Comparing sediment equilibrium partitioning and passive sampling techniques to estimate benthic biota PCDD/F concentrations in Newark Bay, New Jersey (U.S.A.)

Sediment and polyethylene sampler-based estimates of polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations in Newark Bay, New Jersey (USA) benthic biota were compared. Biota concentrations based on sediment were estimated using an organic carbon (OC)-water partitioning model and an OC and black carbon (BC)-water dual model. Biota concentrations based on polyethylene were estimated from samplers deployed in the Newark Bay water column and samplers immersed in a sediment/porewater slurry in the laboratory. Porewater samplers provided the best estimates of biota concentrations (within 3.1x), with best results achieved for deposit-feeders (within 1.6x). Polyethylene deployed in deep water also provided good estimates of biota concentrations (within 4x). By contrast, OC-water partitioning overestimated biota concentrations by up to 7x, while OC and BC combined underestimated biota concentrations by up to 13x. We recommend polyethylene for estimating concentrations of hydrophobic organic contaminants in field biota given its simplicity and relatively lower uncertainty compared to sediment equilibrium partitioning

The Earth as an Engineering System: Addressing Sustainability through Science, Technology and Policy

We combine insights from the two emerging fields of engineering systems and sustainability science to develop an analytical approach for understanding and managing coupled natural and human systems. The Earth system is characterized with reference to the attributes of engineering systems (real-world existence, artificiality, dynamic properties, hybrid state, and some human control). We argue that human influences have become so overwhelming that it is impossible to understand global Earth systems without taking into account both technical and social dimensions. Aspects of sustainability systems that fulfill functional types of engineering systems are enumerated with reference to five processes (transporting, transforming, storing, exchanging and controlling) and operands (living organisms, matter, information, energy and money). Building on methods from sustainability science, we introduce the concept of Spatial-Temporal-Functional (STF) analysis for addressing sustainability problems in an engineering systems context. We illustrate this framework with reference to the case of global transport of hazardous chemicals. Our analysis suggests that efforts to address cross-scale problems should focus on enhancing mechanisms for transforming and exchanging in addition to controlling

Influence of Volatile Degassing on Initial Flow Structure and Entrainment During Undersea Volcanic Fire Fountaining Eruptions

Release of dissolved volatiles during submarine fire fountaining eruptions can profoundly influence the buoyancy flux at the vent. Theoretical considerations indicate that in some cases buoyant magma can be erupted prior to fragmentation (~75% vesicle volume threshold). Laboratory simulations using immiscible fluids of contrasting density indicate that the structure of the source flow at the vent depends critically on the relative magnitudes of buoyancy and momentum fluxes as reflected in the Richardson number (Ri). Analogue laboratory experiments of buoyant discharges demonstrate a variety of complex flow structures with the potential for greatly enhanced entrainment of surrounding seawater. Such conditions are likely to favor a positive feedback between phreatomagmatic explosions and volatile degassing that will contribute to explosive volcanism. The value of the Richardson number for any set of eruption parameters (magma discharge rate and volatile content) will depend on water depth as a result of the extent to which the exsolved volatile components can expand

Tracking the Actions and Possessions of Agents

We propose that there is a powerful human disposition to track the actions and possessions of agents. In two experiments, 3‐year‐olds and adults viewed sets of objects, learned a new fact about one of the objects in each set (either that it belonged to the participant, or that it possessed a particular label), and were queried about either the taught fact or an unrelated dimension (preference) immediately after a spatiotemporal transformation, and after a delay. Adults uniformly tracked object identity under all conditions, whereas children tracked identity more when taught ownership versus labeling information, and only regarding the taught fact (not the unrelated dimension). These findings suggest that the special attention that children and adults pay to agents readily extends to include inanimate objects. That young children track an object's history, despite their reliance on surface features on many cognitive tasks, suggests that unobservable historical features are foundational in human cognition.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109337/1/tops12106.pd

The Effect of Age on Short-Term Outcomes After Abdominal Surgery for Pelvic Organ Prolapse

To compare perioperative morbidity and 1-year outcomes of older and younger women undergoing surgery for pelvic organ prolapse (POP). DESIGN : Prospective ancillary analysis. SETTING : Academic medical centers in National Institutes of Health, National Institute of Child Health and Human Development Colpopexy and Urinary Reduction Study. PARTICIPANTS : Women with POP and no symptoms of stress incontinence. INTERVENTION : Abdominal sacrocolpopexy with randomization to receive Burch colposuspension for treatment of possible occult incontinence or not. MEASUREMENTS : Perioperative complications and Pelvic Organ Prolapse Quantification and quality-of-life (QOL) questionnaires (Pelvic Floor Distress Inventory, Pelvic Floor Impact Questionnaire, and Medical Outcomes Study Short-Form Health Survey (SF-36) preoperatively, immediately postoperatively, and 6 weeks and 3 and 12 months postoperatively). RESULTS : Three hundred twenty-two women aged 31 to 82 (21% aged ≥70), 93% white. Older women had higher baseline comorbidity ( P <.001) and more severe POP ( P= .003). Controlling for prolapse stage and whether Burch was performed, there were no age differences in complication rates. Older women had longer hospital stays (3.1±1.0 vs 2.7±1.5 days, P= .02) and higher prevalence of incontinence at 6 weeks (54.7% vs 37.2%, P= .005). At 3 and 12 months, there were no differences in self-reported incontinence, stress testing for incontinence, or prolapse stage. Improvements from baseline were significant on all QOL measures but with no age differences. CONCLUSION : Outcomes of prolapse surgery were comparable between older and younger women except that older women had slightly longer hospital stays.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66257/1/j.1532-5415.2007.01178.x.pd

