The team found unexpectedly wide variations in bacterial communities from person to person.
They say that it might one day be possible to identify sites on the human body where transplants of specific microbes could benefit health.
The study was based on an intensive analysis of the bacteria found at 27 separate sites on the bodies of nine healthy volunteers. Not only did the bacterial communities vary from person to person, they also varied considerably from one site on the body to another, and from test to test - but some patterns did emerge.
Lead researcher Dr Rob Knight said: "This is the most complete view we have yet of the microbial side of ourselves, one that our group and others will be adding to over the coming years.
"The goal is to find out what is normal for a healthy person, which will provide a baseline for further studies to look at people with diseased states."
There are an estimated 100 trillion microbes living on or inside the human body.
They are thought to play a key role in many physiological functions, including the development of the immune system, digestion of key foods and helping to deter potentially disease-causing pathogens.
The researchers took four samples from each volunteer over a three-month period - usually one to two hours after they had showered.
They used the latest gene sequencing and computer techniques to draw up a profile of the microbes found at each specific site.
Most sites showed big variations in the bacteria they harbored from test to test even within the same individual.
However, there was less variation in the bacteria found in the armpits and soles of the feet - possibly because they provide a dark, moist environment.
The least variation of all was found in the mouth cavity.
Skin sites in the head area, including the forehead, nose, ear and hair, were dominated by one specific type of bacteria.
Sites on the trunk and legs were dominated by a different group.
Researcher Dr Noah Fierer said: "We have an immense number of questions to answer.
"Why do healthy people have such different microbial communities?
"Do we each have distinct microbial signatures at birth, or do they evolve as we age? And how much do they matter?"
reference
Bacterial Community Variation in Human Body Habitats Across Space and Time
Elizabeth K. Costello, Christian L. Lauber, Micah Hamady, Noah Fierer Jeffrey I. Gordon, Rob Knight
Science Published Online November 5, 2009 DOI: 10.1126/science.1177486
Link to Science abstract
Placebo effect
New Scientist (October 24 – 31, 2009)
Placebo effect caught in the act in spinal nerves
The placebo effect's ability to deaden pain has been pinpointed to cells in the spinal cord. This hints at new ways to treat pain.
Falk Eippert of the University Medical Centre Hamburg-Eppendorf in Germany and colleagues scanned the upper spinal cords of 13 volunteers while applying intense heat to the left arm. Then they applied a cream to the arm and told the volunteers it contained a painkiller. In fact it had no active ingredient, but all the same it quenched pain-linked neural activity at lower neck level in the left dorsal horn, which runs the length of the spinal cord
reference
Direct Evidence for Spinal Cord Involvement in Placebo Analgesia
Falk Eippert,
Science, 16 October 2009: Vol. 326. no. 5951, p. 404 DOI: 10.1126/science.1180142
Link to Science abstract
‘Punishing Success’
Keith Alcorn for Aidsmap (November 06, 2009)
International donors must not retreat from commitment to HIV treatment scale-up, MSF warns
A retreat from international funding commitments for AIDS threatens to undermine the dramatic gains made in reducing AIDS-related illness and death in recent years, according to a new report by Médecins Sans Frontières (MSF).
The report highlights a number of signs that donor commitment towards the scale-up of antiretroviral therapy is faltering.
Although many countries have been successful in scaling up treatment services to provides antiretroviral treatment to people in need, few countries have yet achieved the target of `universal access` - diagnosis and treatment of at least 80% of people with HIV with an immediate need for treatment.
According to a recently published report from WHO, UNAIDS and UNICEF, only 42% of people in need of treatment in low and middle-income countries are currently getting it. Nearly five million people are currently in need of treatment.
Loss of momentum in scale-up will lead to continuing high levels of death and illness, and even the erosion of recent gains deaths averted and TB cases prevented, MSF argues.
In the United States funding for PEPFAR will be frozen at current levels for the next two years, indicating that no further expansion of treatment numbers will be possible.
Governments such as those of Malawi and Uganda are now searching desperately for funds to treat the growing number of people with HIV who will require treatment in years to come.
But the report also notes the failure of most African governments to meet a 2001 pledge to devote 15% of resources to health – only eight have reached this target.
reference
Punishing success? Early signs of a retreat from commitment to HIV/AIDS care and treatment
Médecins Sans Frontières 2009
Link to the MSF report
mortality rates high with multiple treatment failures
Kelly Safreed-Harmon for Aidsmap (November 06, 2009)
Multiple treatment failures occur less frequently but remain associated with high mortality rates in North American cohort
Multiple treatment failures declined sharply from 1996 to 2005 in a large cohort of North American adults taking antiretroviral therapy, according to a study published in the November 15th edition of Clinical Infectious Diseases. However, mortality rates remained high among cohort members with multiple treatment failures.
While antiretroviral therapy indisputably slows the progression of HIV disease, its efficacy has been studied primarily in pre-screened clinical trial populations. Less is known about “real-world” treatment outcomes.
Scientists affiliated with the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) sought to understand the clinical impact of treatment failure by analyzing data from more than 36,000 people receiving potent combination antiretroviral regimens at more than 60 sites in Canada and the United States.
“Collectively, these data indicate that the effectiveness of combination antiretroviral therapy continues to improve, even among those patients who experienced failure of an initial regimen,” the paper’s authors conclude. “However, among those who experience virologic failure of at least two distinct regimens, the overall clinical prognosis remains poor.”
The paper observes that the decline in second-line failures probably resulted from a combination of factors, including more effective antiretroviral regimens, earlier initiation of antiretroviral therapy and better medication adherence.
Because the last year of the study period was 2005, findings do not reflect the impact of newer drugs that have provided additional options to people with multiple treatment failures. As the authors note, “one of the most important questions in the field is whether the efficacy of darunavir, raltegravir, maraviroc and etravirine, which was observed in clinical trials, will translate into comparable levels of effectiveness when used more broadly.”
Reference
Trends in multidrug treatment failure and subsequent mortality among antiretroviral therapy-experienced patients with HIV infection in North America.
Steven G. Deeks et al.
Clinical Infectious Diseases 49: 1582–1590, 2009. DOI: 10.1086/644768
Link to CID abstract
‘Prevention and treatment two faces of same coin’
Simeon Bennett for Bloomberg News (November 5, 2009)
AIDS Drugs Should Be Used to Help Prevent Infections, WHO Says
AIDS drugs should be given to all who need them to reduce new infections, the World Health Organization said, taking the view that the same weapons can serve for treatment and prevention.
