Fiedel S.J.,Louis Berger Group Inc.
The 1300-year-long Younger Dryas cold reversal (12,900-11,600 cal BP) is seen most clearly in Greenland ice cores. Contemporaneous changes of climate and environment in more southerly regions were variably expressed. The precise timing of the abrupt Younger Dryas onset is still uncertain. It was linked to a sudden increase in 14C manifest as a "cliff" where 14C dates drop from 11,000 to 10,600 radiocarbon years BP within a century of real time, followed by a long plateau. Changes in ocean and/or atmospheric circulation or solar radiation, and even a comet impact have been proposed as triggers, but the abruptness and severity of YD onset still elude explanation. © 2011 Elsevier Ltd and INQUA. Source
Kisia D.,Louis Berger Group Inc.
Transportation Research Record
Airport employees often account for a substantial share of daily airport access trips, yet current planning for airport landside access in the United States focuses almost exclusively on identifying and addressing the needs of air passengers. Airport worker travel patterns are normally studied by using the standard journey-to-work components of travel demand models and generally do not capture the unique factors affecting this group's commuting behavior. The Port Authority Trans-Hudson (PATH) commissioned a preliminary study evaluating the economic feasibility of extending PATH rail service to Newark Liberty International Airport, New Jersey. An empirical analysis of survey data collected during this effort suggests that the traditional travel demand model approaches to studying airport worker commuting patterns often mischaracterize the travel patterns and attitudes of a large airport access market segment. This research finds that the omission of airport worker input in the planning process is likely to result in the overestimation of public transit demand and may only exacerbate the optimism bias that has typically affected rail transportation investments in the United States. Source
Chatman D.G.,University of California at Berkeley |
Tulach N.K.,Rutgers University |
Kim K.,Louis Berger Group Inc.
Economic benefits are sometimes used to justify transport investments. Such was the case with the River Line of southern New Jersey, USA, which broke ground in 2000 and began operating in 2004. Recently, the line has been performing near full capacity and there is evidence that it has spurred development. Disaggregate data on owned-home appreciation are used to investigate the initial economic impacts of the line, looking carefully at non-linearity in the appreciation gradient, differential effects of station ridership and parking, redistribution of property appreciation gains and differences by property and neighbourhood type. At this time, the net impact of the line on the owned housing market is neutral to slightly negative. While lower-income census tracts and smaller houses seem to appreciate near the station, this may be a value transfer from farther-away properties not favoured with access. Few studies have previously looked for such effects. © 2011 Urban Studies Journal Limited. Source
Wagenfeld A.,Western Michigan University |
Roy-Fisher C.,Studio Sprout |
Mitchell C.,Louis Berger Group Inc.
Purpose: Providing veterans diagnosed with post-traumatic stress disorder (PTSD), their families, and staff opportunities to experience physical and mental restoration in outdoor environments designed based on evidence is important. The purpose of this paper is to explore the relationship between evidence-based collaborative design of outdoor environments and their potential capacity to contribute to a veteran's journey to wellness. Design/methodology/approach: There is no existing precedent in the peer-reviewed literature linking positive health outcomes associated with outdoor environments to veterans with PTSD. This review of the literature is conceptualized as a means to extrapolate these benefits to this unique population. Findings: Access to nature improves physiological and psychological health outcomes. A collaborative design approach ensures that design outcomes meet specific populations' needs. Practical implications: Many service-members are reluctant to seek traditional treatments for PTSD, fearing threat to future military service and limited available resources. Alternative treatments, access to sensitively designed outdoor environments and/or a re-examination of traditional treatments and the environments in which they are provided supports best practice approaches to ameliorating the debilitating effects of this disorder. Social implications: An integrated design approach blending the skills of landscape architecture and occupational therapy is key to achieve design outcomes that support the healing process to meet the needs of this vulnerable population. Originality/value: An inter and/or trans-disciplinary team approach to design and programming of outdoor environments for veterans with PTSD blends landscape architecture with occupational therapy to ensure both form and function are achieved, thus positing positive health outcomes. © Emerald Group Publishing Limited. Source
Gbondo-Tugbawa S.S.,Louis Berger Group Inc. |
McAlear J.A.,Booz Allen Hamilton |
Driscoll C.T.,Syracuse University |
Sharpe C.W.,OBrien and Gere
Concerns over the fate and bioaccumulation of mercury (Hg) inputs to Onondaga Lake, a hypereutrophic lake in central New York, prompted an investigation into the concentrations and fluxes of Hg discharge from the Onondaga County Metropolitan Wastewater Treatment Plant (METRO WWTP). Discharge of methyl Hg (MeHg) is of concern because it is the form of Hg that readily bioaccumulates along the aquatic food chain. This study incorporated clean protocols for sampling and Hg analysis to evaluate: seasonal patterns in the concentrations of total Hg (THg) and MeHg in the WWTP unit processes; the production of MeHg within the unit processes of the WWTP; the overall fate of THg and MeHg within the WWTP; and the relative impact of the Hg discharged from the WWTP to Onondaga Lake. Concentrations of THg (range: 80-860 ng/L) and MeHg (0.7-17 ng/L) in raw sewage were highly variable, with higher concentrations observed in the summer months. The dynamics of THg though the WWTP were correlated with total suspended solids (TSS). As a result, the majority of the THg removal (55%) occurred during primary treatment. Overall, about 92% of the THg entering the plant was removed as sludge, with volatilization likely a minor component of the overall Hg budget. The transformation of MeHg through the plant differed from THg in that MeHg was not correlated with TSS, and displayed strong seasonal differences between winter (November to April) and summer (May-October) months. During the summer months, substantial net methylation occurred in the activated sludge secondary treatment, resulting in higher MeHg concentrations in secondary effluent. Net demethylation was the dominant mechanism during tertiary treatment, resulting in removal of substantial MeHg from the secondary effluent. The overall MeHg removal efficiency through the plant was about 70% with more efficient removal during summer months. Sediment trap collections made below the epilimnion of Onondaga Lake indicated average deposition rates of 12 μg/m2-day for THg and 0.33 μg/m2-day for MeHg. These deposition rates are more than an order of magnitude higher than the thermocline area normalized external loads from METRO effluent (0.85 μg/m2-day for THg, 0.05 μg/m2-day for MeHg). Our findings indicate that the impact of the discharge from METRO is relatively small, contributing about 10-15% of Hg to the total gross Hg input to the hypolimnion of the lake. © 2010 Elsevier Ltd. All rights reserved. Source