Adults’ motivation for bringing their children to park playgrounds

Children's independent access to the outdoors is often restricted by parents, making young children dependent on adult motivation for visits. Since access to play in nature can be beneficial to children's development and health, this study examines the accompanying adults’ motivational factors for bringing their children to playgrounds in urban green spaces. The study used on-site questionnaires to collect data in six public park playgrounds in the U.S. and Denmark, to reveal cultural similarities and differences.The results show that the respondents have different motivations for going to a park playground. The Danish respondents find it most important to be together with their children, while the American respondents find it most important that their children are physically active whilst being there. Other results show that different factors can influence both frequency of visits and length of stays. For Danish respondents, location is very important. Pleasing green surroundings and a nearby location tends to result in more frequent visits. All respondents stay longer and visit more often if they like the social atmosphere of the playground. However, male respondents, who are more active with their children than female respondents, have shorter stays if they dislike the variety of play equipment.Based on the results of this paper, suggestions are made as to how designers, planners and park managers can implement the results into practice, with the aim of increasing adults’ motivation for taking their children to park playgrounds.     

Relation of growth hormone response to growth hormone-releasing hormone to estimation of milk production via deuterium oxide dilution in beef cattle

Current methods of estimating milk production in beef cows can be time-consuming, labor-intensive, and subject to high variability. The weigh-suckle-weigh (WSW) method requires repeated separation of offspring from their dams. Machine milking requires that animals be acclimated to the equipment prior to the estimation. The objective of Exp. 1 was to validate a deuterium oxide (D2O) dilution method of estimating milk production in cattle. In Exp. 1, Holstein calves (n = 5) averaging 29+/-2 d of age and 52.6+/-2.5 kg (+/- SE) were used as the model. Blood was collected for baseline D2O measurements followed by an injection of 300 mg D2O/kg BW. Syringes were weighed before and after the injection to gravimetrically determine the dose. Another blood sample was collected after D2O was allowed to equilibrate with body water for 2 h, and on each of the next five consecutive days, prior to feeding. Actual milk intake was measured by disappearance (i.e., amount of milk replacer offered to the calf minus the amount refused). Deuterium oxide in plasma was measured by mass spectrometry and milk intake was computed from the disappearance curve of D2O in blood plasma for each calf. Accumulated milk intake estimated by D2O dilution was highly correlated (y = 0.9x + 0.6; R2 = 0.99; P < 0.001) with actual milk intake. The objectives of Exp. 2 were to determine whether 1) D2O dilution was comparable to a standard measure of milk production in beef heifers and 2) growth hormone (GH) response to GH-releasing hormone (GHRH) in heifers at weaning is predictive of subsequent milk production. Deuterium oxide dilution and WSW were compared using 14 first-calf Angus heifers and their calves. Deuterium oxide dilution was used to estimate milk production of 40 first-calf Angus heifers that had been challenged with GHRH at weaning. Results indicate that the D2O dilution method is correlated (R2 = 0.89; P = 0.04) to the WSW estimation of milk production. Growth hormone response to GHRH in weanling heifers is positively related (R2 = 0.22; P = 0.03) to their subsequent milk production. Deuterium oxide dilution in calves offers an additional approach to the estimation of milk production of the dam in typical beef cattle production settings.     

Effects of hCG Stimulation on Hepatic Activities of Cytochromes P4502E1 and P4502A in Pubertal Male Pigs

The effects of human chorionic gonadotropin (hCG) stimulation on fat skatole concentrations and hepatic activities of cytochromes P4502E1 (CYP2E1) and P4502A (CYP2A) were studied in Landrace and Duroc breeds of entire male pigs. Pigs were divided into four groups: two control groups of each breed, without hCG stimulation (n = 20 for each breed), and two experimental groups of each breed, with hCG stimulation (n = 18 for each breed). Pigs were slaughtered 3 days after hCG stimulation and activities of CYP2E1 and CYP2A were measured in liver homogenate. Activities of both CYP2E1 and CYP2A were lower in hCG‐stimulated pigs than control pigs for both Landrace (p = 0.005 for CYP2E1, p = 0.016 for CYP2A) and Duroc breeds (p = 0.003 for CYP2E1, p = 0.001 for CYP2A), and skatole concentrations in fat were higher in the hCG‐stimulated pigs of both breeds (p < 0.01). For both control and hCG‐stimulated groups, Duroc pigs had lower skatole concentrations than Landrace pigs (p = 0.001 for both groups). The activity of CYP2E1 did not differ significantly between breeds in either the control group or the experimental group (p = 0.233 for control pigs and p = 0.210 for experimental pigs). However, whereas CYP2A activity did not differ significantly between breeds in the control groups (p = 0.181 for CYP2A), in the hCG‐stimulated groups, CYP2A activity was lower in Duroc pigs than in Landrace (p = 0.011). Based on these findings, we conclude that hCG stimulation can suppress hepatic CYP2E1 and CYP2A activities, probably through an increase in the levels of testicular steroids. Between‐breed variations in skatole levels in fat were not related to the activities of CYP2E1 and CYP2A.     

