“Many fathers of sexually abused children want revenge and express the desire to torture their child’s aggressor,” says Allard, a PhD student at the Université de Montréal Department of Psychology. “Supporting the mother is essential to the recovery of the child. And the focus is often put on the mother because the father is the aggressor. But what happens in cases where the father is not the aggressor?”

Preliminary data provides some insight on the extent of the trauma experienced by fathers. “Their situation is particularly difficult,” says Allard. “The most violent reactions arise when the aggressor is the stepfather of the child, the mother’s new boyfriend or her new husband.”

Cases in which vengeance is not the dominant emotion are ones where the aggressor is a family member with whom the father has an emotional bond. This was the situation in more than 50 percent of cases.

For many fathers, the dominant emotion is grief. “Some fathers draw comparisons with the death of a loved one, as many grieve the death of their child’s innocence,” says Allard. “Fathers told us they became reluctant to tickle their child or give them a bath fearing that physical contact would remind the child of the aggression.”

In some cases, a child can reject their father because their aggressor was a man, too. These fathers struggle with deep feelings of helplessness and dismissal. On the other hand, an aggression can become an opportunity for advancing a father-child relationship, especially when the father realizes how sustaining such a relationship is in the best interest of their child.

Allard’s study is currently underway and supervised by Mireille Cyr, a professor at the Université de Montréal Department of Psychology as well as Milène Fernet of the Université du Québec à Montréal. Her research requires the continued contribution of fathers whose child has experienced sexual abuse.

Source:
Sylvain-Jacques Desjardins
University of Montreal

A paper on the discovery, by investigators from Columbia, Rockefeller and Stanford Universities in the US, and research centers in Italy and Switzerland, was published online in the 15 April issue of Nature.

The progressive hair loss of hereditary hypotrichosis simplex begins in childhood through a process called hair follicle miniaturization, which also occurs in male pattern baldness or androgenetic alopecia. The process causes hair follicles to shrink so the hair they produce gradually becomes thinner and thinner, until a thick head of hair eventually becomes what is known as “peach fuzz”.

In this study, the researchers found that the gene APCDD1 causes hereditary hypotrichosis simplex and thus gives some insights into hair follicle miniaturization. But, they pointed out that this does not mean the same gene causes male pattern baldness, even though it also involves hair follicle miniaturization.

Lead author Dr Angela M. Christiano, professor of dermatology and genetics and development at Columbia University Medical Center, said in a statement:

“It is important to note that while these two conditions share the same physiologic process, the gene we discovered for hereditary hypotrichosis does not explain the complex process of male pattern baldness.”

For the study, Christiano and colleagues analyzed genetic data from families from Pakistan and Italy with hereditary hypotrichosis simplex and found they shared a particular mutation of APCDD1.

The gene occurs in a region of chromosome 18 that has already been linked to other forms of hair loss, including male pattern baldness or androgenetic alopecia and alopecia areata.

The researchers also found the gene blocks a signalling pathway called Wnt, which has been known for some time to control hair growth in mice, but until this study it was not clear if it had the same effect in humans.

They concluded that as APCDD1 is expressed in a broad repertoire of cell types, their discovery may imply that the gene is also involved in diverse other biological processes regulated by Wnt signalling.

Christiano said the discovery was highly significant because it is the first evidence that Wnt is is critical in human hair growth.

“Furthermore, these findings suggest that manipulating the Wnt pathway may have an effect on hair follicle growth – for the first time, in humans,” she added, explaining that unlike current treatments for hair loss that block hormone pathways:

“… treatments involving the Wnt pathway would be non-hormonal, which may enable many more people suffering from hair loss to receive such therapies,” said Christiano.

“APCDD1 is a novel Wnt inhibitor mutated in hereditary hypotrichosis simplex.”
Yutaka Shimomura, Dritan Agalliu, Alin Vonica, Victor Luria, Muhammad Wajid, Alessandra Baumer, Serena Belli, Lynn Petukhova, Albert Schinzel, Ali H. Brivanlou, Ben A. Barres and Angela M. Christiano.
Nature 464, 1043-1047, Published online 15 April 2010
DOI:10.1038/nature08875

Source: Columbia University Medical Center.

