Mitochondrial Dysfunction Plus High-Sugar Diet Provokes a Metabolic Crisis That Inhibits Growth

The Drosophila mutant tko^25t exhibits a deficiency of mitochondrial protein synthesis, leading to a global insufficiency of respiration and oxidative phosphorylation. This entrains an organismal phenotype of developmental delay and sensitivity to seizures induced by mechanical stress. We found that the mutant phenotype is exacerbated in a dose-dependent fashion by high dietary sugar levels. tko^25t larvae were found to exhibit severe metabolic abnormalities that were further accentuated by high-sugar diet. These include elevated pyruvate and lactate, decreased ATP and NADPH. Dietary pyruvate or lactate supplementation phenocopied the effects of high sugar. Based on tissue-specific rescue, the crucial tissue in which this metabolic crisis initiates is the gut. It is accompanied by down-regulation of the apparatus of cytosolic protein synthesis and secretion at both the RNA and post-translational levels, including a novel regulation of S6 kinase at the protein level.     

Voluntary Climate Change Mitigation Actions of Young Adults: A Classification of Mitigators through Latent Class Analysis

Encouraging individuals to take action is important for the overall success of climate change mitigation. Campaigns promoting climate change mitigation could address particular groups of the population on the basis of what kind of mitigation actions the group is already taking. To increase the knowledge of such groups performing similar mitigation actions we conducted a population-based cross-sectional study in Finland. The study population comprised 1623 young adults who returned a self-administered questionnaire (response rate 64%). Our aims were to identify groups of people engaged in similar climate change mitigation actions and to study the gender differences in the grouping. We also determined if socio-demographic characteristics can predict group membership. We performed latent class analysis using 14 mitigation actions as manifest variables. Three classes were identified among men: the Inactive (26%), the Semi-active (63%) and the Active (11%) and two classes among women: the Semi-active (72%) and the Active (28%). The Active among both genders were likely to have mitigated climate change through several actions, such as recycling, using environmentally friendly products, preferring public transport, and conserving energy. The Semi-Active had most probably recycled and preferred public transport because of climate change. The Inactive, a class identified among men only, had very probably done nothing to mitigate climate change. Among males, being single or divorced predicted little involvement in climate change mitigation. Among females, those without tertiary degree and those with annual income €≥16801 were less involved in climate change mitigation. Our results illustrate to what extent young adults are engaged in climate change mitigation, which factors predict little involvement in mitigation and give insight to which segments of the public could be the audiences of targeted mitigation campaigns.     

Post-embryonic photoreceptor development and dark/light adaptation in the spittle bug Philaenus spumarius (L.) (Homoptera, Cercopidae)

The aims of this paper have been to describe (1) the general structure of the compound eye of the spittle bug Philaenus spumarius, (2) the eye's post-embryonic development, (3) photomechanical changes upon dark/light adaptation in the eye, and (4) how leaving the semi-aquatic foam bubble and turning into an adult affects the organization of the eye. Spittle bugs, irrespective of size or sex, possess apposition type compound eyes. The eye's major components (i.e. facet, cornea, cone and rhabdom) grow rather isometrically from the smallest nymph to the adult. Photomechanical changes can occur during both nymphal and adult phases and manifest themselves through pigment granules and mitochondria migrating to and away from the rhabdom, and rhabdom diameters varying with time of day and ambient light level. When a nymph transforms into an adult, its compound eyes’ dorsoventral axes widen, facet diameters increase, facet shapes turn from circular to pentagonal and hexagonal, the cornea thickens and the rhabdoms become thinner. The agile adults, free from the foam that surrounds the nymphs, can be expected to need their vision more than the nymphs, and the changes in eye structure do, indeed, indicate that the adults have superior visual acuity. A thicker cornea in the adults reduces water loss and protects the compound eye from mechanical and light-induced damage: protection given to the nymphs by their foam bubbles.     

