High probability neurotransmitter release sites represent an energy efficient design

PubMed Central

Lu, Zhongmin; Chouhan, Amit K.; Borycz, Jolanta A.; Lu, Zhiyuan; Rossano, Adam J; Brain, Keith L.; Zhou, You; Meinertzhagen, Ian A.; Macleod, Gregory T.

2016-01-01

Nerve terminals contain multiple sites specialized for the release of neurotransmitters. Release usually occurs with low probability, a design thought to confer many advantages. High probability release sites are not uncommon but their advantages are not well understood. Here we test the hypothesis that high probability release sites represent an energy efficient design. We examined release site probabilities and energy efficiency at the terminals of two glutamatergic motor neurons synapsing on the same muscle fiber in Drosophila larvae. Through electrophysiological and ultrastructural measurements we calculated release site probabilities to differ considerably between terminals (0.33 vs. 0.11). We estimated the energy required to release and recycle glutamate from the same measurements. The energy required to remove calcium and sodium ions subsequent to nerve excitation was estimated through microfluorimetric and morphological measurements. We calculated energy efficiency as the number of glutamate molecules released per ATP molecule hydrolyzed, and high probability release site terminals were found to be more efficient (0.13 vs. 0.06). Our analytical model indicates that energy efficiency is optimal (~0.15) at high release site probabilities (~0.76). As limitations in energy supply constrain neural function, high probability release sites might ameliorate such constraints by demanding less energy. Energy efficiency can be viewed as one aspect of nerve terminal function, in balance with others, because high efficiency terminals depress significantly during episodic bursts of activity. PMID:27593375

WHAT INNOVATIVE APPROACHES CAN BE DEVELOPED FOR MINING SITES?

EPA Science Inventory

Mining is essential to maintain our way of life. However, based upon industry's reporting in the most recent Toxic Release Inventory (TRI), the primary sources of heavy metal releases to the environment are mining and mining related activities. The hard rock mining industry rel...

Addendum to the Closure Report for Corrective Action Unit 322: Areas 1 & 3 Release Sites and Injection Wells Nevada Test Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynn Kidman

This document constitutes an addendum to the June 2006, Closure Report for Corrective Action Unit 322: Areas 1 & 3 Release Sites and Injection Wells as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, thismore » addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the URs for: • CAS 01-25-01, AST Release • CAS 03-25-03, Mud Plant AST Diesel Release These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove these URs because contamination is not present at these sites above the risk-based FALs. Requirements for inspecting and maintaining these URs will be canceled, and the postings and signage at each site will be removed. Fencing and posting may be present at these sites that are unrelated to the FFACO URs such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004f). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at these sites.« less

Measurement of Aerosolization of Asbestos from Soil Using the Releasable Asbestos Field Sampler (RAFS)

EPA Science Inventory

Releasable Asbestos Field Sampler (RAFS) was designed to provide an alternative to activity-based sampling (ABS) for determining likely asbestos exposure resulting from activities at site with low contaminant levels. This paper presents a description of the RAFS device and a comp...

F-actin-based Ca signaling-a critical comparison with the current concept of Ca signaling.

PubMed

Lange, Klaus; Gartzke, Joachim

2006-11-01

A short comparative survey on the current idea of Ca signaling and the alternative concept of F-actin-based Ca signaling is given. The two hypotheses differ in one central aspect, the mechanism of Ca storage. The current theory rests on the assumption of Ca-accumulating endoplasmic/sarcoplasmic reticulum-derived vesicles equipped with an ATP-dependent Ca pump and IP3- or ryanodine-sensitive channel-receptors for Ca-release. The alternative hypothesis proceeds from the idea of Ca storage at the high-affinity binding sites of actin filaments. Cellular sites of F-actin-based Ca storage are microvilli and the submembrane cytoskeleton. Several specific features of Ca signaling such as store-channel coupling, quantal Ca release, spiking and oscillations, biphasic and "phasic" uptake kinetics, and Ca-induced Ca release (CICR), which are not adequately described by the current concept, are inherent properties of the F-actin system and its dynamic state of treadmilling. Copyright 2006 Wiley-Liss, Inc.

Multi-kinetics and site-specific release of gabapentin and flurbiprofen from oral fixed-dose combination: in vitro release and in vivo food effect.

PubMed

Sonvico, Fabio; Conti, Chiara; Colombo, Gaia; Buttini, Francesca; Colombo, Paolo; Bettini, Ruggero; Barchielli, Marco; Leoni, Barbara; Loprete, Luca; Rossi, Alessandra

2017-09-28

In this work, a fixed-dose combination of gabapentin and flurbiprofen formulated as multilayer tablets has been designed, developed and studied in vitro and in vivo. The aim was to construct a single dosage form of the two drugs, able to perform a therapeutic program involving three release kinetics and two delivery sites, i.e., immediate release of gabapentin, intra-gastric prolonged release of gabapentin and intestinal (delayed) release of flurbiprofen. An oblong three-layer tablet was manufactured having as top layer a floating hydrophilic polymeric matrix for gastric release of gabapentin, as middle layer a disintegrating formulation for immediate release of a gabapentin loading dose and as bottom layer, an uncoated hydrophilic polymeric matrix, swellable but insoluble in gastric fluids, for delayed and prolonged release of flurbiprofen in intestinal environment. The formulations were studied in vitro and in vivo in healthy volunteers. The in vitro release rate assessment confirmed the programmed delivery design. A significant higher bioavailability of gabapentin administered 30min after meal, compared to fasting conditions or to dose administration 10min before meal, argued in favor of the gastro-retention of gabapentin prolonged release layer. The two drugs were delivered at different anatomical sites, since the food presence prolonged the gastric absorption of gabapentin from the floating layer and delayed the flurbiprofen absorption. The attainment of a successful delayed release of flurbiprofen was realized by a matrix based on a polymers' combination. The combined use of three hydrophilic polymers with different pH sensitivity provided the dosage form layer containing flurbiprofen with gastro-resistant characteristics without the use of film coating. Copyright © 2017 Elsevier B.V. All rights reserved.

A Markov State-based Quantitative Kinetic Model of Sodium Release from the Dopamine Transporter

NASA Astrophysics Data System (ADS)

Razavi, Asghar M.; Khelashvili, George; Weinstein, Harel

2017-01-01

The dopamine transporter (DAT) belongs to the neurotransmitter:sodium symporter (NSS) family of membrane proteins that are responsible for reuptake of neurotransmitters from the synaptic cleft to terminate a neuronal signal and enable subsequent neurotransmitter release from the presynaptic neuron. The release of one sodium ion from the crystallographically determined sodium binding site Na2 had been identified as an initial step in the transport cycle which prepares the transporter for substrate translocation by stabilizing an inward-open conformation. We have constructed Markov State Models (MSMs) from extensive molecular dynamics simulations of human DAT (hDAT) to explore the mechanism of this sodium release. Our results quantify the release process triggered by hydration of the Na2 site that occurs concomitantly with a conformational transition from an outward-facing to an inward-facing state of the transporter. The kinetics of the release process are computed from the MSM, and transition path theory is used to identify the most probable sodium release pathways. An intermediate state is discovered on the sodium release pathway, and the results reveal the importance of various modes of interaction of the N-terminus of hDAT in controlling the pathways of release.

Corrective Action Investigation Plan for Corrective Action Unit 104: Area 7 Yucca Flat Atmospheric Test Sites, Nevada National Security Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick Matthews

2011-08-01

CAU 104 comprises the 15 CASs listed below: (1) 07-23-03, Atmospheric Test Site T-7C; (2) 07-23-04, Atmospheric Test Site T7-1; (3) 07-23-05, Atmospheric Test Site; (4) 07-23-06, Atmospheric Test Site T7-5a; (5) 07-23-07, Atmospheric Test Site - Dog (T-S); (6) 07-23-08, Atmospheric Test Site - Baker (T-S); (7) 07-23-09, Atmospheric Test Site - Charlie (T-S); (8) 07-23-10, Atmospheric Test Site - Dixie; (9) 07-23-11, Atmospheric Test Site - Dixie; (10) 07-23-12, Atmospheric Test Site - Charlie (Bus); (11) 07-23-13, Atmospheric Test Site - Baker (Buster); (12) 07-23-14, Atmospheric Test Site - Ruth; (13) 07-23-15, Atmospheric Test Site T7-4; (14) 07-23-16,more » Atmospheric Test Site B7-b; (15) 07-23-17, Atmospheric Test Site - Climax These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viable CAAs that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the data quality objectives (DQOs) developed on April 28, 2011, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 104. The releases at CAU 104 consist of surface-deposited radionuclides from 30 atmospheric nuclear tests. The presence and nature of contamination at CAU 104 will be evaluated based on information collected from a field investigation. Radiological contamination will be evaluated based on a comparison of the total effective dose (TED) to the dose-based final action level (FAL). The presence of TED exceeding the FAL is considered a radiological contaminant of concern (COC). Anything identified as a COC will require corrective action. The TED will be calculated as the total of separate estimates of internal and external dose. Results from the analysis of soil samples will be used to calculate internal radiological dose. Thermoluminescent dosimeters will be used to measure external radiological dose. Based on process knowledge of the releases associated with the nuclear tests and radiological survey information about the location and shape of the resulting contamination plume, it was determined that the releases from the nuclear tests are co-located and will be investigated concurrently. A field investigation will be performed to define areas where TED exceeds the FAL and to determine whether other COCs are present at the site. The investigation will also collect information to determine the presence and nature of contamination associated with migration and excavation, as well as any potential releases discovered during the investigation. Appendix A provides a detailed discussion of the DQO methodology and the DQOs specific to each CAS.« less

Obsolete pesticide storage sites and their POP release into the environment--an Armenian case study.

PubMed

Dvorská, A; Sír, M; Honzajková, Z; Komprda, J; Cupr, P; Petrlík, J; Anakhasyan, E; Simonyan, L; Kubal, M

2012-07-01

Organochlorinated pesticides were widely applied in Armenia until the 1980s, like in all former Soviet Union republics. Subsequently, the problem of areas contaminated by organochlorinated pesticides emerged. Environmental, waste and food samples at one pesticide burial site (Nubarashen) and three former pesticide storage sites (Jrarat, Echmiadzin and Masis) were taken and analysed on the content of organochlorinated pesticides, polychlorinated dibenzo-p-dioxins and furans and dioxin-like polychlorinated biphenyls. Gradient sampling and diffusivity-based calculations provided information on the contamination release from the hot spots on a local scale. A risk analysis based on samples of locally produced food items characterised the impact of storage sites on the health of nearby residents. All four sites were found to be seriously contaminated. High pesticide levels and soil and air contamination gradients of several orders of magnitude were confirmed outside the fence of the Nubarashen burial site, confirming pesticide release. A storage in Jrarat, which was completely demolished in 1996 and contained numerous damaged bags with pure pesticides until 2011, was found to have polluted surrounding soils by wind dispersion of pesticide powders and air by significant evaporation of lindane and β-endosulfan during this period. Dichlorodiphenyltrichloroethane-contaminated eggs, sampled from hens roaming freely in the immediate surroundings of the Echmiadzin storage site, revealed a significant health risk for egg consumers above 1E-5. Although small in size and previously almost unknown to the public, storage sites like Echmiadzin, Masis and Jrarat were found to stock considerable amounts of obsolete pesticides and have a significant negative influence on the environment and human health. Multi-stakeholder cooperation proved to be successful in identifying such sites suspected to be significant sources of persistent organic pollutants.

Method for siting detectors within a facility

DOEpatents

Gleason, Nathaniel Jeremy Meyer

2007-12-11

A method, system and article of manufacture of siting one or more detectors in a facility represented with zones are provided. Signals S.sub.i,j representing an effect in zone j in response to a release of contaminant in zone i for one or more flow conditions are provided. A candidate architecture has one or more candidate zones. A limiting case signal is determined for each flow condition for multiple candidate architectures. The limiting case signal is a smallest system signal of multiple system signals associated with a release in a zone. Each system signal is a maximum one of the signals representing the effect in the candidate zones from the release in one zone for the flow condition. For each candidate architecture, a robust limiting case signal is determined based on a minimum of the limiting case signals. One candidate architecture is selected based on the robust limiting case signals.

Environmental Releases for Calendar Year 2001

DOE Office of Scientific and Technical Information (OSTI.GOV)

DYEKMAN, D L

2002-08-01

This report fulfills the annual reporting requirements of US Department of Energy (DOE) Order 5400.1, General Environmental Protection Program. The report contains tabular data summaries on air emissions and liquid effluents released to the environment as well as nonroutine releases during calendar year (CY) 2001. These releases, bearing radioactive and hazardous substances, were from Bechtel Hanford, Inc. (BHI), CH2M HILL Hanford Group, Inc. (CHG), and Fluor Hanford (FH) managed facilities and activities. These data were obtained from direct sampling and analysis and from estimates based upon approved release factors. This report further serves as a supplemental resource to the Hanfordmore » Site Environmental Report (HSER PNNL-13910), published by the Pacific Northwest National Laboratory. HSER includes a yearly accounting of the impacts on the surrounding populace and environment from major activities at the Hanford Site. HSER also summarizes the regulatory compliance status of the Hanford Site. Tables ES-1 through ES-5 display comprehensive data summaries of CY2001 air emission and liquid effluent releases. The data displayed in these tables compiles the following: Radionuclide air emissions; Nonradioactive air emissions; Radionuclides in liquid effluents discharged to ground; Total volumes and flow rates of radioactive liquid effluents discharged to ground; and Radionuclides discharged to the Columbia River.« less

Source Term Estimation of Radioxenon Released from the Fukushima Dai-ichi Nuclear Reactors Using Measured Air Concentrations and Atmospheric Transport Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eslinger, Paul W.; Biegalski, S.; Bowyer, Ted W.

2014-01-01

Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout from the Fukushima Daiichi nuclear accident in March 2011. Atmospheric transport modeling (ATM) of plumes of noble gases and particulates were performed soon after the accident to determine plausible detection locations of any radioactive releases to the atmosphere. We combine sampling data from multiple International Modeling System (IMS) locations in a new way to estimate the magnitude and time sequence of the releases. Dilution factors from the modeled plume at five different detection locations were combined with 57 atmospheric concentration measurements of 133-Xe taken from Marchmore » 18 to March 23 to estimate the source term. This approach estimates that 59% of the 1.24×1019 Bq of 133-Xe present in the reactors at the time of the earthquake was released to the atmosphere over a three day period. Source term estimates from combinations of detection sites have lower spread than estimates based on measurements at single detection sites. Sensitivity cases based on data from four or more detection locations bound the source term between 35% and 255% of available xenon inventory.« less

Technical bases and guidance for the use of composite soil sampling for demonstrating compliance with radiological release criteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vitkus, Timothy J.

2012-04-24

This guidance provides information on methodologies and the technical bases that licensees should consider for incorporating composite sampling strategies into final status survey (FSS) plans. In addition, this guidance also includes appropriate uses of composite sampling for generating the data for other decommissioning site investigations such as characterization or other preliminary site investigations.

Modeling avian exposures to perfluoroalkyl substances in aquatic habitats impacted by historical aqueous film forming foam releases.

PubMed

Larson, Emily S; Conder, Jason M; Arblaster, Jennifer A

2018-06-01

Releases of Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) associated with Aqueous Film Forming Foams (AFFFs) have the potential to impact on-site and downgradient aquatic habitats. Dietary exposures of aquatic-dependent birds were modeled for seven PFASs (PFHxA, PFOA, PFNA, PFDA, PFHxS, PFOS, and PFDS) using five different scenarios based on measurements of PFASs obtained from five investigations of sites historically-impacted by AFFF. Exposure modeling was conducted for four avian receptors representing various avian feeding guilds: lesser scaup (Aythya affinis), spotted sandpiper (Actitis macularia), great blue heron (Ardea herodias), and osprey (Pandion haliaetus). For the receptor predicted to receive the highest PFAS exposure (spotted sandpiper), model-predicted exposure to PFOS exceeded a laboratory-based, No Observed Adverse Effect Level exposure benchmark in three of the five model scenarios, confirming that risks to aquatic-dependent avian wildlife should be considered for investigations of historic AFFF releases. Perfluoroalkyl sulfonic acids (PFHxS, PFOS, and PFDS) represented 94% (on average) of total PFAS exposures due to their prevalence in historical AFFF formulations, and increased bioaccumulation in aquatic prey items and partitioning to aquatic sediment relative to perfluoroalkyl carboxylic acids. Sediment-associated PFASs (rather than water-associated PFASs) were the source of the highest predicted PFAS exposures, and are likely to be very important for understanding and managing AFFF site-specific ecological risks. Additional considerations for research needs and site-specific ecological risk assessments are discussed with the goal of optimizing ecological risk-based decision making at AFFF sites and prioritizing research needs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Do release-site biases reflect response to the Earth's magnetic field during position determination by homing pigeons?

PubMed

Mora, Cordula V; Walker, Michael M

2009-09-22

How homing pigeons (Columba livia) return to their loft from distant, unfamiliar sites has long been a mystery. At many release sites, untreated birds consistently vanish from view in a direction different from the home direction, a phenomenon called the release-site bias. These deviations in flight direction have been implicated in the position determination (or map) step of navigation because they may reflect local distortions in information about location that the birds obtain from the geophysical environment at the release site. Here, we performed a post hoc analysis of the relationship between vanishing bearings and local variations in magnetic intensity using previously published datasets for pigeons homing to lofts in Germany. Vanishing bearings of both experienced and naïve birds were strongly associated with magnetic intensity variations at release sites, with 90 per cent of bearings lying within +/-29 degrees of the magnetic intensity slope or contour direction. Our results (i) demonstrate that pigeons respond in an orderly manner to the local structure of the magnetic field at release sites, (ii) provide a mechanism for the occurrence of release-site biases and (iii) suggest that pigeons may derive spatial information from the magnetic field at the release site that could be used to estimate their current position relative to their loft.

A DNAzyme-mediated logic gate for programming molecular capture and release on DNA origami.

PubMed

Li, Feiran; Chen, Haorong; Pan, Jing; Cha, Tae-Gon; Medintz, Igor L; Choi, Jong Hyun

2016-06-28

Here we design a DNA origami-based site-specific molecular capture and release platform operated by a DNAzyme-mediated logic gate process. We show the programmability and versatility of this platform with small molecules, proteins, and nanoparticles, which may also be controlled by external light signals.

Landfill-stimulated iron reduction and arsenic release at the Coakley Superfund Site (NH).

PubMed

deLemos, Jamie L; Bostick, Benjamin C; Renshaw, Carl E; Stürup, Stefan; Feng, Xiahong

2006-01-01

Arsenic is a contaminant at more than one-third of all Superfund Sites in the United States. Frequently this contamination appearsto resultfrom geochemical processes rather than the presence of a well-defined arsenic source. Here we examine the geochemical processes that regulate arsenic levels at the Coakley Landfill Superfund Site (NH), a site contaminated with As, Cr, Pb, Ni, Zn, and aromatic hydrocarbons. Long-term field observations indicate that the concentrations of most of these contaminants have diminished as a result of treatment by monitored natural attenuation begun in 1998; however, dissolved arsenic levels increased modestly over the same interval. We attribute this increase to the reductive release of arsenic associated with poorly crystalline iron hydroxides within a glaciomarine clay layer within the overburden underlying the former landfill. Anaerobic batch incubations that stimulated iron reduction in the glaciomarine clay released appreciable dissolved arsenic and iron. Field observations also suggest that iron reduction associated with biodegradation of organic waste are partly responsible for arsenic release; over the five-year study period since a cap was emplaced to prevent water flow through the site, decreases in groundwater dissolved benzene concentrations at the landfill are correlated with increases in dissolved arsenic concentrations, consistent with the microbial decomposition of both benzene and other organics, and reduction of arsenic-bearing iron oxides. Treatment of contaminated groundwater increasingly is based on stimulating natural biogeochemical processes to degrade the contaminants. These results indicate that reducing environments created within organic contaminant plumes may release arsenic. In fact, the strong correlation (>80%) between elevated arsenic levels and organic contamination in groundwater systems at Superfund Sites across the United States suggests that arsenic contamination caused by natural degradation of organic contaminants may be widespread.

Behavioral profiles of the captive juvenile whooping crane (Grus americana) as an indicator of reintroduction behavior and survival

USGS Publications Warehouse

Kreger, M.D.

2003-01-01

Predation by bobcats (Lynx rufus) has been the greatest cause of mortality of whooping cranes (Grus americana) in the reintroduced population in Florida. This study investigated whether the behavior of juvenile cranes during captive rearing and shortly after release can be used to predict their chances of survival once released in the wild. This study also examined differences in behavior based on rearing treatments and whether differences observed during rearing continued at the release site. Experimental rearing treatments were parent reared (PR), hand reared (RR), and hand reared with exercise (HRE). Two annual cycles of cranes were observed from hatch to 20 weeks of age in captivity (n=56 birds). Post-release bebavioral data were collected at the release site for a minimum of two weeks (n=34 birds), with mortality data collected up to one year post release (n=38 birds). Behavioral time budgets were compared using repeated measures ANOVA. Logistic regression was used to build a model to identify behaviors that were associated with first-year survival. During rearing, PR birds were the most vigilant. There were no behavioral differences between HR and HRE birds. Generally, rearing treatments had few long-term effects on the post-release behavior of the birds. The main behavioral differences during rearing and after release were the frequency of bouts and the percentage of time spent performing different behaviors. This may be attributed to foraging strategies and adaptation from captive conditions to the wild. Survival was not related to rearing treatment. Fifty-five percent of the birds survived the first year post-release based upon data pooled over two years. During rearing, the frequency of foraging bouts was positively correlated to survival. Survival was negatively correlated to the frequency of walking bouts during rearing, and release weight of the birds. These correlations accounted for 32 percent of the variability in survival. At the release site, 20 percent of post-release survival was negatively correlated with the frequency of non vigilant bouts. This study suggests that none of the rearing treatments confer a survival advantage during the first year post release, however, survival may be improved by encouraging additional foraging opportunities during rearing.

Lessons Learned Using Fractions to Assess Risk at Petroleum Release Sites

DTIC Science & Technology

2004-04-01

Jet Fuel Bioavailability Hydrocarbon fractions Total Petroleum Hydrocarbons Weathered petroleum Sequestration 16. SECURITY CLASSIFICATION OF: 17...requirements at sites that were contaminated with petroleum products such as gasoline, diesel fuel , jet fuel , heating oil, lubricants and used motor oils...December 2002. Four of the demonstration sites were contaminated with jet fuel (i.e., JP-4, JP-5 or JP-8). The Misawa Air Base site was contaminated with

Addendum to the Closure Report for Corrective Action Unit 326: Areas 6 and 27 Release Sites, Nevada Test Site, Nevada, Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant Evenson

This document constitutes an addendum to the Closure Report for Corrective Action Unit 326: Areas 6 and 27 Release Sites, Nevada Test Site, Nevada (Revision 1), December 2002 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • Themore » cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the UR for CAS 06-25-01, CP-1 Heating Oil Release. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was reevaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the FFACO UR such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at this site.« less

Protein-Based Drug-Delivery Materials.

PubMed

Jao, Dave; Xue, Ye; Medina, Jethro; Hu, Xiao

2017-05-09

There is a pressing need for long-term, controlled drug release for sustained treatment of chronic or persistent medical conditions and diseases. Guided drug delivery is difficult because therapeutic compounds need to survive numerous transport barriers and binding targets throughout the body. Nanoscale protein-based polymers are increasingly used for drug and vaccine delivery to cross these biological barriers and through blood circulation to their molecular site of action. Protein-based polymers compared to synthetic polymers have the advantages of good biocompatibility, biodegradability, environmental sustainability, cost effectiveness and availability. This review addresses the sources of protein-based polymers, compares the similarity and differences, and highlights characteristic properties and functionality of these protein materials for sustained and controlled drug release. Targeted drug delivery using highly functional multicomponent protein composites to guide active drugs to the site of interest will also be discussed. A systematical elucidation of drug-delivery efficiency in the case of molecular weight, particle size, shape, morphology, and porosity of materials will then be demonstrated to achieve increased drug absorption. Finally, several important biomedical applications of protein-based materials with drug-delivery function-including bone healing, antibiotic release, wound healing, and corneal regeneration, as well as diabetes, neuroinflammation and cancer treatments-are summarized at the end of this review.

In Situ Oxalic Acid Injection to Accelerate Arsenic Remediation at a Superfund Site in New Jersey.

PubMed

Wovkulich, Karen; Stute, Martin; Mailloux, Brian J; Keimowitz, Alison R; Ross, James; Bostick, Benjamin; Sun, Jing; Chillrud, Steven N

2014-09-25

Arsenic is a prevalent contaminant at a large number of US Superfund sites; establishing techniques that accelerate As remediation could benefit many sites. Hundreds of tons of As were released into the environment by the Vineland Chemical Co. in southern New Jersey during its manufacturing lifetime (1949-1994), resulting in extensive contamination of surface and subsurface soils and sediments, groundwater, and the downstream watershed. Despite substantial intervention at this Superfund site, sufficient aquifer cleanup could require many decades if based on traditional pump and treat technologies only. Laboratory column experiments have suggested that oxalic acid addition to contaminated aquifer solids could promote significant As release from the solid phase. To evaluate the potential of chemical additions to increase As release in situ and boost treatment efficiency, a forced gradient pilot scale study was conducted on the Vineland site. During spring/summer 2009, oxalic acid and bromide tracer were injected into a small portion (~50 m 2 ) of the site for 3 months. Groundwater samples indicate that introduction of oxalic acid led to increased As release. Between 2.9 and 3.6 kg of As were removed from the sampled wells as a result of the oxalic acid treatment during the 3-month injection. A comparison of As concentrations on sediment cores collected before and after treatment and analyzed using X-ray fluorescence spectroscopy suggested reduction in As concentrations of ~36% (median difference) to 48% (mean difference). While further study is necessary, the addition of oxalic acid shows potential for accelerating treatment of a highly contaminated site and decreasing the As remediation time-scale.

Relations Between Residential Proximity to EPA-Designated Toxic Release Sites and Diffuse Large B-Cell Lymphoma Incidence.

PubMed

Bulka, Catherine; Nastoupil, Loretta J; Koff, Jean L; Bernal-Mizrachi, Leon; Ward, Kevin C; Williams, Jessica N; Bayakly, A Rana; Switchenko, Jeffrey M; Waller, Lance A; Flowers, Christopher R

2016-10-01

Examining the spatial patterns of diffuse large B-cell lymphoma (DLBCL) incidence and residential proximity to toxic release locations may provide insight regarding environmental and sociodemographic risk factors. We linked and geocoded cancer incidence data for the period 1999-2008 from the Georgia Comprehensive Cancer Registry with population data from the US Census and the Environmental Protection Agency's Toxics Release Inventory. We conducted cluster analyses and constructed Poisson regression models to assess DLBCL incidence as a function of mean distance to the toxic release sites. In total, 3851 incident DLBCL cases occurred among adults residing in Georgia between 1999 and 2008. Significant focal clustering was observed around 57% of ethylene oxide sites, 5% of benzene sites, 9% of tetrachloroethylene sites, 7% of styrene sites, 10% of formaldehyde sites, 5% of trichloroethylene sites, and 10% of all release sites. Mean distance to sites was significantly associated with DLBCL risk for all chemicals. Proximity to Toxics Release Inventory sites can be linked to increased DLBCL risk as assessed through focal clustering and Poisson regression, and confirmatory studies using geospatial mapping can aid in further specifying risk factors for DLBCL.

Architectural, Mechanical, Electrical, Plumbing, and Site Documents Associated with Sustainability Base, N232

NASA Technical Reports Server (NTRS)

Grymes, Rosalind A.; Martin, Rodney Alexander; Dianati, Soheila

2016-01-01

These files contain more precise and accurate representations of the architectural, mechanical, electrical, plumbing, and site information pertaining to Sustainability Base, aka Collaborative Support Facility, aka N232. These supersede the 'bid' drawings released in STI 8112 previously. They are useful for NASA researchers and collaborators in modeling the performance characteristics of the facility. Otherwise, they do not contain new data.

Shallow 3-D vertical seismic profiling around a contaminant withdrawal well on the Lawrence Livermore National Laboratory Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rector, J.; Bainer, R.; Milligan, P.

1997-01-30

One of the major problems associated with ground water contaminant remediation is well placement. Optimal-placement of wells requires an accurate knowledge of geologic structure and stratigraphy in the near surface sediments and rock (0 to 100 m). Without the development of remote imaging provided by geophysical techniques, the required spacing between treatment wells may be less than 2 m in order to be confident that all contaminant reservoirs had been remediated. One method for characterizing geologic structure and stratigraphy in the near surface is vertical seismic profiling (VSP), a technique often used on deep exploration wells to calibrate surface seismicmore » reflection data. For near-surface applications, VSP data can be acquired efficiently using an array of hydrophones lowered into a fluid-filled borehole (Milligan et al, 1997). In this paper we discuss the acquisition and processing of a 3-D VSP collected at a shallow remediation site located on the grounds of the Lawrence Livermore National Laboratory (LLNL) near Livermore, California. The site was used by the United States Navy as an air training base. At this time, initial releases of hazardous materials to the environment occurred in the form of solvents [volatile organic compounds (VOCs)] that were used for the cleaning of airplanes and their parts. Gasoline, diesel and other petroleum-based compounds are also known to have leaked into the ground. California Research and Development Company, a subsidy of Standard Oil, occupied the southeastern portion of the site from 1950 to 1954. The first releases of radioactive materials to the environment occurred at this time, with the beginning of testing of radioactive materials at the site. In 1952, LLNL acquired the site. Additional releases of VOCS, polychlorinated biphenyls (PCBs), metals, radionuclides (primarily tritium), gasoline and pesticides have occurred since. These releases were due to localized spills, landfills, surface impoundments, disposal pits, broken sewer lines and pipes, and leaking tanks.« less

Forest soil mineral weathering rates: use of multiple approaches

Treesearch

Randy K. Kolka; D.F. Grigal; E.A. Nater

1996-01-01

Knowledge of rates of release of base cations from mineral dissolution (weathering) is essential to understand ecosystem elemental cycling. Although much studied, rates remain enigmatic. We compared the results of four methods to determine cation (Ca + Mg + K) release rates at five forested soils/sites in the northcentral U.S.A. Our premise was that multiple...

Cathepsin B Cleavage of vcMMAE-Based Antibody-Drug Conjugate Is Not Drug Location or Monoclonal Antibody Carrier Specific.

PubMed

Gikanga, Benson; Adeniji, Nia S; Patapoff, Thomas W; Chih, Hung-Wei; Yi, Li

2016-04-20

Antibody-drug conjugates (ADCs) require thorough characterization and understanding of product quality attributes. The framework of many ADCs comprises one molecule of antibody that is usually conjugated with multiple drug molecules at various locations. It is unknown whether the drug release rate from the ADC is dependent on drug location, and/or local environment, dictated by the sequence and structure of the antibody carrier. This study addresses these issues with valine-citrulline-monomethylauristatin E (vc-MMAE)-based ADC molecules conjugated at reduced disulfide bonds, by evaluating the cathepsin B catalyzed drug release rate of ADC molecules with different drug distributions or antibody carriers. MMAE drug release rates at different locations on ADC I were compared to evaluate the impact of drug location. No difference in rates was observed for drug released from the V(H), V(L), or C(H)2 domains of ADC I. Furthermore, four vc-MMAE ADC molecules were chosen as substrates for cathepsin B for evaluation of Michaelis-Menten parameters. There was no significant difference in K(M) or k(cat) values, suggesting that different sequences of the antibody carrier do not result in different drug release rates. Comparison between ADCs and small molecules containing vc-MMAE moieties as substrates for cathepsin B suggests that the presence of IgG1 antibody carrier, regardless of its bulkiness, does not impact drug release rate. Finally, a molecular dynamics simulation on ADC II revealed that the val-cit moiety at each of the eight possible conjugation sites was, on average, solvent accessible over 50% of its maximum solvent accessible surface area (SASA) during a 500 ns trajectory. Combined, these results suggest that the cathepsin cleavage sites for conjugated drugs are exposed enough for the enzyme to access and that the drug release rate is rather independent of drug location or monoclonal antibody carrier. Therefore, the distribution of drug conjugation at different sites is not a critical parameter to control in manufacturing of the vc-MMAE-based ADC conjugated at reduced disulfide bonds.

Containment wells to form hydraulic barriers along site boundaries.

PubMed

Vo, D; Ramamurthy, A S; Qu, J; Zhao, X P

2008-12-15

In the field, aquifer remediation methods include pump and treat procedures based on hydraulic control systems. They are used to reduce the level of residual contamination present in the soil and soil pores of aquifers. Often, physical barriers are erected along the boundaries of the target (aquifer) site to reduce the leakage of the released soil contaminant to the surrounding regions. Physical barriers are expensive to build and dismantle. Alternatively, based on simple hydraulic principles, containment wells or image wells injecting clear water can be designed and built to provide hydraulic barriers along the contaminated site boundaries. For brevity, only one pattern of containment well system that is very effective is presented in detail. The study briefly reports about the method of erecting a hydraulic barrier around a contaminated region based on the simple hydraulic principle of images. During the clean-up period, hydraulic barriers can considerably reduce the leakage of the released contaminant from the target site to surrounding pristine regions. Containment wells facilitate the formation of hydraulic barriers. Hence, they control the movement of contaminants away from the site that is being remedied. However, these wells come into play, only when the pumping operation for cleaning up the site is active. After operation, they can be filled with soil to permit the natural ground water movement. They can also be used as monitoring wells.

10 CFR 50.83 - Release of part of a power reactor facility or site for unrestricted use.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Release of part of a power reactor facility or site for... of a power reactor facility or site for unrestricted use. (a) Prior written NRC approval is required... release. Nuclear power reactor licensees seeking NRC approval shall— (1) Evaluate the effect of releasing...

10 CFR 50.83 - Release of part of a power reactor facility or site for unrestricted use.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Release of part of a power reactor facility or site for... of a power reactor facility or site for unrestricted use. (a) Prior written NRC approval is required... release. Nuclear power reactor licensees seeking NRC approval shall— (1) Evaluate the effect of releasing...

In Situ Oxalic Acid Injection to Accelerate Arsenic Remediation at a Superfund Site in New Jersey

PubMed Central

Wovkulich, Karen; Stute, Martin; Mailloux, Brian J.; Keimowitz, Alison R.; Ross, James; Bostick, Benjamin; Sun, Jing; Chillrud, Steven N.

2015-01-01

Arsenic is a prevalent contaminant at a large number of US Superfund sites; establishing techniques that accelerate As remediation could benefit many sites. Hundreds of tons of As were released into the environment by the Vineland Chemical Co. in southern New Jersey during its manufacturing lifetime (1949–1994), resulting in extensive contamination of surface and subsurface soils and sediments, groundwater, and the downstream watershed. Despite substantial intervention at this Superfund site, sufficient aquifer cleanup could require many decades if based on traditional pump and treat technologies only. Laboratory column experiments have suggested that oxalic acid addition to contaminated aquifer solids could promote significant As release from the solid phase. To evaluate the potential of chemical additions to increase As release in situ and boost treatment efficiency, a forced gradient pilot scale study was conducted on the Vineland site. During spring/summer 2009, oxalic acid and bromide tracer were injected into a small portion (~50 m2) of the site for 3 months. Groundwater samples indicate that introduction of oxalic acid led to increased As release. Between 2.9 and 3.6 kg of As were removed from the sampled wells as a result of the oxalic acid treatment during the 3-month injection. A comparison of As concentrations on sediment cores collected before and after treatment and analyzed using X-ray fluorescence spectroscopy suggested reduction in As concentrations of ~36% (median difference) to 48% (mean difference). While further study is necessary, the addition of oxalic acid shows potential for accelerating treatment of a highly contaminated site and decreasing the As remediation time-scale. PMID:25598701

Changes in plant communities after planting and release of conifer seedlings: Early findings

Treesearch

Philip M. McDonald; Gary O. Fiddler

2001-01-01

Plant diversity, density, and development data from an extensive research program in conifer plantations in northern California suggest changes in plant community composition after site preparation and many kinds of release. Based on 17 studies, the average number of species per study area after 10 years was 25 with composition of 1 conifer, 1 hardwood, 8 shrubs, 12...

Effects of multiple founder populations on spatial genetic structure of reintroduced American martens.

PubMed

Williams, Bronwyn W; Scribner, Kim T

2010-01-01

Reintroductions and translocations are increasingly used to repatriate or increase probabilities of persistence for animal and plant species. Genetic and demographic characteristics of founding individuals and suitability of habitat at release sites are commonly believed to affect the success of these conservation programs. Genetic divergence among multiple source populations of American martens (Martes americana) and well documented introduction histories permitted analyses of post-introduction dispersion from release sites and development of genetic clusters in the Upper Peninsula (UP) of Michigan <50 years following release. Location and size of spatial genetic clusters and measures of individual-based autocorrelation were inferred using 11 microsatellite loci. We identified three genetic clusters in geographic proximity to original release locations. Estimated distances of effective gene flow based on spatial autocorrelation varied greatly among genetic clusters (30-90 km). Spatial contiguity of genetic clusters has been largely maintained with evidence for admixture primarily in localized regions, suggesting recent contact or locally retarded rates of gene flow. Data provide guidance for future studies of the effects of permeabilities of different land-cover and land-use features to dispersal and of other biotic and environmental factors that may contribute to the colonization process and development of spatial genetic associations.

Radiocesium in the Savannah River Site environment.

PubMed

Carlton, W H; Murphy, C E; Evans, A G

1994-09-01

The Savannah River Site has produced plutonium, tritium, and other special nuclear materials for national defense, other government programs, and some civilian purposes. Radiocesium, a waste product, has been released to the environment during the operation of five reactors, two radio-chemical processing facilities, and a high-level waste storage system. During the period 1955-1989, 130 GBq of 137Cs was released to the atmosphere and 2.2 x 10(4) GBq was released to site streams and ponds. Approximately 65% of the latter remained on the site. The maximum individual effective dose equivalent at the site boundary was estimated to be 3.3 microSv from atmospheric releases and 600 microSv from liquid releases. The 80-km population dose was 1.6 person-Sv.

Consequence assessment for Airborne Releases of SO{sub 2} from the Y-12 Pilot Dechlorination Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pendergrass, W.R.

The Atmospheric Turbulence and Diffusion Division was requested by the Department of Energy`s Oak Ridge Operations Office to conduct a consequence assessment for potential atmospheric releases of SO{sub 2} from the Y-12 Pilot Dechlorination Facility. The focus of the assessment was to identify ``worst`` case meteorology which posed the highest concentration exposure potential for both on-site as well as off-site populations. A series of plausible SO{sub 2} release scenarios were provided by Y-12 for the consequence assessment. Each scenario was evaluated for predictions of downwind concentration, estimates of a five-minute time weighted average, and estimate of the dimension of themore » puff. The highest hazard potential was associated with Scenario 1, in which a total of eight SO{sub 2} cylinders are released internally to the Pilot Facility and exhausted through the emergency venting system. A companion effort was also conducted to evaluate the potential for impact of releases of SO{sub 2} from the Pilot Facility on the population of Oak Ridge. While specific transport trajectory data is not available for the Pilot Facility, extrapolations based on the Oak Ridge Site Survey and climatological records from the Y-12 meteorological program does not indicate the potential for impact on the city of Oak Ridge. Steering by the local topographical features severely limits the potential impact ares. Due to the lack of specific observational data, both tracer and meteorological, only inferences can be made concerning impact zones. It is recommended tat the Department of Energy Oak Ridge Operations examine the potential for off-site impact and develop the background data to prepare impact zones for releases of hazardous materials from the Y-12 facility.« less

Preparation of ionic-crosslinked chitosan-based gel beads and effect of reaction conditions on drug release behaviors.

PubMed

Chen, Shilan; Liu, Mingzhu; Jin, Shuping; Wang, Bin

2008-02-12

Drug-loaded chitosan (CS) beads were prepared under simple and mild condition using trisodium citrate as ionic crosslinker. The beads were further coated with poly(methacrylic acid) (PMAA) by dipping the beads in PMAA aqueous solution. The surface and cross-section morphology of these beads were observed by scanning electron microscopy and the observation showed that the coating beads had core-shell structure. In vitro release of model drug from these beads obtained under different reaction conditions was investigated in buffer medium (pH 1.8). The results showed that the rapid drug release was restrained by PMAA coating and the optimum conditions for preparing CS-based drug-loaded beads were decided through the effect of reaction conditions on the drug release behaviors. In addition, the drug release mechanism of CS-based drug-loaded beads was analyzed by Peppa's potential equation. According to this study, the ionic-crosslinked CS beads coated by PMAA could serve as suitable candidate for drug site-specific carrier in stomach.

Controlled release of metronidazole from composite poly-ε-caprolactone/alginate (PCL/alginate) rings for dental implants.

PubMed

Lan, Shih-Feng; Kehinde, Timilehin; Zhang, Xiangming; Khajotia, Sharukh; Schmidtke, David W; Starly, Binil

2013-06-01

Dental implants provide support for dental crowns and bridges by serving as abutments for the replacement of missing teeth. To prevent bacterial accumulation and growth at the site of implantation, solutions such as systemic antibiotics and localized delivery of bactericidal agents are often employed. The objective of this study was to demonstrate a novel method of controlled localized delivery of antibacterial agents to an implant site using a biodegradable custom fabricated ring. The study involved incorporating a model antibacterial agent (metronidazole) into custom designed poly-ε-caprolactone/alginate (PCL/alginate) composite rings to produce the intended controlled release profile. The rings can be designed to fit around the body of any root form dental implants of various diameters, shapes and sizes. In vitro release studies indicate that pure (100%) alginate rings exhibited an expected burst release of metronidazole in the first few hours, whereas Alginate/PCL composite rings produced a medium burst release followed by a sustained release for a period greater than 4 weeks. By varying the PCL/alginate weight ratios, we have shown that we can control the amount of antibacterial agents released to provide the minimal inhibitory concentration (MIC) needed for adequate protection. The fabricated composite rings have achieved a 50% antibacterial agent release profile over the first 48 h and the remaining amount slowly released over the remainder of the study period. The PCL/alginate agent release characteristic fits the Ritger-Peppas model indicating a diffusion-based mechanism during the 30-day study period. The developed system demonstrates a controllable drug release profile and the potential for the ring to inhibit bacterial biofilm growth for the prevention of diseases such as peri-implantitis resulting from bacterial infection at the implant site. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Protein-Based Drug-Delivery Materials

PubMed Central

Jao, Dave; Xue, Ye; Medina, Jethro; Hu, Xiao

2017-01-01

There is a pressing need for long-term, controlled drug release for sustained treatment of chronic or persistent medical conditions and diseases. Guided drug delivery is difficult because therapeutic compounds need to survive numerous transport barriers and binding targets throughout the body. Nanoscale protein-based polymers are increasingly used for drug and vaccine delivery to cross these biological barriers and through blood circulation to their molecular site of action. Protein-based polymers compared to synthetic polymers have the advantages of good biocompatibility, biodegradability, environmental sustainability, cost effectiveness and availability. This review addresses the sources of protein-based polymers, compares the similarity and differences, and highlights characteristic properties and functionality of these protein materials for sustained and controlled drug release. Targeted drug delivery using highly functional multicomponent protein composites to guide active drugs to the site of interest will also be discussed. A systematical elucidation of drug-delivery efficiency in the case of molecular weight, particle size, shape, morphology, and porosity of materials will then be demonstrated to achieve increased drug absorption. Finally, several important biomedical applications of protein-based materials with drug-delivery function—including bone healing, antibiotic release, wound healing, and corneal regeneration, as well as diabetes, neuroinflammation and cancer treatments—are summarized at the end of this review. PMID:28772877

Life cycle of petroleum biodegradation metabolite plumes, and implications for risk management at fuel release sites.

PubMed

Zemo, Dawn A; O'Reilly, Kirk T; Mohler, Rachel E; Magaw, Renae I; Espino Devine, Catalina; Ahn, Sungwoo; Tiwary, Asheesh K

2017-07-01

This paper summarizes the results of a 5-y research study of the nature and toxicity of petroleum biodegradation metabolites in groundwater at fuel release sites that are quantified as diesel-range "Total Petroleum Hydrocarbons" (TPH; also known as TPHd, diesel-range organics (DRO), etc.), unless a silica gel cleanup (SGC) step is used on the sample extract prior to the TPH analysis. This issue is important for site risk management in regulatory jurisdictions that use TPH as a metric; the presence of these metabolites may preclude site closure even if all other factors can be considered "low-risk." Previous work has shown that up to 100% of the extractable organics in groundwater at petroleum release sites can be biodegradation metabolites. The metabolites can be separated from the hydrocarbons by incorporating an SGC step; however, regulatory agency acceptance of SGC has been inconsistent because of questions about the nature and toxicity of the metabolites. The present study was conducted to answer these specific questions. Groundwater samples collected from source and downgradient wells at fuel release sites were extracted and subjected to targeted gas chromatography-mass spectrometry (GC-MS) and nontargeted two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-MS) analyses, and the metabolites identified in each sample were classified according to molecular structural classes and assigned an oral reference dose (RfD)-based toxicity ranking. Our work demonstrates that the metabolites identified in groundwater at biodegrading fuel release sites are in classes ranked as low toxicity to humans and are not expected to pose significant risk to human health. The identified metabolites naturally attenuate in a predictable manner, with an overall trend to an increasingly higher proportion of organic acids and esters, and a lower human toxicity profile, and a life cycle that is consistent with the low-risk natural attenuation paradigm adopted by many regulatory agencies for petroleum release sites. Integr Environ Assess Manag 2017;13:714-727. © 2016 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2016 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Mechanisms of strand break formation in DNA due to the direct effect of ionizing radiation: the dependency of free base release on the length of alternating CG oligodeoxynucleotides.

PubMed

Sharma, Kiran K; Razskazovskiy, Yuriy; Purkayastha, Shubhadeep; Bernhard, William A

2009-06-11

The question of how NA base sequence influences the yield of DNA strand breaks produced by the direct effect of ionizing radiation was investigated in a series of oligodeoxynucleotides of the form (d(CG)(n))(2) and (d(GC)(n))(2). The yields of free base release from X-irradiated DNA films containing 2.5 waters/nucleotide were measured by HPLC as a function of oligomer length. For (d(CG)(n))(2), the ratio of the Gua yield to Cyt yield, R, was relatively constant at 2.4-2.5 for n = 2-4 and it decreased to 1.2 as n increased from 5 to 10. When Gua was moved to the 5' end, for example going from d(CG)(5) to d(GC)(5), R dropped from 1.9 +/- 0.1 to 1.1 +/- 0.1. These effects are poorly described if the chemistry at the oligomer ends is assumed to be independent of the remainder of the oligomer. A mathematical model incorporating charge transfer through the base stack was derived to explain these effects. In addition, EPR was used to measure the yield of trapped-deoxyribose radicals at 4 K following X-irradiation at 4 K. The yield of free base release was substantially greater, by 50-100 nmol/J, than the yield of trapped-deoxyribose radicals. Therefore, a large fraction of free base release stems from a nonradical intermediate. For this intermediate, a deoxyribose carbocation formed by two one-electron oxidations is proposed. This reaction pathway requires that the hole (electron loss site) transfers through the base stack and, upon encountering a deoxyribose hole, oxidizes that site to form a deoxyribose carbocation. This reaction mechanism provides a consistent way of explaining both the absence of trapped radical intermediates and the unusual dependence of free base release on oligomer length.

Errors in the estimation of the variance: implications for multiple-probability fluctuation analysis.

PubMed

Saviane, Chiara; Silver, R Angus

2006-06-15

Synapses play a crucial role in information processing in the brain. Amplitude fluctuations of synaptic responses can be used to extract information about the mechanisms underlying synaptic transmission and its modulation. In particular, multiple-probability fluctuation analysis can be used to estimate the number of functional release sites, the mean probability of release and the amplitude of the mean quantal response from fits of the relationship between the variance and mean amplitude of postsynaptic responses, recorded at different probabilities. To determine these quantal parameters, calculate their uncertainties and the goodness-of-fit of the model, it is important to weight the contribution of each data point in the fitting procedure. We therefore investigated the errors associated with measuring the variance by determining the best estimators of the variance of the variance and have used simulations of synaptic transmission to test their accuracy and reliability under different experimental conditions. For central synapses, which generally have a low number of release sites, the amplitude distribution of synaptic responses is not normal, thus the use of a theoretical variance of the variance based on the normal assumption is not a good approximation. However, appropriate estimators can be derived for the population and for limited sample sizes using a more general expression that involves higher moments and introducing unbiased estimators based on the h-statistics. Our results are likely to be relevant for various applications of fluctuation analysis when few channels or release sites are present.

Light Control of Insulin Release and Blood Glucose Using an Injectable Photoactivated Depot.

PubMed

Sarode, Bhagyesh R; Kover, Karen; Tong, Pei Y; Zhang, Chaoying; Friedman, Simon H

2016-11-07

In this work we demonstrate that blood glucose can be controlled remotely through light stimulated release of insulin from an injected cutaneous depot. Human insulin was tethered to an insoluble but injectable polymer via a linker, which was based on the light cleavable di-methoxy nitrophenyl ethyl (DMNPE) group. This material was injected into the skin of streptozotocin-treated diabetic rats. We observed insulin being released into the bloodstream after a 2 min trans-cutaneous irradiation of this site by a compact LED light source. Control animals treated with the same material, but in which light was blocked from the site, showed no release of insulin into the bloodstream. We also demonstrate that additional pulses of light from the light source result in additional pulses of insulin being absorbed into circulation. A significant reduction in blood glucose was then observed. Together, these results demonstrate the feasibility of using light to allow for the continuously variable control of insulin release. This in turn has the potential to allow for the tight control of blood glucose without the invasiveness of insulin pumps and cannulas.

Signal mass and Ca²⁺ kinetics in local calcium events: a modeling study.

PubMed

Baran, Irina; Ganea, Constanta; Ungureanu, Raluca; Tofolean, Ioana Teodora

2012-02-01

We use a detailed modeling formalism based on numerical simulations of local calcium release events where the blurring of the image, the presence of diffusional barriers provided by large organelles situated close to the release site, as well as the variable position of the scan line with respect to the release site are taken into consideration. We have investigated the effect of the fluorescence noise fluctuations on the accuracy in computing the signal mass from linescan recordings and obtained a quantitative description of both the signal mass and the local increase in the free Ca(2+) level as a function of the release current, the release duration and the orientation of the scan line, for three different levels of noise magnitudes. The model could provide a very good fit to a wide set of available experimental data regarding the signal mass of puffs visualized by fluorescence microscopy in the Xenopus oocyte loaded with 40 μM Oregon Green-1 in the absence of the calcium chelator EGTA. Numerical simulations also predict the amplitude and the kinetics of calcium signals evolving in the absence of the indicator, and indicate that sub-maximal activation of IP(3) receptors could produce in average levels of about 2 μM and 0.4 μM free Ca(2+) close to a release site located in the animal or in the vegetal hemisphere, respectively, whereas the maximal levels reached in more rare events could be 11 μM and 4 μM, respectively.

Atmospheric Dispersion Modeling of the February 2014 Waste Isolation Pilot Plant Release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nasstrom, John; Piggott, Tom; Simpson, Matthew

2015-07-22

This report presents the results of a simulation of the atmospheric dispersion and deposition of radioactivity released from the Waste Isolation Pilot Plant (WIPP) site in New Mexico in February 2014. These simulations were made by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL), and supersede NARAC simulation results published in a previous WIPP report (WIPP, 2014). The results presented in this report use additional, more detailed data from WIPP on the specific radionuclides released, radioactivity release amounts and release times. Compared to the previous NARAC simulations, the new simulation results in this report aremore » based on more detailed modeling of the winds, turbulence, and particle dry deposition. In addition, the initial plume rise from the exhaust vent was considered in the new simulations, but not in the previous NARAC simulations. The new model results show some small differences compared to previous results, but do not change the conclusions in the WIPP (2014) report. Presented are the data and assumptions used in these model simulations, as well as the model-predicted dose and deposition on and near the WIPP site. A comparison of predicted and measured radionuclide-specific air concentrations is also presented.« less

77 FR 56273 - Conflict Minerals

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-12

....gov/comments/s7-40-10/s74010.shtml (``Post-Proposing Release Web site''). Many commentators provided comments on both the pre- and post-Proposing Release Web sites. Generally, our references to comment letters refer to the comments on the post-Proposing Release Web site. When we refer to a comment letter...

GZ-793A, a lobelane analog, interacts with the vesicular monoamine transporter-2 to inhibit the effect of methamphetamine

PubMed Central

Horton, David B.; Nickell, Justin R.; Zheng, Guangrong; Crooks, Peter A.; Dwoskin, Linda P.

2013-01-01

GZ-793A inhibits methamphetamine-evoked dopamine release from striatal slices and methamphetamine self-administration in rats. GZ-793A potently and selectively inhibits dopamine uptake at the vesicular monoamine transporter-2 (VMAT2). The present study determined GZ-793A’s ability to evoke [3H]dopamine release and inhibit methamphetamine-evoked [3H]dopamine release from isolated striatal synaptic vesicles. Results show GZ-793A concentration-dependent [3H]dopamine release; nonlinear regression revealed a two-site model of interaction with VMAT2 (High- and Low-EC50 = 15.5 nM and 29.3 µM, respectively). Tetrabenazine and reserpine completely inhibited the GZ-793A-evoked [3H]dopamine release, however, only at the High-affinity site. Low concentrations of GZ-793A that interact with the extravesicular dopamine uptake site and the High-affinity intravesicular DA release site also inhibited methamphetamine-evoked [3H]dopamine release from synaptic vesicles. A rightward shift in the methamphetamine concentration-response was evident with increasing concentrations of GZ-793A, and the Schild regression slope was 0.49±0.08, consistent with surmountable allosteric inhibition. These results support a hypothetical model of GZ-793A interaction at more than one site on VMAT2 protein, which explains its potent inhibition of dopamine uptake, dopamine release via a High-affinity tetrabenazine- and reserpine-sensitive site, dopamine release via a Low-affinity tetrabenazine- and reserpine-insensitive site, and low-affinity interaction with the dihydrotetrabenazine binding site on VMAT2. GZ-793A-inhibition of the effects of methamphetamine supports its potential as a therapeutic agent for the treatment of methamphetamine abuse. PMID:23875622

Insight into the Structural Determinants of Imidazole Scaffold-Based Derivatives as TNF-α Release Inhibitors by in Silico Explorations

PubMed Central

Wang, Yuan; Wu, Mingwei; Ai, Chunzhi; Wang, Yonghua

2015-01-01

Presently, 151 widely-diverse pyridinylimidazole-based compounds that show inhibitory activities at the TNF-α release were investigated. By using the distance comparison technique (DISCOtech), comparative molecular field analysis (CoMFA), and comparative molecular similarity index analysis (CoMSIA) methods, the pharmacophore models and the three-dimensional quantitative structure-activity relationships (3D-QSAR) of the compounds were explored. The proposed pharmacophore model, including two hydrophobic sites, two aromatic centers, two H-bond donor atoms, two H-bond acceptor atoms, and two H-bond donor sites characterizes the necessary structural features of TNF-α release inhibitors. Both the resultant CoMFA and CoMSIA models exhibited satisfactory predictability (with Q2 (cross-validated correlation coefficient) = 0.557, R2ncv (non-cross-validated correlation coefficient) = 0.740, R2pre (predicted correlation coefficient) = 0.749 and Q2 = 0.598, R2ncv = 0.767, R2pre = 0.860, respectively). Good consistency was observed between the 3D-QSAR models and the pharmacophore model that the hydrophobic interaction and hydrogen bonds play crucial roles in the mechanism of actions. The corresponding contour maps generated by these models provide more diverse information about the key intermolecular interactions of inhibitors with the surrounding environment. All these models have extended the understanding of imidazole-based compounds in the structure-activity relationship, and are useful for rational design and screening of novel 2-thioimidazole-based TNF-α release inhibitors. PMID:26307982

Insight into the Structural Determinants of Imidazole Scaffold-Based Derivatives as TNF-α Release Inhibitors by in Silico Explorations.

PubMed

Wang, Yuan; Wu, Mingwei; Ai, Chunzhi; Wang, Yonghua

2015-08-25

Presently, 151 widely-diverse pyridinylimidazole-based compounds that show inhibitory activities at the TNF-α release were investigated. By using the distance comparison technique (DISCOtech), comparative molecular field analysis (CoMFA), and comparative molecular similarity index analysis (CoMSIA) methods, the pharmacophore models and the three-dimensional quantitative structure-activity relationships (3D-QSAR) of the compounds were explored. The proposed pharmacophore model, including two hydrophobic sites, two aromatic centers, two H-bond donor atoms, two H-bond acceptor atoms, and two H-bond donor sites characterizes the necessary structural features of TNF-α release inhibitors. Both the resultant CoMFA and CoMSIA models exhibited satisfactory predictability (with Q(2) (cross-validated correlation coefficient) = 0.557, R(2)ncv (non-cross-validated correlation coefficient) = 0.740, R(2)pre (predicted correlation coefficient) = 0.749 and Q(2) = 0.598, R(2)ncv = 0.767, R(2)pre = 0.860, respectively). Good consistency was observed between the 3D-QSAR models and the pharmacophore model that the hydrophobic interaction and hydrogen bonds play crucial roles in the mechanism of actions. The corresponding contour maps generated by these models provide more diverse information about the key intermolecular interactions of inhibitors with the surrounding environment. All these models have extended the understanding of imidazole-based compounds in the structure-activity relationship, and are useful for rational design and screening of novel 2-thioimidazole-based TNF-α release inhibitors.

TEMPORAL TRENDS OF AROCLOR 1268 IN THE TAUNTON RIVER ESTUARY: EVIDENCE OF EARLY PRODUCTION, USE AND RELEASE TO THE ENVIRONMENT

EPA Science Inventory

Sediment cores were collected at three sites from the Lower Taunton River in Narragansett Bay, MA, dated and examined for PCBs. At each site, PCBs first appear in the sediment cores at depths corresponding to 1929 based on a combination of radiometric and anthropogenic dating pr...

Economics of site preparation and release treatments using herbicides in Central Georgia

Treesearch

Rodney L. Busby; James H. Miller; M. Boyd Edwards

1998-01-01

Abstract. Land expectation values (LEV) of site preparation and release treatments using herbicides in central Georgia are calculated and compared Loblolly pine growth and hardwood competition levels were measured at age 6 for the site preparation treatments and age 8 for the release treatments. These measurements were projected to final harvest...

Thiol–ene click hydrogels for therapeutic delivery

PubMed Central

Kharkar, Prathamesh M.; Rehmann, Matthew S.; Skeens, Kelsi M.; Maverakis, Emanual; Kloxin, April M.

2016-01-01

Hydrogels are of growing interest for the delivery of therapeutics to specific sites in the body. For use as a delivery vehicle, hydrophilic precursors are usually laden with bioactive moieties and then directly injected to the site of interest for in situ gel formation and controlled release dictated by precursor design. Hydrogels formed by thiol–ene click reactions are attractive for local controlled release of therapeutics owing to their rapid reaction rate and efficiency under mild aqueous conditions, enabling in situ formation of gels with tunable properties often responsive to environmental cues. Herein, we will review the wide range of applications for thiol–ene hydrogels, from the prolonged release of anti-inflammatory drugs in the spine to the release of protein-based therapeutics in response to cell-secreted enzymes, with a focus on their clinical relevance. We will also provide a brief overview of thiol–ene click chemistry and discuss the available alkene chemistries pertinent to macromolecule functionalization and hydrogel formation. These chemistries include functional groups susceptible to Michael type reactions relevant for injection and radically-mediated reactions for greater temporal control of formation at sites of interest using light. Additionally, mechanisms for the encapsulation and controlled release of therapeutic cargoes are reviewed, including i) tuning the mesh size of the hydrogel initially and temporally for cargo entrapment and release and ii) covalent tethering of the cargo with degradable linkers or affinity binding sequences to mediate release. Finally, myriad thiol–ene hydrogels and their specific applications also are discussed to give a sampling of the current and future utilization of this chemistry for delivery of therapeutics, such as small molecule drugs, peptides, and biologics. PMID:28361125

Early crop-tree release and species cleaning in young northern hardwoods: a financial analysis

Treesearch

Paul E. Sendak; William B. Leak

2008-01-01

In 1959 a study of crop-tree release and species cleaning was established in a 25-year-old northern hardwood stand growing on an above-average hardwood site that resulted from a silvicultural clearcut in the White Mountains of New Hampshire. The stand was followed for 5 years and based on the results, treatment effects were projected to a stand age of 45 years. These...

An in situ-forming phospholipid-based phase transition gel prolongs the duration of local anesthesia for ropivacaine with minimal toxicity.

PubMed

Li, Hanmei; Liu, Tao; Zhu, Yuxuan; Fu, Qiang; Wu, Wanxia; Deng, Jie; Lan, Li; Shi, Sanjun

2017-08-01

An injectable, phospholipid-based phase transition gel (PPTG) has been developed for prolonging the release of ropivacaine (RO) for local anesthesia. PPTG was prepared by mixing phospholipids, medium-chain triglyceride and ethanol. Prior to injection, the PPTG is in a sol state with low viscosity. After subcutaneous injection, the PPTG rapidly forms a gel in situ, which acts as a drug release depot as verified by in vitro release profiles and in vivo pharmacokinetics. Administering RO-PPTG to rats led to a significantly smaller initial burst release than administering RO solution or RO base suspension. Nerve blockade in guinea pigs lasted 3-fold longer after injection of RO-PPTG than after injection of RO solution. RO-PPTG showed good biocompatibility and excellent degradability in vivo. These results suggest that this PPTG-based depot system may be useful for sustained release of local anesthetics to prolong analgesia without causing systemic toxicity. The sustained release of local anesthetics at the surgical site after a single injection is the optimal method to control post-surgical pain. In situ forming implant is an attractive alternative for the sustained release of local anesthetics. However, its practical use is highly limited by certain drawbacks including high viscosity, involved toxic organic solvents and fast drug release. To date, phospholipids-based phase transition gel (PPTG) is emerging for clinical development because of the non-toxicity, biocompatibility and ready availability of phospholipids in body. Thus, we present a novel strategy for sustained release of local anesthetics to control post-surgical pain based on PPTG, which showed a prolonged duration of nerve blockade and excellent biocompatibility. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

TSPA 1991: An initial total-system performance assessment for Yucca Mountain; Yucca Mountain Site Characterization Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnard, R.W.; Wilson, M.L.; Dockery, H.A.

1992-07-01

This report describes an assessment of the long-term performance of a repository system that contains deeply buried highly radioactive waste; the system is assumed to be located at the potential site at Yucca Mountain, Nevada. The study includes an identification of features, events, and processes that might affect the potential repository, a construction of scenarios based on this identification, a selection of models describing these scenarios (including abstraction of appropriate models from detailed models), a selection of probability distributions for the parameters in the models, a stochastic calculation of radionuclide releases for the scenarios, and a derivation of complementary cumulativemore » distribution functions (CCDFs) for the releases. Releases and CCDFs are calculated for four categories of scenarios: aqueous flow (modeling primarily the existing conditions at the site, with allowances for climate change), gaseous flow, basaltic igneous activity, and human intrusion. The study shows that models of complex processes can be abstracted into more simplified representations that preserve the understanding of the processes and produce results consistent with those of more complex models.« less

Critical radionuclide/critical pathway analysis for the U.S. Department of Energy's Savannah River Site.

PubMed

Jannik, G T

1999-06-01

Many different radionuclides have been released to the environment from the Savannah River Site (SRS) during the facility's operational history. However, as shown by this analysis, only a small number of the released radionuclides have been significant contributors to potential doses and risks to off-site people. This article documents the radiological critical contaminant/critical pathway analysis performed for SRS. If site missions and operations remain constant over the next 30 years, only tritium oxide releases are projected to exceed a maximally exposed individual (MEI) risk of 1.0E-06 for either the airborne or liquid pathways. The critical exposure pathways associated with site airborne releases are inhalation and vegetation consumption, whereas the critical exposure pathways associated with liquid releases are drinking water and fish consumption. For the SRS-specific, nontypical exposure pathways (i.e., recreational fishing and deer and hog hunting), cesium-137 is the critical radionuclide.

Lack of experience-based stratification in homing pigeon leadership hierarchies.

PubMed

Watts, Isobel; Pettit, Benjamin; Nagy, Máté; de Perera, Theresa Burt; Biro, Dora

2016-01-01

In societies that make collective decisions through leadership, a fundamental question concerns the individual attributes that allow certain group members to assume leadership roles over others. Homing pigeons form transitive leadership hierarchies during flock flights, where flock members are ranked according to the average time differences with which they lead or follow others' movement. Here, we test systematically whether leadership ranks in navigational hierarchies are correlated with prior experience of a homing task. We constructed experimental flocks of pigeons with mixed navigational experience: half of the birds within each flock had been familiarized with a specific release site through multiple previous releases, while the other half had never been released from the same site. We measured the birds' hierarchical leadership ranks, then switched the same birds' roles at a second site to test whether the relative hierarchical positions of the birds in the two subsets would reverse in response to the reversal in levels of experience. We found that while across all releases the top hierarchical positions were occupied by experienced birds significantly more often than by inexperienced ones, the remaining experienced birds were not consistently clustered in the top half-in other words, the network did not become stratified. We discuss our results in light of the adaptive value of structuring leadership hierarchies according to 'merit' (here, navigational experience).

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

Operations of Sandia National Laboratories, Nevada (SNL/NV) at the Tonopah Test Range (TTR) resulted in no planned point radiological releases during 1996. Other releases from SNL/NV included diffuse transuranic sources consisting of the three Clean Slate sites. Air emissions from these sources result from wind resuspension of near-surface transuranic contaminated soil particulates. The total area of contamination has been estimated to exceed 20 million square meters. Soil contamination was documented in an aerial survey program in 1977 (EG&G 1979). Surface contamination levels were generally found to be below 400 pCi/g of combined plutonium-238, plutonium-239, plutonium-240, and americium-241 (i.e., transuranic) activity.more » Hot spot areas contain up to 43,000 pCi/g of transuranic activity. Recent measurements confirm the presence of significant levels of transuranic activity in the surface soil. An annual diffuse source term of 0.39 Ci of transuranic material was calculated for the cumulative release from all three Clean Slate sites. A maximally exposed individual dose of 1.1 mrem/yr at the TTR airport area was estimated based on the 1996 diffuse source release amounts and site-specific meteorological data. A population dose of 0.86 person-rem/yr was calculated for the local residents. Both dose values were attributable to inhalation of transuranic contaminated dust.« less

MARSAME Radiological Release Report for Archaeological Artifacts Excavated from Area L

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruedig, Elizabeth; Whicker, Jeffrey Jay; Gillis, Jessica Mcdonnel

In 1991 Los Alamos National Laboratory’s (LANL’s) cultural resources team excavated archaeological site LA 4618 located at Technical Area 54, within Material Disposal Area L (MDA L). MDA L received non-radioactive chemical waste from the early 1960s until 1985. Further development of the MDA required excavation of several cultural sites under National Historic Preservation Act requirements; artifacts from these sites have been subsequently stored at LANL. The LANL cultural resources group would now like to release these artifacts to the Museum of Indian Arts and Culture in Santa Fe for curation. The history of disposal at Area L suggests thatmore » the artifact pool is unlikely to be chemically contaminated and LANL staff washed each artifact at least once following excavation. Thus, it is unlikely that the artifacts present a chemical hazard. LANL’s Environmental Stewardship group (EPC-ES) has evaluated the radiological survey results for the Area L artifact pool and found that the items described in this report meet the criteria for unrestricted radiological release under Department of Energy (DOE) Order 458.1 Radiation Protection of the Public and the Environment and are candidates for release without restriction from LANL control. This conclusion is based on the known history of MDA L and on radiation survey data.« less

Mucin-mediated nanocarrier disassembly for triggered uptake of oligonucleotides as a delivery strategy for the potential treatment of mucosal tumours

NASA Astrophysics Data System (ADS)

Martirosyan, A.; Olesen, M. J.; Fenton, R. A.; Kjems, J.; Howard, K. A.

2016-06-01

This work demonstrates gastric mucin-triggered nanocarrier disassembly for release of antisense oligonucleotides and consequent unassisted cellular entry as a novel oral delivery strategy. A fluorescence activation-based reporter system was used to investigate the interaction and mucin-mediated disassembly of chitosan-based nanocarriers containing a 13-mer DNA oligonucleotide with a flanked locked RNA nucleic acid gapmer design. Gastric mucins were shown to trigger gapmer release from nanocarriers that was dependent on the interaction time, mucin concentration and N : P ratio with a maximal release at N : P 10. In contrast to siRNA, naked gapmers exhibited uptake into mucus producing HT-MTX mono-cultures and HT-MTX co-cultured with the carcinoma epithelial cell line Caco-2. Importantly, in vivo gapmer uptake was observed in epithelial tissue 30 min post-injection in murine intestinal loops. The findings present a mucosal design-based system tailored for local delivery of oligonucleotides that may maximize the effectiveness of gene silencing therapeutics within tumours at mucosal sites.This work demonstrates gastric mucin-triggered nanocarrier disassembly for release of antisense oligonucleotides and consequent unassisted cellular entry as a novel oral delivery strategy. A fluorescence activation-based reporter system was used to investigate the interaction and mucin-mediated disassembly of chitosan-based nanocarriers containing a 13-mer DNA oligonucleotide with a flanked locked RNA nucleic acid gapmer design. Gastric mucins were shown to trigger gapmer release from nanocarriers that was dependent on the interaction time, mucin concentration and N : P ratio with a maximal release at N : P 10. In contrast to siRNA, naked gapmers exhibited uptake into mucus producing HT-MTX mono-cultures and HT-MTX co-cultured with the carcinoma epithelial cell line Caco-2. Importantly, in vivo gapmer uptake was observed in epithelial tissue 30 min post-injection in murine intestinal loops. The findings present a mucosal design-based system tailored for local delivery of oligonucleotides that may maximize the effectiveness of gene silencing therapeutics within tumours at mucosal sites. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07206a

Air modelling as an alternative to sampling for low-level radioactive airborne releases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgenstern, M.Y.; Hueske, K.

1995-05-01

This paper describes our efforts to assess the effect of airborne releases at one DOE laboratory using air modelling based on historical data. Among the facilities affected by these developments is Los Alamos National Laboratory (LANL) in New Mexico. RCRA, as amended by the Hazardous and Solid Waste Amendments (HSWA) in 1984, requires all facilities which involve the treatment, storage, and disposal of hazardous waste obtain a RCRA/HSWA waste facility permit. LANL complied with CEARP by initiating a process of identifying potential release sites associated with LANL operations prior to filing a RCRA/HSWA permit application. In the process of preparingmore » the RCRA/HSWA waste facility permit application to the U.S. Environmental Protection Agency (EPA), a total of 603 Solid Waste Management Units (SWMUs) were identified as part of the requirements of the HSWA Module VIH permit requirements. The HSWA Module VIII permit requires LANL to determine whether there have been any releases of hazardous waste or hazardous constituents from SWMUs at the facility dating from the 1940`s by performing a RCRA Facility Investigation to address known or suspected releases from specified SWMUs to affected media (i.e. soil, groundwater, surface water, and air). Among the most troublesome of the potential releases sites are those associated with airborne radioactive releases. In order to assess health risks associated with radioactive contaminants in a manner consistent with exposure standards currently in place, the DOE and LANL have established Screening Action Levels (SALs) for radioactive soil contamination. The SALs for each radionuclide in soil are derived from calculations based on a residential scenario in which individuals are exposed to contaminated soil via inhalation and ingestion as well as external exposure to gamma emitters in the soil. The applicable SALs are shown.« less

United States European Command

Science.gov Websites

Organization The Region History Media Library Articles Press Releases Photos Videos Documents Blog Posts Us Press Releases Site Policies Site Translation (Disclaimer) EUCOM's disclaimer regarding this . More in Site Policies External Links Privacy and Security Accessibility/Section 508 Site Translation

Predicting red wolf release success in the southeastern United States

USGS Publications Warehouse

van Manen, Frank T.; Crawford, Barron A.; Clark, Joseph D.

2000-01-01

Although the red wolf (Canis rufus) was once found throughout the southeastern United States, indiscriminate killing and habitat destruction reduced its range to a small section of coastal Texas and Louisiana. Wolves trapped from 1973 to 1980 were taken to establish a captive breeding program that was used to repatriate 2 mainland and 3 island red wolf populations. We collected data from 320 red wolf releases in these areas and classified each as a success or failure based on survival and reproductive criteria, and whether recaptures were necessary to resolve conflicts with humans. We evaluated the relations between release success and conditions at the release sites, characteristics of released wolves, and release procedures. Although <44% of the variation in release success was explained, model performance based on jackknife tests indicated a 72-80% correct prediction rate for the 4 operational models we developed. The models indicated that success was associated with human influences on the landscape and the level of wolf habituation to humans prior to release. We applied the models to 31 prospective areas for wolf repatriation and calculated an index of release success for each area. Decision-makers can use these models to objectively rank prospective release areas and compare strengths and weaknesses of each.