Providing more antiretroviral drugs “will achieve a significant transmission benefit,” Teguest Guerma, interim director of the WHO’s AIDS department, said in a telephone interview today after a three-day meeting.
“In the past, there has been a false dichotomy between prevention and treatment,” Guerma said. “That is really what has been corrected. Prevention and treatment are two faces of the same coin.”
The meeting comes after a study last year suggested the spread of HIV in hard-hit African nations could be cut by 95 percent in a decade if everyone was tested and those found to be infected were treated immediately. Those projections were questioned last week by another study that said it was based on flawed assumptions. More research is needed, the WHO said.
The so-called “test and treat” strategy may involve millions more people getting treatment in nations already struggling to get drugs to those who need them. At least 5 million people with HIV in poorer nations don’t have access to the medicines out of 9 million who need them, the WHO said in a Sept. 30 report.
The study published last year in The Lancet suggesting a 95 percent cut in transmission was based on unrealistic assumptions that everyone would be tested annually and all those infected would be treated, researchers from the University of California Los Angeles said in the online journal Nature Precedings last week. If 65 percent of those with symptoms and 20 percent of those without were tested, elimination would be possible theoretically in 70 years, the researchers said.
“Even under optimistic assumptions we find elimination to be unlikely,” Sally Blower and Bradley Wagner said in their paper. “Achieving a very high treatment rate would reduce transmission substantially, but not enough to achieve elimination.”
The approach may also cause some people to take greater sexual risks because they see the drugs as a safety net, said Daniel Halperin, a lecturer on global health at Harvard University.
“I worry a little that the whole notion of treatment for prevention, while totally well-meaning, might further enhance this sense of drugs having overcome the epidemic,” Halperin said in an e-mail. “That might make it even more difficult to encourage behavior change and other prevention approaches.”
reference
Voluntary universal testing and treatment is unlikely to lead to HIV elimination: a modeling analysis
Bradley G. Wagner and Sally Blower
Nature Precedings Posted 29 October 2009 hdl:10101/npre.2009.3917.1
Link to Nature Precedings abstract
HIV - bone loss
Michael Carter for Aidsmap (November 05, 2009)
Reassurance for HIV-positive women about short-term risk of bone loss
HIV - lentiviral vector
Jocelyn Kaiser for ScienceNOW Daily News (5 November 2009)
Gene Therapy Halts Brain Disease in Two Boys
Researchers have used a modified AIDS virus to halt a devastating brain disease in two young boys. The treatment, in which the virus delivered a therapeutic gene, marks the first time gene therapy has been successfully used against X-linked adrenoleukodystrophy (ALD)--a disorder that is always fatal if untreated. With this proof of principle, scientists hope versions of the AIDS virus engineered to carry different genes can now be applied to a variety of other diseases.
ALD is caused by a defect in an X chromosome gene that produces a protein called ALD. Cells need this transporter protein to break down certain fats; without it, the fats build up and damage the myelin sheathing that protects nerves. In X-linked ALD, which strikes mainly boys, patients develop neurological symptoms such as seizures and loss of vision around age 6 to 8, and within months they become paralyzed, deaf, and eventually die. In the 1980s, the parents of a boy with ALD developed a mixture of fatty acids they called Lorenzo's oil that may have delayed the disease in their son (and inspired a 1992 movie). But the only widely accepted way to stave off ALD is a bone marrow transplant, which is risky--20% to 30% of patients die or have serious complications--and works best if the donor marrow comes from a sibling.
In search of an alternative, pediatrician Patrick Aubourg of INSERM in Paris, the French biomedical research agency, and the University Paris-Descartes, along with collaborators in France and Germany, tried gene therapy on two 7-year-olds with ALD who couldn't be matched with a bone marrow donor. They removed blood cells from each boy and treated the cells with a so-called lentiviral vector, a modified HIV virus carrying the gene for the enzyme they lacked. The virus could not replicate, but it stitched the gene into the DNA of the blood cells.
To provide the treated cells room to take hold and multiply, the researchers wiped out each patients' bone marrow with chemotherapy. Then they infused the repaired cells back into the patient, and the cells began cranking out ALD protein. The idea was that, after a few months, some of these cells would migrate into the brain.
As expected, parts of the patients' brains that already showed signs of myelin damage initially got worse after the gene therapy, because the modified cells did not migrate into the brain right away. But after 14 to 16 months, the boys' blood cells were still making ALD, and brain images showed that their disease had stabilized or improved, suggesting the protein was being produced there. One boy did worse on a non-verbal IQ test, and the other lost some vision, but their verbal test scores did not drop the way they do in patients who don't get any therapy. The results were comparable to a bone marrow transplant, the researchers report.
"It's a real milestone in the field," says neurologist Florian Eichler of Massachusetts General Hospital in Boston. He cautions, however, that the therapy should not be attempted until a patient shows signs of ALD. That's because many boys with the defective gene do not develop the brain disease, and thus they should not be subjected to such a severe treatment regimen.
The study is also important because it suggests that a lentiviral vector may be safer than some other viruses used for gene therapy, says gene therapy researcher David Williams of Harvard Medical School and Children's Hospital Boston. In the best-known example, another viral vector cured about 20 patients with "bubble boy" immune disease, but it caused leukemia in several of them by inserting its DNA near a cancer gene. An analysis of the ALD patients' blood cells suggested the lentiviral vector is less likely to land in the wrong spot. Williams expects that lentiviral vectors will now be used to treat other genetic diseases that involve blood cells, such as sickle cell disease.
references
Hematopoietic Stem Cell Gene Therapy with a Lentiviral Vector in X-LinkedAdrenoleukodystrophy
Nathalie Cartier et al
Science 6 November 2009 Vol. 326. no. 5954, pp. 818 – 823 DOI: 10.1126/science.1171242
Link to Science abstract
Perspectives: A Comeback for Gene Therapy
Luigi Naldini
Science 6 November 2009: Vol. 326. no. 5954, pp. 805 – 806 DOI: 10.1126/science.1181937
Link to Science summary
Thursday, November 05, 2009
full-fat milk
Science Daily (November 4, 2009)
Children Who Often Drink Full-fat Milk Weigh Less, Swedish Research Finds
Eight-year-old children who drink full-fat milk every day have a lower Body Mass Index than those who seldom drink milk. This is not the case for children who often drink medium-fat or low-fat milk. This is one conclusion of a thesis presented at the Sahlgrenska Academy.
