1,898 research outputs found
Chemical Mixture Methodology (CMM): Using 15 Health Code Numbers
The Chemical Mixture Methodology (CMM) is used for an emergency response and safety planning for chemical mixtures that cause irreversible or serious health effects. There are three major components of the CMM: Health Code Numbers (HCNs), the Hazard Index, and the Protective Action Criteria values. The HCNs are akin to medical diagnostic codes; they categorize the adverse health outcome that could be induced by exposure to an individual hazardous chemical. Currently, 60 HCNs are used in the CMM to characterize potential health effects for over 3,000 chemicals. Chemicals may have one or more HCNs; however, a maximum of 10 HCNs may be listed in the CMM dataset for each chemical. The HCNs for each chemical are ranked based on their seriousness and the impact of the health effect on a personâs ability to take protective action, with the most serious being included in the CMM. Many chemicals in the CMM dataset have 10 HCNs. This study explored how CMM results would vary if an additional five HCNs were allowed, if needed, for each chemical. A total of 361 common chemicals from the CMM dataset were updated to include up to five additional HCNs. To evaluate the 15-HCN approach, we used 127 test mixtures and each mixture was assessed using three different concentration distributions. This provided a total of 381 test cases in our assessment. Comparing results using the 15-HCN approach to those using the 10-HCN approach, showed no substantial difference in CMM results. This suggests that it may not be necessary to include more HCNs in the CMM dataset. The CMM team continues to update the CMM to support its many users in the United States and around the world. For further information on the CMM, visit http://orise.orau.gov/emi/scapa/chem-mixture-methodolgy/default.htm
A CLIMATOLOGICAL DIGEST FOR THE SUSQUEHANNA NUCLEAR POWER PLANT
This report is about the A Climatologist Digest for the Susquehanna Nuclear Power Plant. The authors have prepared preliminary statistical descripitions of the Meteorology at the sites of Susquehanna
Heartbeat of the Southern Oscillation explains ENSO climatic resonances
The El Ni~no-Southern Oscillation (ENSO) nonlinear oscillator phenomenon has a far reaching
influence on the climate and human activities. The up to 10 year quasi-period cycle of the El Ni~no and
subsequent La Ni~na is known to be dominated in the tropics by nonlinear physical interaction of wind with
the equatorial waveguide in the Pacific. Long-term cyclic phenomena do not feature in the current theory
of the ENSO process. We update the theory by assessing low (>10 years) and high (<10 years) frequency
coupling using evidence across tropical, extratropical, and Pacific basin scales. We analyze observations and
model simulations with a highly accurate method called Dominant Frequency State Analysis (DFSA) to
provide evidence of stable ENSO features. The observational data sets of the Southern Oscillation Index
(SOI), North Pacific Index Anomaly, and ENSO Sea Surface Temperature Anomaly, as well as a theoretical
model all confirm the existence of long-term and short-term climatic cycles of the ENSO process with
resonance frequencies of {2.5, 3.8, 5, 12â14, 61â75, 180} years. This fundamental result shows long-term and
short-term signal coupling with mode locking across the dominant ENSO dynamics. These dominant
oscillation frequency dynamics, defined as ENSO frequency states, contain a stable attractor with three
frequencies in resonance allowing us to coin the term Heartbeat of the Southern Oscillation due to its
characteristic shape. We predict future ENSO states based on a stable hysteresis scenario of short-term and
long-term ENSO oscillations over the next century
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A phase II study of temozolomide vs. procarbazine in patients with glioblastoma multiforme at first relapse.