How controlled release technology can aid gene delivery.

PubMed

Jo, Jun-Ichiro; Tabata, Yasuhiko

2015-01-01

Many types of gene delivery systems have been developed to enhance the level of gene expression. Controlled release technology is a feasible gene delivery system which enables genes to extend the expression duration by maintaining and releasing them at the injection site in a controlled manner. This technology can reduce the adverse effects by the bolus dose administration and avoid the repeated administration. Biodegradable biomaterials are useful as materials for the controlled release-based gene delivery technology and various biodegradable biomaterials have been developed. Controlled release-based gene delivery plays a critical role in a conventional gene therapy and genetic engineering. In the gene therapy, the therapeutic gene is released from biodegradable biomaterial matrices around the tissue to be treated. On the other hand, the intracellular controlled release of gene from the sub-micro-sized matrices is required for genetic engineering. Genetic engineering is feasible for cell transplantation as well as research of stem cells biology and medicine. DNA hydrogel containing a sequence of therapeutic gene and the exosome including the individual specific nucleic acids may become candidates for controlled release carriers. Technologies to deliver genes to cell aggregates will play an important role in the promotion of regenerative research and therapy.

Corrective Action Investigation Plan for Corrective Action Unit 569: Area 3 Yucca Flat Atmospheric Test Sites Nevada National Security Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick Matthews; Christy Sloop

2012-02-01

Corrective Action Unit (CAU) 569 is located in Area 3 of the Nevada National Security Site, which is approximately 65 miles northwest of Las Vegas, Nevada. Corrective Action Unit 569 comprises the nine numbered corrective action sites (CASs) and one newly identified site listed below: (1) 03-23-09, T-3 Contamination Area (hereafter referred to as Annie, Franklin, George, and Moth); (2) 03-23-10, T-3A Contamination Area (hereafter referred to as Harry and Hornet); (3) 03-23-11, T-3B Contamination Area (hereafter referred to as Fizeau); (4) 03-23-12, T-3S Contamination Area (hereafter referred to as Rio Arriba); (5) 03-23-13, T-3T Contamination Area (hereafter referred tomore » as Catron); (6) 03-23-14, T-3V Contamination Area (hereafter referred to as Humboldt); (7) 03-23-15, S-3G Contamination Area (hereafter referred to as Coulomb-B); (8) 03-23-16, S-3H Contamination Area (hereafter referred to as Coulomb-A); (9) 03-23-21, Pike Contamination Area (hereafter referred to as Pike); and (10) Waste Consolidation Site 3A. Because CAU 569 is a complicated site containing many types of releases, it was agreed during the data quality objectives (DQO) process that these sites will be grouped. These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each study group. The results of the field investigation will support a defensible evaluation of viable CAAs that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the DQOs developed on September 26, 2011, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 569. The presence and nature of contamination at CAU 569 will be evaluated based on information collected from a field investigation. Radiological contamination will be evaluated based on a comparison of the total effective dose (TED) at sample locations to the dose-based final action level (FAL). The TED will be calculated as the total of separate estimates of internal and external dose. Results from the analysis of soil samples will be used to calculate internal radiological dose. Thermoluminescent dosimeters placed at the center of each sample location will be used to measure external radiological dose. A field investigation will be performed to define any areas where TED exceeds the FAL and to determine whether contaminants of concern are present at the site from other potential releases. The presence and nature of contamination from other types of releases (e.g., excavation, migration, and any potential releases discovered during the investigation) will be evaluated using soil samples collected from biased locations indicating the highest levels of contamination. Appendix A provides a detailed discussion of the DQO methodology and the objectives specific to each study group.« less

Folic acid conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel for site specific delivery of hydrophobic drugs to cancer cells.

PubMed

Pillai, Jisha Jayadevan; Thulasidasan, Arun Kumar Theralikattu; Anto, Ruby John; Chithralekha, Devika Nandan; Narayanan, Ashwanikumar; Kumar, Gopalakrishnapillai Sankaramangalam Vinod

2014-07-15

The hydrogel based system is found to be rarely reported for the delivery of hydrophobic drug due to the incompatibility of hydrophilicity of the polymer network and the hydrophobicity of drug. This problem can be solved by preparing semi-interpenetrating network of cross-linked polymer for tuning the hydrophilicity so as to entrap the hydrophobic drugs. The current study is to develop a folic acid conjugated cross-linked pH sensitive, biocompatible polymeric hydrogel to achieve a site specific drug delivery. For that, we have synthesized a folic acid conjugated PEG cross-linked acrylic polymer (FA-CLAP) hydrogel and investigated its loading and release of curcumin. The formed polymer hydrogel was then conjugated with folic acid for the site specific delivery of curcumin to cancer cells and then further characterized and conducted the cell uptake and cytotoxicity studies on human cervical cancer cell lines (HeLa). In this study, we synthesized folic acid conjugated cross-linked acrylic hydrogel for the delivery of hydrophobic drugs to the cancer site. Poly (ethyleneglycol) (PEG) diacrylate cross-linked acrylic polymer (PAA) was prepared via inverse emulsion polymerization technique and later conjugated it with folic acid (FA-CLAP). Hydrophobic drug curcumin is entrapped into it and investigated the entrapment efficiency. Characterization of synthesized hydogel was done by using Fourier Transform-Infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC). Polymerization and folate conjugation was confirmed by FT-IR spectroscopy. The release kinetics of drug from the entrapped form was studied which showed initial burst release followed by sustained release due to swelling and increased cross-linking. In vitro cytotoxicity and cell uptake studies were conducted in human cervical cancer (HeLa) cell lines. Results showed that curcumin entrapped folate conjugated cross-linked acrylic polymer (FA-CLAP) hydrogel showed higher cellular uptake than the non folate conjugated form. So this can be suggested as a better delivery system for site specific release of hydrophobic cancer drugs.

Effects of exogenous salinity (NaCl) gradient on Cd release in acidified contaminated brown soil

NASA Astrophysics Data System (ADS)

Zhang, Lina; Rong, Yong; Mao, Li; Gao, Zhiyuan; Liu, Xiaoyu; Dong, Zhicheng

2018-02-01

Taking acidified Cd contaminated brown soil in Yantai as the research object, based on different exogenous salinity (NaCl) gradient (0%, 0.3%, 0.6%, 0.9%, 1.5%, 2% and 5%), indoor simulation experiments of Cd release were carried out after field investigation. Results showed that there was a significantly positive relation (r>0.90) between Cd release concentration/amount/ratio and exogenous salt (NaCl). Besides, the more exogenous salt (NaCl) was added; maximum release concentration/amount of Cd appeared the earlier. It was found that exogenous salt (NaCl) addition could obviously promote Cd release from acidified Cd contaminated brown soil. It was believed that this could be mainly due to the cation exchange between Cd2+ and Na+, together with the dissociation and/or complexation between Cl- and Cd2+. In addition, available adsorption sites reduction by exchange base in soil causing Cd changed from solid state to soil solution was also a probable reason.

Injectable and body temperature sensitive hydrogels based on chitosan and hyaluronic acid for pH sensitive drug release.

PubMed

Zhang, Wei; Jin, Xin; Li, Heng; Zhang, Run-Run; Wu, Cheng-Wei

2018-04-15

Hydrogels based on chitosan/hyaluronic acid/β-sodium glycerophosphate demonstrate injectability, body temperature sensitivity, pH sensitive drug release and adhesion to cancer cell. The drug (doxorubicin) loaded hydrogel precursor solutions are injectable and turn to hydrogels when the temperature is increased to body temperature. The acidic condition (pH 4.00) can trigger the release of drug and the cancer cell (Hela) can adhere to the surface of the hydrogels, which will be beneficial for tumor site-specific administration of drug. The mechanical strength, the gelation temperature, and the drug release behavior can be tuned by varying hyaluronic acid content. The mechanisms were characterized using dynamic mechanical analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and fluorescence microscopy. The carboxyl group in hyaluronic acid can form the hydrogen bondings with the protonated amine in chitosan, which promotes the increase of mechanical strength of the hydrogels and depresses the initial burst release of drug from the hydrogel. Copyright © 2018 Elsevier Ltd. All rights reserved.

Does biofilm contribute to diel cycling of Zn in High Ore Creek, Montana?

USGS Publications Warehouse

Morris, J.M.; Nimick, D.A.; Farag, A.M.; Meyer, J.S.

2005-01-01

Concentrations of metals cycle daily in the water column of some mining-impacted streams in the Rocky Mountains of the western USA. We hypothesized that biofilm in High Ore Creek, Montana, USA, sorbs and releases Zn on a diel cycle, and this uptake-and-release cycle controls the total and dissolved (0.45-??m filtered) Zn concentrations. We collected water samples from three sites (upstream, middle and downstream at 0, 350 and 650 m, respectively) along a 650-m reach of High Ore Creek during a 47-h period in August 2002 and from the upstream and downstream sites during a 24-h period in August 2003; we also collected biofilm samples at these sites. In 2002 and 2003, total and dissolved Zn concentrations did not exhibit a diel cycle at the upstream sampling site, which was ???30 m downstream from a settling pond through which the creek flows. However, total and dissolved Zn concentrations exhibited a diel cycle at the middle and downstream sampling sites, with the highest Zn concentrations occurring at dawn and the lowest Zn concentrations occurring during late afternoon (>2-fold range of concentrations at the downstream site). Based on (1) concentrations of Zn in biofilm at the three sites and (2) results of streamside experiments that demonstrated Zn uptake and release by nai??ve biofilm during the light and dark hours of a photocycle, respectively, we conclude that Zn uptake in photosynthetic biofilms could contribute a large percentage to the cycling of Zn concentrations in the water column in High Ore Creek. ?? Springer 2005.

Releasing 75- to 80-year-old Appalachian hardwood sawtimber trees--5-year d.b.h. response

Treesearch

H.C. Smith; G.W. Miller

1991-01-01

Generally, mature trees on good growing sites are seldom thinned or released. Instead, at maturity the trees are harvested. Data were summarized from north-central West Virginia study areas (northern red oak site index 70 feet and above) where mature trees were released on all sides of the crown (full release).

Variation in larval properties of the Atlantic brooding coral Porites astreoides between different reef sites in Bermuda

NASA Astrophysics Data System (ADS)

de Putron, Samantha J.; Lawson, Julia M.; White, Kascia Q. L.; Costa, Matthew T.; Geronimus, Miriam V. B.; MacCarthy, Anne

2017-06-01

Recent research has documented phenotypic differences among larvae released from corals with a brooding reproductive mode, both among species and within broods from a single species. We studied larvae released from the common Atlantic coral Porites astreoides in Bermuda to further evaluate phenotypic variability. Inter-site differences were investigated in larvae from conspecifics at a rim and patch reef site. Larvae were collected daily for one lunar cycle from several colonies per site each year over 5 yr. Larval volume varied with reef site of origin, with colonies from the rim reef site producing larger larvae than colonies from the patch reef site. This inter-site variation in larval size could not be explained by corallite size and may be a response to different environmental conditions at the sites. Larvae from both reef sites also varied in size depending on lunar day of release over 4 yr of study. Regardless of site of origin, smaller larvae were released earlier in the lunar cycle. Over 1 yr of study, lipid and zooxanthellae content and settlement success after 48 h covaried with larval size. However, there may be a trade-off between larger larvae and reduced fecundity. Overall, larvae released from colonies from the rim reef site were larger and had greater settlement success than those from colonies from the patch reef site. This study documents larval phenotypic variability and a distinct inter-site difference in larval ecology among conspecifics within the same geographic area, which may have implications for recruitment success, population dynamics, and resilience.

In situ release rates of Cu and Zn from commercial antifouling paints at different salinities.

PubMed

Lagerström, Maria; Lindgren, J Fredrik; Holmqvist, Albin; Dahlström, Mia; Ytreberg, Erik

2018-02-01

Antifouling paints are environmentally risk assessed based on their biocidal release rates to the water phase. In situ release rates of copper (Cu) and zinc (Zn) were derived for five commercial paints in two recreational marinas with different salinities (5 and 14 PSU) using an X-Ray Fluorescence spectrometer (XRF). Salinity was found to significantly affect the Cu release, with twice the amount of Cu released at the higher salinity, while its influence on the Zn release was paint-specific. Site-specific release rates for water bodies with salinity gradients, e.g. the Baltic Sea, are therefore necessary for more realistic risk assessments of antifouling paints. Furthermore, the in situ release rates were up to 8 times higher than those generated using standardized laboratory or calculation methods. The environmental risk assessment repeated with the field release rates concludes that it is questionable whether the studied products should be allowed on the Swedish market. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Precommercial crop-tree release increases diameter growth of Appalachian hardwood saplings

Treesearch

H. Clay Smith; Neil I. Lamson

1983-01-01

Codominant seedling-origin crop trees 25 to 39 feet tall in even-aged, precommercial-size hardwood stands were released in West Virginia. Trees were located on two sites: good oak site index 75 and fair oak site 63. Species studied were black cherry, sweet birch, and yellow-poplar. Three-year results indicated that the trees generally responded to release; the 3-year...

Atmospheric Propagation Modeling Indicates Homing Pigeons use Loft-Specific Infrasonic 'Map' Cues

NASA Astrophysics Data System (ADS)

Hagstrum, J. T.; Baker, L. M.; Spritzer, J. M.; McKenna, M. H.

2011-12-01

Pigeons (Columba livia) released at distant sites commonly depart in directions significantly off the actual homeward bearing. Such site-dependent deviations, or biases, for birds from a given loft are generally stable over time, but can also change from hour to hour, day to day, and year to year. At some release sites, birds consistently vanish in random directions and have longer flight times and lower return rates. Release sites characterized by frequent disorientation are not uncommon for pigeon lofts in both Europe and the USA. One such site is the Jersey Hill fire tower in upstate New York located ~120 km W of the Cornell loft in Ithaca. Cornell birds released at Jersey Hill between 1968 and 1987 almost always vanished randomly, although birds from other lofts had little difficulty orienting there. The results for one day, however, stand out: on August 13, 1969, Cornell birds released at Jersey Hill vanished consistently to the NE (r = 0.921; n=7) and returned home after normal flight times. Cornell pigeons released the next day again showed 'normal' behavior for the site and departed randomly. If, in fact, the birds are using acoustic cues to navigate, the long-term acoustic 'dead' zone we propose for Jersey Hill, due to prevailing atmospheric conditions, indicates that the cues are coming from a single, relatively restricted area, most likely surrounding the home loft. We have modeled the transmission of infrasonic waves, presumably coupled to the atmosphere from ocean-generated microseisms (0.14 Hz), between the Cornell loft and a number of release sites using HARPA (Hamiltonian Acoustic Ray-tracing Program for the Atmosphere) and rawinsonde data collected near Albany and Buffalo, NY. The HARPA modeling shows that acoustic signals from the Cornell loft reached Jersey Hill only on a few release days with unusual atmospheric conditions, including August 13, and were launched at angles less than ~2° above horizontal, most likely from steep-sided terrain in the loft vicinity. Such low angles would require sound waves to be diffracted around intervening topography, and likely explains why birds released on August 13 vanished from Jersey Hill at a mean direction to the NE (33°) and not closer to the homeward bearing (85°). Cornell birds released at many sites have departure bearings consistent with such topographic effects. At the Dryden III release site just 13 km E of the Cornell loft, pigeons generally departed to the NW (321°, n=630), ~60° off the homeward bearing (258°). Apparently, infrasonic signals from the home loft area were being diffracted around higher terrain between the loft and release site.

Controlled release from aspirin based linear biodegradable poly(anhydride esters) for anti-inflammatory activity.

PubMed

Dasgupta, Queeny; Movva, Sahitya; Chatterjee, Kaushik; Madras, Giridhar

2017-08-07

This work reports the synthesis of a novel, aspirin-loaded, linear poly (anhydride ester) and provides mechanistic insights into the release of aspirin from this polymer for anti-inflammatory activity. As compared to conventional drug delivery systems that rely on diffusion based release, incorporation of bioactives in the polymer backbone is challenging and high loading is difficult to achieve. In the present study, we exploit the pentafunctional sugar alcohol (xylitol) to provide sites for drug (aspirin) attachment at its non-terminal OH groups. The terminal OH groups are polymerized with a diacid anhydride. The hydrolysis of the anhydride and ester bonds under physiological conditions release aspirin from the matrix. The resulting poly(anhydride ester) has high drug loading (53%) and displays controlled release kinetics of aspirin. The polymer releases 8.5 % and 20%, of the loaded drug in one and four weeks, respectively and has a release rate constant of 0.0035h -0.61 . The release rate is suitable for its use as an anti-inflammatory agent without being cytotoxic. The polymer exhibits good cytocompatibility and anti-inflammatory properties and may find applications as injectable or as an implantable bioactive material. The physical insights into the release mechanism can provide development of other drug loaded polymers. Copyright © 2017 Elsevier B.V. All rights reserved.

Near-infrared remotely triggered drug-release strategies for cancer treatment

NASA Astrophysics Data System (ADS)

Goodman, Amanda M.; Neumann, Oara; Nørregaard, Kamilla; Henderson, Luke; Choi, Mi-Ran; Clare, Susan E.; Halas, Naomi J.

2017-11-01

Remotely controlled, localized drug delivery is highly desirable for potentially minimizing the systemic toxicity induced by the administration of typically hydrophobic chemotherapy drugs by conventional means. Nanoparticle-based drug delivery systems provide a highly promising approach for localized drug delivery, and are an emerging field of interest in cancer treatment. Here, we demonstrate near-IR light-triggered release of two drug molecules from both DNA-based and protein-based hosts that have been conjugated to near-infrared-absorbing Au nanoshells (SiO2 core, Au shell), each forming a light-responsive drug delivery complex. We show that, depending upon the drug molecule, the type of host molecule, and the laser illumination method (continuous wave or pulsed laser), in vitro light-triggered release can be achieved with both types of nanoparticle-based complexes. Two breast cancer drugs, docetaxel and HER2-targeted lapatinib, were delivered to MDA-MB-231 and SKBR3 (overexpressing HER2) breast cancer cells and compared with release in noncancerous RAW 264.7 macrophage cells. Continuous wave laser-induced release of docetaxel from a nanoshell-based DNA host complex showed increased cell death, which also coincided with nonspecific cell death from photothermal heating. Using a femtosecond pulsed laser, lapatinib release from a nanoshell-based human serum albumin protein host complex resulted in increased cancerous cell death while noncancerous control cells were unaffected. Both methods provide spatially and temporally localized drug-release strategies that can facilitate high local concentrations of chemotherapy drugs deliverable at a specific treatment site over a specific time window, with the potential for greatly minimized side effects.

Light-switchable systems for remotely controlled drug delivery.

PubMed

Shim, Gayong; Ko, Seungbeom; Kim, Dongyoon; Le, Quoc-Viet; Park, Gyu Thae; Lee, Jaiwoo; Kwon, Taekhyun; Choi, Han-Gon; Kim, Young Bong; Oh, Yu-Kyoung

2017-12-10

Light-switchable systems have recently received attention as a new mode of remotely controlled drug delivery. In the past, a multitude of nanomedicine studies have sought to enhance the specificity of drug delivery to target sites by focusing on receptors overexpressed on malignant cells or environmental features of diseases sites. Despite these immense efforts, however, there are few clinically available nanomedicines. We need a paradigm shift in drug delivery. One strategy that may overcome the limitations of pathophysiology-based drug delivery is the use of remotely controlled delivery technology. Unlike pathophysiology-based active drug targeting strategies, light-switchable systems are not affected by the heterogeneity of cells, tissue types, and/or microenvironments. Instead, they are triggered by remote light (i.e., near-infrared) stimuli, which are absorbed by photoresponsive molecules or three-dimensional nanostructures. The sequential conversion of light to heat or reactive oxygen species can activate drug release and allow it to be spatio-temporally controlled. Light-switchable systems have been used to activate endosomal drug escape, modulate the release of chemical and biological drugs, and alter nanoparticle structures to control the release rates of drugs. This review will address the limitations of pathophysiology-based drug delivery systems, the current status of light-based remote-switch systems, and future directions in the application of light-switchable systems for remotely controlled drug delivery. Copyright © 2017 Elsevier B.V. All rights reserved.

Addendum to the Closure Report for Corrective Action Unit 394: Areas 12, 18, and 29 Spill/Release Sites Nevada Test Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynn Kidman

This document constitutes an addendum to the September 2003, Closure Report for Corrective Action Unit 394: Areas 12, 18, and 29 Spill/Release Sites as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consistsmore » of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the URs for: • CAS 12-25-04, UST 12-16-2 Waste Oil Release • CAS 18-25-01, Oil Spills • CAS 18-25-02, Oil Spills • CAS 18-25-03, Oil Spill • CAS 29-44-01, Fuel Spill These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove these URs because contamination is not present at these sites above the risk-based FALs. Requirements for inspecting and maintaining these URs will be canceled, and the postings and signage at each site will be removed. Fencing and posting may be present at these sites that are unrelated to the FFACO URs such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004f). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at these sites.« less

Crystal structures of the ATP-binding and ADP-release dwells of the V1 rotary motor

PubMed Central

Suzuki, Kano; Mizutani, Kenji; Maruyama, Shintaro; Shimono, Kazumi; Imai, Fabiana L.; Muneyuki, Eiro; Kakinuma, Yoshimi; Ishizuka-Katsura, Yoshiko; Shirouzu, Mikako; Yokoyama, Shigeyuki; Yamato, Ichiro; Murata, Takeshi

2016-01-01

V1-ATPases are highly conserved ATP-driven rotary molecular motors found in various membrane systems. We recently reported the crystal structures for the Enterococcus hirae A3B3DF (V1) complex, corresponding to the catalytic dwell state waiting for ATP hydrolysis. Here we present the crystal structures for two other dwell states obtained by soaking nucleotide-free V1 crystals in ADP. In the presence of 20 μM ADP, two ADP molecules bind to two of three binding sites and cooperatively induce conformational changes of the third site to an ATP-binding mode, corresponding to the ATP-binding dwell. In the presence of 2 mM ADP, all nucleotide-binding sites are occupied by ADP to induce conformational changes corresponding to the ADP-release dwell. Based on these and previous findings, we propose a V1-ATPase rotational mechanism model. PMID:27807367

IRIS Toxicological Review of Libby Amphibole Asbestos ...

EPA Pesticide Factsheets

On August 25, 2011, the draft Toxicological Review of Libby Amphibole Asbestos and the charge to external peer reviewers were released for external peer review and public comment. The Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and White House Offices before public release. In the new IRIS process (May 2009), introduced by the EPA Administrator, all written comments on IRIS assessments submitted by other federal agencies and White House Offices will be made publicly available. Accordingly, interagency comments and the interagency science consultation draft of the IRIS Toxicological Review of Libby Amphibole Asbestos and the charge to external peer reviewers are posted on this site. The project supports OSWER and Region 8 site clean-up and related risk management initiatives at this Superfund site. As with all IRIS assessments, the draft document will undergo agency review, OMB/interagency review and independent external peer review before being included on the IRIS data base.

Predator response to releases of American shad larvae in the Susquehanna River basin

USGS Publications Warehouse

Johnson, James H.; Ringler, N.H.

1998-01-01

Predation on American shad (Alosa sapidissima) larvae within the first two hours of release was examined from 1989 to 1992 on 31 occasions at stocking sites in the Susquehanna River basin. Twenty-two fish species consumed shad larvae; the dominant predators were spotfin shiner (Cyprinella spiloptera), mimic shiner (Notropis volucellus) and juvenile smallmouth bass (Micropterus dolomieu). The number of shad larvae found in predator stomachs ranged from 0 to 900. Mortality of shad larvae at the stocking site was usually less than 2%. The greatest mortality (9.6%) occurred at the highest stocking level (1.5 million larvae). Highly variable predation rates and release levels of shad insufficient to achieve predator satiation hindered the ability to determine a specific type of functional response of predators. Predator numbers increased with stocking density, indicating short-term aggregation at the release site. Because of practical problems associated with releasing the large numbers of larvae that would be required to satiate predators, routine stocking at these levels is probably unreasonable. Releases of 400,000 to 700,000 larvae may reduce predation by offsetting depensatory mechanisms that operate on small releases and the effects of increased predation due to predator aggregation on large releases. Night stocking may reduce predation on larval shad at the release site.

SITE CHARACTERIZATION LIBRARY: VOLUMN 1 (RELEASE 2.5)

EPA Science Inventory

This CD-ROM, Volume 1, Release 2.5, of EPA's National Exposure Research Laboratory (NERL - Las Vegas) Site Characterization Library, contains additional electronic documents and computer programs related to the characterization of hazardous waste sites. EPA has produced this libr...

Readily releasable pool of synaptic vesicles measured at single synaptic contacts.

PubMed

Trigo, Federico F; Sakaba, Takeshi; Ogden, David; Marty, Alain

2012-10-30

To distinguish between different models of vesicular release in brain synapses, it is necessary to know the number of vesicles of transmitter that can be released immediately at individual synapses by a high-calcium stimulus, the readily releasable pool (RRP). We used direct stimulation by calcium uncaging at identified, single-site inhibitory synapses to investigate the statistics of vesicular release and the size of the RRP. Vesicular release, detected as quantal responses in the postsynaptic neuron, showed an unexpected stochastic variation in the number of quanta from stimulus to stimulus at high intracellular calcium, with a mean of 1.9 per stimulus and a maximum of three or four. The results provide direct measurement of the RRP at single synaptic sites. They are consistent with models in which release proceeds from a small number of vesicle docking sites with an average occupancy around 0.7.

Release of specific proteins from nuclei of HL-60 and MOLT-4 cells by antitumor drugs having affinity to nucleic acids.

PubMed

Lassota, P; Melamed, M R; Darzynkiewicz, Z

The binding sites for mitoxantrone (MIT), Ametantrone (AMT), doxorubicin (DOX), actinomycin D (AMD) and ethidium bromide (EB) in nuclei from exponentially growing and differentiating human promyelocytic HL-60 and lymphocytic leukemic MOLT-4 cells were studied by gel electrophoresis of proteins selectively released during titration of these nuclei with the drugs. Each drug at different drug: DNA binding ratios resulted in a characteristic pattern of protein elution and/or retention. For example, in nuclei from exponentially growing HL-60 cells, MIT affected 44 nuclear proteins that were different from those affected by EB; of these 29 were progressively released at increasing MIT:DNA ratios, 11 were transiently released (i.e. only at a low MIT:DNA ratio) and 4 entrapped. Patterns of proteins displaced from nuclei of exponentially growing HL-60 cells differed from those of cells undergoing myeloid differentiation as well as from those of exponentially growing MOLT-4 cells. The first effects were seen at a binding density of approximately one drug molecule per 10-50 base pairs of DNA. The observed selective displacement of proteins may reflect drug-altered affinity of the binding sites for those proteins, for example due to a change of nucleic acid or protein conformation upon binding the ligand. The data show that the binding site(s) for each of the ligands studied is different and the differences correlate with variability in chemical structure between the ligands. The nature of the drug-affected proteins may provide clues regarding antitumor or cytotoxic mechanisms of drug action.

Serotonergic neurosecretory synapse targeting is controlled by Netrin-releasing guidepost neurons in C. elegans

PubMed Central

Nelson, Jessica C.; Colón-Ramos, Daniel A.

2013-01-01

Neurosecretory release sites lack distinct post-synaptic partners, yet target to specific circuits. This targeting specificity regulates local release of neurotransmitters and modulation of adjacent circuits. How neurosecretory release sites target to specific regions is not understood. Here we identify a molecular mechanism that governs the spatial specificity of extrasynaptic neurosecretory terminal formation in the serotonergic NSM neurons of C. elegans. We show that post-embryonic arborization and neurosecretory terminal targeting of the C. elegans NSM neuron is dependent on the Netrin receptor UNC-40/DCC. We observe that UNC-40 localizes to specific neurosecretory terminals at the time of axon arbor formation. This localization is dependent on UNC-6/Netrin, which is expressed by nerve ring neurons that act as guideposts to instruct local arbor and release site formation. We find that both UNC-34/Enabled and MIG-10/Lamellipodin are required downstream of UNC-40 to link the sites of ENT formation to nascent axon arbor extensions. Our findings provide a molecular link between release site development and axon arborization, and introduce a novel mechanism that governs the spatial specificity of serotonergic extrasynaptic neurosecretory terminals in vivo. PMID:23345213

Release and Establishment of the Parasitoid Diachasmimorpha kraussii Against the Tephritid Fruit Fly Bactrocera latifrons in Hawaii

PubMed Central

Bokonon-Ganta, Aimé H.; McQuate, Grant T.; Messing, Russell H.; B. Jang, Eric

2013-01-01

Diachasmimorpha kraussii (Fullaway) (Hymenoptera: Braconidae) was first released against Bactrocera latifrons (Hendel) (Diptera: Tephritidae) in Hawaii in March 2003. Over a three month period, eight releases, totaling 7,696 females and 3,968 males, were made in a turkeyberry, Solanum torvum Swartz (Solanales: Solanaceae) patch known to have a well established B. latifrons population. The establishment of D. kraussii was assessed through fruit collections conducted over a three-year period beyond the last release. D. kraussii was recovered 2 weeks, 31 months, and 39 months after the last parasitoid release, with collections not only from the release site, but also from a control site about 5.0 km distance from the release site. Recovery from fruit collections three years after the last parasitoid release confirmed that D. kraussii had become established in Hawaii. Parasitism rates were low, only 1.0–1.4%, compared to rates of 2.8–8.7% for the earlier established egg-larval parasitoid, Fopius arisanus (Sonan). PMID:23879328

Kinetics and mechanism of release from glyceryl monostearate-based implants: evaluation of release in a gel simulating in vivo implantation.

PubMed

Allababidi, S; Shah, J C

1998-06-01

The overall objective of the study was to design an implantable delivery system based on glyceryl monostearate (GMS) for the site-specific delivery of antibiotics for the prevention of surgical wound infection. To design the implant, a release method had to be developed that simulate the in vivo implantation conditions to be able to predict the release characteristics from the implants when they are actually used in vivo. Also, identifying the release kinetics and mechanism and evaluating the factors that influence the release of drugs from the GMS-based matrix were necessary to allow further design of implants that could yield a desired release rate. The release of cefazolin was monitored from GMS matrixes implanted into agar gel, simulating subcutaneous tissues with respect to viscosity and water content. The gel method resulted in observation of spatial and temporal concentration profiles in the immediate vicinity of the implants, indicating the benefits of local drug delivery; however, there was no significant difference between the cumulative release profiles by the gel method or the vial release method. The release of cefazolin from the GMS-based matrix with the vial method followed Higuchi's square root of time kinetics. The release rate was found to be directly proportional to cefazolin load (A) and the surface area (SA) of the matrix as expressed by the following equation: = 0.24ASA. On the basis of this equation, one can design a variety of GMS matrixes that would result in a desired release rate or release duration. This also indicated that cefazolin release followed the release kinetics of a freely soluble drug from an insoluble matrix and hence it is a diffusion-controlled process. The effect of drug solubility on the release kinetics was determined by comparing the release kinetics of the poorly water soluble ciprofloxacin (0.16 mg/mL) to that of the highly water soluble cefazolin (325 mg/mL). The release duration of ciprofloxacin (80 h) was longer than that of cefazolin (25 h) from identical GMS matrixes. Although ciprofloxacin release was initially controlled by the matrix, agitation accelerated disintegration of the matrix and release due to its poor solubility, and ciprofloxacin release appeared to be a dissolution-controlled process following zero-order release kinetics.

Factors reducing the expected deflection in initial orientation in clock-shifted homing pigeons.

PubMed

Gagliardo, Anna; Odetti, Francesca; Ioalè, Paolo

2005-02-01

To orient from familiar sites, homing pigeons can rely on both an olfactory map and visual familiar landmarks. The latter can in principle be used in two different ways: either within a topographical map exploited for piloting or in a so-called mosaic map associated with a compass bearing. One way to investigate the matter is to put the compass and the topographical information in conflict by releasing clock-shifted pigeons from familiar locations. Although the compass orientation is in general dominant over a piloting strategy, a stronger or weaker tendency to correct towards the home direction by clock-shifted pigeons released from very familiar sites has often been observed. To investigate which factors are involved in the reduction of the deviation due to clock-shift, we performed a series of releases with intact and anosmic pigeons from familiar sites in unshifted and clock-shifted conditions and a series of releases from the same sites with naive clock-shifted birds. Our data suggest that the following factors have a role in reducing deviation due to the clock-shift: familiarity with the release site, the lack of olfactory information and some unknown site-dependent features.

Defining the Structural Basis for Allosteric Product Release from E. coli Dihydrofolate Reductase Using NMR Relaxation Dispersion.

PubMed

Oyen, David; Fenwick, R Bryn; Aoto, Phillip C; Stanfield, Robyn L; Wilson, Ian A; Dyson, H Jane; Wright, Peter E

2017-08-16

The rate-determining step in the catalytic cycle of E. coli dihydrofolate reductase is tetrahydrofolate (THF) product release, which can occur via an allosteric or an intrinsic pathway. The allosteric pathway, which becomes accessible when the reduced cofactor NADPH is bound, involves transient sampling of a higher energy conformational state, greatly increasing the product dissociation rate as compared to the intrinsic pathway that obtains when NADPH is absent. Although the kinetics of this process are known, the enzyme structure and the THF product conformation in the transiently formed excited state remain elusive. Here, we use side-chain proton NMR relaxation dispersion measurements, X-ray crystallography, and structure-based chemical shift predictions to explore the structural basis of allosteric product release. In the excited state of the E:THF:NADPH product release complex, the reduced nicotinamide ring of the cofactor transiently enters the active site where it displaces the pterin ring of the THF product. The p-aminobenzoyl-l-glutamate tail of THF remains weakly bound in a widened binding cleft. Thus, through transient entry of the nicotinamide ring into the active site, the NADPH cofactor remodels the enzyme structure and the conformation of the THF to form a weakly populated excited state that is poised for rapid product release.

Enzymatically cross-linked injectable alginate-g-pyrrole hydrogels for neovascularization.

PubMed

Devolder, Ross; Antoniadou, Eleni; Kong, Hyunjoon

2013-11-28

Microparticles capable of releasing protein drugs are often incorporated into injectable hydrogels to minimize their displacement at an implantation site, reduce initial drug burst, and further control drug release rates over a broader range. However, there is still a need to develop methods for releasing drug molecules over extended periods of time, in order to sustain the bioactivity of drug molecules at an implantation site. In this study, we hypothesized that a hydrogel formed through the cross-linking of pyrrole units linked to a hydrophilic polymer would release protein drugs in a more sustained manner, because of an enhanced association between cross-linked pyrrole groups and the drug molecules. To examine this hypothesis, we prepared hydrogels of alginate substituted with pyrrole groups, alginate-g-pyrrole, through a horse-radish peroxidase (HRP)-activated cross-linking of the pyrrole groups. The hydrogels were encapsulated with poly(lactic-co-glycolic acid) (PLGA) microparticles loaded with vascular endothelial growth factor (VEGF). The resulting hydrogel system released VEGF in a more sustained manner than Ca(2+) alginate or Ca(2+) alginate-g-pyrrole gel systems. Finally, implantations of the VEGF-releasing HRP-activated alginate-g-pyrrole hydrogel system on chicken chorioallantoic membranes resulted in the formation of blood vessels in higher densities and with larger diameters, compared to other control conditions. Overall, the drug releasing system developed in this study will be broadly useful for regulating release rates of a wide array of protein drugs, and further enhance the quality of protein drug-based therapies. © 2013 Elsevier B.V. All rights reserved.

Homing pigeons only navigate in air with intact environmental odours: a test of the olfactory activation hypothesis with GPS data loggers.

PubMed

Gagliardo, Anna; Ioalè, Paolo; Filannino, Caterina; Wikelski, Martin

2011-01-01

A large body of evidence has shown that anosmic pigeons are impaired in their navigation. However, the role of odours in navigation is still subject to debate. While according to the olfactory navigation hypothesis homing pigeons possess a navigational map based on the distribution of environmental odours, the olfactory activation hypothesis proposes that odour perception is only needed to activate a navigational mechanism based on cues of another nature. Here we tested experimentally whether the perception of artificial odours is sufficient to allow pigeons to navigate, as expected from the olfactory activation hypothesis. We transported three groups of pigeons in air-tight containers to release sites 53 and 61 km from home in three different olfactory conditions. The Control group received natural environmental air; both the Pure Air and the Artificial Odour groups received pure air filtered through an active charcoal filter. Only the Artificial Odour group received additional puffs of artificial odours until release. We then released pigeons while recording their tracks with 1 Hz GPS data loggers. We also followed non-homing pigeons using an aerial data readout to a Cessna plane, allowing, for the first time, the tracking of non-homing homing pigeons. Within the first hour after release, the pigeons in both the Artificial Odour and the Pure Air group (receiving no environmental odours) showed impaired navigational performances at each release site. Our data provide evidence against an activation role of odours in navigation, and document that pigeons only navigate well when they perceive environmental odours.

USING A RISK-BASED METHODOLOGY FOR THE TRANSFER OF RADIOACTIVE MATERIAL WITHIN THE SAVANNAH RIVER SITE BOUNDARY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loftin, B; Watkins, R; Loibl, M

2010-06-03

Shipment of radioactive materials (RAM) is discussed in the Code of Federal Regulations in parts of both 49 CFR and 10 CFR. The regulations provide the requirements and rules necessary for the safe shipment of RAM across public highways, railways, waterways, and through the air. These shipments are sometimes referred to as in-commerce shipments. Shipments of RAM entirely within the boundaries of Department of Energy sites, such as the Savannah River Site (SRS), can be made using methodology allowing provisions to maintain equivalent safety while deviating from the regulations for in-commerce shipments. These onsite shipments are known as transfers atmore » the SRS. These transfers must follow the requirements approved in a site-specific Transportation Safety Document (TSD). The TSD defines how the site will transfer materials so that they have equivalence to the regulations. These equivalences are documented in an Onsite Safety Assessment (OSA). The OSA can show how a particular packaging used onsite is equivalent to that which would be used for an in-commerce shipment. This is known as a deterministic approach. However, when a deterministic approach is not viable, the TSD allows for a risk-based OSA to be written. These risk-based assessments show that if a packaging does not provide the necessary safety to ensure that materials are not released (during normal or accident conditions) then the worst-case release of materials does not result in a dose consequence worse than that defined for the SRS. This paper will discuss recent challenges and successes using this methodology at the SRS.« less

Norepinephrine ignites local hot spots of neuronal excitation: How arousal amplifies selectivity in perception and memory

PubMed Central

Mather, Mara; Clewett, David; Sakaki, Michiko; Harley, Carolyn W.

2018-01-01

Long Abstract Existing brain-based emotion-cognition theories fail to explain arousal’s ability to both enhance and impair cognitive processing. In the Glutamate Amplifies Noradrenergic Effects (GANE) model outlined in this paper, we propose that arousal-induced norepinephrine (NE) released from the locus coeruleus (LC) biases perception and memory in favor of salient, high priority representations at the expense of lower priority representations. This increase in gain under phasic arousal occurs via synaptic self-regulation of NE based on glutamate levels. When the LC is phasically active, elevated levels of glutamate at the site of prioritized representations increase local NE release, creating “NE hot spots.” At these local hot spots, glutamate and NE release are mutually enhancing and amplify activation of prioritized representations. This excitatory effect contrasts with widespread NE suppression of weaker representations via lateral and auto-inhibitory processes. On a broader scale, hot spots increase oscillatory synchronization across neural ensembles transmitting high priority information. Furthermore, key brain structures that detect or pre-determine stimulus priority interact with phasic NE release to preferentially route such information through large-scale functional brain networks. A surge of NE before, during or after encoding enhances synaptic plasticity at sites of high glutamate activity, triggering local protein synthesis processes that enhance selective memory consolidation. Together, these noradrenergic mechanisms increase perceptual and memory selectivity under arousal. Beyond explaining discrepancies in the emotion-cognition literature, GANE reconciles and extends previous influential theories of LC neuromodulation by highlighting how NE can produce such different outcomes in processing based on priority. PMID:26126507

Movements of translocated wolves in Minnesota

USGS Publications Warehouse

Fritts, S.H.; Paul, W.J.; Mech, L.D.

1984-01-01

From Feb. 1975-May 1978, 104 wolves (C. lupus) captured at or near Minnesota farms where depredations on livestock had been reported were translocated northward and eastward for 50-317 km into extensive forests; 3 others were released westward. Nine wolves were translocated twice, and 1 three times. Information on movements was obtained by radiotracking 17 wolves and by recovery of 16 others. All radio-tagged wolves left the release areas; adults left quickly, but pups generally remained longer, behaved less decisively, and settled nearby temporarily. Wolves released together did not remain together. Initial travel of most radio-tagged adults was between south and west, the general direction to their original location. Final directions were primarily to the west and northwest, due in part to physiographic barriers. Eight adults homed, 1 twice, to capture areas that were < 64 km from release sites. Nonhoming wolves were radiotracked and/or recovered 32-351 km from their capture sites and 23-302 km from their release sites. Translocation was largely unsuccessful at keeping problem wolves out of lifestock production areas. The problem of initial travel away from release sites in wolf reintroductions probably could be minimized by transport and release of 6-9 mo. old wolves.

Spontaneous and evoked release are independently regulated at individual active zones.

PubMed

Melom, Jan E; Akbergenova, Yulia; Gavornik, Jeffrey P; Littleton, J Troy

2013-10-30

Neurotransmitter release from synaptic vesicle fusion is the fundamental mechanism for neuronal communication at synapses. Evoked release following an action potential has been well characterized for its function in activating the postsynaptic cell, but the significance of spontaneous release is less clear. Using transgenic tools to image single synaptic vesicle fusion events at individual release sites (active zones) in Drosophila, we characterized the spatial and temporal dynamics of exocytotic events that occur spontaneously or in response to an action potential. We also analyzed the relationship between these two modes of fusion at single release sites. A majority of active zones participate in both modes of fusion, although release probability is not correlated between the two modes of release and is highly variable across the population. A subset of active zones is specifically dedicated to spontaneous release, indicating a population of postsynaptic receptors is uniquely activated by this mode of vesicle fusion. Imaging synaptic transmission at individual release sites also revealed general rules for spontaneous and evoked release, and indicate that active zones with similar release probability can cluster spatially within individual synaptic boutons. These findings suggest neuronal connections contain two information channels that can be spatially segregated and independently regulated to transmit evoked or spontaneous fusion signals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Patrick K.

This Corrective Action Decision Document/Closure Report presents information supporting the closure of Corrective Action Unit (CAU) 550: Smoky Contamination Area, Nevada National Security Site, Nevada. CAU 550 includes 19 corrective action sites (CASs), which consist of one weapons-related atmospheric test (Smoky), three safety experiments (Ceres, Oberon, Titania), and 15 debris sites (Table ES-1). The CASs were sorted into the following study groups based on release potential and technical similarities: • Study Group 1, Atmospheric Test • Study Group 2, Safety Experiments • Study Group 3, Washes • Study Group 4, Debris The purpose of this document is to provide justificationmore » and documentation supporting the conclusion that no further corrective action is needed for CAU 550 based on implementation of the corrective actions listed in Table ES-1. Corrective action investigation (CAI) activities were performed between August 2012 and October 2013 as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 550: Smoky Contamination Area; and in accordance with the Soils Activity Quality Assurance Plan. The approach for the CAI was to investigate and make data quality objective (DQO) decisions based on the types of releases present. The purpose of the CAI was to fulfill data needs as defined during the DQO process. The CAU 550 dataset of investigation results was evaluated based on a data quality assessment. This assessment demonstrated the dataset is complete and acceptable for use in fulfilling the DQO data needs.« less

40 CFR 300.440 - Procedures for planning and implementing off-site response actions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... under section 311 of the Clean Water Act where the release poses an immediate and significant threat to... to CERCLA wastes from cleanup actions based on CERCLA decision documents signed or consent decrees lodged after October 17, 1986 (“post-SARA CERCLA wastes”) as well as those based on CERCLA decision...

Control of drug release through the in situ assembly of stimuli-responsive ordered mesoporous silica with magnetic particles.

PubMed

Zhu, Shenmin; Zhou, Zhengyang; Zhang, Di

2007-12-03

A site-selective controlled delivery system for controlled drug release is fabricated through the in situ assembly of stimuli-responsive ordered SBA-15 and magnetic particles. This approach is based on the formation of ordered mesoporous silica with magnetic particles formed from Fe(CO)5 via the surfactant-template sol-gel method and control of transport through polymerization of N-isopropyl acrylamide inside the pores. Hydrophobic Fe(CO)5 acts as a swelling agent as well as being the source of the magnetic particles. The obtained system demonstrates a high pore diameter (7.1 nm) and pore volume (0.41 cm(3) g(-1)), which improves drug storage for relatively large molecules. Controlled drug release through the porous network is demonstrated by measuring the uptake and release of ibuprofen (IBU). The delivery system displays a high IBU storage capacity of 71.5 wt %, which is almost twice as large as the highest value based on SBA-15 ever reported. In vitro testing of IBU loading and release exhibits a pronounced transition at around 32 degrees C, indicating a typical thermosensitive controlled release.

BIOCHLOR: NATURAL ATTENUATION DECISION SUPPORT SYSTEM, USER'S MANUAL, VERSION 1.0

EPA Science Inventory

BIOCHLOR is an easy-to-use screening model that simulates remediation by natural attenuation (RNA) of dissolved solvents at chlorinated solvent release sites. The software, programmed in the Microsoft Excel spreadsheet environment and based on the Domenico analytical solute tran...

BIOSCREEN: NATURAL ATTENTUATION DECISION SUPPORT SYSTEM - USER'S MANUAL, VERSION 1.3

EPA Science Inventory

BIOSCREEN is an easy-to-use screening model which simulates remediation through natural attenuation (RNA) of dissolved hydrocarbons at petroleum fuel release sites. The software, programmed in the Microsoft Excel spreadsheet environment and based on the Domenico analytical solu...

Pathway-based monitoring of biological effects at Great Lakes sites (Presntation)

EPA Science Inventory

The Great Lakes region suffers from degradation of water and environmental quality due to release of chemicals of emerging concern. Critical issues remain in delisting Areas of Concern (AOC) including determining sources of chemicals causing fish health impacts, relating health ...

Localization of PKA Phosphorylation Site, Serine-2030, in the Three-Dimensional Structure of Cardiac Ryanodine Receptor

PubMed Central

Jones, Peter P.; Meng, Xing; Xiao, Bailong; Cai, Shitian; Bolstad, Jeff; Wagenknecht, Terence; Liu, Zheng; Chen, S. R. Wayne

2009-01-01

Protein kinase A (PKA)-dependent phosphorylation of the cardiac Ca2+ release channel/ryanodine receptor (RyR2) is believed to directly dissociate FKBP12.6 from the channel, causing abnormal channel activation and Ca2+ release. To gain insight into the structural basis of the regulation of RyR2 by PKA, we determined the three-dimensional location of the PKA site S2030. Green fluorescent protein (GFP) was inserted into the wild type (wt) RyR2 and RyR2 mutant, A4860G, after T2023. The resultant GFP-RyR2 fusion proteins, RyR2T2023-GFP and RyR2(A4860G)T2023-GFP, were expressed in HEK293 cells and functionally characterized. Ca2+ release assays revealed that both GFP-RyR2 fusion proteins formed caffeine- and ryanodine-sensitive Ca2+ release channels. Further analyses using [3H]ryanodine binding demonstrated that the insertion of GFP into RyR2 wt after T2023 reduced the sensitivity of the channel to activation by Ca2+ or caffeine. RyR2(A4860G)T2023-GFP was found to be structurally more stable than RyR2T2023-GFP and was subsequently used as a basis for three-dimensional reconstruction. Cryo-electron microscopy and single particle image processing of the purified RyR2(A4860G)T2023-GFP protein revealed the location of the inserted GFP, and hence the S2030 PKA site in domain 4, a region that may be involved in signal transduction between the transmembrane and cytoplasmic domains. Like the S2808 PKA site reported previously, the S2030 site is not located close to the FKBP12.6 binding site mapped previously, indicating that neither of these PKA sites is directly involved in FKBP12.6 binding. Based on the three-dimensional localizations of a number of residues or regions, a model for the subunit organization in the structure of RyR2 is proposed. PMID:17967164

Highly Efficient Release of Glycopeptides from Hydrazide Beads by Hydroxylamine Assisted PNGase F Deglycosylation for N-Glycoproteome Analysis.

PubMed

Huang, Junfeng; Wan, Hao; Yao, Yating; Li, Jinan; Cheng, Kai; Mao, Jiawei; Chen, Jin; Wang, Yan; Qin, Hongqiang; Zhang, Weibing; Ye, Mingliang; Zou, Hanfa

2015-10-20

Selective enrichment of glycopeptides from complex sample followed by cleavage of N-glycans by PNGase F to expose an easily detectable mark on the former glycosylation sites has become the popular protocol for comprehensive glycoproteome analysis. On account of the high enrichment specificity, hydrazide chemistry based solid-phase extraction of N-linked glycopeptides technique has sparked numerous interests. However, the enzymatic release of glycopeptides captured by hydrazide beads through direct incubation of the beads with PNGase F is not efficient due to the inherent steric hindrance effect. In this study, we developed a hydroxylamine assisted PNGase F deglycosylation (HAPD) method using the hydroxylamine to release glycopeptides captured on the hydrazide beads through the cleavage of hydrazone bonds by transamination followed with the PNGase F deglycosylation of the released glycopeptides in the free solution. Because of the homogeneous condition for the deglycosylation, the recovery of deglycosylated peptides (deglycopeptides) was improved significantly. It was found that 27% more N-glycosylation sites were identified by the HAPD strategy compared with the conventional method. Moreover, the ratio of identified N-terminal glycosylated peptides was improved over 5-fold.

Resource Selection by the California Condor (Gymnogyps californianus) Relative to Terrestrial-Based Habitats and Meteorological Conditions

PubMed Central

Rivers, James W.; Johnson, J. Matthew; Haig, Susan M.; Schwarz, Carl J.; Glendening, John W.; Burnett, L. Joseph; George, Daniel; Grantham, Jesse

2014-01-01

Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to this critically endangered species. PMID:24523893

Resource selection by the California condor (Gymnogyps californianus) relative to terrestrial-based habitats and meteorological conditions

USGS Publications Warehouse

Johnson, J. Matthew; Haig, Susan M.; Schwarz, Carl J.; Glendening, John W.; Burnett, L. Joseph; George, Daniel; Grantham, Jesse

2014-01-01

Condors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to this critically endangered species.

Improved Tumor-Specific Drug Accumulation by Polymer Therapeutics with pH-Sensitive Drug Release Overcomes Chemotherapy Resistance.

PubMed

Heinrich, Anne-Kathrin; Lucas, Henrike; Schindler, Lucie; Chytil, Petr; Etrych, Tomáš; Mäder, Karsten; Mueller, Thomas

2016-05-01

The success of chemotherapy is limited by poor selectivity of active drugs combined with occurrence of tumor resistance. New star-like structured N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-based drug delivery systems containing doxorubicin attached via a pH-sensitive hydrazone bond were designed and investigated for their ability to overcome chemotherapy resistance. These conjugates combine two strategies to achieve a high drug concentration selectively at the tumor site: (I) high accumulation by passive tumor targeting based on enhanced permeability and retention effect and (II) pH-sensitive site-specific drug release due to an acidic tumor microenvironment. Mice bearing doxorubicin-resistant xenograft tumors were treated with doxorubicin, PBS, poly HPMA (pHPMA) precursor or pHPMA-doxorubicin conjugate at different equivalent doses of 5 mg/kg bodyweight doxorubicin up to a 7-fold total dose using different treatment schedules. Intratumoral drug accumulation was analyzed by fluorescence imaging utilizing intrinsic fluorescence of doxorubicin. Free doxorubicin induced significant toxicity but hardly any tumor-inhibiting effects. Administering at least a 3-fold dose of pHPMA-doxorubicin conjugate was necessary to induce a transient response, whereas doses of about 5- to 6-fold induced strong regressions. Tumors completely disappeared in some cases. The onset of response was differential delayed depending on the tumor model, which could be ascribed to distinct characteristics of the microenvironment. Further fluorescence imaging-based analyses regarding underlying mechanisms of the delayed response revealed a related switch to a more supporting intratumoral microenvironment for effective drug release. In conclusion, the current study demonstrates that the concept of tumor site-restricted high-dose chemotherapy is able to overcome therapy resistance. Mol Cancer Ther; 15(5); 998-1007. ©2016 AACR. ©2016 American Association for Cancer Research.

Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956)- An Assessment of Quantities released, Off-Site Radiation Doses, and Potential Excess Risks of Thyroid Cancer, Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Apostoaei, A.I.; Burns, R.E.; Hoffman, F.O.

1999-07-01

In the early 1990s, concern about the Oak Ridge Reservation's past releases of contaminants to the environment prompted Tennessee's public health officials to pursue an in-depth study of potential off-site health effects at Oak Ridge. This study, the Oak Ridge dose reconstruction, was supported by an agreement between the U.S. Department of Energy (DOE) and the State of Tennessee, and was overseen by a 12-member panel appointed by Tennessee's Commissioner of Health. One of the major contaminants studied in the dose reconstruction was radioactive iodine, which was released to the air by X-10 (now called Oak Ridge National Laboratory) asmore » it processed spent nuclear reactor fuel from 1944 through 1956. The process recovered radioactive lanthanum for use in weapons development. Iodine concentrates in the thyroid gland so health concerns include various diseases of the thyroid, such as thyroid cancer. The large report, ''Iodine-131 Releases from Radioactive Lanthanum Processing at the X-10 Site in Oak Ridge, Tennessee (1944-1956) - An Assessment of Quantities Released, Off-site Radiation Doses, and Potential Excess Risks of Thyroid Cancer,'' is in two volumes. Volume 1 is the main body of the report, and Volume 1A, which has the same title, consists of 22 supporting appendices. Together, these reports serve the following purposes: (1) describe the methodologies used to estimate the amount of iodine-131 (I-131) released; (2) evaluate I-131's pathway from air to vegetation to food to humans; (3) estimate doses received by human thyroids; (4) estimate excess risk of acquiring a thyroid cancer during ones lifetime; and (5) provide equations, examples of historical documents used, and tables of calculated values. Results indicate that females born in 1952 who consumed milk from a goat pastured a few miles east of X-10 received the highest doses from I-131 and would have had the highest risks of contracting thyroid cancer. Doses from cow's milk are considerably less . Detailed dose and risk estimates, and associated uncertainties, for other contaminants studied for the Oak Ridge dose reconstruction are presented in several other technical reports. One way to easily locate them in OSTI's Information Bridge is by searching the ''report number field'' for the number DOE/OR/21981*. Be sure to place the asterisk after the base number so your search can list the complete series of reports related to Oak Ridge Dose Reconstruction.« less

Ten years of change: National Library of Medicine TOXMAP gets a new look.

PubMed

Hochstein, Colette; Gemoets, Darren; Goshorn, Jeanne

2014-01-01

The United States National Library of Medicine (NLM) TOXNET® databases < http://toxnet.nlm.nih.gov > provide broad coverage of environmental health information covering a wide variety of topics, including access to the U.S. Environment Protection Agency (EPA)'s Toxics Release Inventory (TRI) data. The NLM web-based geographic information system (GIS), TOXMAP® < http://toxmap.nlm.nih.gov/ >, provides interactive maps which show where TRI chemicals are released into the environment and links to TOXNET for information about these chemicals. TOXMAP also displays locations of Superfund sites on the EPA National Priority List, as well as information about the chemical contaminants at these sites. This column focuses on a new version of TOXMAP which brings it up to date with current web GIS technologies and user expectations.

Pathway-based monitoring of biological effects at Great Lakes sites

EPA Science Inventory

The Great Lakes region suffers from degradation of water and environmental quality due to release of chemicals of emerging concern (CEC) that may threaten near shore health. Critical issues remain in delisting AOC including determining sources of chemicals causing fish health im...

STEAM INJECTION REMEDIATION IN FRACTURED BEDROCK AT LORING AIR FORCE BASE

EPA Science Inventory

Contaminated groundwater occurs at many Superfund, RCRA, and Brownfields sites. Chlorinated solvents which can form a dense nonaqueous phase (DNAPL) when released to the subsurface can pose an extreme challenge for remediation, as DNAPLs are often difficult to locate and even ha...

INFLUENCE OF STRATIGRAPHY ON A DIVING MTBE PLUME AND ITS CHARACTERIZATION: A CASE STUDY

EPA Science Inventory

Conventional conceptual models applied at petroleum release sites are often based on assumptions of vertical contaminant migration through the vadose zone followed by horizontal, downgradient transport at the water table with limited, if any, additional downward migration. Howev...

Occurrence of select perfluoroalkyl substances at U.S. Air Force aqueous film-forming foam release sites other than fire-training areas: Field-validation of critical fate and transport properties.

PubMed

Anderson, R Hunter; Long, G Cornell; Porter, Ronald C; Anderson, Janet K

2016-05-01

The use of aqueous film-forming foam (AFFF) to extinguish hydrocarbon-based fires is recognized as a significant source of environmental poly- and perfluoroalkyl substances (PFASs). Although the occurrence of select PFASs in soil and groundwater at former fire-training areas (FTAs) at military installations operable since 1970 has been consistently confirmed, studies reporting the occurrence of PFASs at other AFFF-impacted sites (e.g. emergency response locations, AFFF lagoons, hangar-related AFFF storage tanks and pipelines, and fire station testing and maintenance areas) are largely missing from the literature. Further, studies have mostly focused on a single site (i.e., FTAs at military installations) and, thus, lack a comparison of sites with diverse AFFF release history. Therefore, the purpose of this investigation was to evaluate select PFAS occurrence at non-FTA sites on active U.S. Air Force installations with historic AFFF use of varying magnitude. Concentrations of fifteen perfluoroalkyl acids (PFAAs) and perfluorooctane sulfonamide (PFOSA), an important PFOS precursor, were measured from several hundred samples among multiple media (i.e., surface soil, subsurface soil, sediment, surface water, and groundwater) collected from forty AFFF-impacted sites across ten installations between March and September 2014, representing one of the most comprehensive datasets on environmental PFAS occurrence to date. Differences in detection frequencies and observed concentrations due to AFFF release volume are presented along with rigorous data analyses that quantitatively demonstrate phase-dependent (i.e., solid-phase vs aqueous-phase) differences in the chemical signature as a function of carbon chain-length and in situ PFOS (and to a slightly lesser extent PFHxS) formation, presumably due to precursor biotransformation. Published by Elsevier Ltd.

Molecular scaffold reorganization at the transmitter release site with vesicle exocytosis or botulinum toxin C1.

PubMed

Stanley, Elise F; Reese, Tom S; Wang, Gary Z

2003-10-01

Neurotransmitter release sites at the freeze-fractured frog neuromuscular junction are composed of inner and outer paired rows of large membrane particles, the putative calcium channels, anchored by the ribs of an underlying protein scaffold. We analysed the locations of the release site particles as a reflection of the scaffold structure, comparing particle distributions in secreting terminals with those where secretion was blocked with botulinum toxin A, which cleaves a small segment off SNAP-25, or botulinum toxin C1, which cleaves the cytoplasmic domain of syntaxin. In the idle terminal the inner and outer paired rows were located approximately 25 and approximately 44 nm, respectively, from the release site midline. However, adjacent to vesicular fusion sites both particle rows were displaced towards the midline by approximately 25%. The intervals between the particles along each row were examined by a nearest-neighbour approach. In control terminals the peak interval along the inner row was approximately 17 nm, consistent with previous reports and the spacing of the scaffold ribs. While the average distance between particles in the outer row was also approximately 17 nm, a detailed analysis revealed short 'linear clusters' with a approximately 14 nm interval. These clusters were enriched at vesicle fusion sites, suggesting an association with the docking sites, and were eliminated by botulinum C1, but not A. Our findings suggest, first, that the release site scaffold ribs undergo a predictable, and possibly active, shortening during exocytosis and, second, that at the vesicle docking site syntaxin plays a role in the cross-linking of the rib tips to form the vesicle docking sites.

Reported implementation lessons from a national quality improvement initiative; Productive Ward: Releasing Time to Care™. A qualitative, ward-based team perspective.

PubMed

White, Mark; Butterworth, Tony; Wells, John S G

2017-10-01

To explore the experiences of participants involved in the implementation of the Productive Ward: Releasing Time to Care™ initiative in Ireland, identifying key implementation lessons. A large-scale quality improvement programme Productive Ward: Releasing Time to Care™ was introduced nationwide into Ireland in 2011. We captured accounts from ward-based teams in an implementation phase during 2013-14 to explore their experiences. Semi-structured, in-depth interviews with a purposive sample of 24 members of ward-based teams from nine sites involved in the second national phase of the initiative were conducted. Interviews were analysed and coded under themes, using a seven-stage iterative process. The predominant theme identified was associated with the implementation and management of the initiative and included: project management; training; preparation; information and communication; and participant's negative experiences. The most prominent challenge reported related to other competing clinical priorities. Despite the structured approach of Productive Ward: Releasing Time to Care™, it appears that overstretched and busy clinical environments struggle to provide the right climate and context for ward-based teams to engage and interact actively with quality improvement tools, methods and activities. Findings highlight five key aspects of implementation and management that will help facilitate successful adoption of large-scale, ward-based quality improvement programmes such as Productive Ward: Releasing Time to Care™. Utilising pre-existing implementation or quality frameworks to assess each ward/unit for 'readiness' prior to commencing a quality improvement intervention such as Productive Ward: Releasing Time to Care™ should be considered. © 2017 John Wiley & Sons Ltd.

Effects of recreational flow releases on natural resources of the Indian and Hudson Rivers in the Central Adirondack Mountains, New York, 2004-06

USGS Publications Warehouse

Baldigo, Barry P.; Mulvihill, C.I.; Ernst, A.G.; Boisvert, B.A.

2011-01-01

The U.S. Geological Survey (USGS), the New York State Department of Environmental Conservation (NYSDEC), and Cornell University carried out a cooperative 2-year study from the fall of 2004 through the fall of 2006 to characterize the potential effects of recreational-flow releases from Lake Abanakee on natural resources in the Indian and Hudson Rivers. Researchers gathered baseline information on hydrology, temperature, habitat, nearshore wetlands, and macroinvertebrate and fish communities and assessed the behavior and thermoregulation of stocked brown trout in study reaches from both rivers and from a control river. The effects of recreational-flow releases (releases) were assessed by comparing data from affected reaches with data from the same reaches during nonrelease days, control reaches in a nearby run-of-the-river system (the Cedar River), and one reach in the Hudson River upstream from the confluence with the Indian River. A streamgage downstream from Lake Abanakee transmitted data by satellite from November 2004 to November 2006; these data were used as the basis for developing a rating curve that was used to estimate discharges for the study period. River habitat at most study reaches was delineated by using Global Positioning System and ArcMap software on a handheld computer, and wetlands were mapped by ground-based measurements of length, width, and areal density. River temperature in the Indian and Hudson Rivers was monitored continuously at eight sites during June through September of 2005 and 2006; temperature was mapped in 2005 by remote imaging made possible through collaboration with the Rochester Institute of Technology. Fish communities at all study reaches were surveyed and characterized through quantitative, nearshore electrofishing surveys. Macroinvertebrate communities in all study reaches were sampled using the traveling-kick method and characterized using standard indices. Radio telemetry was used to track the movement and persistence of stocked brown trout (implanted with temperature-sensitive transmitters) in the Indian and Hudson Rivers during the summer of 2005 and in all three rivers during the summer of 2006. The releases had little effect on river temperatures, but increased discharges by about one order of magnitude. Regardless of the releases, river temperatures at all study sites commonly exceeded the threshold known to be stressful to brown trout. At most sites, mean and median water temperatures on release days were not significantly different, or slightly lower, than water temperatures on nonrelease days. Most differences were very small and, thus, were probably not biologically meaningful. The releases generally increased the total surface area of fast-water habitat (rapids, runs, and riffles) and decreased the total surface area of slow-water habitat (pools, glides, backwater areas, and side channels). The total surface areas of wetlands bordering the Indian River were substantially smaller than the surface areas bordering the Cedar River; however, no channel geomorphology or watershed soil and topographic data were assessed to determine whether the releases or other factors were mainly responsible for observed differences. Results from surveys of resident biota indicate that the releases generally had a limited effect on fish and macroinvertebrate communities in the Indian River and had no effect on communities in the Hudson River. Compared to fish data from Cedar River control sites, the impoundment appeared to reduce total density, biomass, and richness in the Indian River at the first site downstream from Lake Abanakee, moderately reduce the indexes at the other two sites on the Indian River, and slightly reduce the indexes at the first Hudson River site downstream from the confluence with the Indian River. The densities of individual fish populations at all Indian River sites were also reduced, but related effects on fish populations in the Hudson River were less evident. Altho

Estimating the number of airports potentially contaminated with perfluoroalkyl and polyfluoroalkyl substances from aqueous film forming foam: A Canadian example.

PubMed

Milley, Shawn A; Koch, Iris; Fortin, Patricia; Archer, Jeremy; Reynolds, David; Weber, Kela P

2018-09-15

Assessing the extent to which emerging contaminants (ECs) such as perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been released into the environment is one of the foundations for developing effective management and remediation strategies for impacted sites. PFAS are known to have caused the contamination of soil, groundwater, and surface water as a result of aqueous film forming foam (AFFF) being accidentally or intentionally released into the environment. To date, the scope of the issue has not been evaluated in Canada. In this study we developed a framework, in the form of a decision tree, to estimate the number of potentially PFAS impacted airport sites in Canada as a result of AFFF releases. The screening process was completed using publicly available resources including airport websites, the Canadian Owners and Pilots Association website, Sky Vector, Transport Safety Board of Canada aviation investigation reports, the Aviation Safety Network website, and Google maps. The methodology presented in this study could be used to identify additional PFAS impacted sites in Canada or other jurisdictions worldwide. 2071 airport/heliport sites in Canada were investigated with indications that 152 (7%) of these sites likely have PFAS contamination as a result of the use of AFFF at firefighter training areas (FFTAs) and/or accidents where fires occurred. In addition, another 268 sites (13%) were identified as possibly impacted with PFASs primarily as a result of the location having the ability to store and dispense petroleum products, and therefore having AFFF systems onsite. Surficial geology was also identified for all sites determined to likely have PFAS contamination. An estimated 42.8% had surficial geology composed of sand, 27% had clay, 19.7% organic-based, with the remaining sites found on cryosols or rock. Methodological validation was also completed. The procedure used in this study successfully predicted occurrences of PFAS contamination at 25 sites where contamination, as a result of AFFF use, was confirmed by Canadian governmental departments. For these 25 sites, the distance from potential release areas to the nearest surface water was calculated. Five of the sites were within 200 meters of surface water, 19 were within one kilometer, and all 25 were within 2.5 kilometers. This suggests that surface water may have been historically impacted by PFAS at as many as 152 to 420 different airport locations in Canada. Copyright © 2018 Elsevier Ltd. All rights reserved.

Adjunctive Effects of A Piscean Collagen-Based Controlled-Release Chlorhexidine Chip in the Treatment of Chronic Periodontitis: A Clinical and Microbiological Study

PubMed Central

John, Priya; Lazarus, Flemingson; Selvam, Arul; Prabhuji, Munivenkatappa Lakshmaiah Venkatesh

2015-01-01

Introduction PerioChip a bovine origin gelatine based CHX chip has shown beneficial effects in the management of Chronic Periodontitis. A new fish collagen based CHX chip similar to PerioChip is currently available; however this product has not been thoroughly researched. Aim The aim of the present study was to evaluate the effectiveness of a new Piscean collagen-based controlled-release chlorhexidine chip (CHX chip) as an adjunctive therapy to scaling and root planing (SRP). Settings and Design The study was conducted as a randomised, split-mouth, controlled clinical trial at Krishnadevaraya College of Dental Sciences, Bangalore, India. Materials and Methods In a split–mouth study involving 20 sites in 10 patients with chronic periodontitis, control sites received scaling and root planing and test sites received scaling and root planing (SRP) and the intrapocket CHX chip placement as an adjunct. Subgingival plaque samples were collected from both control and test sites at baseline, 11 days and 11 weeks and the anaerobic colony count were assessed. Clinical parameters that were recorded at baseline and 11 weeks were gingival index, Plaque index, Probing pocket depth (PPD), and Clinical attachment level (CAL). Plaque index was recorded additionally at 11 days. Results In the test group there was a statistically significant reduction in the total anaerobic colony count, gingival index and plaque scores from baseline as compared to control sites at all time intervals. An additional 0.8mm reduction in mean probing pocket depth was noted in the test group. Gain in Clinical attachment level was comparable in both groups. Conclusion The adjunctive use of the new collagen-based CHX chip yielded significant antimicrobial benefit accompanied by a reduction in probing depth and a clinical attachment level gain as compared to SRP alone. This suggests that it may be a useful treatment option of nonsurgical periodontal treatment of chronic periodontitis. PMID:26155567

Crown releasing of red maple poles to shorten high-quality sawlog rotations

Treesearch

Gayne G. Erdmann; Ralph M., Jr. Peterson; Robert R. Orberg

1985-01-01

The effects of six crown-release treatments on growth and bole quality development of 54-year-old dominant, codominant, and intermediate red maples (Acer rubrum L.) were evaluated on a good red maple site (site index = 19.3 mat 50 years) in upper Michigan. Results showed that crown release stimulated the growth of dominants, codominants, and strong...

Poa secunda local collections and commercial releases: A genotypic evaluation

PubMed Central

Shaw, Alanna N.; Mummey, Daniel L.

2017-01-01

The genetics of native plants influence the success of ecological restoration, yet genetic variability of local seed collections and commercial seed releases remains unclear for most taxa. Poa secunda, a common native grass species in Intermountain West grasslands and a frequent component of restoration seed mixes, is one such species. Here, we evaluate the genetic variation of local Poa secunda collections in the context of wild populations and commercial seed releases. We evaluated AFLP markers for seven Poa secunda collections made over a 4000-hectare area and four commercial releases (High Plains, MT-1, Opportunity, and Sherman). We compare the genetic distance and distribution of genetic variation within and between local collections and commercial releases. The extent and patterns of genetic variation in our local collections indicate subtle site differences with most variation occurring within rather than between collections. Identical genetic matches were usually, but not always, found within 5 m2 collection sites. Our results suggest that the genetic variation in two Poa secunda releases (High Plains and MT-1) is similar to our local collections. Our results affirm that guidelines for Poa secunda seed collection should follow recommendations for selfing species, by collecting from many sites over large individual sites. PMID:28369130

Poa secunda local collections and commercial releases: A genotypic evaluation.

PubMed

Shaw, Alanna N; Mummey, Daniel L

2017-01-01

The genetics of native plants influence the success of ecological restoration, yet genetic variability of local seed collections and commercial seed releases remains unclear for most taxa. Poa secunda, a common native grass species in Intermountain West grasslands and a frequent component of restoration seed mixes, is one such species. Here, we evaluate the genetic variation of local Poa secunda collections in the context of wild populations and commercial seed releases. We evaluated AFLP markers for seven Poa secunda collections made over a 4000-hectare area and four commercial releases (High Plains, MT-1, Opportunity, and Sherman). We compare the genetic distance and distribution of genetic variation within and between local collections and commercial releases. The extent and patterns of genetic variation in our local collections indicate subtle site differences with most variation occurring within rather than between collections. Identical genetic matches were usually, but not always, found within 5 m2 collection sites. Our results suggest that the genetic variation in two Poa secunda releases (High Plains and MT-1) is similar to our local collections. Our results affirm that guidelines for Poa secunda seed collection should follow recommendations for selfing species, by collecting from many sites over large individual sites.

Validation of a Janus role of methotrexate-based PEGylated chitosan nanoparticles in vitro

NASA Astrophysics Data System (ADS)

Luo, Fanghong; Li, Yang; Jia, Mengmeng; Cui, Fei; Wu, Hongjie; Yu, Fei; Lin, Jinyan; Yang, Xiangrui; Hou, Zhenqing; Zhang, Qiqing

2014-07-01

Recently, methotrexate (MTX) has been used to target to folate (FA) receptor-overexpressing cancer cells for targeted drug delivery. However, the systematic evaluation of MTX as a Janus-like agent has not been reported before. Here, we explored the validity of using MTX playing an early-phase cancer-specific targeting ligand cooperated with a late-phase therapeutic anticancer agent based on the PEGylated chitosan (CS) nanoparticles (NPs) as drug carriers. Some advantages of these nanoscaled drug delivery systems are as follows: (1) the NPs can ensure minimal premature release of MTX at off-target site to reduce the side effects to normal tissue; (2) MTX can function as a targeting ligand at target site prior to cellular uptake; and (3) once internalized by the target cell, the NPs can function as a prodrug formulation, releasing biologically active MTX inside the cells. The (MTX + PEG)-CS-NPs presented a sustained/proteases-mediated drug release. More importantly, compared with the PEG-CS-NPs and (FA + PEG)-CS-NPs, the (MTX + PEG)-CS-NPs showed a greater cellular uptake. Furthermore, the (MTX + PEG)-CS-NPs demonstrated a superior cytotoxicity compare to the free MTX. Our findings therefore validated that the MTX-loaded PEGylated CS-NPs can simultaneously target and treat FA receptor-overexpressing cancer cells.