The study showed that children who drink full-fat milk every day weigh on average just over 4 kg less.
"This is an interesting observation, but we don't know why it is so. It may be the case that children who drink full-fat milk tend also to eat other things that affect their weight. Another possible explanation is that children who do not drink full-fat milk drink more soft drinks instead," says dietician Susanne Eriksson, author of the thesis.
The study also discovered a difference between overweight children who drink full-fat milk every day and those who do not. Children who often drink milk with a fat content of 3% are less overweight. The thesis shows also that the children eat more saturated fat than recommended, but those children who have a high intake of fat have a lower BMI than the children with a lower intake of fat.
Susanne Eriksson has investigated the nutrition, body composition and bone mineralization of 120 healthy 8-year-olds. Much of the results can now be used as a standard to determine what is normal for healthy children at that age. The children recounted what they had eaten during the previous day, and answered questions concerning how often they ate certain foods. Various risk markers in the children's blood were also measured.
"Many of these children had been examined when they were four years old, and we discovered that their eating habits were pretty much unchanged four years later. It appears to be the case that eating habits are established early," says Susanne Eriksson.
The thesis found that 62% of the children had low levels of vitamin D in their blood. The general guideline value for all people for vitamin D is 75-100 nmol/l, but most children had less than this. High levels of vitamin D are found in oily fish, while certain dairy products have been fortified with vitamin D. It can be difficult to obtain sufficient levels of the vitamin through the diet.
"We could not determine whether the children's level of vitamin D is correlated with their consumption of fish, but we did see that those children who ate oily fish, such as salmon and mackerel, at least once a week have higher values of the long-chain fatty acids EPA and DHA in their blood. This shows how important it is to eat such fish, instead of processed fish such as fish fingers," says Susanne Eriksson.
reference
Studies on nutrition, body composition and bone mineralization in healthy 8-yr-olds in an urban Swedish community
Susanne Eriksson,
Institute of Clincial Sciences. Department of Pediatrics
University of Gothenburg. Sahlgrenska Academy
Link to Thesis abstract
Circumcision
Michael Carter for Aidsmap (November 05, 2009)
Circumcision protects gay men who have a 'preference' for insertive sex from HIV
Circumcision may protect gay men who are exclusively insertive for anal sex from infection with HIV, an Australian study published in the November 13th edition of AIDS suggests.
But this finding is based upon just seven infections amongst men who expressed a preference for insertive sex. The investigators found that amongst the men who reported only insertive sex as a behavior, circumcision did not significantly reduce the risk of infection with HIV.
The study also showed that overall circumcision did not protect gay men from infection with HIV. Earlier data from the study presented to the conference of the International AIDS Society in Sydney in 2007 showed that circumcision had no protective effect.
Gay and other men who have sex with men continue to be one of the groups most affected by HIV. Consequently, there is a need for new approaches to HIV prevention in this population.
Studies in Africa have shown that circumcision reduces the risk of HIV infection for heterosexual men. However, a recent meta-analysis found no conclusive evidence that circumcision was protective for gay men.
Researchers from the Health in Men (HIM) study therefore investigated the relationship between circumcision and the risk of HIV infection in a population of 1426 HIV-negative gay men in Sydney. In total, 938 of these men were circumcised
It is of note that the investigators so not comment on the possibility of study participants providing inaccurate information about their sexual preferences or behavior. For reasons of social desirability receptive anal sex is consistently under reported by gay men.
Nevertheless, the investigators comment: “Being circumcised was associated with a significant reduction in HIV incidence among the one-third of participants who reported a preference for the insertive role in anal intercourse”.
They do however acknowledge that “the key limitation of our analysis was lack of power due to relatively small numbers of HIV infections in the HIM cohort and the low incidence of HIV infection among predominately insertive men.”
The investigators call for randomized controlled trials to further explore the relationship between circumcision and the risk of HIV for gay men.
Such studies could, however, be difficult to design and the investigators question if they would be worthwhile. They note that the studies “would require high HIV incidence, low baseline circumcision prevalence and large numbers of participants exclusively or predominately practicing the insertive role.” The investigators emphasize that “such attributes are necessary for sufficient study power to detect an association between circumcision status with the relatively infrequent outcome measure of HIV acquisition via insertive anal intercourse.”
Reference
Circumcision and risk of HIV infection in Australian homosexual men
Templeton, David J; Jin, Fengyi; Mao, Limin; Prestage, Garrett P; Donovan, Basil; Imrie, John; Kippax, Susan; Kaldor, John M; Grulich, Andrew E
AIDS. 23(17):2347-2351, November 13, 2009. doi: 10.1097/QAD.0b013e32833202b8
Link to AIDS abstract
Stigma kills (but they say they love you)
Michael Carter for Aidsmap (November 05, 2009)
Certain manifestations of stigma especially hurtful for people with HIV
Legacy from the Maine loss?
365Gay News covers the Associated Press report (November 5, 2009)
Gay Leaders blame TV Ads, Obama for Loss in Maine
Stunned and angry, national gay rights leaders Wednesday blamed scare-mongering ads – and President Barack Obama’s lack of engagement – for a bitter election setback in Maine that could alter the dynamics for both sides in the gay-marriage debate.
Conservatives, in contrast, celebrated Maine voters’ rejection of a law that would have allowed gay couples to wed, depicting it as a warning shot that should deter politicians in other states from pushing for same-sex marriage.
“Every time the citizens have voted on marriage, they have always sided with natural marriage,” said Mathew Staver, founder of Liberty Counsel, a Florida-based Christian legal group. “Maine dramatically illustrates the will of the people, and politicians should wake up and listen.”
Gay activists were frustrated that Obama, who insists he staunchly supports their overall civil rights agenda, didn’t speak out forcefully in defense of Maine’s marriage law before Tuesday’s referendum.
The marriage debate is simmering in at least a half-dozen states where a same-sex marriage bill is pending or where a court ruling or existing law is being eyed by conservatives for possible challenge.
Had Maine’s law been upheld by voters, it would have become the sixth state to legalize gay marriage – and the first to affirm it by popular vote. In Massachusetts, Vermont, Connecticut, New Hampshire and Iowa, gay marriage resulted from court decisions or legislation.
California is sure to be a major battleground over the next several years. Last year, conservatives succeeded in winning public approval of Proposition 8, which overturned a state court ruling allowing gay marriage. Gay rights groups want to take the issue back to the voters but are divided on a timetable.
