Multi-omics characterization of NIST seafood reference materials and alternative matrix preparations.

The National Institute of Standards and Technology (NIST) has prepared four seafood reference materials (RMs) for use in food safety and nutrition studies: wild-caught and aquacultured salmon (RM 8256 and RM 8257) and wild-caught and aquacultured shrimp (RM 8258 and RM 8259). These materials were characterized using genetic, metabolomic (1H-NMR, nuclear magnetic resonance and LC-HRMS/MS, liquid chromatography high-resolution tandem mass spectrometry), lipidomic, and proteomic methods to explore their use as matrix-matched, multi-omic differential materials for method development towards identifying product source and/or as quality control in untargeted omics studies. The results from experimental replicates were reproducible for each reference material and analytical method, with the most abundant features reported. Additionally, differences between the materials could be detected, where wild-caught and aquacultured seafood could be distinguished using untargeted metabolite, lipid, and protein analyses. Further processing of the fresh-frozen RMs by freeze-drying revealed the freeze-dried seafoods could still be reliably discerned. These results demonstrate the usefulness of these reference materials as tools for omics instrument validation and measurement harmonization in seafood-related studies. Furthermore, their use as differential quality control (QC) materials, regardless of preparation method, may also provide a tool for laboratories to demonstrate proficiency at discriminating between products based on source/species.

Modeling arthropod filiform hair motion using the penalty immersed boundary method.

Crickets are able to sense their surrounding environment through about 2000 filiform hairs located on a pair of abdominal cerci. The mechanism by which the cricket is able to sense a wide range of input signals using these filiform hairs of different length and orientation is of great interest. Most of the previous filiform hair models have focused on a single, rigid hair in an idealized air field. Here, we present a model of the cercus and filiform hairs that are mechanically coupled to the surrounding air, and the model equations are based on the penalty immersed boundary method. The key difference between the penalty immersed boundary method and the traditional immersed boundary method is the addition of forces to account for density differences between the immersed solid (the filiform hairs) and the surrounding fluid (air). The model is validated by comparing the model predictions to experimental results, and then the model is used to examine the interactions between multiple hairs. With multiple hairs, there is little interaction when the hairs are separated by more than 1mm, and, as they move closer, they interact through viscous coupling, which reduces the deflection of the hairs due to the air movement. We also examine the computational scalability of the algorithm and show that the computational costs grow linearly with the number of hairs being modeled.

Neonatal endotoxin exposure influences HPA responsivity and impairs tumor immunity in Fischer 344 rats in adulthood.

Recent research in rodents has demonstrated that exposure to bacterial endotoxin during the neonatal period alters the development of the hypothalamic-pituitary-adrenal axis resulting in hypersecretion of corticosterone after stress-exposure in adulthood. Given the known interactions between glucocorticoids and the immune system it was hypothesized that such alterations may impact on immune outcomes. Fischer 344 rats were treated with endotoxin (50 microg/kg Salmonella enteritidis, i.p.) or the vehicle on postpartum d 1, 3, 5, and 7. In adulthood, animals were subjected to chronic stress (6 x 10 h/d restraint stress), and the effect on resistance to tumor colonization (experiment 1) and natural killer cell activity (experiment 2) was assessed. Experiment 3 assessed corticosterone responses to acute stress in adulthood after neonatal endotoxin or saline treatment. Neonatal endotoxin exposure resulted in a 2-fold increase in tumor colonization (p < 0.001) and a significant impairment in the activity of natural killer cells (p < 0.01), cells critically involved in the surveillance and eradication of tumor cells. Neonatal endotoxin exposure also resulted in a significant decrease in gain weight that persisted into adulthood (p < 0.05), and potentiation of corticosterone responses to acute stress in adulthood (p < 0.05). We conclude that neonatal endotoxin exposure produces long-term changes in the hypothalamic-pituitary-adrenal axis, and has significant long-term effects on immune function, specifically in terms of resistance to tumor colonization in adulthood.

Predicting the extent and stressfulness of problem rumors at home among Army wives of soldiers deployed overseas on a humanitarian mission.

