Assessing the Mental Model State of Emergency Responders in the Context of Radiological Dispersal Device (RDD) Incidents: A Multi-state Study.

ABSTRACT: Hazardous Materials (HAZMAT) Technicians' notions of mental model, or cognitive representations of their understanding and beliefs regarding Radiological Dispersal Devices (RDDs) incidents, have not been previously explored. A prior study developed an Expected Mental Model State (EMMS) framework specific to RDD incident response for HAZMAT technicians. The work herein presents the development of a derivative of this framework, the EMMS Diagnostic Matrix, to evaluate the actual Mental Model State (MMS) of HAZMAT technicians in the context of RDD incidents. The EMMS Diagnostic Matrix was administered via a survey and simulation activity in four U.S. states representing the Northeast, West, South, and Midwest regions. Data were collected and coded using grounded theory methodology. Reflexive thematic analysis was employed to identify themes across related areas where the notions of mental model for the HAZMAT technician responders' actual MMS differed from the EMMS. The analysis of the collected data revealed four significant themes representing incomplete notions of the mental model spanning various EMMS conceptual domains: Overestimation of Radiation Dose and Health Effects, indicating misunderstandings about the health impacts of radiation exposure, Acute Radiation Syndrome (ARS), particularly in the lower range of radiation doses; Overreliance on Responder Protection [personal protective equipment (PPE)/self-contained breathing apparatus (SCBA)], highlighting gaps in understanding radiation principles and radioactive material dispersal properties from a radiological dispersal device; Misunderstanding Radiation Detection and Units, signifying confusion about radiation units and differentiation between dose rate and accumulated dose; and Incomplete Understanding of Radiation Characteristics and Dispersal Properties, outlining a limited grasp of inhalation risks from radiation and the dispersal traits of a radiological dispersal device. The interconnectedness of these technical misunderstandings can guide the development of a strategic plan to evaluate and modify existing training, aiming at these specific themes to improve the efficiency of HAZMAT technicians in emergency situations and to identify areas for further research.

Rapid benefits in older age from transition to whole food diet regardless of protein source or fat to carbohydrate ratio: Arandomised control trial.

Plant-based diets reduces the risk of chronic conditions. The interaction between protein source and other macronutrients-fat (F) and carbohydrate (C)-has yet to be investigated. The aim was to assess the main and interactive effects of protein-source (plant vs. animal) and F:C (high or low) and the transition from an Australian diet to a whole food diet on various health markers in older individuals. This single-blinded, parallel, randomised experimental trial used a 2 × 2 factorial design to compare pro-vegetarian (70:30 plant to animal) versus omnivorous (50:50 plant to animal) diets at 14% protein and varying fat-to-carbohydrate ratios (high fat ~40% vs. low fat ~30%) over 4 weeks. Study foods were provided, alcohol consumption was discouraged, and dietary intake was determined through food records. Analysis included both RCT and observational data. Changes in appetite, palatability of diets, and dietary intake were assessed. Body composition, muscle strength, function, gut microbiome, and cardiometabolic health parameters were measured. Data from 113 (of the 128 randomised) individuals aged 65-75 years were analysed. Pro-vegetarian diets reduced diastolic blood pressure, total cholesterol and glucose levels. Moreover, the overall sample exhibited increased short-chain fatty acids and FGF21 levels, as well as improvements in body composition, function, and cardio-metabolic parameters irrespective of dietary treatment. Transitioning to a diet rich in fruit, vegetables, fibre, and moderate protein was associated with improved health markers in older age, with added benefits from pro-vegetarian diets. Further research on long-term effects is needed.

Respiratory acidosis and O2 supply capacity do not affect the acute temperature tolerance of rainbow trout (Oncorhynchus mykiss).