In the aftermath of the Maine vote, some California activists appealed to their supporters for money to help them put a measure on the 2010 ballot. Other activist leaders want to wait until 2012.
Some California activists said the outcome in Maine strengthened their belief that it will fall to the U.S. Supreme Court – not the voters – to make gay marriage legal. A federal lawsuit challenging Prop. 8 is scheduled to go to trial in January, the first step in a legal journey that is expected to reach the high court in a few years.
“The results in Maine underscore exactly why we are challenging California’s same-sex marriage ban,” said Chad Griffin, president of the American Foundation for Equal Rights, the Los Angeles group spearheading the lawsuit. “The U.S. Constitution guarantees equal rights to every American, and when those rights are violated, it is the role of our courts to protect us, regardless of what the polls say.”
In Washington, D.C., conservatives are trying to force a popular vote on a bill headed toward City Council approval that would legalize gay marriage. Michael Crawford, one of the leaders of the local pro-gay marriage campaign, said the result in Maine increased his determination to avoid a ballot measure.
“The same cabal of anti-gay groups who stripped away marriage equality from our families in California and Maine now have their sights on D.C.,” he said.
Crawford was among numerous gay rights leaders complaining about the campaign tactics of the groups that opposed same-sex marriage in Maine and California.
In both states, California-based political strategist Frank Schubert oversaw an advertising campaign warning that “homosexual marriage” would be taught in public schools.
The campaign to defend gay marriage countered that Maine’s state curriculum guidelines contain no reference to marriage, and the state’s Democratic attorney general, Janet Mills, issued an opinion backing that up. But the ads continued.
“It is infuriating to see that the same fear-mongering ads that were used to pass Prop. 8 a year ago have triumphed again at the expense of so many,” said Joe Solmonese of the Human Rights Campaign, the largest national gay rights group.
Health – spending more but . . .
Yahoo News covers the Julie Steenhuysen Reuters report (November 5, 2009)
U.S. spends most, but health quality lags
Americans are more likely than people in 10 other countries to have trouble getting medical treatment because of insurance restrictions or cost, an international survey of primary care doctors released on Wednesday found.
While the United States spends more than twice as much as other developed countries on healthcare, it lags well behind in key measures of quality, the annual survey found.
"Our weak primary care system puts patients at risk and results in poor health outcomes and higher costs," said Karen Davis, president of the Commonwealth Fund, a private health policy group that sponsored the survey.
Other countries have solved problems the United States is still struggling to conquer, she said.
The survey of more than 10,000 primary care doctors in 11 developed countries -- Australia, Canada, France, Germany, Italy, the Netherlands, New Zealand, Norway, Sweden and the United Kingdom -- found problems in all of them.
In the United States, cost and access to care stood out as a major challenge for primary care doctors.
"The majority of U.S. doctors -- some 58 percent -- say their patients often have difficulty paying for medications and other medical care, by far the highest rate in the survey," Cathy Schoen of the Commonwealth Fund, whose study appears in the journal Health Affairs, told the briefing.
Paying for healthcare was a problem in 5 to 37 percent of other countries surveyed.
Insurance restrictions, such as provisions to limit or control medication or treatment, are a major impediment for U.S. doctors, with half of 1,400 physicians surveyed saying the time they and their staff spend dealing with insurance companies is a major problem.
The survey from February to July 2009 was conducted by mail, online and by phone.
"It appears that U.S. doctors are adding staff to their offices that would not be typical of other countries just to cope with our complex, fragmented insurance system and advocate for their patients," Schoen said.
The survey also asked doctors if patients in their country could see a doctor after regular business hours without being forced to go to the emergency room.
Nearly all doctors surveyed from the Netherlands, New Zealand and the United Kingdom said this was offered, compared with just 29 percent of doctors in the United States -- which ranked lowest in the survey.
"The vast majority say they have no arrangement at all," Schoen said, adding that the 29 percent figure is a drop from 40 percent reported in 2006.
The study also shows the United States and Canada trail other developed countries in the use of basic electronic medical records. Less than half of U.S. doctors (46 percent) say they have electronic medical records, and just 37 percent of doctors in Canada have them.
Electronic medical records are nearly universal in the Netherlands, New Zealand, the United Kingdom, Australia, Italy, Norway and Sweden.
"The findings underscore the extent to which national policies matter," Schoen said.
reference
A Survey Of Primary Care Physicians In Eleven Countries, 2009: Perspectives On Care, Costs, And Experiences
Cathy Schoen, Robin Osborn, Michelle M. Doty, David Squires, Jordon Peugh and Sandra Applebaum
Health Affairs, 28, no. 6 (2009): w1171-w1183 (Published online 2 November 2009) doi: 10.1377/hlthaff.28.6.w1171
by Project HOPE
Link to Health Affairs abstract
Wednesday, November 04, 2009
disappearing honeybees?
Marcelo Aizen and Lawrence Harder for New Scientist (October 24 – 31, 2009)
The truth about the disappearing honeybees
Heard what Einstein said about humans having four years to live if the bees died out?
Well he didn’t and we won’t. Marcelo Aizen and Lawrence Harder explain in their article
‘masculinity is the norm’
Science Daily (November 4, 2009)
Preschoolers Challenge Stereotypical Gender Roles
According to research from the University of Gothenburg, a preschooler's gender determines how he or she is treated and responded to in play and learning activities, and when the children's possibilities become expanded, it is usually a result of the children's and not the teachers' initiative.
The Swedish preschool curriculum requires promotion of gender equality, but researchers at the University of Gothenburg's Department of Education, who performed gender analysis of 114 video sequences of six preschool groups (in total 45 hours of material), conclude that this may be easier said than done.
The analysis shows that girls' questions and comments are responded to differently (in a negative sense), that teachers tend to masculinize teaching tools and that masculinity is the norm in children's play and art work. These tendencies are reinforced in the interaction between teachers and children since teachers often have stereotypical ideas of what boys and girls are interested in. Yet, the analysis also identified that boys and girls very often share play and learning with each other. Furthermore, they show great concern for each other by being helpful and taking responsibility for others' well-being regardless of gender.
The analysis also shows how children manage to achieve border crossing at preschool, which causes stereotypical gender structures to change. An example of border crossing is when a LEGO figure that has been gender-defined by a teacher is redefined by a child from 'man' to 'mum'.
As Professor Ingrid Pramling Samuelsson and doctoral student Eva Ärlemalm-Hagsér write in the current issue of Pedagogisk Forskning i Sverige: "Both children and teachers contribute to the creation and expression of gender structures at preschool."