Nearly 500 civilian wives of enlisted soldiers from Fort Drum, New York were surveyed about the extent to which they experienced, as problems, rumors about what was happening in Somalia and when their soldier would return from the Operation Restore Hope deployment to Somalia in 1993. Rumors, as problems, were cited less frequently than loneliness, fears about the soldier's safety, or ignorance of the situation in Somalia but more frequently than problems with communication, finances, or legal issues. The strongest initial predictor of such problems was having communication problems with the soldier. Other significant predictors included length of deployment, soldier's rank, and unit support systems. More frequent use of telephone or regular mail, however, did not appear to reduce such rumors. Stressfulness of rumors appeared to be reduced by good unit leadership, good family support groups, and better emotional adaptability to deployment by spouses, while increased by reliance on surface mail for communication with one's deployed spouse. Subsequent analyses indicated that having fears about the safety of one's soldier or concerns about not knowing what was going on in Somalia were also significantly correlated with rumors as problems. Our results may support hypotheses that rumors serve to fill gaps in official information and justify spouses' anxieties regarding the safety of their deployed soldier.

Characteristics of families of soldiers who return prematurely from overseas deployments: an assessment from Operation Restore Hope (Somalia).

Nearly 500 wives, married to enlisted soldiers who deployed to Somalia for Operation Restore Hope, participated in a postdeployment study in the summer of 1993. About 10% of their husbands had returned early from Somalia for family reasons. Analysis of their wives' reports suggests that early returns were associated most often with childbirth or problematic pregnancies rather than other factors such as inexperience with deployments, negative attitudes towards the military, a lack of support services, or lower coping abilities. However, in hindsight, our results probably reflect compliance with military policy at that time for that deployment, under which pregnancy-related concerns were one of the most legitimate reasons for permitting an early return. The results support sociological theories that highlight the importance of macrosocial factors in influencing the lives of individual families somewhat independently of the microsocial environment of the families.

Factors associated with spouses moving away from their military installation during an overseas deployment.

During overseas deployments, many spouses and families move away from their initial military installation, usually to live with or near relatives. Relatively little has been known about those who move away even though the issue is of importance to the military because its support systems are designed on the assumption that family members are living in proximity to those support systems. The purpose of this research was to describe the characteristics of those who actually moved away during a deployment compared to those who stayed but wanted to leave and to those who stayed. Results generally fit a social exchange model of reasons for moving, staying, or wanting to move but staying. High stress appears to lead to a desire to move but other factors act as barriers or facilitators to actually moving. Military family support did not predict moving away or staying. Implications for military support services are discussed.

The perceived effect of stressors on marital satisfaction among civilian wives of enlisted soldiers deployed to Somalia for Operation Restore Hope.

Nearly 400 spouses of enlisted soldiers who had deployed to Somalia as part of Operation Restore Hope in late 1992 and early 1993 were surveyed in July/August 1993. Their reported post-deployment and retrospective pre-deployment marital satisfaction was predicted as a function of four potentially stressful events or conditions: experiencing a pregnancy during deployment, experiencing loneliness, experiencing the death of a close friend or relative, and/or having problems communicating with one's spouse. Pre-deployment marital stability was used as a control variable. Results from multivariate analyses of variance suggest that the effects of various difficulties during a brief deployment are less stressful, at least in terms of their impact on marital satisfaction, than is often assumed, even for marriages that might be considered "at risk" in terms of low marital stability.

Morphological changes in external and internal feeding structures during the transition phyllosoma-puerulus-juvenile in the Western Rock Lobster (Panulirus cygnus, Decapoda: Palinuridae).

External and internal feeding structures of the pelagic final phyllosoma, the transitional puerulus, and the benthic juvenile Western Rock Lobster, Panulirus cygnus, were studied by means of scanning electron microscopy. The study revealed that the external feeding structures of phyllosomata are well equipped for capture and mastication of food. The foregut, however, is not clearly divided into pyloric and cardiac regions and a gastric mill is absent, although a comb row and gland filter are present. Juveniles, on the other hand, have a well-developed gastric mill and gastric teeth, and a cardiopyloric valve separates the foregut into cardiac and pyloric regions. External mouthparts of juveniles are suitable for mastication of solid food particles and bear numerous setae. In contrast, external mouthparts of pueruli are largely non-setose. Furthermore, although the foregut is differentiated into pyloric and gastric regions and a gland filter and comb row are present, a functional gastric mill is absent during the puerulus stage. Absence of such structures indicates that the puerulus may be a non-feeding stage. It is postulated that absence of (or reduced) feeding may be a response to an increased risk of predation rather than a result of the considerable morphological changes taking place during the transition from a planktonic to a benthic lifestyle, as has been previously proposed. © 1994 Wiley-Liss, Inc.