The mechanisms that determine the temperature tolerances of fish are poorly understood, creating barriers to disentangle how additional environmental challenges-such as CO2-induced aquatic acidification and fluctuating oxygen availability-may exacerbate vulnerability to a warming climate and extreme heat events. Here, we explored whether two acute exposures (~0.5 hours or ~72 hours) to increased CO2 impact acute temperature tolerance limits in a freshwater fish, rainbow trout (Oncorhynchus mykiss). We separated the potential effects of acute high CO2 exposure on critical thermal maximum (CTmax), caused via either respiratory acidosis (reduced internal pH) or O2 supply capacity (aerobic scope), by exposing rainbow trout to ~1 kPa CO2 (~1% or 10 000 µatm) in combination with normoxia or hyperoxia (~21 or 42 kPa O2, respectively). In normoxia, acute exposure to high CO2 caused a large acidosis in trout (blood pH decreased by 0.43 units), while a combination of hyperoxia and ~1 kPa CO2 increased the aerobic scope of trout by 28%. Despite large changes in blood pH and aerobic scope between treatments, we observed no impacts on the CTmax of trout. Our results suggest that the mechanisms that determine the maximum temperature tolerance of trout are independent of blood acid-base balance or the capacity to deliver O2 to tissues.

Context-dependent multimodal behaviour in a coral reef fish.

Animals are expected to respond flexibly to changing circumstances, with multimodal signalling providing potential plasticity in social interactions. While numerous studies have documented context-dependent behavioural trade-offs in terrestrial species, far less work has considered such decision-making in fish, especially in natural conditions. Coral reef ecosystems host 25% of all known marine species, making them hotbeds of competition and predation. We conducted experiments with wild Ambon damselfish (Pomacentrus amboinensis) to investigate context-dependent responses to a conspecific intruder; specifically, how nest defence is influenced by an elevated predation risk. We found that nest-defending male Ambon damselfish responded aggressively to a conspecific intruder, spending less time sheltering and more time interacting, as well as signalling both visually and acoustically. In the presence of a model predator compared to a model herbivore, males spent less time interacting with the intruder, with a tendency towards reduced investment in visual displays compensated for by an increase in acoustic signalling instead. We therefore provide ecologically valid evidence that the context experienced by an individual can affect its behavioural responses and multimodal displays towards conspecific threats.

Mice Regulate Dietary Amino Acid Balance and Energy Intake by Selecting between Complementary Protein Sources.

BACKGROUND: A balanced intake of protein and constituent amino acids (AAs) requires adjustments to total food intake (protein leverage [PL]) and food selection to balance deficits and excesses (complementary feeding). We provided mice with choices of casein and whey, 2 protein sources that are complementary in AA balance, across a range of protein concentrations (P%) of digestible energy (DE). OBJECTIVES: We aimed to determine if: 1) PL operates similarly for casein and whey; 2) one protein source is preferred at control P%; 3) the preference changes as P% falls; and 4) AA intakes under control and low P% levels identify AAs that drive changes in protein selection. METHODS: Food intake and plasma fibroblast growth factor-21 (FGF21) concentrations were measured in mice at various P% (P7.5%-P33%). For direct comparisons, defined diets were used in which the protein source was either casein or whey. In food choice studies, mice had access to foods in which both casein and whey were provided at the same P% level at the same time. RESULTS: PL operated at different P% thresholds in casein (13%)- and whey (10%)-based diets, and the magnitude of PL was greater for casein. Although mice preferred casein under control conditions (P23%), a pronounced preference shift to whey occurred as P% fell to P13% and P10%. At low P%, increases in food intake were accompanied by increases in plasma FGF21, a protein hunger signal. Among AAs deficient in casein and enriched in whey, the intake of Cys was the most invariant as P% changed between P23% and P10%, appearing to drive the switch in protein preference. CONCLUSIONS: Mice selected between complementary protein sources, casein and whey, achieving stable total energy intake and regulated intake of AAs as P% varied. Supplementation of low P% casein diets with one whey-enriched AA, Cys, suppressed plasma FGF21 and total food intake.

Macronutrient composition of plant-based diets and breast cancer risk: the E3N prospective cohort study.