"But the study finds that it is the children that reformulate and expand their possibilities. There is not a single example in the material where teachers consciously challenge children to engage in border crossing."
Coffee?
Université de Montréal News (November 2, 2009)
Java And Nighttime Jobs Don't Mix: Study
Night-shift workers should avoid drinking coffee if they wish to improve their sleep, according to research published in the journal Sleep Medicine. A new study led by Julie Carrier, a Université de Montréal psychology professor and a researcher at the affiliated Hôpital du Sacré-Cœur Sleep Disorders Centre, has found the main byproduct of coffee, caffeine, interferes with sleep and this side-effect worsens as people age.
"Caffeine is the most widely used stimulant to counteract sleepiness, yet it has detrimental effects on the sleep of night-shift workers who must slumber during the day, just as their biological clock sends a strong wake-up signal," says Carrier. "The older you get, the more affected your sleep will be by coffee."
Twenty-four men and women participated in the study: one group was aged 20 to 30, while a second group was aged 45 to 60. Everyone spent two sleepless nights in lab rooms before being allowed to sleep. "We all know someone who claims to sleep like a baby after drinking an espresso. Although they may not notice it, their sleep will not be as deep and will likely be more perturbed," says Professor Carrier.
Both participant groups had to take a pill three hours before sleeping; either 200 milligrams of caffeine or a lactose-based placebo. All subjects who consumed caffeine pills had their sleep affected, especially older participants who slept 50 percent less than usual. In both age groups, caffeine decreased sleep efficiency, sleep duration, slow-wave sleep (SWS) and REM sleep.
The combined influence of age and caffeine made the sleep of middle-aged subjects particularly vulnerable to the circadian waking signal. Professor Carrier suggests that lower brain synchronization -- caused by age and caffeine -- produces greater difficulty in overriding circadian waking signals during daytime and that leads to fragmented sleep. These results have implications for the high proportion of the population using caffeine to cope with night work and jetlag, particularly the middle-aged.
Carrier recommends that everyone over 40 reduce their coffee consumption, especially if they work at night. Her study builds on recent findings that reducing coffee consumption is the best way to improve sleep for the middle-aged.
reference:
Effects of caffeine on daytime recovery sleep: A double challenge to the sleep–wake cycle in aging.
Julie Carrier, Jean Paquet, Marta Fernandez-Bolanos, Laurence Girouard, Joanie Roy, Brahim Selmaoui and Daniel Filipini
Sleep Medicine, 2009; 10 (9): 1016 DOI: 10.1016/j.sleep.2009.01.001
Link to Sleep Med abstract
antibiotic-resistant bacteria
Science Daily (November 1, 2009)
Bacteria 'Launch A Shield' To Resist Attack
— Researchers from the University of Copenhagen and the Technical University of Denmark along with other collaborators in Denmark and the US found that the bacterium Pseudomonas aeruginosa can 'switch on' production of molecules that kill white blood cells -- preventing the bacteria being eliminated by the body's immune system.
P. aeruginosa is responsible for many hospital-acquired infections and also causes chronic infections in those with pre-existing medical conditions such as cystic fibrosis (CF). The bacteria cause persistent lung infections by clumping together to form a biofilm, which spreads over the lungs like a slime. Such biofilms are generally resistant to antibiotics as well as the host immune response.
The study showed that P. aeruginosa uses a well-studied communication system called quorum sensing (QS) to detect approaching white blood cells and warn other bacteria in the biofilm. In response to this signal, the bacteria increase their production of molecules called rhamnolipids. These molecules sit on the biofilm surface to form a shield that destroys any white blood cells that encounter it. Interrupting quorum sensing to halt the "launch a shield" response could be a way of treating these bacteria that can resist antibiotics as well as the host immune system.
Professor Michael Givskov from the University of Copenhagen who led the study believes there are significant clinical benefits to this research. "The ultimate goal [of this research] is to eradicate the present day's antibiotic-resistant bacteria that are involved in the bulk of chronic infections," he says. "Antibiotic resistance is one of the most serious emerging health problems in the world today. More than 70% of the disease-causing bacteria are resistant to at least one of the currently available antibiotics. Studying interactions between P. aeruginosa and the innate and adaptive immune response will provide valuable information for the design of novel antimicrobials."
$20 billion to die
Yahoo News covers the Reuters report (November 4, 2009)
A third of Americans die in hospitals, study finds
Nearly a third of Americans who die are in the hospital at the time and their last treatments cost the U.S. economy $20 billion, according to a report released on Wednesday.
The single biggest cause of hospital death was septicemia, an overwhelming infection of the blood, which killed 15 percent of patients, the team at the U.S. Agency for Healthcare Research and Quality found.
Eight percent died of respiratory failure, 6 percent died of stroke and 5 percent had fatal heart attacks in the hospital, according to the report.
"In 2007, it is estimated by the Centers for Disease Control that 2,423,995 people died in the United States. Of these, we estimate that 765,651 died in the hospital," the agency's Yafu Zhao and William Encinosa wrote.
"That is, 32 percent of all deaths in the U.S. in 2007 occurred in the hospital."
Their analysis, using federal survey data, found that the average cost of a hospital stay that ended with the patient's death was $26,035, compared to $9,447 for patients discharged alive.
Patients covered by Medicare, the federal health insurance plan for the elderly and disabled, accounted for 67 percent of in-hospital deaths and $12 billion in hospital costs.
Private insurance covered 20 percent of patients who died at a cost of $4 billion. Medicaid patients made up 2 percent and uninsured patients accounted for 3 percent and $630 million in costs.
reference
The Costs of End-of-Life Hospitalizations, 2007
Yafu Zhao, M.S. and William Encinosa, Ph.D.
Healthcare Cost And Utilization Project: Statistical Brief #82 (November 2009)
Agency for Healthcare Research and Quality
Link to AHRQ report [pdf]
MRSA
Science Daily (November 3, 2009)
MRSA Strain Linked To High Death Rates
A strain of MRSA that causes bloodstream infections is five times more lethal than other strains and has shown to have some resistance to the potent antibiotic drug vancomycin used to treat MRSA, according to a Henry Ford Hospital study.
The study found that 50 percent of the patients infected with the strain died within 30 days compared to 11 percent of patients infected with other MRSA strains.
The average 30-day mortality rate for MRSA bloodstream infections ranges from 10 percent to 30 percent.