Acetaldehyde Removal from Indoor Air through Chemical Absorption Using L-Cysteine

The irreversible removal of acetaldehyde from indoor air via a chemical reaction with amino acids was investigated. To compare effectiveness, five types of amino acid (glycine, l-lysine, l-methionine, l-cysteine, and l-cystine) were used as the reactants. First, acetaldehyde-laden air was introduced into aqueous solutions of each amino acid and the removal abilities were compared. Among the five amino acids, l-cysteine solution showed much higher removal efficiency, while the other amino acids solutions didn’t show any significant differences from the removal efficiency of water used as a control. Next, as a test of the removal abilities of acetaldehyde by semi-solid l-cysteine, a gel containing l-cysteine solution was put in a fluororesin bag filled with acetaldehyde gas, and the change of acetaldehyde concentration was measured. The l-cysteine-containing gel removed 80% of the acetaldehyde in the air within 24 hours. The removal ability likely depended on the unique reaction whereby acetaldehyde and l-cysteine rapidly produce 2-methylthiazolidine-4-carboxylic acid. These results suggested that the reaction between acetaldehyde and l-cysteine has possibilities for irreversibly removing toxic acetaldehyde from indoor air

The Search for Invariance: Repeated Positive Testing Serves the Goals of Causal Learning

Positive testing is characteristic of exploratory behavior, yet it seems to be at odds with the aim of information seeking. After all, repeated demonstrations of one’s current hypothesis often produce the same evidence and fail to distinguish it from potential alternatives. Research on the development of scientific reasoning and adult rule learning have both documented and attempted to explain this behavior. The current chapter reviews this prior work and introduces a novel theoretical account—the Search for Invariance (SI) hypothesis—which suggests that producing multiple positive examples serves the goals of causal learning. This hypothesis draws on the interventionist framework of causal reasoning, which suggests that causal learners are concerned with the invariance of candidate hypotheses. In a probabilistic and interdependent causal world, our primary goal is to determine whether, and in what contexts, our causal hypotheses provide accurate foundations for inference and intervention—not to disconfirm their alternatives. By recognizing the central role of invariance in causal learning, the phenomenon of positive testing may be reinterpreted as a rational information-seeking strategy

Chronic and Acute Exposures to the World Trade Center Disaster and Lower Respiratory Symptoms: Area Residents and Workers

Objectives. We assessed associations between new-onset (post–September 11, 2001 [9/11]) lower respiratory symptoms reported on 2 surveys, administered 3 years apart, and acute and chronic 9/11-related exposures among New York City World Trade Center–area residents and workers enrolled in the World Trade Center Health Registry. Methods. World Trade Center–area residents and workers were categorized as case participants or control participants on the basis of lower respiratory symptoms reported in surveys administered 2 to 3 and 5 to 6 years after 9/11. We created composite exposure scales after principal components analyses of detailed exposure histories obtained during face-to-face interviews. We used multivariate logistic regression models to determine associations between lower respiratory symptoms and composite exposure scales. Results. Both acute and chronic exposures to the events of 9/11 were independently associated, often in a dose-dependent manner, with lower respiratory symptoms among individuals who lived and worked in the area of the World Trade Center. Conclusions. Study findings argue for detailed assessments of exposure during and after events in the future from which potentially toxic materials may be released and for rapid interventions to minimize exposures and screen for potential adverse health effects

The First Hour of Extra-galactic Data of the Sloan Digital Sky Survey Spectroscopic Commissioning: The Coma Cluster

On 26 May 1999, one of the Sloan Digital Sky Survey (SDSS) fiber-fed spectrographs saw astronomical first light. This was followed by the first spectroscopic commissioning run during the dark period of June 1999. We present here the first hour of extra-galactic spectroscopy taken during these early commissioning stages: an observation of the Coma cluster of galaxies. Our data samples the Southern part of this cluster, out to a radius of 1.5degrees and thus fully covers the NGC 4839 group. We outline in this paper the main characteristics of the SDSS spectroscopic systems and provide redshifts and spectral classifications for 196 Coma galaxies, of which 45 redshifts are new. For the 151 galaxies in common with the literature, we find excellent agreement between our redshift determinations and the published values. As part of our analysis, we have investigated four different spectral classification algorithms: spectral line strengths, a principal component decomposition, a wavelet analysis and the fitting of spectral synthesis models to the data. We find that a significant fraction (25%) of our observed Coma galaxies show signs of recent star-formation activity and that the velocity dispersion of these active galaxies (emission-line and post-starburst galaxies) is 30% larger than the absorption-line galaxies. We also find no active galaxies within the central (projected) 200 h-1 Kpc of the cluster. The spatial distribution of our Coma active galaxies is consistent with that found at higher redshift for the CNOC1 cluster survey. Beyond the core region, the fraction of bright active galaxies appears to rise slowly out to the virial radius and are randomly distributed within the cluster with no apparent correlation with the potential merger of the NGC 4839 group. [ABRIDGED]Comment: Accepted in AJ, 65 pages, 20 figures, 5 table