Public Parks and Wellbeing in Urban Areas of the United States

Sustainable development efforts in urban areas often focus on understanding and managing factors that influence all aspects of health and wellbeing. Research has shown that public parks and green space provide a variety of physical, psychological, and social benefits to urban residents, but few studies have examined the influence of parks on comprehensive measures of subjective wellbeing at the city level. Using 2014 data from 44 U.S. cities, we evaluated the relationship between urban park quantity, quality, and accessibility and aggregate self-reported scores on the Gallup-Healthways Wellbeing Index (WBI), which considers five different domains of wellbeing (e.g., physical, community, social, financial, and purpose). In addition to park-related variables, our best-fitting OLS regression models selected using an information theory approach controlled for a variety of other typical geographic and socio-demographic correlates of wellbeing. Park quantity (measured as the percentage of city area covered by public parks) was among the strongest predictors of overall wellbeing, and the strength of this relationship appeared to be driven by parks’ contributions to physical and community wellbeing. Park quality (measured as per capita spending on parks) and accessibility (measured as the overall percentage of a city’s population within ½ mile of parks) were also positively associated with wellbeing, though these relationships were not significant. Results suggest that expansive park networks are linked to multiple aspects of health and wellbeing in cities and positively impact urban quality of life.     

Modifications in Rat Plasma Proteome after Remote Ischemic Preconditioning (RIPC) Stimulus: Identification by a SELDI-TOF-MS Approach

Remote ischemic preconditioning’s (RIPC) ability to render the myocardium resistant to subsequent prolonged ischemia is now clearly established in different species, including humans. Strong evidence suggests that circulating humoral mediators play a key role in signal transduction, but their identities still need to be established. Our study sought to identify potential circulating RIPC mediators using a proteomic approach. Rats were exposed to 10-min limb ischemia followed by 5- (RIPC 5′) or 10-min (RIPC 10′) reperfusion prior to blood sampling. The control group only underwent blood sampling. Plasma samples were isolated for proteomic analysis using surface-enhanced laser desorption and ionization - time of flight - mass spectrometry (SELDI-TOF-MS). A total of seven proteins, including haptoglobin and transthyretin, were detected as up- or down-regulated in response to RIPC. These proteins had previously been identified as associated with organ protection, anti-inflammation, and various cellular and molecular responses to ischemia. In conclusion, this study indicates that RIPC results in significant modulations of plasma proteome.     

Clonal growth of primary cultures of rabbit ear chondrocytes in a lipid-supplemented defined medium

Clonal growth of primary cultures of rabbit ear chondrocytes in a defined medium without serum or other undefined additives has been achieved. The clonal inoculum is a suspension of fully differentiated chondrocytes prepared by collagenase digestion of rabbit ear cartilage and used with no prior adaptation or selection in culture. When inoculated into medium MCDB 104 supplemented with 100 ng/ml fibroblast growth factor (FGF), 1 microgram/ml insulin, and 5 micrograms/ml of a lipid supplement previously developed for human fibroblasts, the isolated chondrocytes undergo clonal multiplication to form large colonies of epithelial-like cells. Colonies grown in the defined medium for 14 days accumulate at their centers refractile cartilage-like matrix that is stained by acidified Alcian green, although the amount is significantly less than with undefined additives. This system opens the way for detailed studies, in a defined background medium, of factors that regulate phenotypic expression of cartilage-like differentiated properties.     

Complex additivity of the effects of suppressor mutations in differing protein environments.

In the alpha-complementation of beta-galactosidase, a defective beta-galactosidase protein interacts with an autologous peptide fragment (alpha-peptide) to restore enzymatic activity. Within a specific site of a defective alpha-peptide we have previously isolated a large number of mutations, many of which suppress the functional defect. The alpha-peptide was originally defective due to both insertional and substitutional sequence alterations near its N-terminus, which provided an increase in the sensitivity of detection of (suppressor) secondary mutations which conferred improved function. We have now studied the effects of the suppressor mutations when the primary deleterious mutations are sequentially reversed. This was done in intact beta-galactosidase, as we have shown that mutations in the alpha-peptide have related functional effects in the whole protein. Evidence was obtained showing that the effects of at least some suppressor mutations were not simply additive when the mutations are placed into the original wild-type protein environment. One suppressor appeared to function less effectively in the normal environment, while another when tested in the same manner functioned at a relatively increased level. This failure to show simple additivity may be attributable to the physical proximity of the original defective mutations and the introduced suppressors. Nevertheless, even in such cases it may be feasible to use a defective protein as a sensitive starting point for the identification of mutations which improve the wild-type protein.     