Researchers say the strain USA600 contains unique characteristics that may be linked to the high mortality rate. But they say it is unclear whether other factors like the patients' older age, diseases or the spread of infection contributed to the poor outcomes collectively or with other factors. The average age of patients with the USA600 strain was 64; the average age of patients with other MRSA strains was 52.
The study was presented at the 47th annual meeting of the Infectious Diseases Society of America Oct. 29-Nov. 1 in Philadelphia.
"While many MRSA strains are associated with poor outcomes, the USA600 strain has shown to be more lethal and cause high mortality rates," says Carol Moore, PharmD., a research investigator in Henry Ford's Division of Infectious Diseases and lead author of the study.
"In light of the potential for the spread of this virulent and resistant strain and its associated mortality, it is essential that more effort be directed to better understanding this strain to develop measures for managing it."
Tuesday, November 03, 2009
Swine flu --- all ages
Yahoo News covers the Julie Steenhuysen Reuters report (November 3, 2009)
Swine flu not just a threat to young: study
Swine flu can cause severe disease in people of all ages and appears to pose a special threat to those who are obese, according to an analysis of H1N1 cases in California.
Public health researchers analyzed the state's first 1,088 hospitalized and fatal cases of H1N1 infection between April 23 and August 1.
Like other studies, they found the average patient who was hospitalized with H1N1 flu was younger than what is commonly seen with seasonal flu, but they also found severe disease at both ends of the age spectrum.
"What our study shows was that once you were hospitalized, if you were elderly you have a higher risk of dying," Dr. Janice Louie of the California Department of Public Health in Richmond, whose study appears in the Journal of the American Medical Association.
Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, said the study matches the CDC's own observations -- that H1N1 affects all age groups, including people over 65.
"If they get it, it can be every bit as severe as seasonal flu, consistent with other data," Frieden told a news briefing.
"It does emphasize that providers should think of H1N1 influenza in all age groups," he said.
Frieden said the new findings do not change the CDC's recommendations for vaccination, which focus on younger people, those with underlying conditions such as asthma and pregnant women.
What it does suggest is that doctors need to be aware of the risks to their older patients if they do become infected, Louie said.
"One of the perceptions we've been trying to dispel is that this is a mild disease," she said in a telephone interview.
"This can be very severe. In this paper, 30 percent of patients required intensive care."
Overall, 11 percent of people who were hospitalized died, but among people 50 and older, 18 to 20 percent died.
The most common causes of death were viral pneumonia and acute respiratory distress syndrome.
As with other studies, obesity appeared to play a significant role in the severity of disease.
reference
Factors Associated With Death or Hospitalization Due to Pandemic 2009 Influenza A(H1N1) Infection in California
Janice K. Louie, MD, MPH et al
JAMA. 2009;302(17):1896-1902.
Link to JAMA abstract
bully
New Scientist (October 24 – 31, 2009)
Your bullying boss really is an idiot
Research shows that leaders who feel incompetent really do lash out to temper their own inferiority.
When bosses feel they can't legitimately show superiority and competence, they take people down a notch or two, says Nathanael Fast of the University of Southern California in Los Angeles.
To see if a bruised ego can cause aggression, Fast and his colleague Serena Chen manipulated people's sense of power and self-worth by asking them to write about occasions when they felt either empowered or impotent and then either competent or incompetent.
Next, the volunteers selected a punishment suitable for students who gave wrong answers in a test, with a choice of horn sounds ranging from 10 decibels to a deafening 130 decibels.
The volunteers who felt the most incompetent but most empowered picked the loudest punishments - 71 decibels on average. Workers who felt up to their jobs selected quieter punishments, between 55 and 62 decibels, as did those primed to feel incompetent yet powerless
Flattery helped. When Fast and Chen praised the leadership skills of their volunteers, the aggressive tendencies all but disappeared.
reference
When the Boss Feels Inadequate: Power, Incompetence, and Aggression
Nathanael J. Fast and Serena Chen
Psychological Science, published in advance on line October 8, 2009 DOI: 10.1111/j.1467-9280.2009.02452.x
Link to Psychological Science abstract
Abuse hurts
Joyann Callender for University of Toronto News (November 2, 2009)
Study finds link between childhood physical abuse and arthritis
— Adults who had experienced physical abuse as children have 56 per cent higher odds of osteoarthritis compared to those who have not been abused, according to a new study by University of Toronto researchers.
University of Toronto researchers investigated the relationship between self-reported childhood physical abuse and a diagnosis of osteoarthritis (OA). After analyzing representative data from the 2005 Canadian Community Health Survey, the researchers determined a significant association between childhood physical abuse and osteoarthritis in adulthood.
Osteoarthritis is an often debilitating chronic condition that affects millions of adults. "We found that 10.2 per cent of those with osteoarthritis reported they had been physically abused as children in comparison to 6.5 per cent of those without osteoarthritis," says lead author Esme Fuller-Thomson of U of T's Factor-Inwentash Faculty of Social Work and Department of Family and Community Medicine. "This study provides further support for the need to investigate the possible role that childhood abuse plays in the development of chronic illness."
Co-author Sarah Brennenstuhl, a doctoral student at the University of Toronto, stated that, "We were surprised that the significant association between childhood physical abuse and osteoarthritis persisted even after controlling for major potentially confounding factors such as obesity, physical activity levels as well as age, gender, income and race." According to Fuller-Thomson, one important avenue for future research is to investigate the pathways through which arthritis may develop as a consequence of childhood physical abuse.
reference
The robust association between childhood physical abuse and osteoarthritis in adulthood: Findings from a representative community sample (p 1554-1562)
Esme Fuller-Thomson, Maria Stefanyk, Sarah Brennenstuhl
Arthritis Care & Research Volume 61 Issue 11, Pages 1554 – 1562 Published Online: Oct 29 2009 DOI: 10.1002/art.24871
Link to Arthritis Care & Research abstract
Extinction
BBC News on line (November 3, 2009)
Species' extinction threat grows
Out of the 47,677 species in the IUCN Red List of Threatened Species, 17,291 are deemed to be at serious risk. More than a third of species assessed in the major international biodiversity study are threatened with extinction.
These included 21% of mammals, 30% of amphibians, 70% of plants and 35% of invertebrates.
"The scientific evidence of a serious extinction crisis is mounting," warned Jane Smart, director of the International Union for the Conservation of Nature's (IUCN) Biodiversity Conservation Group.
"The latest analysis... shows that the 2010 target to reduce biodiversity loss will not be met," she added.
