Sleep and the gut microbiota in preschool aged children

Sleep plays a significant role in the mental and physical development of children. Emerging evidence in animals and human adults indicates a relationship between sleep and the gut microbiota; however, it is unclear whether the sleep of preschoolers during a key developmental period, associates with features of their gut microbiota. The objective of this study was to assess the relationship between sleep and gut microbiota in preschool aged children (4.37 ±0.48 years, n=143). Sleep measures included total nighttime sleep (TST), sleep efficiency (SE), and wake-time after sleep onset (WASO) assessed using actigraphy. Beta-diversity differences between children with low and high TST (p =0.048) suggest gut microbiota community differences. Particularly, relative abundance of Bifidobacterium was higher in the high TST group and Bacteroides, was higher in children who had higher SE and low WASO (LDA score >2). In contrast, some Lachnospiraceae members including Blautia and Coprococcus 1 were associated with shorter nighttime sleep duration and less efficiency, respectively. We also found a group of faecal metabolites, including specific neuroactive compounds and immunomodulating metabolites were associated with greater sleep efficiency and less time awake at night. Notably, tryptophan and its metabolizing products were higher in children who had higher SE or lower WASO (LDA score >2); concentration of propionate was higher in children with lower WASO (p =0.036). Overall, our results reveal a novel association between sleep and gut microbiota in preschool aged children. Longer nighttime sleep and greater sleep efficiency were associated with specific commensal bacteria that may regulate sleep through modulating neurotransmitter metabolism and the immune system.

Telomerase as a possible key to bypass the cost of reproduction effect

Telomerase activity and telomere restoration in certain somatic cells of human adults maintain the proliferative capacity of these cells and contribute to their regenerative potential, and telomerase activity and telomere length are commonly considered lifespan predictors. Eusocial insects provide excellent model systems for aging research based on their extraordinary caste-related lifespan differences that contradict the typical fecundity/lifespan trade-off. In agreement with the common presumption, telomerase activity is upregulated in the reproductive, long-lived individuals of eusocial insects such as queens and kings, proposing that telomerase activity acts as a key factor in their extended longevity. But, as documented by the presence of telomerase in somatic tissues of numerous invertebrate and vertebrate species, the connection between telomerase activity and the predicted lifespan is not clear. Here, I ask whether somatic telomerase activity in eusocial reproductives may serve its non-canonical function to protect its individuals against the exacerbated metabolic stress upon reproduction and be a reflection of a more common phenomenon among species. I propose a hypothesis that the presence of telomerase activity in somatic cells reflects a different reproduction strategy of the species.

Brain intrinsic connection patterns underlying tool processing in human adults are present in neonates and not in macaques

Tool understanding and use are supported by a dedicated left-lateralized, intrinsically connected network in the human adult brain. To examine this network's phylogenic and ontogenetic origins, we compared resting-state functional connectivity (rsFC) among regions subserving tool processing in human adults to rsFC among homologous regions in human neonates and macaque monkeys (adolescent and mature). These homologous regions formed an intrinsic network in human neonates, but not in macaques. Network topological patterns were highly similar between human adults and neonates, and significantly less so between humans and macaques. The premotor-parietal rsFC had most significant contribution to the formation of the neonate tool network. These results suggest that an intrinsic brain network potentially supporting tool processing exists in the human brain prior to individual tool use experiences, and that the premotor-parietal functional connection in particular offers a brain basis for complex tool behaviors specific to humans.