A randomized, multicentre, open-label, phase II study compared temozolomide (TMZ), an oral second-generation alkylating agent, and procarbazine (PCB) in 225 patients with glioblastoma multiforme at first relapse. Primary objectives were to determine progression-free survival (PFS) at 6 months and safety for TMZ and PCB in adult patients who failed conventional treatment. Secondary objectives were to assess overall survival and health-related quality of life (HRQL). TMZ was given orally at 200 mg/m(2)/day or 150 mg/m(2)/day (prior chemotherapy) for 5 days, repeated every 28 days. PCB was given orally at 150 mg/m(2)/day or 125 mg/m(2)/day (prior chemotherapy) for 28 days, repeated every 56 days. HRQL was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30 [+3]) and the Brain Cancer Module 20 (BCM20). The 6-month PFS rate for patients who received TMZ was 21%, which met the protocol objective. The 6-month PFS rate for those who received PCB was 8% (P = 0.008, for the comparison). Overall PFS significantly improved with TMZ, with a median PFS of 12.4 weeks in the TMZ group and 8.32 weeks in the PCB group (P = 0.0063). The 6-month overall survival rate for TMZ patients was 60% vs. 44% for PCB patients (P = 0.019). Freedom from disease progression was associated with maintenance of HRQL, regardless of treatment received. TMZ had an acceptable safety profile; most adverse events were mild or moderate in severity
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Risk constraint measures developed for the outcome-based strategy for tank waste management
This report is one of a series of supporting documents for the outcome-based characterization strategy developed by PNNL. This report presents a set of proposed risk measures with risk constraint (acceptance) levels for use in the Value of Information process used in the NCS. The characterization strategy has developed a risk-based Value of Information (VOI) approach for comparing the cost-effectiveness of characterizing versus mitigating particular waste tanks or tank clusters. The preference between characterizing or mitigating in order to prevent an accident depends on the cost of those activities relative to the cost of the consequences of the accident. The consequences are defined as adverse impacts measured across a broad set of risk categories such as worker dose, public cancers, ecological harm, and sociocultural impacts. Within each risk measure, various {open_quotes}constraint levels{close_quotes} have been identified that reflect regulatory standards or conventionally negotiated thresholds of harm to Hanford resources and values. The cost of consequences includes the {open_quotes}costs{close_quote} of exceeding those constraint levels as well as a strictly linear costing per unit of impact within each of the risk measures. In actual application, VOI based-decision making is an iterative process, with a preliminary low-precision screen of potential technical options against the major risk constraints, followed by VOI analysis to determine the cost-effectiveness of gathering additional information and to select a preferred technical option, and finally a posterior screen to determine whether the preferred option meets all relevant risk constraints and acceptability criteria
The secret world of shrimps: polarisation vision at its best
Animal vision spans a great range of complexity, with systems evolving to
detect variations in optical intensity, distribution, colour, and polarisation.
Polarisation vision systems studied to date detect one to four channels of
linear polarisation, combining them in opponent pairs to provide
intensity-independent operation. Circular polarisation vision has never been
seen, and is widely believed to play no part in animal vision. Polarisation is
fully measured via Stokes' parameters--obtained by combined linear and circular
polarisation measurements. Optimal polarisation vision is the ability to see
Stokes' parameters: here we show that the crustacean \emph{Gonodactylus
smithii} measures the exact components required. This vision provides optimal
contrast-enhancement, and precise determination of polarisation with no
confusion-states or neutral-points--significant advantages. We emphasise that
linear and circular polarisation vision are not different modalities--both are
necessary for optimal polarisation vision, regardless of the presence of
strongly linear or circularly polarised features in the animal's environment.Comment: 10 pages, 6 figures, 2 table
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Hanford Site cleanup and transition: Risk data needs for decision making (Hanford risk data gap analysis decision guide)
Given the broad array of environmental problems, technical alternatives, and outcomes desired by different stakeholders at Hanford, DOE will have to make difficult resource allocations over the next few decades. Although some of these allocations will be driven purely by legal requirements, almost all of the major objectives of the cleanup and economic transition missions involve choices among alternative pathways. This study examined the following questions: what risk information is needed to make good decisions at Hanford; how do those data needs compare to the set(s) of risk data that will be generated by regulatory compliance activities and various non-compliance studies that are also concerned with risk? This analysis examined the Hanford Site missions, the Hanford Strategic Plan, known stakeholder values, and the most important decisions that have to be made at Hanford to determine a minimum domain of risk information required to make good decisions that will withstand legal, political, and technical scrutiny. The primary risk categories include (1) public health, (2) occupational health and safety, (3) ecological integrity, (4) cultural-religious welfare, and (5) socio-economic welfare
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