The initial expression and patterned appearance of tenascin in scutate scales is absent from the dermis of the scaleless (sc/sc) chicken.

Morphogenesis of the anterior metatarsal skin (scutate scale region), from 9.5 to 12 days of development, results in the formation of orderly patterned scale ridges. It is after the initial formation of the Definitive Scale Ridge that the characteristic outer and inner epidermal surfaces differentiate. The hard, plate-like beta stratum, with its unique beta keratins, characterizes the epidermis of the outer surface, while the epidermis of the inner surface elaborates an alpha stratum. The anterior metatarsal region of the scaleless mutant does not undergo scale morphogenesis. Therefore, scale ridges do not form nor do the outer and inner epidermal surfaces with their characteristic beta and alpha strata. We have found that the extracellular matrix molecule, tenascin, first appears in the scutate scale dermis at 12 days of development when the scale ridge is established. Tenascin is found in the dermis only under the scale ridge and is not associated with the dermal-epidermal junction. Tenascin is not found in scaleless anterior metatarsal dermis at this time. As outgrowth of the Definitive Scale Ridge takes place, tenascin distribution correlates closely with the formation of the outer epidermal surface of each scale ridge. By 16 days of development tenascin is also found in close association with the dermal-epidermal junction. Tenascin does not appear in scaleless anterior metatarsal dermis until 16 days of development and then it is randomly and sparsely distributed at the dermal-epidermal junction. Tenascin's initial appearance and pattern of distribution in the scutate scale dermis and its abnormal expression in the scaleless dermis suggest that morphogenesis plays a significant role in regulation of its expression.     

Damage caused by low-density exotic herbivore populations: the impact of introduced European rabbits on marsupial herbivores and Allocasuarina and Bursaria seedling survival in Australian coastal shrubland

The impact of over-abundant exotic herbivores is well recognised, but their impact at low population densities is poorly understood. This study examined interactions between European rabbits and native herbivores, and their impact on seedling recruitment in coastal South Australia, 2 years after rabbit haemorrhagic disease (RHD) had reduced rabbit density to 4.48 rabbits ha⁻¹. Rabbit density was further reduced to 0.44 rabbits ha⁻¹ in replicated experimental treatments. Rabbit control reduced total grazing pressure by 39% despite compensatory grazing increases of >100% for both western grey kangaroos and common wombats. Rabbit control slowed the rate of grazing and mortality for planted drooping sheoak and sweet bursaria seedlings, but few survived for 12 months: 0 and 3% of sheoak, in untreated areas and rabbit control treatments, respectively, and 3 and 11% of bursaria, respectively. Planted sheoaks survived well if protected by rabbit-proof netting (60%). Within treatments, seedling grazing and survival rates were negatively correlated with rabbit density but kangaroo and wombat density had no measurable effect. We conclude that RHD may briefly have reduced rabbit densities enough to allow recruitment of bursaria but that sheoak require much lower rabbit densities than those provided by existing biological control agents. If left unaddressed, rabbit grazing could ultimately lead to the loss of sheoaks throughout most of their current range, irrespective of other attempts to conserve them. More generally, these data show how species-specific damage caused by low-density exotic herbivore populations may occur in the presence of more abundant but less-damaging native herbivores.     

Microtopographic Cues for Settlement of Zoospores of the Green Fouling Alga Enteromorpha

Enteromorpha , the most important macroalga that fouls ships, produces very large numbers of swimming spores that respond to a number of settlement cues. Responses to topographic cues have been investigated using surfaces with defined microtopographies fabricated from polydimethyl siloxane elastomer (PDMS). The topographic features were based on two designs, (a) a series of 5 or 1.5 w m deep valleys with valley floors and ridges varying between 5 and 20 w m, and (b) pillars of 5 w m diameter and 5 or 1.5 w m height, spaced 5-20 w m apart. The features were arranged in blocks to provide the swimming spores with a 'choice' of where to settle. Swimming spores settled preferentially in the valleys and against the pillars. The number of spores that settled increased very substantially as the width of the valley decreased. The majority of spores settled in the angle between the valley floor and sidewall. Lower numbers settled on the surfaces with lower profile features. Silica beads of similar dimension to the spore body were used to determine whether the spatial relationships between settled spores and the topographic features were a consequence of active settlement behaviours. The results are discussed in relation to the energy needs for spores to adhere to various surface features.