Carbon storage in rare ecosystems relative to their encroaching forests in western Lower Michigan.

Rising atmospheric carbon dioxide levels are impacting global temperatures, ecological systems, and human societies. Natural carbon sequestration through the conservation of soil and native ecosystems may slow or reduce the amount of CO2 in the atmosphere, and thus slow or mitigate the rate of global warming. Most of the research investigating carbon sequestration in natural systems occurs in forested ecosystems, however rare ecosystems such as coastal plain marshes and wet-mesic sand prairie collectively may serve as significant carbon sinks. Our objectives were to measure and assess the importance of carbon sequestration in three rare ecosystems (oak-pine barrens, coastal plain marsh, and wet-mesic sand prairie) in western Lower Michigan. We measured carbon in standing vegetation, dead organic matter, and soils within each ecosystem and adjacent encroaching forested areas. Driven by tree carbon, total carbon stocks in encroaching areas were greater than in intact rare ecosystems. Soil organic carbon was greater in all intact ecosystems, though only significantly so in coastal plain marsh. Principal components analysis explained 72% of the variation and revealed differences between intact ecosystems and their encroaching areas. Linear models using the ratio of red to green light reflectance successfully predicted SOC in intact coastal plain marsh and wet-mesic sand prairie. Our results infer the importance of these rare ecosystems in sequestering carbon in soils and support the need to establish federal or state management practices for the conservation of these systems.

Are little brown bats (Myotis lucifugus) impacted by dietary exposure to microcystin?✰.

The cyanobacterium, Microcystis aeruginosa, can produce the hepatotoxin microcystin. When toxic M. aeruginosa overwinters in the sediments of lakes, it may be ingested by aquatic insects and bioaccumulate in nymphs of Hexagenia mayflies. When volant Hexagenia emerge from lakes to reproduce, they provide an abundant, albeit temporary, food source for many terrestrial organisms including bats. Little brown bats, Myotis lucifugus, feed opportunistically on aquatic insects including Hexagenia. To determine if microcystin moves from aquatic to terrestrial ecosystems via trophic transfer, we combined a dietary analysis with the quantification of microcystin in bat livers and feces. In June 2014, coincident with the local Hexagenia emergence, bat feces were collected from underneath a maternity roost near Little Traverse Lake (Leelanau County, Michigan, USA). Insects in the diet were identified via molecular analyses of fecal pellets from the roost and from individual bats. Livers and feces were collected from 19 female M. lucifugus, and the concentrations of microcystin in these liver tissues and feces were measured using an enzyme-linked immunosorbent assay (ELISA) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). We show that the majority of the bats' diets consisted of aquatic insects and that microcystin was detected in high concentrations (up to 129.9 µg/kg dw) in the bat feces by ELISA. Histopathological examination of three bat livers with the highest concentrations of microcystin showed no evidence of phycotoxicosis, indicating that M. lucifugus may not be immediately affected by the ingestion of microcystin. Future work could examine whether bats suffer delayed physiological effects from ingestion of microcystin.

Evaluating toxicity risk in sediments after remediation at a Superfund megasite using a Triad approach.

The Pine River downstream of the Velsicol Superfund site has been contaminated with various hydrophobic organic pollutants for more than 50 years. Remediation and sediment dredging near the site began in spring of 1999, and was completed in 2006. In 2011, the Michigan Department of Environmental Quality completed a baseline assessment report long-term monitoring plan for the Pine River. However, there has been limited assessment of the benthic community since this evaluation. The objective of this research was to evaluate the risk of Pine River sediment to aquatic macroinvertebrates downstream from the Superfund site after decades of degradation and dredging using the Triad approach. Three sites were selected downstream from the Superfund site, and an upstream reference site was used. At each site, macroinvertebrates surveys were conducted and sediments were collected for chemical analysis of DDT (1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane) and its degradation products and for laboratory toxicity testing for mortality and sublethal effects using Hyalella azteca and Chironomus dilutus. Sediment concentrations of DDT, DDD, and DDE were below levels expected to cause toxicity, and there was no observed toxicity in laboratory tests. Additionally, there were no statistically significant differences in richness, richness of Ephemeroptera, Plecoptera, and Trichoptera (EPT) species, total EPT abundance, percent EPT, or percent dominant taxa between the reference site and the downstream sites. There was an observed decrease in abundance of macroinvertebrate taxa at all downstream sites and a shift in macroinvertebrate structure when comparing the reference with most impaired sites. Although the sites downstream of the Superfund site remain different than the upstream control, there are improvements in species composition and abundance. However, more research is needed to evaluate the potential effects on ecosystem function.

Lessons learnt from school-based health promotion projects in low- and middle-income countries.

BACKGROUND: Non-communicable diseases (NCD) are now the leading cause of death worldwide. As habits and lifestyle are established in childhood and adolescence, targeting school children before they develop unhealthy habits offers a window of opportunity to halt and reverse the emerging NCD epidemic. However, few experiences from school interventions in low- and middle-income countries have been collected. Therefore, the aim of this study was to review experiences of implementing school-based health promotion interventions to identify barriers and recommendations for future interventions. METHODS: A qualitative investigation of 17 school-based health promotion interventions in low- and middle-income countries was conducted. Data were collected through questionnaires (15 project leaders) and in-depth interviews with nine project leaders. The data from the questionnaires and interviews was triangulated and analysed using content analysis, where themes and categories emerging from the material were explored. RESULTS: Three key themes emerged from the data: 1) policy environment and stakeholder engagement, 2) health education sessions, and 3) practical health promotion activities. The themes explored the experiences and lessons learned from 17 school-based health promotion projects in low- and middle-income countries. Stakeholders at different administrative levels were important for the projects; however, stakeholders close to implementation were seen to be more engaged. Most projects conducted traditional health education lectures, which formed the basis of their intervention. Promotion of physical activity and healthy eating through participatory approaches were identified; however, barriers such as lack of areas suitable for physical activity and lack of healthy food alternatives in schools can obstruct the successful implementation of interventions. CONCLUSIONS: This study has documented experiences with school-based health promotion in low- and middle-income countries, and has shown that schools can play an important role in facilitating NCD-related behavioural change in children. The study recommends increased emphasis on a whole-school approach where activities focusing on individual behavioural change are supported by interventions improving the structural environment.

Bulky aromatic amino acids increase the antibacterial activity of 15-residue bovine lactoferricin derivatives.

A model peptide, FKCRRWQWRMKKLGA, residues 17-31 of bovine lactoferricin, has been subjected to structure-antibacterial activity relationship studies. The two Trp residues are very important for antibacterial activity, and analogue studies have demonstrated the significance of the size, shape and aromatic character of the side chains. In the current study we have replaced Trp residues in the model peptide with bulky aromatic amino acids to elucidate further the importance of size and shape. The counterproductive Cys residue in position 3 was also replaced by these aromatic amino acids. The largest aromatic amino acids employed resulted in the most active peptides. The peptides containing these hydrophobic residues were generally more active against Staphylococcus aureus than against Escherichia coli, indicating that the bacterial specificity as well as the antibacterial efficiency can be altered by employing large hydrophobic aromatic amino acid residues.