PURPOSE: Recent evidence suggests that plant-based diets may reduce the risk of breast cancer (BC). However, the macronutrient composition of plant-based diets and its potential impact on BC risk has not been well explored. This analysis investigated the association of macronutrient composition with BC risk across a spectrum of plant-based diet indexes using a multidimensional approach. DESIGN: This study followed 64,655 participants from the Etude Epidémiologique auprès de femmes de la Mutuelle Générale de l'Education Nationale (E3N) cohort from 1993 to 2014. Diets were evaluated using validated 208-item diet history questionnaires at baseline (1993) and follow-up (2005), to calculate adherence to the overall plant-based diet (PDI), healthful plant-based diet (hPDI), and unhealthful plant-based diet (uPDI). The association of macronutrient composition with BC risk was assessed via generalized additive time-dependent Cox models across different levels of these indexes. Response surfaces were generated to visualize compositional associations at the 25th, 50th, and 75th percentile of each index (low, moderate, and high). RESULTS: A total of 3,932 incident BC cases were identified during the 21-year follow-up. There was a significant association between macronutrient composition and BC risk for hPDI, uPDI, and PDI (all P < 0.001). Akaike information criterion favored the hPDI model for characterizing the association between macronutrients and BC. BC risk was highest for individuals with a lower hPDI score who also consumed a diet containing lower protein (10%), lower carbohydrate (35%), and higher fat (55%). The lowest risk of BC was observed in those with higher hPDI scores with the lowest intake of protein (10%). At higher PDI and uPDI, diets containing higher protein (30%) and fat (45%) had the highest BC risk. CONCLUSION: These results demonstrate a complex relationship between macronutrient composition, plant-based diet quality, and BC risk. Further research is needed to examine specific foods that may be driving these associations. REGISTRY: The protocol is registered at clinicaltrials.gov as NCT03285230.

Paternal dietary macronutrient balance and energy intake drive metabolic and behavioral differences among offspring.

Paternal diet can influence the phenotype of the next generation, yet, the dietary components inducing specific responses in the offspring are not identified. Here, we use the Nutritional Geometry Framework to determine the effects of pre-conception paternal dietary macronutrient balance on offspring metabolic and behavioral traits in mice. Ten isocaloric diets varying in the relative proportion of protein, fats, and carbohydrates are fed to male mice prior to mating. Dams and offspring are fed standard chow and never exposed to treatment diets. Body fat in female offspring is positively associated with the paternal consumption of fat, while in male offspring, an anxiety-like phenotype is associated to paternal diets low in protein and high in carbohydrates. Our study uncovers that the nature and the magnitude of paternal effects are driven by interactions between macronutrient balance and energy intake and are not solely the result of over- or undernutrition.

The effects of paternal dietary fat versus sugar on offspring body composition and anxiety-related behavior.

Increasing evidence suggests that the pre-conception parental environment has long-term consequences for offspring health and disease susceptibility. Though much of the work in this field concentrates on maternal influences, there is growing understanding that fathers also play a significant role in affecting offspring phenotypes. In this study, we investigate effects of altering the proportion of dietary fats and carbohydrates on paternal and offspring body composition and anxiety-related behavior in C57Bl/6-JArc mice. We show that in an isocaloric context, greater dietary fat increased body fat and reduced anxiety-like behavior of studs, whereas increased dietary sucrose had no significant effect. These dietary effects were not reflected in offspring traits, rather, we found sex-specific effects that differed between offspring body composition and behavioral traits. This finding is consistent with past paternal effect studies, where transgenerational effects have been shown to be more prominent in one sex over the other. Here, male offspring of fathers fed high-fat diets were heavier at 10 weeks of age due to increased lean body mass, whereas paternal diet had no significant effect on female offspring body fat or lean mass. In contrast, paternal dietary sugar appeared to have the strongest effects on male offspring behavior, with male offspring of high-sucrose fathers spending less time in the closed arms of the elevated plus maze. Both high-fat and high-sugar paternal diets were found to reduce anxiety-like behavior of female offspring, although this effect was only evident when offspring were fed a control diet. This study provides new understanding of the ways in which diet can shape the behavior of fathers and their offspring and contribute to the development of dietary guidelines to improve obesity and mental health conditions, such as anxiety.

Maternal macronutrient intake effects on offspring macronutrient targets and metabolism.