The pertinence of Sutton's law to exposure science: Lessons from unconventional shale gas drilling.

PubMed

Goldstein, Bernard D

2018-01-04

Sutton's Law urges the medical practitioner to utilize the test that goes directly to the problem. When applied to exposure science, Sutton's Law would argue that the major emphasis should be on techniques that directly measure exposure in or close to the human, animal or ecosystem receptors of concern. Exposure science largely and appropriately violates Sutton's Law by estimating exposure based on information on emissions or measurements obtained at a distance from the receptors of concern. I suggest four criteria to help determine whether Sutton's law should be violated for an innovative technology, and explore these criteria in relation to potential human exposure resulting from unconventional gas drilling (UGD): (1) The technological processes possibly leading to release of the chemical or physical agents of concern are reasonably understood; (2) the agents of concern are known; (3) the source and geographical location of the releases can be reasonably identified; and (4) there is information about the likely temporal pattern of the releases and resulting pollutant levels in relation to the temporal patterns of receptor susceptibility. For UGD, the complexity of the technology including many possible release points at different time periods; the existence of three variable mixtures of chemical and physical agents as well as possible unknown reactants; the demonstrated large variation in releases from site to site; and deficiencies in transparency and regulatory oversight, all suggest that studies of the potential health impact of UGD should follow Sutton's Law. This includes the use of techniques that more directly measure exposure close to or within the receptors of concern, such as biological markers or through community-based citizen science. Understanding the implications of Sutton's Law could help focus scientific and regulatory efforts on effective approaches to evaluate the potential health and ecosystem implications of new and evolving technologies.

Photo-triggered release from liposomes without membrane solubilization, based on binding to poly(vinyl alcohol) carrying a malachite green moiety.

PubMed

Uda, Ryoko M; Kato, Yutaka; Takei, Michiko

2016-10-01

When working with liposomes analogous to cell membranes, it is important to develop substrates that can regulate interactions with the liposome surface in response to light. We achieved a photo-triggered release from liposomes by using a copolymer of poly(vinyl alcohol) carrying a malachite green moiety (PVAMG). Although PVAMG is a neutral polymer under dark conditions, it is photoionized upon exposure to UV light, resulting in the formation of a cationic site for binding to liposomes with a negatively charged surface. Under UV irradiation, PVAMG showed effective interaction with liposomes, releasing the encapsulated compound; however, this release was negligible under dark conditions. The poly(vinyl alcohol) moiety of PVAMG played an important role in the photo-triggered release. This release was caused by membrane destabilization without lipid solubilization. We also investigated different aspects of liposome/PVAMG interactions, including PVAMG-induced fusion between the liposomes and the change in the liposome morphologies. Copyright © 2016 Elsevier B.V. All rights reserved.

Installation Restoration Program. Preliminary Assessment: 192nd Tactical Fighter Group, Virginia Air National Guard, Richmond International Airport, Sandston, Virginia

DTIC Science & Technology

1989-02-01

contaminated by past disposal practices. Sampling and analysis was not included in the PA. B. MAJOR FINDINGS The Air National Guard has utilized...with 23 Base personnel and the field surveys identified 3 potentially contaminated sites resulting from past disposal, storage, and/or spills and leaks...characteristic petroleum odor. With visible evidence of released contaminants , there is potential for contaminant migration by shallow groundwater. Site No. 3

Soviet test yields

NASA Astrophysics Data System (ADS)

Vergino, Eileen S.

Soviet seismologists have published descriptions of 96 nuclear explosions conducted from 1961 through 1972 at the Semipalatinsk test site, in Kazakhstan, central Asia [Bocharov et al., 1989]. With the exception of releasing news about some of their peaceful nuclear explosions (PNEs) the Soviets have never before published such a body of information.To estimate the seismic yield of a nuclear explosion it is necessary to obtain a calibrated magnitude-yield relationship based on events with known yields and with a consistent set of seismic magnitudes. U.S. estimation of Soviet test yields has been done through application of relationships to the Soviet sites based on the U.S. experience at the Nevada Test Site (NTS), making some correction for differences due to attenuation and near-source coupling of seismic waves.

Open release of male mosquitoes infected with a wolbachia biopesticide: field performance and infection containment.

PubMed

O'Connor, Linda; Plichart, Catherine; Sang, Ayo Cheong; Brelsfoard, Corey L; Bossin, Hervé C; Dobson, Stephen L

2012-01-01

Lymphatic filariasis (LF) is a globally significant disease, with 1.3 billion persons in 83 countries at risk. A coordinated effort of administering annual macrofilaricidal prophylactics to the entire at-risk population has succeeded in impacting and eliminating LF transmission in multiple regions. However, some areas in the South Pacific are predicted to persist as transmission sites, due in part to the biology of the mosquito vector, which has led to a call for additional tools to augment drug treatments. Autocidal strategies against mosquitoes are resurging in the effort against invasive mosquitoes and vector borne disease, with examples that include field trials of genetically modified mosquitoes and Wolbachia population replacement. However, critical questions must be addressed in anticipation of full field trials, including assessments of field competitiveness of transfected males and the risk of unintended population replacement. We report the outcome of field experiments testing a strategy that employs Wolbachia as a biopesticide. The strategy is based upon Wolbachia-induced conditional sterility, known as cytoplasmic incompatibility, and the repeated release of incompatible males to suppress a population. A criticism of the Wolbachia biopesticide approach is that unintended female release or horizontal Wolbachia transmission can result in population replacement instead of suppression. We present the outcome of laboratory and field experiments assessing the competitiveness of transfected males and their ability to transmit Wolbachia via horizontal transmission. The results demonstrate that Wolbachia-transfected Aedes polynesiensis males are competitive under field conditions during a thirty-week open release period, as indicated by mark, release, recapture and brood-hatch failure among females at the release site. Experiments demonstrate the males to be 'dead end hosts' for Wolbachia and that methods were adequate to prevent population replacement at the field site. The findings encourage the continued development and extension of a Wolbachia autocidal approach to additional medically important mosquito species.

Technical Report Series on Global Modeling and Data Assimilation. Volume 40; Soil Moisture Active Passive (SMAP) Project Assessment Report for the Beta-Release L4_SM Data Product

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Liu, Qing; Colliander, Andreas; Conaty, Austin; Jackson, Thomas; Kimball, John

2015-01-01

During the post-launch SMAP calibration and validation (Cal/Val) phase there are two objectives for each science data product team: 1) calibrate, verify, and improve the performance of the science algorithm, and 2) validate the accuracy of the science data product as specified in the science requirements and according to the Cal/Val schedule. This report provides an assessment of the SMAP Level 4 Surface and Root Zone Soil Moisture Passive (L4_SM) product specifically for the product's public beta release scheduled for 30 October 2015. The primary objective of the beta release is to allow users to familiarize themselves with the data product before the validated product becomes available. The beta release also allows users to conduct their own assessment of the data and to provide feedback to the L4_SM science data product team. The assessment of the L4_SM data product includes comparisons of SMAP L4_SM soil moisture estimates with in situ soil moisture observations from core validation sites and sparse networks. The assessment further includes a global evaluation of the internal diagnostics from the ensemble-based data assimilation system that is used to generate the L4_SM product. This evaluation focuses on the statistics of the observation-minus-forecast (O-F) residuals and the analysis increments. Together, the core validation site comparisons and the statistics of the assimilation diagnostics are considered primary validation methodologies for the L4_SM product. Comparisons against in situ measurements from regional-scale sparse networks are considered a secondary validation methodology because such in situ measurements are subject to upscaling errors from the point-scale to the grid cell scale of the data product. Based on the limited set of core validation sites, the assessment presented here meets the criteria established by the Committee on Earth Observing Satellites for Stage 1 validation and supports the beta release of the data. The validation against sparse network measurements and the evaluation of the assimilation diagnostics address Stage 2 validation criteria by expanding the assessment to regional and global scales.

Extending the Lunar Mapping and Modeling Portal - New Capabilities and New Worlds

NASA Astrophysics Data System (ADS)

Day, Brian; Law, Emily

2015-11-01

NASA’s Lunar Mapping and Modeling Portal (LMMP) provides a web-based Portal and a suite of interactive visualization and analysis tools to enable mission planners, lunar scientists, and engineers to access mapped lunar data products from past and current lunar missions (http://lmmp.nasa.gov). During the past year, the capabilities and data served by LMMP have been significantly expanded. New interfaces are providing improved ways to access and visualize data. Many of the recent enhancements to LMMP have been specifically in response to the requirements of NASA's proposed Resource Prospector lunar rover, and as such, provide an excellent example of the application of LMMP to mission planning.At the request of NASA’s Science Mission Directorate, LMMP’s technology and capabilities are now being extended to additional planetary bodies. New portals for Vesta and Mars are the first of these new products to be released.On March 31, 2015, the LMMP team released Vesta Trek (http://vestatrek.jpl.nasa.gov), a web-based application applying LMMP technology to visualize the asteroid Vesta. Data gathered from multiple instruments aboard Dawn have been compiled into Vesta Trek’s user-friendly set of tools, enabling users to study the asteroid’s features.Released on July 1, 2015, Mars Trek replicates the functionality of Vesta Trek for the surface of Mars. While the entire surface of Mars is covered, higher levels of resolution and greater numbers of data products are provided for special areas of interest. Early releases focus on past, current, and future robotic sites of operation. Future releases will add many new data products and analysis tools as Mars Trek has been selected for use in site selection for the Mars 2020 rover and in identifying potential human landing sites on Mars.Other destinations will follow soon. The Solar Sytem Exploration Research Virtual Institute, which manages the project, invites the user community to provide suggestions and requests as the development team continues to expand the capabilities of these portals.This presentation will provide an overview of all three portals, demonstrate their uses and capabilities, highlight new features, and preview coming enhancements.

Extending the Lunar Mapping and Modeling Portal - New Capabilities and New Worlds

NASA Astrophysics Data System (ADS)

Day, B. H.; Law, E.; Arevalo, E.; Bui, B.; Chang, G.; Dodge, K.; Kim, R. M.; Malhotra, S.; Sadaqathullah, S.

2015-12-01

NASA's Lunar Mapping and Modeling Portal (LMMP) provides a web-based Portal and a suite of interactive visualization and analysis tools to enable mission planners, lunar scientists, and engineers to access mapped lunar data products from past and current lunar missions (http://lmmp.nasa.gov). During the past year, the capabilities and data served by LMMP have been significantly expanded. New interfaces are providing improved ways to access and visualize data. Many of the recent enhancements to LMMP have been specifically in response to the requirements of NASA's proposed Resource Prospector lunar rover, and as such, provide an excellent example of the application of LMMP to mission planning. At the request of NASA's Science Mission Directorate, LMMP's technology and capabilities are now being extended to additional planetary bodies. New portals for Vesta and Mars are the first of these new products to be released. On March 31, 2015, the LMMP team released Vesta Trek (http://vestatrek.jpl.nasa.gov), a web-based application applying LMMP technology to visualizations of the asteroid Vesta. Data gathered from multiple instruments aboard Dawn have been compiled into Vesta Trek's user-friendly set of tools, enabling users to study the asteroid's features. With an initial release on July 1, 2015, Mars Trek replicates the functionality of Vesta Trek for the surface of Mars. While the entire surface of Mars is covered, higher levels of resolution and greater numbers of data products are provided for special areas of interest. Early releases focus on past, current, and future robotic sites of operation. Future releases will add many new data products and analysis tools as Mars Trek has been selected for use in site selection for the Mars 2020 rover and in identifying potential human landing sites on Mars. Other destinations will follow soon. The user community is invited to provide suggestions and requests as the development team continues to expand the capabilities of LMMP, its related products, and the range of data and tools that they provide. This presentation will provide an overview of LMMP, Vesta Trek, and Mars Trek, demonstrate their uses and capabilities, highlight new features, and preview coming enhancements.

Sulfur Dioxide Emission Rates of Kilauea Volcano, Hawaii, 1979-1997

USGS Publications Warehouse

Elias, Tamar; Sutton, A.J.; Stokes, J.B.; Casadevall, T.J.

1998-01-01

INTRODUCTION Sulfur dioxide (SO2) emission rates from Kilauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Casadevall and others, 1987; Greenland and others, 1985; Elias and others, 1993; Elias and Sutton, 1996). The purpose of this report is to present a compilation of Kilauea SO2 emission rate data from 1979 through 1997 with ancillary meteorological data (wind speed and wind direction). We have included measurements previously reported by Casadevall and others (1987) for completeness and to improve the usefulness of this current database compilation. Kilauea releases SO2 gas predominantly from its summit caldera and rift zones (fig. 1). From 1979 through 1982, vehicle-based COSPEC measurements made within the summit caldera were adequate to quantify most of the SO2 emitted from the volcano. Beginning in 1983. the focus of SO2 release shifted from the summit to the east rift zone (ERZ) eruption site at Pu'u 'O'o and, later, Kupaianaha. Since 1984, the Kilauea gas measurement effort has been augmented with intermittent airborne and tripod-based surveys made near the ERZ eruption site. In addition, beginning in 1992 vehicle-based measurements have been made along a section of Chain of Craters Road approximately 9 km downwind of the eruption site. These several types of COSPEC measurements continue to the present.

A prodrug-doped cellular Trojan Horse for the potential treatment of prostate cancer.

PubMed

Levy, Oren; Brennen, W Nathaniel; Han, Edward; Rosen, David Marc; Musabeyezu, Juliet; Safaee, Helia; Ranganath, Sudhir; Ngai, Jessica; Heinelt, Martina; Milton, Yuka; Wang, Hao; Bhagchandani, Sachin H; Joshi, Nitin; Bhowmick, Neil; Denmeade, Samuel R; Isaacs, John T; Karp, Jeffrey M

2016-06-01

Despite considerable advances in prostate cancer research, there is a major need for a systemic delivery platform that efficiently targets anti-cancer drugs to sites of disseminated prostate cancer while minimizing host toxicity. In this proof-of-principle study, human mesenchymal stem cells (MSCs) were loaded with poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) that encapsulate the macromolecule G114, a thapsigargin-based prostate specific antigen (PSA)-activated prodrug. G114-particles (∼950 nm in size) were internalized by MSCs, followed by the release of G114 as an intact prodrug from loaded cells. Moreover, G114 released from G114 MP-loaded MSCs selectively induced death of the PSA-secreting PCa cell line, LNCaP. Finally, G114 MP-loaded MSCs inhibited tumor growth when used in proof-of-concept co-inoculation studies with CWR22 PCa xenografts, suggesting that cell-based delivery of G114 did not compromise the potency of this pro-drug in-vitro or in-vivo. This study demonstrates a potentially promising approach to assemble a cell-based drug delivery platform, which inhibits cancer growth in-vivo without the need of genetic engineering. We envision that upon achieving efficient homing of systemically infused MSCs to cancer sites, this MSC-based platform may be developed into an effective, systemic 'Trojan Horse' therapy for targeted delivery of therapeutic agents to sites of metastatic PCa. Copyright © 2016 Elsevier Ltd. All rights reserved.

Implications of matrix diffusion on 1,4-dioxane persistence at contaminated groundwater sites.

PubMed

Adamson, David T; de Blanc, Phillip C; Farhat, Shahla K; Newell, Charles J

2016-08-15

Management of groundwater sites impacted by 1,4-dioxane can be challenging due to its migration potential and perceived recalcitrance. This study examined the extent to which 1,4-dioxane's persistence was subject to diffusion of mass into and out of lower-permeability zones relative to co-released chlorinated solvents. Two different release scenarios were evaluated within a two-layer aquifer system using an analytical modeling approach. The first scenario simulated a 1,4-dioxane and 1,1,1-TCA source zone where spent solvent was released. The period when 1,4-dioxane was actively loading the low-permeability layer within the source zone was estimated to be <3years due to its high effective solubility. While this was approximately an order-of-magnitude shorter than the loading period for 1,1,1-TCA, the mass of 1,4-dioxane stored within the low-permeability zone at the end of the simulation period (26kg) was larger than that predicted for 1,1,1-TCA (17kg). Even 80years after release, the aqueous 1,4-dioxane concentration was still several orders-of-magnitude higher than potentially-applicable criteria. Within the downgradient plume, diffusion contributed to higher concentrations and enhanced penetration of 1,4-dioxane into the low-permeability zones relative to 1,1,1-TCA. In the second scenario, elevated 1,4-dioxane concentrations were predicted at a site impacted by migration of a weak source from an upgradient site. Plume cutoff was beneficial because it could be implemented in time to prevent further loading of the low-permeability zone at the downgradient site. Overall, this study documented that 1,4-dioxane within transmissive portions of the source zone is quickly depleted due to characteristics that favor both diffusion-based storage and groundwater transport, leaving little mass to treat using conventional means. Furthermore, the results highlight the differences between 1,4-dioxane and chlorinated solvent source zones, suggesting that back diffusion of 1,4-dioxane mass may be serving as the dominant long-term "secondary source" at many contaminated sites that must be managed using alternative approaches. Copyright © 2016 Elsevier B.V. All rights reserved.

Orientation of pigeons exposed to constant light and released from familiar sites.

PubMed

Dall'Antonia, P; Luschi, P

1993-12-01

It has been proposed that homing pigeons may use pilotage to orient home when released from familiar sites. To test this possibility, a group of pigeons was released from familiar locations after being exposed to a constant bright light. This treatment produced the loss of the circadian rhythmicity of general activity of the birds and thus presumably impaired their time-compensating sun compass mechanism. Experimental birds, both anosmic and olfactorily unimpaired, did not show any tendency to orient home, their bearing distributions being generally not different from random. Their homing performances were also affected. These results show that initial orientation of pigeons released from familiar sites entails the use of the sun compass even when the birds are released after a treatment that makes them arrhythmic in their activity. The possibility that pilotage may play a role in the first part of the homing flight of pigeons remains to be demonstrated.

Honey bees can perform accurately directed waggle dances based solely on information from a homeward trip.

PubMed

Edrich, Wolfgang

2015-10-01

Honey bees were displaced several 100 m from their hive to an unfamiliar site and provisioned with honey. After feeding, almost two-thirds of the bees flew home to their hive within a 50 min observation time. About half of these returning, bees signalled the direction of the release site in waggle dances thus demonstrating that the dance can be guided entirely by information gathered on a single homeward trip. The likely reason for the bees' enthusiastic dancing on their initial return from this new site was the highly rewarding honeycomb that they were given there. The attractive nature of the site is confirmed by many of these bees revisiting the site and continuing to forage there.

Hanford Site 100-N Area In Situ Bioremediation of UPR-100-N-17, Deep Petroleum Unplanned Release - 13245

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saueressig, Daniel G.

2013-07-01

In 1965 and 1966, approximately 303 m{sup 3} of Number 2 diesel fuel leaked from a pipeline used to support reactor operations at the Hanford Site's N Reactor. N Reactor was Hanford's longest operating reactor and served as the world's first dual purpose reactor for military and power production needs. The Interim Action Record of Decision for the 100-N Area identified in situ bioremediation as the preferred alternative to remediate the deep vadose zone contaminated by this release. A pilot project supplied oxygen into the vadose zone to stimulate microbial activity in the soil. The project monitored respiration rates asmore » an indicator of active biodegradation. Based on pilot study results, a full-scale system is being constructed and installed to remediate the vadose zone contamination. (authors)« less

42 CFR 73.14 - Incident response.

Code of Federal Regulations, 2013 CFR

2013-10-01

... under this part must develop and implement a written incident response plan based upon a site specific risk assessment.2 The incident response plan must be coordinated with any entity-wide plans, kept in... response plan must fully describe the entity's response procedures for the theft, loss, or release of a...

42 CFR 73.14 - Incident response.

Code of Federal Regulations, 2014 CFR

2014-10-01

... under this part must develop and implement a written incident response plan based upon a site specific risk assessment.2 The incident response plan must be coordinated with any entity-wide plans, kept in... response plan must fully describe the entity's response procedures for the theft, loss, or release of a...

DOE Office of Scientific and Technical Information (OSTI.GOV)

K.E. Rasmuson

The U.S. Department of Energy has implemented a program to reclaim lands disturbed by site characterization at Yucca Mountain. Long term goals of the program are to re-establish processes on disturbed sites that will lead to self-sustaining plant communities. The Biological Opinion for Yucca Mountain Site Characterization Studies required that the U.S. Department of Energy develop a Reclamation Standards and Monitoring Plan to evaluate the success of reclamation efforts. According to the Reclamation Standards and Monitoring Plan, reclaimed sites will be monitored periodically, remediated if necessary, and eventually compared to an appropriate reference area to determine whether reclamation goals havemore » been achieved and the site can be released from further monitoring. Plant cover, density, and species richness (success parameters) on reclaimed sites are compared to 60 percent of the values (success criteria) for the same parameters on the reference area. Small sites (less than 0.1 ha) are evaluated for release using qualitative methods while large sites (greater than 0.1 ha) are evaluated using quantitative methods. In the summer of 2000, 31 small sites reclaimed in 1993 and 1994 were evaluated for reclamation success and potential release from further monitoring. Plant density, cover, and species richness were estimated on the C-Well Pipeline, UE-25 Large Rocks test site, and 29 ground surface facility test pits. Evidence of erosion, reproduction and natural recruitment, exotic species abundance, and animal use (key attributes) also were recorded for each site and used in success evaluations. The C-Well Pipeline and ground surface facility test pits were located in a ''Larrea tridentata - Ephedra nevadensis'' vegetation association while the UE-25 Large Rocks test site was located in an area dominated by ''Coleogyne ramosissima and Ephedra nevadensis''. Reference areas in the same vegetation associations with similar slope and aspect were chosen for comparison to the reclaimed sites. Sixty percent of the reference area means for density, cover, and species richness were compared to the estimated means for the reclaimed sites. Plant density, cover, and species richness at the C-Well Pipeline and UE-25 Large Rocks test site were greater than the success criteria and all key attributes indicated the sites were in acceptable condition. Therefore, these two sites were recommended for release from further monitoring. Of the 29 ground surface facility test pits, 26 met the criterion for density, 21 for cover, and 23 for species richness. When key attributes and conditions of the plant community near each pit were taken into account, 27 of these pits were recommended for release. Success parameters and key attributes at ground surface facility test pits 19 and 20 were inadequate for site release. Transplants of native species were added to these two sites in 2001 to improve density, cover, and species richness.« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1987. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 70 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for reach of the sites is a histogram showing the fraction of the total population within 2 to 80 kmmore » around each site receiving various average dose commitments from the airborne pathways. The site average individual dose commitment from all pathways ranged from a low of 2 {times} 10{sup {minus}6} mrem to a high of 0.009 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year). 2 refs., 2 figs., 7 tabs.« less

Singly applied herbicides for site preparation and release of loblolly pine in central Georgia

Treesearch

James H. Miller; M. Boyd Edwards

1995-01-01

Abstract.Separate studies were installed to evaluate site-preparation and release herbicide treatments for loblolly pine.(Pinus taeda L.).Tests were at four locations each on the Piedmont and Coastal Plain of central Georgia.

Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS.

A reappraisal of drug release laws using Monte Carlo simulations: the prevalence of the Weibull function.

PubMed

Kosmidis, Kosmas; Argyrakis, Panos; Macheras, Panos

2003-07-01

To verify the Higuchi law and study the drug release from cylindrical and spherical matrices by means of Monte Carlo computer simulation. A one-dimensional matrix, based on the theoretical assumptions of the derivation of the Higuchi law, was simulated and its time evolution was monitored. Cylindrical and spherical three-dimensional lattices were simulated with sites at the boundary of the lattice having been denoted as leak sites. Particles were allowed to move inside it using the random walk model. Excluded volume interactions between the particles was assumed. We have monitored the system time evolution for different lattice sizes and different initial particle concentrations. The Higuchi law was verified using the Monte Carlo technique in a one-dimensional lattice. It was found that Fickian drug release from cylindrical matrices can be approximated nicely with the Weibull function. A simple linear relation between the Weibull function parameters and the specific surface of the system was found. Drug release from a matrix, as a result of a diffusion process assuming excluded volume interactions between the drug molecules, can be described using a Weibull function. This model, although approximate and semiempirical, has the benefit of providing a simple physical connection between the model parameters and the system geometry, which was something missing from other semiempirical models.

Redox and pH dual-responsive mesoporous silica nanoparticles for site-specific drug delivery

NASA Astrophysics Data System (ADS)

Wang, Ying; Cui, Yu; Huang, Jiahao; Di, Donghua; Dong, Yanyan; Zhang, Xiaojing; Zhao, Qinfu; Han, Ning; Gao, Yikun; Jiang, Tongying; Wang, Siling

2015-11-01

In this paper, a mesoporous silica nanoparticles (MSN)-based redox and pH dual-responsive delivery system (MSN-SS-PAA) was developed for site-specific drug delivery, in which poly(acrylic acid) (PAA), a polyanion polymer, was grafted on the outlets of MSN via the cleavable disulfide bonds. PAA was chosen as a gatekeeper to block drugs within the mesopores of MSN mainly because PAA possesses many favorable features, such as appropriate molecular weight to block the entrances of MSNs, good biocompatibility, and ability to prolong the blood circulation time and improve the dispersing stability of MSN in physiological conditions. RhB, a fluorescent dye, was used as a model drug. In vitro release profiles indicated that RhB was markedly blocked within the mesopores in the absence of GSH or in pH 7.4 PBS; however, the release of RhB was dramatically increased after the addition of GSH or in pH 5.0 PBS. Moreover, the release of RhB was further improved in the simultaneous presence of GSH and pH 5.0 PBS. This paper provided an exploration of stimuli-responsive delivery system and the results demonstrated that MSN-SS-PAA exhibiting dual-responsive drug release property can be further considered as a promising candidate for cancer therapy.

Corrective action investigation plan for Corrective Action Unit 340, Pesticide Release Sites, Nevada Test Site, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This Correction Action Investigation Plan (CAIP) has been developed in accordance with the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the US Department of Energy, Nevada Operations Office (DOE/NV); the State of Nevada Division of Environmental Protection (NDEP); and the US Department of Defense. As required by the FFACO (1996), this document provides or references all of the specific information for planning investigation activities associated with three Corrective Action Sites (CASs) located at the Nevada Test Site (NTS). These CASs are collectively known as Corrective Action Unit (CAU) 340, Pesticide Release Sites. According to themore » FFACO, CASs are sites that may require corrective action(s) and may include solid waste management units or individual disposal or release sites. These sites are CAS 23-21-01, Area 23 Quonset Hut 800 (Q800) Pesticide Release Ditch; CAS 23-18-03, Area 23 Skid Huts Pesticide Storage; and CAS 15-18-02, Area 15 Quonset Hut 15-11 Pesticide Storage (Q15-11). The purpose of this CAIP for CAU 340 is to direct and guide the investigation for the evaluation of the nature and extent of pesticides, herbicides, and other contaminants of potential concern (COPCs) that were stored, mixed, and/or disposed of at each of the CASs.« less

NESHAP Dose-Release Factor Isopleths for Five Source-to-Receptor Distances from the Center of Site and H-Area for all Compass Sectors at SRS using CAP88-PC Version 4.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trimor, P.

The Environmental Protection Agency (EPA) requires the use of the computer model CAP88-PC to estimate the total effective doses (TED) for demonstrating compliance with 40 CFR 61, Subpart H (EPA 2006), the National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. As such, CAP88 Version 4.0 was used to calculate the receptor dose due to routine atmospheric releases at the Savannah River Site (SRS). For estimation, NESHAP dose-release factors (DRFs) have been supplied to Environmental Compliance and Area Closure Projects (EC&ACP) for many years. DRFs represent the dose to a maximum receptor exposed to 1 Ci of a specified radionuclidemore » being released into the atmosphere. They are periodically updated to include changes in the CAP88 version, input parameter values, site meteorology, and location of the maximally exposed individual (MEI). This report presents the DRFs of tritium oxide released at two onsite locations, center-of-site (COS) and H-Area, at 0 ft. elevation to maximally exposed individuals (MEIs) located 1000, 3000, 6000, 9000, and 12000 meters from the release areas for 16 compass sectors. The analysis makes use of area-specific meteorological data (Viner 2014).« less

Protein pharmacophore selection using hydration-site analysis

PubMed Central

Hu, Bingjie; Lill, Markus A.

2012-01-01

Virtual screening using pharmacophore models is an efficient method to identify potential lead compounds for target proteins. Pharmacophore models based on protein structures are advantageous because a priori knowledge of active ligands is not required and the models are not biased by the chemical space of previously identified actives. However, in order to capture most potential interactions between all potentially binding ligands and the protein, the size of the pharmacophore model, i.e. number of pharmacophore elements, is typically quite large and therefore reduces the efficiency of pharmacophore based screening. We have developed a new method to select important pharmacophore elements using hydration-site information. The basic premise is that ligand functional groups that replace water molecules in the apo protein contribute strongly to the overall binding affinity of the ligand, due to the additional free energy gained from releasing the water molecule into the bulk solvent. We computed the free energy of water released from the binding site for each hydration site using thermodynamic analysis of molecular dynamics (MD) simulations. Pharmacophores which are co-localized with hydration sites with estimated favorable contributions to the free energy of binding are selected to generate a reduced pharmacophore model. We constructed reduced pharmacophore models for three protein systems and demonstrated good enrichment quality combined with high efficiency. The reduction in pharmacophore model size reduces the required screening time by a factor of 200–500 compared to using all protein pharmacophore elements. We also describe a training process using a small set of known actives to reliably select the optimal set of criteria for pharmacophore selection for each protein system. PMID:22397751

Corrective Action Decision Document/Corrective Action Plan for Corrective Action Unit 573: Alpha Contaminated Sites Nevada National Security Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Patrick

CAU 573 comprises the following corrective action sites (CASs): • 05-23-02, GMX Alpha Contaminated Area • 05-45-01, Atmospheric Test Site - Hamilton These two CASs include the release at the Hamilton weapons-related tower test and a series of 29 atmospheric experiments conducted at GMX. The two CASs are located in two distinctly separate areas within Area 5. To facilitate site investigation and data quality objective (DQO) decisions, all identified releases (i.e., CAS components) were organized into study groups. The reporting of investigation results and the evaluation of DQO decisions are at the release level. The corrective action alternatives (CAAs) weremore » evaluated at the FFACO CAS level. The purpose of this CADD/CAP is to evaluate potential CAAs, provide the rationale for the selection of recommended CAAs, and provide the plan for implementation of the recommended CAA for CAU 573. Corrective action investigation (CAI) activities were performed from January 2015 through November 2015, as set forth in the CAU 573 Corrective Action Investigation Plan (CAIP). Analytes detected during the CAI were evaluated against appropriate final action levels (FALs) to identify the contaminants of concern. Assessment of the data generated from investigation activities conducted at CAU 573 revealed the following: • Radiological contamination within CAU 573 does not exceed the FALs (based on the Occasional Use Area exposure scenario). • Chemical contamination within CAU 573 does not exceed the FALs. • Potential source material—including lead plates, lead bricks, and lead-shielded cables—was removed during the investigation and requires no additional corrective action.« less

Sources of Radium Accumulation in Stream Sediments near Disposal Sites in Pennsylvania: Implications for Disposal of Conventional Oil and Gas Wastewater.

PubMed

Lauer, Nancy E; Warner, Nathaniel R; Vengosh, Avner

2018-02-06

In Pennsylvania, Appalachian oil and gas wastewaters (OGW) are permitted for release to surface waters after some treatment by centralized waste treatment (CWT) facilities. While this practice was largely discontinued in 2011 for unconventional Marcellus OGW at facilities permitted to release high salinity effluents, it continues for conventional OGW. This study aimed to evaluate the environmental implications of the policy allowing the disposal of conventional OGW. We collected stream sediments from three disposal sites receiving treated OGW between 2014 and 2017 and measured 228 Ra, 226 Ra, and their decay products, 228 Th and 210 Pb, respectively. We consistently found elevated activities of 228 Ra and 226 Ra in stream sediments in the vicinity of the outfall (total Ra = 90-25,000 Bq/kg) compared to upstream sediments (20-80 Bq/kg). In 2015 and 2017, 228 Th/ 228 Ra activity ratios in sediments from two disposal sites were relatively low (0.2-0.7), indicating that a portion of the Ra has accumulated in the sediments in recent (<3) years, when no unconventional Marcellus OGW was reportedly discharged. 228 Ra/ 226 Ra activity ratios were also higher than what would be expected solely from disposal of low 228 Ra/ 226 Ra Marcellus OGW. Based on these variations, we concluded that recent disposal of treated conventional OGW is the source of high Ra in stream sediments at CWT facility disposal sites. Consequently, policies pertaining to the disposal of only unconventional fluids are not adequate in preventing radioactive contamination in sediments at disposal sites, and the permission to release treated Ra-rich conventional OGW through CWT facilities should be reconsidered.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commericial power reactors operating during 1985. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 61 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 73 person-rem to a low of 0.011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 200 person-rem for the 110 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 5 /times/ 10/sup /minus/6/ mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1984. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 56 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 110 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 5 person-rem. The total population dose for all sites was estimated at 280 person-rem for the 100 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 6 x 10/sup -6/ mrem to a high of 0.04 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1986

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1986. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 66 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 kmmore » around each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 31 person-rem to a low of 0.0007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.7 person-rem. The total population dose for all sites was estimated at 110 person-rem for the 140 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 2 {times} 10{sup -6} mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. 12 refs.« less

Nanostructured lipid carriers: effect of solid phase fraction and distribution on the release of encapsulated materials.

PubMed

Dan, Nily

2014-11-25

Emulsions, solid lipid nanoparticles (SLN), and nanostructured lipid carriers (NLC) containing a mix of liquid and solid domains are of interest as encapsulation vehicles for hydrophobic compounds. Studies of the release rate from these particles yield contradictory results: Some find that increasing the fraction of solid phase increases the rate of release and others the opposite. In this paper we study the release of encapsulated materials from lipid-based nanoparticles using Monte Carlo simulations. We find that, quite surprisingly, the release rate is largely insensitive to the size of solid domains or the fraction of solid phase. However, the distribution of the domains significantly affects the rate of release: Solid domains located at the interface with the surrounding solution inhibit transport, while nanoparticles where the solid domains are concentrated in the center enhance it. The latter can lead to release rates in NLCs that are faster than in the equivalent emulsions. We conclude that controlling the release rate from NLCs requires the ability to determine the location and distribution of the solid phase, which may be achieved through choice of the surfactants stabilizing the particles, incorporation of nucleation sites, and/or the cooling rates and temperatures.

Light-stimulated cargo release from a core–shell structured nanocomposite for site-specific delivery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Yun; Ling, Li; Li, Xiaofang

This paper reported a core–shell structured site-specific delivery system with a light switch triggered by low energy light (λ=510 nm). Its core was composed of supermagnetic Fe{sub 3}O{sub 4} nanoparticles for magnetic guiding and targeting. Its outer shell consisted of mesoporous silica molecular sieve MCM-41 which offered highly ordered hexagonal tunnels for cargo capacity. A light switch N1-(4aH-cyclopenta[1,2-b:5,4-b′]dipyridin-5(5aH)-ylidene)benzene-1, 4-diamine (CBD) was covalently grafted into these hexagonal tunnels, serving as light stimuli acceptor with loading content of 1.1 μM/g. This composite was fully characterized and confirmed by SEM, TEM, XRD patterns, N{sub 2} adsorption/desorption, thermogravimetric analysis, IR, UV–vis absorption and emissionmore » spectra. Experimental data suggested that this composite had a core as wide as 150 nm and could be magnetically guided to specific sites. Its hexagonal tunnels were as long as 180 nm. Upon light stimuli of “on” and “off” states, controllable release was observed with short release time of ~900 s (90% capacity). - Graphical abstract: A core–shell structured site-specific delivery system with a light switch triggered by yellow light was constructed. Controllable release was observed with short release time of ~900 s (90% capacity). - Highlights: • A core–shell structured site-specific delivery system was constructed. • It consisted of Fe{sub 3}O{sub 4} core and MCM-41 shell grafted with light switch. • This delivery system was triggered by low energy light. • Controllable release was observed with short release time of ~900 s.« less

Simulation of Tracer Concentration Data in the Brush Creek Drainage Flow Using an Integrated Puff Model.

NASA Astrophysics Data System (ADS)

Rao, K. Shankar; Eckman, Richard M.; Hosker, Rayford P., Jr.

1989-07-01

During the 1984 ASCOT field study in Brush Creek Valley, two perfluorocarbon tracers were released into the nocturnal drainage flow at two different heights. The resulting surface concentrations were sampled at 90 sites, and vertical concentration profiles at 11 sites. These detailed tracer measurements provide a valuable dataset for developing and testing models of pollutant transport and dispersion in valleys.In this paper, we present the results of Gaussian puff model simulations of the tracer releases in Brush Creek Valley. The model was modified to account for the restricted lateral dispersion in the valley, and for the gross elevation differences between the release site and the receptors. The variable wind fields needed to transport the puffs were obtained by interpolation between wind profiles measured using tethered balloons at five along-valley sites. Direct turbulence measurements were used to estimate diffusion. Subsidence in the valley flow was included for elevated releases.Two test simulations-covering different nights, tracers, and release heights-were performed. The predicted hourly concentrations were compared with observations at 51 ground-level locations. At most sites, the predicted and observed concentrations agree within a factor of 2 to 6. For the elevated release simulation, the observed mean concentration is 40 pL/L, the predicted mean is 21 pL/L, the correlation coefficient between the observed and predicted concentrations is 0.24, and the index of agreement is 0.46. For the surface release simulation, the observed mean is 85 pL/L, and the predicted mean is 73 pL/L. The correlation coefficient is 0.23, and the index of agreement is 0.42. The results suggest that this modified puff model can be used as a practical tool for simulating pollutant transport and dispersion in deep valleys.

Gravity Field Solution Derived from Recent Releases of GOCE-Based Geopotential Models and Terrestrial Gravity Observations over The Kingdom of Saudi Arabia

NASA Astrophysics Data System (ADS)

Alothman, Abdulaziz; Elsaka, Basem

2015-03-01

The free air gravity anomalies over Saudi Arabia (KSA) has been estimated from the final releases of GOCE-based global geopotential models (GGMs) compared with the terrestrial gravity anomalies of 3554 sites. Two GGMs; EGM08 and Eigen-6C3 have been applied. The free-air anomalies from GOCE-based, ΔgGGM, have been calculated over the 3554 stations in the medium and short spectrum of gravity wavelength of d/o 100, …, 250 (with 10 step). The short spectrum has been compensated once from d/o 101, …, 251 to 2190 and 1949 using EGM08 and Eigen-6C3 (i.e. ΔgGGM), respectively. The very short component was determined using residual terrain modelling approach. Our findings show firstly that the EGM08 is more reliable than Eigen-6C3. Second, the GOCE-based GGMs provide similar results within the spectral wavelength band from d/o 100 to d/o 180. Beyond d/o 180 till d/o 250, we found that GOCE-based TIM model releases provide substantial improvements within the spectral band from d/o 220 to d/o 250 with respect to the DIR releases. Third, the TIM_r5 model provides the least standard deviations (st. dev.) in terms of gravity anomalies.

Addendum to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 452: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant Evenson

This document constitutes an addendum to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 452: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, April 1998 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additionalmore » information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the URs for CASs: • 25-25-09, Spill H940825C (from UST 25-3101-1) • 25-25-14, Spill H940314E (from UST 25-3102-3) • 25-25-15, Spill H941020E (from UST 25-3152-1) These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove these URs because contamination is not present at these sites above the risk-based FALs. Requirements for inspecting and maintaining these URs will be canceled, and the postings and signage at each site will be removed. Fencing and posting may be present at these sites that are unrelated to the FFACO URs such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at these sites.« less

Addendum 2 to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 454: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant Evenson

This document constitutes an addendum to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 454: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, April 1998 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additionalmore » information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the URs for CASs: • 12-25-08, Spill H950524F (from UST 12-B-1) • 12-25-10, Spill H950919A (from UST 12-COMM-1) These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove these URs because contamination is not present at these sites above the risk-based FALs. Requirements for inspecting and maintaining these URs will be canceled, and the postings and signage at each site will be removed. Fencing and posting may be present at these sites that are unrelated to the FFACO URs such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at these sites.« less

Humpback whales feed on hatchery-released juvenile salmon

PubMed Central

Straley, Janice M.; McPhee, Megan V.; Atkinson, Shannon; Reifenstuhl, Steve

2017-01-01

Humpback whales are remarkable for the behavioural plasticity of their feeding tactics and the diversity of their diets. Within the last decade at hatchery release sites in Southeast Alaska, humpback whales have begun exploiting juvenile salmon, a previously undocumented prey. The anthropogenic source of these salmon and their important contribution to local fisheries makes the emergence of humpback whale predation a concern for the Southeast Alaska economy. Here, we describe the frequency of observing humpback whales, examine the role of temporal and spatial variables affecting the probability of sighting humpback whales and describe prey capture behaviours at five hatchery release sites. We coordinated twice-daily 15 min observations during the spring release seasons 2010–2015. Using logistic regression, we determined that the probability of occurrence of humpback whales increased after releases began and decreased after releases concluded. The probability of whale occurrence varied among release sites but did not increase significantly over the 6 year study period. Whales were reported to be feeding on juvenile chum, Chinook and coho salmon, with photographic and video records of whales feeding on coho salmon. The ability to adapt to new prey sources may be key to sustaining their population in a changing ocean. PMID:28791145

Underground Nuclear Explosions and Release of Radioactive Noble Gases

NASA Astrophysics Data System (ADS)

Dubasov, Yuri V.

2010-05-01

Over a period in 1961-1990 496 underground nuclear tests and explosions of different purpose and in different rocks were conducted in the Soviet Union at Semipalatinsk and anovaya Zemlya Test Sites. A total of 340 underground nuclear tests were conducted at the Semipalatinsk Test Site. One hundred seventy-nine explosions (52.6%) among them were classified as these of complete containment, 145 explosions (42.6%) as explosions with weak release of radioactive noble gases (RNG), 12 explosions (3.5%) as explosions with nonstandard radiation situation, and four excavation explosions with ground ejection (1.1%). Thirty-nine nuclear tests had been conducted at the Novaya Zemlya Test Site; six of them - in shafts. In 14 tests (36%) there were no RNG release. Twenty-three tests have been accompanied by RNG release into the atmosphere without sedimental contamination. Nonstandard radiation situation occurred in two tests. In incomplete containment explosions both early-time RNG release (up to ~1 h) and late-time release from 1 to 28 h after the explosion were observed. Sometimes gas release took place for several days, and it occurred either through tunnel portal or epicentral zone, depending on atmospheric air temperature.

Humpback whales feed on hatchery-released juvenile salmon.

PubMed

Chenoweth, Ellen M; Straley, Janice M; McPhee, Megan V; Atkinson, Shannon; Reifenstuhl, Steve

2017-07-01

Humpback whales are remarkable for the behavioural plasticity of their feeding tactics and the diversity of their diets. Within the last decade at hatchery release sites in Southeast Alaska, humpback whales have begun exploiting juvenile salmon, a previously undocumented prey. The anthropogenic source of these salmon and their important contribution to local fisheries makes the emergence of humpback whale predation a concern for the Southeast Alaska economy. Here, we describe the frequency of observing humpback whales, examine the role of temporal and spatial variables affecting the probability of sighting humpback whales and describe prey capture behaviours at five hatchery release sites. We coordinated twice-daily 15 min observations during the spring release seasons 2010-2015. Using logistic regression, we determined that the probability of occurrence of humpback whales increased after releases began and decreased after releases concluded. The probability of whale occurrence varied among release sites but did not increase significantly over the 6 year study period. Whales were reported to be feeding on juvenile chum, Chinook and coho salmon, with photographic and video records of whales feeding on coho salmon. The ability to adapt to new prey sources may be key to sustaining their population in a changing ocean.

Use of a Fish Transportation Barge for Increasing Returns of Steelhead Imprinted for Homing, Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harmon, Jerrel R.

1989-08-01

The objective of this 7-year National Fisheries Service study, which began is 1982, was to determine if transporting juvenile steelhead (Oncorhynchus mykiss) by truck and barge from Dworshak National Fish Hatchery (NFH), on the Clearwater River, to a release site on the Columbia River below Bonneville Dam would result in increased returns of adults to the various fisheries and to the hatchery homing site. During 1982 and 1983, over 500,000 marked juvenile steelhead were serially released as controls from the hatchery or barged as test fish to below Bonneville Dam. Recoveries of marked adults to various recovery sites are complete.more » Fish released in 1983 showed a stronger homing ability and more rapid upstream migration than test fish released in 1982. Most adults from both control and test releases in 1983 and control releases in 1982 migrated a considerable distance upstream and overwintered in the Snake and Clearwater Rivers--behavior similar to Clearwater River fish previously transported from Lower Granite Dam. In contrast, many of the adults from test releases in 1982 failed to migrate upstream during the fall, overwintered in the Columbia River, and migrated upstream the following spring. Survival of control fish released at Dworshak NFH in late April 1982 was substantially higher than survival of those released in mid-May. Survival and homing of control fish released in late April and early May 1983 were over 10 times that for fish released in late May. Return of adults from normal hatchery releases in 1982 was the highest ever observed at Dworshak NFH.« less

Emulsion-based encapsulation and delivery of nanoparticles for the controlled release of alkalinity within the subsurface environment

NASA Astrophysics Data System (ADS)

Ramsburg, C. A.; Muller, K.; Gill, J.

2012-12-01

Many current approaches to managing groundwater contamination rely on further advances in amendment delivery in order to initiate and sustain contaminant degradation or immobilization. In fact, limited or ineffective delivery is often cited when treatment objectives are not attained. Emulsions, specifically oil-in-water emulsions, have demonstrated potential to aid delivery of remediation amendments. Emulsions also afford opportunities to control the release of active ingredients encapsulated within the droplets. Our research is currently focused on the controlled release of nanoparticle-based buffering agents using oil-in-water emulsions. This interest is motivated by the fact that chemical and biological processes employed for the remediation and stewardship of contaminated sites often necessitate control of pH during treatment and, in some cases, long thereafter. Alkalinity-release nanoparticles (e.g., CaCO3, MgO) were suspended within soybean oil and subsequently encapsulated by through the creation of oil-in-water emulsions. These oil-in-water emulsions are designed to have physical properties which are favorable for subsurface delivery (nominal properties: 1 g/mL density; 10 cP viscosity; and 1.5 μm droplet diameter). Buffer capacity titrations suggest that MgO particles are moderately more accessible within the oil phase and nearly twice as effective (on a per mass basis) at releasing alkalinity (as compared to the CaCO3 particles). Results from experiments designed to assess the release kinetics suggest that a linear driving force model is capable of describing the release process and mass transfer coefficients are constant through the reactive life of the emulsion. The release kinetics in emulsions containing MgO particles were found to be three orders of magnitude faster than those quantified for emulsions containing CaCO3. The slower release kinetics of the emulsions containing CaCO3 particles may prove beneficial when considering pH control at sites where acid fluxes are lower. The ability of emulsions to sustain alkalinity release within porous media was preliminarily examined using a series of 1-D column experiments. Emulsions were introduced for 2 pore volumes in a medium sand at Darcy velocities of approximately 0.8 cm/hr. Following the emulsion pulse, a pH 4 solution (adjusted with HCl) was introduced into the column and the effluent was monitored for pH, oil content, and droplet size distributions. All un-retained emulsion (~20% wt. was retained) was flushed from the column within approximately 2 pore volumes of terminating the emulsion pulse. The effluent pH at quasi-steady state and the reactive life of the emulsion depended on the retention characteristics, as well as the type and loading of nanoparticles employed within the emulsion. For the scenarios considered here, quasi-steady effluent pHs were observed to be between 6.5 and 10, and reactive lifetimes (i.e., the number of pore volumes for which the retained emulsion resulted in the effluent pH exceeding that of the influent) were between 15 and 100 pore volumes. These results demonstrate the ability of the emulsion to offer longer-term release and highlight the ability to tune the alkalinity release rate to match site characteristics by adjusting the emulsion content. Current research is directed toward evaluation release properties in heterogeneous aquifer cell experiments.

Observed form and action of the magnetic energy release in flares

NASA Technical Reports Server (NTRS)

Machado, Marcos E.; Moore, Ronald L.

1986-01-01

The observable spatio-temporal characteristics of the energy release in flares and their association with the magnetic environment and tracers of field dynamics are reviewed. The observations indicate that impulsive phase manifestations, like particle acceleration, may be related to the formation of neutral sheets at the interface between interacting bipoles, but that the site for the bulk of the energy release is within closed loops rather than at the interaction site.

Impairment of Release Site Clearance within the Active Zone by Reduced SCAMP5 Expression Causes Short-Term Depression of Synaptic Release.

PubMed

Park, Daehun; Lee, Unghwi; Cho, Eunji; Zhao, Haiyan; Kim, Jung Ah; Lee, Byoung Ju; Regan, Philip; Ho, Won-Kyung; Cho, Kwangwook; Chang, Sunghoe

2018-03-20

Despite being a highly enriched synaptic vesicle (SV) protein and a candidate gene for autism, the physiological function of SCAMP5 remains mostly enigmatic. Here, using optical imaging and electrophysiological experiments, we demonstrate that SCAMP5 plays a critical role in release site clearance at the active zone. Truncation analysis revealed that the 2/3 loop domain of SCAMP5 directly interacts with adaptor protein 2, and this interaction is critical for its role in release site clearance. Knockdown (KD) of SCAMP5 exhibited pronounced synaptic depression accompanied by a slower recovery of the SV pool. Moreover, it induced a strong frequency-dependent short-term depression of synaptic release, even under the condition of sufficient release-ready SVs. Super-resolution microscopy further proved the defects in SV protein clearance induced by KD. Thus, reduced expression of SCAMP5 may impair the efficiency of SV clearance at the active zone, and this might relate to the synaptic dysfunction observed in autism. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Mark-release-recapture studies with Aedes dorsalis (Diptera: Culicidae) in coastal northern California.

PubMed

Kramer, V L; Carper, E R; Beesley, C; Reisen, W K

1995-05-01

Two mark-release-recapture studies were conducted along the Sacramento-San Joaquin River Delta in northern California to describe the population ecology and dispersal pattern of Aedes dorsalis (Meigen). Immature Ae. dorsalis were collected from saline tidal marshes, reared to adults, marked, and released. Recapture grids during the July and September studies were within 8.0 and 2.4 km of the release sites, and recapture rates were 0.1 and 1.2%, respectively. The longest recorded flight was 5.8 km, and mosquitoes were recaptured up to 15 d after release. In September, 84% of the marked mosquitoes were recaptured within 2.0 km of the release site, and the mean dispersal distance was 1.9 km. Marked mosquitoes flew predominantly downwind to the east. There was no evidence that Ae. dorsalis traversed the 1.6-km-wide river from Contra Costa to Solano County. Temporal and spatial recapture patterns indicated a possible short-range migration pattern from oviposition sites to upland host-seeking areas. Changes in the recapture rate with cohort age delineated a 7-d gonotrophic cycle during September.

Fabrication and Release Behavior of Microcapsules with Double-Layered Shell Containing Clove Oil for Antibacterial Applications.

PubMed

Chong, Yong-Bing; Zhang, He; Yue, Chee Yoon; Yang, Jinglei

2018-05-09

In this study, double-layer polyurethane/poly(urea-formaldehyde) (PU/PUF) shell microcapsules containing clove oil with antibacterial properties were successfully synthesized via in situ and interfacial polymerization reactions in an oil-in-water emulsion. The morphology, core-shell structure, and composition of the microcapsules were investigated systematically. Additionally, the release behaviors of microcapsules synthesized under different reaction parameters were studied. It was found that the release rate of clove oil can be controlled by tuning the amount of PU reactants and the length of PUF deposition time. The release profile fitted well against the Baker-Lonsdale model, which indicates diffusion as the primary release mechanism. Experimental results based on the ASTM E2315 time kill test revealed that the fabricated microcapsules have great antibacterial activities against the marine bacteria Vibrio coralliilyticus, Escherichia coli, Exiguobacterium aestuarii, and marine biofilm-forming bacteria isolated from the on-site contaminated samples, showing their great potential as an eco-friendly solution to replace existing toxic antifouling agent.

HTO and OBT activity concentrations in soil at the historical atmospheric HT release site (Chalk River Laboratories).

PubMed

Kim, S B; Bredlaw, M; Korolevych, V Y

2012-01-01

Tritium is routinely released by the Chalk River Laboratories (CRL) nuclear facilities. Three International HT release experiments have been conducted at the CRL site in the past. The site has not been disturbed since the last historical atmospheric testing in 1994 and presents an opportunity to assess the retention of tritium in soil. This study is devoted to the measurement of HTO and OBT activity concentration profiles in the subsurface 25 cm of soil. In terms of soil HTO, there is no evidence from the past HT release experiments that HTO was retained. The HTO activity concentration in the soil pore water appears similar to concentrations found in background areas in Ontario. In contrast, OBT activity concentrations in soil at the same site were significantly higher than HTO activity concentrations in soil. Elevated OBT appears to reside in the top layer of the soil (0-5 cm). In addition, OBT activity concentrations in the top soil layer did not fluctuate much with season, again, quite in contrast with soil HTO. This result suggests that OBT activity concentrations retained the signature of the historical tritium releases. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

The potential of magneto-electric nanocarriers for drug delivery

PubMed Central

Kaushik, Ajeet; Jayant, Rahul Dev; Sagar, Vidya; Nair, Madhavan

2015-01-01

Introduction The development and design of personalized nanomedicine for better health quality is receiving great attention. In order to deliver and release a therapeutic concentration at the target site, novel nanocarriers (NCs) were designed, for example, magneto-electric (ME) which possess ideal properties of high drug loading, site-specificity and precise on-demand controlled drug delivery. Areas covered This review explores the potential of ME-NCs for on-demand and site-specific drug delivery and release for personalized therapeutics. The main features including effect of magnetism, improvement in drug loading, drug transport across blood-brain barriers and on-demand controlled release are also discussed. The future directions and possible impacts on upcoming nanomedicine are highlighted. Expert opinion Numerous reports suggest that there is an urgent need to explore novel NC formulations for safe and targeted drug delivery and release at specific disease sites. The challenges of formulation lie in the development of NCs that improve biocompatibility and surface modifications for optimum drug loading/preservation/transmigration and tailoring of electrical–magnetic properties for on-demand drug release. Thus, the development of novel NCs is anticipated to overcome the problems of targeted delivery of therapeutic agents with desired precision that may lead to better patient compliance. PMID:24986772

The potential of magneto-electric nanocarriers for drug delivery.

PubMed

Kaushik, Ajeet; Jayant, Rahul Dev; Sagar, Vidya; Nair, Madhavan

2014-10-01

The development and design of personalized nanomedicine for better health quality is receiving great attention. In order to deliver and release a therapeutic concentration at the target site, novel nanocarriers (NCs) were designed, for example, magneto-electric (ME) which possess ideal properties of high drug loading, site-specificity and precise on-demand controlled drug delivery. This review explores the potential of ME-NCs for on-demand and site-specific drug delivery and release for personalized therapeutics. The main features including effect of magnetism, improvement in drug loading, drug transport across blood-brain barriers and on-demand controlled release are also discussed. The future directions and possible impacts on upcoming nanomedicine are highlighted. Numerous reports suggest that there is an urgent need to explore novel NC formulations for safe and targeted drug delivery and release at specific disease sites. The challenges of formulation lie in the development of NCs that improve biocompatibility and surface modifications for optimum drug loading/preservation/transmigration and tailoring of electrical-magnetic properties for on-demand drug release. Thus, the development of novel NCs is anticipated to overcome the problems of targeted delivery of therapeutic agents with desired precision that may lead to better patient compliance.

Formulation and evaluation of controlled release antibiotic biodegradable implants for post operative site delivery.

PubMed

Mathur, Vijay; Mudnaik, Rajesh; Barde, Laxmikant; Roy, Arghya; Shivhare, Umesh; Bhusari, Kishore

2010-03-01

Biodegradable implants of ciprofloxacin hydrochloride for post operative site delivery were prepared using glyceryl monostearate and different concentrations of polyethylene glycol (PEG 6000), glycerol and Tween 80 as erosion enhancers by compression and molding technique. Formulations were subjected to in vitro drug release by the USP dissolution method, while promising formulations were subjected to in vitro drug release by the agar gel method and also to stability studies. It was observed that glyceryl monostearate formed hydrophobic matrix and delayed the drug delivery. Antibiotic release profile was controlled by using different combinations of erosion enhancers. The formulation prepared by the compression method showed more delayed release compared to formulations prepared by the molding method.

Revisiting synaptic vesicle pool localization in the Drosophila neuromuscular junction

PubMed Central

Denker, Annette; Kröhnert, Katharina; Rizzoli, Silvio O

2009-01-01

The synaptic vesicles are organized in distinct populations or ‘pools’: the readily releasable pool (the first vesicles released upon stimulation), the recycling pool (which maintains release under moderate stimulation) and the reserve pool (which is called into action only upon strong, often unphysiological stimulation). A major question in the field is whether the pools consist of biochemically different vesicles or whether the pool tag is a spatial one (with the recycling vesicles found next to the release sites, and the reserve ones farther away). A strong and stable spatial segregation has been proposed in the last decade in the Drosophila larval neuromuscular junction – albeit based solely on light microscopy experiments. We have tested here this hypothesis using electron microscopy (EM) photoconversion. We found the recycling and reserve pools to be thoroughly intermixed at the EM level, indicating that spatial location is irrelevant for the functional properties of the vesicle. PMID:19403600

Drupal Done Right

ERIC Educational Resources Information Center

Coombs, Karen

2009-01-01

Drupal is a PHP-and MySQL-based system for managing web sites, developed in 2000 and released in 2001 under the open GNU General Public License (GPL). It is modular, extensible, and scalable. In recent years, Drupal has gained a huge following within libraries as a content management system (CMS). Probably the best-known extension of Drupal in the…

MODELS AND METHODS FOR PETROLEUM HYDROCARBON RISK ASSESSMENT: ONSITE, LUSTRISK, AND HSSM

EPA Science Inventory

U.S. EPA has developed three tiers of models for analysis of fuel releases from underground storage tank (UST) systems: 1) OnSite; 2) LUSTRisk, and 3) the Hydrocarbon Spill Screening Model (HSSM). The tiered approach to modeling allows users to select a model based upon the amoun...

PKM2 released by neutrophils at wound site facilitates early wound healing by promoting angiogenesis.

PubMed

Zhang, Yinwei; Li, Liangwei; Liu, Yuan; Liu, Zhi-Ren

2016-03-01

Neutrophils infiltration/activation following wound induction marks the early inflammatory response in wound repair. However, the role of the infiltrated/activated neutrophils in tissue regeneration/proliferation during wound repair is not well understood. Here, we report that infiltrated/activated neutrophils at wound site release pyruvate kinase M2 (PKM2) by its secretive mechanisms during early stages of wound repair. The released extracellular PKM2 facilitates early wound healing by promoting angiogenesis at wound site. Our studies reveal a new and important molecular linker between the early inflammatory response and proliferation phase in tissue repair process. © 2016 by the Wound Healing Society.

Developing Health-Based Pre-Planning Clearance Goals for Airport Remediation Following Chemical Terrorist Attack: Introduction and Key Assessment Considerations

PubMed Central

Watson, Annetta; Hall, Linda; Raber, Ellen; Hauschild, Veronique D.; Dolislager, Fredrick; Love, Adam H.; Hanna, M. Leslie

2011-01-01

In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility reuse and re-entry could require hours to multiple days. While restoration timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical terrorist release. What follows is the first of a two-part analysis identifying key considerations, critical information, and decision criteria to facilitate post-attack and post-decontamination consequence management activities. A conceptual site model and human health-based exposure guidelines are developed and reported as an aid to site-specific pre-planning in the current absence of U.S. state or Federal values designated as compound-specific remediation or re-entry concentrations, and to safely expedite facility recovery to full operational status. Chemicals of concern include chemical warfare nerve and vesicant agents and the toxic industrial compounds phosgene, hydrogen cyanide, and cyanogen chloride. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination. PMID:21390292

Developing Health-Based Pre-Planning Clearance Goals for Airport Remediation Following Chemical Terrorist Attack: Introduction and Key Assessment Considerations.

PubMed

Watson, Annetta; Hall, Linda; Raber, Ellen; Hauschild, Veronique D; Dolislager, Fredrick; Love, Adam H; Hanna, M Leslie

2011-02-13

In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility reuse and re-entry could require hours to multiple days. While restoration timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical terrorist release. What follows is the first of a two-part analysis identifying key considerations, critical information, and decision criteria to facilitate post-attack and post-decontamination consequence management activities. A conceptual site model and human health-based exposure guidelines are developed and reported as an aid to site-specific pre-planning in the current absence of U.S. state or Federal values designated as compound-specific remediation or re-entry concentrations, and to safely expedite facility recovery to full operational status. Chemicals of concern include chemical warfare nerve and vesicant agents and the toxic industrial compounds phosgene, hydrogen cyanide, and cyanogen chloride. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination.

Developing health-based pre-planning clearance goals for airport remediation following chemical terrorist attack: Introduction and key assessment considerations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, Annetta Paule; Raber, Ellen; Dolislager, Frederick

2011-01-01

In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility re-use and re-entry could require hours to multiple days. While restoration timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical terrorist release. What follows is the first of a two-part analysis identifying key considerations, critical information, and decision criteria to facilitate post-attack and post-decontamination consequence management activities. A conceptual site model and human health-based exposure guidelines are developed and reported as an aid to site-specific pre-planningmore » in the current absence of U.S. state or Federal values designated as compound-specific remediation or re-entry concentrations, and to safely expedite facility recovery to full operational status. Chemicals of concern include chemical warfare nerve and vesicant agents and the toxic industrial compounds phosgene, hydrogen cyanide, and cyanogen chloride. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination.« less

Transport direction determines the kinetics of substrate transport by the glutamate transporter EAAC1

PubMed Central

Zhang, Zhou; Tao, Zhen; Gameiro, Armanda; Barcelona, Stephanie; Braams, Simona; Rauen, Thomas; Grewer, Christof

2007-01-01

Glutamate transport by the excitatory amino acid carrier EAAC1 is known to be reversible. Thus, glutamate can either be taken up into cells, or it can be released from cells through reverse transport, depending on the electrochemical gradient of the co- and countertransported ions. However, it is unknown how fast and by which reverse transport mechanism glutamate can be released from cells. Here, we determined the steady- and pre-steady-state kinetics of reverse glutamate transport with submillisecond time resolution. First, our results suggest that glutamate and Na+ dissociate from their cytoplasmic binding sites sequentially, with glutamate dissociating first, followed by the three cotransported Na+ ions. Second, the kinetics of glutamate transport depend strongly on transport direction, with reverse transport being faster but less voltage-dependent than forward transport. Third, electrogenicity is distributed over several reverse transport steps, including intracellular Na+ binding, reverse translocation, and reverse relocation of the K+-bound EAAC1. We propose a kinetic model, which is based on a “first-in-first-out” mechanism, suggesting that glutamate association, with its extracellular binding site as well as dissociation from its intracellular binding site, precedes association and dissociation of at least one Na+ ion. Our model can be used to predict rates of glutamate release from neurons under physiological and pathophysiological conditions. PMID:17991780

Cell-free protein synthesis from genomically recoded bacteria enables multisite incorporation of noncanonical amino acids.

PubMed

Martin, Rey W; Des Soye, Benjamin J; Kwon, Yong-Chan; Kay, Jennifer; Davis, Roderick G; Thomas, Paul M; Majewska, Natalia I; Chen, Cindy X; Marcum, Ryan D; Weiss, Mary Grace; Stoddart, Ashleigh E; Amiram, Miriam; Ranji Charna, Arnaz K; Patel, Jaymin R; Isaacs, Farren J; Kelleher, Neil L; Hong, Seok Hoon; Jewett, Michael C

2018-03-23

Cell-free protein synthesis has emerged as a powerful approach for expanding the range of genetically encoded chemistry into proteins. Unfortunately, efforts to site-specifically incorporate multiple non-canonical amino acids into proteins using crude extract-based cell-free systems have been limited by release factor 1 competition. Here we address this limitation by establishing a bacterial cell-free protein synthesis platform based on genomically recoded Escherichia coli lacking release factor 1. This platform was developed by exploiting multiplex genome engineering to enhance extract performance by functionally inactivating negative effectors. Our most productive cell extracts enabled synthesis of 1,780 ± 30 mg/L superfolder green fluorescent protein. Using an optimized platform, we demonstrated the ability to introduce 40 identical p-acetyl-L-phenylalanine residues site specifically into an elastin-like polypeptide with high accuracy of incorporation ( ≥ 98%) and yield (96 ± 3 mg/L). We expect this cell-free platform to facilitate fundamental understanding and enable manufacturing paradigms for proteins with new and diverse chemistries.

Like mother, like daughter: inheritance of nest-site location in snakes.

PubMed

Brown, Gregory P; Shine, Richard

2007-04-22

A trait can be passed from parents to offspring even if it has no genetic basis. For example, if daughters return to reproduce at the same sites where they were hatched themselves, nest-site location is consistent within matrilineages. Most cases of natal homing (nest-site philopatry) across generations have been inferred from molecular evidence rather than directly demonstrated, and involve species with low dispersal abilities. However, some animals disperse long distances but then return to their own place of birth to reproduce, based on cues imprinted early in their own development. Our field studies on tropical natricine snakes (Tropidonophis mairii, Colubridae) show that when they are ready to nest, females return to the sites where their mothers were captured pre-nesting, and where they themselves were released as hatchlings.

Closure Report for Corrective Action Unit 568: Area 3 Plutonium Dispersion Sites Nevada National Security Site, Nevada, Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Patrick

The purpose of this CR is to provide documentation and justification that no further corrective action is needed for the closure of CAU 568 based on the implementation of corrective actions. This includes a description of closure activities that were performed and an evaluation of the verification data. The CAP (NNSA/NFO, 2016a) and ROTC-1 (NNSA/NFO, 2016c) provide information relating to the selection of CAAs and the reasoning behind their selection. The CADD (NNSA/NFO, 2015) identifies the release sites that require additional corrective action and presents information supporting the selection of CAAs.

Assessment of radiocarbon in the Savannah River Site Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlton, W.H.; Evans, A.G.; Murphy, C.E. Jr.

1993-03-01

This report is a radiological assessment of [sup 14]C releases from the Savannah River Site. During the operation of five production reactors [sup 14]C has been produced at SRS. Approximately 3000 curies have been released to the atmosphere but there are no recorded releases to surface waters. Once released, the [sup 14]C joins the carbon cycle and a portion enters the food chain. The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by a dose of 1.1 mrem, compared with a dose of 12,960 mrem from non-SRS sources during the same period of time.more » Releases of [sup 14]C have resulted in a negligible risk to the environment and the population it supports.« less

Assessment of radiocarbon in the Savannah River Site Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlton, W.H.; Evans, A.G.; Murphy, C.E. Jr.

1993-03-01

This report is a radiological assessment of {sup 14}C releases from the Savannah River Site. During the operation of five production reactors {sup 14}C has been produced at SRS. Approximately 3000 curies have been released to the atmosphere but there are no recorded releases to surface waters. Once released, the {sup 14}C joins the carbon cycle and a portion enters the food chain. The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by a dose of 1.1 mrem, compared with a dose of 12,960 mrem from non-SRS sources during the same period of time.more » Releases of {sup 14}C have resulted in a negligible risk to the environment and the population it supports.« less

Phorid Flies in Alabama: A tale of two species

USDA-ARS?s Scientific Manuscript database

Two species of phorid fly have been released at 11 sites in Alabama and have been recovered from 9 sites. Pseudacteon tricuspis Borgmeier (Diptera: Phoridae) was released in South Alabama in populations of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), and Pseudacteon...

40 CFR 280.62 - Initial abatement measures and site check.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Initial abatement measures and site check. 280.62 Section 280.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... to the environment; (2) Visually inspect any aboveground releases or exposed belowground releases and...

Corrective Action Investigation Plan for Corrective Action Unit 413: Clean Slate II Plutonium Dispersion (TTR) Tonopah Test Range, Nevada, Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Patrick; Burmeister, Mark; Gallo, Patricia

Corrective Action Unit (CAU) 413 is located on the Tonopah Test Range, which is approximately 130 miles northwest of Las Vegas, Nevada, and approximately 40 miles southeast of Tonopah, Nevada. The CAU 413 site consists of the release of radionuclides to the surface and shallow subsurface from the conduct of the Clean Slate II (CSII) storage–transportation test conducted on May 31, 1963. CAU 413 includes one corrective action site (CAS), TA-23-02CS (Pu Contaminated Soil). The known releases at CAU 413 are the result of the atmospheric deposition of contamination from the 1963 CSII test. The CSII test was a non-nuclearmore » detonation of a nuclear device located inside a reinforced concrete bunker covered with 2 feet of soil. This test dispersed radionuclides, primarily plutonium, on the ground surface. The presence and nature of contamination at CAU 413 will be evaluated based on information collected from a corrective action investigation (CAI). The investigation is based on the data quality objectives (DQOs) developed on June 17, 2015, by representatives of the Nevada Division of Environmental Protection; the U.S. Air Force; and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 413. The CAI will include radiological surveys, geophysical surveys, collection and analyses of soil samples, and assessment of investigation results. The collection of soil samples will be accomplished using both probabilistic and judgmental sampling approaches. To facilitate site investigation and the evaluation of DQO decisions, the releases at CAU 413 have been divided into seven study groups.« less

Hanford waste-form release and sediment interaction: A status report with rationale and recommendations for additional studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serne, R.J.; Wood, M.I.

1990-05-01

This report documents the currently available geochemical data base for release and retardation for actual Hanford Site materials (wastes and/or sediments). The report also recommends specific laboratory tests and presents the rationale for the recommendations. The purpose of this document is threefold: to summarize currently available information, to provide a strategy for generating additional data, and to provide recommendations on specific data collection methods and tests matrices. This report outlines a data collection approach that relies on feedback from performance analyses to ascertain when adequate data have been collected. The data collection scheme emphasizes laboratory testing based on empiricism. 196more » refs., 4 figs., 36 tabs.« less

Global radioxenon emission inventory based on nuclear power reactor reports.

PubMed

Kalinowski, Martin B; Tuma, Matthias P

2009-01-01

Atmospheric radioactivity is monitored for the verification of the Comprehensive Nuclear-Test-Ban Treaty, with xenon isotopes 131mXe, 133Xe, 133mXe and 135Xe serving as important indicators of nuclear explosions. The treaty-relevant interpretation of atmospheric concentrations of radioxenon is enhanced by quantifying radioxenon emissions released from civilian facilities. This paper presents the first global radioxenon emission inventory for nuclear power plants, based on North American and European emission reports for the years 1995-2005. Estimations were made for all power plant sites for which emission data were unavailable. According to this inventory, a total of 1.3PBq of radioxenon isotopes are released by nuclear power plants as continuous or pulsed emissions in a generic year.

Development of a Sustainable Release System for a Ranibizumab Biosimilar Using Poly(lactic-co-glycolic acid) Biodegradable Polymer-Based Microparticles as a Platform.

PubMed

Tanetsugu, Yusuke; Tagami, Tatsuaki; Terukina, Takayuki; Ogawa, Takaya; Ohta, Masato; Ozeki, Tetsuya

2017-01-01

Ranibizumab is a humanized monoclonal antibody fragment against vascular endothelial growth factor (VEGF)-A and is widely used to treat age-related macular degeneration (AMD) caused by angiogenesis. Ranibizumab has a short half-life in the eye due to its low molecular weight and susceptibility to proteolysis. Monthly intravitreal injection of a large amount of ranibizumab formulation is a burden for both patients and medical staff. We therefore sought to develop a sustainable release system for treating the eye with ranibizumab using a drug carrier. A ranibizumab biosimilar (RB) was incorporated into microparticles of poly(lactic-co-glycolic acid) (PLGA) biodegradable polymer. Ranibizumab was sustainably released from PLGA microparticles (80+% after 3 weeks). Assay of tube formation by endothelial cells indicated that RB released from PLGA microparticles inhibited VEGF-induced tube formation and this tendency was confirmed by a cell proliferation assay. These results indicate that RB-loaded PLGA microparticles are useful for sustainable RB release and suggest the utility of intraocular sustainable release systems for delivering RB site-specifically to AMD patients.

