Search

Dose-response studies are widely used in toxicology to investigate the potency of a compound. Dose-response data are typically evaluated by using a three or four-parameter log-logistic model that includes the upper and lower limits of the response, steepness of the dose-response curve, and the effective dose ED50. Multiple dose-response experiments are conducted to determine the estimation of these four parameters and time related parameters, requiring the aggregation of estimates of these four parameters from various experiments. In this context, non-linear least squares are used as direct methods, which are easy to operate but fitting dose-response models is complicated and often have convergence problems. An alternative estimation method is the two-step method, in which four parameters are estimated before linear regression is used. Similarly, the meta analysis and longitudinal analysis are also implemented based on the estimation of four parameters in the first step. These methods are compared in both practical actual datasets and simulation. We conclude that the two-step method is a more robust estimation method in the complex situation.

Rejection of specific food textures in young children can be a significant barrier to establishing healthy eating habits. However, the literature on texture preferences in children under seven is sparse, partially due to a lack of suitable test tools for this age range. This study aims to investigate texture preferences in 3 to 6-year-old children and their parents and identify factors that could influence children's preferences. Children (n = 235) completed a forced-choice questionnaire based on pictographic drawings of 14 pairs of foods differing in hardness (hard versus soft) or particle content (with-particle versus no-particle). Parents completed the same questionnaire and provided information on their feeding practices and children's eating behaviors. To assess the questionnaire's validity, children performed a paired preference test using actual food stimuli corresponding to 6 food pairs in the questionnaire. Results showed that children preferred foods without particles, and such preference was associated with food neophobia. Children did not show distinct preferences for foods differing in hardness, but older children preferred soft foods more than younger children. Texture preferences significantly differed between parents and children, with a low concordance between parent–child dyads (49–55 %). Parental restrictive feeding was associated with children's rejection of particles in foods, whereas children's experience with different textures was associated with preferences for foods containing particles. Moreover, the questionnaire showed agreement with children's preferences measured using actual foods, and the validity increased with age. This study demonstrated that young children's texture preferences follow developmental trends and depend on the eating environment.

Ocean acidification is caused by rising atmospheric partial pressure of CO2 (pCO2) and involves a lowering of pH combined with increased concentrations of CO2 and dissolved in organic carbon in ocean waters. Many studies investigated the consequences of these combined changes on marine phytoplankton, yet only few attempted to separate the effects of decreased pH and increased pCO2. Moreover, studies typically target photoautotrophic phytoplankton, while little is known of plastidic protists that depend on the ingestion of plastids from their prey. Therefore, we studied the separate and interactive effects of pH and DIC levels on the plastidic ciliate Mesodinium rubrum, which is known to form red tides in coastal waters worldwide. Also, we tested the effects on their prey, which typically are cryptophytes belonging to the Teleaulax/Plagioslemis/Geminigera species complex. These cryptophytes not only serve as food for the ciliate, but also as a supplier of chloroplasts and prey nuclei. We exposed M. rubrum and the two cryptophyte species, T. acuta, T. amphioxeia to different pH (6.8 - 8) and DIC levels (∼ 6.5 - 26 mg C L-1) and assessed their growth and photosynthetic rates, and cellular chlorophyll a and elemental contents. Our findings did not show consistent significant effects across the ranges in pH and/or DIC, except for M. rubrum, for which growth was negatively affected only by the lowest pH of 6.8 combined with lower DIC concentrations. It thus seems that M. rubrum is largely resilient to changes in pH and DIC, and its blooms may not be strongly impacted by the changes in ocean carbonate chemistry projected for the end of the 21st century.