Written by: Catharine Paddock, PhD

During sexual intercourse, HIV-infected men transmit HIV through their semen, which carries free-floating virus as well as HIV-infected leukocytes. Traces of HIV have been detected on sperm as well, but the role they play in viral transmission has been a matter of debate. After all, men with vasectomies can transmit HIV. Now, Ceballos et al. show that HIV attaches to the surface of sperm and that these HIV carriers pass on the virus to DCs and other HIV targets.

Sperm express molecules known to interact with HIV’s envelope, such as heparan sulfate and mannose receptors. The authors show that HIV relies on heparan sulfate to attach to sperm, but not mannose receptors as previously predicted.

Once attached, the virus was transmitted from sperm to DCs in culture. The DC receptors CD4 and DC-SIGN were required for transmission, suggesting that DCs pick up the virus by binding to sperm rather than by ingesting them. DCs matured after interacting with the sperm, producing tolerance-promoting cytokines like interleukin-10. The authors speculate that this immune-suppressing profile, versus an inflammatory profile, might also help the virus spread.

Sperm might reach DCs by passing through microabrasions in the vaginal or anal lining that often form during intercourse, suggest the authors. Or they might contact the finger-like projections of DCs that extend to the surface of mucosal linings. Furthermore, the team found that a slightly acidic pH, similar to the pH in the vagina after sex, promoted HIV-sperm binding and the subsequent rate of sperm-related DC infection.

Source:
Rita Sullivan
Rockefeller University Press

The study shows that in most species males show more consistent, predictable behaviours, particularly in relation to parental care, aggression and risk-taking. Females, on the other hand, are more likely to vary their behaviour. They are also more likely to respond to these traits and therefore seem to be ‘choosier’ about the personality of a potential mate.

The research, which is published in the journal Biological Reviews (18 November 2009) draws on several studies, dating back to 1972. It is the latest study in a growing body of research from a University of Exeter team that links gender personality differences to sexual selection.

The authors believe sexual selection may hold the key to this variation. A concept originally developed by Charles Darwin, sexual selection is the theory that evolutionary traits can be explained by competition between one sex – usually males – for mates and by (female) mate choice. While the physical attributes resulting from sexual selection – from dazzling peacocks tails to over-sized antler horns – are well known, there has been much less of a focus on the impact on personality.

Lead author Dr Wiebke Schuett of the University of Exeter says: “Our study is the first to bring together research about the impact of sexual selection on personality in humans and other animals. Our study suggests that, while males tend to exhibit more pronounced personalities, including more predictable behaviour, in a range of different contexts, females are more receptive to these traits in males. We found a surprising level of similarity across a range of species.”

This paper supports research carried out by the same team, published in the journal Animal Behaviour (February 2009). The team studied the social and feeding behaviours of a population of zebra finches. They found that although the male zebra finches did not explore their environment more than the females, they were more consistent in their exploratory behaviour. The team concluded that males are more likely to be selected as mates if they are consistent in any behaviour that would be beneficial to a partnership and its offspring. This would include finding food or seeing off predators.

Dr Sasha Dall of the University of Exeter, the team leader, says: “This body of research suggests that male personality could have evolved in much the same way as signs of physical attractiveness – to help attract a mate. Scientists have not given the role of sexual selection in shaping animal personality much consideration in the past. We hope that our work will pave the way for further research in this rather overlooked subject.”

Dr Wiebke Schuett was funded by the European Social Fund.

The paper, entitled Sexual Selection and Animal Personality, can be accessed at http://www3.interscience.wiley.com/journal/119878059/issue (DOI: 10.1111/j.1469-185X.2009.00101.x).

Source: Sarah Hoyle
University of Exeter