Population dose commitments due to radioactive releases from Nuclear-Power-Plant Sites in 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.; Peloquin, R.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1979. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving variousmore » average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 1300 person-rem to a low of 0.0002 person-rem with an arithmetic mean of 38 person-rem. The total population dose for all sites was estimated at 1800 person-rem for the 94 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 2 x 10/sup -6/ mrem to a high of 0.7 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Population Dose Commitments Due to Radioactive Releases from Nuclear Power Plant Sites in 1977

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D. A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1977. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ, Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving variousmore » average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 220 person-rem to a low of 0.003 person-rem with an arithmetic mean of 16 person-rem. The total population dose for all sites was estimated at 700 person-rem for the 92 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 2 x 10{sup -5} mrem to a high of 0.1 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Demonstration of an In-Situ Friction-Sound Probe for Mapping Particle Size at Contaminated Sediment Sites

DTIC Science & Technology

2013-09-01

management practices resulting in the release of contaminants to soil , sediment, and groundwater in coastal environments. At contaminated sediment sites it...the release of contaminants to soil , sediment, and groundwater in coastal environments. Areas of potential concern at these sites are identified by...study will acquire additional soil and groundwater data necessary to satisfactorily evaluate remedial technologies and develop cleanup goals supporting

Mapping polycyclic aromatic hydrocarbon and total toxicity equivalent soil concentrations by visible and near-infrared spectroscopy.

PubMed

Okparanma, Reuben N; Coulon, Frederic; Mayr, Thomas; Mouazen, Abdul M

2014-09-01

In this study, we used data from spectroscopic models based on visible and near-infrared (vis-NIR; 350-2500 nm) diffuse reflectance spectroscopy to develop soil maps of polycyclic aromatic hydrocarbons (PAHs) and total toxicity equivalent concentrations (TTEC) of the PAH mixture. The TTEC maps were then used for hazard assessment of three petroleum release sites in the Niger Delta province of Nigeria (5.317°N, 6.467°E). As the paired t-test revealed, there were non-significant (p > 0.05) differences between soil maps of PAH and TTEC developed with chemically measured and vis-NIR-predicted data. Comparison maps of PAH showed a slight to moderate agreement between measured and predicted data (Kappa coefficient = 0.19-0.56). Using proposed generic assessment criteria, hazard assessment showed that the degree of action for site-specific risk assessment and/or remediation is similar for both measurement methods. This demonstrates that the vis-NIR method may be useful for monitoring hydrocarbon contamination in a petroleum release site. Copyright © 2014 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brownlow, D.T.; Escude, S.; Johanneson, O.H.

The 1500 Area at Kelly Air Force Base (AFB) was the site of a subsurface release of approximately 1,000 gallons of JP-4 jet fuel. Preliminary studies found evidence of hydrocarbon contamination extending from 10 feet below ground surface (bgs) down to the shallow water table, at 20 to 25 feet bgs. In June of 1993, Kelly AFB authorized the installation and evaluation of a bioventing system at this site to aid in the cleanup of the hydrocarbon contaminated soils. The purpose of the bioventing system is to aerate subsurface soils within and immediately surrounding the release area, in order tomore » stimulate in-situ biological activity and enhance the natural bioremediation capacity of the soil. Augmenting oxygen to the indigenous soil microorganisms promotes the aerobic metabolism of fuel hydrocarbons in the soil. In vadose zone soils exhibiting relatively good permeability, bioventing has proven to be a highly cost effective remediation technology for treating fuel contaminated soils. In November, 1993, a Start-Up Test program consisting of an In-Situ Respiration Test (ISRT) and an Air Permeability Test was performed at the 1500 Area Spill Site.« less

Addendum to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 454: Historical Undrground Storage Tank Release Sites, Nevada Test Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynn Kidman

This document constitutes an addendum to the April 1998, Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 454: Historical Underground Storage Tank Release Sites as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modificationmore » document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the UR for CAS 12-25-09, Spill 960722-02 (from UST 12-B-3). This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the FFACO UR such as for radiological control purposes as required by the NV/YMP Radiological Control Manual (NNSA/NSO, 2004f). This modification will not affect or modify any non-FFACO requirements for fencing, posting, or monitoring at this site.« less

Combining tracer flux ratio methodology with low-flying aircraft measurements to estimate dairy farm CH4 emissions

NASA Astrophysics Data System (ADS)

Daube, C.; Conley, S.; Faloona, I. C.; Yacovitch, T. I.; Roscioli, J. R.; Morris, M.; Curry, J.; Arndt, C.; Herndon, S. C.

2017-12-01

Livestock activity, enteric fermentation of feed and anaerobic digestion of waste, contributes significantly to the methane budget of the United States (EPA, 2016). Studies question the reported magnitude of these methane sources (Miller et. al., 2013), calling for more detailed research of agricultural animals (Hristov, 2014). Tracer flux ratio is an attractive experimental method to bring to this problem because it does not rely on estimates of atmospheric dispersion. Collection of data occurred during one week at two dairy farms in central California (June, 2016). Each farm varied in size, layout, head count, and general operation. The tracer flux ratio method involves releasing ethane on-site with a known flow rate to serve as a tracer gas. Downwind mixed enhancements in ethane (from the tracer) and methane (from the dairy) were measured, and their ratio used to infer the unknown methane emission rate from the farm. An instrumented van drove transects downwind of each farm on public roads while tracer gases were released on-site, employing the tracer flux ratio methodology to assess simultaneous methane and tracer gas plumes. Flying circles around each farm, a small instrumented aircraft made measurements to perform a mass balance evaluation of methane gas. In the course of these two different methane quantification techniques, we were able to validate yet a third method: tracer flux ratio measured via aircraft. Ground-based tracer release rates were applied to the aircraft-observed methane-to-ethane ratios, yielding whole-site methane emission rates. Never before has the tracer flux ratio method been executed with aircraft measurements. Estimates from this new application closely resemble results from the standard ground-based technique to within their respective uncertainties. Incorporating this new dimension to the tracer flux ratio methodology provides additional context for local plume dynamics and validation of both ground and flight-based data.

Corrective Action Decision Document for Corrective Action Unit 340: Pesticide Release sites, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

DOE /NV

This Corrective Action Decision Document has been prepared for Corrective Action Unit 340, the NTS Pesticide Release Sites, in accordance with the Federal Facility Agreement and Consent Order of 1996 (FFACO, 1996). Corrective Action Unit 340 is located at the Nevada Test Site, Nevada, and is comprised of the following Corrective Action Sites: 23-21-01, Area 23 Quonset Hut 800 Pesticide Release Ditch; 23-18-03, Area 23 Skid Huts Pesticide Storage; and 15-18-02, Area 15 Quonset Hut 15-11 Pesticide Storage. The purpose of this Corrective Action Decision Document is to identify and provide a rationale for the selection of a recommended correctivemore » action alternative for each Corrective Action Site. The scope of this Corrective Action Decision Document consists of the following tasks: Develop corrective action objectives; Identify corrective action alternative screening criteria; Develop corrective action alternatives; Perform detailed and comparative evaluations of the corrective action alternatives in relation to the corrective action objectives and screening criteria; and Recommend and justify a preferred corrective action alternative for each Corrective Action Site.« less

Use of Electrical Conductivity Logging to Characterize the Geological Context of Releases at UST Sites

EPA Science Inventory

Risk is the combination of hazard and exposure. Risk characterization at UST release sites has traditionally emphasized hazard (presence of residual fuel) with little attention to exposure. Exposure characterization often limited to a one-dimensional model such as the RBCA equa...

Assessment of the Incentives Created by Public Disclosure of Off-Site Consequence Analysis Information for Reduction in the Risk of Accidental Releases

EPA Pesticide Factsheets

The off-site consequence analysis (OCA) evaluates the potential for worst-case and alternative accidental release scenarios to harm the public and environment around the facility. Public disclosure would likely reduce the number/severity of incidents.

Redox-sensitive nanoparticles based on 4-aminothiophenol-carboxymethyl inulin conjugate for budesonide delivery in inflammatory bowel diseases.

PubMed

Sun, Qijuan; Luan, Lin; Arif, Muhammad; Li, Jiaxin; Dong, Quan-Jiang; Gao, Yuanyuan; Chi, Zhe; Liu, Chen-Guang

2018-06-01

The purpose of this study was to develop an oral nanocarrier as budesonide delivery system and to evaluate its therapeutic potential for inflammatory bowel disease (IBD). The nanoparticles (NPs) based on an amphiphilic inulin polymer with 4-aminothiophenol (ATP) grafted onto carboxymethyl inulin (CMI) were prepared. The particle sizes were about 210.18 nm and had the obvious pH/redox sensitive swelling transitions. The drug-release study of NPs <-- >in vitro showed a low release rate (about 45 wt%) in GSH-free media, whereas high release rate (about 80 wt%) in the media containing 20 mM GSH, exhibiting a redox-responsive property. Further in vivo experiments found the NPs tended to accumulate in inflamed sites, and exerted excellent therapeutic efficacy in comparison to drug suspension in colitis mice model. All the results demonstrated that the redox-sensitive NPs, based on amphiphilic inulin, may be used as colon-targeted drug delivery for the treatment of IBD. Copyright © 2017. Published by Elsevier Ltd.

Corrective Action Investigation Plan for Corrective Action Unit 106: Areas 5, 11 Frenchman Flat Atmospheric Sites, Nevada National Security Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick Matthews

2011-07-01

Corrective Action Unit 106 comprises the four corrective action sites (CASs) listed below: • 05-20-02, Evaporation Pond • 05-23-05, Atmospheric Test Site - Able • 05-45-04, 306 GZ Rad Contaminated Area • 05-45-05, 307 GZ Rad Contaminated Area These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viablemore » CAAs that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the data quality objectives (DQOs) developed on January 19, 2010, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 106. The presence and nature of contamination at CAU 106 will be evaluated based on information collected from a field investigation. The CAU includes land areas impacted by the release of radionuclides from groundwater pumping during the Radionuclide Migration study program (CAS 05-20-02), a weapons-related airdrop test (CAS 05-23-05), and unknown support activities at two sites (CAS 05-45-04 and CAS 05-45-05). The presence and nature of contamination from surface-deposited radiological contamination from CAS 05-23-05, Atmospheric Test Site - Able, and other types of releases (such as migration and excavation as well as any potential releases discovered during the investigation) from the remaining three CASs will be evaluated using soil samples collected from the locations most likely containing contamination, if present. Appendix A provides a detailed discussion of the DQO methodology and the DQOs specific to each CAS. The scope of the corrective action investigation for CAU 106 includes the following activities: • Conduct radiological surveys. • Collect and submit environmental samples for laboratory analysis to determine internal dose rates and the presence of contaminants of concern. • If contaminants of concern are present, collect additional samples to define the extent of the contamination and determine the area where the total effective dose at the site exceeds final action levels (i.e., corrective action boundary). • Collect samples of investigation-derived waste, as needed, for waste management purposes.« less

Clinical potential of a silk sericin-releasing bioactive wound dressing for the treatment of split-thickness skin graft donor sites.

PubMed

Siritientong, Tippawan; Angspatt, Apichai; Ratanavaraporn, Juthamas; Aramwit, Pornanong

2014-01-01

An ethyl alcohol-precipitated silk sericin/PVA scaffold that controlled the release of silk sericin was previously developed and applied for the treatment of full-thickness wounds in rats and demonstrated efficient healing. In this study, we aimed to further evaluate the clinical potential of this scaffold, hereafter called "silk sericin-releasing wound dressing", for the treatment of split-thickness skin graft donor sites by comparison with the clinically available wound dressing known as "Bactigras®". In vitro characterization and in vivo evaluation for safety of the wound dressings were performed. A clinical trial of the wound dressings was conducted according to standard protocols. The sericin released from the wound dressing was not toxic to HaCat human keratinocytes. A peel test indicated that the silk sericin-releasing wound dressing was less adhesive than Bactigras®, potentially reducing trauma and the risk of repeated injury upon removal. There was no evidence of skin irritation upon treatment with either wound dressing. When tested in patients with split-thickness skin graft donor sites, the wounds treated with the silk sericin-releasing wound dressing exhibited complete healing at 12 ± 5.0 days, whereas those treated with Bactigras® were completely healed at 14 ± 5.2 days (p = 1.99 × 10(-4)). In addition, treatment with the silk sericin-releasing wound dressing significantly reduced pain compared with Bactigras® particularly during the first 4 postoperative days (p = 2.70 × 10(-5) on day 1). We introduce this novel silk sericin-releasing wound dressing as an alternative treatment for split-thickness skin graft donor sites.

IFN-γ Release Assay Result Is Associated with Disease Site and Death in Active Tuberculosis.

PubMed

Auld, Sara C; Lee, Scott H; Click, Eleanor S; Miramontes, Roque; Day, Cheryl L; Gandhi, Neel R; Heilig, Charles M

2016-12-01

The IFN-γ release assays and tuberculin skin tests are used to support the diagnosis of both latent and active tuberculosis. However, we previously demonstrated that a negative tuberculin test in active tuberculosis is associated with disseminated disease and death. It is unknown whether the same associations exist for IFN-γ release assays. To determine the association between these tests and site of tuberculosis and death among persons with active tuberculosis. We analyzed IFN-γ release assays and tuberculin test results for all persons with culture-confirmed tuberculosis reported to the U.S. National Tuberculosis Surveillance System from 2010 to 2014. We used logistic regression to calculate the association between these tests and site of disease and death. A total of 24,803 persons with culture-confirmed tuberculosis had either of these test results available for analysis. Persons with a positive tuberculin test had lower odds of disseminated disease (i.e., miliary or combined pulmonary and extrapulmonary disease), but there was no difference in the odds of disseminated disease with a positive IFN-γ release assay. However, persons who were positive to either of these tests had lower odds of death. An indeterminate IFN-γ release assay result was associated with greater odds of both disseminated disease and death. Despite perceived equivalence in clinical practice, IFN-γ release assays and tuberculin test results have different associations with tuberculosis site, yet similar associations with the risk of death. Furthermore, an indeterminate IFN-γ release assay result in a person with active tuberculosis is not unimportant, and rather carries greater odds of disseminated disease and death. Prospective study may improve our understanding of the underlying mechanisms by which these tests are associated with disease localization and death.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1988. Fifty-year commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 71 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 16 person-rem to a low of 0.0011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.1 person-rem. The total population dose for all sites was estimated at 75 person-rem for the 150 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 3 {times} 10{sup {minus}7} mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year).« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1988. Volume 10

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1988. Fifty-year commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 71 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 16 person-rem to a low of 0.0011 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 1.1 person-rem. The total population dose for all sites was estimated at 75 person-rem for the 150 million people considered at risk. The site average individual dose commitment from all pathways ranged from a low of 3 {times} 10{sup {minus}7} mrem to a high of 0.02 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites. However, licensee calculation of doses to the maximally exposed individual at some sites indicated values of up to approximately 100 times average individual doses (on the order of a few millirem per year).« less

Effects of site preparation and release on the survival and growth of planted bare-root and container-grown longleaf pine

Treesearch

William D. Boyer

1988-01-01

Survival and grow of these plantings were observed for 3 years on a variety of coatal plain sites in Georgia.Treatments included high and low levels of pre-planting site preparation, with and without post-planting release with a herbicide. After 3 years, survival was much better for container (79%) than for bare-root (52%) stock. Survival was better with the high level...

Effect of peptidase inhibition on the pattern of intraspinally released immunoreactive substance P detected with antibody microprobes.

PubMed

Duggan, A W; Schaible, H G; Hope, P J; Lang, C W

1992-05-08

Antibody microprobes bearing antibodies to the C-terminus of substance P (SP) were used to measure release of immunoreactive (ir) SP in the dorsal horn of barbiturate anaesthetized spinal cats. Electrical stimulation of unmyelinated primary afferents of the ipsilateral tibial nerve produced a relatively localised release of ir SP in the superficial dorsal horn. Prior microinjection of the peptidase inhibitors kelatorphan and enalaprilat in the dorsal horn resulted in ir SP being detected over the whole of the dorsal horn and the overlying dorsal column. This pattern had previously been observed with evoked release of ir neurokinin A and supports the proposal that a slow degradation results in a neuropeptide accessing many sites remote from sites of release.

PLGA microspheres encapsulating siRNA.

PubMed

De Rosa, Giuseppe; Salzano, Giuseppina

2015-01-01

The therapeutic use of small interfering RNA (siRNA) represents a new and powerful approach to suppress the expression of pathologically genes. However, biopharmaceutical drawbacks, such as short half-life, poor cellular uptake, and unspecific distribution into the body, hamper the development of siRNA-based therapeutics. Poly(lactide-co-glycolide), (PLGA) microspheres can be a useful tool to overcome these issues. siRNA can be encapsulated into the PLGA microspheres, which protects the loaded nucleic acid against the enzymatic degradation. Moreover, PLGA microspheres can be injected directly into the action site, where the siRNA can be released in controlled manner, thus avoiding the need of frequent invasive administrations. The complete biodegradability of PLGA to monomers easily metabolized by the body, and its approval by FDA and EMA for parenteral administration, assure the safety of this copolymer and do not require the removal of the device after the complete drug release. In chapter, a basic protocol for the preparation of PLGA microspheres encapsulating siRNA is described. This protocol is based on a double emulsion/solvent evaporation technique, a well known and easy to reproduce method. This specific protocol has been developed to encapsulate a siRNA anti-TNFα in PLGA microspheres, and it has been designed and optimized to achieve high siRNA encapsulation efficiency and slow siRNA release in vitro. However, it can be extended also to other siRNA as well as other RNA or DNA-based oligonucleotides (miRNA, antisense, decoy, etc.). Depending on the applications, chemical modifications of the backbone and site-specific modification within the siRNA sequences could be required.

Section 9: Ground Water - Likelihood of Release

EPA Pesticide Factsheets

HRS training. the ground water pathway likelihood of release factor category reflects the likelihood that there has been, or will be, a release of hazardous substances in any of the aquifers underlying the site.

A GIS approach to conducting biogeochemical research in wetlands

NASA Technical Reports Server (NTRS)

Brannon, David P.; Irish, Gary J.

1985-01-01

A project was initiated to develop an environmental data base to address spatial aspects of both biogeochemical cycling and resource management in wetlands. Specific goals are to make regional methane flux estimates and site specific water level predictions based on man controlled water releases within a wetland study area. The project will contribute to the understanding of the Earth's biosphere through its examination of the spatial variability of methane emissions. Although wetlands are thought to be one of the primary sources for release of methane to the atmosphere, little is known about the spatial variability of methane flux. Only through a spatial analysis of methane flux rates and the environmental factors which influence such rates can reliable regional and global methane emissions be calculated. Data will be correlated and studied from Landsat 4 instruments, from a ground survey of water level recorders, precipitation recorders, evaporation pans, and supplemental gauges, and from flood gate water release; and regional methane flux estimates will be made.

pH- and ion-sensitive polymers for drug delivery

PubMed Central

Yoshida, Takayuki; Lai, Tsz Chung; Kwon, Glen S; Sako, Kazuhiro

2013-01-01

Introduction Drug delivery systems (DDSs) are important for effective, safe, and convenient administration of drugs. pH- and ion-responsive polymers have been widely employed in DDS for site-specific drug release due to their abilities to exploit specific pH- or ion-gradients in the human body. Areas covered Having pH-sensitivity, cationic polymers can mask the taste of drugs and release drugs in the stomach by responding to gastric low pH. Anionic polymers responsive to intestinal high pH are used for preventing gastric degradation of drug, colon drug delivery and achieving high bioavailability of weak basic drugs. Tumor-targeted DDSs have been developed based on polymers with imidazole groups or poly(β-amino ester) responsive to tumoral low pH. Polymers with pH-sensitive chemical linkages, such as hydrazone, acetal, ortho ester and vinyl ester, pH-sensitive cell-penetrating peptides and cationic polymers undergoing pH-dependent protonation have been studied to utilize the pH gradient along the endocytic pathway for intracellular drug delivery. As ion-sensitive polymers, ion-exchange resins are frequently used for taste-masking, counterion-responsive drug release and sustained drug release. Polymers responding to ions in the saliva and gastrointestinal fluids are also used for controlled drug release in oral drug formulations. Expert opinion Stimuli-responsive DDSs are important for achieving site-specific and controlled drug release; however, intraindividual, interindividual and intercellular variations of pH should be considered when designing DDSs or drug products. Combination of polymers and other components, and deeper understanding of human physiology are important for development of pH- and ion-sensitive polymeric DDS products for patients. PMID:23930949

Photoactive Nitric Oxide Delivery Systems based on Metal Nitrosyl-Biomaterial Composites

NASA Astrophysics Data System (ADS)

Heilman, Brandon James

Gaseous NO has been recognized as a potent antibiotic even against highly drug-resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) in both animal and human studies. However, difficulties in the delivery of the toxic (and reactive) gas demands innovative techniques to deliver NO in a controlled manner to malignant sites throughout the body. Metal nitrosyls reported by our group have demonstrated rapid NO release under the complete control of visible and NIR light. Careful incorporation of these photoactive nitrosyls into polymer matrices has afforded a set of nitrosyl-polymer composites in order to localize the NO-donors at a targeted site, ensure reliable NO release kinetics in vivo, and prevent potentially cytotoxic interactions of the metal nitrosyl or its reaction-products with the treatment site. The work presented in this thesis was pursued to derive clinically relevant NO-delivery systems and demonstrate their utility for the treatment of infection. In chapter 2, an NO-releasing polyurethane film (PUX-NO) is described with dispersed xerogel particles containing up to 3 mol% of [Mn(PaPy 3)(NO)](ClO4) entrapped in a silica matrix and swelled with excess moisture. The polyurethane based xerogel-nitrosyl (PUX-NO) films demonstrated rapid NO photorelease upon illumination with low-power visible light which was sufficient to eradicate clinically relevant loads (105 CFU mL-1 ) of several gram-positive and gram-negative pathogenic bacteria, including a strain of methicillin-resistant of S. aureus. The results of this study suggest that PUX-NO films are suitable for use as a NO-releasing occlusive film for the treatment of skin and soft-tissue infections or chronic, non-healing wounds. Since the NO-release rate from the films can be modulated by simple adjustment of the intensity of the light source, the films could be used to first clear the microbial burden from the wound site using high fluxes of NO, and then, provide a moderate, sustained flux of NO in order to accelerate the wound healing process and mitigate the potential for recurrent infections. Chapter 3 details the incorporation of a photoactive Mn nitrosyl in the mesopores of a MCM-41 type silicate to afford {Mn-NO} MCM-41. To increase the interaction between the nitrosyl and the MCM-41 pore walls, an aluminosilicate-based material (Al-MCM-41) was used with 3 mol% AlIII substituted for tetrahedral SiIV sites, which introduced negative point charges capable of electrostatically binding the cationic nitrosyl. Homegenous loading of the Mn nitrosyl (up to 25 wt.%) throughout the hexagonally packed, uni-dimensional mesopores of the Al-MCM-41 particles was determined using various analytical techniques including ICP-MS, FAAS, PXRD, N2 sorption isometry, UV-vis DRS, FTIR, and SEM-EDX. Exposure of {Mn-NO} Al-MCM-41 to visible light of similar intensity to sunlight on a bright day (100 mW cm-2) released high fluxes of NO that effectively eradicated a multi-drug resistant strain of Acinetobacter baumannii.. In another study, described in Chapter 4, the powdery material was used to demonstrate the effect of NO on the dimorphic fungal pathogen, Candida albicans. Since the virulence of C. albicans is dependent on the ability of the fungus to switch growth from an ovoid yeast form to an elongated hyphal form, careful studies of the dose-dependent effect of NO released from {Mn-NO} Al-MCM-41 on morphologically pure cultures of C. albicans in the yeast and hyphal forms have revealed that the hyphal form is more susceptible to NO. Results of this work suggest that photo-activated NO-donating materials of this type could prevent commensal populations of C. albicans from invading vulnerable tissue by blocking the over-growth of the tissue penetrating hyphal form of the fungus.

Noble gases released by vacuum crushing of EETA 79001 glass

NASA Technical Reports Server (NTRS)

Wiens, R. C.

1988-01-01

An EETA 79001 glass sample was crushed in a vacuum to observe the gases released. About 15 pct of the total gas concentrations were a mixture of a small amount of SPB-type gas with larger proportions of another air-like component. Less than 5 pct of the SPB gas was released by crushing, while 36-40 pct of the EETV (indigenous) gas was crush-released. The results are consistent with a siting of the EETV component in 10-100 micron vesicles seen in the glass. It is suggested that the SPB component is either in vesicles less than 6 microns in diameter or is primarily sited elsewhere.

Availability and Distribution of Base Flow in Lower Honokohau Stream, Island of Maui

USGS Publications Warehouse

Fontaine, Richard A.

2003-01-01

Honokohau Stream is one of the few perennial streams in the Lahaina District of West Maui. Current Honokohau water-use practices often lead to conflicts among water users, which are most evident during periods of base flow. To better manage the resource, data are needed that describe the availability and distribution of base flow in lower Honokohau Stream and how base flow is affected by streamflow diversion and return-flow practices. Flow-duration discharges for percentiles ranging from 50 to 95 percent were estimated at 13 locations on lower Honokohau Stream using data from a variety of sources. These sources included (1) available U.S. Geological Survey discharge data, (2) published summaries of Maui Land & Pineapple Company, Inc. diversion and water development-tunnel data, (3) seepage run and low-flow partial-record discharge measurements made for this study, and (4) current (2003) water diversion and return-flow practices. These flow-duration estimates provide a detailed characterization of the distribution and availability of base flow in lower Honokohau Stream. Estimates of base-flow statistics indicate the significant effect of Honokohau Ditch diversions on flow in the stream. Eighty-six percent of the total flow upstream from the ditch is diverted from the stream. Immediately downstream from the diversion dam there is no flow in the stream 91.2 percent of the time, except for minor leakage through the dam. Flow releases at the Taro Gate, from Honokohau Ditch back into the stream, are inconsistent and were found to be less than the target release of 1.55 cubic feet per second on 9 of the 10 days on which measurements were made. Previous estimates of base-flow availability downstream from the Taro Gate release range from 2.32 to 4.6 cubic feet per second (1.5 to 3.0 million gallons per day). At the two principal sites where water is currently being diverted for agricultural use in the valley (MacDonald's and Chun's Dams), base flows of 2.32 cubic feet per second (1.5 million gallons per day) are available more than 95 percent of the time at MacDonald's Dam and 80 percent of the time at Chun's Dam. Base flows of 4.6 cubic feet per second (3.0 million gallons per day) are available 65 and 56 percent of the time, respectively. A base-flow water-accounting model was developed to estimate how flow-duration discharges for 13 sites on Honokohau Stream would change in response to a variety of flow release and diversion practices. A sample application of the model indicates that there is a 1 to 1 relation between changes in flow release rates at the Taro Gate and base flow upstream from MacDonald's Dam. At Chun's Dam the relation between Taro Gate releases and base flow varies with flow-duration percentiles. At the 95th and 60th percentiles, differences in base flow at Chun's Dam would equal about 50 and 90 percent of the change at the Taro Gate.

Controlled Release of Dexamethasone from Peptide Nanofiber Gels to Modulate Inflammatory Response

PubMed Central

Webber, Matthew J.; Matson, John B.; Tamboli, Vibha K.; Stupp, Samuel I.

2012-01-01

New biomaterials that have the ability to locally suppress an immune response could have broad therapeutic use in the treatment of diseases characterized by acute or chronic inflammation or as a strategy to facilitate improved efficacy in cell or tissue transplantation. We report here on the preparation of a modular peptide amphiphile (PA) capable of releasing an anti-inflammatory drug, dexamethasone (Dex), by conjugation via a labile hydrazone linkage. This molecule self-assembled in water into long supramolecular nanofibers when mixed with a similar PA lacking the drug conjugate, and the addition of calcium salt to screen electrostatic repulsion between nanofibers promoted gel formation. These nanofiber gels demonstrated sustained release of soluble Dex for over one month in physiologic media. The Dex released from these gels maintained its anti-inflammatory activity when evaluated in vitro using a human inflammatory reporter cell line and furthermore preserved cardiomyocytes viability upon induced oxidative stress. The ability of this gel to mitigate the inflammatory response in cell transplantation strategies was evaluated using cell-surrogate polystyrene microparticles suspended in the nanofiber gel that were then subcutaneously injected in a mouse. Live animal luminescence imaging using the chemiluminescent reporter molecule luminol showed a significant reduction in inflammation at the site where particles were injected with Dex-PA compared to the site of injection for particles within a control PA in the same animal. Histological evidence suggested a marked reduction in the number of infiltrating inflammatory cells when particles were delivered within Dex-PA nanofiber gels and very little inflammation was observed at either 3 days or 21 days post-implantation. The use of Dex-PA could facilitate localized anti-inflammatory activity as a component of biomaterials designed for various applications in regenerative medicine and could specifically be a useful module for PA-based therapies. More broadly, these studies define a versatile strategy for facile synthesis of self-assembling peptide-based materials with the ability to control drug release. PMID:22748768

Supporting Best-Practice Literacy Instruction Utilizing National Standards: A Gradual-Release Model for Developing Site-Based Literacy Leaders

ERIC Educational Resources Information Center

Sableski, Mary-Kate; Arnold, Jackie Marshall

2017-01-01

Catholic elementary and secondary schools across the country recently adopted standards reflective of the Common Core State Standards to align instruction with state and national guidelines requiring the revision of curriculum and the adjustment of instruction to meet the new standards from an ideological model. This article describes a…

SUMMARY OF ACCIDENTAL RELEASES OF RADIOACTIVITY DETECTED OFF THE NEVADA TEST SITE, 1963-1986

EPA Science Inventory

Of the more than 450 underground nuclear explosives tests conducted at the Nevada Test Site from August 1963 (signing of the Limited Test Ban Treaty) through the end of 1986, only 23 accidentally released radioactivity that was detectable beyond the boundary of the NTS. Of these ...

Accidental Release of Chlorine from a Storage Facility and an On-Site Emergency Mock Drill: A Case Study

PubMed Central

Soman, Ambalathumpara Raman; Sundararaj, Gopalswamy

2015-01-01

In the current industrial scenario there is a serious need for formulating strategies to handle hazardous substances in the safest way. Manufacture, storage, and use of hazardous substances pose a serious risk to industry, people, and the environment. Accidental release of toxic chemicals can lead to emergencies. An emergency response plan (ERP) is inevitable to minimize the adverse effects of such releases. The on-site emergency plan is an integral component of any process safety and risk management system. This paper deals with an on-site emergency response plan for a chlorine manufacturing industry. It was developed on the basis of a previous study on chlorine release and a full scale mock drill has been conducted for testing the plan. Results indicated that properly trained personnel can effectively handle each level of incidents occurring in the process plant. As an extensive guideline to the district level government authorities for off-site emergency planning, risk zone has also been estimated with reference to a chlorine exposure threshold of 3 ppm. PMID:26171416

Computational prediction of muon stopping sites using ab initio random structure searching (AIRSS)

NASA Astrophysics Data System (ADS)

Liborio, Leandro; Sturniolo, Simone; Jochym, Dominik

2018-04-01

The stopping site of the muon in a muon-spin relaxation experiment is in general unknown. There are some techniques that can be used to guess the muon stopping site, but they often rely on approximations and are not generally applicable to all cases. In this work, we propose a purely theoretical method to predict muon stopping sites in crystalline materials from first principles. The method is based on a combination of ab initio calculations, random structure searching, and machine learning, and it has successfully predicted the MuT and MuBC stopping sites of muonium in Si, diamond, and Ge, as well as the muonium stopping site in LiF, without any recourse to experimental results. The method makes use of Soprano, a Python library developed to aid ab initio computational crystallography, that was publicly released and contains all the software tools necessary to reproduce our analysis.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1982. Volume 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.; Peloquin, R.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1982. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 51 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each sitemore » receiving various average dose commitments from the airborne pathways. The total dose commitments from both liquid and airborne pathways ranged from a high of 30 person-rem to a low of 0.007 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 130 person-rem for the 100 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 6 x 10/sup -7/ mrem to a high of 0.06 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Potential benefits of waste transmutation to the U.S. high-level waste respository

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michaels, G.E.

1995-10-01

This paper reexamines the potential benefits of waste transmutation to the proposed U.S. geologic repository at the Yucca Mountain site based on recent progress in the performance assessment for the Yucca Mountain base case of spent fuel emplacement. It is observed that actinides are assumed to have higher solubility than in previous studies and that Np and other actinides now dominate the projected aqueous releases from a Yucca Mountain repository. Actinides are also indentified as the dominant source of decay heat in the repository, and the effect of decay heat in perturbing the hydrology, geochemistry, and thermal characteristics of Yuccamore » Mountain are reviewed. It is concluded that the potential for thermally-driven, buoyant, gas-phase flow at Yucca Mountain introduces data and modeling requirements that will increase the costs of licensing the site and may cause the site to be unattractive for geologic disposal of wastes. A transmutation-enabled cold repository is proposed that might allow licensing of a repository to be based upon currently observable characteristics of the Yucca Mountain site.« less

Population dose commitments due to radioactive releases from nuclear-power-plant sites in 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peloquin, R.A.; Schwab, J.D.; Baker, D.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1978. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showing the fraction of the total population within 2 to 80 km around each site receiving variousmore » average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 200 person-rem to a low of 0.0004 person-rem with an arithmetic mean of 14 person-rem. The total population dose for allsites was estimated at 660 person-rem for the 93 million people considered at risk. The average individual dose commitment from all pathways on a site basis ranged from a low of 3 x 10/sup -6/ mrem to a high of 0.08 mrem. No attempt was made in this study to determine the maximum dose commitment received by any one individual from the radionuclides released at any of the sites.« less

Novel Pentablock Copolymers as Thermosensitive Self-Assembling Micelles for Ocular Drug Delivery

PubMed Central

Alami-Milani, Mitra; Zakeri-Milani, Parvin; Valizadeh, Hadi; Salehi, Roya; Salatin, Sara; Naderinia, Ali; Jelvehgari, Mitra

2017-01-01

Many studies have focused on how drugs are formulated in the sol state at room temperature leading to the formation of in situ gel at eye temperature to provide a controlled drug release. Stimuli-responsive block copolymer hydrogels possess several advantages including uncomplicated drug formulation and ease of application, no organic solvent, protective environment for drugs, site-specificity, prolonged and localized drug delivery, lower systemic toxicity, and capability to deliver both hydrophobic and hydrophilic drugs. Self-assembling block copolymers (such as diblock, triblock, and pentablock copolymers) with large solubility variation between hydrophilic and hydrophobic segments are capable of making temperature-dependent micellar assembles, and with further increase in the temperature, of jellifying due to micellar aggregation. In general, molecular weight, hydrophobicity, and block arrangement have a significant effect on polymer crystallinity, micelle size, and in vitro drug release profile. The limitations of creature triblock copolymers as initial burst release can be largely avoided using micelles made of pentablock copolymers. Moreover, formulations based on pentablock copolymers can sustain drug release for a longer time. The present study aims to provide a concise overview of the initial and recent progresses in the design of hydrogel-based ocular drug delivery systems. PMID:28507933

Spike-independent release of ATP from Xenopus spinal neurons evoked by activation of glutamate receptors

PubMed Central

Brown, Paul; Dale, Nicholas

2002-01-01

As the release of ATP from neurons has only been directly studied in a few cases, we have used patch sniffing to examine ATP release from Xenopus spinal neurons. ATP release was detected following intracellular current injection to evoke spikes. However, spiking was not essential as both glutamate and NMDA could evoke release of ATP in the presence of TTX. Neither acetylcholine nor high K+ was effective at inducing ATP release in the presence of TTX. Although Cd2+ blocked glutamate-evoked release of ATP suggesting a dependence on Ca2+ entry, neither ω-conotoxin-GVIA nor nifedipine prevented ATP release. N-type and L-type channels are thus not essential for glutamate-evoked ATP release. That glutamate receptors can elicit release in the absence of spiking suggests a close physical relationship between these receptors, the Ca2+ channels and release sites. As the dependence of ATP release on the influx of Ca2+ through Ca2+ channel subtypes differs from that of synaptic transmitter release, ATP may be released from sites that are distinct from those of the principal transmitter. In addition to its role as a fast transmitter, ATP may thus be released as a consequence of the activation of excitatory glutamatergic synapses and act to signal information about activity patterns in the nervous system. PMID:11986374

Vesicle Motion during Sustained Exocytosis in Chromaffin Cells: Numerical Model Based on Amperometric Measurements.

PubMed

Jarukanont, Daungruthai; Bonifas Arredondo, Imelda; Femat, Ricardo; Garcia, Martin E

2015-01-01

Chromaffin cells release catecholamines by exocytosis, a process that includes vesicle docking, priming and fusion. Although all these steps have been intensively studied, some aspects of their mechanisms, particularly those regarding vesicle transport to the active sites situated at the membrane, are still unclear. In this work, we show that it is possible to extract information on vesicle motion in Chromaffin cells from the combination of Langevin simulations and amperometric measurements. We developed a numerical model based on Langevin simulations of vesicle motion towards the cell membrane and on the statistical analysis of vesicle arrival times. We also performed amperometric experiments in bovine-adrenal Chromaffin cells under Ba2+ stimulation to capture neurotransmitter releases during sustained exocytosis. In the sustained phase, each amperometric peak can be related to a single release from a new vesicle arriving at the active site. The amperometric signal can then be mapped into a spike-series of release events. We normalized the spike-series resulting from the current peaks using a time-rescaling transformation, thus making signals coming from different cells comparable. We discuss why the obtained spike-series may contain information about the motion of all vesicles leading to release of catecholamines. We show that the release statistics in our experiments considerably deviate from Poisson processes. Moreover, the interspike-time probability is reasonably well described by two-parameter gamma distributions. In order to interpret this result we computed the vesicles' arrival statistics from our Langevin simulations. As expected, assuming purely diffusive vesicle motion we obtain Poisson statistics. However, if we assume that all vesicles are guided toward the membrane by an attractive harmonic potential, simulations also lead to gamma distributions of the interspike-time probability, in remarkably good agreement with experiment. We also show that including the fusion-time statistics in our model does not produce any significant changes on the results. These findings indicate that the motion of the whole ensemble of vesicles towards the membrane is directed and reflected in the amperometric signals. Our results confirm the conclusions of previous imaging studies performed on single vesicles that vesicles' motion underneath plasma membranes is not purely random, but biased towards the membrane.

Vesicle Motion during Sustained Exocytosis in Chromaffin Cells: Numerical Model Based on Amperometric Measurements

PubMed Central

Jarukanont, Daungruthai; Bonifas Arredondo, Imelda; Femat, Ricardo; Garcia, Martin E.

2015-01-01

Chromaffin cells release catecholamines by exocytosis, a process that includes vesicle docking, priming and fusion. Although all these steps have been intensively studied, some aspects of their mechanisms, particularly those regarding vesicle transport to the active sites situated at the membrane, are still unclear. In this work, we show that it is possible to extract information on vesicle motion in Chromaffin cells from the combination of Langevin simulations and amperometric measurements. We developed a numerical model based on Langevin simulations of vesicle motion towards the cell membrane and on the statistical analysis of vesicle arrival times. We also performed amperometric experiments in bovine-adrenal Chromaffin cells under Ba2+ stimulation to capture neurotransmitter releases during sustained exocytosis. In the sustained phase, each amperometric peak can be related to a single release from a new vesicle arriving at the active site. The amperometric signal can then be mapped into a spike-series of release events. We normalized the spike-series resulting from the current peaks using a time-rescaling transformation, thus making signals coming from different cells comparable. We discuss why the obtained spike-series may contain information about the motion of all vesicles leading to release of catecholamines. We show that the release statistics in our experiments considerably deviate from Poisson processes. Moreover, the interspike-time probability is reasonably well described by two-parameter gamma distributions. In order to interpret this result we computed the vesicles’ arrival statistics from our Langevin simulations. As expected, assuming purely diffusive vesicle motion we obtain Poisson statistics. However, if we assume that all vesicles are guided toward the membrane by an attractive harmonic potential, simulations also lead to gamma distributions of the interspike-time probability, in remarkably good agreement with experiment. We also show that including the fusion-time statistics in our model does not produce any significant changes on the results. These findings indicate that the motion of the whole ensemble of vesicles towards the membrane is directed and reflected in the amperometric signals. Our results confirm the conclusions of previous imaging studies performed on single vesicles that vesicles’ motion underneath plasma membranes is not purely random, but biased towards the membrane. PMID:26675312

Evaluation of two low-flow releases from Big Tujunga Reservoir, Los Angeles County, California, 2003

USGS Publications Warehouse

Mendez, Gregory O.

2005-01-01

Since 1973, the Santa Ana Sucker (Catostomus santaanae) has been listed as a threatened species under the Endangered Species Act. The Lower Big Tujunga Creek, in Los Angeles County, is one of the areas in southern California where the Santa Ana Sucker is still present. This study was designed to assess two flow releases from Big Tujunga Dam that may contribute to favorable habitat conditions for the Santa Ana Sucker. It is important for the Santa Ana Sucker's survival that pools in the lower reach of the study area are replenished periodically. The focus of the study area was on the Lower Big Tujunga Creek within a reach extending approximately 6 miles downstream from the Big Tujunga Reservoir. Six sites were established from the Big Tujunga Dam to Delta Flats day-use area for data collection. This report describes the study design, discharge measurements, and the flow data collected from the two releases. Two scheduled flows (phases 1 and 2) were released from the Big Tujunga Reservoir in August and September 2003. During the first phase, which lasted 50 hours, travel times from the dam to four sites downstream were determined. Arrival times at the four sites were determined on the basis of temperature data. Travel time from the dam to site 6 (the furthest downstream site) was about 51.5 hours. Travel times for subreaches were 3 hours from site 1 to site 2, 6.5 hours from site 2 to site 3, almost 18 hours from site 3 to site 4, and 24 hours from site 4 to site 6. The temperature probe at site 5 was destroyed, and thus the arrival time could not be estimated. A probe that measures stage was placed in one of the many pools downstream from site 4 to evaluate a typical pool response to a low-flow release. Also, discharge measurements were taken at four sites along the study reach. In phase 2, which lasted 5 days (121 hours), flow losses along the 6-mile reach were analyzed. Losses were estimated by measuring difference in flow from the dam to sites 3, 4, 5, and 6, when flow was most stable at each site or when the last measurement made before flow decreased due to flow from dam being shut off. Losses in the plunge pool, directly below the dam were assumed to be negligible for this study. Overall creek loss between the dam and site 6 (the last site) was estimated to be between 4.0 and 4.2 ft3/s (cubic feet per second). Estimated losses between the dam and intermediate sites were about 1.5 ft3/s to site 3; 2.5 ft3/s to site 4; and between 3.7 and 4.1 ft3/s to site 5.

Dose commitments due to radioactive releases from nuclear power plant sites in 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population and individual radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1989. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 72 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is an estimate of individual doses which are compared with 10 CFR Partmore » 50, Appendix I design objectives. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 14 person-rem to a low of 0.005 person-rem for the sites with plants in operation and producing power during the year. The arithmetic mean was 1.2 person-rem. The total population dose for all sites was estimated at 84 person-rem for the 140 million people considered at risk. The individual dose commitments estimated for all sites were below the Appendix I design objectives.« less

Dose commitments due to radioactive releases from nuclear power plant sites in 1989. Volume 11

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

Population and individual radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1989. Fifty-year dose commitments for a one-year exposure from both liquid and atmospheric releases were calculated for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 72 reactor sites. This report tabulates the results of these calculations, showing the dose commitments for both water and airborne pathways for each age group and organ. Also included for each of the sites is an estimate of individual doses which are compared with 10 CFR Partmore » 50, Appendix I design objectives. The total collective dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 14 person-rem to a low of 0.005 person-rem for the sites with plants in operation and producing power during the year. The arithmetic mean was 1.2 person-rem. The total population dose for all sites was estimated at 84 person-rem for the 140 million people considered at risk. The individual dose commitments estimated for all sites were below the Appendix I design objectives.« less

Population dose commitments due to radioactive releases from nuclear power plant sites in 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.; Peloquin, R.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1983. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each of 52 sites. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each of the sites is a histogram showing the fraction of the total population within 2 to 80 km aroundmore » each site receiving various average dose commitments from the airborne pathways. The total dose commitments (from both liquid and airborne pathways) for each site ranged from a high of 45 person-rem to a low of 0.002 person-rem for the sites with plants operating throughout the year with an arithmetic mean of 3 person-rem. The total population dose for all sites was estimated at 170 person-rem for the 100 million people considered at risk.« less

[Polymeric drug carriers activated by ultrasounds energy].

PubMed

Kik, Krzysztof; Lwow, Felicja; Szmigiero, Leszek

2007-01-01

In the last two decades an extensive research on the employment of ultrasounds in anticancer therapy has been noticed. So far ultrasounds have been widely used in medicine for diagnostic purposes (ultrasonography), but their great therapeutic potential and the development of polymer based antineoplastic drug carriers have persuaded many investigators to start research on the employment of ultrasounds in anticancer therapy. A new therapeutic concept based on the controlled drug's molecules release from their transporting polymer carriers has been proposed. Cavitation, a phenomenon characteristic for the action of ultrasounds, is used to destroy polymeric drug carriers and for drug release in target sites. The sonodynamic therapy (SDT) which utilizes ultrasonic waves for "acoustic drug activation" leading to the enhancement of cytotoxic activity of some drugs has also been developed. Furthermore, a long standing research on ultrasounds resulted in a new concept based on hyperthermia. This method of cancer treatment does not require any chemotherapeutic agent to be applied.

Stimuli-responsive chitosan-based nanocarriers for cancer therapy

PubMed Central

Fathi, Marziyeh; Sahandi Zangabad, Parham; Majidi, Sima; Barar, Jaleh; Erfan-Niya, Hamid

2017-01-01

Introduction: Stimuli-responsive nanocarriers offer unique advantages over the traditional drug delivery systems (DDSs) in terms of targeted drug delivery and on-demand release of cargo drug molecules. Of these, chitosan (CS)-based DDSs offer several advantages such as high compatibility with biological settings. Methods: In this study, we surveyed the literature in terms of the stimuli-responsive nanocarriers and discussed the most recent advancements in terms of CS-based nanosystems and their applications in cancer therapy and diagnosis. Results: These advanced DDSs are able to release the entrapped drugs in response to a specific endogenous stimulus (e.g., pH, glutathione concentration or certain enzymes) or exogenous stimulus (e.g., temperature, light, ultrasound, and magnetic field) at the desired time and target site. Dual-responsive nanocarriers by the combination of different stimuli have also been developed as efficient and improved DDSs. Among the stimuli-responsive nanocarriers, CS-based DDSs offer several advantages, including biocompatibility and biodegradability, antibacterial activity, ease of modification and functionalization, and non-immunogenicity. They are as one of the most ideal smart multifunction DDSs. Conclusion: The CS-based stimuli-responsive multifunctional nanosystems (NSs) offer unique potential for the targeted delivery of anticancer agents and provide great potential for on-demand and controlled-release of anticancer agents in response to diverse external/internal stimuli. PMID:29435435

Stimuli-responsive chitosan-based nanocarriers for cancer therapy.

PubMed

Fathi, Marziyeh; Sahandi Zangabad, Parham; Majidi, Sima; Barar, Jaleh; Erfan-Niya, Hamid; Omidi, Yadollah

2017-01-01

Introduction: Stimuli-responsive nanocarriers offer unique advantages over the traditional drug delivery systems (DDSs) in terms of targeted drug delivery and on-demand release of cargo drug molecules. Of these, chitosan (CS)-based DDSs offer several advantages such as high compatibility with biological settings. Methods: In this study, we surveyed the literature in terms of the stimuli-responsive nanocarriers and discussed the most recent advancements in terms of CS-based nanosystems and their applications in cancer therapy and diagnosis. Results: These advanced DDSs are able to release the entrapped drugs in response to a specific endogenous stimulus (e.g., pH, glutathione concentration or certain enzymes) or exogenous stimulus (e.g., temperature, light, ultrasound, and magnetic field) at the desired time and target site. Dual-responsive nanocarriers by the combination of different stimuli have also been developed as efficient and improved DDSs. Among the stimuli-responsive nanocarriers, CS-based DDSs offer several advantages, including biocompatibility and biodegradability, antibacterial activity, ease of modification and functionalization, and non-immunogenicity. They are as one of the most ideal smart multifunction DDSs. Conclusion: The CS-based stimuli-responsive multifunctional nanosystems (NSs) offer unique potential for the targeted delivery of anticancer agents and provide great potential for on-demand and controlled-release of anticancer agents in response to diverse external/internal stimuli.

Annotated bibliography of selected references on PCB and the Kalamazoo River Superfund Site, Michigan, 1982-2002

USGS Publications Warehouse

Simard, Andreanne

2003-01-01

Fifty six publications pertaining to the Kalamazoo River Superfund Site Publications stored in the Michigan Department of Environmental Quality Environmental Response Division site files are summarized. Publications are presented chronologically within four categories: PCB releases, PCB remediation, PCB safety, and PCB testing and cleanup. The text consists of bibliographical information and brief summaries of various published documents pertaining to PCB contamination of the Kalamazoo River. Numerous investigators such as the Michigan Department of Natural Resources, Georgia Pacific, and various contractors have demonstrated that multiple and at times continuous releases and re-releases of PCBs have occurred as a result of operations at papermill facilities owned and operated by the 'Potential Responsible Parties'.

Decoding the Dopamine Signal in Macaque Prefrontal Cortex: A Simulation Study Using the Cx3Dp Simulator

PubMed Central

Spühler, Isabelle Ayumi; Hauri, Andreas

2013-01-01

Dopamine transmission in the prefrontal cortex plays an important role in reward based learning, working memory and attention. Dopamine is thought to be released non-synaptically into the extracellular space and to reach distant receptors through diffusion. This simulation study examines how the dopamine signal might be decoded by the recipient neuron. The simulation was based on parameters from the literature and on our own quantified, structural data from macaque prefrontal area 10. The change in extracellular dopamine concentration was estimated at different distances from release sites and related to the affinity of the dopamine receptors. Due to the sparse and random distribution of release sites, a transient heterogeneous pattern of dopamine concentration emerges. Our simulation predicts, however, that at any point in the simulation volume there is sufficient dopamine to bind and activate high-affinity dopamine receptors. We propose that dopamine is broadcast to its distant receptors and any change from the local baseline concentration might be decoded by a transient change in the binding probability of dopamine receptors. Dopamine could thus provide a graduated ‘teaching’ signal to reinforce concurrently active synapses and cell assemblies. In conditions of highly reduced or highly elevated dopamine levels the simulations predict that relative changes in the dopamine signal can no longer be decoded, which might explain why cognitive deficits are observed in patients with Parkinson’s disease, or induced through drugs blocking dopamine reuptake. PMID:23951205

Establishment and abundance of Tetrastichus planipennisi (Hymenoptera: Eulophidae) in Michigan: potential for success in classical biocontrol of the invasive emerald ash borer (Coleoptera: Buprestidae).

PubMed

Duan, Jian J; Bauer, Leah S; Abell, Kristopher J; Lelito, Jonathan P; Van Driesche, Roy

2013-06-01

Tetrastichus planipennisi Yang is a gregarious larval endoparasitoid native to China and has been introduced to the United States since 2007 for classical biological control of the invasive emerald ash borer, Agrilus planipennis Fairmaire, an exotic beetle responsible for widespread ash mortality. Between 2007-2010, T. planipennisi adults (3,311-4,597 females and approximately 1,500 males per site) were released into each of six forest sites in three counties (Ingham, Gratiot, and Shiawassee) of southern Michigan. By the fall of 2012, the proportion of sampled trees with one or more broods of T. planipennisi increased to 92 and 83% in the parasitoid-release and control plots, respectively, from 33 and 4% in the first year after parasitoid releases (2009 fall for Ingham county sites and 2010 for other sites). Similarly, the mean number of T. planipennisi broods observed from sampled trees increased from less than one brood per tree in the first year after parasitoid releases to 2.46 (at control plots) to 3.08 (at release plots) broods by the fall of 2012. The rates of emerald ash borer larval parasitism by T. planipennisi also increased from 1.2% in the first year after parasitoid releases to 21.2% in the parasitoid-release plots, and from 0.2 to 12.8% for the control plots by the fall of 2012. These results demonstrate that T. planipennisi is established in southern Michigan and that its populations are increasing and expanding. This suggests that T. planipennisi will likely play a critical role in suppressing emerald ash borer populations in Michigan.

Remedial Investigation of Hanford Site Releases to the Columbia River - 13603

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lerch, J.A.; Hulstrom, L.C.; Sands, J.P.

2013-07-01

In south-central Washington State, the Columbia River flows through the U.S. Department of Energy Hanford Site. A primary objective of the Hanford Site cleanup mission is protection of the Columbia River, through remediation of contaminated soil and groundwater that resulted from its weapons production mission. Within the Columbia River system, surface water, sediment, and biota samples related to potential Hanford Site hazardous substance releases have been collected since the start of Hanford operations. The impacts from release of Hanford Site radioactive substances to the Columbia River in areas upstream, within, and downstream of the Hanford Site boundary have been previouslymore » investigated as mandated by the U.S. Department of Energy requirements under the Atomic Energy Act. The Remedial Investigation Work Plan for Hanford Site Releases to the Columbia River [1] was issued in 2008 to initiate assessment of the impacts under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 [2]. The work plan established a phased approach to characterize contaminants, assess current risks, and determine whether or not there is a need for any cleanup actions. Field investigation activities over a 120-mile stretch of the Columbia River began in October 2008 and were completed in 2010. Sampled media included surface water, pore water, surface and core sediment, island soil, and fish (carp, walleye, whitefish, sucker, small-mouth bass, and sturgeon). Information and sample results from the field investigation were used to characterize current conditions within the Columbia River and assess whether current conditions posed a risk to ecological or human receptors that would merit additional study or response actions under CERCLA. The human health and ecological risk assessments are documented in reports that were published in 2012 [3, 4]. Conclusions from the risk assessment reports are being summarized and integrated with remedial investigation/feasibility study (RI/FS) reports developed for upland areas, riparian areas, and groundwater in the Hanford Site River Corridor. The RI/FS reports will evaluate the impacts to soil, groundwater, and river sediments and lead to proposed cleanup actions and records of decision to address releases from the Hanford Site reactor operations. (authors)« less

Reduction-Responsive Polymeric Micelles and Vesicles for Triggered Intracellular Drug Release

PubMed Central

Sun, Huanli; Cheng, Ru; Deng, Chao

2014-01-01

Abstract Significance: The therapeutic effects of current micellar and vesicular drug formulations are restricted by slow and inefficient drug release at the pathological site. The development of smart polymeric nanocarriers that release drugs upon arriving at the target site has received a tremendous amount of attention for cancer therapy. Recent Advances: Taking advantage of a high reducing potential in the tumor tissues and in particular inside the tumor cells, various reduction-sensitive polymeric micelles and vesicles have been designed and explored for triggered anticancer drug release. These reduction-responsive nanosystems have demonstrated several unique features, such as good stability under physiological conditions, fast response to intracellular reducing environment, triggering drug release right in the cytosol and cell nucleus, and significantly improved antitumor activity, compared to traditional reduction-insensitive counterparts. Critical Issues: Although reduction-sensitive micelles and polymersomes have accomplished rapid intracellular drug release and enhanced in vitro antitumor effect, their fate inside the cells including the mechanism, site, and rate of reduction reaction remains unclear. Moreover, the systemic fate and performance of reduction-sensitive polymeric drug formulations have to be investigated. Future Directions: Biophysical studies should be carried out to gain insight into the degradation and drug release behaviors of reduction-responsive nanocarriers inside the tumor cells. Furthermore, novel ligand-decorated reduction-sensitive nanoparticulate drug formulations should be designed and explored for targeted cancer therapy in vivo. Antioxid. Redox Signal. 21, 755–767. PMID:24279980

A Review of Statistical Disclosure Control Techniques Employed by Web-Based Data Query Systems.

PubMed

Matthews, Gregory J; Harel, Ofer; Aseltine, Robert H

We systematically reviewed the statistical disclosure control techniques employed for releasing aggregate data in Web-based data query systems listed in the National Association for Public Health Statistics and Information Systems (NAPHSIS). Each Web-based data query system was examined to see whether (1) it employed any type of cell suppression, (2) it used secondary cell suppression, and (3) suppressed cell counts could be calculated. No more than 30 minutes was spent on each system. Of the 35 systems reviewed, no suppression was observed in more than half (n = 18); observed counts below the threshold were observed in 2 sites; and suppressed values were recoverable in 9 sites. Six sites effectively suppressed small counts. This inquiry has revealed substantial weaknesses in the protective measures used in data query systems containing sensitive public health data. Many systems utilized no disclosure control whatsoever, and the vast majority of those that did deployed it inconsistently or inadequately.

Preparation and evaluation of periodontal films based on polyelectrolyte complex formation.

PubMed

Kassem, Abeer Ahmed; Ismail, Fatma Ahmed; Naggar, Viviane Fahim; Aboulmagd, Elsayed

2015-05-01

Local intra-pocket drug delivery devices can provide an effective concentration of the antimicrobial agent at the site of action with avoidance of undesirable side effects. This study explored the application of chitosan-alginate and chitosan-pectin polyelectrolyte complex (PEC) films as drug release regulators for tetracycline HCl (Tc) to treat periodontal pockets. Periodontal films with 1:1 Tc:PEC ratio were prepared using 1:1 chitosan (Ch) to sodium alginate (A) or 1:3 Ch to pectin (P). The scanning electron microscope showed acceptable film appearance and differential scanning calorimetry analysis confirmed complex formation. The in vitro release studies for both films showed a burst drug release, followed by prolonged release for 70 h. A prolonged antibacterial activity of both films against Staphylococcus aureus ATCC 6538 was observed over a period of 21 days. Aging studies indicated that the five months storage period in freezer did not significantly influence the drug release profile or the antibacterial activity of both films. Clinical evaluation showed a significant reduction in pocket depth (p < 0.0001) to their normal values (≤3 mm). PEC films could be exploited as a prolonged drug release devices for treatment of periodontal pockets.

Study: Ozone Layer's Future Linked Strongly to Changes in Climate

Science.gov Websites

balloon to measure of the vertical profile of the ozone layer. NOAA scientists launch an ozonesonde via balloon to measure of the vertical profile of the ozone layer. NOAA releases ozonesondes at eight sites worldwide, including the Amundsen-Scott South Pole Station. It also uses satellite and ground-based systems

Biodegradable Bioadherent Microcapsules for Orally Administered Sustained Release Vaccines. Phase 1.

DTIC Science & Technology

1995-10-23

based on homology with the yeast alcohol oxidase (AOX) or histidine (his 4) loci and also upon the site of linearization of the plasmid since DNA ends...and Quantitation of Recombinant Fasciola Protein from the Pichia Yeast Expression System ...... 9 B. Production of Microcarriers...Recombinant Fasciola Protein from the Pichia Yeast Expression System ..... 15 B. Production of Microcarriers

Delivery of Alginate Scaffold Releasing Two Trophic Factors for Spinal Cord Injury Repair

PubMed Central

Grulova, I.; Slovinska, L.; Blaško, J.; Devaux, S.; Wisztorski, M.; Salzet, M.; Fournier, I.; Kryukov, O.; Cohen, S.; Cizkova, D.

2015-01-01

Spinal cord injury (SCI) has been implicated in neural cell loss and consequently functional motor and sensory impairment. In this study, we propose an alginate -based neurobridge enriched with/without trophic growth factors (GFs) that can be utilized as a therapeutic approach for spinal cord repair. The bioavailability of key GFs, such as Epidermal Growth factor (EGF) and basic Fibroblast Growth Factor (bFGF) released from injected alginate biomaterial to the central lesion site significantly enhanced the sparing of spinal cord tissue and increased the number of surviving neurons (choline acetyltransferase positive motoneurons) and sensory fibres. In addition, we document enhanced outgrowth of corticospinal tract axons and presence of blood vessels at the central lesion. Tissue proteomics was performed at 3, 7 and 10 days after SCI in rats indicated the presence of anti-inflammatory factors in segments above the central lesion site, whereas in segments below, neurite outgrowth factors, inflammatory cytokines and chondroitin sulfate proteoglycan of the lectican protein family were overexpressed. Collectively, based on our data, we confirm that functional recovery was significantly improved in SCI groups receiving alginate scaffold with affinity-bound growth factors (ALG +GFs), compared to SCI animals without biomaterial treatment. PMID:26348665

Representative Atmospheric Plume Development for Elevated Releases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eslinger, Paul W.; Lowrey, Justin D.; McIntyre, Justin I.

2014-02-01

An atmospheric explosion of a low-yield nuclear device will produce a large number of radioactive isotopes, some of which can be measured with airborne detection systems. However, properly equipped aircraft may not arrive in the region where an explosion occurred for a number of hours after the event. Atmospheric conditions will have caused the radioactive plume to move and diffuse before the aircraft arrives. The science behind predicting atmospheric plume movement has advanced enough that the location of the maximum concentrations in the plume can be determined reasonably accurately in real time, or near real time. Given the assumption thatmore » an aircraft can follow a plume, this study addresses the amount of atmospheric dilution expected to occur in a representative plume as a function of time past the release event. The approach models atmospheric transport of hypothetical releases from a single location for every day in a year using the publically available HYSPLIT code. The effective dilution factors for the point of maximum concentration in an elevated plume based on a release of a non-decaying, non-depositing tracer can vary by orders of magnitude depending on the day of the release, even for the same number of hours after the release event. However, the median of the dilution factors based on releases for 365 consecutive days at one site follows a power law relationship in time, as shown in Figure S-1. The relationship is good enough to provide a general rule of thumb for estimating typical future dilution factors in a plume starting at the same point. However, the coefficients of the power law function may vary for different release point locations. Radioactive decay causes the effective dilution factors to decrease more quickly with the time past the release event than the dilution factors based on a non-decaying tracer. An analytical expression for the dilution factors of isotopes with different half-lives can be developed given the power law expression for the non-decaying tracer. If the power-law equation for the median dilution factor, Df, based on a non-decaying tracer has the general form Df=a(×t)^(-b) for time t after the release event, then the equation has the form Df=e^(-λt)×a×t^(-b) for a radioactive isotope, where λ is the decay constant for the isotope.« less

A Mechanism for Intracellular Release of Na+ by Neurotransmitter: Sodium Symporters

PubMed Central

Malinauskaite, Lina; Reinhard, Linda; Lyons, Joseph A.; Yano, Hideaki; Javitch, Jonathan A.

2015-01-01

Neurotransmitter:sodium symporters (NSS) terminate synaptic signal transmission by Na+-dependent reuptake of released neurotransmitters, with key conformational states reported for a bacterial homolog LeuT and an inhibitor-bound Drosophila dopamine transporter. However, a coherent mechanism of Na+-driven transport has not been described. Here, we present two crystal structures of MhsT, a NSS member from Bacillus halodurans, in occluded inward-facing states with bound Na+ ions and L-Trp that provide insight into the cytoplasmic release of Na+. The switch from outward- to inward-oriented states is centered on the partial unwinding of transmembrane helix 5, which is facilitated by a conserved GlyX9Pro motif that opens an intracellular pathway for water to access the Na2 site. Based on our structural and functional findings we propose a mechanism according to which solvation through the TM5 pathway facilitates Na+ release from Na2 and the transition to an inward-open state. PMID:25282149

Assessment of plutonium in the Savannah River Site environment. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlton, W.H.; Evans, A.G.; Geary, L.A.

1992-12-31

Plutonium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fifth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. These are living documents, each to be revised and updated on a two-year schedule. This document describes the sources of plutonium in the environment, its release from SRS, environmental transport and ecological concentration of plutonium, and the radiological impact of SRS releases to the environment. Plutonium exists in the environment as a result of above-ground nuclearmore » weapons tests, the Chernobyl accident, the destruction of satellite SNAP 9-A, plane crashes involving nuclear weapons, and small releases from reactors and reprocessing plants. Plutonium has been produced at SRS during the operation of five production reactors and released in small quantities during the processing of fuel and targets in chemical separations facilities. Approximately 0.6 Ci of plutonium was released into streams and about 12 Ci was released to seepage basins, where it was tightly bound by clay in the soil. A smaller quantity, about 3.8 Ci, was released to the atmosphere. Virtually all releases have occurred in F- and H-Area separation facilities. Plutonium concentration and transport mechanisms for the atmosphere, surface water, and ground water releases have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases to the offsite maximum individual can be characterized by a total dose of 15 mrem (atmospheric) and 0.18 mrem (liquid), compared with the dose of 12,960 mrem from non-SRS sources during the same period of time (1954--1989). Plutonium releases from SRS facilities have resulted in a negligible impact to the environment and the population it supports.« less

Mutational Analysis of Rab3 Function for Controlling Active Zone Protein Composition at the Drosophila Neuromuscular Junction

PubMed Central

Roche, John P.; Alsharif, Peter; Graf, Ethan R.

2015-01-01

At synapses, the release of neurotransmitter is regulated by molecular machinery that aggregates at specialized presynaptic release sites termed active zones. The complement of active zone proteins at each site is a determinant of release efficacy and can be remodeled to alter synapse function. The small GTPase Rab3 was previously identified as playing a novel role that controls the distribution of active zone proteins to individual release sites at the Drosophila neuromuscular junction. Rab3 has been extensively studied for its role in the synaptic vesicle cycle; however, the mechanism by which Rab3 controls active zone development remains unknown. To explore this mechanism, we conducted a mutational analysis to determine the molecular and structural requirements of Rab3 function at Drosophila synapses. We find that GTP-binding is required for Rab3 to traffick to synapses and distribute active zone components across release sites. Conversely, the hydrolytic activity of Rab3 is unnecessary for this function. Through a structure-function analysis we identify specific residues within the effector-binding switch regions that are required for Rab3 function and determine that membrane attachment is essential. Our findings suggest that Rab3 controls the distribution of active zone components via a vesicle docking mechanism that is consistent with standard Rab protein function. PMID:26317909

Big Spring wind project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herrera, G.L.

1999-11-01

Harnessing the wind is not a new concept to Texans. But it is a concept that has evolved over the years from one of pumping water to fill stock tanks for watering livestock to one of providing electricity for the people of Texas. This evolution has occurred due to improved micro-siting techniques that help identify robust wind resource sites and wind turbine technology that improves wind capture and energy conversion efficiencies. Over the last seven to ten years this siting technology and wind turbine technology have significantly reduced the bus-bar cost associated with wind generation. On December 2, 1998, atmore » a public dedication of the Big Spring Wind Project, the first of 42 Vestas V47 wind turbines was released for commercial operation. Since that date an additional fifteen V47 Turbines have been placed into service. It is expected that the Big Spring Wind Project will be complete and released of full operation prior to the summer peak-load season of 1999. As of the writing of this paper (January 1999) the Vestas V47 turbines have performed as expected with excellent availability and, based on foregoing resource analysis, better than expected output.« less

Improving risk assessments for manufactured gas plant soils by measuring PAH availability.

PubMed

Stroo, Hans F; Nakles, David V; Kreitinger, Joseph P; Loehr, Raymond C; Hawthorne, Steven B; Luthy, Richard G; Holman, Hoi-Ying; LaPierre, Adrienne

2005-07-01

Remediation of soils at oil-gas manufactured gas plant (MGP) sites is driven primarily by the human health risks posed by the carcinogenic polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (BaP), that are associated with lampblack residues. Although PAHs on lampblack are tightly sorbed, risk assessments do not account for this reduced availability. A multi-investigator study of 7 oil-gas MGP site soil samples demonstrated that the dermal and ingestion absorption factors are far lower than current default assumptions used in risk assessments. Using these sample-specific absorption factors in standard risk assessment equations increased risk-based cleanup levels by a factor of 72 on average (with a range from 23 to 142 times the default level). The rapidly released fraction of the BaP in each sample, as measured by supercritical fluid extraction, was closely correlated (r2 = 0.96) to these calculated cleanup levels. The weight of evidence developed during this research indicates that the risks posed by PAHs on lampblack are far less than assumed when using default absorption factors and that a tiered evaluation protocol employing chemical analyses, chemical release data, and in vitro bioassays can be used to establish more realistic site-specific criteria.

Multiple external hazards compound level 3 PSA methods research of nuclear power plant

NASA Astrophysics Data System (ADS)

Wang, Handing; Liang, Xiaoyu; Zhang, Xiaoming; Yang, Jianfeng; Liu, Weidong; Lei, Dina

2017-01-01

2011 Fukushima nuclear power plant severe accident was caused by both earthquake and tsunami, which results in large amount of radioactive nuclides release. That accident has caused the radioactive contamination on the surrounding environment. Although this accident probability is extremely small, once such an accident happens that is likely to release a lot of radioactive materials into the environment, and cause radiation contamination. Therefore, studying accidents consequences is important and essential to improve nuclear power plant design and management. Level 3 PSA methods of nuclear power plant can be used to analyze radiological consequences, and quantify risk to the public health effects around nuclear power plants. Based on multiple external hazards compound level 3 PSA methods studies of nuclear power plant, and the description of the multiple external hazards compound level 3 PSA technology roadmap and important technical elements, as well as taking a coastal nuclear power plant as the reference site, we analyzed the impact of off-site consequences of nuclear power plant severe accidents caused by multiple external hazards. At last we discussed the impact of off-site consequences probabilistic risk studies and its applications under multiple external hazards compound conditions, and explained feasibility and reasonableness of emergency plans implementation.

Python-Based Applications for Hydrogeological Modeling

NASA Astrophysics Data System (ADS)

Khambhammettu, P.

2013-12-01

Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Add-on packages supporting fast array computation (numpy), plotting (matplotlib), scientific /mathematical Functions (scipy), have resulted in a powerful ecosystem for scientists interested in exploratory data analysis, high-performance computing and data visualization. Three examples are provided to demonstrate the applicability of the Python environment in hydrogeological applications. Python programs were used to model an aquifer test and estimate aquifer parameters at a Superfund site. The aquifer test conducted at a Groundwater Circulation Well was modeled with the Python/FORTRAN-based TTIM Analytic Element Code. The aquifer parameters were estimated with PEST such that a good match was produced between the simulated and observed drawdowns. Python scripts were written to interface with PEST and visualize the results. A convolution-based approach was used to estimate source concentration histories based on observed concentrations at receptor locations. Unit Response Functions (URFs) that relate the receptor concentrations to a unit release at the source were derived with the ATRANS code. The impact of any releases at the source could then be estimated by convolving the source release history with the URFs. Python scripts were written to compute and visualize receptor concentrations for user-specified source histories. The framework provided a simple and elegant way to test various hypotheses about the site. A Python/FORTRAN-based program TYPECURVEGRID-Py was developed to compute and visualize groundwater elevations and drawdown through time in response to a regional uniform hydraulic gradient and the influence of pumping wells using either the Theis solution for a fully-confined aquifer or the Hantush-Jacob solution for a leaky confined aquifer. The program supports an arbitrary number of wells that can operate according to arbitrary schedules. The python wrapper invokes the underlying FORTRAN layer to compute transient groundwater elevations and processes this information to create time-series and 2D plots.

Web-based technical assistance and training to promote community tobacco control policy change.

PubMed

Young, Walter F; Montgomery, Debbie; Nycum, Colleen; Burns-Martin, Lavon; Buller, David B

2006-01-01

In 1998 the tobacco industry was released of claims that provided monetary relief for states. A significant expansion of tobacco control activity in many states created a need to develop local capacity. Technical assistance and training for new and experienced staff became a significant challenge for tobacco control leadership. In Colorado, this challenge was addressed in part through the development of a technical assistance and training Web site designed for local tobacco control staff and coalition members. Researchers, technical Web site development specialists, state health agency, and state tobacco control coalition staff collaborated to develop, promote, and test the efficacy of this Web site. The work group embodied a range of skills including tobacco control, Web site technical development, marketing, training, and project management. Persistent marketing, updating of Web site content, and institutionalizing it as a principal source of information and training were key to use by community coalition members.

Characterization of the Artemisinin Binding Site for Translationally Controlled Tumor Protein (TCTP) by Bioorthogonal Click Chemistry.

PubMed

Li, Weichao; Zhou, Yiqing; Tang, Guanghui; Xiao, Youli

2016-12-21

Despite the fact that multiple artemisinin-alkylated proteins in Plasmodium falciparum have been identified in recent studies, the alkylation mechanism and accurate binding site of artemisinin-protein interaction have remained elusive. Here, we report the chemical-probe-based enrichment of the artemisinin-binding peptide and characterization of the artemisinin-binding site of P. falciparum translationally controlled tumor protein (TCTP). A peptide fragment within the N-terminal region of TCTP was enriched and found to be alkylated by an artemisinin-derived probe. MS2 fragments showed that artemisinin could alkylate multiple amino acids from Phe12 to Tyr22 of TCTP, which was supported by labeling experiments upon site-directed mutagenesis and computational modeling studies. Taken together, the "capture-and-release" strategy affords consolidated advantages previously unavailable in artemisinin-protein binding site studies, and our results deepened the understanding of the mechanism of protein alkylation via heme-activated artemisinin.