OBJECTIVE: Exposure in utero to maternal diet can program offspring health and susceptibility to disease. Using C57BL6/JArc mice, we investigated how maternal dietary protein to carbohydrate balance influences male and female offspring appetite and metabolic health. METHODS: Dams were placed on either a low-protein (LP) or high-protein (HP) diet. Male and female offspring were placed on a food choice experiment post weaning and were then constrained to either a standard diet or Western diet. Food intake, body weight, and composition were measured, and various metabolic tests were performed at different timepoints. RESULTS: Offspring from mothers fed HP diets selected a higher protein intake and had increased body weight in early life relative to offspring from LP diet-fed dams. As predicted by protein leverage theory, higher protein intake targets led to increased food intake when offspring were placed on no-choice diets, resulting in greater body weight and fat mass. The combination of an HP maternal diet and a Western diet further exacerbated this obesity phenotype and led to long-term consequences for body composition and metabolism. CONCLUSIONS: This work could help explain the association between elevated protein intake in humans during early life and increased risk of obesity in childhood and later life.

Metagenomics for Pathogen Detection During a Mass Mortality Event in Songbirds.

Mass mortality events in wildlife can be indications of an emerging infectious disease. During the spring and summer of 2021, hundreds of dead passerines were reported across the eastern US. Birds exhibited a range of clinical signs including swollen conjunctiva, ocular discharge, ataxia, and nystagmus. As part of the diagnostic investigation, high-throughput metagenomic next-generation sequencing was performed across three molecular laboratories on samples from affected birds. Many potentially pathogenic microbes were detected, with bacteria forming the largest proportion; however, no singular agent was consistently identified, with many of the detected microbes also found in unaffected (control) birds and thus considered to be subclinical infections. Congruent results across laboratories have helped drive further investigation into alternative causes, including environmental contaminants and nutritional deficiencies. This work highlights the utility of metagenomic approaches in investigations of emerging diseases and provides a framework for future wildlife mortality events.

Dietary macronutrient composition impacts gene regulation in adipose tissue.

Diet is a key lifestyle component that influences metabolic health through several factors, including total energy intake and macronutrient composition. While the impact of caloric intake on gene expression and physiological phenomena in various tissues is well described, the influence of dietary macronutrient composition on these parameters is less well studied. Here, we use the Nutritional Geometry framework to investigate the role of macronutrient composition on metabolic function and gene regulation in adipose tissue. Using ten isocaloric diets that vary systematically in their proportion of energy from fat, protein, and carbohydrates, we find that gene expression and splicing are highly responsive to macronutrient composition, with distinct sets of genes regulated by different macronutrient interactions. Specifically, the expression of many genes associated with Bardet-Biedl syndrome is responsive to dietary fat content. Splicing and expression changes occur in largely separate gene sets, highlighting distinct mechanisms by which dietary composition influences the transcriptome and emphasizing the importance of considering splicing changes to more fully capture the gene regulation response to environmental changes such as diet. Our study provides insight into the gene regulation plasticity of adipose tissue in response to macronutrient composition, beyond the already well-characterized response to caloric intake.

Life-History Trade-Offs in Drosophila: Flies Select a Diet to Maximize Reproduction at the Expense of Lifespan.

Macronutrient intake impacts physiology, behavior, and gene expression in a wide range of organisms. We used the response surface methodology to compare how life history traits, lifespan, and reproduction differ as a function of protein and carbohydrate intakes under choice and no-choice feeding regimens in the fruit fly, Drosophila melanogaster. We found that when offered a choice of nutritionally complementary foods mated female flies regulated toward a protein to carbohydrate ratio (P:C) that was associated with shortened lifespan and maximal egg production when compared to response surfaces derived from flies fed 1 of a range of fixed diets differing in P:C (no-choice regimen). This difference in lifespan between choice and no-choice feeding was not seen in males or virgin flies, reflecting the fact that increased protein intake is triggered by mating to support egg production. However, whereas in mated females a higher P:C intake was associated with greater egg production under both choice and no-choice feeding, contrary to expectations, choice-fed mated flies laid fewer eggs than no-choice flies on equivalent macronutrient intakes, perhaps reflecting that they had to ingest twice the volume of food to attain an equivalent intake of nutrients than no-choice flies on a diet of equivalent P:C ratio.

