4,975 research outputs found
Mercury in the environs of the north slope of Alaska
The analysis of Greenland ice suggests that the flux of mercury from the continents
to the atmosphere has increased in recent times, perhaps partly as a result of the many of
manâs activities that effect an alteration of terrestrial surfaces. Upon the exposure of fresh
crustal matter, the natural outgassing of mercury vapor from the earthâs surface could be
enhanced.
Accordingly, mercury was measured in a variety of environmental materials gathered
from the North Slope of Alaska to provide background data prior to the anticipated increase
of activity in this environment. The materials were collected during the U. S. Coast Guard
WEBSEC 72-73 cruises as well as through the facilities provided by Naval Arctic Research
Laboratory in the spring of 1973.
The method of measurement depended upon radioactivation of mercury with neutrons
and the subsequent quantification of characteristic gamma radiations after radiochemical
purification.
Mercury concentrations in seawater at several locations in the vicinity of 151°W,
71°N averaged 20 parts per trillion. The waters from all stations east of this location showed
a significantly smaller concentration. This difference may relate to penetration o f Bering-
Chukchi Sea water into the southern Beaufort Sea to 151°W. Marine sediments on the shelf
and slope between 143°W and 153°W contained about 100 parts per billion mercury, except
for those on the continental shelf between Barter Island and the Canning River, where the
concentration was less than half this value. These results are consistent with sediment input
from the respective rivers when their mercury content and mineralogy are considered. The
mercury content of river waters was 18 ppt and in reasonable agreement with the average of
snow samples (13 ppt). The burden of mercury in plankton was 37 ppb.This work was supported by the office of Naval Research under grant N R 083-290
Effective Compliance Means Imposing Individual Liability
Deputy Attorney General Sally Yates said it in a memo dated September 9, 2015, and her successor, Rod Rosenstein, said it in remarks dated October 6, 2017: corporations act through individuals, and compliance enforcement must necessarily account for holding individuals liable for the wrongs they orchestrate under cover of the corporate umbrella. The logic is reasonable and necessary. We blame corporations for catastrophic environmental events, misbranded drugs that cause injury, and financial products that destroy the life savings of those who have toiled for a living; yet at the helm of the corporations\u27guiding their path of impropriety\u27are people, many of whom who have benefited handsomely from the corporate misconduct that they have captained. Unfortunately, in comparison to the guilty pleas that are taken by corporations, which cannot be put behind bars, prosecutors\u27both criminal and civil\u27barely scratch the surface when it comes to pursuing the individual human culprits
Public-Private Litigation for Health
Public health litigation can be a powerful mechanism for addressing public health harms where alternative interventions have failed. It can draw public attention to corporate misconduct and create a public record of the actions taken and the harms done. In an ideal world, it could achieve compensation for past harms and incentivize deterrence of future misconduct. But the full public health potential of these lawsuits is rarely achieved, even when the suits are brought on behalf of federal, state, and local governments with the ostensible goal of protecting the health of the citizens. The increasing involvement of private attorneys in public litigation only adds to the challenges of using litigation to achieve public health goals.
While there are continuing debates over the desirability of litigation partnerships between state attorneys general (AGs) and private counsel, as a practical matter, the involvement of private law firms in public litigation is unlikely to disappear any time soon. This Article fills a critical gap in the literature on the privatization of public litigation by showing why, despite their shortcomings, arrangements between state and private lawyers have the potential to satisfy public health goals that might otherwise remain out of reach. It provides a theory of legal research and development to show why these arrangements are not only likely to persist but are also most likely to occur in high-impact public health litigation. This Article then examines how the incentives of both state AGs and private law firms influence choices along the litigation pathway in ways that may undermine the potential to achieve public health value. It concludes by proposing a novel impact-based approach to public-private litigation, providing a decision-making framework that AGs can adopt to increase the role of public health objectives in the litigation process
Methods for comprehensive experimental identification of RNA-protein interactions
The importance of RNA-protein interactions in controlling mRNA regulation and non-coding RNA function is increasingly appreciated. A variety of methods exist to comprehensively define RNA-protein interactions. We describe these methods and the considerations required for designing and interpreting these experiments
Generic Subsequence Matching Framework: Modularity, Flexibility, Efficiency
Subsequence matching has appeared to be an ideal approach for solving many
problems related to the fields of data mining and similarity retrieval. It has
been shown that almost any data class (audio, image, biometrics, signals) is or
can be represented by some kind of time series or string of symbols, which can
be seen as an input for various subsequence matching approaches. The variety of
data types, specific tasks and their partial or full solutions is so wide that
the choice, implementation and parametrization of a suitable solution for a
given task might be complicated and time-consuming; a possibly fruitful
combination of fragments from different research areas may not be obvious nor
easy to realize. The leading authors of this field also mention the
implementation bias that makes difficult a proper comparison of competing
approaches. Therefore we present a new generic Subsequence Matching Framework
(SMF) that tries to overcome the aforementioned problems by a uniform frame
that simplifies and speeds up the design, development and evaluation of
subsequence matching related systems. We identify several relatively separate
subtasks solved differently over the literature and SMF enables to combine them
in straightforward manner achieving new quality and efficiency. This framework
can be used in many application domains and its components can be reused
effectively. Its strictly modular architecture and openness enables also
involvement of efficient solutions from different fields, for instance
efficient metric-based indexes. This is an extended version of a paper
published on DEXA 2012.Comment: This is an extended version of a paper published on DEXA 201
Mixed messengers, unified message: spatial grouping from temporal structure
AbstractIn dynamic visual environments, objects can differ from their backgrounds in terms of their associated temporal structureâthe time course of changes in some stimulus property defining object and background. In a series of experiments, we investigated whether different âmessengersâ of temporal structure group into coherent spatial forms. Observers viewed arrays of Gabor patches in which different temporal structures designated figure and ground regions; extracting the figure required grouping across synchronized orientation, spatial frequency, phase, and/or contrast changes. Observers were able to extract spatial form from temporal structure even when information had to be combined across different messengers. Further, mixing messengers of temporal structure proved cost-free: task performance when grouping across messengers approximated performance when all information resided within a single messenger. Thus, the visual system can abstract temporal structure regardless of the messenger of the dynamic event; a coherent spatial structure emerges from this abstracted temporal structure
Shigella flexneri utilize the spectrin cytoskeleton during invasion and comet tail generation
<p>Abstract</p> <p>Background</p> <p>The spectrin cytoskeleton is emerging as an important host cell target of enteric bacterial pathogens. Recent studies have identified a crucial role for spectrin and its associated proteins during key pathogenic processes of <it>Listeria monocytogenes </it>and <it>Salmonella </it>Typhimurium infections. Here we investigate the involvement of spectrin cytoskeletal components during the pathogenesis of the invasive pathogen <it>Shigella flexneri.</it></p> <p>Results</p> <p>Immunofluorescent microscopy reveals that protein 4.1 (p4.1), but not adducin or spectrin, is robustly recruited to sites of <it>S. flexneri </it>membrane ruffling during epithelial cell invasion. Through siRNA-mediated knockdowns, we identify an important role for spectrin and the associated proteins adducin and p4.1 during <it>S. flexneri </it>invasion. Following internalization, all three proteins are recruited to the internalized bacteria, however upon generation of actin-rich comet tails, we observed spectrin recruitment to those structures in the absence of adducin or p4.1.</p> <p>Conclusion</p> <p>These findings highlight the importance of the spectrin cytoskeletal network during <it>S. flexneri </it>pathogenesis and further demonstrate that pathogenic events that were once thought to exclusively recruit the actin cytoskeletal system require additional cytoskeletal networks.</p
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