Remedial investigation/feasibility study for the David Witherspoon, Inc., 901 Site, Knoxville, Tennessee: Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-10-01

This remedial investigation (RI)/feasibility study (FS) supports the selection of remedial actions for the David Witherspoon, Inc. 901 Maryville Pike Site in Knoxville, Tennessee. Operations at the site, used as a recycling center, have resulted in past, present, and potential future releases of hazardous substances in to the environment. This Site is a Tennessee Superfund site. A phased approach was planned to (1) gather existing data from previous investigations managed by the Tenn. Dept. of Environment and Conservation; (2) perform a preliminary RI, including risk assessments, and an FS with existing data to identify areas where remedial action may bemore » necessary; (3) gather additional field data to adequately define the nature and extent of risk-based contaminants that present identifiable threats to human and/or ecological receptors; and (4) develop remedial action alternatives to reduce risks to acceptable levels.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haney, Thomas Jay

This report documents the Data Quality Objectives (DQOs) developed for the Idaho National Laboratory (INL) Site ambient air surveillance program. The development of the DQOs was based on the seven-step process recommended “for systematic planning to generate performance and acceptance criteria for collecting environmental data” (EPA 2006). The process helped to determine the type, quantity, and quality of data needed to meet current regulatory requirements and to follow U.S. Department of Energy guidance for environmental surveillance air monitoring design. It also considered the current air monitoring program that has existed at INL Site since the 1950s. The development of themore » DQOs involved the application of the atmospheric dispersion model CALPUFF to identify likely contamination dispersion patterns at and around the INL Site using site-specific meteorological data. Model simulations were used to quantitatively assess the probable frequency of detection of airborne radionuclides released by INL Site facilities using existing and proposed air monitors.« less

Method of injection of onabotulinumtoxinA for chronic migraine: a safe, well-tolerated, and effective treatment paradigm based on the PREEMPT clinical program.

PubMed

Blumenfeld, Andrew; Silberstein, Stephen D; Dodick, David W; Aurora, Sheena K; Turkel, Catherine C; Binder, William J

2010-10-01

Chronic migraine (CM) is a prevalent and disabling neurological disorder. Few prophylactic treatments for CM have been investigated. OnabotulinumtoxinA, which inhibits the release of nociceptive mediators, such as glutamate, substance P, and calcitonin gene-related peptide, has been evaluated in randomized, placebo-controlled studies for the preventive treatment of a variety of headache disorders, including CM. These studies have yielded insight into appropriate patient selection, injection sites, dosages, and technique. Initial approaches used a set of fixed sites for the pericranial injections. However, the treatment approach evolved to include other sites that corresponded to the location of pain and tenderness in the individual patient in addition to the fixed sites. The Phase III REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) injection paradigm uses both fixed and follow-the-pain sites, with additional specific follow-the-pain sites considered depending on individual symptoms. The PREEMPT paradigm for injecting onabotulinumtoxinA has been shown to be safe, well-tolerated, and effective in well-designed, controlled clinical trials and is the evidence-based approach recommended to optimize clinical outcomes for patients with CM. © 2010 American Headache Society.

Corrective Action Decision Document/Closure Report for Corrective Action Unit 106: Area 5, 11 Frenchman Flat Atmospheric Sites, Nevada National Security Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick Matthews and Dawn Peterson

2011-09-01

Corrective Action Unit 106 comprises four corrective action sites (CASs): (1) 05-20-02, Evaporation Pond; (2) 05-23-05, Atmospheric Test Site - Able; (3) 05-45-04, 306 GZ Rad Contaminated Area; (4) 05-45-05, 307 GZ Rad Contaminated Area. The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation that no further corrective action is needed for CAU 106 based on the implementation of corrective actions. The corrective action of clean closure was implemented at CASs 05-45-04 and 05-45-05, while no corrective action was necessary at CASs 05-20-02 and 05-23-05. Corrective action investigation (CAI) activities were performed from October 20,more » 2010, through June 1, 2011, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 106: Areas 5, 11 Frenchman Flat Atmospheric Sites. The approach for the CAI was divided into two facets: investigation of the primary release of radionuclides, and investigation of other releases (mechanical displacement and chemical releases). The purpose of the CAI was to fulfill data needs as defined during the data quality objective (DQO) process. The CAU 106 dataset of investigation results was evaluated based on a data quality assessment. This assessment demonstrated the dataset is complete and acceptable for use in fulfilling the DQO data needs. Investigation results were evaluated against final action levels (FALs) established in this document. A radiological dose FAL of 25 millirem per year was established based on the Industrial Area exposure scenario (2,250 hours of annual exposure). The only radiological dose exceeding the FAL was at CAS 05-45-05 and was associated with potential source material (PSM). It is also assumed that additional PSM in the form of depleted uranium (DU) and DU-contaminated debris at CASs 05-45-04 and 05-45-05 exceed the FAL. Therefore, corrective actions were undertaken at these CASs that consisted of removing PSM and collecting verification samples. Results of verification samples show that remaining soil does not contain contamination exceeding the FALs. Therefore, the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) provides the following recommendations: (1) No further corrective actions are necessary for CAU 106. (2) A Notice of Completion to NNSA/NSO is requested from the Nevada Division of Environmental Protection for closure of CAU 106. (3) Corrective Action Unit 106 should be moved from Appendix III to Appendix IV of the FFACO.« less

Identifying past petroleum exploration related drill cutting releases and influences on the marine environment and benthic foraminiferal communities, Goliat Field, SW Barents Sea, Norway.

PubMed

Aagaard-Sørensen, Steffen; Junttila, Juho; Dijkstra, Noortje

2018-04-01

The present multiproxy investigation of marine sediment cores aims at: 1) Identifying dispersion of petroleum exploration related drill cutting releases within the Goliat Field, Barents Sea in 2006/07 and 2) Assessing past and present influence of drill cuttings on the marine environment. The cores were recovered 5, 30, 60, 125 and 250m from the drill site in the eastward downstream direction. Downstream dispersion of drill cuttings is evaluated by examining sediment grain size distribution and barium (Ba), heavy metal, total organic carbon and sulphur concentrations. Dispersion of drill cuttings was limited to <125m east from the drill site. Influence of drill cutting releases on the marine environment is assessed via microfaunal analysis of primarily calcareous benthic foraminifera. The findings suggest contemporaneous physical smothering at ≤30m from the drill site, with a natural fauna reestablishing after drilling cessation indicating no long-term effect of drill cutting releases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Plutonium release from the 903 pad at Rocky Flats.

PubMed

Mongan, T R; Ripple, S R; Winges, K D

1996-10-01

The Colorado Department of Public Health and Environment (CDH) sponsored a study to reconstruct contaminant doses to the public from operations at the Rocky Flats nuclear weapons plant. This analysis of the accidental release of plutonium from the area known as the 903 Pad is part of the CDH study. In the 1950's and 1960's, 55-gallon drums of waste oil contaminated with plutonium, and uranium were stored outdoors at the 903 Pad. The drums corroded, leaking contaminated oil onto soil subsequently carried off-site by the wind. The plutonium release is estimated using environmental data from the 1960's and 1970's and an atmospheric transport model for fugitive dust. The best estimate of total plutonium release to areas beyond plant-owned property is about 0.26 TBq (7 Ci). Off-site airborne concentrations and deposition of plutonium are estimated for dose calculation purposes. The best estimate of the highest predicted off-site effective dose is approximately 72 microSv (7.2 mrem).

Developments in the use of nanocapsules in oncology

PubMed Central

Yurgel, V.; Collares, T.; Seixas, F.

2013-01-01

The application of nanotechnology to medicine can provide important benefits, especially in oncology, a fact that has resulted in the emergence of a new field called Nanooncology. Nanoparticles can be engineered to incorporate a wide variety of chemotherapeutic or diagnostic agents. A nanocapsule is a vesicular system that exhibits a typical core-shell structure in which active molecules are confined to a reservoir or within a cavity that is surrounded by a polymer membrane or coating. Delivery systems based on nanocapsules are usually transported to a targeted tumor site and then release their contents upon change in environmental conditions. An effective delivery of the therapeutic agent to the tumor site and to the infiltrating tumor cells is difficult to achieve in many cancer treatments. Therefore, new devices are being developed to facilitate intratumoral distribution, to protect the active agent from premature degradation and to allow its sustained and controlled release. This review focuses on recent studies on the use of nanocapsules for cancer therapy and diagnosis. PMID:23802234

Ca2+-induced Ca2+ Release Phenomena in Mammalian Sympathetic Neurons Are Critically Dependent on the Rate of Rise of Trigger Ca2+

PubMed Central

Hernández-Cruz, Arturo; Escobar, Ariel L.; Jiménez, Nicolás

1997-01-01

The role of ryanodine-sensitive intracellular Ca2+ stores present in nonmuscular cells is not yet completely understood. Here we examine the physiological parameters determining the dynamics of caffeine-induced Ca2+ release in individual fura-2–loaded sympathetic neurons. Two ryanodine-sensitive release components were distinguished: an early, transient release (TR) and a delayed, persistent release (PR). The TR component shows refractoriness, depends on the filling status of the store, and requires caffeine concentrations ≥10 mM. Furthermore, it is selectively suppressed by tetracaine and intracellular BAPTA, which interfere with Ca2+-mediated feedback loops, suggesting that it constitutes a Ca2+-induced Ca2+-release phenomenon. The dynamics of release is markedly affected when Sr2+ substitutes for Ca2+, indicating that Sr2+ release may operate with lower feedback gain than Ca2+ release. Our data indicate that when the initial release occurs at an adequately fast rate, Ca2+ triggers further release, producing a regenerative response, which is interrupted by depletion of releasable Ca2+ and Ca2+-dependent inactivation. A compartmentalized linear diffusion model can reproduce caffeine responses: When the Ca2+ reservoir is full, the rapid initial Ca2+ rise determines a faster occupation of the ryanodine receptor Ca2+ activation site giving rise to a regenerative release. With the store only partially loaded, the slower initial Ca2+ rise allows the inactivating site of the release channel to become occupied nearly as quickly as the activating site, thereby suppressing the initial fast release. The PR component is less dependent on the store's Ca2+ content. This study suggests that transmembrane Ca2+ influx in rat sympathetic neurons does not evoke widespread amplification by CICR because of its inability to raise [Ca2+] near the Ca2+ release channels sufficiently fast to overcome their Ca2+-dependent inactivation. Conversely, caffeine-induced Ca2+ release can undergo considerable amplification especially when Ca2+ stores are full. We propose that the primary function of ryanodine-sensitive stores in neurons and perhaps in other nonmuscular cells, is to emphasize subcellular Ca2+ gradients resulting from agonist-induced intracellular release. The amplification gain is dependent both on the agonist concentration and on the filling status of intracellular Ca2+ stores. PMID:9041445

Closure Report for Corrective Action Unit 536: Area 3 Release Site, Nevada Test Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

NSTec Environmental Restoration

Corrective Action Unit (CAU) 536 is located in Area 3 of the Nevada Test Site. CAU 536 is listed in the Federal Facility Agreement and Consent Order of 1996 as Area 3 Release Site, and comprises a single Corrective Action Site (CAS): {sm_bullet} CAS 03-44-02, Steam Jenny Discharge The Nevada Division of Environmental Protection (NDEP)-approved corrective action alternative for CAS 03-44-02 is clean closure. Closure activities included removing and disposing of total petroleum hydrocarbon (TPH)- and polyaromatic hydrocarbon (PAH)-impacted soil, soil impacted with plutonium (Pu)-239, and concrete pad debris. CAU 536 was closed in accordance with the NDEP-approved CAU 536more » Corrective Action Plan (CAP), with minor deviations as approved by NDEP. The closure activities specified in the CAP were based on the recommendations presented in the CAU 536 Corrective Action Decision Document (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, 2004). This Closure Report documents CAU 536 closure activities. During closure activities, approximately 1,000 cubic yards (yd3) of hydrocarbon waste in the form of TPH- and PAH-impacted soil and debris, approximately 8 yd3 of Pu-239-impacted soil, and approximately 100 yd3 of concrete debris were generated, managed, and disposed of appropriately. Additionally, a previously uncharacterized, buried drum was excavated, removed, and disposed of as hydrocarbon waste as a best management practice. Waste minimization techniques, such as the utilization of laboratory analysis to characterize and classify waste streams, were employed during the performance of closure« less

Time and pH dependent colon specific, pulsatile delivery of theophylline for nocturnal asthma.

PubMed

Mastiholimath, V S; Dandagi, P M; Jain, S Samata; Gadad, A P; Kulkarni, A R

2007-01-02

In this study, investigation of an oral colon specific, pulsatile device to achieve time and/or site specific release of theophylline, based on chronopharmaceutical consideration. The basic design consists of an insoluble hard gelatin capsule body, filled with eudragit microcapsules of theophylline and sealed with a hydrogel plug. The entire device was enteric coated, so that the variability in gastric emptying time can be overcome and a colon-specific release can be achieved. The theophylline microcapsules were prepared in four batches, with Eudragit L-100 and S-100 (1:2) by varying drug to polymer ratio and evaluated for the particle size, drug content and in vitro release profile and from the obtained results; one better formulation was selected for further fabrication of pulsatile capsule. Different hydrogel polymers were used as plugs, to maintain a suitable lag period and it was found that the drug release was controlled by the proportion of polymers used. In vitro release studies of pulsatile device revealed that, increasing the hydrophilic polymer content resulted in delayed release of theophylline from microcapsules. The gamma scintigraphic study pointed out the capability of the system to release drug in lower parts of GIT after a programmed lag time for nocturnal asthma. Programmable pulsatile, colon-specific release has been achieved from a capsule device over a 2-24h period, consistent with the demands of chronotherapeutic drug delivery.

Release of free amino acids upon oxidation of peptides and proteins by hydroxyl radicals.

PubMed

Liu, Fobang; Lai, Senchao; Tong, Haijie; Lakey, Pascale S J; Shiraiwa, Manabu; Weller, Michael G; Pöschl, Ulrich; Kampf, Christopher J

2017-03-01

Hydroxyl radical-induced oxidation of proteins and peptides can lead to the cleavage of the peptide, leading to a release of fragments. Here, we used high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) and pre-column online ortho-phthalaldehyde (OPA) derivatization-based amino acid analysis by HPLC with diode array detection and fluorescence detection to identify and quantify free amino acids released upon oxidation of proteins and peptides by hydroxyl radicals. Bovine serum albumin (BSA), ovalbumin (OVA) as model proteins, and synthetic tripeptides (comprised of varying compositions of the amino acids Gly, Ala, Ser, and Met) were used for reactions with hydroxyl radicals, which were generated by the Fenton reaction of iron ions and hydrogen peroxide. The molar yields of free glycine, aspartic acid, asparagine, and alanine per peptide or protein varied between 4 and 55%. For protein oxidation reactions, the molar yields of Gly (∼32-55% for BSA, ∼10-21% for OVA) were substantially higher than those for the other identified amino acids (∼5-12% for BSA, ∼4-6% for OVA). Upon oxidation of tripeptides with Gly in C-terminal, mid-chain, or N-terminal positions, Gly was preferentially released when it was located at the C-terminal site. Overall, we observe evidence for a site-selective formation of free amino acids in the OH radical-induced oxidation of peptides and proteins, which may be due to a reaction pathway involving nitrogen-centered radicals.

Population dose commitments due to radioactive releases from nuclear power plant sites in 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.; Peloquin, R.A.

Population radiation dose commitments have been estimated from reported radionuclide releases from commercial power reactors operating during 1980. In addition doses derived from the shutdown reactors at the Three Mile Island site were included. Fifty-year dose commitments from a one-year exposure were calculated from both liquid and atmospheric releases for four population groups (infant, child, teen-ager and adult) residing between 2 and 80 km from each site. This report tabulates the results of these calculations, showing the dose commitments for both liquid and airborne pathways for each age group and organ. Also included for each site is a histogram showingmore » the fraction of the total population within 2 to 80 km around each site receiving various average dose commitments from the airborne pathways. The total dose commitment from both liquid and airborne pathways ranged from a high of 40 person-rem to a low of 0.02 person-rem with an arithmetic mean of 4 person-rem. The total population dose for all sites was estimated at 180 person-rem for the 96 million people considered at risk.« less

Hydraulic architecture and photosynthetic capacity as constraints on release from suppression in Douglas-fir and western hemlock.

PubMed

Renninger, Heidi J; Meinzer, Frederick C; Gartner, Barbara L

2007-01-01

We compared hydraulic architecture, photosynthesis and growth in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a shade-intolerant species, and western hemlock (Tsuga heterophylla (Raf.) Sarg.), a shade-tolerant species, to study the temporal pattern of release from suppressive shade. In particular, we sought to determine whether hydraulic architecture or photosynthetic capacity is most important in constraining release. The study was conducted at two sites with mixed stands of 10- to 20-year-old Douglas-fir and western hemlock. At one site, the stand had been thinned allowing release of the understory trees, whereas at the other site, the stand remained unthinned. Douglas-fir had lower height growth (from 1998-2003) and lower relative height growth (height growth from 1998 to 2003/height in 1998) than western hemlock. However, relative height growth of released versus suppressed trees was higher in Douglas-fir (130%) than in western hemlock (65%), indicating that, although absolute height growth was less, Douglas-fir did release from suppression. Release seemed to be constrained initially by a limited photosynthetic capacity in both species. Five years after release, Douglas-fir trees had 14 times the leaf area and 1.5 times the leaf nitrogen concentration (N (area)) of suppressed trees. Needles of released western hemlock trees had about twice the maximum assimilation rate (A (max)) at ambient [CO(2)] as needles of suppressed trees and exhibited no photoinhibition at the highest irradiances. After release, trees increased in leaf area, leaf N concentration and overall photosynthetic capacity. Subsequently, hydraulic architecture appeared to constrain release in Douglas-fir and, to a lesser extent, in western hemlock. Released trees had significantly less negative foliar delta(13)C values than suppressed trees and showed a positive relationship between leaf area:sapwood area ratio (A (L)/A (S)) and delta(13)C, suggesting that trees with more leaf area for a given sapwood area experienced a stomatal limitation on carbon gain. Nonetheless, these changes had no significant effects on leaf specific conductivities of suppressed versus released trees of either species, but leaf specific root conductance was significantly lower in released Douglas-fir.

Roles of survival and dispersal in reintroduction success of Griffon vulture (Gyps fulvus).

PubMed

Le Gouar, Pascaline; Robert, Alexandre; Choisy, Jean-Pierre; Henriquet, Sylvain; Lecuyer, Philippe; Tessier, Christian; Sarrazin, François

2008-06-01

The success of reintroduction programs greatly depends on the amount of mortality and dispersal of the released individuals. Although local environmental pressures are likely to play an important role in these processes, they have rarely been investigated because of the lack of spatial replicates of reintroduction. In the present study, we analyzed a 25-year data set encompassing 272 individuals released in five reintroduction programs of Griffon Vultures (Gyps fulvus) in France to examine the respective roles of survival and dispersal in program successes and failures. We use recent developments in multi-strata capture-recapture models to take into account tag loss in survival estimates and to consider and estimate dispersal among release areas. We also examined the effects of sex, age, time, area, and release status on survival, and we tested whether dispersal patterns among release areas were consistent with habitat selection theories. Results indicated that the survival of released adults was reduced during the first year after release, with no difference between sexes. Taking into account local observations only, we found that early survival rates varied across sites. However when we distinguished dispersal from mortality, early survival rates became equal across release sites. It thus appears that among reintroduction programs difference in failure and success was due to differential dispersal among release sites. We revealed asymmetrical patterns of dispersal due to conspecific attraction: dispersers selected the closest and the largest population. We showed that mortality can be homogeneous from one program to another while, on the contrary, dispersal is highly dependent on the matrix of established populations. Dispersal behavior is thus of major interest for metapopulation restoration and should be taken into account in planning reintroduction designs.

Kauai Test Facility hazards assessment document

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swihart, A

1995-05-01

The Department of Energy Order 55003A requires facility-specific hazards assessment be prepared, maintained, and used for emergency planning purposes. This hazards assessment document describes the chemical and radiological hazards associated with the Kauai Test Facility, Barking Sands, Kauai, Hawaii. The Kauai Test Facility`s chemical and radiological inventories were screened according to potential airborne impact to onsite and offsite individuals. The air dispersion model, ALOHA, estimated pollutant concentrations downwind from the source of a release, taking into consideration the toxicological and physical characteristics of the release site, the atmospheric conditions, and the circumstances of the release. The greatest distance to themore » Early Severe Health Effects threshold is 4.2 kilometers. The highest emergency classification is a General Emergency at the {open_quotes}Main Complex{close_quotes} and a Site Area Emergency at the Kokole Point Launch Site. The Emergency Planning Zone for the {open_quotes}Main Complex{close_quotes} is 5 kilometers. The Emergency Planning Zone for the Kokole Point Launch Site is the Pacific Missile Range Facility`s site boundary.« less

Formulation and evaluation of chitosan/polyethylene oxide nanofibers loaded with metronidazole for local infections.

PubMed

Zupančič, Špela; Potrč, Tanja; Baumgartner, Saša; Kocbek, Petra; Kristl, Julijana

2016-12-01

Nanofibers combined with an antimicrobial represent a powerful strategy for treatment of various infections. Local infections usually have a low fluid volume available for drug release, whereas pharmacopoeian dissolution tests include a much larger receptor volume. Therefore, the development of novel drug-release methods that more closely resemble the in-vivo conditions is necessary. We first developed novel biocompatible and biodegradable chitosan/polyethylene oxide nanofibers using environmentally friendly electrospinning of aqueous polymer solutions, with the inclusion of the antimicrobial metronidazole. Here, the focus is on the characterization of these nanofibers, which have high potential for bioadhesion and retention at the site of application. These can be used where prolonged retention of the delivery system at an infected target site is needed. Drug release was studied using three in-vitro methods: a dissolution apparatus (Apparatus 1 of the European Pharmacopoeia), vials, and a Franz diffusion cell. In contrast to other studies, here the Franz diffusion cell method was modified to introduce a small volume of medium with the nanofibers in the donor compartment, where the nanofibers swelled, eroded, and released the metronidazole, which then diffused into the receptor compartment. This set-up with nanofibers in a limited amount of medium released the drug more slowly compared to the other two in-vitro methods that included larger volumes of medium. These findings show that drug release from nanofibers strongly depends on the release method used. Therefore, in-vitro test methods should closely resemble the in-vivo conditions for more accurate prediction of drug release at a therapeutic site. Copyright © 2016 Elsevier B.V. All rights reserved.

Base Release and Modification in Solid-Phase DNA Exposed to Low-Energy Electrons.

PubMed

Choofong, Surakarn; Cloutier, Pierre; Sanche, Léon; Wagner, J Richard

2016-11-01

Ionization generates a large number of secondary low-energy electrons (LEEs) with a most probable energy of approximately 10 eV, which can break DNA bonds by dissociative electron attachment (DEA) and lead to DNA damage. In this study, we investigated radiation damage to dry DNA induced by X rays (1.5 keV) alone on a glass substrate or X rays combined with extra LEEs (average energy of 5.8 eV) emitted from a tantalum (Ta) substrate under an atmosphere of N 2 and standard ambient conditions of temperature and pressure. The targets included calf-thymus DNA and double-stranded synthetic oligonucleotides. We developed analytical methods to measure the release of non-modified DNA bases from DNA and the formation of several base modifications by LC-MS/MS with isotopic dilution for precise quantification. The results show that the yield of non-modified bases as well as base modifications increase by 20-30% when DNA is deposited on a Ta substrate compared to that on a glass substrate. The order of base release (Gua > Ade > Thy ∼ Cyt) agrees well with several theoretical studies indicating that Gua is the most susceptible site toward sugar-phosphate cleavage. The formation of DNA damage by LEEs is explained by DEA leading to the release of non-modified bases involving the initial cleavage of N1-C1', C3'-O3' or C5'-O5' bonds. The yield of base modifications was lower than the release of non-modified bases. The main LEE-induced base modifications include 5,6-dihydrothymine (5,6-dHT), 5,6-dihydrouracil (5-dHU), 5-hydroxymethyluracil (5-HmU) and 5-formyluracil (5-ForU). The formation of base modifications by LEEs can be explained by DEA and cleavage of the C-H bond of the methyl group of Thy (giving 5-HmU and 5-ForU) and by secondary reactions of H atoms and hydride anions that are generated by primary LEE reactions followed by subsequent reaction with Cyt and Thy (giving 5,6-dHU and 5,6-dHT).

Predawn Leaf Water Potential of Oak-Hickory Forest at Missouri Ozark (MOFLUX) Site: 2004-2017

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pallardy, S.G.; Gu, L.; Wood, J.D.

Measurements of predawn leaf water potential (PLWP) have been made at weekly to biweekly intervals during the 2004 to 2017 growing seasons of the second-growth upland oak-hickory forests at the Missouri Ozark AmeriFlux (MOFLUX) site. The MOFLUX site is located in the University of Missouri Baskett Wildlife Research area (BWREA), situated in the Ozark Border Region of central Missouri, USA. Data Release Notes: The first release of PLWP data for MOFLUX covered the range of June 18, 2004 through October 18, 2014 (Pallardy et al., 2015). This second release appends data through October 3, 2017. • There were no changesmore » to the previously released data and the format and structure of this release are the same. • The data citation has been updated. o Addition of author J.D. Wood o Year published is now 2018 o Update of title for extended date range (2004-2017) o Change of publisher (Oak Ridge National Laboratory, TES SFA) o No change to the DOI (10.3334/CDIAC/ornlsfa.004) • Please use the updated citation when referencing any or all the PLWP data.« less

Illuminating pathways of forest nutrient provision: relative release from soil mineral and organic pools

NASA Astrophysics Data System (ADS)

Hauser, E.; Billings, S. A.

2017-12-01

Depletion of geogenic nutrients during soil weathering can prompt vegetation to rely on other sources, such as organic matter (OM) decay, to meet growth requirements. Weathered soils also tend to permit deep rooting, a phenomenon sometimes attributed to vegetation foraging for geogenic nutrients. This study examines the extent to which OM recycling provides nutrients to vegetation growing in soils with diverse weathering states. We thus address the fundamental problem of how forest vegetation obtains sufficient nutrition to support productivity despite wide variation in soils' nutrient contents. We hypothesized that vegetation growing on highly weathered soils relies on nutrients released from OM decay to a greater extent than vegetation growing on less weathered, more nutrient-rich substrates. For four mineralogically diverse Critical Zone Observatories (CZO) and Critical Zone Exploratory Network sites, we calculated weathering indices and approximated vegetation nutrient demand and nutrient release from OM decay. We also measured nutrient release rates from OM decay at each site. We then assessed the relationship between degree of soil weathering and the estimated fraction of nutrient demand satisfied by OM derived nutrients. Results are consistent with our hypothesis. The chemical index of alteration (CIA), a weathering index that increases in value with mineral depletion, varies predictably from 90 at the highly weathered Calhoun CZO to 60 at the Catalina CZO, where soils are more recently developed. Estimates of rates of K release from OM decay increase with CIA values. The highest release rate is 2.4 gK m-2 y-1 at Calhoun, accounting for 30% of annual vegetation K uptake; at Catalina, less than 0.5 gm-2 y-1 K is released, meeting 14% of vegetation demand. CIA also co-varies with rooting depth across sites: the deepest roots at the Calhoun sites are growing in soils with the highest CIA values, while the deepest roots at Catalina sites are growing in soils with much lower CIA values. Thus, provision of plant-available nutrients from OM decay appears greater at more weathered sites, and dominant nutrient sources accessed by deep roots (OM- vs. rock-derived) may vary predictably with soil weathering stage. On-going incubations will permit us to assess these relationships for multiple geogenic nutrients.

Short-Term Facilitation at a Detonator Synapse Requires the Distinct Contribution of Multiple Types of Voltage-Gated Calcium Channels.

PubMed

Chamberland, Simon; Evstratova, Alesya; Tóth, Katalin

2017-05-10

Neuronal calcium elevations are shaped by several key parameters, including the properties, density, and the spatial location of voltage-gated calcium channels (VGCCs). These features allow presynaptic terminals to translate complex firing frequencies and tune the amount of neurotransmitter released. Although synchronous neurotransmitter release relies on both P/Q- and N-type VGCCs at hippocampal mossy fiber-CA3 synapses, the specific contribution of VGCCs to calcium dynamics, neurotransmitter release, and short-term facilitation remains unknown. Here, we used random-access two-photon calcium imaging together with electrophysiology in acute mouse hippocampal slices to dissect the roles of P/Q- and N-type VGCCs. Our results show that N-type VGCCs control glutamate release at a limited number of release sites through highly localized Ca 2+ elevations and support short-term facilitation by enhancing multivesicular release. In contrast, Ca 2+ entry via P/Q-type VGCCs promotes the recruitment of additional release sites through spatially homogeneous Ca 2+ elevations. Altogether, our results highlight the specialized contribution of P/Q- and N-types VGCCs to neurotransmitter release. SIGNIFICANCE STATEMENT In presynaptic terminals, neurotransmitter release is dynamically regulated by the transient opening of different types of voltage-gated calcium channels. Hippocampal giant mossy fiber terminals display extensive short-term facilitation during repetitive activity, with a large several fold postsynaptic response increase. Though, how giant mossy fiber terminals leverage distinct types of voltage-gated calcium channels to mediate short-term facilitation remains unexplored. Here, we find that P/Q- and N-type VGCCs generate different spatial patterns of calcium elevations in giant mossy fiber terminals and support short-term facilitation through specific participation in two mechanisms. Whereas N-type VGCCs contribute only to the synchronization of multivesicular release, P/Q-type VGCCs act through microdomain signaling to recruit additional release sites. Copyright © 2017 the authors 0270-6474/17/374913-15$15.00/0.

3,4-Methylenedioxyamphetamine (MDA) analogues exhibit differential effects on synaptosomal release of 3H-dopamine and 3H-5-hydroxytryptamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKenna, D.J.; Guan, X.M.; Shulgin, A.T.

1991-03-01

The effect of various analogues of the neurotoxic amphetamine derivative, MDA (3,4-methylenedioxyamphetamine) on carrier-mediated, calcium-independent release of 3H-5-HT and 3H-DA from rat brain synaptosomes was investigated. Both enantiomers of the neurotoxic analogues MDA and MDMA (3,4-methylenedioxymethamphetamine) induce synaptosomal release of 3H-5-HT and 3H-DA in vitro. The release of 3H-5-HT induced by MDMA is partially blocked by 10(-6) M fluoxetine. The (+) enantiomers of both MDA and MDMA are more potent than the (-) enantiomers as releasers of both 3H-5-HT and 3H-DA. Eleven analogues, differing from MDA with respect to the nature and number of ring and/or side chain substituents, alsomore » show some activity in the release experiments, and are more potent as releasers of 3H-5-HT than of 3H-DA. The amphetamine derivatives {plus minus}fenfluramine, {plus minus}norfenfluramine, {plus minus}MDE, {plus minus}PCA, and d-methamphetamine are all potent releasers of 3H-5-HT and show varying degrees of activity as 3H-DA releasers. The hallucinogen DOM does not cause significant release of either 3H-monoamine. Possible long-term serotonergic neurotoxicity was assessed by quantifying the density of 5-HT uptake sites in rats treated with multiple doses of selected analogues using 3H-paroxetine to label 5-HT uptake sites. In the neurotoxicity study of the compounds investigated, only (+)MDA caused a significant loss of 5-HT uptake sites in comparison to saline-treated controls. These results are discussed in terms of the apparent structure-activity properties affecting 3H-monoamine release and their possible relevance to neurotoxicity in this series of MDA congeners.« less

Field-lysimeter and Column Studies As Complementary Survey Tools For Monitored Natural Attenuation (mna)

NASA Astrophysics Data System (ADS)

Totsche, K. U.; Hensel, D.; Jann, S.; Jaesche, P.; Kögel-Knabner, I.; Scheibke, R.

The contamination of the unsaturated soil zone with organic pollutants (PAH, BTEX, PCB, Phenols, etc.) and pollutant mixtures, e.g. light/dense non-aqueous phase liq- uids (L/D-NAPLs), represents a specific challenge for sanitation and remediation of contaminated sites. Monitored natural attenuation as an alternative option for remedi- ation of such sites requires (1) the proof of an effective pollutant reduction potential and (2) the proof that a further spreading of the contaminants and their potentially toxic metabolites is minimized to an acceptable minimum concentration level. These demands apply equally likely to contaminated soil and groundwater environments. However, a major problem arises when the task is to monitor the release and transport of contaminants within the unsaturated soil zone over a longer period (> 10 years) of time at an expenditure as small as possible. The aim of our presentation is to employ and test a survey technique to monitor pollutant release and redistribution within the unsaturated soil zone in the context of MNA. The proposed technique is based on the combination of laboratory-column and field-lysimeter studies. The first is used to ac- quire knowledge on the governing processes, the latter is used to monitor release and transport of the contaminants.

Minimizing the cost of translocation failure with decision-tree models that predict species' behavioral response in translocation sites.

PubMed

Ebrahimi, Mehregan; Ebrahimie, Esmaeil; Bull, C Michael

2015-08-01

The high number of failures is one reason why translocation is often not recommended. Considering how behavior changes during translocations may improve translocation success. To derive decision-tree models for species' translocation, we used data on the short-term responses of an endangered Australian skink in 5 simulated translocations with different release conditions. We used 4 different decision-tree algorithms (decision tree, decision-tree parallel, decision stump, and random forest) with 4 different criteria (gain ratio, information gain, gini index, and accuracy) to investigate how environmental and behavioral parameters may affect the success of a translocation. We assumed behavioral changes that increased dispersal away from a release site would reduce translocation success. The trees became more complex when we included all behavioral parameters as attributes, but these trees yielded more detailed information about why and how dispersal occurred. According to these complex trees, there were positive associations between some behavioral parameters, such as fight and dispersal, that showed there was a higher chance, for example, of dispersal among lizards that fought than among those that did not fight. Decision trees based on parameters related to release conditions were easier to understand and could be used by managers to make translocation decisions under different circumstances. © 2015 Society for Conservation Biology.

An effective treatment approach of DPP-IV inhibitor encapsulated polymeric nanoparticles conjugated with anti-CD-4 mAb for type 1 diabetes.

PubMed

Thondawada, Mahesh; Wadhwani, Ashish Devidas; S Palanisamy, Dhanabal; Rathore, Hanumant Singh; Gupta, Ramesh C; Chintamaneni, Pavan Kumar; Samanta, Malay K; Dubala, Anil; Varma, Sameer; Krishnamurthy, Praveen T; Gowthamarajan, Kuppusamy

2018-07-01

Nanotechnology based biomedical approaches and surface modification techniques made it easier for targeting specific site and improving the treatment efficacy. The present study reports on targeted polymeric nanoparticles conjugated with antibody as a site-specific carrier system for effective treatment of type 1 diabetes. Sitagliptin (SP)-loaded Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP) were prepared by nanoprecipitation cum solvent evaporation method and were characterized in terms of morphology, size, surface charge, and entrapment efficiency. Optimized batch demonstrated a particle size of 105.24 nm, with significant entrapment efficacy. In vitro release studies exhibited a controlled release pattern of 67.76 ± 1.30% in 24 h, and a maximum of 96.59 ± 1.26% at the end of 48 h. Thiol groups were introduced on the surface of SP-NPs whose concentration on SP-NPs was 27 ± 2.6 mmol/mol PLGA-NPs, anti-CD4 antibody clone Q4120 was conjugated to the thiolated SP-NPs via a sulfo-MBS cross-linker, ∼70% conjugation was observed. The in vitro cytotoxicity studies performed on RIN-5 F cells for mAb-SP-NPs presented an IC 50 of 76 µg/mL, and the insulin release assay had revealed an increased release at 5.15 ± 0.16 IU/mL. The results indicate that mAb-SP-NPs allowed a controlled release of SP and thereby produced insulin levels comparable with control. Therefore, mAb-SP-NPs system appears to be effective in the treatment of auto immune diabetes, subject to further analysis.

Columbia River Component Data Evaluation Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

C.S. Cearlock

2006-08-02

The purpose of the Columbia River Component Data Compilation and Evaluation task was to compile, review, and evaluate existing information for constituents that may have been released to the Columbia River due to Hanford Site operations. Through this effort an extensive compilation of information pertaining to Hanford Site-related contaminants released to the Columbia River has been completed for almost 965 km of the river.

Release of elements to natural water from sediments of Lake Roosevelt, Washington, USA

USGS Publications Warehouse

Paulson, Anthony J.; Cox, Stephen E.

2007-01-01

Reservoir sediments from Lake Roosevelt (WA, USA) that were contaminated with smelter waste discharged into the Columbia River (BC, Canada) were examined using three measures of elemental release reflecting varying degrees of physical mixing and time scales. Aqueous concentrations of Cd, Cu, Pb, and Zn in the interstitial water of reservoir sediments, in the gently stirred overlying waters of incubated sediment cores, and in supernatants of aggressively tumbled slurries of reservoir sediments generally were higher than the concentrations from a reference site. When compared to chronic water-quality criteria, all three measures of release suggest that slag-contaminated sediments near the U.S.-Canadian border are potentially toxic as a result of Cu release and Pb release in two of the three measures. All three measures of Cd release suggest potential toxicity for one site farther down the reservoir, probably contaminated as a result of transport and adsorption of Cd from smelter liquid waste. Releases of Zn and As did not appear to be potentially toxic. Carbonate geochemistry indirectly affects the potential toxicity by increasing water hardness.

Empirical calibration of uranium releases in the terrestrial environment of nuclear fuel cycle facilities.

PubMed

Pourcelot, Laurent; Masson, Olivier; Saey, Lionel; Conil, Sébastien; Boulet, Béatrice; Cariou, Nicolas

2017-05-01

In the present paper the activity of uranium isotopes measured in plants and aerosols taken downwind of the releases of three nuclear fuel settlements was compared between them and with the activity measured at remote sites. An enhancement of 238 U activity as well as 235 U/ 238 U anomalies and 236 U are noticeable in wheat, grass, tree leaves and aerosols taken at the edge of nuclear fuel settlements, which show the influence of uranium chronic releases. Further plants taken at the edge of the studied sites and a few published data acquired in the same experimental conditions show that the 238 U activity in plants is influenced by the intensity of the U atmospheric releases. Assuming that 238 U in plant is proportional to the intensity of the releases, we proposed empirical relationships which allow to characterize the chronic releases on the ground. Other sources of U contamination in plants such as accidental releases and "delayed source" of uranium in soil are also discussed in the light of uranium isotopes signatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

DOE Office of Scientific and Technical Information (OSTI.GOV)

WEBER RA

2009-01-16

The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. Themore » first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there is sufficient supernatant on top of the saturated solids such that gas-bearing solids have the potential energy required to break up the material and release gas. Tanks that are not waste group C tanks and that have an energy ratio < 3.0 do not have sufficient potential energy to break up material and release gas and are assigned to waste group B. These tanks are considered to represent a potential induced flammable gas release hazard, but no spontaneous buoyant displacement flammable gas release hazard. Tanks that are not waste group C tanks and have an energy ratio {ge} 3.0, but that pass the third criterion (buoyancy ratio < 1.0, see below) are also assigned to waste group B. Even though the designation as a waste group B (or A) tank identifies the potential for an induced flammable gas release hazard, the hazard only exists for specific operations that can release the retained gas in the tank at a rate and quantity that results in reaching 100% of the lower flammability limit in the tank headspace. The identification and evaluation of tank farm operations that could cause an induced flammable gas release hazard in a waste group B (or A) tank are included in other documents. The third criterion is the buoyancy ratio. This criterion addresses tanks that are not waste group C double-shell tanks and have an energy ratio {ge} 3.0. For these double-shell tanks, the buoyancy ratio considers whether the saturated solids can retain sufficient gas to exceed neutral buoyancy relative to the supernatant layer and therefore have buoyant displacement gas release events. If the buoyancy ratio is {ge} 1.0, that double-shell tank is assigned to waste group A. These tanks are considered to have a potential spontaneous buoyant displacement flammable gas release hazard in addition to a potential induced flammable gas release hazard. This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 8 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs.« less

A dual pH/thermal responsive nanocarrier for combined chemo-thermotherapy based on a copper-doxorubicin complex and gold nanorods

NASA Astrophysics Data System (ADS)

Lei, Mingzhu; Ma, Man; Pang, Xiaojuan; Tan, Fengping; Li, Nan

2015-09-01

The development of treatment protocols that results in a complete response to chemotherapy has been hampered by low efficacy and systemic toxicity. Here, we created a pH sensitive copper-doxorubicin complex within the core of temperature-sensitive liposomes to maintain the stability during blood circulation and trigger Dox release in the tumor site. Synergistically, we also rationally applied gold nanorods (AuNRs) coupled with near-infrared (NIR) field strength to produce a precise and localized temperature, which not only remotely controlled the drug release but also directly destroyed the tumor, to enhance the therapeutic efficacy. As expected, the in vitro release studies showed that the drug release from CuDox-TSLs (Copper ion mediated Doxorubicin loading-Temperature Sensitive Liposomes) was both pH-dependent and temperature-dependent. Furthermore, MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assays showed that CuDox-TSLs combined with AuNRs exhibited a closer antiproliferative activity to free Dox in MCF-7 cells. The efficient intracellular Dox release from CuDox-TSLs toward the tumor cells further confirmed the anti-tumor effect. Moreover, the in vivo imaging and biodistribution studies revealed that CuDox-TSLs combined with AuNRs could actively target the tumor site. In addition, the therapeutic studies in MCF-7 nude mice exhibited CuDox-TSLs plus AuNRs in combination with NIR irradiation inhibited tumor growth to a great extent and possessed much lower side effects, which were further confirmed by systemic histological analyses. All detailed evidence suggested a considerable potential of CuDox-TSLs combined with AuNRs for treatment of metastatic cancer.The development of treatment protocols that results in a complete response to chemotherapy has been hampered by low efficacy and systemic toxicity. Here, we created a pH sensitive copper-doxorubicin complex within the core of temperature-sensitive liposomes to maintain the stability during blood circulation and trigger Dox release in the tumor site. Synergistically, we also rationally applied gold nanorods (AuNRs) coupled with near-infrared (NIR) field strength to produce a precise and localized temperature, which not only remotely controlled the drug release but also directly destroyed the tumor, to enhance the therapeutic efficacy. As expected, the in vitro release studies showed that the drug release from CuDox-TSLs (Copper ion mediated Doxorubicin loading-Temperature Sensitive Liposomes) was both pH-dependent and temperature-dependent. Furthermore, MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assays showed that CuDox-TSLs combined with AuNRs exhibited a closer antiproliferative activity to free Dox in MCF-7 cells. The efficient intracellular Dox release from CuDox-TSLs toward the tumor cells further confirmed the anti-tumor effect. Moreover, the in vivo imaging and biodistribution studies revealed that CuDox-TSLs combined with AuNRs could actively target the tumor site. In addition, the therapeutic studies in MCF-7 nude mice exhibited CuDox-TSLs plus AuNRs in combination with NIR irradiation inhibited tumor growth to a great extent and possessed much lower side effects, which were further confirmed by systemic histological analyses. All detailed evidence suggested a considerable potential of CuDox-TSLs combined with AuNRs for treatment of metastatic cancer. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04353k

Proflavine sensitivity of RNA processing in isolated nuclei.

PubMed Central

Yannarell, A; Niemann, M; Schumm, D E; Webb, T E

1977-01-01

The intercalating agent proflavine inhibits the processing and subsequent release of preformed messenger RNA and ribosomal RNA from isolated liver nuclei to surrogate cytoplasm. The direct effect of proflavine on these processes, as monitored in a reconstituted cell-free system, supports the theory that base-paired segments (i.e. hairpin loops) in the precursor RNA's are involved as recognition sites in nuclear RNA processing. PMID:866181

Influence of riparian alteration on canopy coverage and macrophyte abundance in Southeastern USA blackwater streams

Treesearch

Dean E. Fletcher; S. David Wilkins; J.V. McArthur; Gary K. Meffe

2000-01-01

Two tributary streams (Fourmile branch and Pen branch) located on the US Department of Energy's Savannah river site in west-central South Carolina, USA received thermal discharges from nuclear production reactors for over 30 years. Effluent releases produced stream water temperatures of over 50°C and stream flows of ten times above their base level. Consequently,...

A magnetic, reversible pH-responsive nanogated ensemble based on Fe3O4 nanoparticles-capped mesoporous silica.

PubMed

Gan, Qi; Lu, Xunyu; Yuan, Yuan; Qian, Jiangchao; Zhou, Huanjun; Lu, Xun; Shi, Jianlin; Liu, Changsheng

2011-03-01

Stimuli-sensitive mesoporous silica nanoparticles (MSNs)-based hybrid "gate-like" ensembles capable of performing specific programmed release mode represent a new generation delivery system in recent years. In this paper, a magnetic and reversible pH-responsive, MSNs-based nanogated ensemble was fabricated by anchoring superparamagnetic Fe(3)O(4) nanoparticles on the pore outlet of MSNs via a reversible boronate esters linker. To achieve this, MSNs and Fe(3)O(4) nanoparticles were first synthesized and functionalized by polyalcohol derivative and boronic acid, respectively. The successful incorporation of Fe(3)O(4) nanoparticles onto the MSNs was confirmed by the results of XRD, TEM, XPS and N(2) adsorption-desorption method. The pH-driven "gate-like" effect was studied by in vitro release of an entrapped model dexamethasone from the pore voids into the bulk solution at different pH values. The results indicated that at pH 5-8, the pores of the MSNs were effectively capped with Fe(3)O(4) nanoparticles and the drug release was strongly inhibited. While at pH 2-4, the hydrolysis of the boroester bond took place and thus resulted in a rapid release of the entrapped drug. And by alternately changing the pH from 3 to 7, these Fe(3)O(4) cap gate could be switched "on" and "off" and thereby released the entrapped drug in a pulsinate manner (in small portions). Additionally, this nanogated release system exhibited good magnetic property, high cell biocompatibility and cellular uptake for MC3T3-E1 cells. The present data suggest that it is possible to obtain simple and very effective pH-driven pulsinate release using these Fe(3)O(4)-capped-MSNs, and this new platform represents a promising candidate in the formulation of in vivo targeted delivery of therapeutic agents to low pH tissues, such as tumors and inflammatory sites. Copyright © 2010 Elsevier Ltd. All rights reserved.

Endothelial stress induces the release of vitamin D-binding protein, a novel growth factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raymond, Marc-Andre; Desormeaux, Anik; Labelle, Andree

2005-12-23

Endothelial cells (EC) under stress release paracrine mediators that facilitate accumulation of vascular smooth muscle cells (VSCM) at sites of vascular injury. We found that medium conditioned by serum-starved EC increase proliferation and migration of VSCM in vitro. Fractionation of the conditioned medium followed by mass spectral analysis identified one bioactive component as vitamin D-binding protein (DBP). DBP induced both proliferation and migration of VSMC in vitro in association with increased phosphorylation of ERK 1/2. PD 98059, a biochemical inhibitor of ERK 1/2, abrogated these proliferative and migratory responses in VSMC. DBP is an important carrier for the vitamin-D sterols,more » 25-hydroxyvitamin-D, and 1{alpha},25-dihydroxyvitamin-D. Both sterols inhibited the activity of DBP on VSMC, suggesting that vitamin D binding sites are important for initiating the activities of DBP on VSMC. Release of DBP at sites of endothelial injury represents a novel pathway favoring accumulation of VSMC at sites of vascular injury.« less

Response of advance lodgepole pine regeneration to overstory removal in eastern Idaho

Treesearch

Tanya E. Lewis Murphy; David L. Adams; Dennis E. Ferguson

1999-01-01

Twenty-two stands of advance lodgepole pine released with overstory removal were sampled to determine height growth response. Tree and site characteristics correlated with release response were identified, and a mathematical model was developed to predict height growth in years 6 through 10 after release as a function of residual overstory basal area, height at release...

Long-term field evaluation of Mecinus janthinus releases against Dalmatian toadflax in Montana (USA)

Treesearch

Sharlene Sing; D. K. Weaver; R. M. Nowierski; G. P. Markin

2008-01-01

The toadflax stem mining weevil, Mecinus janthinus Germar, was first released in the United States in Montana, in 1996. This agent has now become established to varying degrees after subsequent releases made at sites throughout the state. Multiple releases of M. janthinus have presented researchers with a unique opportunity to evaluate the efficacy of this agent in...

The Sympathetic Release Test: A Test Used to Assess Thermoregulation and Autonomic Control of Blood Flow

ERIC Educational Resources Information Center

Tansey, E. A.; Roe, S. M.; Johnson, C. J.

2014-01-01

When a subject is heated, the stimulation of temperature-sensitive nerve endings in the skin, and the raising of the central body temperature, results in the reflex release of sympathetic vasoconstrictor tone in the skin of the extremities, causing a measurable temperature increase at the site of release. In the sympathetic release test, the…

In vitro evaluation of anticancer nanomedicines based on doxorubicin and amphiphilic Y-shaped copolymers

PubMed Central

Li, Di; Ding, Jian Xun; Tang, Zhao Hui; Sun, Hai; Zhuang, Xiu Li; Xu, Jing Zhe; Chen, Xue Si

2012-01-01

Four monomethoxy poly(ethylene glycol)-poly(L-lactide-co-glycolide)2 (mPEG-P( LA-co-GA)2) copolymers were synthesized by ring-opening polymerization of L-lactide and glycolide with double hydroxyl functionalized mPEG (mPEG-(OH)2) as macroinitiator and stannous octoate as catalyst. The copolymers self-assembled into nanoscale micellar/vesicular aggregations in phosphate buffer at pH 7.4. Doxorubicin (DOX), an anthracycline anticancer drug, was loaded into the micellar/vesicular nanoparticles, yielding micellar/vesicular nanomedicines. The in vitro release behaviors could be adjusted by content of hydrophobic polyester and pH of the release medium. In vitro cell experiments showed that the intracellular DOX release could be adjusted by content of P(LA-co-GA), and the nanomedicines displayed effective proliferation inhibition against Henrietta Lacks’s cells with different culture times. Hemolysis tests indicated that the copolymers were hemocompatible, and the presence of copolymers could reduce the hemolysis ratio of DOX significantly. These results suggested that the novel anticancer nanomedicines based on DOX and amphiphilic Y-shaped copolymers were attractive candidates as tumor tissular and intracellular targeting drug delivery systems in vivo, with enhanced stability during circulation and accelerated drug release at the target sites. PMID:22701317

Eleventh international CODATA conference, scientific and technical data in a new era, Karlsruhe, Federal Republic of Germany, 26--29 September 1988: Foreign trip report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tichler, J.L.

Information on release of radioactive materials in airborne and liquid effluents, solid waste shipments and selected operating information from commercial nuclear power plants in the United States is maintained in a computer data base at Brookhaven National Laboratory (BNL) for the United States Nuclear Regulatory Commission (USNRC). The information entered into the data base is obtained from semiannual reports submitted by the operators of the plants to the USNRC in compliance with the USNRC Regulatory Guide 1.21, ''Measuring, Evaluating, and Reporting Radioactivity in Solid Wastes and Releases of Radioactive Materials in Liquid and Gaseous Effluents from Light-Water-Cooled Nuclear Power Plants.''more » The data on releases in the calendar year 1986 include information from 69 plants representing 87 reactors and contain approximately 19,000 entries. Since all the information is contained in a computer data base management system, entry and rapidly respond to inquiries about the data set and to generate computer readable subsets of the data. Such a subset is used as input to the computer program which generates the annual report, ''Population Dose Commitments Due to Radioactive Releases from Nuclear Power Plant Sites,'' prepared by Pacific Northwest Laboratory for the USNRC. BNL began maintaining this data base for the USNRC with the 1978 information and has added information to the data base for each succeeding year. An annual report summarizing the information for each year, prepared by BNL, and published by the USNRC, is available to the general public. Prior to 1978, annual reports were prepared by the USNRC and are available for the years 1972--1977; however, the information for these years is not in a computer accessible data base.« less

Selective adsorption of oppositely charged PNIPAAM on halloysite surfaces: a route to thermo-responsive nanocarriers.

PubMed

Cavallaro, Giuseppe; Lazzara, Giuseppe; Lisuzzo, Lorenzo; Milioto, Stefana; Parisi, Filippo

2018-08-10

Halloysite nanotubes were functionalized with stimuli-responsive macromolecules to generate smart nanohybrids. Poly(N-isopropylacrylamide)-co-methacrylic acid (PNIPAAM-co-MA) was selectively adsorbed into halloysite lumen by exploiting electrostatic interactions. Amine-terminated PNIPAAM polymer was also investigated that selectively interacts with the outer surface of the nanotubes. The adsorption site has a profound effect on the thermodynamic behavior and therefore temperature responsive features of the hybrid material. The drug release kinetics was investigated by using diclofenac as a non-steroidal anti-inflammatory drug model. The release kinetics depends on the nanoarchitecture of the PNIPAAM/halloysite based material. In particular, diclofenac release was slowed down above the LCST for PNIPAAM-co-MA/halloysite. Opposite trends occurred for halloysite functionalized with PNIPAAM at the outer surface. This work represents a further step toward the opportunity to extend and control the delivery conditions of active species, which represent a key point in technological applications.

Environmental trends

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levin, M.; Smith, K.W.

1990-05-01

This article discusses Superfund's Amendments and Reauthorization Act of 1986; specifically, the provisions for release from liability for cleanup of contaminated property. These provisions are based on proof of innocence of prior knowledge before acquisition of the property. However, it appears that there are real problems in the determination of the level of inquiry necessary in good-faith site audits. Criminal penalties for knowing violations of permits or knowing releases of certain air emissions in the pending Clean Air Act may discourage sources from acquiring corrective knowledge through environmental audits. EPA's developing Enforcement for the 1990's project may seek to makemore » the absence of audit systems evidence of bad faith for general penalty purposes under the Agency's statutes.« less

Functions of tissue-resident eosinophils.

PubMed

Weller, Peter F; Spencer, Lisa A

2017-12-01

Eosinophils are a prominent cell type in particular host responses such as the response to helminth infection and allergic disease. Their effector functions have been attributed to their capacity to release cationic proteins stored in cytoplasmic granules by degranulation. However, eosinophils are now being recognized for more varied functions in previously underappreciated diverse tissue sites, based on the ability of eosinophils to release cytokines (often preformed) that mediate a broad range of activities into the local environment. In this Review, we consider evolving insights into the tissue distribution of eosinophils and their functional immunobiology, which enable eosinophils to secrete in a selective manner cytokines and other mediators that have diverse, 'non-effector' functions in health and disease.

76 FR 21299 - Emergency Planning and Notification; Emergency Planning and List of Extremely Hazardous...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-15

...EPA is proposing to revise the manner by which the regulated community would apply the threshold planning quantities (TPQs) for those extremely hazardous substances (EHSs) that are non-reactive solid chemicals in solution form. Specifically, facilities with a solid EHS in solution would be subject to the Emergency Planning requirements if the amount of the solid chemical on-site, when multiplied by 0.2, equaled or exceeded the lower published TPQ, based on data that shows less potential for the solid chemical in solution to remain airborne in the event of an accidental release. Previously, EPA assumed that 100% of the chemical could become airborne in the event of an accidental release.

The Lumenal Loop Met672–Pro707 of Copper-transporting ATPase ATP7A Binds Metals and Facilitates Copper Release from the Intramembrane Sites*

PubMed Central

Barry, Amanda N.; Otoikhian, Adenike; Bhatt, Sujata; Shinde, Ujwal; Tsivkovskii, Ruslan; Blackburn, Ninian J.; Lutsenko, Svetlana

2011-01-01

The copper-transporting ATPase ATP7A has an essential role in human physiology. ATP7A transfers the copper cofactor to metalloenzymes within the secretory pathway; inactivation of ATP7A results in an untreatable neurodegenerative disorder, Menkes disease. Presently, the mechanism of ATP7A-mediated copper release into the secretory pathway is not understood. We demonstrate that the characteristic His/Met-rich segment Met672–Pro707 (HM-loop) that connects the first two transmembrane segments of ATP7A is important for copper release. Mutations within this loop do not prevent the ability of ATP7A to form a phosphorylated intermediate during ATP hydrolysis but inhibit subsequent dephosphorylation, a step associated with copper release. The HM-loop inserted into a scaffold protein forms two structurally distinct binding sites and coordinates copper in a mixed His-Met environment with an ∼2:1 stoichiometry. Binding of either copper or silver, a Cu(I) analog, induces structural changes in the loop. Mutations of 4 Met residues to Ile or two His-His pairs to Ala-Gly decrease affinity for copper. Altogether, the data suggest a two-step process, where copper released from the transport sites binds to the first His(Met)2 site, triggering a structural change and binding to a second 2-coordinate His-His or His-Met site. We also show that copper binding within the HM-loop stabilizes Cu(I) and protects it from oxidation, which may further aid the transfer of copper from ATP7A to acceptor proteins. The mechanism of copper entry into the secretory pathway is discussed. PMID:21646353

Site-wide seismic risk model for Savannah River Site nuclear facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eide, S.A.; Shay, R.S.; Durant, W.S.

1993-09-01

The 200,000 acre Savannah River Site (SRS) has nearly 30 nuclear facilities spread throughout the site. The safety of each facility has been established in facility-specific safety analysis reports (SARs). Each SAR contains an analysis of risk from seismic events to both on-site workers and the off-site population. Both radiological and chemical releases are considered, and air and water pathways are modeled. Risks to the general public are generally characterized by evaluating exposure to the maximally exposed individual located at the SRS boundary and to the off-site population located within 50 miles. Although the SARs are appropriate methods for studyingmore » individual facility risks, there is a class of accident initiators that can simultaneously affect several of all of the facilities, Examples include seismic events, strong winds or tornados, floods, and loss of off-site electrical power. Overall risk to the off-site population from such initiators is not covered by the individual SARs. In such cases multiple facility radionuclide or chemical releases could occur, and off-site exposure would be greater than that indicated in a single facility SAR. As a step towards an overall site-wide risk model that adequately addresses multiple facility releases, a site-wide seismic model for determining off-site risk has been developed for nuclear facilities at the SRS. Risk from seismic events up to the design basis earthquake (DBE) of 0.2 g (frequency of 2.0E-4/yr) is covered by the model. Present plans include expanding the scope of the model to include other types of initiators that can simultaneously affect multiple facilities.« less

Sulfation of K-based Lean NOx Trap while Cycling Between Lean and Rich Conditions: I. Microreactor Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Toops, Todd J; Pihl, Josh A

2008-01-01

Exposure of Pt/K/Al{sub 2}O{sub 3} to 15 ppm SO{sub 2} reduces the NOx activity at 200, 300, and 400 C at significantly different rates--1.5, 8.5, and 18.0 {micro}mol NOx/(h g{sub cat}), respectively. During the initial sulfation, NOx conversion is directly linked to lean phase storage capacity, and sulfation does not impact the reduction kinetics since the amount of unconverted NOx was constant or decreased with increasing sulfation time. A portion of sulfur stored at 200 C desorbs upon mild heating to 400 C while cycling between lean and rich conditions. This apparently is a result of sulfur being released frommore » Al{sub 2}O{sub 3}; however, performance is not significantly recovered as much of the sulfur is re-adsorbed on the K-phase. This is apparent from analysis of the NOx storage and release profiles. Additional analysis of these profiles suggests that SO{sub 2} initially adsorbs near Pt before interacting with other sites further away from Pt at 300 C. At 400 C, it appears that SO{sub 2} either preferentially adsorbs near Pt and then quickly diffuses along the surface to other less proximal sites, or it directly adsorbs on sites further away from Pt. De-sulfurization up to 800 C using a temperature programmed reduction (TPR) procedure and rich conditions with both CO{sub 2} and H{sub 2}O restored 73=94% of the LNT performance at 300 and 400 C. However, the recovered performance measured at 200 C was only 34-49% of the original NOx reduction activity. H{sub 2}S and SO{sub 2} were the primary de-sulfurization products with H{sub 2}S having a maximum release between 690 and 755 C, while SO{sub 2} had a peak release between 770 and 785 C. The sulfation temperature does not have a significant impact on the recovered performance, the de-sulfurization products or the sulfur release temperature.« less

Release and establishment of Megamelus scutellaris (Hemiptera: Delphacidae) in Florida

USDA-ARS?s Scientific Manuscript database

Megamelus scutellaris (Berg) (Hemiptera: Delphacidae) was recently developed as a classical biological control agent for waterhyacinth, Eichhornia crassipes Mart. Solms, and released in Florida. Releases were conducted at 10 sites around the state every 4-6 weeks until late fall then halted until t...

Indirect effects and traditional trophic cascades: a test involving wolves, coyotes, and pronghorn.

PubMed

Berger, Kim Murray; Gese, Eric M; Berger, Joel

2008-03-01

The traditional trophic cascades model is based on consumer resource interactions at each link in a food chain. However, trophic-level interactions, such as mesocarnivore release resulting from intraguild predation, may also be important mediators of cascades. From September 2001 to August 2004, we used spatial and seasonal heterogeneity in wolf distribution and abundance in the southern Greater Yellowstone Ecosystem to evaluate whether mesopredator release of coyotes (Canis latrans), resulting from the extirpation of wolves (Canis lupus), accounts for high rates of coyote predation on pronghorn (Antilocapra americana) fawns observed in some areas. Results of this ecological perturbation in wolf densities, coyote densities, and pronghorn neonatal survival at wolf-free and wolf-abundant sites support the existence of a species-level trophic cascade. That wolves precipitated a trophic cascade was evidenced by fawn survival rates that were four-fold higher at sites used by wolves. A negative correlation between coyote and wolf densities supports the hypothesis that interspecific interactions between the two species facilitated the difference in fawn survival. Whereas densities of resident coyotes were similar between wolf-free and wolf-abundant sites, the abundance of transient coyotes was significantly lower in areas used by wolves. Thus, differential effects of wolves on solitary coyotes may be an important mechanism by which wolves limit coyote densities. Our results support the hypothesis that mesopredator release of coyotes contributes to high rates of coyote predation on pronghorn fawns, and demonstrate the importance of alternative food web pathways in structuring the dynamics of terrestrial systems.

Recent advances in oral pulsatile drug delivery.

PubMed

Kalantzi, Lida E; Karavas, Evangelos; Koutris, Efthimios X; Bikiaris, Dimitrios N

2009-01-01

Pulsatile drug delivery aims to release drugs on a programmed pattern i.e.: at appropriate time and/or at appropriate site of action. Currently, it is gaining increasing attention as it offers a more sophisticated approach to the traditional sustained drug delivery i.e: a constant amount of drug released per unit time or constant blood levels. Technically, pulsatile drug delivery systems administered via the oral route could be divided into two distinct types, the time controlled delivery systems and the site-specific delivery systems. The simplest pulsatile formulation is a two layer press coated tablet consisted of polymers with different dissolution rates. Homogenicity of the coated barrier is mandatory in order to assure the predictability of the lag time. The disadvantage of such formulation is that the rupture time cannot be always adequately manipulated as it is strongly correlated with the physicochemical properties of the polymer. Gastric retentive systems, systems where the drug is released following a programmed lag phase, chronopharmaceutical drug delivery systems matching human circadian rhythms, multiunit or multilayer systems with various combinations of immediate and sustained-release preparation, are all classified under pulsatile drug delivery systems. On the other hand, site-controlled release is usually controlled by factors such as the pH of the target site, the enzymes present in the intestinal tract and the transit time/pressure of various parts of the intestine. In this review, recent patents on pulsatile drug delivery of oral dosage forms are summarized and discussed.

Vapor intrusion risk of lead scavengers 1,2-dibromoethane (EDB) and 1,2-dichloroethane (DCA).

PubMed

Ma, Jie; Li, Haiyan; Spiese, Richard; Wilson, John; Yan, Guangxu; Guo, Shaohui

2016-06-01

Vapor intrusion of synthetic fuel additives represented a critical yet still neglected problem at sites impacted by petroleum fuel releases. This study used an advanced numerical model to simulate the vapor intrusion risk of lead scavengers 1,2-dibromoethane (ethylene dibromide, EDB) and 1,2-dichloroethane (DCA) under different site conditions. We found that simulated EDB and DCA indoor air concentrations can exceed USEPA screening level (4.7 × 10(-3) μg/m(3) for EDB and 1.1 × 10(-1) μg/m(3) for DCA) if the source concentration is high enough (is still within the concentration range found at leaking UST site). To evaluate the chance that vapor intrusion of EDB might exceed the USEPA screening levels for indoor air, the simulation results were compared to the distribution of EDB at leaking UST sites in the US. If there is no degradation of EDB or only abiotic degradation of EDB, from 15% to 37% of leaking UST sites might exceed the USEPA screening level. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the screening criteria for petroleum hydrocarbon may not provide sufficient protectiveness for fuel releases containing EDB and DCA. Based on a thorough literature review, we also compiled previous published data on the EDB and DCA groundwater source concentrations and their degradation rates. These data are valuable in evaluating EDB and DCA vapor intrusion risk. In addition, a set of refined attenuation factors based on site-specific information (e.g., soil types, source depths, and degradation rates) were provided for establishing site-specific screening criteria for EDB and DCA. Overall, this study points out that lead scavengers EDB and DCA may cause vapor intrusion problems. As more field data of EDB and DCA become available, we recommend that USEPA consider including these data in the existing PVI database and possibly revising the PVI Guidance as necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intracellular delivery and antitumor effects of a redox-responsive polymeric paclitaxel conjugate based on hyaluronic acid.

PubMed

Yin, Shaoping; Huai, Jue; Chen, Xi; Yang, Yong; Zhang, Xinxin; Gan, Yong; Wang, Guangji; Gu, Xiaochen; Li, Juan

2015-10-01

Polymer-drug conjugates have demonstrated application potentials in optimizing chemotherapeutics. In this study a new bioconjugate, HA-ss-PTX, was designed and synthesized with cooperative dual characteristics of active tumor targeting and selective intracellular drug release. Paclitaxel (PTX) was covalently attached to hyaluronic acid (HA) with various sizes (MW 9.5, 35, 770 kDa); a cross-linker containing disulfide bond was also used to shield drug leakage in blood circulation and to achieve rapid drug release in tumor cells in response to glutathione. Incorporation of HA to the conjugate enhanced the capabilities of drug loading, intracellular endocytosis and tumor targeting of micelles in comparison to mPEG. HA molecular weight showed significant effect on properties and antitumor efficacy of the synthesized conjugates. Intracellular uptake of HA-ss-PTX toward MCF-7 cells was mediated by CD44-caveolae-mediated endocytosis. Compared to Taxol and mPEG-ss-PTX, HA9.5-ss-PTX demonstrated improved tumor growth inhibition in vivo with a TIR of 83.27 ± 5.20%. It was concluded that HA9.5-ss-PTX achieved rapid intracellular release of PTX and enhanced its therapeutic efficacy, thus providing a platform for specific drug targeting and controlled intracellular release in chemotherapeutics. Polymer-drug conjugates, promising nanomedicines, still face some technical challenges including a lack of specific targeting and rapid intracellular drug release at the target site. In this manuscript we designed and constructed a novel bioconjugate HA-ss-PTX, which possessed coordinated dual characteristics of active tumor targeting and selective intracellular drug release. Redox-responsive disulfide bond was introduced to the conjugate to shield drug leakage in blood circulation and to achieve rapid drug release at tumor site in response to reductant like glutathione. Paclitaxel was selected as a model drug to be covalently attached to hyaluronic acid (HA) with various sizes to elucidate the structure-activity relationship and to address whether HA could substitute PEG as a carrier for polymeric conjugates. Based on a series of in vitro and in vivo experiments, HA-ss-PTX performed well in drug loading, cellular internalization, tumor targeting by entering tumor cells via CD44-caveolae-mediated endocytosis and rapidly release drug at target in the presence of GSH. One of the key issues in clinical oncology is to enhance drug delivery efficacy while minimizing side effects. The study indicated that this new polymeric conjugate system would be useful in delivering anticancer agents to improve therapeutic efficacy and to minimize adverse effects, thus providing a platform for specific drug targeting and controlled intracellular release in chemotherapeutics. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Plutonium Particle Migration in the Shallow Vadose Zone: The Nevada Test Site as an Analog Site

NASA Astrophysics Data System (ADS)

Hunt, J. R.; Smith, D. K.

2004-12-01

The upper meter of the vadose zone in desert environments is the horizon where wastes have been released and human exposure is determined through dermal, inhalation, and food uptake pathways. This region is also characterized by numerous coupled processes that determine contaminant transport, including precipitation infiltration, evapotranspiration, daily and annual temperature cycling, dust resuspension, animal burrowing, and geochemical weathering reactions. While there is considerable interest in colloidal transport of minerals, pathogenic organisms, and contaminants in the vadose zone, there are limited field sites where the actual occurrence of contaminant migration can be quantified over the appropriate spatial and temporal scales of interest. At the US Department of Energy Nevada Test Site, there have been numerous releases of radionuclides since the 1950's that have become field-scale tracer tests. One series of tests was the four safety shots conducted in an alluvial valley of Area 11 in the 1950's. These experiments tested the ability of nuclear materials to survive chemical explosions without initiating fission reactions. Four above-ground tests were conducted and they released plutonium and uranium on the desert valley floor with only one of the tests undergoing some fission. Shortly after the tests, the sites were surveyed for radionuclide distribution on the land surface using aerial surveys and with depth. Additional studies were conducted in the 1970's to better understand the fate of plutonium in the desert that included studies of depth distribution and dust resuspension. More recently, plutonium particle distribution in the soil profile was detected using autoradiography. The results to date demonstrate the vertical migration of plutonium particles to depths in excess of 30 cm in this arid vadose zone. While plutonium migration at the Nevada Test Site has been and continues to be a concern, these field experiments have become analog sites for the release of radiological materials potentially important to consequence management investigations. In particular, these 50-year old experiments with long and detailed site investigations under relative undisturbed conditions offer insights into transport pathways that must be represented in simulation models that evaluate responses to radiological dispersal devices (RDDs). A compilation of the available site characterization data suggests additional experimental and modeling programs that can ultimately quantify the fate of contaminant particles released at the soil surface.

The Binomial Model in Fluctuation Analysis of Quantal Neurotransmitter Release

PubMed Central

Quastel, D. M. J.

1997-01-01

The mathematics of the binomial model for quantal neurotransmitter release is considered in general terms, to explore what information might be extractable from statistical aspects of data. For an array of N statistically independent release sites, each with a release probability p, the compound binomial always pertains, with = N

, p′ ≡ 1 - var(m)/ =

(1 + cvp2) and n′ ≡ /p′ = N/(1 + cvp2), where m is the output/stimulus and cvp2 is var(p)/

2. Unless n′ is invariant with ambient conditions or stimulation paradigms, the simple binomial (cvp = 0) is untenable and n′ is neither N nor the number of “active” sites or sites with a quantum available. At each site p = popA, where po is the output probability if a site is “eligible” or “filled” despite previous quantal discharge, and pA (eligibility probability) depends at least on the replenishment rate, po, and interstimulus time. Assuming stochastic replenishment, a simple algorithm allows calculation of the full statistical composition of outputs for any hypothetical combinations of po's and refill rates, for any stimulation paradigm and spontaneous release. A rise in n′ (reduced cvp) tends to occur whenever po varies widely between sites, with a raised stimulation frequency or factors tending to increase po's. Unlike and var(m) at equilibrium, output changes early in trains of stimuli, and covariances, potentially provide information about whether changes in reflect change in or in . Formulae are derived for variance and third moments of postsynaptic responses, which depend on the quantal mix in the signals. A new, easily computed function, the area product, gives noise-unbiased variance of a series of synaptic signals and its peristimulus time distribution, which is modified by the unit channel composition of quantal responses and if the signals reflect mixed responses from synapses with different quantal time course. PMID:9017200

Factors affecting settling, survival, and viability of black bears reintroduced to Felsenthal National Wildlife Refuge, Arkansas

USGS Publications Warehouse

Wear, B.J.; Eastridge, R.; Clark, J.D.

2005-01-01

We used radiotelemetry and population modeling techniques to examine factors related to population establishment of black bears (Ursus americanus) reintroduced to Felsenthal National Wildlife Refuge (NWR), Arkansas. Our objectives were to determine whether settling (i.e., establishment of a home range at or near the release site), survival, recruitment, and population viability were related to age class of reintroduced bears, presence of cubs, time since release, or number of translocated animals. We removed 23 adult female black bears with 56 cubs from their winter dens at White River NWR and transported them 160 km to man-made den structures at Felsenthal NWR during spring 2000–2002. Total movement and average circuity of adult females decreased from 1 month, 6 months, and 1 year post-emergence (F2,14 =19.7, P < 0.001 and F2,14 =5.76, P=0.015, respectively). Mean first-year post-release survival of adult female bears was 0.624 (SE = 0.110, SEinterannual = 0.144), and the survival rate of their cubs was 0.750 (SE = 0.088, SEinterannual = 0.109). The homing rate (i.e., the proportion of bears that returned to White River NWR) was 13%. Annual survival for female bears that remained at the release site and survived >1-year post-release increased to 0.909 (SE = 0.097, SEinterannual=0.067; Z=3.5, P < 0.001). Based on stochastic population growth simulations, the average annual growth rate (λ) was 1.093 (SD = 0.053) and the probability of extinction with no additional stockings ranged from 0.56-1.30%. The bear population at Felsenthal NWR is at or above the number after which extinction risk declines dramatically, although additional releases of bears could significantly decrease time to population reestablishment. Poaching accounted for at least 3 of the 8 adult mortalities that we documented; illegal kills could be a significant impediment to population re-establishment at Felsenthal NWR should poaching rates escalate.