Inverted Social Reward: Associations between Psychopathic Traits and Self-Report and Experimental Measures of Social Reward

Individuals with high levels of psychopathic traits tend to undervalue long-term, affiliative relationships, but it remains unclear what motivates them to engage in social interactions at all. Their experience of social reward may provide an important clue. In Study 1 of this paper, a large sample of participants (N = 505) completed a measure of psychopathic traits (Self-Report Psychopathy Scale Short-Form) and a measure of social reward value (Social Reward Questionnaire) to explore what aspects of social reward are associated with psychopathic traits. In Study 2 (N = 110), the same measures were administered to a new group of participants along with two experimental tasks investigating monetary and social reward value. Psychopathic traits were found to be positively correlated with the enjoyment of callous treatment of others and negatively associated with the enjoyment of positive social interactions. This indicates a pattern of ‘inverted’ social reward in which being cruel is enjoyable and being kind is not. Interpersonal psychopathic traits were also positively associated with the difference between mean reaction times (RTs) in the monetary and social experimental reward tasks; individuals with high levels of these traits responded comparatively faster to social than monetary reward. We speculate that this may be because social approval/admiration has particular value for these individuals, who have a tendency to use and manipulate others. Together, these studies provide evidence that the self-serving and cruel social behaviour seen in psychopathy may in part be explained by what these individuals find rewarding.     

I Can't Take My Eyes Off of You: Attentional Allocation to Infant,Child, Adolescent and Adult Faces in Mothers and Non-Mothers

It has been reported previously that infant faces elicit enhanced attentional allocation compared to adult faces in adult women, particularly when these faces are emotional and when the participants are mothers, as compared to non-mothers [1]. However, it remains unclear whether this increased salience of infant faces as compared to adult faces extends to children older than infant age, or whether infant faces have a unique capacity to elicit preferential attentional allocation compared to juvenile or adult faces. Therefore, this study investigated attentional allocation to a variety of different aged faces (infants, pre-adolescent children, adolescents, and adults) in 84 adult women, 39 of whom were mothers. Consistent with previous findings, infant faces were found to elicit greater attentional engagement compared to pre-adolescent, adolescent, or adult faces, particularly when the infants displayed distress; again, this effect was more pronounced in mothers compared to non-mothers. Pre-adolescent child faces were also found to elicit greater attentional engagement compared to adolescent and adult faces, but only when they displayed distress. No preferential attentional allocation was observed for adolescent compared to adult faces. These findings indicate that cues potentially signalling vulnerability, specifically age and sad affect, interact to engage attention. They point to a potentially important mechanism, which helps facilitate caregiving behaviour.     

Promotion of adenoma growth by dietary inulin is associated with increase in cyclin D1 and decrease in adhesion proteins in Min/+ mice mucosa

We have earlier shown that dietary fructo-oligosaccharide inulin enhances adenoma growth in multiple intestinal neoplasia (Min/+) mice. To further explore inulin-induced early biochemical changes in the normal-appearing mucosa, Min/+ mice were fed from the age of 5 weeks to the ages of 8 and 15 weeks a control diet or an inulin-enriched diet (10% w/w). In addition, the wild-type littermates were fed with the same diets until the age of 8 weeks, in order to determine whether similar changes happen both in the wild-type and Min/+ mice. The mucosa without adenomas was collected and fractionated to nuclear, cytosolic and membrane pools. The protein levels of beta-catenin, cyclin D1 and E-cadherin were determined by Western blotting at both time points, and immunohistochemical stainings were done for 8-week-old mice. The promotion of adenoma growth by inulin (week 15, 1.3-fold increase, P=.0004) was associated with accumulation of cytosolic and nuclear beta-catenin, and increased amount of cytosolic cyclin D1 (1.5-fold increase, P=.003) in the normal-appearing mucosa of the Min/+ mice. Furthermore, inulin feeding reduced the membranous pools of beta-catenin and E-cadherin. Also in the wild-type mice the drop in membranous beta-catenin was clear (P=.015), and, moreover, a subset of crypts had enhanced nuclear beta-catenin staining. These data indicate that dietary inulin can already activate in the normal-appearing mucosa beta-catenin signaling, which in the presence of Apc mutation induces adenoma growth and even in the wild-type mice direction of the changes is similar.