Older Adults at Increased Risk as Pedestrians in Victoria,Australia: An Examination of Crash Characteristics and Injury Outcomes

Objectives: Engaging in active transport modes (especially walking) is a healthy and environmentally friendly alternative to driving and may be particularly beneficial for older adults. However, older adults are a vulnerable group: they are at higher risk of injury compared with younger adults, mainly due to frailty and may be at increased risk of collision due to the effects of age on sensory, cognitive, and motor abilities. Moreover, our population is aging, and there is a trend for the current cohort of older adults to maintain mobility later in life compared with previous cohorts. Though these trends have serious implications for transport policy and safety, little is known about the contributing factors and injury outcomes of pedestrian collision. Further, previous research generally considers the older population as a homogeneous group and rarely considers the increased risks associated with continued ageing.

Method: Collision characteristics and injury outcomes for 2 subgroups of older pedestrians (65–74 years and 75+ years) were examined by extracting data from the state police–reported crash dataset and hospital admission/emergency department presentation data over the 10-year period between 2003 and 2012. Variables identified for analysis included pedestrian characteristics (age, gender, activity, etc.), crash location and type, injury characteristics and severity, and duration of hospital stay. A spatial analysis of crash locations was also undertaken to identify collision clusters and the contribution of environmental features on collision and injury risk.

Results: Adults over 65 years were involved in 21% of all pedestrian collisions. A high fatality rate was found among older adults, particularly for those aged 75 years and older: this group had 3.2 deaths per 100,000 population, compared to a rate of 1.3 for 65- to 74-year-olds and 0.7 for adults below 65 years of age. Older pedestrian injuries were most likely to occur while crossing the carriageway; they were also more likely to be injured in parking lots, at driveway intersections, and on sidewalks compared to younger cohorts. Spatial analyses revealed older pedestrian crash clusters on arterial roads in urban shopping precincts. Significantly higher rates of hospital admissions were found for pedestrians over the age of 75 years and for abdominal, head, and neck injuries; conversely, older adults were underrepresented in emergency department presentations (mainly lower and upper extremity injuries), suggesting an increased severity associated with older pedestrian injuries. Average length of hospital stay also increased with increasing age.

Conclusion: This analysis revealed age differences in collision risk and injury outcomes among older adults and that aggregate analysis of older pedestrians can distort the significance of risk factors associated with older pedestrian injuries. These findings have implications that extend to the development of engineering, behavioral, and enforcement countermeasures to address the problems faced by the oldest pedestrians and reduce collision risk and improve injury outcomes.     

Predicting Opportunities for Greening and Patterns of Vegetation on Private Urban Lands

This paper examines predictors of vegetative cover on private lands in Baltimore, Maryland. Using high-resolution spatial data, we generated two measures: “possible stewardship,” which is the proportion of private land that does not have built structures on it and hence has the possibility of supporting vegetation, and “realized stewardship,” which is the proportion of possible stewardship land upon which vegetation is growing. These measures were calculated at the parcel level and averaged by US Census block group. Realized stewardship was further defined by proportion of tree canopy and grass. Expenditures on yard supplies and services, available by block group, were used to help understand where vegetation condition appears to be the result of current activity, past legacies, or abandonment. PRIZM™ market segmentation data were tested as categorical predictors of possible and realized stewardship and yard expenditures. PRIZM™ segmentations are hierarchically clustered into 5, 15, and 62 categories, which correspond to population density, social stratification (income and education), and lifestyle clusters, respectively. We found that PRIZM 15 best predicted variation in possible stewardship and PRIZM 62 best predicted variation in realized stewardship. These results were further analyzed by regressing each dependent variable against a set of continuous variables reflective of each of the three PRIZM groupings. Housing age, vacancy, and population density were found to be critical determinants of both stewardship metrics. A number of lifestyle factors, such as average family size, marriage rates, and percentage of single-family detached homes, were strongly related to realized stewardship. The percentage of African Americans by block group was positively related to realized stewardship but negatively related to yard expenditures.     

An Ecology of Prestige in New York City: Examining the Relationships Among Population Density,Socio-economic Status,Group Identity,and Residential Canopy Cover

Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use diverse data sources including the City’s property database, time-series demographic and socio-economic data from the US Census, and land cover data from the University of Vermont’s Spatial Analysis Lab (SAL). These data are analyzed using a multi-model inferential, spatial econometrics approach. We also examine the distribution of vegetation within distinct market categories using Claritas’ Potential Rating Index for Zipcode Markets (PRIZM?) database. These categories can be disaggregated, corresponding to the four social theories. We compare the econometric and categorical results for validation. Models associated with ecology of prestige theory are more effective for predicting the distribution of vegetation. This suggests that private, residential patterns of vegetation, reflecting the consumption of environmentally relevant goods and services, are associated with different lifestyles and lifestages. Further, our spatial and temporal analyses suggest that there are significant spatial and temporal dependencies that have theoretical and methodological implications for understanding urban ecological systems. These findings may have policy implications. Decision makers may need to consider how to most effectively reach different social groups in terms of messages and messengers in order to advance land management practices and achieve urban sustainability.     