Fungal infection alters collective nutritional intake of ant colonies.

In animals, parasitic infections impose significant fitness costs.1,2,3,4,5,6 Infected animals can alter their feeding behavior to resist infection,7,8,9,10,11,12 but parasites can manipulate animal foraging behavior to their own benefits.13,14,15,16 How nutrition influences host-parasite interactions is not well understood, as studies have mainly focused on the host and less on the parasite.9,12,17,18,19,20,21,22,23 We used the nutritional geometry framework24 to investigate the role of amino acids (AA) and carbohydrates (C) in a host-parasite system: the Argentine ant, Linepithema humile, and the entomopathogenic fungus, Metarhizium brunneum. First, using 18 diets varying in AA:C composition, we established that the fungus performed best on the high-amino-acid diet 1:4. Second, we found that the fungus reached this optimal diet when given various diet pairings, revealing its ability to cope with nutritional challenges. Third, we showed that the optimal fungal diet reduced the lifespan of healthy ants when compared with a high-carbohydrate diet but had no effect on infected ants. Fourth, we revealed that infected ant colonies, given a choice between the optimal fungal diet and a high-carbohydrate diet, chose the optimal fungal diet, whereas healthy colonies avoided it. Lastly, by disentangling fungal infection from host immune response, we demonstrated that infected ants foraged on the optimal fungal diet in response to immune activation and not as a result of parasite manipulation. Therefore, we revealed that infected ant colonies chose a diet that is costly for survival in the long term but beneficial in the short term-a form of collective self-medication.

The Relationship between Dietary Macronutrient Composition and Telomere Length Among US Adults.

The role of dietary macronutrients and energy intake in the aging process has been well-established. However, previous research has mainly focused on the association between leukocyte telomere length (LTL) and individual macronutrients, while the effects of macronutrient composition on LTL remain unclear. This cross-sectional analysis involved 4130 US adults (44.8 ± 17.0 years; 51% female) from the National Health and Nutrition Examination Survey during 1999-2002. A single 24-h dietary recall is used to collect dietary data. The relationship between dietary macronutrient composition and LTL is examined using three-dimensional generalized additive models. After adjustment for age, sex, ethnicity, education, physical activity, BMI, and dietary quality, a three-dimensional association of macronutrient composition with LTL (P = 0.02) is revealed. Diets lower in protein (5-10%), higher in carbohydrates (75%), and lower in fat (15-20%) are associated with the longest LTL corresponding to 7.7 years of slower biological aging. Diets lowest in protein (5%) and carbohydrate (40%), while highest in dietary fat (55%) are associated with the shortest LTL, corresponding to accelerated biological aging of 4.4 years. The associations appeared magnified with higher energy intake. These findings support a complex relationship between dietary macronutrients and biological aging independent of diet quality.

Anisotropic interaction and motion states of locusts in a hopper band.

Swarming locusts present a quintessential example of animal collective motion. Juvenile locusts march and hop across the ground in coordinated groups called hopper bands. Composed of up to millions of insects, hopper bands exhibit aligned motion and various collective structures. These groups are well-documented in the field, but the individual insects themselves are typically studied in much smaller groups in laboratory experiments. We present, to our knowledge, the first trajectory data that detail the movement of individual locusts within a hopper band in a natural setting. Using automated video tracking, we derive our data from footage of four distinct hopper bands of the Australian plague locust, Chortoicetes terminifera. We reconstruct nearly 200 000 individual trajectories composed of over 3.3 million locust positions. We classify these data into three motion states: stationary, walking and hopping. Distributions of relative neighbour positions reveal anisotropies that depend on motion state. Stationary locusts have high-density areas distributed around them apparently at random. Walking locusts have a low-density area in front of them. Hopping locusts have low-density areas in front and behind them. Our results suggest novel insect interactions, namely that locusts change their motion to avoid colliding with neighbours in front of them.