"It's time for governments to start getting serious about saving species and make sure it's high on their agendas for next year, as we are rapidly running out of time."
The Red List, regarded as the most authoritative assessment of the state of the planet's species, draws on the work of thousands of scientists around the globe.
The latest update lists amphibians as the most seriously affected group of organisms on the planet, with 1,895 of the 6,285 known species listed as threatened.
Of these, it lists 39 species as either "extinct" or "extinct in the wild". A further 484 are deemed "critically endangered", 754 "endangered" and 657 "vulnerable".
The Kihansi Spray Toad ( Nectophyrnoides asperginis ) is one species that has seen its status change from critically endangered to extinct in the wild.
It was only found in the Kihamsi Falls area of Tanzania, but its population had crashed in recent years from a high of an estimated 17,000 individuals.
Conservationists suggest that the rapid decline was primarily the result of a dam being constructed upstream from the toads' habitat, which resulted in a 90% reduction in the flow of water.
"In our lifetime, we have gone from having to worry about a relatively small number of highly threatened species to the collapse of entire ecosystems," observed Professor Jonathan Baillie, director of conservation programs at the Zoological Society of London (ZSL).
"At what point will society truly respond to this growing crisis?"
ViiV Healthcare
Roger Pebody for Aidsmap (November 03, 2009)
GSK and Pfizer launch joint venture, ViiV Healthcare
The pharmaceutical companies GlaxoSmithKline and Pfizer announced today that the joint venture created by the merger of their HIV divisions is called ViiV Healthcare. The deal was first announced in April, and aims to improve the two companies’ position in the HIV market by cutting costs, sharing research and combining sales operations.
The new company has a 19% share of the global drugs market, in comparison to Gilead’s 31%.
GlaxoSmithKline (GSK) will initially control 85 per cent and Pfizer the remaining 15 per cent of the shares, with the proportions rising or falling depending on the relative success of the two companies’ drugs.
The company has a portfolio of ten licensed anti-HIV products, plus seven investigational drugs in phase I and phase II clinical trials. The licensed drugs include GSK’s combination pills Combivir (AZT and 3TC) and Kivexa (abacavir and 3TC). Pfizer’s sole licensed anti-HIV drug is the CCR5 inhibitor, maraviroc (Celsentri).
The company says that their research will not solely focus on creating new molecules, but will try to develop new formulations that are easier to adhere to, including paediatric fixed-dose combinations.
Dominique Limet, the new chief executive, told Reuters that “Our intent is to look at what we can do with the portfolio we get from Pfizer and Glaxo to build new combinations which will completely transform the way we treat HIV.”
The company also states that it is committed to broadening access to medicines around the world and maintaining GSK’s Positive Action program, which supports community projects.
“Much of our historic effort has been led by the virus – a chase of science,” Limet commented. “This must continue, but we must also listen and better understand the needs of people living with HIV.”
‘Epidemic Will Remain Out of Control’
Donald G. McNeil Jr.’s Global Update for The New York Times (November 3, 2009)
Unless there is a drastic change in approach, the AIDS epidemic will still be out of control on its 50th anniversary in 2031, a panel of AIDS experts predicted in an analysis being published in the journal Health Affairs.
The lead author, Robert Hecht, an economist and former policymaker at the United Nations and the International AIDS Vaccine Initiative, predicted that by that time, poor countries would need $35 billion a year — three times what is spent now — to treat AIDS patients, care for orphans and do prevention work.
Rapidly developing countries like Brazil, China, India, Mexico and Russia should be able to pay for fighting their own relatively small epidemics, the authors said. Southern African countries will need only some help, despite having the world’s highest AIDS rates. But much of Africa, and especially Kenya, Mozambique, Uganda and Zambia, will remain heavily dependent on donors.
reference
Critical Choices In Financing The Response To The Global HIV/AIDS Pandemic
Robert Hecht,
Health Affairs, 28, no. 6 (2009): 1591-1605 doi: 10.1377/hlthaff.28.6.1591
Link to Health Affairs abstract
Monday, November 02, 2009
You are what you eat?
BBC News on line (November 2, 2009)
Depression link to processed food
Eating a diet high in processed food increases the risk of depression and people who ate plenty of vegetables, fruit and fish actually had a lower risk of depression, a University College London team found.
Data on diet among 3,500 middle-aged civil servants was compared with depression five years later. The researcher split the participants into two types of diet - those who ate a diet largely based on whole foods, which includes lots of fruit, vegetables and fish, and those who ate a mainly processed food diet, such as sweetened desserts, fried food, processed meat, refined grains and high-fat dairy products.
After accounting for factors such as gender, age, education, physical activity, smoking habits and chronic diseases, they found a significant difference in future depression risk with the different diets.
Those who ate the most whole foods had a 26% lower risk of future depression than those who at the least whole foods.
By contrast people with a diet high in processed food had a 58% higher risk of depression than those who ate very few processed foods.
Although the researchers cannot totally rule out the possibility that people with depression may eat a less healthy diet they believe it is unlikely to be the reason for the findings because there was no association with diet and previous diagnosis of depression.
Study author Dr Archana Singh-Manoux pointed out there is a chance the finding could be explained by a lifestyle factor they had not accounted for.
"There was a paper showing a Mediterranean diet was associated with a lower risk of depression but the problem with that is if you live in Britain the likelihood of you eating a Mediterranean diet is not very high.
"So we wanted to look at bit differently at the link between diet and mental health."
It is not yet clear why some foods may protect against or increase the risk of depression but scientists think there may be a link with inflammation as with conditions such as heart disease.
reference
Dietary pattern and depressive symptoms in middle age
Tasnime N. Akbaraly, Eric J. Brunner, Jane E. Ferrie, Michael G. Marmot, Mika Kivimaki, and Archana Singh-Manoux
The British Journal of Psychiatry, Nov 2009; 195: 408 - 413. doi: 10.1192/bjp.bp.108.058925
Link to BJP abstract
high malaria drug prices
Yahoo News covers the Kate Kelland Reuters report (November 2, 2009)
Millions die because of high malaria drug prices
Nearly a million people die from malaria each year because they cannot afford the most effective treatment and instead often buy old drugs to which the malaria parasite has become resistant, researchers said on Monday.
Artemisinin combination therapy, or ACT, drugs made by firms such as Novartis and Sanofi-Aventis can cost as much as 65 times the daily minimum wage in some African countries, according to a study of 6 high-risk nations by Populations Services International Malaria.
