Effects of temperature and salinity on bioconcentration and toxicokinetics of permethrin in pyrethroid-resistant Hyalella azteca.

Recent studies demonstrated pyrethroid resistance associated with voltage-gated sodium channel mutations in populations of the epibenthic amphipod, Hyalella azteca. Resistant populations were able to tolerate and bioconcentrate pyrethroids at concentrations significantly higher than toxic levels for non-resistant populations. In conjunction with elevated bioconcentration potential, environmental alteration particularly as a result of global climate change is anticipated to significantly alter abiotic parameters including temperature and salinity.

The Power of Nursing Course: An Innovative Online Synchronous Experience.

Background: A nursing didactic and clinical curriculum are missing essential affective experiences to foster a deeper connection to the art of nursing. The Power of Nursing (PON) course was identified as meeting this need. With the coronavirus disease 2019 (COVID-19) pandemic disruption, faculty gained the opportunity to adapt this discovery model course within the bounds of technology.

The Decision-Making Experiences of Caregivers Regarding Feeding Tube Placement in Community-Dwelling Adults: A Descriptive Phenomenological Study.

Percutaneous endoscopic gastrostomy feeding tube placement is multifactorial and considered a lifesaving mechanism, which leads to a host of thoughts and feelings that affect the decision-making experience. As people live longer and the population ages, these decisions often involve the caregivers who have their own experience and therefore can result in caregiver burden and anxiety. A descriptive phenomenological study was conducted to describe and understand the caregiver's decision-making experience regarding percutaneous endoscopic gastrostomy feeding tube placement in community-dwelling adults.

Using a Resuscitation-Based Simulation Activity to Create an Interprofessional Education Activity for Medical, Nursing, and Pharmacy Students.

Introduction: To achieve high-quality, patient-centered care, teaching programs across health professions must prepare their learners to work in effective teams. We created a simulation activity to formatively assess interprofessional objectives in graduating medical, nursing, and pharmacy students. This simulation also gave learners an opportunity to practice clinical airway resuscitation skills.

An Interprofessional Standardized Patient Case for Improving Collaboration, Shared Accountability, and Respect in Team-Based Family Discussions.

Introduction: The science of patient safety demonstrates that good communication is essential for effective interprofessional collaboration.

Methods: We created a low-stakes, formative assessment with which medical students, pharmacy students, and nursing students could practice several of the Interprofessional Education Collaborative competencies. We aimed to enable students to practice collaborative care, respect for other disciplines, and shared accountability.

Can Tenax Extraction Be Used as a Surrogate Exposure Metric for Laboratory-Based Bioaccumulation Tests Using Marine Sediments?

The Tenax technique was used as an alternative exposure metric to assess the bioavailability of polychlorinated biphenyls (PCBs) from contaminated marine sediments. The sediments used were collected from 2 Superfund sites, New Bedford Harbor (MA, USA) and Gould Island (RI, USA). No sieving was conducted for either sediment after arrival, and sediments were stored in stainless steel drums at 2.

Effects of type and quantity of organic carbon on the bioaccessibility of polychlorinated biphenyls in contaminated sediments.

Organic carbon principally controls sorption and desorption of hydrophobic organic compounds in sediments. We investigated the effects of organic carbon type and quantity on compound bioaccessibility. The desorption of 21 polychlorinated biphenyl (PCB) congeners was determined in spiked sediments amended with black carbon, humic acid, and sawdust at either 3 or 6% organic carbon.

Patient Safety Interprofessional Training for Medical, Nursing, and Pharmacy Students.

Introduction: Patient safety education is required in medical, nursing, and pharmacy training, and interprofessional education offers an ideal format for teaching the core concepts of patient safety. This training activity was developed to fulfill interprofessional education core competencies for communication and teamwork and was nested within a required patient safety course taught at a medical school. However, the activity can easily be adapted as a stand-alone offering that can be included in a preclinical doctoring course, offered as an elective, or hosted at a college of nursing or pharmacy.

Methodological and Environmental Impacts on Bioaccessibility Estimates Provided by Single-Point Tenax Extractions.

