Bioavailability of cadmium in inexpensive jewelry.

Objectives: We evaluated the bioavailability of Cd in 86 components of 57 jewelry items found to contain high levels of Cd (> 10,000 ppm) by X-ray fluorescence (XRF), using extractions that simulate mouthing or swallowing of jewelry items.

Methods: We screened jewelry for Cd content by XRF. Bioavailability was measured in two ways.

Mixture toxicity of SN2-reactive soft electrophiles: 1. Evaluation of mixtures containing α-halogenated acetonitriles.

The concept of multiple modes of toxic action denotes that an individual chemical can induce two or more toxic effects within the same series of concentrations, for example, reactive toxicity and narcosis. It appears that such toxicity confounds the ability to develop precise predictions of mixture toxicity and makes it more difficult to clearly link a dose-additive combined effect to agents in the mixture having a single common mechanism of toxic action. This initial study of a three-part series begins to examine this issue in greater detail by testing three α-halogenated acetonitriles: (1) in sham combinations, (2) in true combinations, and (3) with a nonreactive nonpolar narcotic.

Assessment of leaching potential of highly leaded jewelry.

Lead is a potent neurotoxin particularly toxic to young children, and in response to recent poisonings of children and high levels of lead contamination in children's jewelry, US regulatory standards for lead content in these items have become much more stringent. Parents are often advised to throw out suspect items in the trash. While household wastes are generally exempt from consideration as hazardous waste, the potential for leaching of hazardous quantities of lead from such items is unknown.

Direct and indirect effects of invasive plants on soil chemistry and ecosystem function.

Invasive plants have a multitude of impacts on plant communities through their direct and indirect effects on soil chemistry and ecosystem function. For example, plants modify the soil environment through root exudates that affect soil structure, and mobilize and/or chelate nutrients. The long-term impact of litter and root exudates can modify soil nutrient pools, and there is evidence that invasive plant species may alter nutrient cycles differently from native species.

In situ silicone tube microextraction: a new method for undisturbed sampling of root-exuded thiophenes from marigold (Tagetes erecta L.) in soil.

The difficulties of monitoring allelochemical concentrations in soil and their dynamics over time have been a major barrier to testing hypotheses of allelopathic effects. Here, we evaluate three diffusive sampling strategies that employ polydimethylsiloxane (PDMS) sorbents to map the spatial distribution and temporal dynamics of root-exuded thiophenes from the African marigold, Tagetes erecta. Solid phase root zone extraction (SPRE) probes constructed by inserting stainless steel wire into PDMS tubing were used to monitor thiophene concentrations at various depths beneath marigolds growing in PVC pipes.

Strength tracking using the OMNI resistance exercise scale in older men and women.

Strength tracking uses ratings of perceived exertion (RPE) as a reference value to determine changes in strength as a function of a resistance training program. The purpose of this investigation was to determine if the OMNI Resistance Exercise Scale (OMNI-RES) could be used to track training-induced strength changes in older adults. Twenty-two men (64.

Lead contamination of inexpensive seasonal and holiday products.

Lead is a potent neurotoxin and because of this, the US regulatory limit for lead content of paint on items intended for children is 0.06% by weight. There were numerous recalls of name-brand toys in the United States for lead paint contamination during 2007.

The forgetting of stimulus attributes in latent inhibition.

Numerous studies have demonstrated that the forgetting of stimulus attributes is a common occurrence; that is, organisms forget the specific characteristics of training stimuli over long retention intervals, while retaining general information of the training stimuli themselves. However, most studies have examined this effect after a learning episode, and there have been virtually no accounts to test whether the forgetting of attributes occurs for stimuli presented prior to training. Therefore, this experiment was designed to test that possibility, and it examined whether the forgetting of stimulus attributes occurred prior to training for the flavor stimulus in a conditioned taste aversion (CTA) procedure.

RPE at relative intensities after 12 weeks of resistance-exercise training by older adults.

The constant-RPE tracking model monitors progress over the course of exercise training. During aerobic exercise, prior work using this model has demonstrated similar relative intensities pre- and posttraining, while the absolute workload increases posttraining. However, the prediction equation associated with these changes has not been examined during resistance training.

Evaluating minority retention programs: problems encountered and lessons learned from the Ohio science and engineering alliance.

The retention rates for African-Americans, Hispanics, and Native-Americans in science, technology, engineering, and mathematics (STEM) are lower than those of White or Asian college students. In response, the National Science Foundation formed statewide partnerships of universities to develop programs to address this disparity. The deliberations and experiences in evaluating one such partnership are retrospectively reviewed.

A proteome map of the zebrafish (Danio rerio) lens reveals similarities between zebrafish and mammalian crystallin expression.

Purpose: To characterize the crystallin content of the zebrafish lens using two-dimensional gel electrophoresis (2-DE). These data will facilitate future investigations of vertebrate lens development, function, and disease.

Methods: Adult zebrafish lens proteins were separated by 2-DE, and the resulting spots were identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS).

Accessible and total lead in low-cost jewelry items.

The US Consumer Product Safety Commission has proposed a ban on children's metal jewelry containing more than 0.06% lead by weight. This ban would replace the current interim enforcement standard, which also includes a measurement of accessible lead.

Lead contamination of inexpensive plastic jewelry.

The neurological hazards of lead to children are well-known. As a result of recent documented cases of lead poisoning, regulatory attention in the United States has focused on the lead content of children's metal jewelry. By contrast, little is known about the possible hazards of plastic jewelry items.

