Estimation of Fish Biomass Using Environmental DNA

Environmental DNA (eDNA) from aquatic vertebrates has recently been used to estimate the presence of a species. We hypothesized that fish release DNA into the water at a rate commensurate with their biomass. Thus, the concentration of eDNA of a target species may be used to estimate the species biomass. We developed an eDNA method to estimate the biomass of common carp (Cyprinus carpio L.) using laboratory and field experiments. In the aquarium, the concentration of eDNA changed initially, but reached an equilibrium after 6 days. Temperature had no effect on eDNA concentrations in aquaria. The concentration of eDNA was positively correlated with carp biomass in both aquaria and experimental ponds. We used this method to estimate the biomass and distribution of carp in a natural freshwater lagoon. We demonstrated that the distribution of carp eDNA concentration was explained by water temperature. Our results suggest that biomass data estimated from eDNA concentration reflects the potential distribution of common carp in the natural environment. Measuring eDNA concentration offers a non-invasive, simple, and rapid method for estimating biomass. This method could inform management plans for the conservation of ecosystems

Couple’s Relationship After the Death of a Child: a Systematic Review

When a child dies, the parents must address the changes in their relationship as well as the way that these changes affect their individual adjustment. These two perspectives are addressed in this systematic review. Five databases were systematically searched for papers published in English between January 2000 and February 2014. Of the 646 publications, 24 papers met the inclusion criteria. The results suggest that a child’s death can cause cohesive as well as detrimental effects on a couple’s relationship. Variables that may produce differential outcomes for the marital relationship include situational factors, such as the cause and type of death and the child’s age at the time of death; dyad-level factors, such as surviving children, the pre-death characteristics of the relationship, communication and incongruent grieving; and individuallevel factors, such as the family of origin’s processing of trauma, social support, religious affiliation and finding meaning. Aspects such as marital quality and the couple’s interdependence were found to influence each parent’s individual adjustment. Larger, prospective, ethically conducted studies should be implemented to consolidate these findings. Mental health professionals may benefit from a deeper understanding of the risk and protective factors regarding marital adjustment after a child’s death

Morphologic features of the ductus arteriosus after prostaglandin E1administration for ductus-dependent congenital heart defects

Histologic evidence of damage to the ductus arteriosus after the infusion of prostaglandin E1has been reported in neonates with ductus-dependent congenital heart defects. The reported changes suggested structural weakening of the ductus that might render it prone to laceration or rupture. The morphologic features of ductus arteriosi were studied in two groups of neonates with ductus-dependent congenital heart defects. Group 1 (prostaglandin E1group) comprised 12 neonates who received prostaglandin E1and died while receiving it or within 4 days after its administration was discontinued; the mean duration of prostaglandin E1administration was 18 hours (range 30 minutes to 40 hours). Group 2 (control group) comprised 10 neonates who did not receive prostaglandin E1and were matched with group 1 for weight, type of congenital heart defect and age at death.The length of the ductus and its internal diameter at the aortic end were greater in group 1 than in group 2, but the differences were not statistically significant. The internal diameter of the ductus at the pulmonary end was significantly greater in group 1 than in group 2 (p <0.05). Histologic staging of maturation of the ductus (stage 1 being most immature and stage 4 being most mature or functionally closed) showed that the ductus arteriosi of group 1 were significantly more immature than those of group 2. Maturational stage averaged 1.67 ± 0.30 (mean ± standard error of the mean) in group 1 and 3.00 ± 0.29 in group 2 (p <0.0025). Histopathologic abnormalities reported by other investigators were found in only two patients from each group.Cineangiograms obtained at the repeat cardiac catheterization up to 33 months after prostaglandin E1treatment in 28 infants showed no abnormality at the ductus area; in all but 1 infant, the ductus either spontaneously closed or had been surgically ligated uneventfully. In an additional 33 patients, clinical follow-up did not suggest any problems in the ductus. It is concluded that the administration of prostaglandin E1may delay the normal closing process or maturation of the ductus but does not have any significant deleterious morphologic or clinical effect, and that the ductus arteriosus closes normally after prostaglandin E1is discontinued. Prolonged administration of prostaglandin E1)more than 40 hours) may cause the histologic changes observed by others