Microbial biomass yield and turnover in soil biodegradation tests: carbon substrate effects

Most of the standardized biodegradation tests used to assess the ultimate biodegradation of environmentally degradable polymers are based solely on the determination of net evolved carbon dioxide. However, under aerobic conditions, it has to be considered that heterotrophic microbial consortia metabolize carbon substrates both to carbon dioxide and in the production of new cell biomass. It is generally accepted that in the relatively short term, 50% of the carbon content of most organic substrates is converted to CO₂, with the remaining carbon being assimilated as biomass or incorporated into humus. The latter is particularly important when the metabolism of the organic matter occurs in a soil environment. A straightforward relationship between the free-energy content of a carbon substrate (expressed as the standard free-energy of combustion) and its propensity for conversion to new microbial biomass rather than mineralization to CO₂ has been established. This can potentially lead to underestimation of biodegradation levels of test compounds, especially when they consist of carbon in a fairly low formal oxidation state and relatively high free-energy content. In the present work, the metabolism of different kind of carbon substrates, especially in soil, is reviewed and compared with our own experimental results from respirometric tests. The results show that conversion of highly oxidized materials, such as the commonly used reference materials, cellulose or starch, to CO₂ may be significantly overestimated. The addition of glucosidic material to soil leads to greatly increased respiration and is accompanied by a very low conversion to biomass or humic substances. In contrast, relatively less oxidized substrates metabolize more slowly to give both CO₂ and biomass to an extent which may be significantly underestimated if glucosidic materials are used as the reference. The need for an overall carbon balance taking into account both the carbon immobilized as biomass and that volatized as CO₂ must be considered in standard respirometric procedures for assessing the biodegradability of slowly degrading macromolecules.     

Impacts of Mauritia flexuosa degradation on the carbon stocks of freshwater peatlands in the Pastaza-Marañón river basin of the Peruvian Amazon

Tropical peat swamp forests (PSF) are characterized by high quantities of carbon (C) stored as organic soil deposits due to waterlogged conditions which slows down decomposition. Globally, Peru has one of the largest expanse of tropical peatlands, located primarily within the Pastaza-Marañón river basin in the Northwestern Peru. Peatland forests in Peru are dominated by a palm species—Mauritia flexuosa, and M. flexuosa-dominated forests cover ~?80% of total peatland area and store ~?2.3 Pg C. However, hydrologic alterations, land cover change, and anthropogenic disturbances could lead to PSF’s degradation and loss of valuable ecosystem services. Therefore, evaluation of degradation impacts on PSF’s structure, biomass, and overall C stocks could provide an estimate of potential C losses into the atmosphere as greenhouse gases (GHG) emissions. This study was carried out in three regions within Pastaza-Marañón river basin to quantify PSF’s floristic composition and degradation status and total ecosystem C stocks. There was a tremendous range in C stocks (Mg C ha^?1) in various ecosystem pools—vegetation (45.6–122.5), down woody debris (2.1–23.1), litter (2.3–7.8), and soil (top 1 m; 109–594). Mean ecosystem C stocks accounting for the top 1 m soil were 400, 570, and 330 Mg C ha^?1 in Itaya, Tigre, and Samiria river basins, respectively. Considering the entire soil depth, mean ecosystem C stocks were 670, 1160, and 330 Mg C ha^?1 in Itaya, Tigre, and Samiria river basins, respectively. Floristic composition and calcium to Magnesium (Ca/Mg) ratio of soil profile offered evidence of a site undergoing vegetational succession and transitioning from minerotrophic to ombrotrophic system. Degradation ranged from low to high levels of disturbance with no significant difference between regions. Increased degradation tended to decrease vegetation and forest floor C stocks and was significantly correlated to reduced M. flexuosa biomass C stocks. Long-term studies are needed to understand the linkages between M. flexuosa harvest and palm swamp forest C stocks; however, river dynamics are important natural drivers influencing forest succession and transition in this landscape.

     

Molecular biomarkers of energy metabolism in mussels under anthropogenic pollution of Peter the Great Bay, the Sea of Japan

The functional state of the indicator species, the Gray mussel Crenomytilus grayanus (Bivalvia), has been analyzed in five areas of Peter the Great Bay exposed to anthropogenic pollution. The following indices of the state of mussels have been used: molecular biomarkers of energy metabolism—Na⁺,K⁺-ATPase, Mg²⁺-ATPase, and total ATPase activity—as well as the level of lipid peroxidation (LPO) and glutathione concentration in the hepatopancreas, gills, and gonads of mussels. The activity of ATPases, LPO level, and glutathione concentration significantly change in mussels from polluted areas relative to those in mussels from a conventionally unpolluted area (a bay in the Far Eastern State Marine Reserve). The molecular biomarkers used in the study provide reliable information on animal metabolism in impact areas. With consideration of the data obtained, it is concluded that the state of mussels in polluted areas is impaired.     

Characteristics of microorganisms isolated from technogenic soils of the Kama region

Microorganisms capable of degrading monocyclic and polycyclic aromatic hydrocarbons and several chlorinated aromatic compounds were isolated from soils polluted with industrial waste from chemical plants. They were identified as representatives of the genera Pseudomonas, Flavobacterium, Alcaligenes, Rhodococcus, Microbacterium, Cellulomonas, Arthrobacter, and Brevibacterium. Among them, bacteria capable of utilizing xenobiotics in a wide range of ambient temperatures and pH and in the presence of high sodium chloride concentrations were revealed.