Red trap colour of the carnivorous plant Drosera rotundifolia does not serve a prey attraction or camouflage function.

The traps of many carnivorous plants are red in colour. This has been widely hypothesized to serve a prey attraction function; colour has also been hypothesized to function as camouflage, preventing prey avoidance. We tested these two hypotheses in situ for the carnivorous plant Drosera rotundifolia. We conducted three separate studies: (i) prey attraction to artificial traps to isolate the influence of colour; (ii) prey attraction to artificial traps on artificial backgrounds to control the degree of contrast and (iii) observation of prey capture by D. rotundifolia to determine the effects of colour on prey capture. Prey were not attracted to green traps and were deterred from red traps. There was no evidence that camouflaged traps caught more prey. For D. rotundifolia, there was a relationship between trap colour and prey capture. However, trap colour may be confounded with other leaf traits. Thus, we conclude that for D. rotundifolia, red trap colour does not serve a prey attraction or camouflage function.

Dehydroepiandrosterone (DHEA) treatment in vitro inhibits adipogenesis in human omental but not subcutaneous adipose tissue.

Dehydroepiandrosterone (DHEA), a precursor sex steroid, circulates in sulphated form (DHEAS). Serum DHEAS concentrations are inversely correlated with metabolic syndrome components and in vivo/in vitro studies suggest a role in modulating adipose mass. To investigate further, we assessed the in vitro biological effect of DHEA in white (3T3-L1) and brown (PAZ6) preadipocyte cell lines and human primary preadipocytes. DHEA (from 10(-8)M) caused concentration-dependent proliferation inhibition of 3T3-L1 and PAZ6 preadipocytes. Cell cycle analysis demonstrated unaltered apoptosis but indicated blockade at G1/S or G2/M in 3T3-L1 and PAZ6, respectively. Preadipocyte cell-line adipogenesis was not affected. In human primary subcutaneous and omental preadipocytes, DHEA significantly inhibited proliferation from 10(-8)M. DHEA 10(-7)M had opposing effects on adipogenesis in the two fat depots. Subcutaneous preadipocyte differentiation was unaffected or increased whereas omental preadipocytes showed significantly reduced adipogenesis. We conclude that DHEA exerts fat depot-specific differences which modulate body composition by limiting omental fat production.

An evaluation of breastfeeding promotion through peer counseling in Mississippi WIC clinics.

OBJECTIVE: This study evaluates the effectiveness of a peer counseling program at increasing breastfeeding by participants in the Mississippi Special Supplemental Nutrition Program for Women, Infants and Children (WIC). METHODS: Data from the 1989-1993 Pediatric Nutrition Surveillance System were analyzed to compare breastfeeding rates in clinics with and without peer counseling programs. A questionnaire completed by program staff to describe the program in greater detail helped identify characteristics associated with greater success. RESULTS: The incidence of breastfeeding rose from 12.3% to 19.9% in those clinics with peer counseling programs, but only from 9.2% to 10.7% in clinics without a program. Clinics that started a program earlier showed greater changes in breastfeeding incidence. However, the presence of lactation specialists or consultants in the clinic appeared to be more important than the presence of less-trained peer counselors. Peer counselors who spent more than 45 minutes per participant were more effective than those spending less time. CONCLUSIONS: The peer counseling program significantly increased the incidence of breastfeeding, particularly in clinics with lactation specialists and consultants. Success can be enhanced by ensuring that peer counselors spend a great deal of time with the participants.