Challenges associated with the behaviour of radioactive particles in the environment.

PubMed

Salbu, Brit; Kashparov, Valery; Lind, Ole Christian; Garcia-Tenorio, Rafael; Johansen, Mathew P; Child, David P; Roos, Per; Sancho, Carlos

2018-06-01

A series of different nuclear sources associated with the nuclear weapon and fuel cycles have contributed to the release of radioactive particles to the environment. Following nuclear weapon tests, safety tests, conventional destruction of weapons, reactor explosions and fires, a major fraction of released refractory radionuclides such as uranium (U) and plutonium (Pu) were present as entities ranging from sub microns to fragments. Furthermore, radioactive particles and colloids have been released from reprocessing facilities and civil reactors, from radioactive waste dumped at sea, and from NORM sites. Thus, whenever refractory radionuclides are released to the environment following nuclear events, radioactive particles should be expected. Results from many years of research have shown that particle characteristics such as elemental composition depend on the source, while characteristics such as particle size distribution, structure, and oxidation state influencing ecosystem transfer depend also on the release scenarios. When radioactive particles are deposited in the environment, weathering processes occur and associated radionuclides are subsequently mobilized, changing the apparent K d . Thus, particles retained in soils or sediments are unevenly distributed, and dissolution of radionuclides from particles may be partial. For areas affected by particle contamination, the inventories can therefore be underestimated, and impact and risk assessments may suffer from unacceptable large uncertainties if radioactive particles are ignored. To integrate radioactive particles into environmental impact assessments, key challenges include the linking of particle characteristics to specific sources, to ecosystem transfer, and to uptake and retention in biological systems. To elucidate these issues, the EC-funded COMET and RATE projects and the IAEA Coordinated Research Program on particles have revisited selected contaminated sites and archive samples. This COMET position paper summarizes new knowledge on key sources that have contributed to particle releases, including particle characteristics based on advanced techniques, with emphasis on particle weathering processes as well as on heterogeneities in biological samples to evaluate potential uptake and retention of radioactive particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of beta-cyclodextrin and chitosan in the formulation of a colon-specific drug delivery system.

PubMed

Rehman, K; Amin, M C I M; Muda, S

2013-12-01

The increase in diseases of the colon underscores the need to develop cost-effective site-directed therapies. We formulated a polysaccharide-based matrix system that could release ibuprofen under conditions simulating those in the colon by employing a wet granulation method. Tablets were prepared in a series of formulations containing a polysaccharide (beta-cyclodextrin and chitosan) matrix system along with ethylcellulose. We characterized physicochemical properties and performed an in vitro drug release assay in the absence and presence of digestive enzymes to assess the ability of the polysaccharides to function as a protective barrier against the upper gastrointestinal environment. Fourier transform infrared spectroscopy studies revealed no chemical interaction between ibuprofen and polysaccharides; however, spectrum analysis suggested the formation of an inclusion complex of beta-cyclodextrin with ibuprofen. The formulations contained 50% ethylcellulose and 50% beta-cyclodextrins (1:1) were proven to be the better formulation that slowly released the drug until 24 h (101.04 ± 0.65% maximum drug release in which 83.08 ± 0.89% drug was released in colonic medium) showed better drug release profiles than the formulations containing chitosan. We conclude that a beta-cyclodextrin drug carrier system may represent an effective approach for treatment of diseases of the colon. © Georg Thieme Verlag KG Stuttgart · New York.

KSC01pp0681

NASA Image and Video Library

2001-04-03

KENNEDY SPACE CENTER, FLA. -- A large adult manatee requires many helpers to lift it out of the van that brought it from Sea World for release into the Banana River. The site is on the north side of the NASA Causeway, near Kennedy Space Center. A calf was also released at the site. Manatees are frequently seen in the waters around Kennedy Space Center, which is surrounded by the Merritt Island National Wildlife Refuge

Paired-pulse facilitation and depression at unitary synapses in rat hippocampus: quantal fluctuation affects subsequent release.

PubMed Central

Debanne, D; Guérineau, N C; Gähwiler, B H; Thompson, S M

1996-01-01

1. Excitatory synaptic transmission between pairs of monosynaptically coupled pyramidal cells was examined in rat hippocampal slice cultures. Action potentials were elicited in single CA3 pyramidal cells impaled with microelectrodes and unitary excitatory postsynaptic currents (EPSCs) were recorded in whole-cell voltage-clamped CA1 or CA3 cells. 2. The amplitude of successive unitary EPSCs in response to single action potentials varied. The amplitude of EPSCs was altered by adenosine or changes in the [Mg2+]/[CA2+] ratio. We conclude that single action potentials triggered the release of multiple quanta of glutamate. 3. When two action potentials were elicited in the presynaptic cell, the amplitude of the second EPSC was inversely related to the amplitude of the first. Paired-pulse facilitation (PPF) was observed when the first EPSC was small, i.e. the second EPSC was larger than the first, whereas paired-pulse depression (PPD) was observed when the first EPSC was large. 4. The number of trials displaying PPD was greater when release probability was increased, and smaller when release probability was decreased. 5. PPD was not postsynaptically mediated because it was unaffected by decreasing ionic flux with 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or receptor desensitization with aniracetam. 6. PPF was maximal at an interstimulus interval of 70 ms and recovered within 500 ms. Recovery from PPD occurred within 5 s. 7. We propose that multiple release sites are formed by the axon of a CA3 pyramidal cell and a single postsynaptic CA1 or CA3 cell. PPF is observed if the first action potential fails to release transmitter at most release sites. PPD is observed if the first action potential successfully triggers release at most release sites. 8. Our observations of PPF are consistent with the residual calcium hypothesis. We conclude that PPD results from a decrease in quantal content, perhaps due to short-term depletion of readily releasable vesicles. PMID:9011608

Repair of radiation-induced heat-labile sites is independent of DNA-PKcs, XRCC1 or PARP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stenerlöw, Bo; Karlsson, Karin H.; Radulescu, Irina

2008-04-29

Ionizing radiation induces a variety of different DNA lesions: in addition to the most critical DNA damage, the DSB, numerous base alterations, SSBs and other modifications of the DNA double-helix are formed. When several non-DSB lesions are clustered within a short distance along DNA, or close to a DSB, they may interfere with the repair of DSBs and affect the measurement of DSB induction and repair. We have previously shown that a substantial fraction of DSBs measured by pulsed-field gel electrophoresis (PFGE) are in fact due to heat-labile sites (HLS) within clustered lesions, thus reflecting an artifact of preparation ofmore » genomic DNA at elevated temperature. To further characterize the influence of HLS on DSB induction and repair, four human cell lines (GM5758, GM7166, M059K, U-1810) with apparently normal DSB rejoining were tested for bi-phasic rejoining after gamma irradiation. When heat-released DSBs were excluded from the measurements the fraction of fast rejoining decreased to less than 50% of the total. However, neither the half-times of the fast (t{sub 1/2} = 7-8 min) or slow (t{sub 1/2} = 2.5 h) DSB rejoining were changed significantly. At t=0 the heat-released DSBs accounted for almost 40% of the DSBs, corresponding to 10 extra DSB/cell/Gy in the initial DSB yield. These heat-released DSBs were repaired within 60-90 min in all tested cells, including M059K cells treated with wortmannin or DNA-PKcs defect M059J cells. Furthermore, cells lacking XRCC1 or Poly(ADP-ribose) polymerase-1 (PARP-1) rejoined both total DSBs and heat-released DSBs similar to normal cells. In summary, the presence of heat-labile sites have a substantial impact on DSB induction yields and DSB rejoining rates measured by pulsed-field gel electrophoresis, and HLS repair is independent of DNA-PKcs, XRCC1 and PARP.« less

Methane ebullition fluxes from northern peatlands: initial observations from four sites of contrasting vegetation type in Caribou Bog, ME

NASA Astrophysics Data System (ADS)

Slater, L. D.; Comas, X.; Mumford, K. G.; Reeve, A. S.; Varner, R. K.; Chen, X.; Wright, W.; Wright, J.; Molnar, I. L.; Krol, M.

2017-12-01

The contribution of peatlands to the atmospheric CH4 burden remains unclear in large part due to incomplete understanding of the ebullition pathway. Oxidation of dissolved methane reduces the release of methane by diffusion, but the transit time of bubbles released via ebullition is too short for extensive oxidation to occur, i.e. ebullition releases increase the greenhouse gas potential of peatlands. We are working to couple innovative strategies for ebullition monitoring with a physical model describing gas transport in terms of the mechanical properties of the peat. This integration of measurement and modeling will permit a fundamental step forward towards a more quantitative understanding of CH4 ebullition from peatlands. Sampling and sensor installation have been performed in Caribou Bog, a multi-unit peatland located in Maine (USA) where an extensive database accounting for a decade of research is already available from previous work examining methane dynamics. Multi-depth gas trap and moisture probe arrays have been installed at four sites selected based on contrasting vegetation type and peat basin depth determined from extensive ground penetrating radar surveys. Hydraulic head measurements have also been acquired on multi-level piezometers designed to capture transient signals associated with gas transport. Cores and initial field observations acquired in summer 2017 confirm that the physical properties of the peat vary markedly between the sites and influence gas storage and release. An existing ebullition model describing gas bubble expansion is being coupled with an invasion percolation approach to describe the transport of CH4 between multiple peat layers by both diffusion in the pore water and ebullition between layers. Although the proposed model does not explicitly incorporate the geomechanical properties of peat, model predictions for maximum gas contents are being compared with key measurable geomechanical properties (including measured capillary drainage curves for peat) that may control ebullition.

Perspective on the combined use of an independent transgenic sexing and a multifactorial reproductive sterility system to avoid resistance development against transgenic Sterile Insect Technique approaches

PubMed Central

2014-01-01

Background The Sterile Insect Technique (SIT) is an accepted species-specific genetic control approach that acts as an insect birth control measure, which can be improved by biotechnological engineering to facilitate its use and widen its applicability. First transgenic insects carrying a single killing system have already been released in small scale trials. However, to evade resistance development to such transgenic approaches, completely independent ways of transgenic killing should be established and combined. Perspective Most established transgenic sexing and reproductive sterility systems are based on the binary tTA expression system that can be suppressed by adding tetracycline to the food. However, to create 'redundant killing' an additional independent conditional expression system is required. Here we present a perspective on the use of a second food-controllable binary expression system - the inducible Q system - that could be used in combination with site-specific recombinases to generate independent transgenic killing systems. We propose the combination of an already established transgenic embryonic sexing system to meet the SIT requirement of male-only releases based on the repressible tTA system together with a redundant male-specific reproductive sterility system, which is activated by Q-system controlled site-specific recombination and is based on a spermatogenesis-specifically expressed endonuclease acting on several species-specific target sites leading to chromosome shredding. Conclusion A combination of a completely independent transgenic sexing and a redundant reproductive male sterility system, which do not share any active components and mediate the induced lethality by completely independent processes, would meet the 'redundant killing' criteria for suppression of resistance development and could therefore be employed in large scale long-term suppression programs using biotechnologically enhanced SIT. PMID:25471733

Osmotic Drug Delivery System as a Part of Modified Release Dosage Form

PubMed Central

Keraliya, Rajesh A.; Patel, Chirag; Patel, Pranav; Keraliya, Vipul; Soni, Tejal G.; Patel, Rajnikant C.; Patel, M. M.

2012-01-01

Conventional drug delivery systems are known to provide an immediate release of drug, in which one can not control the release of the drug and can not maintain effective concentration at the target site for longer time. Controlled drug delivery systems offer spatial control over the drug release. Osmotic pumps are most promising systems for controlled drug delivery. These systems are used for both oral administration and implantation. Osmotic pumps consist of an inner core containing drug and osmogens, coated with a semipermeable membrane. As the core absorbs water, it expands in volume, which pushes the drug solution out through the delivery ports. Osmotic pumps release drug at a rate that is independent of the pH and hydrodynamics of the dissolution medium. The historical development of osmotic systems includes development of the Rose-Nelson pump, the Higuchi-Leeper pumps, the Alzet and Osmet systems, the elementary osmotic pump, and the push-pull system. Recent advances include development of the controlled porosity osmotic pump, and systems based on asymmetric membranes. This paper highlights the principle of osmosis, materials used for fabrication of pumps, types of pumps, advantages, disadvantages, and marketed products of this system. PMID:22852100

Tailoring biocontrol to maximize top-down effects: on the importance of underlying site fertility.

PubMed

Hovick, Stephen M; Carson, Walter P

2015-01-01

The degree to which biocontrol agents impact invasive plants varies widely across landscapes, often for unknown reasons. Understanding this variability can help optimize invasive species management while also informing our understanding of trophic linkages. To address these issues, we tested three hypotheses with contrasting predictions regarding the likelihood of biocontrol success. (1) The biocontrol effort hypothesis: invasive populations are regulated primarily by top-down effects, predicting that increased biocontrol efforts alone (e.g., more individuals of a given biocontrol agent or more time since agent release) will enhance biocontrol success. (2) The relative fertility hypothesis: invasive populations are regulated primarily by bottom-up effects, predicting that nutrient enrichment will increase dominance by invasives and thus reduce biocontrol success, regardless of biocontrol efforts. (3) The fertility-dependent biocontrol effort hypothesis: top-down effects will only regulate invasive populations if bottom-up effects are weak. It predicts that greater biocontrol efforts will increase biocontrol success, but only in low-nutrient sites. To test these hypotheses, we surveyed 46 sites across three states with prior releases of Galerucella beetles, the most common biocontrol agents used against invasive purple loosestrife (Lythrum salicaria). We found strong support for the fertility-dependent biocontrol effort hypothesis, as biocontrol success occurred most often with greater biocontrol efforts, but only in low-fertility sites. This result held for early stage metrics of biocontrol success (higher Galerucella abundance) and ultimate biocontrol outcomes (decreased loosestrife plant size and abundance). Presence of the invasive grass Phalaris arundinacea was also inversely related to loosestrife abundance, suggesting that biocontrol-based reductions in loosestrife made secondary invasion by P. arundinacea more likely. Our data suggest that low-nutrient sites be prioritized for loosestrife biocontrol and that future monitoring account for variation in site fertility or work to mitigate it. We introduce a new framework that integrates our findings with conflicting patterns previously reported from other biocontrol systems, proposing a unimodal relationship whereby nutrient availability enhances biocontrol success in low-nutrient sites but hampers it in high-nutrient sites. Our results represent one of the first examples of biocontrol success depending on site fertility, which has the potential to inform biocontrol-based management decisions across entire regions and among contrasting systems.

Superfund Site Assessment Process

EPA Pesticide Factsheets

Learn about the site assessment process used by the federal Superfund program to evaluate releases of hazardous substances that may pose a threat to human health or the environment and select an appropriate program for sites needing cleanup.

Interannual and Seasonal Patterns of Carbon Dioxide, Water, and Energy Fluxes From Ecotonal and Thermokarst-Impacted Ecosystems on Carbon-Rich Permafrost Soils in Northeastern Siberia

NASA Astrophysics Data System (ADS)

Euskirchen, Eugénie S.; Edgar, Colin W.; Syndonia Bret-Harte, M.; Kade, Anja; Zimov, Nikita; Zimov, Sergey

2017-10-01

Eastern Siberia Russia is currently experiencing a distinct and unprecedented rate of warming. This change is particularly important given the large amounts of carbon stored in the yedoma permafrost soils that become vulnerable to thaw and release under warming. Data from this region pertaining to year-round carbon, water, and energy fluxes are scarce, particularly in sensitive ecotonal ecosystems near latitudinal treeline, as well as those already impacted by permafrost thaw. Here we investigated the interannual and seasonal carbon dioxide, water, and energy dynamics at an ecotonal forested site and a disturbed thermokarst-impacted site. The ecotonal site was approximately neutral in terms of CO2 uptake/release, while the disturbed site was either a source or neutral. Our data suggest that high rates of plant productivity during the growing season at the disturbed site may, in part, counterbalance higher rates of respiration during the cold season compared to the ecotonal site. We also found that the ecotonal site was sensitive to the timing of the freezeup of the soil active layer in fall, releasing more CO2 when freezeup occurred later. Both sites showed a negative water balance, although the ecotonal site appeared more sensitive to dry conditions. Water use efficiency at the ecotonal site was lower during warmer summers. Overall, these Siberian measurements indicate ecosystem sensitivity to warmer conditions during the fall and to drier conditions during the growing season and provide a better understanding of ecosystem response to climate in a part of the circumpolar Arctic where current knowledge is weakest.

Environmental Fate and Transport of Poly- and Perfluoroalkyl Substances at Aqueous Film-Forming Foam Impacted Sites

NASA Astrophysics Data System (ADS)

Higgins, C.

2017-12-01

Poly and perfluoroalkyl substances (PFASs) are constituents in aqueous film-forming foam (AFFF) used to extinguish fuel fires. Substantially elevated PFAS groundwater concentrations have been observed at firefighter protection training areas, where co-contaminants such as chlorinated solvents and fuel hydrocarbons are also commonly present. Research into the fate and transport potential of PFASs at AFFF-impacted sites will be presented, with a particular focus on how co-contaminants and co-contaminant remediation technologies may alter the composition and transport behavior of PFASs at these sites. A detailed analysis of data collected from a U.S. Air Force site (Ellsworth Air Force Base, South Dakota) indicates that that conversion of polyfluoroalkyl chemicals to perfluoroalkyl acids (PFAAs) in situ due to natural and enhanced remediation of petroleum hydrocarbons. In addition, bench-scale studies examining the effects of various chemical oxidants, typically employed via in situ chemical oxidation (ISCO), indicates that oxidation-based remediation technologies have the potential to alter the release and composition of PFASs in AFFF-impacted source zones. Future challenges in addressing PFAS contamination will be discussed, particularly with respect to closing the mass balance on PFAAs and their precursors at AFFF-impacted sites.

Indocyanine Green-Loaded Liposomes for Light-Triggered Drug Release.

PubMed

Lajunen, Tatu; Kontturi, Leena-Stiina; Viitala, Lauri; Manna, Moutusi; Cramariuc, Oana; Róg, Tomasz; Bunker, Alex; Laaksonen, Timo; Viitala, Tapani; Murtomäki, Lasse; Urtti, Arto

2016-06-06

Light-triggered drug delivery systems enable site-specific and time-controlled drug release. In previous work, we have achieved this with liposomes containing gold nanoparticles in the aqueous core. Gold nanoparticles absorb near-infrared light and release the energy as heat that increases the permeability of the liposomal bilayer, thus releasing the contents of the liposome. In this work, we replaced the gold nanoparticles with the clinically approved imaging agent indocyanine green (ICG). The ICG liposomes were stable at storage conditions (4-22 °C) and at body temperature, and fast near-infrared (IR) light-triggered drug release was achieved with optimized phospholipid composition and a 1:50 ICG-to-lipid molar ratio. Encapsulated small molecular calcein and FITC-dextran (up to 20 kDa) were completely released from the liposomes after light exposure for 15 s. Location of ICG in the PEG layer of the liposomes was simulated with molecular dynamics. ICG has important benefits as a light-triggering agent in liposomes: fast content release, improved stability, improved possibility of liposomal size control, regulatory approval to use in humans, and the possibility of imaging the in vivo location of the liposomes based on the fluorescence of ICG. Near-infrared light used as a triggering mechanism has good tissue penetration and safety. Thus, ICG liposomes are an attractive option for light-controlled and efficient delivery of small and large drug molecules.

Hydraulic architecture and photosynthetic capacity as constraints on release from suppression in Douglas-fir and western hemlock.

Treesearch

Renninger H.J.; Meinzer F.C.; B.L. Gartner

2006-01-01

We compared hydraulic architecture, photosynthesis, and growth in Douglas-fir with that of a shade-tolerant western hemlock. The study was conducted in a site that had been thinned to release suppressed trees, and one that remained unthinned. Release seemed to be constrained initially by photosynthetic capacity in both species. After released trees increased their...

Influence of Nest Box Color and Release Sites on Osmia lignaria (Hymenoptera: Megachilidae) Reproductive Success in a Commercial Almond Orchard.

PubMed

Artz, Derek R; Allan, Matthew J; Wardell, Gordon I; Pitts-Singer, Theresa L

2014-12-01

Intensively managed, commercial orchards offer resources for managed solitary bees within agricultural landscapes and provide a means to study bee dispersal patterns, spatial movement, nest establishment, and reproduction. In 2012, we studied the impact of 1) the color of nest boxes covaried with four nest box density treatments and 2) the number of bee release sites covaried with two nest box density treatments on the reproductive success of Osmia lignaria Say in a California almond orchard pollinated by a mixture of O. lignaria and Apis mellifera L. Nest box color influenced the number of nests, total cells, and cells with male and female brood. More nests and cells were produced in light blue nest boxes than in orange or yellow nest boxes. The covariate nest box density also had a significant effect on brood production. The number of release sites did not affect O. lignaria nesting and reproduction, but the number of cavities in nest boxes influenced reproduction. Overall, the color of nest boxes and their distribution, but not the number of release sites, can greatly affect O. lignaria nest establishment and reproductive success in a commercial almond orchard. The ability to locate nesting sites in a homogenous, large orchard landscape may also be facilitated by the higher frequency of nest boxes with low numbers of cavities, and by the ability to detect certain nest box colors that best contrast with the blooming trees. © 2014 Entomological Society of America.

Modeling black-footed ferret energetics: Are southern release sites better?

USGS Publications Warehouse

Harrington, Lauren A.; Biggins, Dean E.; Alldredge, A. William

2006-01-01

Several models have been developed to estimate prey requirements and to assess habitat suitability of release sites for the black-footed ferret (Mustela nigripes) (e.g., Stromberg and others, 1983; Powell and others, 1985; Biggins and others, 1993). None of these models, however, addressed possible differences in energetic requirements between sites due to climatic differences within the ferret’s historical range. We used a simplified energetics model to examine the effect of variation in environmental conditions on ferret energetic requirements. The aim of the study was to determine whether the ferret might be more successful in one area than another.

Northeast Oregon Hatchery Project, Final Siting Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, Montgomery

1995-03-01

This report presents the results of site analysis for the Bonneville Power Administration Northeast Oregon Hatchery Project. The purpose of this project is to provide engineering services for the siting and conceptual design of hatchery facilities for the Bonneville Power Administration. The hatchery project consists of artificial production facilities for salmon and steelhead to enhance production in three adjacent tributaries to the Columbia River in northeast Oregon: the Grande Ronde, Walla Walla, and Imnaha River drainage basins. Facilities identified in the master plan include adult capture and holding facilities; spawning incubation, and early rearing facilities; full-term rearing facilities; and directmore » release or acclimation facilities. The evaluation includes consideration of a main production facility for one or more of the basins or several smaller satellite production facilities to be located within major subbasins. The historic and current distribution of spring and fall chinook salmon and steelhead was summarized for the Columbia River tributaries. Current and future production and release objectives were reviewed. Among the three tributaries, forty seven sites were evaluated and compared to facility requirements for water and space. Site screening was conducted to identify the sites with the most potential for facility development. Alternative sites were selected for conceptual design of each facility type. A proposed program for adult holding facilities, final rearing/acclimation, and direct release facilities was developed.« less

Carbon dioxide sequestration monitoring and verification via laser based detection system in the 2 mum band

NASA Astrophysics Data System (ADS)

Humphries, Seth David

Carbon Dioxide (CO2) is a known contributor to the green house gas effect. Emissions of CO2 are rising as the global demand for inexpensive energy is placated through the consumption and combustion of fossil fuels. Carbon capture and sequestration (CCS) may provide a method to prevent CO2 from being exhausted to the atmosphere. The carbon may be captured after fossil fuel combustion in a power plant and then stored in a long term facility such as a deep geologic feature. The ability to verify the integrity of carbon storage at a location is key to the success of all CCS projects. A laser-based instrument has been built and tested at Montana State University (MSU) to measure CO2 concentrations above a carbon storage location. The CO2 Detection by Differential Absorption (CODDA) Instrument uses a temperature-tunable distributed feedback (DFB) laser diode that is capable of accessing a spectral region, 2.0027 to 2.0042 mum, that contains three CO2 absorption lines and a water vapor absorption line. This instrument laser is aimed over an open-air, two-way path of about 100 m, allowing measurements of CO2 concentrations to be made directly above a carbon dioxide release test site. The performance of the instrument for carbon sequestration site monitoring is studied using a newly developed CO2 controlled release facility. The field and CO2 releases are managed by the Zero Emissions Research Technology (ZERT) group at MSU. Two test injections were carried out through vertical wells simulating seepage up well paths. Three test injections were done as CO2 escaped up through a slotted horizontal pipe simulating seepage up through geologic fault zones. The results from these 5 separate controlled release experiments over the course of three summers show that the CODDA Instrument is clearly capable of verifying the integrity of full-scale CO2 storage operations.

Caffeine Modulates Vesicle Release and Recovery at Cerebellar Parallel Fibre Terminals, Independently of Calcium and Cyclic AMP Signalling

PubMed Central

Dobson, Katharine L.; Jackson, Claire; Balakrishnan, Saju; Bellamy, Tomas C.

2015-01-01

Background Cerebellar parallel fibres release glutamate at both the synaptic active zone and at extrasynaptic sites—a process known as ectopic release. These sites exhibit different short-term and long-term plasticity, the basis of which is incompletely understood but depends on the efficiency of vesicle release and recycling. To investigate whether release of calcium from internal stores contributes to these differences in plasticity, we tested the effects of the ryanodine receptor agonist caffeine on both synaptic and ectopic transmission. Methods Whole cell patch clamp recordings from Purkinje neurons and Bergmann glia were carried out in transverse cerebellar slices from juvenile (P16-20) Wistar rats. Key Results Caffeine caused complex changes in transmission at both synaptic and ectopic sites. The amplitude of postsynaptic currents in Purkinje neurons and extrasynaptic currents in Bergmann glia were increased 2-fold and 4-fold respectively, but paired pulse ratio was substantially reduced, reversing the short-term facilitation observed under control conditions. Caffeine treatment also caused synaptic sites to depress during 1 Hz stimulation, consistent with inhibition of the usual mechanisms for replenishing vesicles at the active zone. Unexpectedly, pharmacological intervention at known targets for caffeine—intracellular calcium release, and cAMP signalling—had no impact on these effects. Conclusions We conclude that caffeine increases release probability and inhibits vesicle recovery at parallel fibre synapses, independently of known pharmacological targets. This complex effect would lead to potentiation of transmission at fibres firing at low frequencies, but depression of transmission at high frequency connections. PMID:25933382

Acetylcholine released from cholinergic nerves contributes to cutaneous vasodilation during heat stress

NASA Technical Reports Server (NTRS)

Shibasaki, Manabu; Wilson, Thad E.; Cui, Jian; Crandall, Craig G.

2002-01-01

Nitric oxide (NO) contributes to active cutaneous vasodilation during a heat stress in humans. Given that acetylcholine is released from cholinergic nerves during whole body heating, coupled with evidence that acetylcholine causes vasodilation via NO mechanisms, it is possible that release of acetylcholine in the dermal space contributes to cutaneous vasodilation during a heat stress. To test this hypothesis, in seven subjects skin blood flow (SkBF) and sweat rate were simultaneously monitored over three microdialysis membranes placed in the dermal space of dorsal forearm skin. One membrane was perfused with the acetylcholinesterase inhibitor neostigmine (10 microM), the second membrane was perfused with the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME; 10 mM) dissolved in the aforementioned neostigmine solution (l-NAME(Neo)), and the third membrane was perfused with Ringer solution as a control site. Each subject was exposed to approximately 20 min of whole body heating via a water-perfused suit, which increased mean body temperature from 36.4 +/- 0.1 to 37.5 +/- 0.1 degrees C (P < 0.05). After the heat stress, SkBF at each site was normalized to its maximum value, identified by administration of 28 mM sodium nitroprusside. Mean body temperature threshold for cutaneous vasodilation was significantly lower at the neostigmine-treated site relative to the other sites (neostigmine: 36.6 +/- 0.1 degrees C, l-NAME(Neo): 37.1 +/- 0.1 degrees C, control: 36.9 +/- 0.1 degrees C), whereas no significant threshold difference was observed between the l-NAME(Neo)-treated and control sites. At the end of the heat stress, SkBF was not different between the neostigmine-treated and control sites, whereas SkBF at the l-NAME(Neo)-treated site was significantly lower than the other sites. These results suggest that acetylcholine released from cholinergic nerves is capable of modulating cutaneous vasodilation via NO synthase mechanisms early in the heat stress but not after substantial cutaneous vasodilation.

Distribution of oceanic 137Cs from the Fukushima Dai-ichi Nuclear Power Plant simulated numerically by a regional ocean model.

PubMed

Tsumune, Daisuke; Tsubono, Takaki; Aoyama, Michio; Hirose, Katsumi

2012-09-01

Radioactive materials were released to the environment from the Fukushima Dai-ichi Nuclear Power Plant as a result of the reactor accident after the Tohoku earthquake and tsunami of 11 March 2011. The measured (137)Cs concentration in a seawater sample near the Fukushima Dai-ichi Nuclear Power Plant site reached 68 kBq L(-1) (6.8 × 10(4)Bq L(-1)) on 6 April. The two major likely pathways from the accident site to the ocean existed: direct release of high radioactive liquid wastes to the ocean and the deposition of airborne radioactivity to the ocean surface. By analysis of the (131)I/(137)Cs activity ratio, we determined that direct release from the site contributed more to the measured (137)Cs concentration than atmospheric deposition did. We then used a regional ocean model to simulate the (137)Cs concentrations resulting from the direct release to the ocean off Fukushima and found that from March 26 to the end of May the total amount of (137)Cs directly released was 3.5 ± 0.7 PBq ((3.5 ± 0.7) × 10(15)Bq). The simulated temporal change in (137)Cs concentrations near the Fukushima Daini Nuclear Power Plant site agreed well with observations. Our simulation results showed that (1) the released (137)Cs advected southward along the coast during the simulation period; (2) the eastward-flowing Kuroshio and its extension transported (137)C during May 2011; and (3) (137)Cs concentrations decreased to less than 10 BqL(-1) by the end of May 2011 in the whole simulation domain as a result of oceanic advection and diffusion. We compared the total amount and concentration of (137)Cs released from the Fukushima Dai-ichi reactors to the ocean with the (137)Cs released to the ocean by global fallout. Even though the measured (137)Cs concentration from the Fukushima accident was the highest recorded, the total released amount of (137)Cs was not very large. Therefore, the effect of (137)Cs released from the Fukushima Dai-ichi reactors on concentration in the whole North Pacific was smaller than that of past release events such as global fallout, and the amount of (137)Cs expected to reach other oceanic basins is negligible comparing with the past radioactive input. Copyright © 2011 Elsevier Ltd. All rights reserved.

Engineering Translational Activators with CRISPR-Cas System.

PubMed

Du, Pei; Miao, Chensi; Lou, Qiuli; Wang, Zefeng; Lou, Chunbo

2016-01-15

RNA parts often serve as critical components in genetic engineering. Here we report a design of translational activators which is composed of an RNA endoribonuclease (Csy4) and two exchangeable RNA modules. Csy4, a member of Cas endoribonuclease, cleaves at a specific recognition site; this cleavage releases a cis-repressive RNA module (crRNA) from the masked ribosome binding site (RBS), which subsequently allows the downstream translation initiation. Unlike small RNA as a translational activator, the endoribonuclease-based activator is able to efficiently unfold the perfect RBS-crRNA pairing. As an exchangeable module, the crRNA-RBS duplex was forwardly and reversely engineered to modulate the dynamic range of translational activity. We further showed that Csy4 and its recognition site, together as a module, can also be replaced by orthogonal endoribonuclease-recognition site homologues. These modularly structured, high-performance translational activators would endow the programming of gene expression in the translation level with higher feasibility.

Boldness towards novelty and translocation success in captive-raised, orphaned Tasmanian devils.

PubMed

Sinn, David L; Cawthen, Lisa; Jones, Susan M; Pukk, Chrissy; Jones, Menna E

2014-01-01

Translocation of endangered animals is common, but success is often variable and/or poor. Despite its intuitive appeal, little is known with regards to how individual differences amongst translocated animals influence their post-release survival, growth, and reproduction. We measured consistent pre-release responses to novelty in a familiar environment (boldness; repeatability=0.55) and cortisol response in a group of captive-reared Tasmanian devils, currently listed as "Endangered" by the IUCN. The devils were then released at either a hard- or soft-release site within their mothers' population of origin, and individual growth, movement, reproduction (females only), and survival across 2-8 months post-release was measured. Sex, release method, cohort, behavior, and cortisol response did not affect post-release growth, nor did these factors influence the home range size of orphan devils. Final linear distances moved from the release site were impacted heavily by the release cohort, but translocated devils' movement overall was not different from that in the same-age wild devils. All orphan females of reproductive age were subsequently captured with offspring. Overall survival rates in translocated devils were moderate (∼42%), and were not affected by devil sex, release method, cohort, release weight, or pre-release cortisol response. Devils that survived during the study period were, however, 3.5 times more bold than those that did not (effect size r=0.76). Our results suggest that conservation managers may need to provide developmental conditions in captivity that promote a wide range of behaviors across individuals slated for wild release. © 2013 Wiley Periodicals, Inc.

Analysis of multiple tank car releases in train accidents.

PubMed

Liu, Xiang; Liu, Chang; Hong, Yili

2017-10-01

There are annually over two million carloads of hazardous materials transported by rail in the United States. The American railroads use large blocks of tank cars to transport petroleum crude oil and other flammable liquids from production to consumption sites. Being different from roadway transport of hazardous materials, a train accident can potentially result in the derailment and release of multiple tank cars, which may result in significant consequences. The prior literature predominantly assumes that the occurrence of multiple tank car releases in a train accident is a series of independent Bernoulli processes, and thus uses the binomial distribution to estimate the total number of tank car releases given the number of tank cars derailing or damaged. This paper shows that the traditional binomial model can incorrectly estimate multiple tank car release probability by magnitudes in certain circumstances, thereby significantly affecting railroad safety and risk analysis. To bridge this knowledge gap, this paper proposes a novel, alternative Correlated Binomial (CB) model that accounts for the possible correlations of multiple tank car releases in the same train. We test three distinct correlation structures in the CB model, and find that they all outperform the conventional binomial model based on empirical tank car accident data. The analysis shows that considering tank car release correlations would result in a significantly improved fit of the empirical data than otherwise. Consequently, it is prudent to consider alternative modeling techniques when analyzing the probability of multiple tank car releases in railroad accidents. Copyright © 2017 Elsevier Ltd. All rights reserved.

NASA's Solar System Treks: Online Portals for Planetary Mapping and Modeling

NASA Technical Reports Server (NTRS)

Day, Brian

2017-01-01

NASA's Solar System Treks are a suite of web-based of lunar and planetary mapping and modeling portals providing interactive visualization and analysis tools enabling mission planners, planetary scientists, students, and the general public to access mapped lunar data products from past and current missions for the Moon, Mars, Vesta, and more. New portals for additional planetary bodies are being planned. This presentation will recap significant enhancements to these toolsets during the past year and look ahead to future features and releases. Moon Trek is a new portal replacing its predecessor, the Lunar Mapping and Modeling Portal (LMMP), that significantly upgrades and builds upon the capabilities of LMMP. It features greatly improved navigation, 3D visualization, fly-overs, performance, and reliability. Additional data products and tools continue to be added. These include both generalized products as well as polar data products specifically targeting potential sites for NASA's Resource Prospector mission as well as for missions being planned by NASA's international partners. The latest release of Mars Trek includes new tools and data products requested by NASA's Planetary Science Division to support site selection and analysis for Mars Human Landing Exploration Zone Sites. Also being given very high priority by NASA Headquarters is Mars Trek's use as a means to directly involve the public in upcoming missions, letting them explore the areas the agency is focusing upon, understand what makes these sites so fascinating, follow the selection process, and get caught up in the excitement of exploring Mars. Phobos Trek, the latest effort in the Solar System Treks suite, is being developed in coordination with the International Phobos/Deimos Landing Site Working Group, with landing site selection and analysis for JAXA's MMX (Martian Moons eXploration) mission as a primary driver.

NASA's Solar System Treks: Online Portals for Planetary Mapping and Modeling

NASA Astrophysics Data System (ADS)

Day, B. H.; Law, E.

2017-12-01

NASA's Solar System Treks are a suite of web-based of lunar and planetary mapping and modeling portals providing interactive visualization and analysis tools enabling mission planners, planetary scientists, students, and the general public to access mapped lunar data products from past and current missions for the Moon, Mars, Vesta, and more. New portals for additional planetary bodies are being planned. This presentation will recap significant enhancements to these toolsets during the past year and look ahead to future features and releases. Moon Trek is a new portal replacing its predecessor, the Lunar Mapping and Modeling Portal (LMMP), that significantly upgrades and builds upon the capabilities of LMMP. It features greatly improved navigation, 3D visualization, fly-overs, performance, and reliability. Additional data products and tools continue to be added. These include both generalized products as well as polar data products specifically targeting potential sites for NASA's Resource Prospector mission as well as for missions being planned by NASA's international partners. The latest release of Mars Trek includes new tools and data products requested by NASA's Planetary Science Division to support site selection and analysis for Mars Human Landing Exploration Zone Sites. Also being given very high priority by NASA Headquarters is Mars Trek's use as a means to directly involve the public in upcoming missions, letting them explore the areas the agency is focusing upon, understand what makes these sites so fascinating, follow the selection process, and get caught up in the excitement of exploring Mars. Phobos Trek, the latest effort in the Solar System Treks suite, is being developed in coordination with the International Phobos/Deimos Landing Site Working Group, with landing site selection and analysis for JAXA's MMX mission as a primary driver.

Life cycle based risk assessment of recycled materials in roadway construction.

PubMed

Carpenter, A C; Gardner, K H; Fopiano, J; Benson, C H; Edil, T B

2007-01-01

This paper uses a life-cycle assessment (LCA) framework to characterize comparative environmental impacts from the use of virgin aggregate and recycled materials in roadway construction. To evaluate site-specific human toxicity potential (HTP) in a more robust manner, metals release data from a demonstration site were combined with an unsaturated contaminant transport model to predict long-term impacts to groundwater. The LCA determined that there were reduced energy and water consumption, air emissions, Pb, Hg and hazardous waste generation and non-cancer HTP when bottom ash was used in lieu of virgin crushed rock. Conversely, using bottom ash instead of virgin crushed rock increased the cancer HTP risk due to potential leachate generation by the bottom ash. At this scale of analysis, the trade-offs are clearly between the cancer HTP (higher for bottom ash) and all of the other impacts listed above (lower for bottom ash). The site-specific analysis predicted that the contaminants (Cd, Cr, Se and Ag for this study) transported from the bottom ash to the groundwater resulted in very low unsaturated zone contaminant concentrations over a 200 year period due to retardation in the vadose zone. The level of contaminants predicted to reach the groundwater after 200 years was significantly less than groundwater maximum contaminant levels (MCL) set by the US Environmental Protection Agency for drinking water. Results of the site-specific contaminant release estimates vary depending on numerous site and material specific factors. However, the combination of the LCA and the site specific analysis can provide an appropriate context for decision making. Trade-offs are inherent in making decisions about recycled versus virgin material use, and regulatory frameworks should recognize and explicitly acknowledge these trade-offs in decision processes.

Internal and External Triggering Mechanism of "Smart" Nanoparticle-Based DDSs in Targeted Tumor Therapy.

PubMed

Qiana, Xian-Ling; Li, Jun; Wei, Ran; Lin, Hui; Xiong, Li-Xia

2018-05-09

Anticancer chemotherapeutics have a lot of problems via conventional drug delivery systems (DDSs), including non-specificity, burst release, severe side-effects, and damage to normal cells. Owing to its potential to circumventing these problems, nanotechnology has gained increasing attention in targeted tumor therapy. Chemotherapeutic drugs or genes encapsulated in nanoparticles could be used to target therapies to the tumor site in three ways: "passive", "active", and "smart" targeting. To summarize the mechanisms of various internal and external "smart" stimulating factors on the basis of findings from in vivo and in vitro studies. A thorough search of PubMed was conducted in order to identify the majority of trials, studies and novel articles related to the subject. Activated by internal triggering factors (pH, redox, enzyme, hypoxia, etc.) or external triggering factors (temperature, light of different wavelengths, ultrasound, magnetic fields, etc.), "smart" DDSs exhibit targeted delivery to the tumor site, and controlled release of chemotherapeutic drugs or genes. In this review article, we summarize and classify the internal and external triggering mechanism of "smart" nanoparticle-based DDSs in targeted tumor therapy, and the most recent research advances are illustrated for better understanding. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Towards a sterile insect technique field release of Anopheles arabiensis mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation

PubMed Central

Helinski, Michelle EH; Hassan, Mo'awia M; El-Motasim, Waleed M; Malcolm, Colin A; Knols, Bart GJ; El-Sayed, Badria

2008-01-01

Background The work described in this article forms part of a study to suppress a population of the malaria vector Anopheles arabiensis in Northern State, Sudan, with the Sterile Insect Technique. No data have previously been collected on the irradiation and transportation of anopheline mosquitoes in Africa, and the first series of attempts to do this in Sudan are reported here. In addition, experiments in a large field cage under near-natural conditions are described. Methods Mosquitoes were irradiated in Khartoum and transported as adults by air to the field site earmarked for future releases (400 km from the laboratory). The field cage was prepared for experiments by creating resting sites with favourable conditions. The mating and survival of (irradiated) laboratory males and field-collected males was studied in the field cage, and two small-scale competition experiments were performed. Results Minor problems were experienced with the irradiation of insects, mostly associated with the absence of a rearing facility in close proximity to the irradiation source. The small-scale transportation of adult mosquitoes to the release site resulted in minimal mortality (< 6%). Experiments in the field cage showed that mating occurred in high frequencies (i.e. an average of 60% insemination of females after one or two nights of mating), and laboratory reared males (i.e. sixty generations) were able to inseminate wild females at rates comparable to wild males. Based on wing length data, there was no size preference of males for mates. Survival of mosquitoes from the cage, based on recapture after mating, was satisfactory and approximately 60% of the insects were recaptured after one night. Only limited information on male competitiveness was obtained due to problems associated with individual egg laying of small numbers of wild females. Conclusion It is concluded that although conditions are challenging, there are no major obstacles associated with the small-scale irradiation and transportation of insects in the current setting. The field cage is suitable for experiments and studies to test the competitiveness of irradiated males can be pursued. The scaling up of procedures to accommodate much larger numbers of insects needed for a release is the next challenge and recommendations to further implementation of this genetic control strategy are presented. PMID:18439238

LC-MS/MS Peptide Mapping with Automated Data Processing for Routine Profiling of N-Glycans in Immunoglobulins

NASA Astrophysics Data System (ADS)

Shah, Bhavana; Jiang, Xinzhao Grace; Chen, Louise; Zhang, Zhongqi

2014-06-01

Protein N-Glycan analysis is traditionally performed by high pH anion exchange chromatography (HPAEC), reversed phase liquid chromatography (RPLC), or hydrophilic interaction liquid chromatography (HILIC) on fluorescence-labeled glycans enzymatically released from the glycoprotein. These methods require time-consuming sample preparations and do not provide site-specific glycosylation information. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) peptide mapping is frequently used for protein structural characterization and, as a bonus, can potentially provide glycan profile on each individual glycosylation site. In this work, a recently developed glycopeptide fragmentation model was used for automated identification, based on their MS/MS, of N-glycopeptides from proteolytic digestion of monoclonal antibodies (mAbs). Experimental conditions were optimized to achieve accurate profiling of glycoforms. Glycan profiles obtained from LC-MS/MS peptide mapping were compared with those obtained from HPAEC, RPLC, and HILIC analyses of released glycans for several mAb molecules. Accuracy, reproducibility, and linearity of the LC-MS/MS peptide mapping method for glycan profiling were evaluated. The LC-MS/MS peptide mapping method with fully automated data analysis requires less sample preparation, provides site-specific information, and may serve as an alternative method for routine profiling of N-glycans on immunoglobulins as well as other glycoproteins with simple N-glycans.

Short-term microbial release during rain events from on-site sewers and cattle in a surface water source.

PubMed

Aström, Johan; Pettersson, Thomas J R; Reischer, Georg H; Hermansson, Malte

2013-09-01

The protection of drinking water from pathogens such as Cryptosporidium and Giardia requires an understanding of the short-term microbial release from faecal contamination sources in the catchment. Flow-weighted samples were collected during two rainfall events in a stream draining an area with on-site sewers and during two rainfall events in surface runoff from a bovine cattle pasture. Samples were analysed for human (BacH) and ruminant (BacR) Bacteroidales genetic markers through quantitative polymerase chain reaction (qPCR) and for sorbitol-fermenting bifidobacteria through culturing as a complement to traditional faecal indicator bacteria, somatic coliphages and the parasitic protozoa Cryptosporidium spp. and Giardia spp. analysed by standard methods. Significant positive correlations were observed between BacH, Escherichia coli, intestinal enterococci, sulphite-reducing Clostridia, turbidity, conductivity and UV254 in the stream contaminated by on-site sewers. For the cattle pasture, no correlation was found between any of the genetic markers and the other parameters. Although parasitic protozoa were not detected, the analysis for genetic markers provided baseline data on the short-term faecal contamination due to these potential sources of parasites. Background levels of BacH and BacR makers in soil emphasise the need to including soil reference samples in qPCR-based analyses for Bacteroidales genetic markers.

Particle emissions from laboratory activities involving carbon nanotubes

NASA Astrophysics Data System (ADS)

Lo, Li-Ming; Tsai, Candace S.-J.; Heitbrink, William A.; Dunn, Kevin H.; Topmiller, Jennifer; Ellenbecker, Michael

2017-08-01

This site study was conducted in a chemical laboratory to evaluate nanomaterial emissions from 20-30-nm-diameter bundles of single-walled carbon nanotubes (CNTs) during product development activities. Direct-reading instruments were used to monitor the tasks in real time, and airborne particles were collected using various methods to characterize released nanomaterials using electron microscopy and elemental carbon (EC) analyses. CNT clusters and a few high-aspect-ratio particles were identified as being released from some activities. The EC concentration (0.87 μg/m3) at the source of probe sonication was found to be higher than other activities including weighing, mixing, centrifugation, coating, and cutting. Various sampling methods all indicated different levels of CNTs from the activities; however, the sonication process was found to release the highest amounts of CNTs. It can be cautiously concluded that the task of probe sonication possibly released nanomaterials into the laboratory and posed a risk of surface contamination. Based on these results, the sonication of CNT suspension should be covered or conducted inside a ventilated enclosure with proper filtration or a glovebox to minimize the potential of exposure.

Rehabilitation of Understocked Loblolly-Shortleaf Pine Stands - II. Development of Intermediate and Suppressed Trees Following Release in Natural Stands

Treesearch

James B. Baker; Michael G. Shelton

1998-01-01

Development of 86 intermediate and suppressed loblolly pine (Pinus taeda L.) trees, that had been recently released from overtopping pines and hardwoods, was monitored over a 15 year period. The trees were growing in natural stands on good sites (site index = 90 ft at 50 years) that had been recently cut to stocking levels ranging from 10 to 50 percent. At time of...

State of the Art of Stimuli-Responsive Liposomes for Cancer Therapy

PubMed Central

Heidarli, Elmira; Dadashzadeh, Simin; Haeri, Azadeh

2017-01-01

Specific delivery of therapeutic agents to solid tumors and their bioavailability at the target site are the most clinically important and challenging goals in cancer therapy. Liposomes are promising nanocarriers and have been well investigated for cancer therapy. In spite of preferred accumulation in tumors via the enhanced permeability and retention (EPR) effect, inefficient drug release at the target site and endosomal entrapment of long circulating liposomes are very important obstacles for achieving maximum anticancer efficacy. Thus, additional strategies such as stimulus-sensitive drug release are necessary to improve efficacy. Stimuli-sensitive liposomes are stable in blood circulation, however, activated by responding to external or internal stimuli and control the cargo release at the target site. This review focuses on state of the art of stimuli-responsive liposomes. Both external stimuli-responsive liposomes, including hyperthermia (HT), magnetic, light, and ultrasound-sensitive liposomes and internal stimuli (pH, reduction, and enzyme) responsive liposomes are covered. PMID:29552041

Sites of release of Putative Sex Pheromone and Sexual Behaviour in Female Carcinus maenas(Crustacea: Decapoda)

NASA Astrophysics Data System (ADS)

Bamber, S. D.; Naylor, E.

1997-02-01

Pre-moult female Carcinus maenasurine was confirmed as a source of putative sex pheromone. The sexual and temporal specificity of bioactivity in pre-moult female urine was demonstrated when urine samples taken from inter-moult and pre-moult male crabs, and inter-moult females, failed to generate a sexual response from receptive males. Detection sensitivity of male crabs to pre-moult female urine was established at a dilution factor of 1 μl of urine in 10 ml of seawater. Experimental blockage of the site of urine release (the antennal gland opercula) failed to diminish the chemical attractiveness of pre-moult female crabs to test males, implicating at least one further site of putative pheromone release. Observations of female sexual behaviour demonstrated an active role by pre-moult and post-moult female crabs when introduced to male crabs whose locomotor movement had been temporarily restricted.

State of the Art of Stimuli-Responsive Liposomes for Cancer Therapy.

PubMed

Heidarli, Elmira; Dadashzadeh, Simin; Haeri, Azadeh

2017-01-01

Specific delivery of therapeutic agents to solid tumors and their bioavailability at the target site are the most clinically important and challenging goals in cancer therapy. Liposomes are promising nanocarriers and have been well investigated for cancer therapy. In spite of preferred accumulation in tumors via the enhanced permeability and retention (EPR) effect, inefficient drug release at the target site and endosomal entrapment of long circulating liposomes are very important obstacles for achieving maximum anticancer efficacy. Thus, additional strategies such as stimulus-sensitive drug release are necessary to improve efficacy. Stimuli-sensitive liposomes are stable in blood circulation, however, activated by responding to external or internal stimuli and control the cargo release at the target site. This review focuses on state of the art of stimuli-responsive liposomes. Both external stimuli-responsive liposomes, including hyperthermia (HT), magnetic, light, and ultrasound-sensitive liposomes and internal stimuli (pH, reduction, and enzyme) responsive liposomes are covered.

Changes in solvation during DNA binding and cleavage are critical to altered specificity of the EcoRI endonuclease

PubMed Central

Robinson, Clifford R.; Sligar, Stephen G.

1998-01-01

Restriction endonucleases such as EcoRI bind and cleave DNA with great specificity and represent a paradigm for protein–DNA interactions and molecular recognition. Using osmotic pressure to induce water release, we demonstrate the participation of bound waters in the sequence discrimination of substrate DNA by EcoRI. Changes in solvation can play a critical role in directing sequence-specific DNA binding by EcoRI and are also crucial in assisting site discrimination during catalysis. By measuring the volume change for complex formation, we show that at the cognate sequence (GAATTC) EcoRI binding releases about 70 fewer water molecules than binding at an alternate DNA sequence (TAATTC), which differs by a single base pair. EcoRI complexation with nonspecific DNA releases substantially less water than either of these specific complexes. In cognate substrates (GAATTC) kcat decreases as osmotic pressure is increased, indicating the binding of about 30 water molecules accompanies the cleavage reaction. For the alternate substrate (TAATTC), release of about 40 water molecules accompanies the reaction, indicated by a dramatic acceleration of the rate when osmotic pressure is raised. These large differences in solvation effects demonstrate that water molecules can be key players in the molecular recognition process during both association and catalytic phases of the EcoRI reaction, acting to change the specificity of the enzyme. For both the protein–DNA complex and the transition state, there may be substantial conformational differences between cognate and alternate sites, accompanied by significant alterations in hydration and solvent accessibility. PMID:9482860

Cell density dependence of Microcystis aeruginosa responses to copper algaecide concentrations: Implications for microcystin-LR release.

PubMed

Kinley, Ciera M; Iwinski, Kyla J; Hendrikse, Maas; Geer, Tyler D; Rodgers, John H

2017-11-01

Along with mechanistic models, predictions of exposure-response relationships for copper are often derived from laboratory toxicity experiments with standardized experimental exposures and conditions. For predictions of copper toxicity to algae, cell density is a critical factor often overlooked. For pulse exposures of copper-based algaecides in aquatic systems, cell density can significantly influence copper sorbed by the algal population, and consequent responses. A cyanobacterium, Microcystis aeruginosa, was exposed to a copper-based algaecide over a range of cell densities to model the density-dependence of exposures, and effects on microcystin-LR (MC-LR) release. Copper exposure concentrations were arrayed to result in a gradient of MC-LR release, and masses of copper sorbed to algal populations were measured following exposures. While copper exposure concentrations eliciting comparable MC-LR release ranged an order of magnitude (24-h EC50s 0.03-0.3mg Cu/L) among cell densities of 10 6 through 10 7 cells/mL, copper doses (mg Cu/mg algae) were similar (24-h EC50s 0.005-0.006mg Cu/mg algae). Comparisons of MC-LR release as a function of copper exposure concentrations and doses provided a metric of the density dependence of algal responses in the context of copper-based algaecide applications. Combined with estimates of other site-specific factors (e.g. water characteristics) and fate processes (e.g. dilution and dispersion, sorption to organic matter and sediments), measuring exposure-response relationships for specific cell densities can refine predictions for in situ exposures and algal responses. These measurements can in turn decrease the likelihood of amending unnecessary copper concentrations to aquatic systems, and minimize risks for non-target aquatic organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

Centredale Manor Superfund Site in Rhode Island included on EPA List of Targeted for Immediate Attention

EPA Pesticide Factsheets

Today, the U.S. Environmental Protection Agency released the list of Superfund sites that Administrator Pruitt has targeted for immediate and intense attention. The Centredale Manor Restoration Project superfund site is one of the 21 sites on the list.

Peptides released by ameboid microglia regulate astroglial proliferation

PubMed Central

1985-01-01

Peptides that stimulate astroglial proliferation are produced in traumatized adult rat brain by 10 d after injury. These same peptides are released by ameboid microglia activated in vitro. Our findings suggest that astroglial scarring is regulated in part by the release of factors from ameboid microglia near the site of brain injury. PMID:4066764

Cheetahs (Acinonyx jubatus) running the gauntlet: an evaluation of translocations into free-range environments in Namibia.

PubMed

Weise, Florian J; Lemeris, Joseph R; Munro, Stuart J; Bowden, Andrew; Venter, Cicelia; van Vuuren, Marlice; van Vuuren, Rudie J

2015-01-01

Following dramatic range and population declines, the cheetah is Africa's most endangered large felid. In Namibia, private land managers still trap cheetahs but increasingly consider moving animals instead of killing them. Across Africa, managers have translocated perceived conflict carnivores for decades, but rarely evaluated their actions. We analyse the outcomes of 15 cheetah translocations (for 23 adults and 10 dependent offspring) into free-range environments in Namibia. We released cheetahs at an average distance of 419.6 km ± 216.1 km SD (range: 71-816 km) after captive periods ranging from 1-1,184 days (350.6 days ± 439.0 days SD). An individual's ability to survive the first year predominantly determined the overall translocation success of 40%. Post-release conflict and homing had less impact on success. Cheetah survival was lowest in the first three months after release. Human persecution (50% of deaths) and spotted hyaenas (29% of deaths) had the highest effect on survival. The degree of habituation to humans acquired during captivity significantly influenced chances of survival. Cheetahs surviving the initial post-release period (∼90 days) often settled into ranges and females reproduced successfully. However, all individuals exhibited extensive movements, frequently roaming >4,000 km(2) in the first six months after release (with a maximum of 19,743 km(2) in 112 days), resulting in low release site fidelity. Soft release and larger recipient area size did not improve site fidelity. Based on these outcomes, we evaluated which unfenced conservation areas in Namibia could potentially receive cheetahs. We found that there are currently few public and/or private reserves large enough to contain the movement profiles we observed in this study. This suggests that most translocations will result in cheetahs re-entering farmlands where they face a high risk of persecution. In conclusion, translocations into unconfined areas can successfully conserve individual cheetahs. Due to high mortality and unpredictable outcomes, however, conservation efforts need to focus on improving tolerance of cheetahs in commercial livestock and game farming areas in order to reduce the number of indiscriminately trapped animals.

Cheetahs (Acinonyx jubatus) running the gauntlet: an evaluation of translocations into free-range environments in Namibia

PubMed Central

Lemeris, Joseph R.; Munro, Stuart J.; Bowden, Andrew; Venter, Cicelia; van Vuuren, Marlice; van Vuuren, Rudie J.

2015-01-01

Following dramatic range and population declines, the cheetah is Africa’s most endangered large felid. In Namibia, private land managers still trap cheetahs but increasingly consider moving animals instead of killing them. Across Africa, managers have translocated perceived conflict carnivores for decades, but rarely evaluated their actions. We analyse the outcomes of 15 cheetah translocations (for 23 adults and 10 dependent offspring) into free-range environments in Namibia. We released cheetahs at an average distance of 419.6 km ± 216.1 km SD (range: 71–816 km) after captive periods ranging from 1–1,184 days (350.6 days ± 439.0 days SD). An individual’s ability to survive the first year predominantly determined the overall translocation success of 40%. Post-release conflict and homing had less impact on success. Cheetah survival was lowest in the first three months after release. Human persecution (50% of deaths) and spotted hyaenas (29% of deaths) had the highest effect on survival. The degree of habituation to humans acquired during captivity significantly influenced chances of survival. Cheetahs surviving the initial post-release period (∼90 days) often settled into ranges and females reproduced successfully. However, all individuals exhibited extensive movements, frequently roaming >4,000 km2 in the first six months after release (with a maximum of 19,743 km2 in 112 days), resulting in low release site fidelity. Soft release and larger recipient area size did not improve site fidelity. Based on these outcomes, we evaluated which unfenced conservation areas in Namibia could potentially receive cheetahs. We found that there are currently few public and/or private reserves large enough to contain the movement profiles we observed in this study. This suggests that most translocations will result in cheetahs re-entering farmlands where they face a high risk of persecution. In conclusion, translocations into unconfined areas can successfully conserve individual cheetahs. Due to high mortality and unpredictable outcomes, however, conservation efforts need to focus on improving tolerance of cheetahs in commercial livestock and game farming areas in order to reduce the number of indiscriminately trapped animals. PMID:26528410

Installation Restoration Program. Phase 1. Records Search for the Ohio National Guard, Rickenbacker Air National Guard Base, Columbus, Ohio.

DTIC Science & Technology

1987-06-01

Each of these sites involves POL releases, detection of which is amenable to geophysical/geochemi- cal methods . ES-8 I A I A I I I I ~ i I I ii I VN...Precipitation in Columbus, Ohio, averages 36.71 inches per year. By calcu- lating net precipitation according to the method outlined in the Federal Regis- ter...spill absorption devices. Fuel that was not recovered either evaporated, was absorbed into the ground, or entered the base drainage system from the west

Impact of methane flow through deformable lake sediments on atmospheric release

NASA Astrophysics Data System (ADS)

Scandella, B.; Juanes, R.

2010-12-01

Methane is a potent greenhouse gas that is generated geothermally and biologically in lake and ocean sediments. Free gas bubbles may escape oxidative traps and contribute more to the atmospheric source than dissolved methane, but the details of the methane release depend on the interactions between the multiple fluid phases and the deformable porous medium. We present a model and supporting laboratory experiments of methane release through “breathing” dynamic flow conduits that open in response to drops in the hydrostatic load on lake sediments, which has been validated against a high-resolution record of free gas flux and hydrostatic pressure in Upper Mystic Lake, MA. In contrast to previous linear elastic fracture mechanics analysis of gassy sediments, the evolution of gas transport in a deformable compliant sediment is presented within the framework of multiphase poroplasticity. Experiments address how strongly the mode and rate of gas flow, captured by our model, impacts the size of bubbles released into the water column. A bubble's size in turn determines how efficiently it transports methane to the atmosphere, and integrating this effect will be critical to improving estimates of the atmospheric methane source from lakes. Cross-sectional schematic of lake sediments showing two venting sites: one open at left and one closed at right. The vertical release of gas bubbles (red) at the open venting site creates a local pressure drop, which drives both bubble formation from the methane-rich pore water (higher concentrations shaded darker red) and lateral advection of dissolved methane (purple arrows). Even as bubbles in the open site escape, those at the closed site remain trapped.

Guidelines to site selection for population surveillance and mosquito control trials: a case study from Mauritius.

PubMed

Iyaloo, Diana P; Elahee, Khouaildi B; Bheecarry, Ambicadutt; Lees, Rosemary Susan

2014-04-01

Many novel approaches to controlling mosquito vectors through the release of sterile and mass reared males are being developed in the face of increasing insecticide resistance and other limitations of current methods. Before full scale release programmes can be undertaken there is a need for surveillance of the target population, and investigation of parameters such as dispersal and longevity of released, as compared to wild males through mark-release-recapture (MRR) and other experiments, before small scale pilot trials can be conducted. The nature of the sites used for this field work is crucial to ensure that a trial can feasibly collect sufficient and relevant information, given the available resources and practical limitations, and having secured the correct regulatory, community and ethical approvals and support. Mauritius is considering the inclusion of the sterile insect technique (SIT), for population reduction of Aedes albopictus, as a component of the Ministry of Health and Quality of Life's 'Operational Plan for Prevention and Control of Chikungunya and Dengue'. As part of an investigation into the feasibility of integrating the SIT into the Integrated Vector Management (IVM) scheme in Mauritius a pilot trial is planned. Two potential sites have been selected for this purpose, Pointe des Lascars and Panchvati, villages in the North East of the country, and population surveillance has commenced. This case study will here be used to explore the considerations which go into determining the most appropriate sites for mosquito field research. Although each situation is unique, and an ideal site may not be available, this discussion aims to help researchers to consider and balance the important factors and select field sites that will meet their needs. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.

Stimulation of Microbially Mediated Arsenic Release in Bangladesh Aquifers by Young Carbon Indicated by Radiocarbon Analysis of Sedimentary Bacterial Lipids.

PubMed

Whaley-Martin, K J; Mailloux, B J; van Geen, A; Bostick, B C; Silvern, R F; Kim, C; Ahmed, K M; Choudhury, I; Slater, G F

2016-07-19

The sources of reduced carbon driving the microbially mediated release of arsenic to shallow groundwater in Bangladesh remain poorly understood. Using radiocarbon analysis of phospholipid fatty acids (PLFAs) and potential carbon pools, the abundance and carbon sources of the active, sediment-associated, in situ bacterial communities inhabiting shallow aquifers (<30 m) at two sites in Araihazar, Bangladesh, were investigated. At both sites, sedimentary organic carbon (SOC) Δ(14)C signatures of -631 ± 54‰ (n = 12) were significantly depleted relative to dissolved inorganic carbon (DIC) of +24 ± 30‰ and dissolved organic carbon (DOC) of -230 ± 100‰. Sediment-associated PLFA Δ(14)C signatures (n = 10) at Site F (-167‰ to +20‰) and Site B (-163‰ to +21‰) were highly consistent and indicated utilization of carbon sources younger than the SOC, likely from the DOC pool. Sediment-associated PLFA Δ(14)C signatures were consistent with previously determined Δ(14)C signatures of microbial DNA sampled from groundwater at Site F indicating that the carbon source for these two components of the subsurface microbial community is consistent and is temporally stable over the two years between studies. These results demonstrate that the utilization of relatively young carbon sources by the subsurface microbial community occurs at sites with varying hydrology. Further they indicate that these young carbon sources drive the metabolism of the more abundant sediment-associated microbial communities that are presumably more capable of Fe reduction and associated release of As. This implies that an introduction of younger carbon to as of yet unaffected sediments (such as those comprising the deeper Pleistocene aquifer) could stimulate microbial communities and result in arsenic release.

Amchitka Mud Pit Sites 2006 Post-Closure Monitoring and Inspection Report, Amchitka Island, Alaska, Rev. No.: 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Patrick

2006-09-01

In 2001, the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA/NSO) remediated six areas associated with Amchitka mud pit release sites located on Amchitka Island, Alaska. This included the construction of seven closure caps. To ensure the integrity and effectiveness of remedial action, the mud pit sites are to be inspected every five years as part of DOE's long-term monitoring and surveillance program. In August of 2006, the closure caps were inspected in accordance with the ''Post-Closure Monitoring and Inspection Plan for Amchitka Island Mud Pit Release Sites'' (Rev. 0, November 2005). This post-closure monitoring report provides themore » 2006 cap inspection results.« less

BIOREMEDIATION TREATABILITY STUDIES OF CONTAMINATED SOILS AT WOOD PRESERVING SITES

EPA Science Inventory

Bioremediationis used frequently at sites contaminated with organic hazardous chemical where releases from processing vessels and the mismanagement of reagents and generated waste have contributed to significant impairment of the environment. At wood treater sites, process reagen...

NESHAP Area-Specific Dose-Release Factors for Potential Onsite Member-of-the-Public Locations at SRS using CAP88-PC Version 4.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trimor, P.

The Environmental Protection Agency (EPA) requires the use of the computer model CAP88-PC to estimate the total effective doses (TED) for demonstrating compliance with 40 CFR 61, Subpart H (EPA 2006), the National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. As such, CAP88 Version 4.0 was used to calculate the receptor dose due to routine atmospheric releases at the Savannah River Site (SRS). For estimation, NESHAP dose-release factors (DRFs) have been supplied to Environmental Compliance and Area Closure Projects (EC&ACP) for many years. DRFs represent the dose to a maximum receptor exposed to 1 Ci of a specified radionuclidemore » being released into the atmosphere. They are periodically updated to include changes in the CAP88 version, input parameter values, site meteorology, and location of the maximally exposed individual (MEI). In this report, the DRFs were calculated for potential radionuclide atmospheric releases from 13 SRS release points. The three potential onsite MEI locations to be evaluated are B-Area, Three Rivers Landfill (TRL), and Savannah River Ecology Lab Conference Center (SRELCC) with TRL’s onsite workers considered as members-of-the-public, and the potential future constructions of dormitories at SRELCC and Barracks at B-Area. Each MEI location was evaluated at a specified compass sector with different area to receptor distances and was conducted for both ground-level and elevated release points. The analysis makes use of area-specific meteorological data (Viner 2014). The resulting DRFs are compared to the 2014 NESHAP offsite MEI DRFs for three operational areas; A-Area, H-Area, and COS for a release rate of 1 Ci of tritium oxide at 0 ft. elevation. CAP88 was executed again using the 2016 NESHAP MEI release rates for 0 and 61 m stack heights to determine the radionuclide dose at TRL from the center-of-site (COS).« less

Mechanism of Mg2+-Accompanied Product Release in Sugar Nucleotidyltransferases.

PubMed

Vithani, Neha; Ankush Jagtap, Pravin Kumar; Verma, Sunil Kumar; Tripathi, Ravi; Awasthi, Shalini; Nair, Nisanth N; Prakash, Balaji

2018-03-06

The nucleotidyl transfer reaction, catalyzed by sugar nucleotidyltransferases (SNTs), is assisted by two active site Mg 2+ ions. While studying this reaction using X-ray crystallography, we captured snapshots of the pyrophosphate (product) as it exits along a pocket. Surprisingly, one of the active site Mg 2+ ions remains coordinated to the exiting pyrophosphate. This hints at the participation of Mg 2+ in the process of product release, besides its role in catalyzing nucleotidyl transfer. These observations are further supported by enhanced sampling molecular dynamics simulations. Free energy computations suggest that the product release is likely to be rate limiting in SNTs, and the origin of the high free energy barrier for product release could be traced back to the "slow" conformational change of an Arg residue at the exit end of the pocket. These results establish a dual role for Mg 2+ , and propose a general mechanism of product release during the nucleotidyl transfer by SNTs. Copyright © 2018 Elsevier Ltd. All rights reserved.

40 CFR 300.410 - Removal site evaluation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 27 2010-07-01 2010-07-01 false Removal site evaluation. 300.410... PLAN Hazardous Substance Response § 300.410 Removal site evaluation. (a) A removal site evaluation... evaluation of a release identified for possible CERCLA response pursuant to § 300.415 shall, as appropriate...

Stimulation of insulin release from the MIN6 cell line by a new imidazoline compound, S-21663: evidence for the existence of a novel imidazoline site in β cells

PubMed Central

Le Brigand, Laurence; Virsolvy, Anne; Peyrollier, Karine; Manechez, Dominique; Godfroid, Jean-Jacques; Guardiola-Lemaître, Béatrice; Bataille, Dominique

1997-01-01

The MIN6 cell line derived from in vivo immortalized insulin-secreting pancreatic β cells was used to study the insulin-releasing capacity and the cellular mode of action of S-21663, a newly synthesized imadizoline compound known for its antidiabetic effect in vivo and its ability to release insulin from perfused pancreas. S-21663, at concentrations ranging from 10−5 M to 10−3 M was able to release insulin from MIN6 cells; its activity peaked at 10−4 M, a drop in the stimulant factor being noted between 10−4 and 10−3 M. Its efficacy, which did not differ whatever the glucose concentration (stimulant or not), was higher than that of the other secretagogues tested, glucose, sulphonylureas or the peptide tGLP-1. In contrast to tGLP-1, S-21663 did not change the cyclic AMP content, whereas it increased Ca2+ influx via verapamil- and nifedipine-sensitive voltage-dependent calcium channels, the insulin release being a direct consequence of this Ca2+ entry. The S-21663-induced Ca2+ influx appears to be essentially the consequence of closure of K+ channels which differ from the ATP-dependent K+ (K-ATP) channels as determined by measurement of 86Rb efflux and use of a K-ATP channel opener. Comparison of the effects of S-21663 to that of efaroxan, another imidazoline compound shown to act on insulin release in a glucose-dependent way via binding sites distinct from the imidazoline I1 and I2 sites, suggested that S-21663 acts through a novel site which displays a remarkably stable expression along the cell culture. It is concluded that S-21663 is a very efficient, glucose-independent insulin secretagogue acting through a novel imidazoline site, linked to K+ channels, distinct from the I1, I2 and ‘efaroxan' binding sites. In vitro and in vivo features of S-21663 indicate that this compound, or new drugs drived from it, might be the basis for a new pharmacological approach to the mangement of type II (non insulin-dependent) diabetes. PMID:9375978

VizieR Online Data Catalog: LAMOST candidate members of star clusters (Xiang+, 2015)

NASA Astrophysics Data System (ADS)

Xiang, M. S.; Liu, X. W.; Yuan, H. B.; Huang, Y.; Huo, Z. Y.; Zhang, H. W.; Chen, B. Q.; Zhang, H. H.; Sun, N. C.; Wang, C.; Zhao, Y. H.; Shi, J. R.; Luo, A. L.; Li, G. P.; Wu, Y.; Bai, Z. R.; Zhang, Y.; Hou, Y. H.; Yuan, H. L.; Li, G. W.; Wei, Z.

2015-08-01

In this work, we describe the algorithms and implementation of LSP3, the LAMOST Stellar Parameter Pipeline at Peking University, a pipeline developed to determine the stellar parameters (radial velocity Vr, effective temperature Teff, surface gravity logg and metallicity [Fe/H]) from LAMOST spectra based on a template-matching technique. Following the data policy of LAMOST surveys, the data as well as the LSP3 pipeline will be public released as value-added products of the first data release of LAMOST (LAMOST DR1; Bai et al., 2015, A&A submitted), currently scheduled in 2014 December and can be accessed via http://lamost973.pku.edu.cn/site/node/4, along with a description file. (1 data file).

Dose commitments due to radioactive releases from nuclear power plant sites: Methodology and data base. Supplement 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

1996-06-01

This manual describes a dose assessment system used to estimate the population or collective dose commitments received via both airborne and waterborne pathways by persons living within a 2- to 80-kilometer region of a commercial operating power reactor for a specific year of effluent releases. Computer programs, data files, and utility routines are included which can be used in conjunction with an IBM or compatible personal computer to produce the required dose commitments and their statistical distributions. In addition, maximum individual airborne and waterborne dose commitments are estimated and compared to 10 CFR Part 50, Appendix 1, design objectives. Thismore » supplement is the last report in the NUREG/CR-2850 series.« less

40 CFR 280.63 - Initial site characterization.

Code of Federal Regulations, 2011 CFR

2011-07-01

... site investigations concerning the following factors: surrounding populations, water quality, use and approximate locations of wells potentially affected by the release, subsurface soil conditions, locations of...

Footprint, weathering, and persistence of synthetic-base drilling mud olefins in deep-sea sediments following the Deepwater Horizon disaster.

PubMed

Stout, Scott A; Payne, James R

2017-05-15

Olefin-based synthetic-based drilling mud (SBM) was released into the Gulf of Mexico as a result of the Deepwater Horizon (DWH) disaster in 2010. We studied the composition of neat SBM and, using conventional GC-FID, the extent, concentration, and chemical character of SBM-derived olefins in >3600 seafloor sediments collected in 2010/2011 and 2014. SBM-derived (C 14 -C 20 ) olefins occurred (up to 10cm deep) within a 6.5km 2 "footprint" around the well. The olefin concentration in most sediments decreased an order of magnitude between 2010/2011 and 2014, at least in part due to biodegradation, evidenced by the preferential loss C 16 and C 18 linear (α- and internal) versus branched olefins. Based on their persistence for 4-years in sediments around the Macondo well, and 13-years near a former unrelated drill site (~62km away), weathered SBM-derived olefins released during the DWH disaster are anticipated to persist in deep-sea sediment for (at least) a comparable duration. Copyright © 2017 Elsevier Ltd. All rights reserved.

pH-sensitive nanocargo based on smart polymer functionalized graphene oxide for site-specific drug delivery.