Single-point Tenax extractions (SPTEs) of hydrophobic organic contaminants provide estimates of bioaccessibility through consistent measures of the chemical concentration initially in the rapidly desorbing fraction in sediment (C ), such that a constant ratio is expected between SPTE and C (C /C , where T is the duration of the SPTE). As environmental factors (i.e.

Optimization of Tenax extraction parameters for polychlorinated biphenyls in contaminated sediments.

Tenax extraction is a chemical technique used to provide a rapid estimate of exposure to chemicals from contaminated sediments. However, an absence of standardization has limited the implementation of Tenax extraction in regulatory venues. In the current study, the operational parameters of extraction solvent volume, Tenax sorption rate from water, and Tenax:OC (organic carbon) ratios were investigated employing polychlorinated biphenyls (PCBs) as model compounds.

The robustness of single-point Tenax extractions of pyrethroids: Effects of the Tenax to organic carbon mass ratio on exposure estimates.

Use of Tenax extractable concentrations to estimate biological exposure to hydrophobic organic contaminants is well documented, yet method variation exists between studies, specifically in the ratio of Tenax mass to organic carbon mass in the sediment (Tenax:OC ratio) being extracted. The effects of this variation on exposure estimates are not well understood. As Tenax is theoretically in direct competition with organic carbon for freely dissolved chemical in sediment interstitial water, varying the Tenax:OC ratio could impact single-point Tenax extraction (SPTE) exposure estimates.

Tenax extraction as a simple approach to improve environmental risk assessments.

It is well documented that using exhaustive chemical extractions is not an effective means of assessing exposure of hydrophobic organic compounds in sediments and that bioavailability-based techniques are an improvement over traditional methods. One technique that has shown special promise as a method for assessing the bioavailability of hydrophobic organic compounds in sediment is the use of Tenax-extractable concentrations. A 6-h or 24-h single-point Tenax-extractable concentration correlates to both bioaccumulation and toxicity.

Tenax extraction of sediments to estimate desorption and bioavailability of hydrophobic contaminants: a literature review.

Characterizing sediment-associated hydrophobic contaminants is problematic, because assessing the total amount of a compound available for chemical exchange with an organism is difficult. To address this, contaminant concentrations have been normalized for specific sediment characteristics (including organic C content) or the chemical activity has been estimated using passive samplers. Another approach to assess compound availability is to determine the extent of readily desorbed compound using resin extractions of sediment slurries.

Passive sampling methods for contaminated sediments: state of the science for organic contaminants.

This manuscript surveys the literature on passive sampler methods (PSMs) used in contaminated sediments to assess the chemical activity of organic contaminants. The chemical activity in turn dictates the reactivity and bioavailability of contaminants in sediment. Approaches to measure specific binding of compounds to sediment components, for example, amorphous carbon or specific types of reduced carbon, and the associated partition coefficients are difficult to determine, particularly for native sediment.

Application of a Tenax model to assess bioavailability of polychlorinated biphenyls in field sediments.

Recent literature has shown that bioavailability-based techniques, such as Tenax extraction, can estimate sediment exposure to benthos. In a previous study by the authors, Tenax extraction was used to create and validate a literature-based Tenax model to predict oligochaete bioaccumulation of polychlorinated biphenyls (PCBs) from sediment; however, its ability to assess sediment remediation was unknown. The present study further tested the Tenax model by examining the impacts of remediation on surface sediment concentrations, Tenax extractable concentrations, and tissue concentrations of laboratory-exposed Lumbriculus variegatus.

Dietary exposure of Antarctic krill to p,p'-DDE: uptake kinetics and toxicological sensitivity in a key polar species.

This study evaluated the dietary uptake kinetics and sublethal toxicity of p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE) in Antarctic krill. The uptake rate constant (characterised by the seawater volume stripped of contaminant sorbed to algae) of 200 ± 0.32 mL g(-1) wet weight h(-1), average absorption efficiency of 86 ± 13% and very low elimination rate constant of 5 × 10(-6) ± 0.