Association Between Adipose Tissue Characteristics and Metabolic Flexibility in Humans: A Systematic Review

Adipose tissue total amount, distribution, and phenotype influence metabolic health. This may be partially mediated by the metabolic effects that these adipose tissue characteristics exert on the nearby and distant tissues. Thus, adipose tissue may influence the capacity of cells, tissues, and the organism to adapt fuel oxidation to fuel availability, i.e., their metabolic flexibility (MetF). Our aim was to systematically review the evidence for an association between adipose tissue characteristics and MetF in response to metabolic challenges in human adults. We searched in PubMed (last search on September 4, 2021) for reports that measured adipose tissue characteristics (total amount, distribution, and phenotype) and MetF in response to metabolic challenges (as a change in respiratory quotient) in humans aged 18 to <65 years. Any study design was considered, and the risk of bias was assessed with a checklist for randomized and non-randomized studies. From 880 records identified, 22 remained for the analysis, 10 of them measured MetF in response to glucose plus insulin stimulation, nine in response to dietary challenges, and four in response to other challenges. Our main findings were that: (a) MetF to glucose plus insulin stimulation seems inversely associated with adipose tissue total amount, waist circumference, and visceral adipose tissue; and (b) MetF to dietary challenges does not seem associated with adipose tissue total amount or distribution. In conclusion, evidence suggests that adipose tissue may directly or indirectly influence MetF to glucose plus insulin stimulation, an effect probably explained by skeletal muscle insulin sensitivity.Systematic Review Registration: PROSPERO [CRD42020167810].

Effects of Crowd Size, Composition, and Noise Level On Pool Use in a Mixed-Species Penguin Colony

Studies on how visitors affect penguins in human care report a mixture of negative, neutral, and positive impacts on behavior and physiology. Swimming is a highly motivated behavior that may promote positive welfare in penguins. We investigated how visitor crowd size, composition, and noise levels impact pool use in a mixed-species colony housing king (Aptenodytes patagonicus; n = 20), gentoo (Pygoscelis papua; n = 14), and southern rockhopper (Eudyptes chrysocome; n = 24) penguins. We used video and sound loggers to record if penguins were on land or in water, the number of human adults and children present, and noise levels using 5-minute scan samples from 09:00-15:00 over 36 continuous days. Data were analyzed using linear mixed models with proportion of penguins in the water as the dependent variable and crowd size, composition, and noise levels in A-weighted (dBA) and C-weighted (dBC) scales as independent variables. Crowd size was positively associated with pool use in gentoo penguins. Crowd composition did not predict pool use in any species. Noise levels in dBA, which is adjusted to the higher frequencies of human hearing, positively predicted pool use in southern rockhopper penguins. Noise levels in dBC, which captures lower frequencies, did not predict pool use in any species. No evidence of negative visitor effects was observed. Instead, these results suggest visitors are a neutral stimulus to king penguins and may be enriching to gentoo and southern rockhopper penguins.

The latest research on coconut oil and human health

A meta-analysis of clinical trials comparing the effects of coconut oil consumption with other fats focused only on controlled clinical trials performed on human adults with a duration exceeding two weeks (long enough to let blood lipid concentrations stabilize).coconut oil consumption significantly increased total cholesterol, LDL-cholesterol, and HDL-cholesterol concentrations compared with non-tropical vegetable oils and significantly increased total cholesterol and LDL-cholesterol concentrations compared with palm oil.

Morphometrical observation on the left atrium in human adults

Aim. To determine the left atrial dimensions, their ratios and relationships that characterize anatomy for left atrium structure in the normal human adult using the model of the atrial end-diastolic phase. Methods. We studied 54 heart specimens of subjects aged 3588 years who died from non-cardiac causes. The atrial end-diastolic phase was modeled by filling a specimen fixed in 1% formalin with liquid silicone. After silicone hardened, we performed morphometric measurements by a caliper. The data were processed by using a cluster, correlation and variance analysis. For pairwise comparison, we used the MannWhitney U-test or a two-sided t-test. Results. The article presents mean, standard deviation, median, 25th percentile and 75th percentile and coefficients of variation for the length, width and sagittal size of the left atrium, as well as the values of the distances between the pulmonary vein orifices, which characterize the dimensions of the left atrium posterior wall. Based on the left atrial size differences and their ratios, the specimens were divided into three clusters. The first (n1=23) and second clusters (n2=10) were represented by hearts with a cubic atrium; the second group differed from the first in the larger size of the left atrium. The third cluster (n3=21) included the hearts in which the largest left atrium size was the width, so the shape of the atria resembled a parallelepiped. The typical number of the pulmonary vein ostia we found in 91% of the specimens. The posterior wall of the left atrium, with a common number and topography of the ostia, were rectangle or an unequal trapezium in shape. We analyzed correlations between the sizes of the heart, left atrium and its posterior wall. We concretized the conceptual apparatus concerning the nomenclature and terminology of the left atrium anatomical structures. Conclusion. Based on the size ratio, two shape variations of the left atrium body can be identified: cubic or parallelepiped; cubic atria can be divided into large and small; the co-directional dimensions of the left atrial body and its posterior wall showed the strongest correlations.

