Maternal Responsiveness and the Development of Directed Vocalizing in Social Interactions

For effective communication, infants must develop the phonology of sounds and the ability to use vocalizations in social interactions. Few studies have examined the development of the pragmatic use of prelinguistic vocalizations, possibly because gestures are considered hallmarks of early pragmatic skill. The current study investigated infant vocal production and maternal responsiveness to examine the relationship between infant and maternal behavior in the development of infants' vocal communication. Specifically, we asked whether maternal responses to vocalizations could influence the development of prelinguistic vocal usage, as has been documented in recent experimental studies exploring the relation between maternal responses and phonological development. Twelve mother–infant dyads participated over a six‐month period (between 8 and 14 months of age). Mothers completed the MacArthur Communicative Development Inventory when infants were 15 months old. Maternal sensitive responses to infant vocalizations in the previous months predicted infants' mother‐directed vocalizations in the following months, rather than overall response rate. Furthermore, mothers' sensitive responding to mother‐directed vocalizations was correlated with an increase in developmentally advanced, consonant–vowel vocalizations and some language measures. This is the first study to document a social shaping mechanism influencing developmental change in pragmatic usage of vocalizations in addition to identifying the specific behaviors underlying development.     

Girls and guys,ghetto and bougie: Metapragmatics,ideology and the management of social identities1

This case study explores the metapragmatic awareness of a young, academically successful, African American, female speaker. It describes some of the identities and orientations that the speaker performs through language and the perceived role of linguistic style in such performances. This study suggests that these linguistic performances are a complex negotiation of ethnicity, gender and class that both draw from and resist the macrosocial indexing of social categories. Further, the understood role of language in the social negotiations of the speaker serves as an illustration of the relationship among metapragmatics, ideology and identity and also highlights the dynamism of identity management as individuals position themselves in allegiance with, or opposition to, various groups that populate their social landscape.     

Gifts, Cash, and Stigma

Each year individuals in the United States transfer between $50 and $72 billion in resources in the form of noncash holiday gifts, despite the fact that holiday gift recipients apparently value their noncash gifts at about 10% less than the prices paid by the givers. We document that cash giving is more likely from givers who tend to give unwanted gifts, indicating that givers are concerned with the utility of their recipients. The rarity of cash gifts can be rationalized by a stigma of cash giving that we are able to parameterize and estimate using a simple structural model.     

Multi‐Echelon Inventory Management under Short‐Term Take‐or‐Pay Contracts

We extend the Clark–Scarf serial multi‐echelon inventory model to include procuring production inputs under short‐term take‐or‐pay contracts at one or more stages. In each period, each such stage has the option to order/process at two different cost rates; the cheaper rate applies to units up to the contract quantity selected in the previous period. We prove that in each period and at each such stage, there are three base‐stock levels that characterize an optimal policy, two for the inventory policy and one for the contract quantity selection policy. The optimal cost function is additively separable in its state variables, leading to conquering the curse of dimensionality and the opportunity to manage the supply chain using independently acting managers. We develop conditions under which myopic policies are optimal and illustrate the results using numerical examples. We establish and use a generic one‐period result, which generalizes an important such result in the literature. Extensions to cover variants of take‐or‐pay contracts are included. Limitations are discussed.     

Young Adults’ Race,Wealth, and Entrepreneurship

This study explored relationships among young adults’ wealth and entrepreneurial activities with emphasis on how these relationships differed among racial and ethnic groups. Using data from the 1997 National Longitudinal Survey of Youth, results indicated that young adults’ (N = 8984) higher accumulated amounts of wealth were associated with pursuing self-employment at higher rates; however, differences emerged when the associations were explored with various types of wealth and within racial and ethnic groups. Black young adults’ greater debt and net worth were associated with their increased likelihoods of self-employment. Among Latino/a young adults, greater liquid assets and net worth were associated with increased likelihoods of self-employment. Wealth was unrelated to white young adults’ self-employment. Wealth appeared to play an outsized role in the self-employment of black and Latino/a young adults compared to that of their white counterparts. In other words, racial and ethnic minority young adults may have a heavier burden for generating their own capital to embark on entrepreneurial activities when mainstream credit markets are unresponsive or inaccessible. Policy implications are discussed.     

Urban ecosystems and sustainable urban development—analysing and assessing interacting systems in the Stockholm region

In order to build competence for sustainability analysis and assessment of urban systems, it is seen as essential to build on models representing urban form, landuse and transportation, urban metabolism, as well as ecological processes. This type of analysis of interacting sub-systems requires an advanced model integration platform, yet open for learning and for further development. Moreover, since the aim is to increase urban experience with ecosystem management in the wide sense, the platform needs to be open and easily available, with high visualisation capacity. For this purpose, the LEAM model was applied to the Stockholm Region and two potential future scenarios were developed, resulting from alternative policies. The scenarios differed widely and the dense urban development of Scenario Compact could be visualised, destroying much of the Greenstructure of Stockholm, while Scenario Urban Nature steered the development more to outer suburbs and some sprawl. For demonstration of the need for further development of biodiversity assessment models, a network model tied to a prioritised ecological profile was applied and altered by the scenarios. It could be shown that the Greenstructure did not support this profile very well. Thus, there is a need for dynamic models for negotiations, finding alternative solutions and interacting with other models. The LEAM Stockholm case study is planned to be further developed, to interact with more advanced transport and land use models, as well as analysing energy systems and urban water issues. This will enable integrated sustainability analysis and assessment of complex urban systems, for integration in the planning process in Stockholm as well as for comparative sustainability studies between different cities, with the goal to build more sustainable urban systems and to increase urban experiences in ecosystem management.     

Salinization alters ecosystem structure in urban stormwater detention ponds

Stormwater ponds now comprise a significant portion of standing water in urban areas. These ponds act to sequester excess run-off and pollutants, such as road salt deicers. While these man-made ponds are not intended to serve as freshwater ecosystems, it is becoming clear that they do provide habitat for many organisms, but we know little of their ecosystem structure, function and interactions with pollutants. From April through June 2009, we surveyed 8 stormwater ponds in the Red Run Watershed, Baltimore County, Maryland, USA to describe patterns in aquatic food webs associated with a gradient in road salt inputs. Periphyton, phytoplankton and zooplankton samples were collected from each pond every 4–6 weeks. Specific conductance, a measure of chloride salt loading, among the 8 ponds varied widely throughout the survey, ranging from 99 μS cm⁻¹ to 19,320 μS cm⁻¹. Low (average = 404 +/− 82.6 (SE) μS cm⁻¹) and medium (average = 1749 +/− 267 (SE) μS cm⁻¹) conductance ponds had lower algal biomass and higher densities of zooplankton taxa relative to high (average = 7231 +/− 2143 (SE) μS cm⁻¹) conductance ponds, which were largely devoid of all zooplankton through the end of May. The observed decline in zooplankton density along an increasing chloride gradient is consistent with experimental results of road deicer effects, suggesting algal resources are possibly freed from grazing pressure as zooplankton consumers are negatively impacted by road salt exposure. Our results highlight the potential for both direct and indirect effects of road deicers on freshwater communities.