PubMed

Kavitha, Thangavelu; Abdi, Syed Izhar Haider; Park, Soo-Young

2013-04-14

Graphene oxide (GO) was functionalized covalently with pH-sensitive poly(2-(diethylamino) ethyl methacrylate) (PDEA) by surface-initiated in situ atom transfer radical polymerization. The structure of the PDEA-grafted GO (GO-PDEA) were examined by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and atomic force microscopy. The grafted PDEA endowed the GO sheets with good solubility and stability in physiological solutions. Simple physisorption by π-π stacking and hydrophobic interactions on GO-PDEA can be used to load camptothecin (CPT), a widely used water-insoluble cancer drug. The loaded CPT was released only at the lower (acidic) pH normally found in a tumor environment but not in basic and neutral pH. GO-PDEA did not show practical toxicity to N2a cancer cells but the GO-PDEA-CPT complex exhibited high potency in killing N2a cancer cells in vitro. These results suggest that the GO-PDEA nanocargo carrier might be a promising material for site-specific anticancer drug delivery and controlled release.

Simulation of in situ uranium bioremediation with slow-release organic amendment injection

NASA Astrophysics Data System (ADS)

Zhang, F.; Parker, J.; Ye, M.; Tang, G.; Wu, W.; Mehlhorn, T.; Gihring, T. M.; Schadt, C.; Watson, D. B.; Brooks, S. C.

2010-12-01

In situ bioremediation of a highly uranium-contaminated gravel aquifer with a slow-release electron donor (emulsified edible oil) has been investigated at the US DOE Oak Ridge Integrated Field Research Challenge (ORIFRC) site in east Tennessee. Groundwater at the study location has pH ~6.7 and contains high concentrations of U (5-6 μM), sulfate (1.0-1.2) mM and Ca (3-4 mM). Diluted emulsified oil (20% solution) was injected into three injection wells within 1.5 hrs. Geochemical analysis of site groundwater demonstrated the sequential reduction of nitrate, Mn, Fe(III) and sulfate. The oil was degraded by indigenous microorganisms with acetate as a major product. Rapid removal of U(VI) from the aqueous phase occurred concurrently with acetate production and sulfate reduction. The field test data were analyzed using a reaction network with a kinetic model for lipid hydrolysis and glycerol fermentation and equilibrium reactions representing microbial reduction of sulfate, nitrate, iron, uranium, manganese and carbon dioxide based on the thermodynamic approach of Istok et al. (2010) using the parallelized HGC5 code. Model-simulated chemical concentrations and relative abundance of functional microbial populations are compared with field measurements. Application of the thermodynamically-based modeling approach instead of the widely used multi-Monod kinetic rate law to formulate bioreduction reactions substantially reduces the number of reaction parameters that need to be calibrated thus facilitating a more comprehensive representation of microbial community dynamics. The model developed through this study is expected to aid the design of future bioremediation strategies for the site.

A spatial model with pulsed releases to compare strategies for the sterile insect technique applied to the mosquito Aedes aegypti.

PubMed

Oléron Evans, Thomas P; Bishop, Steven R

2014-08-01

We present a simple mathematical model to replicate the key features of the sterile insect technique (SIT) for controlling pest species, with particular reference to the mosquito Aedes aegypti, the main vector of dengue fever. The model differs from the majority of those studied previously in that it is simultaneously spatially explicit and involves pulsed, rather than continuous, sterile insect releases. The spatially uniform equilibria of the model are identified and analysed. Simulations are performed to analyse the impact of varying the number of release sites, the interval between pulsed releases and the overall volume of sterile insect releases on the effectiveness of SIT programmes. Results show that, given a fixed volume of available sterile insects, increasing the number of release sites and the frequency of releases increases the effectiveness of SIT programmes. It is also observed that programmes may become completely ineffective if the interval between pulsed releases is greater that a certain threshold value and that, beyond a certain point, increasing the overall volume of sterile insects released does not improve the effectiveness of SIT. It is also noted that insect dispersal drives a rapid recolonisation of areas in which the species has been eradicated and we argue that understanding the density dependent mortality of released insects is necessary to develop efficient, cost-effective SIT programmes. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Estimations of direct release rate of 137Cs and 90Sr to the ocean from the Fukushima Dai-ichi Nuclear Power Plant for five-and-a-half years

NASA Astrophysics Data System (ADS)

Tsumune, Daisuke; Aoyama, Michio; Tsubono, Takaki; Misumi, Kazuhiro; Tateda, Yutaka

2017-04-01

A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. Additional release pathways by river input and runoff from 1F NPP site with precipitation and were also effective for coastal zone in the specific periods before starting direct release on March 26 2011. Direct release from 1F NPP site is dominant one year after the accident. We estimated the direct release rate of 137Cs and 90Sr for more than five-and-a-half years after the accident by the Regional Ocean Model System (ROMS). Direct release rate of 137Cs were estimated for five-and-a-half years after the accident by comparing simulated results and measured activities adjacent to the 1F NPP site(at 5,6 discharge and south discharge). Directly release rate of 137Cs was estimated to be the order of magnitude of 1014 Bq/day and decreased exponentially with time to be the order of magnitude of 109 Bq/day by the end of September 2016. Estimated direct release rate have exponentially reduced with constant rate since November 2011. Apparent half-life of direct release rate was estimated to be 346 days. The estimated total amounts of directly released 137Cs was 3.7±0.7 PBq for five and a half years. Simulated 137Cs activities attributable to direct release were in good agreement with observed activities, a result that implies the estimated direct release rate was reasonable. Simulated 137Cs activity affected off coast in the Fukushima prefecture. We used the measured 137Cs activities by the Tokyo Electric Power Company (TEPCO) for the estimation of direct release. The sea water samples were corrected from the coast. The averaged 137Cs activities from November 2013 to June 2016 were 391 and 383 Bq/m3 at 5,6 discharge and south discharge, respectively. The averaged 137Cs activities measured by the Nuclear Regulation Agency (NRA) is about five times smaller than the one by the TEPCO because the NRA corrected seawater samples at 300-500m offshore by ship. Horizontal resolution of the model was 1km x 1km, therefore it is important to consider the difference of activities in the sub-grid scale for the detailed estimations of direct release. 90Sr/137Cs activity ratio measured adjacent to the 1F NPP is variable with time. The 90Sr/137Cs activity ratio was 0.62 due to the global fallout before the accident. The 90Sr/137Cs activity ratio decreased to 0.01 after the accident before April 2011. And the ratio increased to 1 by September 2013. And then the ratio decreased to 0.1-1. After October 2015, the ratio decreased to 0.1-0.2. Directly release rate of 90Sr was estimated to be the order of magnitude of 1012 Bq/day and decreased to the order of magnitude of 108 Bq/day by the end of September 2016. The estimated total amounts of directly released 90Sr was 35 ± 7 TBq.

Involvement of β3-adrenoceptors in the inhibitory control of cholinergic activity in human bladder: Direct evidence by [(3)H]-acetylcholine release experiments in the isolated detrusor.

PubMed

D' Agostino, Gianluigi; Maria Condino, Anna; Calvi, Paolo

2015-07-05

Bladder overactivity (OAB) is a multifactorial bladder disorder that requires therapeutics superior to the current pharmacological treatment with muscarinic antagonists. β3-adrenoceptor (β3-ADR) agonists represent a novel promising approach that differently addresses the parasympathetic pathway, but the clinical efficacy of these drugs has not been fully elucidated to date. Therefore, we aimed to study the pharmacological mechanisms activated by β3-ADR agonists at muscular and neural sites in the isolated human bladder. Detrusor smooth muscle strips obtained from male patients undergoing total cystectomy were labelled with tritiated choline and stimulated with electrical field stimulation (EFS). EFS produced smooth muscle contraction and simultaneous acetylcholine ([(3)H]-ACh) release, which mostly reflects the neural origin of acetylcholine. Isoprenaline (INA), BRL37344 and mirabegron inhibited the EFS-evoked contraction and [(3)H]-ACh release in a concentration-dependent manner, yielding concentration-response curves (CRCs) that were shifted to the right by the selective β3-ADR antagonists L-748,337 and SR59230A. Based on the agonist potency estimates (pEC50) and apparent affinities (pKb) of antagonists evaluated from the CRCs of agonists, our data confirm the occurrence of β3-ADRs at muscle sites. Moreover, our data are consistent with the presence of inhibitory β3-ADRs that are functionally expressed at the neural site. Taken together, these findings elucidate the mechanisms activated by β3-ADR agonists because neural β3-ADRs participate in the inhibition of detrusor motor drive by reducing the amount of acetylcholine involved in the cholinergic pathway. Copyright © 2015 Elsevier B.V. All rights reserved.

Assessment of trace element impacts on agricultural use of water from the Dan River following the Eden coal ash release.

PubMed

Hesterberg, Dean; Polizzotto, Matthew L; Crozier, Carl; Austin, Robert E

2016-04-01

Catastrophic events require rapid, scientifically sound decision making to mitigate impacts on human welfare and the environment. The objective of this study was to analyze potential impacts of coal ash-derived trace elements on agriculture following a 35,000-tonne release of coal ash into the Dan River at the Duke Energy Steam Station in Eden, North Carolina. We performed scenario calculations to assess the potential for excessive trace element loading to soils via irrigation and flooding with Dan River water, uptake of trace elements by crops, and livestock consumption of trace elements via drinking water. Concentrations of 13 trace elements measured in Dan River water samples within 4 km of the release site declined sharply after the release and were equivalent within 5 d to measurements taken upriver. Mass-balance calculations based on estimates of soil trace-element concentrations and the nominal river water concentrations indicated that irrigation or flooding with 25 cm of Dan River water would increase soil concentrations of all trace elements by less than 0.5%. Calculations of potential increases of trace elements in corn grain and silage, fescue, and tobacco leaves suggested that As, Cr, Se, Sr, and V were elements of most concern. Concentrations of trace elements measured in river water following the ash release never exceeded adopted standards for livestock drinking water. Based on our analyses, we present guidelines for safe usage of Dan River water to diminish negative impacts of trace elements on soils and crop production. In general, the approach we describe here may serve as a basis for rapid assessment of environmental and agricultural risks associated with any similar types of releases that arise in the future. © 2015 SETAC.

Sites in Mass. and Conn. are on EPA's Superfund Redevelopment Focus List

EPA Pesticide Factsheets

Today, the US EPA released its initial list of Superfund National Priorities List sites with the greatest expected redevelopment & commercial potential including two sites in New England: New Bedford Harbor in New Bedford, Mass. & Raymark Industries Inc.

Renton's Quendall Terminals on List of EPA Superfund Sites Targeted for Immediate, Intense Attention

EPA Pesticide Factsheets

EPA released the list of Superfund sites that Administrator Pruitt has targeted for intense and immediate attention, including the Quendall Terminals Site, a former creosote facility on the shore of Lake Washington in Renton, Washington.

Gaussian Processes for Prediction of Homing Pigeon Flight Trajectories

NASA Astrophysics Data System (ADS)

Mann, Richard; Freeman, Robin; Osborne, Michael; Garnett, Roman; Meade, Jessica; Armstrong, Chris; Biro, Dora; Guilford, Tim; Roberts, Stephen

2009-12-01

We construct and apply a stochastic Gaussian Process (GP) model of flight trajectory generation for pigeons trained to home from specific release sites. The model shows increasing predictive power as the birds become familiar with the sites, mirroring the animal's learning process. We show how the increasing similarity between successive flight trajectories can be used to infer, with increasing accuracy, an idealised route that captures the repeated spatial aspects of the bird's flight. We subsequently use techniques associated with reduced-rank GP approximations to objectively identify the key waypoints used by each bird to memorise its idiosyncratic habitual route between the release site and the home loft.

Assessment of radionuclide databases in CAP88 mainframe version 1.0 and Windows-based version 3.0.

PubMed

LaBone, Elizabeth D; Farfán, Eduardo B; Lee, Patricia L; Jannik, G Timothy; Donnelly, Elizabeth H; Foley, Trevor Q

2009-09-01

In this study the radionuclide databases for two versions of the Clean Air Act Assessment Package-1988 (CAP88) computer model were assessed in detail. CAP88 estimates radiation dose and the risk of health effects to human populations from radionuclide emissions to air. This program is used by several U.S. Department of Energy (DOE) facilities to comply with National Emission Standards for Hazardous Air Pollutants regulations. CAP88 Mainframe, referred to as version 1.0 on the U.S. Environmental Protection Agency Web site (http://www.epa.gov/radiation/assessment/CAP88/), was the very first CAP88 version released in 1988. Some DOE facilities including the Savannah River Site still employ this version (1.0) while others use the more user-friendly personal computer Windows-based version 3.0 released in December 2007. Version 1.0 uses the program RADRISK based on International Commission on Radiological Protection Publication 30 as its radionuclide database. Version 3.0 uses half-life, dose, and risk factor values based on Federal Guidance Report 13. Differences in these values could cause different results for the same input exposure data (same scenario), depending on which version of CAP88 is used. Consequently, the differences between the two versions are being assessed in detail at Savannah River National Laboratory. The version 1.0 and 3.0 database files contain 496 and 838 radionuclides, respectively, and though one would expect the newer version to include all the 496 radionuclides, 35 radionuclides are listed in version 1.0 that are not included in version 3.0. The majority of these has either extremely short or long half-lives or is no longer in production; however, some of the short-lived radionuclides might produce progeny of great interest at DOE sites. In addition, 122 radionuclides were found to have different half-lives in the two versions, with 21 over 3 percent different and 12 over 10 percent different.

A Mobile Aviary Design to Allow the Soft Release of Cavity Nesting Birds

Treesearch

Kathleen E. Franzreb

1997-01-01

Translocation of endangered red-cockaded woodpeckers (Picoides boreal is) has been an important component in restoration efforts to establish new populations and enlarge small populations. These efforts-relying on a "hard release" approach whereby the bird is captured, moved, and immediately released at the new site-have met with mixed results. A mobile...

The Relationship between Toxics Release Inventory Discharges and Mortality Rates in Rural and Urban Areas of the United States

ERIC Educational Resources Information Center

Hendryx, Michael; Fedorko, Evan

2011-01-01

Background: Potential environmental exposures from chemical manufacturing or industrial sites have not been well studied for rural populations. The current study examines whether chemical releases from facilities monitored through the Toxics Release Inventory (TRI) program are associated with population mortality rates for both rural and urban…

A novel approach to multihazard modeling and simulation.

PubMed

Smith, Silas W; Portelli, Ian; Narzisi, Giuseppe; Nelson, Lewis S; Menges, Fabian; Rekow, E Dianne; Mincer, Joshua S; Mishra, Bhubaneswar; Goldfrank, Lewis R

2009-06-01

To develop and apply a novel modeling approach to support medical and public health disaster planning and response using a sarin release scenario in a metropolitan environment. An agent-based disaster simulation model was developed incorporating the principles of dose response, surge response, and psychosocial characteristics superimposed on topographically accurate geographic information system architecture. The modeling scenarios involved passive and active releases of sarin in multiple transportation hubs in a metropolitan city. Parameters evaluated included emergency medical services, hospital surge capacity (including implementation of disaster plan), and behavioral and psychosocial characteristics of the victims. In passive sarin release scenarios of 5 to 15 L, mortality increased nonlinearly from 0.13% to 8.69%, reaching 55.4% with active dispersion, reflecting higher initial doses. Cumulative mortality rates from releases in 1 to 3 major transportation hubs similarly increased nonlinearly as a function of dose and systemic stress. The increase in mortality rate was most pronounced in the 80% to 100% emergency department occupancy range, analogous to the previously observed queuing phenomenon. Effective implementation of hospital disaster plans decreased mortality and injury severity. Decreasing ambulance response time and increasing available responding units reduced mortality among potentially salvageable patients. Adverse psychosocial characteristics (excess worry and low compliance) increased demands on health care resources. Transfer to alternative urban sites was possible. An agent-based modeling approach provides a mechanism to assess complex individual and systemwide effects in rare events.

Mark-recapture of Culex erythrothorax in Santa Cruz County, California.

PubMed

Tietze, Noor S; Stephenson, Mike F; Sidhom, Nader T; Binding, Paul L

2003-06-01

The dispersal of the tule mosquito, Culex erythrothorax, was studied in the proximity of Lake Tynan in the city of Watsonville, CA. From July 18 to 20, 2000, approximately 43,000 female Cx. erythrothorax were marked with luminous powder and released, using a distinct color each day. Recaptures were sampled by using 21 carbon dioxide-baited traps ranging in distance from zero to 2.8 km from the release site. During the 5 days of postrelease sampling, 319 marked mosquitoes were recaptured. The percentage of the marked mosquitoes that were recaptured was 0.46, 0.50, and 0.55% based on the 3 releases, respectively. Overall, the mosquitoes dispersed 0.57 km/day; the mean distance traveled increased during the 5-day sampling period from 0.42 km/day to 0.89 km/day from day 1 to day 5, respectively. Based on the Lincoln index, the estimated total population size for Cx. erythrothorax in the study area ranged from 3.8 to 94 million mosquitoes. This species was found to constitute a nuisance to local residents because of the abundance of this species and its capability to disperse into proximal communities.

A Reactive 1O2 - Responsive Combined Treatment System of Photodynamic and Chemotherapy for Cancer

NASA Astrophysics Data System (ADS)

Wang, Xiaojun; Meng, Guoqing; Zhang, Song; Liu, Xinli

2016-07-01

The development of reactive oxygen species (ROS)-responsive drug delivery and drug release has gradually attracted much attention in recent years as a promising therapeutic strategy. Singlet oxygen (1O2) as the major ROS species is widely used in photodynamic therapy (PDT) of cancer. In the present study, we introduce a combined treatment using ROS-sensitive thioketal (TK) linkage as a linker between upconversion nanoparticles (UNs)-based PDT and doxorubicin (DOX)-based chemotherapy. UNs can not only play a role in PDT, but can also be used as a nanocarrier for drug delivery of DOX. Moreover, the products of 1O2 during PDT are able to cleave TK linker inducing the release of DOX which can further achieve the goal of chemotherapy. By using this 1O2-responsive nanocarrier delivery system, DOX can easily reach the tumor site and be accumulated in the nuclei to effectively kill the cancer cells, and therefore decreasing the side effects of chemotherapy on the body. Thus, PDT also has the function of controlling drug release in this combination treatment strategy. Compared with monotherapy, the combination of PDT with chemotherapy also possesses excellent drug loading capability and anticancer efficiency.

Release of (14)C-labelled carbon nanotubes from polycarbonate composites.

PubMed

Rhiem, Stefan; Barthel, Anne-Kathrin; Meyer-Plath, Asmus; Hennig, Michael P; Wachtendorf, Volker; Sturm, Heinz; Schäffer, Andreas; Maes, Hanna M

2016-08-01

Waste disposal of carbon nanotube (CNT) containing products is expected to be the most important pathway for release of CNTs into the environment. In the present work, the use of radiolabelled CNTs ((14)C-CNT) for polycarbonate polymer nanocomposites with 1 wt% (14)C-CNT content allowed for the first time to quantify and differentiate the CNT release according to the type of impact along the materials' ageing history. After an initial exposure of the nanocomposite by solar-like irradiation, further environmental impacts were applied to composite material. They aimed at mimicking disposal site conditions that may induce further ageing effects and CNT release. This study included shaking in water, rapid temperature changes, soaking in humic acid solution as well as waste water effluent, and, finally, gentle mechanical abrasion. All ageing impacts were applied sequentially, both on pristine (control) and on solar-irradiated nanocomposites. All experiments were accompanied by absolute quantification of radioactive release as well as chemical and morphological analyses of the nanocomposite surfaces using infra-red (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The morphological analysis showed that spectral irradiation can uncover CNT networks on the outer nanocomposite surface layers by polymer degradation. After having subjected the solar-irradiated nanocomposite to all studied disposal site effect, the total radioactive release was quantified to amount to 64 mg CNT/m(2), whereas only 0.8 mg CNT/m(2) were found for the un-irradiated control sample. Solar degradation of polymers was thus found to significantly increase the propensity of the studied polymer nanocomposites to release CNTs during ageing effects at the product's end-of-life typical for disposal sites. Copyright © 2016. Published by Elsevier Ltd.

Field site leaching from recycled concrete aggregates applied as sub-base material in road construction.

PubMed

Engelsen, Christian J; Wibetoe, Grethe; van der Sloot, Hans A; Lund, Walter; Petkovic, Gordana

2012-06-15

The release of major and trace elements from recycled concrete aggregates used in an asphalt covered road sub-base has been monitored for more than 4 years. A similar test field without an asphalt cover, directly exposed to air and rain, and an asphalt covered reference field with natural aggregates in the sub-base were also included in the study. It was found that the pH of the infiltration water from the road sub-base with asphalt covered concrete aggregates decreased from 12.6 to below pH 10 after 2.5 years of exposure, whereas this pH was reached within only one year for the uncovered field. Vertical temperature profiles established for the sub-base, could explain the measured infiltration during parts of the winter season. When the release of major and trace elements as function of field pH was compared with pH dependent release data measured in the laboratory, some similar pH trends were found. The field concentrations of Cd, Ni, Pb and Zn were found to be low throughout the monitoring period. During two of the winter seasons, a concentration increase of Cr and Mo was observed, possibly due to the use of de-icing salt. The concentrations of the trace constituents did not exceed Norwegian acceptance criteria for ground water and surface water Class II. Copyright © 2012 Elsevier B.V. All rights reserved.

Aqueous geochemical data from the analysis of stream-water samples collected in June and July 2006-Taylor Mountains 1:250,00-scale quadrangle, Alaska

USGS Publications Warehouse

Wang, Bronwen; Mueller, Seth; Stetson, Sarah; Bailey, Elizabeth; Lee, Greg

2011-01-01

We report on the chemical analysis of water samples collected from the Taylor Mountains 1:250,000-scale quadrangle, Alaska. Parameters for which data are reported include pH, conductivity, water temperature, major cation and anion concentrations, trace-element concentrations, and dissolved organic-carbon concentrations. Samples were collected as part of a multiyear U.S. Geological Survey project entitled ?Geologic and Mineral Deposit Data for Alaskan Economic Development.? Data presented here are from samples collected in June and July 2006. The data are being released at this time with minimal interpretation. This is the third release of aqueous geochemical data from this project; aqueous geochemical data from samples collected in 2004 and 2005 were published previously. The data in this report augment but do not duplicate or supersede the previous data release. Site selection was based on a regional sampling strategy that focused on first- and second-order drainages. Water sample site selection was based on landscape parameters that included physiography, wetland extent, lithological changes, and a cursory field review of mineralogy from pan concentrates. Stream water in the Taylor Mountains quadrangle is dominated by bicarbonate (HCO3-), although in a few samples more than 50 percent of the anionic charge can be attributed to sulfate (SO42-). The major-cation chemistry ranges from Ca2+/Mg2+ dominated to a mix of Ca2+/Mg2+/Na++K+. Generally, good agreement was found between the major cations and anions in the duplicate samples. Many trace elements in these samples were at or near the analytical method detection limit, but good agreement was found between duplicate samples for elements with detectable concentrations. All field blank major-ion and trace-element concentrations were below detection.

Final Environmental Assessment for Proposed Construction II, Buckley Air Force Base, Colorado

DTIC Science & Technology

2004-06-01

Onopordum acanthium Scotch thistle Salsola sp. Russian thistle Tamarisk ramosissima Saltcedar Verbascum thapsus Mullein 3.7.4 Site-Specific...AFB by the City of Aurora. 3.10 RADON Radon is an odorless, tasteless radioactive gas. It is released by the breakdown of uranium -bearing deposits...such as sterile oats or winter wheat to establish root mass and compete with weeds • Follow sterile oats or winter wheat planting with mixed grass

A ground-based magnetic survey of Frenchman Flat, Nevada National Security Site and Nevada Test and Training Range, Nevada: data release and preliminary interpretation

USGS Publications Warehouse

Phillips, Jeffrey D.; Burton, Bethany L.; Curry-Elrod, Erika; Drellack, Sigmund

2014-01-01

Question 2—Does basin and range normal faulting observed in the hills north of Frenchman Flat continue southward under alluvium and possibly disrupt the Topopah Spring Tuff of the Paintbrush Group (the Topopah Spring welded tuff aquifer or TSA) east of the Pin Stripe underground nuclear test, which was conducted in Emplacement hole U11b?

Using Tree-Rings and Remote Sensing to Investigate Forest Productivity Response to Landscape Fragmentation in Northeastern Algeria

NASA Astrophysics Data System (ADS)

Rouini, N.; Lepley, K. S.; Messaoudene, M.

2017-12-01

Remote sensing and dendrochronology are valuable tools in the face of climate change and land use change, yet the connection between these resources remains largely unexploited. Research on forest fragmentation is mainly focused on animal groups, while our work focuses on tree communities. We link tree-rings and remotely-sensed Normalized Difference Vegetation Index (NDVI) using seasonal correlation analysis to investigate forest primary productivity response to fragmentation. Tree core samples from Quercus afares have been taken from two sites within the Guerrouche Forest in northeastern Algeria. The first site is located within a very fragmented area while the second site is intact. Fragmentation is estimated to have occurred with the construction of a road in 1930. We find raw tree-ring width chronologies from each site reveal growth release in the disturbed site after 1930. The means of each chronology for the 1930 to 2016 period are statistically different (p < 0.01). Based on these preliminary results we hypothesize that reconstructed primary productivity (NDVI) will be higher in the fragmented site after fragmentation took place.

Fate of biological control introductions: monitoring an Australian fungal pathogen of grasshoppers in North America.

PubMed Central

Bidochka, M J; Walsh, S R; Ramos, M E; St Leger, R J; Silver, J C; Roberts, D W

1996-01-01

In North America there are two generally recognized pathotypes (pathotypes 1 and 2) of the fungus Entomophaga grylli which show host-preferential infection of grasshopper subfamilies. Pathotype 3, discovered in Australia, has a broader grasshopper host range and was considered to be a good biocontrol agent. Between 1989 and 1991 pathotype 3 was introduced at two field sites in North Dakota. Since resting spores are morphologically indistinguishable among pathotypes, we used pathotype-specific DNA probes to confirm pathotype identification in E. grylli-infected grasshoppers collected at the release sites in 1992, 1993, and 1994. In 1992, up to 23% of E. grylli-infected grasshoppers of the subfamilies Melanoplinae, Oedipodinae, and Gomphocerinae were infected by pathotype 3, with no infections > 1 km from the release sites. In 1993, pathotype 3 infections declined to 1.7%. In 1994 grasshopper populations were low and no pathotype 3 infections were found. The frequency of pathotype 3 infection has declined to levels where its long-term survival in North America is questionable. Analyses of biocontrol releases are critical to evaluating the environmental risks associated with these ecological manipulations, and molecular probes are powerful tools for monitoring biocontrol releases. Images Fig. 1 PMID:8570660

Presynaptic imidazoline receptors and non-adrenoceptor[3H]-idazoxan binding sites in human cardiovascular tissues

PubMed Central

Molderings, G J; Likungu, J; Jakschik, J; Göthert, M

1997-01-01

In segments of human right atrial appendages and pulmonary arteries preincubated with [3H]-noradrenaline and superfused with physiological salt solution containing desipramine and corticosterone, the involvement of imidazoline receptors in the modulation of [3H]-noradrenaline release was investigated. In human atrial appendages, the guanidines aganodine and DTG (1,3-di(2-tolyl)guanidine) which activate presynaptic imidazoline receptors, inhibited electrically-evoked [3H]-noradrenaline release. The inhibition was not affected by blockade of α2-adrenoceptors with 1 μM rauwolscine, but antagonized by extremely high concentrations of this drug (10 and/or 30 μM; apparent pA2 against aganodine and DTG: 5.55 and 5.21, respectively). In the presence of 1 μM rauwolscine, [3H]-noradrenaline release in human atrial appendages was also inhibited by the imidazolines idazoxan and cirazoline, but not by agmatine and noradrenaline. The inhibitory effects of 100 μM idazoxan and 30 μM cirazoline were abolished by 30 μM rauwolscine. In the atrial appendages, the rank order of potency of all guanidines and imidazolines for their inhibitory effect on electrically-evoked [3H]-noradrenaline release in the presence of 1 μM rauwolscine was: aganodine⩾BDF 6143 [4-chloro-2-(2-imidazolin-2-yl-amino)-isoindoline]>DTG⩾clonidine>cirazoline>idazoxan (BDF 6143 and clonidine were previously studied under identical conditions). This potency order corresponded to that previously determined at the presynaptic imidazoline receptors in the rabbit aorta. When, in the experiments in the human pulmonary artery, rauwolscine was absent from the superfusion fluid, the concentration-response curve for BDF 6143 (a mixed α2-adrenoceptor antagonist/imidazoline receptor agonist) for its facilitatory effect on electrically-evoked [3H]-noradrenaline release was bell-shaped. In the presence of 1 μM rauwolscine, BDF 6143 and cirazoline concentration-dependently inhibited the evoked [3H]-noradrenaline release. In human atrial appendages, non-adrenoceptor [3H]-idazoxan binding sites were identified and characterized. The binding of [3H]-idazoxan was specific, reversible, saturable and of high affinity (KD: 25.5 nM). The specific binding of [3H]-idazoxan (defined by cirazoline 0.1 mM) to membranes of human atrial appendages was concentration-dependently inhibited by several imidazolines and guanidines, but not by rauwolscine and agmatine. In most cases, the competition curves were best fitted to a two-site model. The rank order of affinity for the high affinity site (in a few cases for the only detectable site; cirazoline=idazoxan>BDF 6143>DTG⩾clonidine) is compatible with the pharmacological properties of I2-imidazoline binding sites, but is clearly different from the rank order of potency for inhibiting evoked noradrenaline release from sympathetic nerves in the same tissue. It is concluded that noradrenaline release in the human atrium and, less well established, in the pulmonary artery is inhibited via presynaptic imidazoline receptors. These presynaptic imidazoline receptors appear to be related to those previously characterized in rabbit aorta and pulmonary artery, but differ clearly from I1 and I2 imidazoline binding sites. PMID:9298527

COSTS TO REMEDIATE MTBE-CONTAMINATED SITES

EPA Science Inventory

The extensive contamination of methyl tert-butyl ether (MTBE) in ground water has introduced concerns about the increased cost of remediation of MTBE releases compared to sites with BTEX only contamination. In an attempt to evaluate these costs, cost information for 311 sites wa...

Altered mechanisms underlying the abnormal glutamate release in amyotrophic lateral sclerosis at a pre-symptomatic stage of the disease.

PubMed

Bonifacino, Tiziana; Musazzi, Laura; Milanese, Marco; Seguini, Mara; Marte, Antonella; Gallia, Elena; Cattaneo, Luca; Onofri, Franco; Popoli, Maurizio; Bonanno, Giambattista

2016-11-01

Abnormal Glu release occurs in the spinal cord of SOD1(G93A) mice, a transgenic animal model for human ALS. Here we studied the mechanisms underlying Glu release in spinal cord nerve terminals of SOD1(G93A) mice at a pre-symptomatic disease stage (30days) and found that the basal release of Glu was more elevated in SOD1(G93A) with respect to SOD1 mice, and that the surplus of release relies on synaptic vesicle exocytosis. Exposure to high KCl or ionomycin provoked Ca(2+)-dependent Glu release that was likewise augmented in SOD1(G93A) mice. Equally, the Ca(2+)-independent hypertonic sucrose-induced Glu release was abnormally elevated in SOD1(G93A) mice. Also in this case, the surplus of Glu release was exocytotic in nature. We could determine elevated cytosolic Ca(2+) levels, increased phosphorylation of Synapsin-I, which was causally related to the abnormal Glu release measured in spinal cord synaptosomes of pre-symptomatic SOD1(G93A) mice, and increased phosphorylation of glycogen synthase kinase-3 at the inhibitory sites, an event that favours SNARE protein assembly. Western blot experiments revealed an increased number of SNARE protein complexes at the nerve terminal membrane, with no changes of the three SNARE proteins and increased expression of synaptotagmin-1 and β-Actin, but not of an array of other release-related presynaptic proteins. These results indicate that the abnormal exocytotic Glu release in spinal cord of pre-symptomatic SOD1(G93A) mice is mainly based on the increased size of the readily releasable pool of vesicles and release facilitation, supported by plastic changes of specific presynaptic mechanisms. Copyright © 2016 Elsevier Inc. All rights reserved.

Designing a community engagement framework for a new dengue control method: a case study from central Vietnam.

PubMed

McNaughton, Darlene; Duong, Thi Thu Huong

2014-05-01

The Wolbachia strategy aims to manipulate mosquito populations to make them incapable of transmitting dengue viruses between people. To test its efficacy, this strategy requires field trials. Public consultation and engagement are recognized as critical to the future success of these programs, but questions remain regarding how to proceed. This paper reports on a case study where social research was used to design a community engagement framework for a new dengue control method, at a potential release site in central Vietnam. The approach described here, draws on an anthropological methodology and uses both qualitative and quantitative methods to design an engagement framework tailored to the concerns, expectations, and socio-political setting of a potential trial release site for Wolbachia-infected Aedes aegypti mosquitoes. The process, research activities, key findings and how these were responded to are described. Safety of the method to humans and the environment was the most common and significant concern, followed by efficacy and impact on local lives. Residents expected to be fully informed and engaged about the science, the project, its safety, the release and who would be responsible should something go wrong. They desired a level of engagement that included regular updates and authorization from government and at least one member of every household at the release site. Results demonstrate that social research can provide important and reliable insights into public concerns and expectations at a potential release site, as well as guidance on how these might be addressed. Findings support the argument that using research to develop more targeted, engagement frameworks can lead to more sensitive, thorough, culturally comprehensible and therefore ethical consultation processes. This approach has now been used successfully to seek public input and eventually support for releases Wolbachia-infected mosquitoes, in two different international settings--Australia and Vietnam.

Dual interaction of agmatine with the rat α2D-adrenoceptor: competitive antagonism and allosteric activation

PubMed Central

Molderings, G J; Menzel, S; Kathmann, M; Schlicker, E; Göthert, M

2000-01-01

In segments of rat vena cava preincubated with [3H]-noradrenaline and superfused with physiological salt solution, the influence of agmatine on the electrically evoked [3H]-noradrenaline release, the EP3 prostaglandin receptor-mediated and the α2D-adrenoceptor-mediated inhibition of evoked [3H]-noradrenaline release was investigated. Agmatine (0.1–10 μM) by itself was without effect on evoked [3H]-noradrenaline release. In the presence of 10 μM agmatine, the prostaglandin E2(PGE2)-induced EP3-receptor-mediated inhibition of [3H]-noradrenaline release was not modified, whereas the α2D-adrenoceptor-mediated inhibition of [3H]-noradrenaline release induced by noradrenaline, moxonidine or clonidine was more pronounced than in the absence of agmatine. However, 1 mM agmatine antagonized the moxonidine-induced inhibition of [3H]-noradrenaline release. Agmatine concentration-dependently inhibited the binding of [3H]-clonidine and [3H]-rauwolscine to rat brain cortex membranes (Ki values 6 μM and 12 μM, respectively). In addition, 30 and 100 μM agmatine increased the rate of association and decreased the rate of dissociation of [3H]-clonidine resulting in an increased affinity of the radioligand for the α2D-adrenoceptors. [14C]-agmatine labelled specific binding sites on rat brain cortex membranes. In competition experiments. [14C]-agmatine was inhibited from binding to its specific recognition sites by unlabelled agmatine, but not by rauwolscine and moxonidine. In conclusion, the present data indicate that agmatine both acts as an antagonist at the ligand recognition site of the α2D-adrenoceptor and enhances the effects of α2-adrenoceptor agonists probably by binding to an allosteric binding site of the α2D-adrenoceptor which seems to be labelled by [14C]-agmatine. PMID:10928978

Designing a Community Engagement Framework for a New Dengue Control Method: A Case Study from Central Vietnam

PubMed Central

McNaughton, Darlene; Duong, Thi Thu Huong

2014-01-01

Background The Wolbachia strategy aims to manipulate mosquito populations to make them incapable of transmitting dengue viruses between people. To test its efficacy, this strategy requires field trials. Public consultation and engagement are recognized as critical to the future success of these programs, but questions remain regarding how to proceed. This paper reports on a case study where social research was used to design a community engagement framework for a new dengue control method, at a potential release site in central Vietnam. Methodology/Principal Findings The approach described here, draws on an anthropological methodology and uses both qualitative and quantitative methods to design an engagement framework tailored to the concerns, expectations, and socio-political setting of a potential trial release site for Wolbachia-infected Aedes aegypti mosquitoes. The process, research activities, key findings and how these were responded to are described. Safety of the method to humans and the environment was the most common and significant concern, followed by efficacy and impact on local lives. Residents expected to be fully informed and engaged about the science, the project, its safety, the release and who would be responsible should something go wrong. They desired a level of engagement that included regular updates and authorization from government and at least one member of every household at the release site. Conclusions/Significance Results demonstrate that social research can provide important and reliable insights into public concerns and expectations at a potential release site, as well as guidance on how these might be addressed. Findings support the argument that using research to develop more targeted, engagement frameworks can lead to more sensitive, thorough, culturally comprehensible and therefore ethical consultation processes. This approach has now been used successfully to seek public input and eventually support for releases Wolbachia-infected mosquitoes, in two different international settings - Australia and Vietnam. PMID:24853391

On the possible leakage of ET-RR1 liquid waste tank: hydrological and migration modes studies.

PubMed

Mahmoud, N S; El-Hemamy, S T

2005-03-20

The first Egyptian (ET-RR1) research reactor has been in operation since 1961 at the Egyptian Atomic Energy Authority (EAEA) Inshas site. Therefore, at present, it faces a serious problem due to aging equipment, especially those directly in contact with the environment such as the underground settling tanks of nuclear and radioactive waste. The possible leakage of radionuclides from these aging tanks and their migration to the aquifer was studied using instantaneous release. This study was done based on the geological and hydrological characteristics of the site, which were obtained from the hydrogeological data of 25 wells previously drilled at the site of the reactor[1]. These data were used to calculate the trend of water levels, hydraulic gradient, and formulation of water table maps from 1993-2002. This information was utilized to determine water velocity in the unsaturated zone. Radionuclides released from the settling tank to the aquifer were screened according to the radionuclides that have high migration ability and high activity. The amount of fission and activation products of the burned fuels that contaminated the water content of the reactor pool were considered as 10% of the original spent fuel. The radionuclides considered in this case were H-3, Sr-90, Zr-93, Tc-99, Cd-113, Cs-135, Cs-137, Sm-151, Pu-238, Pu-240, Pu-241, and Am-241. The instantaneous release was analyzed by theoretical calculations, taking into consideration the migration mechanism of the various radionuclides through the soil space between the tank bottom and the aquifer. The migration mechanism through the unsaturated zone was considered depending on soil type, thickness of the unsaturated zone, water velocity, and other factors that are specific for each radionuclide, namely retardation factor, which is the function of the specific distribution coefficient of each radionuclide. This was considered collectively as delay time. Meanwhile, the mechanism of radionuclide migration during their passage in the water body of the aquifer was the main focus of this study. The degree of water pollution in the aquifer at a point of contact with the main water body of Ismailia Canal 1000 m from the reactor site was assessed for the instantaneous release by comparing the results obtained with the regulations of the standard limit of radionuclides in drinking water.

On The Possible Leakage of ET-RR1 Liquid Waste Tank: Hydrological and Migration Modes Studies

PubMed Central

Mahmoud, N. S.; EL-Hemamy, S. T.

2005-01-01

The first Egyptian (ET-RR1) research reactor has been in operation since 1961 at the Egyptian Atomic Energy Authority (EAEA) Inshas site. Therefore, at present, it faces a serious problem due to aging equipment, especially those directly in contact with the environment such as the underground settling tanks of nuclear and radioactive waste. The possible leakage of radionuclides from these aging tanks and their migration to the aquifer was studied using instantaneous release.This study was done based on the geological and hydrological characteristics of the site, which were obtained from the hydrogeological data of 25 wells previously drilled at the site of the reactor[1]. These data were used to calculate the trend of water levels, hydraulic gradient, and formulation of water table maps from 1993–2002. This information was utilized to determine water velocity in the unsaturated zone.Radionuclides released from the settling tank to the aquifer were screened according to the radionuclides that have high migration ability and high activity. The amount of fission and activation products of the burned fuels that contaminated the water content of the reactor pool were considered as 10% of the original spent fuel. The radionuclides considered in this case were H-3, Sr-90, Zr-93, Tc-99, Cd-113, Cs-135, Cs-137, Sm-151, Pu-238, Pu-240, Pu-241, and Am-241.The instantaneous release was analyzed by theoretical calculations, taking into consideration the migration mechanism of the various radionuclides through the soil space between the tank bottom and the aquifer. The migration mechanism through the unsaturated zone was considered depending on soil type, thickness of the unsaturated zone, water velocity, and other factors that are specific for each radionuclide, namely retardation factor, which is the function of the specific distribution coefficient of each radionuclide. This was considered collectively as delay time. Meanwhile, the mechanism of radionuclide migration during their passage in the water body of the aquifer was the main focus of this study.The degree of water pollution in the aquifer at a point of contact with the main water body of Ismailia Canal 1000 m from the reactor site was assessed for the instantaneous release by comparing the results obtained with the regulations of the standard limit of radionuclides in drinking water[2,3]. PMID:15798884

Masters or slaves? Vesicle release machinery and the regulation of presynaptic calcium channels.

PubMed

Jarvis, Scott E; Zamponi, Gerald W

2005-05-01

Calcium entry through presynaptic voltage-gated calcium channels is essential for neurotransmitter release. The two major types of presynaptic calcium channels contain a synaptic protein interaction site that physically interacts with synaptic vesicle release proteins. This is thought to tighten the coupling between the sources of calcium entry and the neurotransmitter release machinery. Conversely, the binding of synaptic proteins to presynaptic calcium channels regulates calcium channel activity. Hence, presynaptic calcium channels act not only as the masters of the synaptic release process, but also as key targets for feedback inhibition.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cathy Wills

The Nevada Test Site Environmental Report 2006 (NTSER) was prepared to meet the information needs of the public and the requirements and guidelines of the U.S. Department of Energy (DOE) for annual site environmental reports. It was prepared by National Security Technologies, LLC (NSTec). This Executive Summary presents the purpose of the document, the major programs conducted at the Nevada Test Site (NTS), NTS key environmental initiatives, radiological releases and potential doses to the public resulting from site operations, a summary of nonradiological releases, implementation status of the NTS Environmental Management System, a summary of compliance with environmental regulations, pollutionmore » prevention and waste minimization accomplishments, and significant environmental accomplishments. Much of the content of this Executive Summary is also presented in a separate stand-alone pamphlet titled Nevada Test Site Environmental Report Summary 2006 produced to be a more cost-effective means of distributing information contained in the NTSER to interested DOE stakeholders.« less

Can hunting of translocated nuisance Canada geese reduce local conflicts?

USGS Publications Warehouse

Holevinski, R.A.; Malecki, R.A.; Curtis, P.D.

2006-01-01

Resident Canada geese (Branta canadensis) nest or reside in the temperate latitudes of North America. In past years, translocation-the capture and subsequent release of geese at distant locations-has been used to establish resident goose populations and to reduce nuisance problems. However, with new special hunting seasons designed to target resident Canada geese, we can now evaluate translocation as a management tool when hunting is allowed at release sites. We selected 2 study sites, representative of urban and suburban locations with nuisance resident geese, in central and western New York, USA. In June 2003, we translocated 80 neck-banded adult geese, 14 radiomarked adult females, and 83 juveniles 150 km east and southwest from urban and suburban problem sites in western New York to state-owned Wildlife Management Areas. At these same capture sites, we used 151 neck-banded adult geese, 12 radiomarked females, and 100 juveniles as controls to compare dispersal movements and harvest vulnerability to translocated geese. All observations (n = 45) of translocated radiomarked geese were <20 km from release sites, in areas where hunting was permitted. Only 25 of 538 observations (4.6%) of radiomarked geese at control sites were in areas open to hunting. The remainder of observations occurred at nonhunting locations within 10 km of control sites. More translocated adult geese (23.8%) were harvested than control geese (6.6%; ??2 = 72.98, P = 0.0009). More translocated juvenile geese were harvested (22.9%) than juvenile controls (5.0%; ??2 = 72.30, P = 0.0005). Only 7 (8.8%) translocated adult geese returned to the original capture sites during Canada goose hunting seasons. Translocation of adult and juvenile geese in family groups may alleviate nuisance problems at conflict sites through increased harvest, reducing the number of birds returning in subsequent years.

Methods of Soft Tissue Emulsification Using a Mechanism of Ultrasonic Atomization Inside Gas or Vapor Cavities and Associated Systems and Devices

NASA Technical Reports Server (NTRS)

Bailey, Michael R. (Inventor); Simon, Julianna C. (Inventor); Crum, Lawrence A. (Inventor); Khokhlova, Vera A. (Inventor); Wang, Yak-Nam (Inventor); Sapozhnikov, Oleg A. (Inventor); Khokhlova, Tatiana D. (Inventor)

2016-01-01

The present technology is directed to methods of soft tissue emulsification using a mechanism of ultrasonic atomization inside gas or vapor cavities, and associated systems and devices. In several embodiments, for example, a method of non-invasively treating tissue includes pulsing ultrasound energy from the ultrasound source toward the target site in tissue. The ultrasound source is configured to emit high intensity focused ultrasound (HIFU) waves. The target site comprises a pressure-release interface of a gas or vapor cavity located within the tissue. The method continues by generating shock waves in the tissue to induce a lesion in the tissue at the target site. The method additionally includes characterizing the lesion based on a degree of at least one of a mechanical or thermal ablation of the tissue.

KSC01pp0682

NASA Image and Video Library

2001-04-03

KENNEDY SPACE CENTER, FLA. -- The weight of an adult manatee requires a hoist to lift it out of the van for release into the Banana River. The site is on the north side of the NASA Causeway, near Kennedy Space Center. Sea World workers also released a calf at the site. The two manatees recovered from injuries at the Central Florida theme park. Manatees are frequently seen in the waters around Kennedy Space Center, which is surrounded by the Merritt Island National Wildlife Refuge

Volatile-rich lunar soil - Evidence of possible cometary impact.

NASA Technical Reports Server (NTRS)

Gibson, E. K., Jr.; Moore, G. W.

1973-01-01

A subsurface Apollo 16 soil, 61221, is much richer in volatile compounds than soils from any other locations or sites as shown by thermal analysis-gas release measurements. A weight loss of 0.03% during the interval 175 to 350 C was associated with the release of water, carbon dioxide, methane, hydrogen cyanide, hydrogen, and minor amounts of hydrocarbons and other species. These volatile components may have been brought to this site by a comet, which may have formed North Ray crater.

Development of a high-throughput crystal structure-determination platform for JAK1 using a novel metal-chelator soaking system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caspers, Nicole L.; Han, Seungil; Rajamohan, Francis

2016-10-27

Crystals of phosphorylated JAK1 kinase domain were initially generated in complex with nucleotide (ADP) and magnesium. The tightly bound Mg 2+-ADP at the ATP-binding site proved recalcitrant to ligand displacement. Addition of a molar excess of EDTA helped to dislodge the divalent metal ion, promoting the release of ADP and allowing facile exchange with ATP-competitive small-molecule ligands. Many kinases require the presence of a stabilizing ligand in the ATP site for crystallization. This procedure could be useful for developing co-crystallization systems with an exchangeable ligand to enable structure-based drug design of other protein kinases.

Population and habitat viability assessment for the Wyoming toad (Bufo baxteri): Final workshop report

USGS Publications Warehouse

2001-01-01

The Wyoming toad was listed as an endangered species under the Endangered Species Act on January 17, 1984, with a recovery plan approved in 1991. Currently the total population of the Wyoming toad includes approximately 200 animals in the captive breeding program and as few as 62 toads surviving at reintroduction sites in the Laramie Basin based upon fall 2000 survey data (after releases of more than 10,000 toads and tadpoles since 1995). Necessary conservation measures include improving reproduction and survival in the captive breeding program, improving survival at reintroduction sites, developing techniques to control the effects of the amphibian chytrid fungus, and eliminating threats and further habitat degradation in the wild.

High Throughput Measurement of Extracellular DNA Release and Quantitative NET Formation in Human Neutrophils In Vitro.

PubMed

Sil, Payel; Yoo, Dae-Goon; Floyd, Madison; Gingerich, Aaron; Rada, Balazs

2016-06-18

Neutrophil granulocytes are the most abundant leukocytes in the human blood. Neutrophils are the first to arrive at the site of infection. Neutrophils developed several antimicrobial mechanisms including phagocytosis, degranulation and formation of neutrophil extracellular traps (NETs). NETs consist of a DNA scaffold decorated with histones and several granule markers including myeloperoxidase (MPO) and human neutrophil elastase (HNE). NET release is an active process involving characteristic morphological changes of neutrophils leading to expulsion of their DNA into the extracellular space. NETs are essential to fight microbes, but uncontrolled release of NETs has been associated with several disorders. To learn more about the clinical relevance and the mechanism of NET formation, there is a need to have reliable tools capable of NET quantitation. Here three methods are presented that can assess NET release from human neutrophils in vitro. The first one is a high throughput assay to measure extracellular DNA release from human neutrophils using a membrane impermeable DNA-binding dye. In addition, two other methods are described capable of quantitating NET formation by measuring levels of NET-specific MPO-DNA and HNE-DNA complexes. These microplate-based methods in combination provide great tools to efficiently study the mechanism and regulation of NET formation of human neutrophils.

Colon targeted curcumin delivery using guar gum.

PubMed

Elias, Edwin J; Anil, Singhal; Ahmad, Showkat; Daud, Anwar

2010-06-01

Curcumin is used in the treatment of colon cancer, but its very poor absorption in the upper part of the GIT is a major concern. As a site for drug delivery, the colon offers a near neutral pH, reduced digestive enzymatic activity, a long transit time and an increased responsiveness to absorption enhancers. The aim of the present study was to identify a suitable polymer (guar gum) based matrix tablet for curcumin with sufficient mechanical strength and promising in vitro mouth-to-colon release profile. Three formulations of curcumin were prepared using varying concentrations of guar gum containing 50 mg curcumin by the wet granulation method. Tablets were subjected to evaluation by studying parameter like hardness, friability, drug content uniformity, and in-vitro drug release. In vitro drug release was evaluated using simulated stomach, intestinal and colonic fluids. The susceptibility of guar gum to colonic bacteria was also assessed by a drug release study with rat caecal contents. The 40% guar gum containing formulation (F-1) showed better drug release (91.1%) after 24 hours in the presence of rat caecal contents in comparison with the 50% guar gum containing formulation (F-2) (82.1%). Curcumin could, thus, be positively delivered to the colon for effective colon cancer treatment using guar gum.

Impacts of water quality on the corrosion of cast iron pipes for water distribution and proposed source water switch strategy.

PubMed

Hu, Jun; Dong, Huiyu; Xu, Qiang; Ling, Wencui; Qu, Jiuhui; Qiang, Zhimin

2018-02-01

Switch of source water may induce "red water" episodes. This study investigated the impacts of water quality on iron release, dissolved oxygen consumption (ΔDO), corrosion scale evolution and bacterial community succession in cast iron pipes used for drinking water distribution at pilot scale, and proposed a source water switch strategy accordingly. Three sets of old cast iron pipe section (named BP, SP and GP) were excavated on site and assembled in a test base, which had historically transported blended water, surface water and groundwater, respectively. Results indicate that an increasing Cl - or SO 4 2- concentration accelerated iron release, but alkalinity and calcium hardness exhibited an opposite tendency. Disinfectant shift from free chlorine to monochloramine slightly inhibited iron release, while the impact of peroxymonosulfate depended on the source water historically transported in the test pipes. The ΔDO was highly consistent with iron release in all three pipe systems. The mass ratio of magnetite to goethite in the corrosion scales of SP was higher than those of BP and GP and kept almost unchanged over the whole operation period. Siderite and calcite formation confirmed that an increasing alkalinity and hardness inhibited iron release. Iron-reducing bacteria decreased in the BP but increased in the SP and GP; meanwhile, sulfur-oxidizing, sulfate-reducing and iron oxidizing bacteria increased in all three pipe systems. To avoid the occurrence of "red water", a source water switch strategy was proposed based on the difference between local and foreign water qualities. Copyright © 2017 Elsevier Ltd. All rights reserved.

pH responsive cross-linked polymeric matrices based on natural polymers: effect of process variables on swelling characterization and drug delivery properties.

PubMed

Naeem, Fahad; Khan, Samiullah; Jalil, Aamir; Ranjha, Nazar Muhammad; Riaz, Amina; Haider, Malik Salman; Sarwar, Shoaib; Saher, Fareha; Afzal, Samrin

2017-01-01

Introduction: The current work was aimed to design and synthesize novel crosslinked pH-sensitive gelatin/pectin (Ge/Pec) hydrogels using different polymeric ratios and to explore the effect of polymers and degree of crosslinking on dynamic, equilibrium swelling and in vitro release behavior of the model drug (Mannitol). Methods: The Ge/Pec based hydrogels were prepared using glutaraldehyde as the crosslinker. Various structural parameters that affect their release behavior were determined, including swelling study, porosity, sol-gel analysis, average molecular weight between crosslinks (Mc), volume fraction of polymer (V2,s), solvent interaction parameter (χ) and diffusion coefficient. The synthesized hydrogels were subjected to various characterization tools like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and DSC differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Results: The hydrogels show highest water uptake and release at lower pH values. The FTIR spectra showed an interaction between Ge and Pec, and the drug-loaded samples also showed the drug-related peaks, indicating proper loading of the drug. DSC and TGA studies confirmed the thermal stability of hydrogel samples, while SEM showed the porous nature of hydrogels. The drug release followed non-Fickian diffusion or anomalous mechanism. Conclusion: Aforementioned characterizations reveal the successful formation of copolymer hydrogels. The pH-sensitive swelling ability and drug release behavior suggest that the rate of polymer chain relaxation and drug diffusion from these hydrogels are comparable which also predicts their possible use for site-specific drug delivery.

pH responsive cross-linked polymeric matrices based on natural polymers: effect of process variables on swelling characterization and drug delivery properties

PubMed Central

Naeem, Fahad; Khan, Samiullah; Jalil, Aamir; Ranjha, Nazar Muhammad; Riaz, Amina; Haider, Malik Salman; Sarwar, Shoaib; Saher, Fareha; Afzal, Samrin

2017-01-01

Introduction: The current work was aimed to design and synthesize novel crosslinked pH-sensitive gelatin/pectin (Ge/Pec) hydrogels using different polymeric ratios and to explore the effect of polymers and degree of crosslinking on dynamic, equilibrium swelling and in vitro release behavior of the model drug (Mannitol). Methods: The Ge/Pec based hydrogels were prepared using glutaraldehyde as the crosslinker. Various structural parameters that affect their release behavior were determined, including swelling study, porosity, sol-gel analysis, average molecular weight between crosslinks (Mc), volume fraction of polymer (V2,s), solvent interaction parameter (χ) and diffusion coefficient. The synthesized hydrogels were subjected to various characterization tools like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and DSC differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Results:The hydrogels show highest water uptake and release at lower pH values. The FTIR spectra showed an interaction between Ge and Pec, and the drug-loaded samples also showed the drug-related peaks, indicating proper loading of the drug. DSC and TGA studies confirmed the thermal stability of hydrogel samples, while SEM showed the porous nature of hydrogels. The drug release followed non-Fickian diffusion or anomalous mechanism. Conclusion: Aforementioned characterizations reveal the successful formation of copolymer hydrogels. The pH-sensitive swelling ability and drug release behavior suggest that the rate of polymer chain relaxation and drug diffusion from these hydrogels are comparable which also predicts their possible use for site-specific drug delivery. PMID:29159145

Pannexin 1 channels mediate 'find-me' signal release and membrane permeability during apoptosis.

PubMed

Chekeni, Faraaz B; Elliott, Michael R; Sandilos, Joanna K; Walk, Scott F; Kinchen, Jason M; Lazarowski, Eduardo R; Armstrong, Allison J; Penuela, Silvia; Laird, Dale W; Salvesen, Guy S; Isakson, Brant E; Bayliss, Douglas A; Ravichandran, Kodi S

2010-10-14

Apoptotic cells release 'find-me' signals at the earliest stages of death to recruit phagocytes. The nucleotides ATP and UTP represent one class of find-me signals, but their mechanism of release is not known. Here, we identify the plasma membrane channel pannexin 1 (PANX1) as a mediator of find-me signal/nucleotide release from apoptotic cells. Pharmacological inhibition and siRNA-mediated knockdown of PANX1 led to decreased nucleotide release and monocyte recruitment by apoptotic cells. Conversely, PANX1 overexpression enhanced nucleotide release from apoptotic cells and phagocyte recruitment. Patch-clamp recordings showed that PANX1 was basally inactive, and that induction of PANX1 currents occurred only during apoptosis. Mechanistically, PANX1 itself was a target of effector caspases (caspases 3 and 7), and a specific caspase-cleavage site within PANX1 was essential for PANX1 function during apoptosis. Expression of truncated PANX1 (at the putative caspase cleavage site) resulted in a constitutively open channel. PANX1 was also important for the 'selective' plasma membrane permeability of early apoptotic cells to specific dyes. Collectively, these data identify PANX1 as a plasma membrane channel mediating the regulated release of find-me signals and selective plasma membrane permeability during apoptosis, and a new mechanism of PANX1 activation by caspases.

Response to Crop-Tree Release: Sugar Maple, Red Oak, Black Cherry, and Yellow-Poplar Saplings in a 9-Year-Old Stand

Treesearch

Neil I. Lamson; H. Clay Smith

1978-01-01

Crop trees were released in an Appalachian hardwood stand (site index 70 for northern red oak) that had been clearcut 9 years earlier. We released 134 yellow-poplar, red oak, black cherry, and sugar maple stems of seedling origin to a 5-foot radius around the bole of each study tree; 140 comparable stems were not released. These trees were dominant, codominant, or...

Ciprofloxacin release using natural rubber latex membranes as carrier.

PubMed

Dias Murbach, Heitor; Jaques Ogawa, Guilherme; Azevedo Borges, Felipe; Romeiro Miranda, Matheus Carlos; Lopes, Rute; Roberto de Barros, Natan; Guedes Mazalli, Alexandre Vinicius; Gonçalves da Silva, Rosângela; Ferreira Cinman, José Luiz; de Camargo Drago, Bruno; Donizetti Herculano, Rondinelli

2014-01-01

Natural rubber latex (NRL) from Hevea brasiliensis is easily manipulated, low cost, is of can stimulate natural angiogenesis and cellular adhesion, is a biocompatible, material and presents high mechanical resistance. Ciprofloxacin (CIP) is a synthetic antibiotic (fluoroquinolone) used in the treatment of infection at external fixation screws sites and remote infections, and this use is increasingly frequent in medical practice. The aim of this study was to develop a novel sustained delivery system for CIP based on NRL membranes and to study its delivery system behavior. CIP was found to be adsorbed on the NRL membrane, according to results of energy dispersive X-ray spectroscopy. Results show that the membrane can release CIP for up to 59.08% in 312 hours and the mechanism is due to super case II (non-Fickian). The kinetics of the drug release could be fitted with double exponential function X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy shows some interaction by hydrogen bound, which influences its mechanical behavior.

Polydopamine-functionalized nanographene oxide: a versatile nanocarrier for chemotherapy and photothermal therapy

NASA Astrophysics Data System (ADS)

Zhang, Xinyuan; Nan, Xu; Shi, Wei; Sun, Yanan; Su, Huiling; He, Yuan; Liu, Xin; Zhang, Zhong; Ge, Dongtao

2017-07-01

For releasing both drug and heat to selected sites, a combination of chemotherapy and photothermal therapy in one system is a more effective way to destroy cancer cells than monotherapy. Graphene oxide (GO) with high drug-loading efficiency and near-infrared (NIR) absorbance has great potential in drug delivery and photothermal therapy, but it is difficult to load drugs with high solubility. Herein, we develop a versatile drug delivery nanoplatform based on GO for integrated chemotherapy and photothermal therapy by a facile method of simultaneous reduction and surface functionalization of GO with poly(dopamine) (PDA). Due to the excellent adhesion of PDA, both low and high solubility drugs can be encapsulated in the PDA-functionalized GO nanocomposite (rGO-PDA). The fabricated nanocomposite exhibits good biocompatibility, excellent photothermal performance, high drug loading capacity, an outstanding sustained release property, and efficient endocytosis. Moreover, NIR laser irradiation facilitates the release of loaded drugs from rGO-PDA. These features make the rGO-PDA nanocomposite achieve excellent in vivo synergistic antitumor therapeutic efficacy.

1988 environmental monitoring report, Sandia National Laboratories, Albuquerque, New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Millard, G.; Yeager, G.; Phelan, J.

1989-05-01

Sandia National Laboratories (SNL), Albuquerque is located south of Albuquerque on Kirtland Air Force Base. Because radionuclides are potentially released in small quantities from its research activities, SNL, Albuquerque has a continuing environmental monitoring program which analyzes for cesium-137, tritium, uranium, alpha emitters, and beta emitters in water, soil, air, and vegetation. A total of 5.23 curies of argon-41 were released as a result of SNL, Albuquerque operations in 1988. The albuquerque population received an estimated 0.04 person-rem from airborne radioactive releases, whereas it received greater than 44,500 person-rem from naturally occurring radionuclides. A nonradioactive effluent monitoring program at SNL,more » Albuquerque includes groundwater, stormwater and sewage monitoring. Results indicate that the groundwater has not been impacted by the chemical waste landfill. Preliminary testing of stormwater showed that no pollutants were above minimum detectable levels. A program to investigate potential remedial action sites has been started. 47 refs., 12 figs., 19 tabs.« less

Osmotically regulated floating asymmetric membrane capsule for controlled site-specific delivery of ranitidine hydrochloride: optimization by central composite design.

PubMed

Chauhan, Manvendra S; Kumar, Anil; Pathak, Kamla

2012-12-01

A nondisintegrating, floating asymmetric membrane capsule (FAMC) was developed to achieve site-specific osmotic flow of a highly water-soluble drug, ranitidine hydrochloride (RHCl), in a controlled manner. Solubility suppression of RHCl was achieved by the common ion effect, using optimized coated sodium chloride as a formulation component. The capsular wall of FAMC was prepared by the phase inversion process wherein the polymeric membrane was precipitated on glass pins by dipping them in a solution of cellulose acetate followed by quenching. Central composite design was utilized to investigate the influence of independent variables, namely, level(s) of membrane former, pore former, and osmogen, on percent cumulative drug release (response). The release mechanism of RHCl through FAMC was confirmed as osmotic pumping. The asymmetry of the membrane was characterized by scanning electron microscopy that revealed a dense nonporous outer region of membrane supported by an inner porous region. Differential scanning calorimetry indicated no incompatibility between the drug and excipients. In vitro drug release in three biorelevant media, pH 2.5 (low fed), pH 4.5 (intermediate fed), and pH 6.5 (high fed), demonstrated pH-independent release of RHCl (P > 0.05). Floating ability for 12 h of the optimized FAMC9 was visually examined during the in vitro release studies that showed maximal drug release with zero-order kinetics (r (2) = 0.9991). Thus, a novel osmotically regulated floating capsular system was developed for site-specific delivery of RHCl.

A highly efficient dual-diazonium reagent for protein crosslinking and construction of a virus-based gel.

PubMed

Ma, Dejun; Zhang, Jie; Zhang, Changyu; Men, Yuwen; Sun, Hongyan; Li, Lu-Yuan; Yi, Long; Xi, Zhen

2018-05-09

A new bench-stable reagent with double diazonium sites was designed and synthesized for protein crosslinking. Based on the highly efficient diazonium-Tyr coupling reaction, a direct mixture of the reagent and tobacco mosaic virus led to the formation of a new hydrogel, which could be degraded by chemicals and could be used to encapsulate small molecules for sustained release. Because plant viruses exhibit many chemical characteristics like protein labelling and nucleic acid packaging, the virus-based hydrogel will have large chemical space for further functionalization. Besides, this dual-diazonium reagent should be a generally useful crosslinker for chemical biology and biomaterials.

"Smart tattoo" glucose biosensors and effect of coencapsulated anti-inflammatory agents.

PubMed

Srivastava, Rohit; Jayant, Rahul Dev; Chaudhary, Ayesha; McShane, Michael J

2011-01-01

Minimally invasive glucose biosensors with increased functional longevity form one of the most promising techniques for continuous glucose monitoring. In the present study, we developed a novel nanoengineered microsphere formulation comprising alginate microsphere glucose sensors and anti-inflammatory-drug-loaded alginate microspheres. The formulation was prepared and characterized for size, shape, in vitro drug release, biocompatibility, and in vivo acceptability. Glucose oxidase (GOx)- and Apo-GOx-based glucose sensors were prepared and characterized. Sensing was performed both in distilled water and simulated interstitial body fluid. Layer-by-layer self-assembly techniques were used for preventing drug and sensing chemistry release. Finally, in vivo studies, involving histopathologic examination of subcutaneous tissue surrounding the implanted sensors using Sprague-Dawley rats, were performed to test the suppression of inflammation and fibrosis associated with glucose sensor implantation. The drug formulation showed 100% drug release with in 30 days with zero-order release kinetics. The GOx-based sensors showed good enzyme retention and enzyme activity over a period of 1 month. Apo-GOx-based visible and near-infrared sensors showed good sensitivity and analytical response range of 0-50 mM glucose, with linear range up to 12 mM glucose concentration. In vitro cell line studies proved biocompatibility of the material used. Finally, both anti-inflammatory drugs were successful in controlling the implant-tissue interface by suppressing inflammation at the implant site. The incorporation of anti-inflammatory drug with glucose biosensors shows promise in improving sensor biocompatibility, thereby suggesting potential application of alginate microspheres as "smart tattoo" glucose sensors with increased functional longevity. © 2010 Diabetes Technology Society.

Assessment of a Hydroxyapatite Permeable Reactive Barrier to Remediate Uranium at the Old Rifle Site Colorado.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Robert C.; Szecsody, James; Rigali, Mark J.

We have performed an initial evaluation and testing program to assess the effectiveness of a hydroxyapatite (Ca10(PO4)6(OH)2) permeable reactive barrier and source area treatment to decrease uranium mobility at the Department of Energy (DOE) former Old Rifle uranium mill processing site in Rifle, western Colorado. Uranium ore was processed at the site from the 1940s to the 1970s. The mill facilities at the site as well as the uranium mill tailings previously stored there have all been removed. Groundwater in the alluvial aquifer beneath the site still contains elevated concentrations of uranium, and is currently used for field tests tomore » study uranium behavior in groundwater and investigate potential uranium remediation technologies. The technology investigated in this work is based on in situ formation of apatite in sediment to create a subsurface apatite PRB and also for source area treatment. The process is based on injecting a solution containing calcium citrate and sodium into the subsurface for constructing the PRB within the uranium plume. As the indigenous sediment micro-organisms biodegrade the injected citrate, the calcium is released and reacts with the phosphate to form hydroxyapatite (precipitate). This paper reports on proof-of-principle column tests with Old Rifle sediment and synthetic groundwater.« less

Groundwater similarity across a watershed derived from time-warped and flow-corrected time series

NASA Astrophysics Data System (ADS)

Rinderer, M.; McGlynn, B. L.; van Meerveld, H. J.

2017-05-01

Information about catchment-scale groundwater dynamics is necessary to understand how catchments store and release water and why water quantity and quality varies in streams. However, groundwater level monitoring is often restricted to a limited number of sites. Knowledge of the factors that determine similarity between monitoring sites can be used to predict catchment-scale groundwater storage and connectivity of different runoff source areas. We used distance-based and correlation-based similarity measures to quantify the spatial and temporal differences in shallow groundwater similarity for 51 monitoring sites in a Swiss prealpine catchment. The 41 months long time series were preprocessed using Dynamic Time-Warping and a Flow-corrected Time Transformation to account for small timing differences and bias toward low-flow periods. The mean distance-based groundwater similarity was correlated to topographic indices, such as upslope contributing area, topographic wetness index, and local slope. Correlation-based similarity was less related to landscape position but instead revealed differences between seasons. Analysis of variance and partial Mantel tests showed that landscape position, represented by the topographic wetness index, explained 52% of the variability in mean distance-based groundwater similarity, while spatial distance, represented by the Euclidean distance, explained only 5%. The variability in distance-based similarity and correlation-based similarity between groundwater and streamflow time series was significantly larger for midslope locations than for other landscape positions. This suggests that groundwater dynamics at these midslope sites, which are important to understand runoff source areas and hydrological connectivity at the catchment scale, are most difficult to predict.

Herbicide treatments of Japanese honeysuckle for releasing desirable reproduction or for site preparation

Treesearch

Silas Little; Horace A. Somes

1968-01-01

Various herbicides were used to release pine or hardwood seedlings from competition of Japanese honeysuckle, or to eliminate honeysuckle in areas being prepared for regeneration. Considering both the degree of honeysuckle control and the amount of damage to desired trees, we recommend 2,4-D emulsifiable acid with application in late fall for release of hardwoods and in...

Synaptic ribbon. Conveyor belt or safety belt?

PubMed

Parsons, T D; Sterling, P

2003-02-06

The synaptic ribbon in neurons that release transmitter via graded potentials has been considered as a conveyor belt that actively moves vesicles toward their release sites. But evidence has accumulated to the contrary, and it now seems plausible that the ribbon serves instead as a safety belt to tether vesicles stably in mutual contact and thus facilitate multivesicular release by compound exocytosis.

A mark-release-recapture experiment with Anopheles sinensis in the northern part of Gyeonggi-do, Korea.

PubMed

Cho, Shin-Hyeong; Lee, Hyeong-Woo; Shin, E-Hyun; Lee, Hee-Il; Lee, Wook-Gyo; Kim, Chong-Han; Kim, Jong-Taek; Lee, Jong-Soo; Lee, Won-Ja; Jung, Gi-Gon; Kim, Tong-Soo

2002-09-01

In order to study the range of flight and feeding activity of Anopheles sinensis, the dispersal experiment was conducted in Paju city, located in the northern part of Gyeonggi-do, Republic of Korea, during the period of 7th to 28th September 1998. Unfed females An. sinensis were collected in cowshed and released after being marked with fluorescent dye at 23:00 hours on the same day. Released female mosquitoes were recaptured everyday during 21 days using light traps, which were set at 10 sites in the cowsheds located 1, 3, 6, 9 and 12 km north-northwest and north-northeast and at 3 sites located 1, 6 and 9 km toward south-west from the release point. In addition, to study the longest flight distance in one night, we set the light traps at 16 and 20 km toward north-northeast from the release site. All the collected mosquitoes were placed on filter papers and observed on UV transilluminator after treatment with one drop of 100% ethanol. Out of 12,773 females of An. sinensis released, 194 marked females mosquitoes were recaptured, giving 1.52% recapture rate. Of 194, 72 mosquitoes (37.1%) were recaptured in light traps from three places set at 1 km from the release point, 57 mosquitoes (29.4%) from two places at 1-3 km, 41 mosquitoes (21.1%) from three places at 3-6 km, 20 mosquitoes (10.3%) from three places at 6-9 km, and 4 mosquitoes (2.1%) from two places at 9-12 km. Since 170 female mosquitoes (87.6%) out of 194 marked mosquitoes were captured within 6 km from the release point, this flight radius represents the main activity area. An sinensis was found to be able to fly at least 12 km during one night.

Effects of the rate of releases from Sam Rayburn Reservoir on the Aeration Capacity of the Angelina River, eastern Texas

USGS Publications Warehouse

Rawson, Jack; Goss, Richard L.; Rathbun, Ira G.

1980-01-01

A three-phase study was conducted during July and August 1979 to determine the effects of varying release rates through the power-outlet works at Sam Rayburn Reservoir, eastern Texas, on aeration capacity of a 14-mile reach of the Angelina River below Sam Rayburn Dam. The dominant factors that affected the aeration capacity during the study time were time of travel and the dissolved-oxygen deficit of the releases. Aeration was low throughout the study but increased in response to increases in the dissolved-oxygen deficit and the duration of time that the releases were exposed to the atmosphere (time of travel). The average concentration of dissolved oxygen sustained by release of 8,800 cubic feet per second decreased from 5.0 milligrams per liter at a site near the power outlet to 4.8 milligrams per liter at a site about 14 miles downstream; the time of travel averaged about 8 hours. The average concentration of dissolved oxygen in flow sustained by releases of 2,200 cubic feet per second increased from 5.2 to 5.5 milligrams per liter; the time of travel averaged about 20 hours. (USGS)

Petroleum Release Assessment and Impacts of Weather Extremes

EPA Science Inventory

Contaminated ground water and vapor intrusion are two major exposure pathways of concern at petroleum release sites. EPA has recently developed a model for petroleum vapor intrusion, called PVIScreen, which incorporates variability and uncertainty in input parameters. This ap...