Field evaluation for resistance to the black rot pathogen <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis> in cabbage (<Emphasis Type="Italic">Brassica oleracea</Emphasis>)

Black rot, caused by Xanthomonas campestris pv. campestris, (Xcc), is one of the most serious diseases of crucifers world-wide. Forty-nine genotypes were evaluated for resistance under field conditions in Tanzania after artificial inoculation with Xcc race 1. Open pollinated white cabbage cultivars were generally susceptible, while Portuguese and pointed cabbages exhibited partial resistance. Some F1 white cabbage cultivars were highly susceptible, whereas others exhibited a high level of partial resistance. The most promising of the hybrid cultivars were T-689 F1, Gianty F1, No. 9690 F1, N 66 F1, and SWR-02 F1. Breeding line Badger I-16 exhibited the highest level of resistance of all genotypes. The genotypes accounted for 72.9–75.5% of the variation of the disease severity when assessed on the leaves, and 71.4% of the variation when assessed as internal black rot in heads at harvest. High correlations (equal to or above 0.7) were found between disease severities assessed on leaves three times during the growing season and also with the amount of internal black rot in heads. Leaf loss also was correlated with disease severity. The high genetic determination of the trait and the high correlations between disease assessments indicate that selection for resistance to black rot will be efficient when field screenings are carried out. Evaluation of genotypes for disease severity on leaves during the growing season combined with evaluations of head resistance in the most promising genotypes may be a simple method to select resistant cultivars.     

Pheromone transport and reception in an amphipod

Sexual dimorphism in the second antennae of the amphipod Gammarus duebeni Lilljeborg is connected with the reception in the male of a female sex pheromone transported through the water. Investigations on tritium-labeled specimens were carried out with scintillator and autoradiographic techniques.     

The correlation between Salmonella serology and isolation of Salmonella in Danish pigs at slaughter

In Denmark, a serological Salmonella surveillance programme in finishing pig herds has been in place since 1995. The programme was founded on data from experimental studies, which demonstrated a strong association between Salmonella serology and the prevalence of these bacteria. The current study was carried out in three Danish abattoirs to evaluate the correlation under field conditions. A total of 160 Danish finishing pig herds were included. Seven out of these were examined twice, yielding a total of 167 observations. The herds were selected according to their herd serology based on data from the national surveillance. From each herd, samples were taken from 10 finishers at slaughter. The prevalence of Salmonella bacteria was measured at four sites: (1) caecal-content; (2) carcass surface; (3) pharynx; and (4) caecal lymph nodes. A logistic regression model was constructed for each sampling site. Abattoir, sanitary slaughter and herd seroprevalence were used as explanatory variables. The results demonstrated that there was a strong association between herd serology and the prevalence of Salmonella bacteria measured at three of the sampling sites: caecal-content, pharynx, and carcass surface. For these sites, the odds for being culture-positive for Salmonella varied from 1.3 to 1.5 for each increase of 10% in herd serology (P < 0.0001). For caecal lymph nodes, however, no linear association was found.     

Genetic variation in dieback resistance: growth and survival of Fraxinus excelsior under the influence of Hymenoscyphus pseudoalbidus

The invasive fungal pathogen, Hymenoscyphus pseudoalbidus V. Queloz, has decimated stands of Fraxinus excelsior L. over most of the species' natural distribution area. We assessed crown damage from 2009 to 2014 (at ages 8, 11 and 13) in 43 open-pollinated ash families planted in north-eastern Zealand, Denmark, and confirmed the presence of substantial genetic variation in ash dieback susceptibility. The average crown damage increased in the trial from 61% in 2009 to 66% in 2012 and 72% in 2014, while the estimated heritability was 0.42 in both 2009 and 2012 but increased to 0.53 in 2014. Genetic correlation between assessments was 0.88 between 2009 and 2012 and 0.91 between 2009 and 2014, suggesting fairly good possibilities for early selection of superior genotypes in the presence of high infection levels in the trial. The level of crown damage had strong negative effect on growth and survival. Only 34% of the trees with high levels of damage in 2009 were still alive in 2014, emphasising that high susceptibility is associated with low fitness.     

The role of exotic tree species in Nordic forestry

The selection of suitable tree species is a prerequisite for successful forestry, and the use of exotic species as an alternative to native species is often a relevant option. In this paper, we discuss this option in relation to the present and future wood production in Nordic forestry. We revisit the vegetation and forest history and its implications for the interest in using exotic species. We review to what extent exotic species can contribute to increased economic returns from forest plantings and the potential negative ecological effects associated with introduction of new species. Considering the expected climate changes, we discuss whether and how the increased use of exotic species can contribute to sustained and increased health and productivity of Nordic forests without jeopardising ecological and social values.