Low-Fat, High-Carbohydrate Diets Reduce Body Weight and Sperm Count but Increase Sperm Motility in Mice.

BACKGROUND: Male reproduction is impacted by both over- and under-nutrition, demonstrated by animal studies using high-fat and low-protein dietary interventions. Little is known about the impacts of low-fat, high-carb diets and types of dietary carbohydrates on sperm traits. OBJECTIVES: Using a nutritional geometry approach, we investigated the effects of partially or completely substituting glucose for fructose in isocaloric diets containing either 10%, 20%, or 30% fat (by energy) on sperm traits in mice. METHODS: Male C57BL/6J mice were fed 1 of 15 experimental diets for 18 wk starting from 8 wk of age. Reproductive organs were then harvested, and sperm concentration, motility, and velocity were measured using Computer-Assisted Sperm Analysis. RESULTS: Increasing dietary fat from 10% to 30% while maintaining energy density at 14.3 kJ/g and protein content at 20% resulted in increased body weight and sperm production but reduced the percentage of motile sperm. Body weight and seminal vesicle weight were maximized on diets containing a 50:50 mix of fructose and glucose, but carbohydrate type had few significant impacts on epididymal sperm traits. CONCLUSIONS: The opposing impacts of dietary fat on mouse sperm quantity and quality observed suggest that male fertility may not be optimized by a single diet; rather, context-specific dietary guidelines targeted to specific concerns in semen quality may prove useful in treating male infertility.

Evidence for protein leverage on total energy intake, but not body mass index, in a large cohort of older adults.

BACKGROUND: Protein leverage (PL) is the phenomenon of consuming food until absolute intake of protein approaches a 'target value', such that total energy intake (TEI) varies passively with the ratio of protein: non-protein energy (fat + carbohydrate) in the diet. The PL hypothesis (PLH) suggests that the dilution of protein in energy-dense foods, particularly those rich in carbohydrates and fats, combines with protein leverage to contribute to the global obesity epidemic. Evidence for PL has been reported in younger adults, children and adolescents. This study aimed to test for PL and the protein leverage hypothesis (PLH) in a cohort of older adults. METHODS: We conducted a retrospective analysis of dietary intake in a cohort of 1699 community-dwelling older adults aged 67-84 years from the NuAge cohort. We computed TEI and the energy contribution (EC) from each macronutrient. The strength of leverage of macronutrients was assessed through power functions ( TEI = µ * EC L ). Body mass index (BMI) was calculated, and mixture models were fitted to predict TEI and BMI from macronutrients' ECs. RESULTS: In this cohort of older adults, 53% of individuals had obesity and 1.5% had severe cases. The mean TEI was 7673 kJ and macronutrients' ECs were 50.4%, 33.2% and 16.4%, respectively for carbohydrates, fat, and protein. There was a strong negative association (L = -0.37; p < 0.001) between the protein EC and TEI. Each percent of energy intake from protein reduced TEI by 77 kJ on average, ceteris paribus. However, BMI was unassociated with TEI in this cohort. CONCLUSIONS: Findings indicate clear evidence for PL on TEI, but not on BMI, likely because of aging, body composition, sarcopenia, or protein wasting.

Toward reconciling the roles of FGF21 in protein appetite, sweet preference, and energy expenditure.

Fibroblast growth factor 21 (FGF21), an endocrine signal robustly increased by protein restriction independently of an animal's energy status, exerts profound effects on feeding behavior and metabolism. Here, we demonstrate that considering the nutritional contexts within which FGF21 is elevated can help reconcile current controversies over its roles in mediating macronutrient preference, food intake, and energy expenditure. We show that FGF21 is primarily a driver of increased protein intake in mice and that the effect of FGF21 on sweet preference depends on the carbohydrate balance of the animal. Under no-choice feeding, FGF21 infusion either increased or decreased energy expenditure depending on whether the animal was fed a high- or low-energy diet, respectively. We show that while the role of FGF21 in mediating feeding behavior is complex, its role in promoting protein appetite is robust and that the effects on sweet preference and energy expenditure are macronutrient-state-dependent effects of FGF21.