Bioconcentration factors for hydrocarbons and petrochemicals: Understanding processes, uncertainty and predictive model performance.

Fish bioconcentration factors (BCFs) are often used to assess substance-specific bioaccumulation. However, reliable BCF data are limited given the practical challenges of conducting such tests. The objectives of this paper are to describe nine rainbow trout studies performed in our lab using tailored dosing and test designs for obtaining empirical BCFs for 21 test substances; gain insights into the structural features and processes determining the magnitude and uncertainty in observed BCFs; and assess performance of six quantitative structure property relationships (QSPRs) for correctly categorizing bioaccumulation given current regulatory triggers. Resulting mean steady-state BCFs, adjusted to a 5% lipid content, ranged from 12 Lkg-1 for isodecanol to 15,448 Lkg-1 for hexachlorobenzene which served as a positive control. BCFs for hydrocarbons depended on aromatic and saturated ring configurations and position. Uptake clearances appeared to be modulated by gill metabolism and substance bioavailability, while elimination rates were likely influenced by somatic biotransformation. Current approaches for quantifying uncertainty in experimental BCFs, which take into account only variability in measured fish concentrations, were found to underestimate the true uncertainty in this endpoint with important implications for decision-making. The Vega (KNN/Read-Across) QSPR and Arnot-Gobas model yielded the best model performance when compared to measured BCFs generated in this study.

Food Safety Issues Related to Uses of Insects for Feeds and Foods.

Edible insects are expected to become an important nutrient source for animals and humans in the Western world in the near future. However, before insects can be put on the market, the safety of their use for feed and food is warranted. This literature study was prepared to provide an overview of the actual knowledge of possible food safety hazards, including chemical, microbiological, and allergenic agents and prions, to human and animal health upon the use of insects for food and feed, and to highlight data gaps and suggest the way forward. From the data available, heavy metals of concern are cadmium in black soldier fly and arsenic in yellow mealworm larvae. Investigated mycotoxins do not seem to accumulate. Residues of pesticides, veterinary drugs, and hormones, as well as dioxins and PCBs, are sometimes found in insects. Contamination of insects with pathogens to human health is a consequence of a combination of the substrates used and the farming and processing steps applied. Insects harbor a wide variety of microorganisms, and some human pathogenic bacteria may be present. In addition, insects may harbor and transmit parasites. There is no evidence so far insects may harbor pathogenic viruses or prions, but they may act as vectors. Insects and insect-derived products may have allergenic potential. In this review, evidence on some safety aspects is displayed, and data gaps are identified. Recommendations are given for future research to fill the most relevant data gaps.

Uptake of Cadmium, Lead and Arsenic by Tenebrio molitor and Hermetia illucens from Contaminated Substrates.

Insects have potential as a novel source of protein in feed and food production in Europe, provided they can be used safely. To date, limited information is available on the safety of insects, and toxic elements are one of the potential hazards of concern. Therefore, we aimed to investigate the potential accumulation of cadmium, lead and arsenic in larvae of two insect species, Tenebrio molitor (yellow mealworm) and Hermetia illucens (black soldier fly), which seem to hold potential as a source of food or feed. An experiment was designed with 14 treatments, each in triplicate, per insect species. Twelve treatments used feed that was spiked with cadmium, lead or arsenic at 0.5, 1 and 2 times the respective maximum allowable levels (ML) in complete feed, as established by the European Commission (EC). Two of the 14 treatments consisted of controls, using non-spiked feed. All insects per container (replicate) were harvested when the first larva in that container had completed its larval stage. Development time, survival rates and fresh weights were similar over all treatments, except for development time and total live weight of the half of the maximum limit treatment for cadmium of the black soldier fly. Bioaccumulation (bioaccumulation factor > 1) was seen in all treatments (including two controls) for lead and cadmium in black soldier fly larvae, and for the three arsenic treatments in the yellow mealworm larvae. In the three cadmium treatments, concentrations of cadmium in black soldier fly larvae are higher than the current EC maximum limit for feed materials. The same was seen for the 1.0 and 2.0 ML treatments of arsenic in the yellow mealworm larvae. From this study, it can be concluded that if insects are used as feed materials, the maximum limits of these elements in complete feed should be revised per insect species.

Miserable minority: emotional risk factors that influence the outcome of a mild traumatic brain injury.

Emotional risk factors are explored in four case studies, each of whom had sustained a mild traumatic brain injury (MTBI). Selected pre-existing personality traits that compounded the symptom presentation included over-achievement, dependency, grandiosity and borderline personality traits. Premorbid risk factors are described and their influence on co-morbid and post-morbid difficulties is discussed. We also touched upon the therapeutic issues involved in our cases. General treatment considerations are highlighted for dealing with grandiosity, narcissistic features and borderline traits. Over-achievement and perfectionism are discussed in the context of providing treatment for stress management. Finally, the effect of pre-existing emotional trauma combined with the MTBI is discussed.

The Depressive Experiences Questionnaire: a critical review.

The Depressive Experiences Questionnaire (DEQ; Blatt, D'Afflitti, & Quinlan, 1976) is critically reviewed. First the developmental, object representations theory differentiating depression into anaclitic and introjective subtypes is presented. The DEQ factors of Dependency and Self-Criticism were initially found to be consistent with these clinically meaningful depressive subtypes. Subsequent research has generally demonstrated that these subtypes, at least as measured by the DEQ, do not hold up well in clinical populations. Furthermore, the validity of the developmental theory of these subtypes is weak. We suggest that more internally consistent and distinct factors should be developed from clinical populations because of their potential clinical usefulness.