ACTs can cost up to $11 to patients buying over the counter, while older drugs to less effective drugs cost just $0.30 cents.
"With most people accessing anti-malarial medication through the private sector, price becomes a critically important barrier," said Desmond Chavasse, director of PSI.
"A full course of an adult treatment of ACT can be up to 65 times the minimum daily wage. This provides an overpowering incentive (for patients) to make the wrong anti-malarial choice."
Chavasse was speaking to reporters from Nairobi, where he was at an international malaria conference to present a study called ACTwatch -- a research project by PSI and the London School of Hygiene and Tropical Medicine on the malaria drugs market across 6 sub-Saharan African countries and Cambodia.
Link to ACTwatch results
Fifth MIM Pan-African Malaria Conference (PAMC) Nairobi, Kenya, November 2 - 6, 2009
Link to Conference virtual press room
‘influenza virus evolves’
Science Daily (November 2, 2009)
New Model May Help Scientists Better Predict And Prevent Influenza Outbreaks
— Each year, the influenza virus evolves. And each year, public health officials try to predict what the new strain will be and how it will affect the population in order to best combat it.
A new study by an international team of researchers, led by assistant professor Andrew W. Park, who holds a joint appointment in the University of Georgia Odum School of Ecology and in the College of Veterinary Medicine, may make their task a little easier. The study breaks ground by working across scales and linking sub-molecular changes in the influenza virus to the likelihood of influenza outbreaks. The paper, published in the Oct. 30 edition of the journal Science, shows the relationship between the evolution of the virus and immunization rates needed to prevent an outbreak in the population.
Park explained that these findings can help inform efforts to prevent future outbreaks. "Public health officials will be able to assess the usefulness of a vaccine based upon its relationship to the current influenza strain and the population's immunity level," he said.
Through previous vaccinations or infections with earlier strains of the influenza virus, many individuals already have some level of immunity, Park noted. The influenza virus is continually evolving, however. By substituting different amino acids at key molecular points, the virus increases its chances of evading the immune system's defenses, allowing it to reproduce and spread.
As the number of amino acid differences between a new strain and the strain an individual was vaccinated against increases, the likelihood of becoming infected increases, Park said, as does the likelihood of becoming infectious and the length of time the individual will remain infectious. These factors combine to increase the chance of an outbreak in a population.
Working with equine influenza, the research team members looked at the likelihood of an influenza outbreak in a population that had all been vaccinated with the same strain of the virus. They found that outbreaks began occurring when there were two or more amino acid differences and that the size of the outbreak increased with the number of amino acid differences. They also found that large outbreaks were more likely to occur if the virus and the vaccine were from different antigenic clusters -- meaning that a host's immune system perceives the two strains as different. Comparing these results with an earlier human influenza study revealed similar trends.
Another key factor in determining the risk of an outbreak in real populations, however, is the individual variation of immunity in the population. Because the virus keeps changing, so do the vaccines used against it. This causes the immunity of the population to be heterogeneous -- some individuals have been infected with or vaccinated against last year's influenza strain, some against strains from previous years, and some have no immunity at all. Park and his colleagues found that the degree of variability of immunity in the population plays a crucial role in determining the risk of an outbreak.
Park added that in measuring for the first time how the difference between the population's immunity status and a new virus strain influences the risk of an epidemic, the team has taken a critical step toward linking these relationships with the dynamics of epidemics, not just for influenza but for a wide range of infectious diseases.
reference
Quantifying the Impact of Immune Escape on Transmission Dynamics of Influenza
Andrew W. Park, Janet M. Daly, Nicola S. Lewis, Derek J. Smith, James L. N. Wood, and Bryan T. Grenfell
Science 30 October 2009 326: 726-728 DOI: 10.1126/science.1175980
Link to Science abstract
Sunday, November 01, 2009
facial attraction
Amy Lavoie for Harvard Gazette (October 29, 2009)
Facing your preferences
For gay and straight men, gauging facial attraction appears to operate similarly
A new study from a researcher at Harvard University finds that gay men are most attracted to the most masculine-faced men, while straight men prefer the most feminine-faced women.
The findings suggest that regardless of sexual orientation, men's brains are wired for attraction to sexually dimorphic faces -- those with facial features that are most synonymous with their gender.
The research is currently published online in the journal Archives of Sexual Behavior, and was led by Aaron Glassenberg, while completing his master's degree in the Department of Psychology at Harvard. Glassenberg is currently a Ph.D. student in organizational behavior in Harvard's Faculty of Arts and Sciences and Harvard Business School. His co-authors are David Feinberg of McMaster University, Benedict Jones and Lisa DeBruine of Aberdeen University, and Anthony Little of Stirling University.
"Our work showed that gay men found highly masculine male faces to be significantly more attractive than feminine male faces. Also, the types of male faces that gay men found attractive generally did not mirror the types of faces that straight women found attractive on average," says Glassenberg. "Men, gay or straight, prefer high sexual dimorphism in the faces of the sex that they are attracted to. Gay men and straight men did not agree on the types of male faces they considered attractive."
The study is the first to examine the facial feature preferences of gay men and lesbian women. Women's preferences are more complex than men's, as indicated by prior research demonstrating that ovulation, contraceptive use, self-perceived attractiveness, and sex drive all affect face preference. In this particular study, straight women preferred more masculine-faced men than lesbian women, while lesbians preferred slightly more masculine female faces than straight women or men.
Participants viewed images of faces that were digitally manipulated to be more masculine or feminine, and then indicated which face they considered more attractive. The study was conducted online, and included over 900 men and women.
Sexually dimorphic features in male faces include a broad jaw, broad forehead, and more pronounced brow ridge. A sexually dimorphic female face has a more tapered chin, larger lips, and a narrower forehead.
Prior research has also shown that women prefer more masculine male faces when ovulating, indicating an evolutionary function for facial attraction. Men who have faces that are higher in sexual dimorphism (masculinity) have been shown to have better health and dominance but lower investment in offspring.
Although it is difficult to make substantial evolutionary claims from this study, Glassenberg's work supports the idea that male attraction operates differently from female attraction, regardless of sexual orientation.
reference
Sex-Dimorphic Face Shape Preference in Heterosexual and Homosexual Men and Women
Aaron N. Glassenberg, David R. Feinberg, Benedict C. Jones, Anthony C. Little and Lisa M. DeBruine
Archives of Sexual Behavior Published online: 15 October 2009 doi 10.1007/s10508-009-9559-6
Link to ASB abstract
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