Methods for measuring food texture preferences in children are based on forced-choice questionnaires where children select their preferred texture within food pairs. However, the validity of these methods has not been well documented. This study aims to develop and validate a questionnaire based on pictographic drawings of 12 pairs of foods differing in hardness or particle content. Children aged 7 to 10 years (n = 97) completed the questionnaire. Three weeks later, a subgroup of these children (n = 75) performed a paired comparison preference test using actual food stimuli corresponding to 6 food pairs in the questionnaire and an acceptance test on two foods varying in the level of hardness (cheese) or particle content (yogurt). Another group of the children (n = 21) was retested with the questionnaire. The average probability of agreement between children's choices in the questionnaire and paired-preference test was 0.67, while the retesting was 0.83. In both assessments, the agreement probability was significantly above the chance level, and there was no significant effect of food pair, age or gender. The questionnaire results revealed differences in preferences for the two textural dimensions. Children showed a lack of a common pattern of hardness preference but a preference for foods without particles. Individual differences in particle preferences were related to food neophobia level, and liking of yogurt varying in the amount of added fruit pieces. The results demonstrated the validity and usefulness of the forced-choice pictographic method to study differences in children's texture preferences.

The growing global population and rising demand for meat increasingly pressures the world's resources. Edible insects are a promising alternative protein source to unsustainable conventional meat. Despite this, disgust and neophobia are cited as significant barriers to the adoption of these novel foods in Western diets. The primary aim of this study was to assess the effects of providing three types of information — the taste, health, and sustainability benefits of entomophagy (i.e. the practice of eating insects) — on the willingness to try and hedonic response to insect-based foods among children. In addition, the differences between insects (buffalo worms and cricket) in unprocessed form and in various food applications were examined. Food disgust sensitivity, food neophobia, willingness to try, familiarity, and hedonic response to insect foods were measured. The implications of the appropriateness (as a food ingredient and to be raised as livestock) of two different insect species on acceptance were also explored. The data were collected through an online questionnaire administered in school classrooms from a sample of Danish children (n = 181). Results showed that communicating information about the benefits of entomophagy did not increase the willingness to try insect foods, irrespective of the type of information. Food neophobia was found to be a strong predictor of willingness to try insect foods, whereas food disgust sensitivity had no effect. There was no correlation between food disgust and food neophobia scores. Furthermore, certain types of insect products were found to be better liked than others (e.g. cookies over falafel). There was a species effect on hedonic response when presented as a whole insect although not when presented as processed products made with insect flour.

Alcohol consumption increases circulating high-density lipoprotein cholesterol (HDL-C), but HDL protein cargo may better reflect HDL function. This study examined the associations between alcohol intake and HDL subspecies containing or lacking apoC3, apoE, and apoJ in a well-phenotyped cohort. We performed a cross-sectional analysis of 2092 Cardiovascular Health Study participants aged 70 or older with HDL subspecies measured in stored specimens from 1998 to 1999. Associations between alcohol intake and apoA1 defined HDL subspecies lacking or containing apoC3, apoE, and apoJ, and circulating levels of total apoA1, apoC3, apoE, and apoJ were examined. HDL subspecies lacking and containing apoC3, apoE, and apoJ were all positively associated with alcohol intake, with ∼1% per additional drink per week or ∼7% per additional drink per day (subspecies without the apolipoproteins, P ≤ 2 × 10−9, subspecies with the apolipoproteins, P ≤ 3 × 10−5). Total apoA1 was also directly associated with alcohol consumption, with a 1% increase per additional drink per week (P = 1 × 10−14). Total apoC3 blood levels were 0.5% higher per additional drink per week (P = 0.01), but the association was driven by a few heavily drinking men. Alcohol intake was positively associated with HDL subspecies lacking and containing apoC3, apoE, or apoJ, and with total plasma apoA1. ApoC3 was directly, albeit not as robustly associated with alcohol intake. HDL protein cargo is crucial for its anti-atherosclerotic functions, but it remains to be determined whether HDL subspecies play a role in the putative association between limited alcohol intake and lower risk of coronary heart disease.