Time-dependence in mixture toxicity with soft-electrophiles: 2. Effects of relative reactivity level on time-dependent toxicity and combined effects for selected Michael acceptors.

Toxicity assessments for organic chemical mixtures are often described as being approximately additive. Recent mixture studies with soft electrophiles have suggested that agents with less-than fully time-dependent toxicity (TDT) may actually induce toxicity by more than one mode of toxic action within the same series of concentrations. To evaluate this concept further, four Michael acceptor electrophiles, each with a different rate of in chemico reactivity and different level of TDT, were tested with each other and in sham combinations (a single chemical tested as if it were a binary mixture) using the Microtox system.

Solid-phase microextraction method for in vivo measurement of allelochemical uptake.

Solid-phase microextraction (SPME) was used to measure allelochemical uptake by tomato plants in vivo. Exogenously applied 1,8-cineole was rapidly taken up by tomato, with the first traces of cineole being detected in the tomato stem just 1-2 h after a single application of 0.5 mM cineole to soil.

Fractured relationships and the potential for abuse of older men.

Elderly men are an understudied population in the area of abuse and neglect. The typical elder abuse or neglect victim is described as a frail woman. The National Elder Abuse Incidence Study shows men to be victims as well and at higher risk than women for abandonment, the most extreme form of neglect.

Evidence of recycling of lead battery waste into highly leaded jewelry.

Inexpensive highly leaded jewelry, much of it imported from China, remains widely available in the United States. The source materials for these items are unknown. Due to the low cost of much of this trinket jewelry, it seems likely that scrap materials may be used in their manufacture.

Leaded electronic waste is a possible source material for lead-contaminated jewelry.

Highly leaded jewelry, often imported from China, remains widely available in the United States. Leaded electronic waste is exported from the United States to several Asian countries where solder is recovered and circuit boards are stripped of parts in small workshops. To assess whether electronic waste is being recycled into the jewelry, lead, tin and copper content of highly leaded jewelry samples were determined by atomic absorption spectrometry.

Time dependence in mixture toxicity with soft electrophiles: 1. Combined effects of selected SN2- and SNAr-reactive agents with a nonpolar narcotic.

Frequently the toxicity of an organic chemical mixture is close to dose-additive, even when the agents are thought to induce toxicity at different molecular sites of action. These findings appear to conflict with the hypothesis that a strictly dose-additive combined effect will be observed for agents sharing a single molecular site of toxic action within the organism. In this study, several SN2-reactive (alpha-halogen) or S(N)Ar-reactive (halogenated dinitrobenzene) soft electrophiles were tested with a model nonpolar narcotic (NPN) to determine the toxicity of the combinations.

Widespread lead contamination of imported low-cost jewelry in the US.

Recent recalls of lead-contaminated jewelry and the death of a Minnesota child by lead poisoning after swallowing a jewelry charm have highlighted the hazards of leaded jewelry to children. We sought to determine the extent of lead contamination in inexpensive, imported jewelry available in United States retail stores. A total of 139 jewelry items were purchased from ten retail store chains in five different geographic locations.

Face distinctiveness and delayed testing: differential effects on performance and confidence.

The author investigated the effect of delayed testing on participants' memory for distinctive and typical faces. Participants viewed distinctive and typical faces and were then tested for recognition immediately or after a delay of 3, 6, or 12 weeks. Consistent with prior research, analysis of measure of sensitivity (d') showed that participants performed better on distinctive rather than typical faces, and memory performance declined with longer retention intervals between study and testing.

Gene duplication and separation of functions in alphaB-crystallin from zebrafish (Danio rerio).

We previously reported that zebrafish alphaB-crystallin is not constitutively expressed in nervous or muscular tissue and has reduced chaperone-like activity compared with its human ortholog. Here we characterize the tissue expression pattern and chaperone-like activity of a second zebrafish alphaB-crystallin. Expressed sequence tag analysis of adult zebrafish lens revealed the presence of a novel alpha-crystallin transcript designated cryab2 and the resulting protein alphaB2-crystallin.

Chemical mixture toxicity testing with Vibrio fischeri: combined effects of binary mixtures for ten soft electrophiles.

The toxicity of 30 binary combinations of 10 soft electrophiles was examined in Microtox using dose-response curve (DRC) analysis. Chemicals from three groups of soft electrophiles-vinyl Michael acceptors (I--react with a thiol group), dicarbonyl reactive agents (II--react with a primary amine), and alpha-haloactivation compounds (III--react with a thiol group)--were selected for testing to evaluate the relationship between molecular site of chemical action and combined toxic effect. For each combination tested, each single agent was tested alone at six duplicated concentrations and three 1:1 mixtures of the agents were also tested, each at six duplicated concentrations.

Rating perceived exertion during short duration, very high intensity cycle exercise.

This study compared undifferentiated ratings of perceived exertion (RPE) during short duration, very high intensity cycle exercise using high and low resistance. 30 recreationally trained males (24.2 +/- 2.

Biomimetic measurement of allelochemical dynamics in the rhizosphere.

Polydimethylsiloxane (PDMS) materials were used to quantify levels of the photosynthesis inhibitor sorgoleone in the undisturbed rhizosphere of sorghum plants. The materials used included stir bars coated with PDMS (stir bar sorptive extraction), technical grade optical fiber coated with a thin film of PDMS (matrix-solid phase microextraction), and PDMS tubing. PDMS tubing retained the most sorgoleone.