Report: Gold King Mine Release - Inspector General Response to Congressional Requests

EPA Pesticide Factsheets

Report #17-P-0250, June 12, 2017. Since causing the uncontrolled release of 3 million gallons of contaminated mine water, the EPA has taken steps to minimize the possibility of similar incidents at other mine sites.

HPMA-based block copolymers promote differential drug delivery kinetics for hydrophobic and amphiphilic molecules.

PubMed

Tomcin, Stephanie; Kelsch, Annette; Staff, Roland H; Landfester, Katharina; Zentel, Rudolf; Mailänder, Volker

2016-04-15

We describe a method how polymeric nanoparticles stabilized with (2-hydroxypropyl)methacrylamide (HPMA)-based block copolymers are used as drug delivery systems for a fast release of hydrophobic and a controlled release of an amphiphilic molecule. The versatile method of the miniemulsion solvent-evaporation technique was used to prepare polystyrene (PS) as well as poly-d/l-lactide (PDLLA) nanoparticles. Covalently bound or physically adsorbed fluorescent dyes labeled the particles' core and their block copolymer corona. Confocal laser scanning microscopy (CLSM) in combination with flow cytometry measurements were applied to demonstrate the burst release of a fluorescent hydrophobic drug model without the necessity of nanoparticle uptake. In addition, CLSM studies and quantitative calculations using the image processing program Volocity® show the intracellular detachment of the amphiphilic block copolymer from the particles' core after uptake. Our findings offer the possibility to combine the advantages of a fast release for hydrophobic and a controlled release for an amphiphilic molecule therefore pointing to the possibility to a 'multi-step and multi-site' targeting by one nanocarrier. We describe thoroughly how different components of a nanocarrier end up in cells. This enables different cargos of a nanocarrier having a consecutive release and delivery of distinct components. Most interestingly we demonstrate individual kinetics of distinct components of such a system: first the release of a fluorescent hydrophobic drug model at contact with the cell membrane without the necessity of nanoparticle uptake. Secondly, the intracellular detachment of the amphiphilic block copolymer from the particles' core after uptake occurs. This offers the possibility to combine the advantages of a fast release for a hydrophobic substance at the time of interaction of the nanoparticle with the cell surface and a controlled release for an amphiphilic molecule later on therefore pointing to the possibility to a 'multi-step and multisite' targeting by one nanocarrier. We therefore feel that this could be used for many cellular systems where the combined and orchestrated delivery of components is prerequisite in order to obtain the highest efficiency. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Endocrine and physiological changes in Atlantic salmon smolts following hatchery release

USGS Publications Warehouse

McCormick, S.D.; O'Dea, M. F.; Moeckel, Amy M.; Bjornsson, Bjorn Thrandur

2003-01-01

Physiological and endocrine changes during smolt development were examined in Atlantic salmon (Salmo salar) reared and released as part of a restoration program on the Connecticut River and its tributaries. Fish were reared in a cold water hatchery in Pittsford, VT and released into the Farmington River, CT (a major tributary of the Connecticut River) or into 'imprint ponds' fed by the Farmington River. Smelts were recaptured 10-20 days after their release at a smolt bypass facility 16 km downstream of their release site. Fish sampled at the hatchery from January to May had only moderate smolt development based on salinity tolerance, gill Na+,K+-ATPase activity and hormone profiles. In contrast, smolts released into the river or imprint ponds had higher salinity tolerance, gill Na+,K+-ATPase activity, plasma growth hormone, insulin-like growth factor I (IGF-I) and thyroxine than smolts that remained in the hatchery. These physiological and endocrine changes were nearly identical to those of smolts that had been released into the river 2 years earlier as fry and were captured as active migrants at the same bypass facility (stream-reared smolts). The stomach contents as a percent of body weight (primarily aquatic insects) varied greatly among individuals and were greater in hatchery-reared fish than stream-reared smolts. Results from the rearing of hatchery fish at temperatures similar to that of the Farmington River indicate that some of the physiological changes may be due to increased temperature after release, though other factors may also be involved. The results indicate that substantial physiological smolt development can occur after hatchery release, coincident with downstream migration. ?? 2003 Published by Elsevier Science B.V.

Olfaction and the homing ability of pigeons raised in a tropical area in Brazil.

PubMed

Benvenuti, Silvano; Ranvaud, Ronald

2004-12-01

Several workers have investigated the effect of anosmia on pigeon navigation in different geographical locations because it has been suggested that homing behavior is based on different cues, such as olfactory cues, the Earth's magnetic field or infrasound, and that in the absence of one cue another would be used. In this situation, no cue is universally indispensable, including olfactory ones. In order to extend such observations to a novel biome, we observed the behaviour of 192 young inexperienced birds raised in southeastern Brazil, a tropical area where olfactory tests had never been run before. The birds were released from eight symmetrically distributed sites 17 to 44 km from the loft. Half of these birds (experimentals) had been made temporarily anosmic by washing their olfactory mucosae with 4% solution of ZnSO4 the day before release, while controls were treated with Ringer solution. The results of release tests showed that anosmia totally impaired the navigational performance of experimental birds, which were unable to home from sites at relatively short distances from home (34-44 km) and whose pooled initial bearings produced a (negative) homeward component not significantly different from 0. Homing performance of controls was significantly better, and their pooled vanishing bearings had a significant homeward component, in spite of much scatter in individual releases. We conclude that pigeon homing in the study area depends on olfactory information, even though local environmental conditions in the interior of the State of Sao Paulo, as in several other parts of the world, do not appear to be as favorable as Italy for the development of efficient olfactory navigation.

The role of transmembrane segment 5 (TM5) in Na2 release and the conformational transition of neurotransmitter:sodium symporters toward the inward-open state

PubMed Central

Stolzenberg, Sebastian; Li, Zheng; Quick, Matthias; Malinauskaite, Lina; Nissen, Poul; Weinstein, Harel; Javitch, Jonathan A.; Shi, Lei

2017-01-01

Neurotransmitter:sodium symporters (NSSs) terminate neurotransmission by the reuptake of released neurotransmitters. This active accumulation of substrate against its concentration gradient is driven by the transmembrane Na+ gradient and requires that the transporter traverses several conformational states. LeuT, a prokaryotic NSS homolog, has been crystallized in outward-open, outward-occluded, and inward-open states. Two crystal structures of another prokaryotic NSS homolog, the multihydrophobic amino acid transporter (MhsT) from Bacillus halodurans, have been resolved in novel inward-occluded states, with the extracellular vestibule closed and the intracellular portion of transmembrane segment 5 (TM5i) in either an unwound or a helical conformation. We have investigated the potential involvement of TM5i in binding and unbinding of Na2, i.e. the Na+ bound in the Na2 site, by carrying out comparative molecular dynamics simulations of the models derived from the two MhsT structures. We find that the helical TM5i conformation is associated with a higher propensity for Na2 release, which leads to the repositioning of the N terminus and transition to an inward-open state. By using comparative interaction network analysis, we also identify allosteric pathways connecting TM5i and the Na2 binding site to the extracellular and intracellular regions. Based on our combined computational and mutagenesis studies of MhsT and LeuT, we propose that TM5i plays a key role in Na2 binding and release associated with the conformational transition toward the inward-open state, a role that is likely to be shared across the NSS family. PMID:28320858

Research on the Management of Contaminated Sites

EPA Pesticide Factsheets

EPA is working to provide solutions and restore sites whose soils or sediments are contaminated by environmental releases of chemicals and toxins, and protect ecosystems and public health from harmful exposure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

James P. Barry; Peter G. Brewer

OAK-B135 This report summarizes activities and results of investigations of the potential environmental consequences of direct injection of carbon dioxide into the deep-sea as a carbon sequestration method. Results of field experiments using small scale in situ releases of liquid CO2 are described in detail. The major conclusions of these experiments are that mortality rates of deep sea biota will vary depending on the concentrations of CO2 in deep ocean waters that result from a carbon sequestration project. Large changes in seawater acidity and carbon dioxide content near CO2 release sites will likely cause significant harm to deep-sea marine life.more » Smaller changes in seawater chemistry at greater distances from release sites will be less harmful, but may result in significant ecosystem changes.« less

Geochemical and mineralogical study of a site severely polluted with heavy metals (Maatheide, Lommel, Belgium)

NASA Astrophysics Data System (ADS)

Horckmans, L.; Swennen, R.; Deckers, J.

2006-07-01

The former zinc smelter site ‘de Maatheide’ in Lommel (Belgium) was severely polluted with heavy metals and the pollution spread into the surroundings by rain water leaching and wind transportation. This study focuses on the processes of immobilization and natural attenuation that took place on the site. Three important factors were found. Firstly, the high pH values (pH 7-8) in the topsoil influence the mobility of heavy metals. Secondly, the spodic horizons below the polluted top layer seem to accumulate heavy metals, thereby slowing down their release into the environment. Finally, the glassy phases and iron oxi/hydroxides that are present can encapsulate heavy metals during their formation/recrystallization, thereby immobilizing them. An additional shielding effect results from the reaction rims of goethite around the contaminant phases, which partially inhibit the weathering process and release of contaminants. This shielding effect is an important factor to take into account when modelling contaminant release.

Design of multimodal degradable hydrogels for controlled therapeutic delivery

NASA Astrophysics Data System (ADS)

Kharkar, Prathamesh Madhav

Hydrogels are of growing interest for the delivery of therapeutics to specific sites in the body. For localized drug delivery, hydrophilic polymeric precursors often are laden with bioactive moieties and then directly injected to the site of interest for in situ gel formation. The release of physically entrapped cargo is dictated by Fickian diffusion, degradation of the drug carrier, or a combination of both. The goal of this work was to design and characterize degradable hydrogel formulations that are responsive to multiple biologically relevant stimuli for degradation-mediated delivery of cargo molecules such as therapeutic proteins, growth factors, and immunomodulatory agents. We began by demonstrating the use of cleavable click linkages formed by Michael-type addition reactions in conjunction with hydrolytically cleavable functionalities for the degradation of injectable hydrogels by endogenous stimuli for controlled protein release. Specifically, the reaction between maleimides and thiols was utilized for hydrogel formation, where thiol selection dictates the degradability of the resulting linkage under thiol-rich reducing conditions. Relevant microenvironments where degradation would occur in vivo include those rich in glutathione (GSH), a tripeptide that is found at elevated concentrations in carcinoma tissues. Degradation of the hydrogels was monitored with rheometry and volumetric swelling measurements. Arylthiol-based thioether succinimide linkages underwent degradation via click cleavage and thiol exchange reaction in the presence of GSH and via ester hydrolysis, whereas alkylthiol-based thioether succinimide linkages only undergo degradation by only ester hydrolysis. The resulting control over the degradation rate within a reducing microenvironment resulted in 2.5 fold differences in the release profile of the model protein, a fluorescently-labeled bovine serum albumin, from dually degradable hydrogels compared to non-degradable hydrogels, where the thiol exchange reaction facilitated rapid and responsive protein release in the presence of GSH. A photolabile o-nitrobenzyl ether group (o-NB) was subsequently incorporated within the PEG-based, gel-forming monomers to demonstrate cargo release triggered by exogenous stimuli for patient-specific therapies. Upon the application of cytocompatible doses of light, the photolabile o-NB linkage underwent irreversible cleavage yielding ketone and carboxylic acid-based cleavage products. Hydrogel degradation kinetics was characterized in response to externally applied cytocompatible light or GSH in aqueous microenvironments. By incorporating a photodegradable o-nitrobenzyl ether group, a thiol-sensitive succinimide thioether linkage, and ester linkages within the hydrogels, we demonstrated unique control over degradation via surface erosion or bulk degradation mechanisms, respectively, with degradation rate constants ranging from 10-1 min-1 to 10-4 min-1. As a proof of concept, the controlled release of nanobeads from the hydrogel was demonstrated in a preprogrammed and stimuli-responsive fashion. The multimodal degradable hydrogels were then investigated for the local controlled release of small molecular weight proteins, which are of interest for regulating various cellular functions and fates in vivo. Low molecular weight heparin, a highly sulfated polysaccharide was incorporated within the hydrogel network by Michael-type reaction due to its affinity with biologics such as growth factors and immunomodulatory proteins. Incorporation of reduction-sensitive linkages resulted in 2.3 fold differences in the release profile of fibroblast growth factor-2 (FGF-2) in the presence of GSH compared to non-reducing microenvironment. Bioactivity of released FGF-2 was comparable to pristine FGF-2, indicating the ability of the hydrogel to retain bioactivity of cargo molecules during encapsulation and release. Further, preliminary in vivo studies demonstrated control over hydrogel degradation by varying % degradable contents. Collectively, this research developed injectable hydrogels that are responsive to various endogenous and exogenous stimuli, establishing a platform for stimuli-responsive drug delivery carriers.

Preliminary results from the lunar prospector alpha particle spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawson, S. L.

2001-01-01

The Lunar Prospector Alpha Particle Spectrometer (LP APS) builds on Apollo heritage and maps the distribution of outgassing sites on the Moon. The APS searches for lunar surface gas release events and maps their distribution by detecting alpha particles produced by the decay of gaseous radon-222 (5.5 MeV, 3.8 day half-life) and solid polonium-210 (5.3 MeV, 138 day half-life, but remains on the surface with a 21 year half-life as lead-210), which are radioactive daughters from the decay of uranium-238. Radon is in such small quantities that it is not released directly from the lunar interior, rather it is entrainedmore » in a stream of gases and serves as a tracer for such gases. Once released, the radon spreads out by 'bouncing' across the surface on ballistic trajectories in a random-walk process. The 3.8 day half-life of radon-222 allows the gas to spread out by several 100 km before it decays and allows the APS to detect gas release events up to a few days after they occur. The long residence time (10s of years) of the lead-210 precursor to the polonium-210 allows the mapping of gas vents which have been active over the last approximately 50 years. Because radon and polonium are daughter products of the decay of uranium, the background level of alpha particle activity is a function of the lunar crustal uranium distribution. Using radioactive radon and polonium as tracers, the Apollo 15 and 16 Command Module orbital alpha particle experiments obtained evidence for the release of gases at several sites beneath the orbit tracks, especially over the Aristarchus Plateau and Mare Fecunditatis [1]. Aristarchus crater had previously been identified by ground-based observers as the site of transient optical events [2]. The Apollo 17 surface mass spectrometer showed that argon-40 is released from the lunar interior every few months, apparently in concert with some of the shallow moonquakes that are believed to be of tectonic origin [3]. The latter tectonic events could be associated with very young scarps identified in the lunar highlands [4] and are believed to indicate continued global contraction. Such quakes could open fissures leading to the release of gases that are trapped below the surface. The detection of radon-222 outgassing events at the margins of Fecunditatis basin was surprising because the observed surface distribution of uranium and thorium do not extend sufficiently eastward to cover Fecunditatis. If the Apollo detections prove sound, then those alpha particle emissions indicate substantial subsurface concentrations of uranium-238 within Fecunditatis. A primary goal of the APS was to map gas-release events, thus allowing both an appraisal of the current level of tectonic activity on the Moon and providing a probe of subsurface uranium concentrations.« less

Effects and quantification of acid runoff from sulfide-bearing rock deposited during construction of Highway E18, Norway

USGS Publications Warehouse

Hindar, Atle; Nordstrom, D. Kirk

2015-01-01

The Highway E18 between the cities of Grimstad and Kristiansand, southern Norway, constructed in the period 2006–2009, cuts through sulfide-bearing rock. The geology of this area is dominated by slowly-weathering gneiss and granites, and oxidation of fresh rock surfaces can result in acidification of surface water. Sulfide-containing rock waste from excavations during construction work was therefore deposited in three waste rock deposits off-site. The deposits consist of 630,000–2,360,000 metric tons of waste rock material. Shell sand and limestone gravel were added in layers in adequate amounts to mitigate initial acid runoff in one of the deposits. The shell sand addition was not adequate in the two others. The pH in the effluents from these two was reduced from 4.9–6.5 to 4.0–4.6, and Al concentrations increased from below 0.4 mg/L to 10–20 mg/L. Stream concentrations of trace metals increased by a factor of 25–400, highest for Ni, and then in decreasing order for Co, Mn, Cd, Zn and Cu. Concentrations of As, Cr and Fe remained unchanged. Ratios of Co/Ni and Cd/Zn indicate that the metal sources for these pair of metals are sphalerite and pyrite, respectively. Based on surveys and established critical limits for Al, surface waters downstream became toxic to fish and invertebrates. The sulfur release rates were remarkably stable in the monitoring period at all three sites. Annual sulfur release was 0.1–0.4% of the total amount of sulfur in the deposit, indicating release periods of 250–800 years. Precipitates of Al-hydroxysulfates, well-known from mining sites, were found at the base of the deposits, in streams and also along the ocean shore-line. The effects of added neutralization agents in the deposits and in treatment areas downstream gradually decreased, as indicated by reduced stream pH over time. Active measures are needed to avoid harmful ecological effects in the future.

Radioiodine in the Savannah River Site environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kantelo, M.V.; Bauer, L.R.; Marter, W.L.

1993-01-15

Radioiodine, which is the collective term for all radioactive isotopes of the element iodine, is formed at the Savannah River Site (SRS) principally as a by-product of nuclear reactor operations. Part of the radioiodine is released to the environment during reactor and reprocessing operations at the site. The purpose of this report is to provide an introduction to radioiodine production and disposition, its status in the environment, and the radiation dose and health risks as a consequence of its release to the environment around the Savannah River Plant. A rigorous dose reconstruction study is to be completed by thee Centermore » for Disease Control during the 1990s.« less

Methane emissions and contaminant degradation rates at sites affected by accidental releases of denatured fuel-grade ethanol

NASA Astrophysics Data System (ADS)

Sihota, Natasha J.; Mayer, K. Ulrich; Toso, Mark A.; Atwater, Joel F.

2013-08-01

The recent increase in the use of denatured fuel-grade ethanol (DFE) has enhanced the probability of its environmental release. Due to the highly labile nature of ethanol (EtOH), it is expected to rapidly biodegrade, increasing the potential for inducing methanogenic conditions in the subsurface. As environmental releases of DFE can be expected to occur at the ground surface or in the vadose zone (e.g., due to surficial spills from rail lines or tanker trucks and leaking underground storage tanks), the potential for methane (CH4) generation at DFE spill sites requires evaluation. An assessment is needed because high CH4 generation rates may lead to CH4 fluxes towards the ground surface, which is of particular concern if spills are located close to human habitation—related to concerns of soil vapor intrusion (SVI). This work demonstrates, for the first time, the measurement of surficial gas release rates at large volume DFE spill sites. Two study sites, near Cambria and Balaton, in MN are investigated. Total carbon emissions at the ground surface (summing carbon dioxide (CO2) and CH4 emissions) are used to quantify depth-integrated DFE degradation rates. Results from both sites demonstrate that substantial CO2 and CH4 emissions do occur—even years after a spill. However, large total carbon fluxes, and CH4 emissions in particular, were restricted to a localized area within the DFE source zone. At the Balaton site, estimates of total DFE carbon losses in the source zone ranged between 5 and 174 μmol m- 2 s- 1, and CH4 effluxes ranged between non-detect and 9 μmol m- 2 s- 1. At the Cambria site estimates of total DFE carbon losses in the source zone ranged between 8 and 500 μmol m- 2 s- 1, and CH4 effluxes ranged between non-detect and 393 μmol m- 2 s- 1. Substantial CH4 accumulation, coupled with oxygen (O2) depletion, measured in samples collected from custom-designed gas collection chambers at the Cambria site suggests that the development of explosion or asphyxiation hazards is possible in confined spaces above a rapidly degrading DFE release. However, the results also indicate that the development of such hazards is locally constrained, will require a high degree of soil moisture, close proximity to the source zone, a good connection between the soil and the confined space, and poorly aerated conditions.

Methane emissions and contaminant degradation rates at sites affected by accidental releases of denatured fuel-grade ethanol.

PubMed

Sihota, Natasha J; Mayer, K Ulrich; Toso, Mark A; Atwater, Joel F

2013-08-01

The recent increase in the use of denatured fuel-grade ethanol (DFE) has enhanced the probability of its environmental release. Due to the highly labile nature of ethanol (EtOH), it is expected to rapidly biodegrade, increasing the potential for inducing methanogenic conditions in the subsurface. As environmental releases of DFE can be expected to occur at the ground surface or in the vadose zone (e.g., due to surficial spills from rail lines or tanker trucks and leaking underground storage tanks), the potential for methane (CH4) generation at DFE spill sites requires evaluation. An assessment is needed because high CH4 generation rates may lead to CH4 fluxes towards the ground surface, which is of particular concern if spills are located close to human habitation-related to concerns of soil vapor intrusion (SVI). This work demonstrates, for the first time, the measurement of surficial gas release rates at large volume DFE spill sites. Two study sites, near Cambria and Balaton, in MN are investigated. Total carbon emissions at the ground surface (summing carbon dioxide (CO2) and CH4 emissions) are used to quantify depth-integrated DFE degradation rates. Results from both sites demonstrate that substantial CO2 and CH4 emissions do occur-even years after a spill. However, large total carbon fluxes, and CH4 emissions in particular, were restricted to a localized area within the DFE source zone. At the Balaton site, estimates of total DFE carbon losses in the source zone ranged between 5 and 174 μmol m(-2) s(-1), and CH4 effluxes ranged between non-detect and 9 μmol m(-2) s(-1). At the Cambria site estimates of total DFE carbon losses in the source zone ranged between 8 and 500 μmol m(-2) s(-1), and CH4 effluxes ranged between non-detect and 393 μmol m(-2) s(-1). Substantial CH4 accumulation, coupled with oxygen (O2) depletion, measured in samples collected from custom-designed gas collection chambers at the Cambria site suggests that the development of explosion or asphyxiation hazards is possible in confined spaces above a rapidly degrading DFE release. However, the results also indicate that the development of such hazards is locally constrained, will require a high degree of soil moisture, close proximity to the source zone, a good connection between the soil and the confined space, and poorly aerated conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

THE DNAPL REMEDIATION CHALLENGE: IS THERE A CASE FOR SOURCE DEPLETION?

EPA Science Inventory

Releases of Dense Non-Aqueous Phase Liquids (DNAPLs) at a large number of public and private sector sites in the United States pose significant challenges in site remediation and long-term site management. Extensive contamination of groundwater occurs as a result of significant ...

Strategic Siting of Contingency Bases: Assessing Options for Potable Water

DTIC Science & Technology

2017-02-01

Assessing Options for Potable Water Co ns tr uc tio n En gi ne er in g R es ea rc h La bo ra to ry Lucy A. Whalley, David A. Krooks, and...George W. Calfas February 2017 Approved for public release; distribution is unlimited. The U.S. Army Engineer Research and Development...geospatial sciences, water resources, and environmental sciences for the Army, the Department of Defense, civilian agencies, and our nation’s

Tracking solvent and protein movement during CO2 release in carbonic anhydrase II crystals

PubMed Central

Kim, Chae Un; Song, HyoJin; Avvaru, Balendu Sankara; Gruner, Sol M.; Park, SangYoun; McKenna, Robert

2016-01-01

Carbonic anhydrases are mostly zinc metalloenzymes that catalyze the reversible hydration/dehydration of CO2/HCO3−. Previously, the X-ray crystal structures of CO2-bound holo (zinc-bound) and apo (zinc-free) human carbonic anhydrase IIs (hCA IIs) were captured at high resolution. Here, we present sequential timeframe structures of holo- [T = 0 s (CO2-bound), 50 s, 3 min, 10 min, 25 min, and 1 h] and apo-hCA IIs [T = 0 s, 50 s, 3 min, and 10 min] during the “slow” release of CO2. Two active site waters, WDW (deep water) and WDW′ (this study), replace the vacated space created on CO2 release, and another water, WI (intermediate water), is seen to translocate to the proton wire position W1. In addition, on the rim of the active site pocket, a water W2′ (this study), in close proximity to residue His64 and W2, gradually exits the active site, whereas His64 concurrently rotates from pointing away (“out”) to pointing toward (“in”) active site rotameric conformation. This study provides for the first time, to our knowledge, structural “snapshots” of hCA II intermediate states during the formation of the His64-mediated proton wire that is induced as CO2 is released. Comparison of the holo- and apo-hCA II structures shows that the solvent network rearrangements require the presence of the zinc ion. PMID:27114542

ATP-Responsive and Near-Infrared-Emissive Nanocarriers for Anticancer Drug Delivery and Real-Time Imaging.

PubMed

Qian, Chenggen; Chen, Yulei; Zhu, Sha; Yu, Jicheng; Zhang, Lei; Feng, Peijian; Tang, Xin; Hu, Quanyin; Sun, Wujin; Lu, Yue; Xiao, Xuanzhong; Shen, Qun-Dong; Gu, Zhen

2016-01-01

Stimuli-responsive and imaging-guided drug delivery systems hold vast promise for enhancement of therapeutic efficacy. Here we report an adenosine-5'-triphosphate (ATP)-responsive and near-infrared (NIR)-emissive conjugated polymer-based nanocarrier for the controlled release of anticancer drugs and real-time imaging. We demonstrate that the conjugated polymeric nanocarriers functionalized with phenylboronic acid tags on surface as binding sites for ATP could be converted to the water-soluble conjugated polyelectrolytes in an ATP-rich environment, which promotes the disassembly of the drug carrier and subsequent release of the cargo. In vivo studies validate that this formulation exhibits promising capability for inhibition of tumor growth. We also evaluate the metabolism process by monitoring the fluorescence signal of the conjugated polymer through the in vivo NIR imaging.

Risk based requirements for long term stewardship: A proof-of-principle analysis of an analytic method tested on selected Hanford locations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jarvis, T.T.; Andrews, W.B.; Buck, J.W.

1998-03-01

Since 1989, the Department of Energy`s (DOE) Environmental Management (EM) Program has managed the environmental legacy of US nuclear weapons production, research and testing at 137 facilities in 31 states and one US territory. The EM program has conducted several studies on the public risks posed by contaminated sites at these facilities. In Risks and the Risk Debate [DOE, 1995a], the Department analyzed the risks at sites before, during, and after remediation work by the EM program. The results indicated that aside from a few urgent risks, most hazards present little inherent risk because physical and active site management controlsmore » limit both the releases of site contaminants, and public access to these hazards. Without these controls, these sites would pose greater risks to the public. Past risk reports, however, provided little information about post-cleanup risk, primarily because of uncertainty about future site uses and site characteristics at the end of planned cleanup activities. This is of concern because in many cases current cleanup technologies, and remedies, will last a shorter period of time than the waste itself and the resulting contamination will remain hazardous.« less

SRS: Site ranking system for hazardous chemical and radioactive waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rechard, R.P.; Chu, M.S.Y.; Brown, S.L.

1988-05-01

This report describes the rationale and presents instructions for a site ranking system (SRS). SRS ranks hazardous chemical and radioactive waste sites by scoring important and readily available factors that influence risk to human health. Using SRS, sites can be ranked for purposes of detailed site investigations. SRS evaluates the relative risk as a combination of potentially exposed population, chemical toxicity, and potential exposure of release from a waste site; hence, SRS uses the same concepts found in a detailed assessment of health risk. Basing SRS on the concepts of risk assessment tends to reduce the distortion of results foundmore » in other ranking schemes. More importantly, a clear logic helps ensure the successful application of the ranking procedure and increases its versatility when modifications are necessary for unique situations. Although one can rank sites using a detailed risk assessment, it is potentially costly because of data and resources required. SRS is an efficient approach to provide an order-of-magnitude ranking, requiring only readily available data (often only descriptive) and hand calculations. Worksheets are included to make the system easier to understand and use. 88 refs., 19 figs., 58 tabs.« less

40 CFR 372.10 - Recordkeeping.

Code of Federal Regulations, 2011 CFR

2011-07-01

... COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW General....25 applies for each toxic chemical. (iii) Documentation supporting the calculations of the quantity of each toxic chemical released to the environment or transferred to an off-site location. (iv...

40 CFR 372.10 - Recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-07-01

... COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW General....25 applies for each toxic chemical. (iii) Documentation supporting the calculations of the quantity of each toxic chemical released to the environment or transferred to an off-site location. (iv...

40 CFR 143-215.75 - Title

Code of Federal Regulations, 2010 CFR

2002-07-01

...: Acceptability of Information Section 6: Security f. Chapter 9: Severability g. Chapter 10: Effective Date.... (g) Release detection recordkeeping. Section 22a-449(d)-105 Release Reporting, Investigation, and.... (e) Initial site characterization. (f) Free product removal. (g) Investigations for soil and ground...

Neuroendokrine Regulationsmechanismen

NASA Astrophysics Data System (ADS)

Wuttke, Wolfgang

1980-06-01

The main center for the control of sexual functions is located in the hypothalamus. The medial preoptic area and the mediobasal hypothalamus are sites of production of neuropeptides which are released into the hypothalamo-pituitary portal vessel system and which function as releasing and inhibiting hormones.

Tanzania Images Highlight Improvements in Full-Resolution SRTM Africa Data

NASA Image and Video Library

2014-09-24

A site in the Crater Highlands of Tanzania reveals the difference between NASA Shuttle Radar Topography Mission SRTM digital elevation model data as originally released in 2004 left and as now released at full resolution in 2014 right.

Field evaluation of the establishment potential of wMelPop Wolbachia in Australia and Vietnam for dengue control.

PubMed

Nguyen, Tran Hien; Nguyen, H Le; Nguyen, Thu Yen; Vu, Sinh Nam; Tran, Nhu Duong; Le, T N; Vien, Quang Mai; Bui, T C; Le, Huu Tho; Kutcher, Simon; Hurst, Tim P; Duong, T T H; Jeffery, Jason A L; Darbro, Jonathan M; Kay, B H; Iturbe-Ormaetxe, Iñaki; Popovici, Jean; Montgomery, Brian L; Turley, Andrew P; Zigterman, Flora; Cook, Helen; Cook, Peter E; Johnson, Petrina H; Ryan, Peter A; Paton, Chris J; Ritchie, Scott A; Simmons, Cameron P; O'Neill, Scott L; Hoffmann, Ary A

2015-10-28

Introduced Wolbachia bacteria can influence the susceptibility of Aedes aegypti mosquitoes to arboviral infections as well as having detrimental effects on host fitness. Previous field trials demonstrated that the wMel strain of Wolbachia effectively and durably invades Ae. aegypti populations. Here we report on trials of a second strain, wMelPop-PGYP Wolbachia, in field sites in northern Australia (Machans Beach and Babinda) and central Vietnam (Tri Nguyen, Hon Mieu Island), each with contrasting natural Ae. aegypti densities. Mosquitoes were released at the adult or pupal stages for different lengths of time at the sites depending on changes in Wolbachia frequency as assessed through PCR assays of material collected through Biogents-Sentinel (BG-S) traps and ovitraps. Adult numbers were also monitored through BG-S traps. Changes in Wolbachia frequency were compared across hamlets or house blocks. Releases of adult wMelPop-Ae. aegypti resulted in the transient invasion of wMelPop in all three field sites. Invasion at the Australian sites was heterogeneous, reflecting a slower rate of invasion in locations where background mosquito numbers were high. In contrast, invasion across Tri Nguyen was relatively uniform. After cessation of releases, the frequency of wMelPop declined in all sites, most rapidly in Babinda and Tri Nguyen. Within Machans Beach the rate of decrease varied among areas, and wMelPop was detected for several months in an area with a relatively low mosquito density. These findings highlight challenges associated with releasing Wolbachia-Ae. aegypti combinations with low fitness, albeit strong virus interference properties, as a means of sustainable control of dengue virus transmission.

Half-of-the-sites reactivity of outer-membrane phospholipase A against an active-site-directed inhibitor.

PubMed

Ubarretxena-Belandia, I; Cox, R C; Dijkman, R; Egmond, M R; Verheij, H M; Dekker, N

1999-03-01

The reaction of a novel active-site-directed phospholipase A1 inhibitor with the outer-membrane phospholipase A (OMPLA) was investigated. The inhibitor 1-p-nitrophenyl-octylphosphonate-2-tridecylcarbamoyl-3-et hanesulfonyl -amino-3-deoxy-sn-glycerol irreversibly inactivated OMPLA. The inhibition reaction did not require the cofactor calcium or an unprotonated active-site His142. The inhibition of the enzyme solubilized in hexadecylphosphocholine micelles was characterized by a rapid (t1/2 = 20 min) and complete loss of enzymatic activity, concurrent with the covalent modification of 50% of the active-site serines, as judged from the amount of p-nitrophenolate (PNP) released. Modification of the remaining 50% occurred at a much lower rate, indicative of half-of-the-sites reactivity against the inhibitor of this dimeric enzyme. Inhibition of monomeric OMPLA solubilized in hexadecyl-N,N-dimethyl-1-ammonio-3-propanesulfonate resulted in an equimolar monophasic release of PNP, concurrent with the loss of enzymatic activity (t1/2 = 14 min). The half-of-the-sites reactivity is discussed in view of the dimeric nature of this enzyme.

Documentation of particle-size analyzer time series, and discrete suspended-sediment and bed-sediment sample data collection, Niobrara River near Spencer, Nebraska, October 2014

USGS Publications Warehouse

Schaepe, Nathaniel J.; Coleman, Anthony M.; Zelt, Ronald B.

2018-04-06

The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, monitored a sediment release by Nebraska Public Power District from Spencer Dam located on the Niobrara River near Spencer, Nebraska, during the fall of 2014. The accumulated sediment behind Spencer Dam ordinarily is released semiannually; however, the spring 2014 release was postponed until the fall. Because of the postponement, the scheduled fall sediment release would consist of a larger volume of sediment. The larger than normal sediment release expected in fall 2014 provided an opportunity for the USGS and U.S. Army Corps of Engineers to improve the understanding of sediment transport during reservoir sediment releases. A primary objective was to collect continuous suspended-sediment data during the first days of the sediment release to document rapid changes in sediment concentrations. For this purpose, the USGS installed a laser-diffraction particle-size analyzer at a site near the outflow of the dam to collect continuous suspended-sediment data. The laser-diffraction particle-size analyzer measured volumetric particle concentration and particle-size distribution from October 1 to 2 (pre-sediment release) and October 5 to 9 (during sediment release). Additionally, the USGS manually collected discrete suspended-sediment and bed-sediment samples before, during, and after the sediment release. Samples were collected at two sites upstream from Spencer Dam and at three bridges downstream from Spencer Dam. The resulting datasets and basic metadata associated with the datasets were published as a data release; this report provides additional documentation about the data collection methods and the quality of the data.

Calcium regulates vesicle replenishment at the cone ribbon synapse

PubMed Central

Babai, Norbert; Bartoletti, Theodore M.; Thoreson, Wallace B.

2010-01-01

Cones release glutamate-filled vesicles continuously in darkness and changing illumination modulates this release. Because sustained release in darkness is governed by vesicle replenishment rates, we analyzed how cone membrane potential regulates replenishment. Synaptic release from cones was measured by recording post-synaptic currents in Ambystoma tigrinum horizontal or OFF bipolar cells evoked by depolarization of simultaneously voltage-clamped cones. We measured replenishment after attaining a steady-state between vesicle release and replenishment using trains of test pulses. Increasing Ca2+ currents (ICa) by changing the test step from −30 to −10 mV increased replenishment. Lengthening −30 mV test pulses to match the Ca2+ influx during 25 ms test pulses to −10 mV produced similar replenishment rates. Reducing Ca2+ driving force by using test steps to +30 mV slowed replenishment. Using UV flashes to reverse inhibition of ICa by nifedipine accelerated replenishment. Increasing [Ca2+]i by flash photolysis of caged Ca2+ also accelerated replenishment. Replenishment, but not the initial burst of release, was enhanced by using an intracellular Ca2+ buffer of 0.5 mM EGTA rather than 5 mM EGTA, and diminished by 1 mM BAPTA. This suggests that although release and replenishment and release exhibited similar Ca2+-dependencies, release sites are <200 nm from Ca2+ channels but replenishment sites are >200 nm away. Membrane potential thus regulates replenishment by controlling Ca2+ influx, principally by effects on replenishment mechanisms but also by altering releasable pool size. This in turn provides a mechanism for converting changes in light intensity into changes in sustained release at the cone ribbon synapse. PMID:21106825

Light induced cytosolic drug delivery from liposomes with gold nanoparticles.

PubMed

Lajunen, Tatu; Viitala, Lauri; Kontturi, Leena-Stiina; Laaksonen, Timo; Liang, Huamin; Vuorimaa-Laukkanen, Elina; Viitala, Tapani; Le Guével, Xavier; Yliperttula, Marjo; Murtomäki, Lasse; Urtti, Arto

2015-04-10

Externally triggered drug release at defined targets allows site- and time-controlled drug treatment regimens. We have developed liposomal drug carriers with encapsulated gold nanoparticles for triggered drug release. Light energy is converted to heat in the gold nanoparticles and released to the lipid bilayers. Localized temperature increase renders liposomal bilayers to be leaky and triggers drug release. The aim of this study was to develop a drug releasing system capable of releasing its cargo to cell cytosol upon triggering with visible and near infrared light signals. The liposomes were formulated using either heat-sensitive or heat- and pH-sensitive lipid compositions with star or rod shaped gold nanoparticles. Encapsulated fluorescent probe, calcein, was released from the liposomes after exposure to the light. In addition, the pH-sensitive formulations showed a faster drug release in acidic conditions than in neutral conditions. The liposomes were internalized into human retinal pigment epithelial cells (ARPE-19) and human umbilical vein endothelial cells (HUVECs) and did not show any cellular toxicity. The light induced cytosolic delivery of calcein from the gold nanoparticle containing liposomes was shown, whereas no cytosolic release was seen without light induction or without gold nanoparticles in the liposomes. The light activated liposome formulations showed a controlled content release to the cellular cytosol at a specific location and time. Triggering with visual and near infrared light allows good tissue penetration and safety, and the pH-sensitive liposomes may enable selective drug release in the intracellular acidic compartments (endosomes, lysosomes). Thus, light activated liposomes with gold nanoparticles are an attractive option for time- and site-specific drug delivery into the target cells. Copyright © 2015 Elsevier B.V. All rights reserved.

Polymer-based delivery systems for support and delivery of bacteriophages

NASA Astrophysics Data System (ADS)

Brown, Alyssa Marie

One of the most urgent problems in the fields of medicine and agriculture is the decreasing effectiveness of antibiotics. Once a miracle drug, antibiotics have recently become associated with the creation of antibiotic-resistant bacteria. The main limitations of these treatments include lack of both adaptability and specificity. To overcome these shortcomings of current antibiotic treatments, there has been a renewed interest in bacteriophage research. Bacteriophages are naturally-occurring viruses that lyse bacteria. They are highly specific, with each bacteriophage type lysing a narrow range of bacteria strains. Bacteriophages are also ubiquitous biological entities, populating environments where bacterial growth is supported. Just as humans are exposed to bacteria in their daily lives, we are exposed to bacteriophages as well. To use bacteriophages in practical applications, they must be delivered to the site of an infection in a controlled-release system. Two systems were studied to observe their support of bacteriophage lytic activity, as well as investigate the possibility of controlling bacteriophage release rates. First, hydrogels were studied, using crosslinking and blending techniques to achieve a range of release profiles. Second, polyanhydride microparticles were studied, evaluating release rates as a function of monomer chemistries.

Reduction-responsive PEtOz-SS-PCL micelle with tailored size to overcome blood-brain barrier and enhance doxorubicin antiglioma effect.

PubMed

Li, Yuling; Baiyang, Li; Leran, Bu; Zhen, Wang; Yandong, Xie; Baixiang, Du; Dandan, Zhu; Yufu, Zhu; Jun, Liang; Rutong, Yu; Hongmei, Liu

2017-11-01

A series of novel reduction-responsive micelles with tailored size were designed and prepared to release doxorubicin (DOX) for treating glioma, which were developed based on amphiphilic block copolymer poly (2-ethyl-2-oxazoline)-b-poly (ε-caprolactone) (PEtOz-SS-PCL) and the micelle size could be regulated by designing the polymer structure. The DOX-loaded PEtOz-SS-PCL micelles had small size and rapid drug release in reductive intracellular environments. Biodistribution and in vivo imaging studies in C6 glioma mice tumor model showed that DOX loaded PEtOz-SS-PCL43 micelles with the smallest size had superior accumulation and fast drug release in tumor sites. In vivo antitumor activity demonstrated that DOX-loaded PEtOz-SS-PCL43 micelles improved antitumor efficacy in contrast to PEtOz-SS-PCL micelles with larger size toward the orthotopic C6-Luci cells-bearing mice. This study shows great potential in tailoring the micelle size and introducing the responsive bonds or compartment for intracellular drug delivery and release in glioma treatment by designing the architecture of the polymer.

Synthesis, characterization and in vitro cytotoxicity analysis of a novel cellulose based drug carrier for the controlled delivery of 5-fluorouracil, an anticancer drug

NASA Astrophysics Data System (ADS)

Anirudhan, Thayyath S.; Nima, Jayachandran; Divya, Peethambaran L.

2015-11-01

The present investigation concerns the development and evaluation of a novel drug delivery system, aminated-glycidylmethacrylate grafted cellulose-grafted polymethacrylic acid-succinyl cyclodextrin (Cell-g-(GMA/en)-PMA-SCD) for the controlled release of 5-Fluorouracil, an anticancer drug. The prepared drug carrier was characterized by FT-IR, XRD and SEM techniques. Binding kinetics and isotherm studies of 5-FU onto Cell-g-(GMA/en)-PMA-SCD were found to follow pseudo-second-order and Langmuir model respectively. Maximum binding capacity of drug carrier was found to be 149.09 mg g-1 at 37 °C. Swelling studies, in vitro release kinetics, drug loading efficiency and encapsulation efficiency of Cell-g-(GMA/en)-PMA-SCD were studied. The release kinetics was analyzed using Ritger-Peppas equation at pH 7.4. Cytotoxicity analysis on MCF-7 (human breast carcinoma) cells indicated that the drug carrier shows sustained and controlled release of drug to the target site. Hence, it is evident from this investigation that Cell-g-(GMA/en)-PMA-SCD could be a promising carrier for 5-FU.

Characterization of Polycaprolactone and Rice Husk Silica Composite (PCL-SiO2) by E-Spinning to Apply Supporter for Drug Release

NASA Astrophysics Data System (ADS)

Song, Sinae; Hilonga, Askwar; Taik Kim, Hee

2018-03-01

Polycaprolactone (PCL) is an interesting material to apply biomedical field owing to its biodegradability and biocompatibility which is suitable for a specific site with longer healing times. Blending the polymer with other materials has degradation property improved with the effective and economic method. This study was conducted to fabricate supporter based on Polycaprolactone and Rice husk silica (PCL-SiO2) by using electrospinning. Nano-porous silica in the composite was synthesized from rice husk having properties of economic, eco-friendly and high surface area. It drew to enhance the amount of drug loading in the carrier. Electrospinning technique is used to fabricate fibrous component by optimization condition obtained from previous mechanical properties experiments. Release experiment was carried out by the degree of dye absorbance at 544nm by ultraviolet–visible spectroscopy, the RhB in SiO2 alternative drug for modelling of drug release was released for 1 ~ 20 days at 37°C in phosphate buffer. Furthermore, the Mechanical property was confirmed by DSC, TGA. Morphology and degree of biodegradation were shown as SEM images and EDS.

A comparison of on-line and off-line bioaerosol measurements at a biowaste site.

PubMed

Feeney, Patrick; Rodríguez, Santiago Fernández; Molina, Rafael; McGillicuddy, Eoin; Hellebust, Stig; Quirke, Michael; Daly, Shane; O'Connor, David; Sodeau, John

2018-06-01

An air measurement campaign was carried out at a green-waste composting site in the South of Ireland during Spring 2016. The aim was to quantify and identify the levels of Primary Biological Aerosol Particles (PBAP) that were present using the traditional off-line, impaction/optical microscopy method alongside an on-line, spectroscopic approach termed WIBS (Wideband Integrated Bioaerosol Sensor), which can provide number concentrations, sizes and "shapes" of airborne PBAP in real-time by use of Light Induced Fluorescence (LIF). The results from the two techniques were compared in order to validate the use of the spectroscopic method for determining the releases of the wide-range of PBAP present there as a function of site activity and meteorological conditions. The seven-day monitoring period undertaken was much longer than any real-time studies that have been previously performed and allowed due comparison between weekday (working) activities at the site and weekend (closed) releases. The time-span also allowed relationships between site activities like turning, agitation or waste delivery and the WIBS data to be determined in a quantitative manner. This information cannot be obtained with the Andersen Sampling methods generally employed at green-waste management sites. Furthermore, few specific bioaerosol types other than Aspergillus fumigatus, are identified using the traditional protocols employed for site licensing purposes. Here though the co-location of WIBS with the impaction instrument made it possible to identify the real-time release behaviour of a specific plant pathogenic spore, Ustilago maydis, present after green-waste deliveries were made by a local distillery. Copyright © 2018 Elsevier Ltd. All rights reserved.

In-vitro release and permeation studies of ketoconazole from optimized dermatological vehicles using powder, nanoparticles and solid dispersion forms of drug

NASA Astrophysics Data System (ADS)

Mohammed, Irfan A.

To optimize the clinical efficacy of Ketoconazole from an externally applied product, this project was undertaken to evaluate the drug release/permeation profile from various dermatological vehicles using regular powder, nanoparticles and solid dispersion forms with reduced level of drug. Nanoparticles of drug were prepared by wet media milling method using Polyvinylpyrrolidone (PVP-10K) as a stabilizer. The nanoparticles were in the size range of 250-300nm. Solid dispersion was prepared by solvent evaporation method using drug to PVP-10K at a weight ratio of (1:2). Formulations containing 1% w/w drug were developed using HPMC gel, Carbomer gel and a cationic cream as the vehicles. Penetration enhancers including propylene glycol (PG), dimethylsulfoxide (DMSO) and polyethylene glycol 400 (PEG-400) at various levels were evaluated. A commercial 2% w/w ketoconazole product was included as a control for comparison. Studies were carried out with Franz Diffusion Cells using cellulose membrane and human cadaver skin for two and six hour studies. Among the formulations evaluated, the general rank order of the drug release through the cellulose membrane was observed to be: HPMC gel base > Anionic gel base > Cationic gel base > Commercial product. The addition of penetration enhancers showed variable effects in all samples evaluated. However, the HPMC gel-based vehicle showed significant effect in enhancing the drug release in the presence of DMSO. The formulation containing 1% w/w ketoconazole and 20% w/w DMSO gave a maximum drug release of 20.21% when compared to only 1.60% from the commercial product. This represents a twelve fold increase in the release of ketoconazole from the formulation. Furthermore, when the optimum gel-based formulation containing 1% w/w ketoconazole was studied over an extended period of 6 hours, it gave 36.01% drug release from the sample formulation compared to only 2.00% from the commercial product. Finally, this formulation was selected to study for its drug release/permeation profile using the human cadaver skin as the diffusion barrier. Here, as expected, the drug release from both the formulations tested was significantly reduced due to the resistance posed by the skin. After 6 hours, the drug release form the commercial product was 0.17% when compared to 2.80% from the optimum formulation. Once again, this indicated that the experimental formulation exhibits superior drug release dynamics. The selected formulations were further evaluated for their in-vitro anti-fungal activities using yeast microorganisms. The results correlated to the in-vitro drug release profile, where HPMC based formulations exhibited a greater area of zone of inhibition for the growth of microorganisms when compared to diminutive area of zone of inhibition for the commercial product. The release data from all the samples were treated to calculate various physical parameters including: diffusion co-efficient, partition co-efficient, steady state flux and lag period etc. Interestingly, the values for the steady state flux and diffusion coefficient were found to be the highest from the optimum formulation and the values for the lag time and partition coefficient were observed to be the lowest. This supports the evidence that the drug from this formulation is readily diffusible to the skin at a steady rate after its application at the site. In-vitro drug diffusion studies and in-vitro anti-fungal studies proved useful in screening various dermatological formulations of ketoconazole compared to the commercial product containing 2% w/w drug. The HPMC based optimum formulation with reduced level of drug represents 15 folds increase through human cadaver skin and also exhibited augmented anti-fungal activity. This supports that by using an appropriate vehicle and proper incorporation of drug, one can optimize the drug release from topical formulation for maximum therapeutic effect.

Mercury(II) sorption to two Florida Everglades peat--Evidence for strong and weak binding and competition by dissolved organic matter released from the peat

USGS Publications Warehouse

Drexel, R. Todd; Haitzer, Markus; Ryan, Joseph N.; Aiken, George R.; Nagy, Kathryn L.

2002-01-01

The binding of mercury(II) to two peats from Florida Everglades sites with different rates of mercury methylation was measured at pH 6.0 and 0.01 M ionic strength. The mercury(II) sorption isotherms, measured over a total mercury(II) range of 10-7.4 to 10-3.7 M, showed the competition for mercury(II) between the peat and dissolved organic matter released from the peat and the existence of strong and weak binding sites for mercury(II). Binding was portrayed by a model accounting for strong and weak sites on both the peat and the released DOM. The conditional binding constants (for which the ligand concentration was set as the concentration of reduced sulfur in the organic matter as measured by X-ray absorption near-edge structure spectroscopy) determined for the strong sites on the two peats were similar (Kpeat,s = 1021.8±0.1and 1022.0±0.1 M-1), but less than those determined for the DOM strong sites (Kdom,s = 1022.8±0.1and 1023.2±0.1 M-1), resulting in mercury(II) binding by the DOM at low mercury(II) concentrations. The magnitude of the strong site binding constant is indicative of mercury(II) interaction with organic thiol functional groups. The conditional binding constants determined for the weak peat sites (Kpeat,w = 1011.5±0.1 and 1011.8±0.1 M-1) and weak DOM sites (Kdom,w = 108.7±3.0 and 107.3±4.5 M-1) were indicative of mercury(II) interaction with carboxyl and phenol functional groups.

An analysis of the potential for Glen Canyon Dam releases to inundate archaeological sites in the Grand Canyon, Arizona

USGS Publications Warehouse

Sondossi, Hoda A.; Fairley, Helen C.

2014-01-01

The development of a one-dimensional flow-routing model for the Colorado River between Lees Ferry and Diamond Creek, Arizona in 2008 provided a potentially useful tool for assessing the degree to which varying discharges from Glen Canyon Dam may inundate terrestrial environments and potentially affect resources located within the zone of inundation. Using outputs from the model, a geographic information system analysis was completed to evaluate the degree to which flows from Glen Canyon Dam might inundate archaeological sites located along the Colorado River in the Grand Canyon. The analysis indicates that between 4 and 19 sites could be partially inundated by flows released from Glen Canyon Dam under current (2014) operating guidelines, and as many as 82 archaeological sites may have been inundated to varying degrees by uncontrolled high flows released in June 1983. Additionally, the analysis indicates that more of the sites currently (2014) proposed for active management by the National Park Service are located at low elevations and, therefore, tend to be more susceptible to potential inundation effects than sites not currently (2014) targeted for management actions, although the potential for inundation occurs in both groups of sites. Because of several potential sources of error and uncertainty associated with the model and with limitations of the archaeological data used in this analysis, the results are not unequivocal. These caveats, along with the fact that dam-related impacts can involve more than surface-inundation effects, suggest that the results of this analysis should be used with caution to infer potential effects of Glen Canyon Dam on archaeological sites in the Grand Canyon.

Secreted phospholipase A(2) as a new enzymatic trigger mechanism for localised liposomal drug release and absorption in diseased tissue.

PubMed

Davidsen, Jesper; Jørgensen, Kent; Andresen, Thomas L; Mouritsen, Ole G

2003-01-10

Polymer-coated liposomes can act as versatile drug-delivery systems due to long vascular circulation time and passive targeting by leaky blood vessels in diseased tissue. We present an experimental model system illustrating a new principle for improved and programmable drug-delivery, which takes advantage of an elevated activity of secretory phospholipase A(2) (PLA(2)) at the diseased target tissue. The secretory PLA(2) hydrolyses a lipid-based proenhancer in the carrier liposome, producing lyso-phospholipids and free fatty acids, which are shown in a synergistic way to lead to enhanced liposome destabilization and drug release at the same time as the permeability of the target membrane is enhanced. Moreover, the proposed system can be made thermosensitive and offers a rational way for developing smart liposome-based drug delivery systems. This can be achieved by incorporating specific lipid-based proenhancers or prodestabilisers into the liposome carrier, which automatically becomes activated by PLA(2) only at the diseased target sites, such as inflamed or cancerous tissue.

A Graphene-Based Biosensing Platform Based on Regulated Release of an Aptameric DNA Biosensor

PubMed Central

Mao, Yu; Chen, Yongli; Li, Song; Lin, Shuo; Jiang, Yuyang

2015-01-01

A novel biosensing platform was developed by integrating an aptamer-based DNA biosensor with graphene oxide (GO) for rapid and facile detection of adenosine triphosphate (ATP, as a model target). The DNA biosensor, which is locked by GO, is designed to contain two sensing modules that include recognition site for ATP and self-replication track that yields the nicking domain for Nt.BbvCI. By taking advantage of the different binding affinity of single-stranded DNA, double-stranded DNA and aptamer-target complex toward GO, the DNA biosensor could be efficiently released from GO in the presence of target with the help of a complementary DNA strand (CPDNA) that partially hybridizes to the DNA biosensor. Then, the polymerization/nicking enzyme synergetic isothermal amplification could be triggered, leading to the synthesis of massive DNA amplicons, thus achieving an enhanced sensitivity with a wide linear dynamic response range of four orders of magnitude and good selectivity. This biosensing strategy expands the applications of GO-DNA nanobiointerfaces in biological sensing, showing great potential in fundamental research and biomedical diagnosis. PMID:26569239

A Graphene-Based Biosensing Platform Based on Regulated Release of an Aptameric DNA Biosensor.

PubMed

Mao, Yu; Chen, Yongli; Li, Song; Lin, Shuo; Jiang, Yuyang

2015-11-09

A novel biosensing platform was developed by integrating an aptamer-based DNA biosensor with graphene oxide (GO) for rapid and facile detection of adenosine triphosphate (ATP, as a model target). The DNA biosensor, which is locked by GO, is designed to contain two sensing modules that include recognition site for ATP and self-replication track that yields the nicking domain for Nt.BbvCI. By taking advantage of the different binding affinity of single-stranded DNA, double-stranded DNA and aptamer-target complex toward GO, the DNA biosensor could be efficiently released from GO in the presence of target with the help of a complementary DNA strand (CPDNA) that partially hybridizes to the DNA biosensor. Then, the polymerization/nicking enzyme synergetic isothermal amplification could be triggered, leading to the synthesis of massive DNA amplicons, thus achieving an enhanced sensitivity with a wide linear dynamic response range of four orders of magnitude and good selectivity. This biosensing strategy expands the applications of GO-DNA nanobiointerfaces in biological sensing, showing great potential in fundamental research and biomedical diagnosis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bechtel Nevada

The Nevada Test Site Environmental Report 2003 was prepared by Bechtel Nevada to meet the requirements and guidelines of the U.S. Department of Energy and the information needs of the public. This report is meant to be useful to members of the public, public officials, regulators, and Nevada Test Site contractors. The Executive Summary strives to present in a concise format the purpose of the document, the NTS mission and major programs, a summary of radiological releases and doses to the public resulting from site operations, a summary of non-radiological releases, and an overview of the Nevada Test Site Environmentalmore » Management System. The Executive Summary, combined with the following Compliance Summary, are written to meet all the objectives of the report and to be stand-alone sections for those who choose not to read the entire document.« less

Radiological criteria for underground nuclear tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malik, J.S.; Brownlee, R.R.; Costa, C.F.

1981-04-01

The radiological criteria for the conduct of nuclear tests have undergone many revisions with the current criteria being 0.17 rad for uncontrolled populations and 0.5 rad for controllable populations. Their effect upon operations at the Nevada Test Site and the current off-site protective plans are reviewed for areas surrounding the Site. The few accidental releases that have occurred are used to establish estimates of probability of release and of hazard to the population. These are then put into context by comparing statistical data on other accidents and cataclysms. The guidelines established by DOE Manual Chapter MC-0524 have never been exceededmore » during the entire underground nuclear test program. The probability of real hazard to off-site populations appears to be sufficiently low as not to cause undue concern to the citizenry.« less

Nevada Test Site Environmental Report 2007

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cathy Wills

2008-09-01

The Nevada Test Site Environmental Report 2007 (NTSER) was prepared to meet the information needs of the public and the requirements and guidelines of the U.S. Department of Energy (DOE) for annual site environmental reports. It was prepared by National Security Technologies, LLC (NSTec). This Executive Summary presents the purpose of the document, the major programs conducted at the Nevada Test Site (NTS), NTS key environmental initiatives, radiological releases and potential doses to the public resulting from site operations, a summary of nonradiological releases, implementation status of the NTS Environmental Management System, a summary of compliance with environmental regulations, pollutionmore » prevention and waste minimization accomplishments, and significant environmental accomplishments. Much of the content of this Executive Summary is also presented in a separate stand-alone pamphlet titled Nevada Test Site Environmental Report Summary 2007. This NTSER was prepared to satisfy DOE Order 231.1A, Environment, Safety and Health Reporting. Its purpose is to (1) report compliance status with environmental standards and requirements, (2) present results of environmental monitoring of radiological and nonradiological effluents, (3) report estimated radiological doses to the public from releases of radioactive material, (4) summarize environmental incidents of noncompliance and actions taken in response to them, (5) describe the NTS Environmental Management System and characterize its performance, and (6) highlight significant environmental programs and efforts. This report meets these objectives for the NTS and three offsite Nevada facilities mentioned in this report.« less

Detection of site specific glycosylation in proteins using flow cytometry†

PubMed Central

Jayakumar, Deepak; Marathe, Dhananjay D.; Neelamegham, Sriram

2009-01-01

We tested the possibility that it is possible to express unique peptide probes on cell surfaces and detect site-specific glycosylation on these peptides using flow cytometry. Such development can enhance the application of flow cytometry to detect and quantify post-translational modifications in proteins. To this end, the N-terminal section of the human leukocyte glycoprotein PSGL-1 (P-selectin glycoprotein ligand-1) was modified to contain a poly-histidine tag followed by a proteolytic cleavage site. Amino acids preceding the cleavage site have a single O-linked glycosylation site. The recombinant protein called PSGL-1 (HT) was expressed on the surface of two mammalian cell lines, CHO and HL-60, using a lentiviral delivery approach. Results demonstrate that the N-terminal portion of PSGL-1 (HT) can be released from these cells by protease, and the resulting peptide can be readily captured and detected using cytometry-bead assays. Using this strategy, the peptide was immunoprecipitated onto beads bearing mAbs against either the poly-histidine sequence or the human PSGL-1. The carbohydrate epitope associated with the released peptide was detected using HECA-452 and CSLEX-1, monoclonal antibodies that recognize the sialyl Lewis-X epitope. Finally, the peptide released from cells could be separated and enriched using nickel chelate beads. Overall, such an approach that combines recombinant protein expression with flow cytometry, may be useful to quantify changes in site-specific glycosylation for basic science and clinical applications. PMID:19735085

Provisional Advisory Levels (PALs) for Hazardous Agents ...

EPA Pesticide Factsheets

Technical Brief PROVISIONAL ADVISORY LEVELS. Few health-based guidelines are available to inform decisions regarding the reoccupation of buildings or sites, or the re-use of water resources, following their contamination through the accidental or intentional release of toxic chemicals or chemical warfare agents, or following a large-scale disaster. To address this need, EPA/ORD’s National Homeland Security Research Center (NHSRC) develops health-based Provisional Advisory Levels (PALs) for high priority chemicals including toxic industrial chemicals and chemical warfare agents, for both inhalation and oral exposures. Oral PALs are targeted to drinking water ingestion, but are applicable to other oral exposures such as soil ingestion. This product will be used as a hand-out at professional meetings to promote awareness of NHSRC's Provisional Advisory values. It will be posted on the intra and internet sites describing activities and products of EPA/ORD/NHSRC.

Preparation, characterization, in vitro drug release, and cellular interactions of tailored paclitaxel releasing polyethylene oxide films for drug-coated balloons.

PubMed

Anderson, Jordan A; Lamichhane, Sujan; Remund, Tyler; Kelly, Patrick; Mani, Gopinath

2016-01-01

Drug-coated balloons (DCBs) are used to treat various cardiovascular diseases. Currently available DCBs carry drug on the balloon surface either solely or using different carriers. Several studies have shown that a significant amount of drug is lost in the blood stream during balloon tracking to deliver only a sub-therapeutic level of drug at the treatment site. This research is focused on developing paclitaxel (PAT) loaded polyethylene oxide (PEO) films (PAT-PEO) as a controlled drug delivery carrier for DCBs. An array of PAT-PEO films were developed in this study to provide tailored release of >90% of drug only at specific time intervals, which is the time frame required for carrying out balloon-based therapy. The characterizations of PAT-PEO films using SEM, FTIR, and DSC showed that the films developed were homogenous and the PAT was molecularly dispersed in the PEO matrix. Mechanical tests showed that most PAT-PEO films developed were flexible and ductile, with yield and tensile strengths not affected after PAT incorporation. The viability, proliferation, morphology, and phenotype of smooth muscle cells (SMCs) interacted with control-PEO and PAT-PEO films were investigated. All control-PEO and PAT-PEO films showed a significant inhibitory effect on the growth of SMCs, with the degree of inhibition strongly dependent on the w/v% of the polymer used. The PAT-PEO coating was produced on the balloons. The integrity of PAT-PEO coating was well maintained without any mechanical defects occurring during balloon inflation or deflation. The drug release studies showed that only 15% of the total PAT loaded was released from the balloons within the initial 1min (typical balloon tracking time), whereas 80% of the PAT was released between 1min and 4min (typical balloon treatment time). Thus, this study demonstrated the use of PEO as an alternate drug delivery system for the balloons. Atherosclerosis is primarily responsible for cardiovascular diseases (CVDs) in millions of patients every year. Drug-coated balloons (DCBs) are commonly used to treat various CVDs. However, in several currently used DCBs, a significant amount of drug is lost in the blood stream during balloon tracking to deliver only a sub-therapeutic level of drug at the treatment site. In this study, paclitaxel containing polyethylene oxide (PEO) films were developed to provide unique advantages including drug release profiles specifically tailored for balloon-based therapy, homogeneous films with molecularly dispersed drug, flexible and ductile films, and exhibits significant inhibitory effect on smooth muscle cell growth. Thus, this study demonstrated the use of PEO as an alternate drug delivery platform for DCBs to improve its efficacy. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Discovery of Highly Selective and Nanomolar Carbamate-Based Butyrylcholinesterase Inhibitors by Rational Investigation into Their Inhibition Mode.

PubMed

Sawatzky, Edgar; Wehle, Sarah; Kling, Beata; Wendrich, Jan; Bringmann, Gerhard; Sotriffer, Christoph A; Heilmann, Jörg; Decker, Michael

2016-03-10

Butyrylcholinesterase (BChE) is a promising target for the treatment of later stage cognitive decline in Alzheimer's disease. A set of pseudo-irreversible BChE inhibitors with high selectivity over hAChE was synthesized based on carbamates attached to tetrahydroquinazoline scaffolds with the 2-thiophenyl compound 2p as the most potent inhibitor of eqBChE (KC = 14.3 nM) and also of hBChE (KC = 19.7 nM). The inhibitors transfer the carbamate moiety onto the active site under release of the phenolic tetrahydroquinazoline scaffolds that themselves act as neuroprotectants. By combination of kinetic data with molecular docking studies, a plausible binding model was probed describing how the tetrahydroquinazoline scaffold guides the carbamate into a close position to the active site. The model explains the influence of the carrier scaffold onto the affinity of an inhibitor just before carbamate transfer. This strategy can be used to utilize the binding mode of other carbamate-based inhibitors.

Microbial processes influencing the transport, fate and groundwater impacts of fuel ethanol releases.

PubMed

Ma, Jie; Rixey, William G; Alvarez, Pedro J J

2013-06-01

Fuel releases that impact groundwater are a common occurrence, and the growing use of ethanol as a transportation biofuel is increasing the likelihood of encountering ethanol in such releases. Microorganisms play a critical role in the fate of ethanol-blended fuel releases, often determining their region of influence and potential impacts. This review summarizes current understanding on the biogeochemical footprint of such releases and the factors that influence their natural attenuation. Implications for site investigation, risk assessment and remediation strategies are also addressed along with research priorities. Copyright © 2012 Elsevier Ltd. All rights reserved.

National Stormwater Calculator: Low Impact Development ...

EPA Pesticide Factsheets

Stormwater discharges continue to cause impairment of our Nation’s waterbodies. EPA has developed the National Stormwater Calculator (SWC) to help support local, state, and national stormwater management objectives to reduce runoff through infiltration and retention using green infrastructure practices as low impact development (LID) controls. The primary focus of the SWC is to inform site developers on how well they can meet a desired stormwater retention target with and without the use of green infrastructure. It can also be used by landscapers and homeowners. Platform. The SWC is a Windows-based desktop program that requires an internet connection. A mobile web application version that will be compatible with all operating systems is currently being developed and is expected to be released in the fall of 2017.Cost Module. An LID cost estimation module within the application allows planners and managers to evaluate LID controls based on comparison of regional and national project planning level cost estimates (capital and average annual maintenance) and predicted LID control performance. Cost estimation is accomplished based on user-identified size configuration of the LID control infrastructure and other key project and site-specific variables. This includes whether the project is being applied as part of new development or redevelopment and if there are existing site constraints.Climate Scenarios. The SWC allows users to consider how runoff may vary based

USING SIMPLE MATHEMATICAL MODELS FOR ESTIMATING IMPACTS TO GROUND WATER AT PETROLEUM RELEASE SITES - WORKSHOP

EPA Science Inventory

Regulators and consultants alike are routinely tasked with predicting potential future impacts to ground water resources from leaking underground storage tank (LUST) sites. Site data is usually sparse, variable, and uncertain at best. However, this type of data can be evaluated ...

Mohawk Tannery Hazardous Waste Site in New Hampshire included on EPA List of Targeted for Immediate Attention

EPA Pesticide Factsheets

Today, the U.S. Environmental Protection Agency released the list of Superfund sites that Administrator Pruitt has targeted for immediate and intense attention. The former Mohawk Tannery facility (a.k.a. Granite State Leathers) is one of the 21 sites on th

Release of chlorinated, brominated and mixed halogenated dioxin-related compounds to soils from open burning of e-waste in Agbogbloshie (Accra, Ghana).

PubMed

Tue, Nguyen Minh; Goto, Akitoshi; Takahashi, Shin; Itai, Takaaki; Asante, Kwadwo Ansong; Kunisue, Tatsuya; Tanabe, Shinsuke

2016-01-25

Although complex mixtures of dioxin-related compounds (DRCs) can be released from informal e-waste recycling, DRC contamination in African e-waste recycling sites has not been investigated. This study examined the concentrations of DRCs including chlorinated, brominated, mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in surface soil samples from the Agbogbloshie e-waste recycling site in Ghana. PCDD/F and PBDD/F concentrations in open burning areas (18-520 and 83-3800 ng/g dry, respectively) were among the highest reported in soils from informal e-waste sites. The concentrations of PCDFs and PBDFs were higher than those of the respective dibenzo-p-dioxins, suggesting combustion and PBDE-containing plastics as principal sources. PXDFs were found as more abundant than PCDFs, and higher brominated analogues occurred at higher concentrations. The median total WHO toxic equivalent (TEQ) concentration in open burning soils was 7 times higher than the U.S. action level (1000 pg/g), with TEQ contributors in the order of PBDFs>PCDD/Fs>PXDFs. DRC emission to soils over the e-waste site as of 2010 was estimated, from surface soil lightness based on the correlations between concentrations and lightness, at 200mg (95% confidence interval 93-540 mg) WHO-TEQ over three years. People living in Agbogbloshie are potentially exposed to high levels of not only chlorinated but also brominated DRCs, and human health implications need to be assessed in future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Equations for estimating stand establishment, release, and thinning costs in the Lake States.

Treesearch

Jeffrey T. Olson; Allen L. Lundgren; Dietmar Rose

1978-01-01

Equations for estimating project costs for certain silvicultural treatments in the Lake States have been developed from project records of public forests. Treatments include machine site preparation, hand planting, aerial spraying, prescribed burning, manual release, and thinning.

40 CFR 300.410 - Removal site evaluation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY... preliminary assessment of releases from hazardous waste management facilities may include collection or review... for the release, or any other person, is providing appropriate response, and on-scene monitoring by...

40 CFR 300.410 - Removal site evaluation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY... preliminary assessment of releases from hazardous waste management facilities may include collection or review... for the release, or any other person, is providing appropriate response, and on-scene monitoring by...

40 CFR 300.410 - Removal site evaluation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS NATIONAL OIL AND HAZARDOUS SUBSTANCES POLLUTION CONTINGENCY... preliminary assessment of releases from hazardous waste management facilities may include collection or review... for the release, or any other person, is providing appropriate response, and on-scene monitoring by...

PHYSICAL AND CHEMICAL CONTROL OF RELEASED MICROORGANISMS AT FIELD SITES

EPA Science Inventory

An important consideration in the environmental release of a genetically engineered microorganism (GEM) is the capability for reduction or elimination of GEM populations once their function is completed or if adverse environmental effects are observed. In this study the decontami...

Development of the concept of spatial-temporal mask for testing effects of discharge from well-drilling activities on biological communities.

PubMed

Pulgati, Fernando H; Ayup-Zouain, Ricardo N; Landau, Luiz; Fachel, Jandyra M G

2010-08-01

This paper describes the use of Bayesian spatial models to develop the concept of a spatial-temporal mask for the purpose of identifying regions in which before and after drilling effects are most clearly defined and from which the consequences of exposure of macrofauna and meiofauna to the release of drilling discharges can be evaluated over time. To determine the effects of drilling fluids and drill-cuttings on the marine benthic community, it is essential to know not only where discharged materials ended up within the possible impact area, but also the chemical concentrations to which biota were exposed during and after drilling. Barium and light hydrocarbons were used as chemical tracers for water-based and non-aqueous-based fluids in a shallow water site in the Campos Basin, off the coast of Brazil. Since the site showed evidence of exposure to waste material from earlier drilling, the analysis needed to take into account the background concentrations of these compounds. Using the Bayesian models, concentrations at unsampled sites were predicted and regions altered and previously contaminated were identified.

Process-based reactive transport model to quantify arsenic mobility during aquifer storage and recovery of potable water.

PubMed

Wallis, Ilka; Prommer, Henning; Pichler, Thomas; Post, Vincent; Norton, Stuart B; Annable, Michael D; Simmons, Craig T

2011-08-15

Aquifer storage and recovery (ASR) is an aquifer recharge technique in which water is injected in an aquifer during periods of surplus and withdrawn from the same well during periods of deficit. It is a critical component of the long-term water supply plan in various regions, including Florida, USA. Here, the viability of ASR as a safe and cost-effective water resource is currently being tested at a number of sites due to elevated arsenic concentrations detected during groundwater recovery. In this study, we developed a process-based reactive transport model of the coupled physical and geochemical mechanisms controlling the fate of arsenic during ASR. We analyzed multicycle hydrochemical data from a well-documented affected southwest Floridan site and evaluated a conceptual/numerical model in which (i) arsenic is initially released during pyrite oxidation triggered by the injection of oxygenated water (ii) then largely complexes to neo-formed hydrous ferric oxides before (iii) being remobilized during recovery as a result of both dissolution of hydrous ferric oxides and displacement from sorption sites by competing anions.

Experience of on-site disposal of production uranium-graphite nuclear reactor.

PubMed

Pavliuk, Alexander O; Kotlyarevskiy, Sergey G; Bespala, Evgeny V; Zakharova, Elena V; Ermolaev, Vyacheslav M; Volkova, Anna G

2018-04-01

The paper reported the experience gained in the course of decommissioning EI-2 Production Uranium-Graphite Nuclear Reactor. EI-2 was a production Uranium-Graphite Nuclear Reactor located on the Production and Demonstration Center for Uranium-Graphite Reactors JSC (PDC UGR JSC) site of Seversk City, Tomsk Region, Russia. EI-2 commenced its operation in 1958, and was shut down on December 28, 1990, having operated for the period of 33 years all together. The extra pure grade graphite for the moderator, water for the coolant, and uranium metal for the fuel were used in the reactor. During the operation nitrogen gas was passed through the graphite stack of the reactor. In the process of decommissioning the PDC UGR JSC site the cavities in the reactor space were filled with clay-based materials. A specific composite barrier material based on clays and minerals of Siberian Region was developed for the purpose. Numerical modeling demonstrated the developed clay composite would make efficient geological barriers preventing release of radionuclides into the environment. Copyright © 2018 Elsevier Ltd. All rights reserved.