In Sub-Saharan Africa, the cultivation of local crop varieties persists despite a political environment that favours commercial seed system development to address seed and food insecurity. Community seed banks (CSBs) are emergent alternative/complementary development initiatives, yet there remains limited empirical research on their role in farmers’ seed systems. In Malawi, where maize is a sociopolitical currency, we use maize seeds as a means to examine how CSBs may support farmers’ seed systems. Through 60 semi-structured interviews with both CSB members and non-members, we collected quantitative and qualitative data on maize seed access opportunities, farmer preferences, and patterns of seed adoption/discontinuation. Interviews show that while CSBs play a negligible role in farmers’ maize seed supply, they can strengthen seed sharing networks through auxiliary social and economic services. CSB members report higher levels of satisfaction with local maize over commercial maize, suggesting CSBs can expand farmers’ frame of reference through events that encourage exchange and experimentation. Local power dynamics can affect CSB accessibility; initiatives to expand CSB operations must therefore address the inherent exclusivity of CSBs as membership-based institutions. These findings invite future research on CSB viability and the potential of decentralized development interventions to improve farmers’ seed security in Sub-Saharan Africa.

Purpose: We investigated whether hepcidin and erythroferrone (ERFE) could complement the Athlete Biological Passport (ABP) in indirectly detecting a 130 mL packed red blood cells (RBCs) autologous blood transfusion. Endurance performance was evaluated.Methods: Forty-eight healthy men (n = 24) and women (n = 24) participated. Baseline samples were collected weekly followed by randomization to a blood transfusion (BT, n = 24) or control group (CON, n = 24). Only the BT group donated 450 mL whole blood from which 130 mL RBCs was reinfused four weeks later. Blood samples were collected 3, 7, 14, 21 and 28 days after donation, and 3, 6, and 24 hours and 2, 3, and 6 days following reinfusion. In the CON group samples were collected with the same frequency. Endurance performance was evaluated by a 650-kCal time trial (n = 13) before and one and six days after reinfusion.Results: A time×treatment effect existed (P < 0.05) for hepcidin and ERFE. Hepcidin was increased (P < 0.01) ~110 and 89% six and 24 hours after reinfusion. Using an individual approach (99% specificity, e.g. allowing 1:100 false-positive), sensitivities, i.e. true positives, of 30% and 61% was found for hepcidin and ERFE, respectively. For the ABP, the most sensitive marker was Off-hr score ([Hb] (g·L-1) - 60 × √RET%) (P < 0.05) with a maximal sensitivity of ~58% and ~ 9% following donation and reinfusion, respectively. Combining the findings for hepcidin, ERFE and the ABP yielded a sensitivity across all time-points of 83% following reinfusion in BT. Endurance performance increased 24 hours (+6.4%, P < 0.01) and six days following reinfusion (+5.8%, P < 0.01).Conclusions: Hepcidin and ERFE may serve as biomarkers in an anti-doping context following an ergogenic, small-volume blood transfusion.

Apple production across Europe is experiencing major yield losses due to pest damage, and the need for alternative production methods are growing. Ecological infrastructures are important to create resilient production systems and increase functional biodiversity. This study investigated perennial flower strips as a means of promoting natural enemies, thereby reducing infestation by the rosy apple aphid, Dysaphis plantaginea, and fruit damage caused by it. In 2016 and 2017, effects of perennial flower strips were assessed in eight organic apple orchards with and without flower strips. In orchards with flower strips, assessments were done in tree rows at two distances: 1st and 3rd row from the flower strip. Assessments included field samples of arthropods, visual observations of D. plantaginea symptoms and observations of predators, observations of predators directly associated with aphid colonies, and fruit damage. In 2016, significantly more symptoms of D. plantaginea were observed in the 3rd row from the flower strip compared to the 1st row from the flower strip. Both years, more predators were observed in the 1st row from the flower strip than in the 3rd row from the flower strip. In 2017, more predators were observed in orchards with a flower strip than in orchards with no flower strip, and more predators were observed inside the aphid colonies in trees in the 1st row from the flower strip than in the 3rd row from the flower strip. Predator diversity in apple trees was also positively affected by proximity to a flower strip. In conclusion, perennial flower strips consistently promote the occurrence of natural enemies in their proximity, while the effect decreases with distance. The correlation between aphid abundance and predators was not always consistent, likely because the majority of the observed predators were generalists and therefore contributing to the natural regulation of the entire herbivore complex in the apple orchards.