Human allergy to cats: A review of the impact on cat ownership and relinquishment

Practical relevance: Cats have become increasingly common as companion animals, and in many countries their popularity now exceeds that of dogs. At the same time, human allergies (including allergy to cats) have been increasing and it has been estimated that globally up to 10-20% of human adults are sensitised to cats. Aim: This review summarises the available published data on how human allergy to cats affects cat ownership and considers the implications of the findings on the wider human-cat bond and how adverse effects can be minimised. Evidence base: Online databases were searched for all original studies up to December 2020 that had quantified the impact of human allergy to cats on ownership or relinquishment. Objective quantifiable data appeared to fall into three broad outcomes - (1) choosing to avoid cat ownership; (2) relinquishment of owned cats; and (3) return of cats after acquisition from a rehoming centre. The data retrieved on these topics are the focus of this review. In some studies, data from cats and dogs were combined and these have also been included in the review.

Behavioral gain following isolation of attention

Stable sensory perception is achieved through balanced excitatory-inhibitory interactions of lateralized sensory processing. In real world experience, sensory processing is rarely equal across lateralized processing regions, resulting in continuous rebalancing. Using lateralized attention as a case study, we predicted rebalancing lateralized processing following prolonged spatial attention imbalance could cause a gain in attention in the opposite direction. In neurotypical human adults, we isolated covert attention to one visual field with a 30-min attention-demanding task and found an increase in attention in the opposite visual field after manipulation. We suggest a gain in lateralized attention in the previously unattended visual field is due to an overshoot through attention rebalancing. The offline post-manipulation effect is suggestive of long-term potentiation affecting behavior. Our finding of visual field specific attention increase could be critical for the development of clinical rehabilitation for patients with a unilateral lesion and lateralized attention deficits. This proof-of-concept study initiates the examination of overshoot following the release of imbalance in other lateralized control and sensory domains, important in our basic understanding of lateralized processing.

A long time ago, in a galaxy far, far away: How temporal are episodic contents?

A prominent feature of mental event (i.e. ‘episodic’) simulations is their temporality: human adults can generate episodic representations directed towards the past or the future. The ability to entertain event representations with different temporal orientations allows these representations to play various cognitive roles. Here, we investigated how the temporal orientation of imagined events relates to the contents (i.e. ‘what is happening’) of these events. Is the temporal orientation of an episode part of its contents? Or are the processes for assigning temporality to an event representation distinct from those generating its contents? In three experiments (N = 360), we asked participants to generate and later recall a series of imagined events differing in (1) location (indoors vs. outdoors), (2) time of day (daytime vs. nighttime), (3) temporal orientation (past vs. future), and (4) weekday (Monday vs. Friday). We then tested to what extent successful recall of episodic content (i.e. (1) and (2)) would predict recall of temporality and/or weekday information. Results showed that while recall of temporal orientation was predicted by content recall, weekday recall was not. However, temporal orientation was only weakly integrated with episodic contents. This finding suggests that episodic simulations are unlikely to be intrinsically temporal in nature. Instead, similar to other forms of temporal information, temporal orientation might be determined from such contents by reconstructive post-retrieval processes. These results have implications for how the human ability to ‘mentally travel’ in time is cognitively implemented.