The importance of both potency and mechanism in dose-response analysis: an example from exposure of Pacific herring (Clupea pallasi) embryos to low concentrations of weathered crude oil.

This paper reanalyzes data from an earlier study that used effluents from oiled-gravel columns to assess the toxicity of aqueous fractions of weathered crude oil to Pacific herring embryos and larvae. This reanalysis has implications for future similar investigations, including the observance of two distinct dose-response curves for lethal and sublethal endpoints for different exposures in the same experiment, and the need to consider both potency and slope of dose-response curves for components of a toxicant mixture that shows potentially different toxicity mechanisms/causation. Contrary to conclusions of the original study, the aqueous concentration data cannot support the hypothesis that polycyclic aromatic hydrocarbons (PAHs) were the sole cause of toxicity and that oil toxicity increased with weathering.

Influence of exposure and toxicokinetics on measures of aquatic toxicity for organic contaminants: a case study review.

This theoretical and case study review of dynamic exposures of aquatic organisms to organic contaminants examines variables important for interpreting exposure and therefore toxicity. The timing and magnitude of the absorbed dose change when the dynamics of exposure change. Thus, the dose metric for interpreting toxic responses observed during such exposure conditions is generally limited to the specific experiment and cannot be extrapolated to either other experiments with different exposure dynamics or to field exposures where exposure dynamics usually are different.

Using SPME fibers and Tenax to predict the bioavailability of pyrethroids and chlorpyrifos in field sediments.

The presence of pyrethroids in both urban and agricultural sediments at levels lethal to invertebrates has been well documented. However, variations in bioavailability among sediments make accurate predictions of toxicity based on whole sediment concentrations difficult. A proposed solution to this problem is the use of bioavailability-based estimates, such as solid phase microextraction (SPME) fibers and Tenax beads.

Assessing bioavailability and toxicity of permethrin and DDT in sediment using matrix solid phase microextraction.

Matrix solid phase microextraction (matrix-SPME) was evaluated as a surrogate for the absorbed dose in organisms to estimate bioavailability and toxicity of permethrin and dichlorodiphenyltrichloroethane (DDT) in laboratory-spiked sediment. Sediments were incubated for 7, 28, and 90 days at room temperature to characterize the effect of aging on bioavailability and toxicity. Sediment toxicity was assessed using two freshwater invertebrates, the midge Chironomus dilutus and amphipod Hyalella azteca.

Bioavailability-based toxicity endpoints of bifenthrin for Hyalella azteca and Chironomus dilutus.

Recent studies have determined that techniques, such as solid phase microextraction (SPME) fibers and Tenax beads, can predict bioaccumulation and potentially could predict toxicity for several compounds and species. Toxicity of bifenthrin was determined using two standard sediment toxicity tests with the benthic species Hyalella azteca and Chironomus dilutus in three reference sediments with different characteristics. The objectives of the current study were to establish bioavailability-based median lethal concentrations (LC50) and median effect concentrations (EC50) of the pyrethroid insecticide bifenthrin, compare their ability to assess toxicity to the use of whole sediment concentrations, as well as to make comparisons of the concentrations derived using each method in order to make assessments of accuracy and extrapolation potential.

Application of a Tenax model to assess bioavailability of PCBs in field sediments.

Bioavailability has been estimated in the past using equilibrium partitioning-based biota-sediment accumulation factors. These values are not always reliable using field-collected sediments, however, likely due to varying amounts of different organic carbons, particularly black carbon, in sediments. Therefore, improving approaches to better evaluate contaminant bioavailability in sediment are needed.

Use of solid phase microextraction to estimate toxicity: relating fiber concentrations to body residues--part II.

In the companion paper, solid phase microextraction (SPME) fiber concentrations were used as a dose metric to evaluate the toxicity of hydrophobic pesticides, and concentration-response relationships were found for the hydrophobic pesticides tested in the two test species. The present study extends the use of fiber concentrations to organism body residues to specifically address biotransformation and provide the link to toxic response. Test compounds included the organochlorines p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE); two pyrethroids, permethrin and bifenthrin; and an organophosphate, chlorpyrifos.