adult humans
Recently Published Documents


TOTAL DOCUMENTS

598
(FIVE YEARS 101)

H-INDEX

63
(FIVE YEARS 5)

2022 ◽  
Vol 13 ◽  
Author(s):  
Francisco Javier Fuentealba-Villarroel ◽  
Josué Renner ◽  
Arlete Hilbig ◽  
Oliver J. Bruton ◽  
Alberto A. Rasia-Filho

The human posteromedial cortex (PMC), which includes the precuneus (PC), represents a multimodal brain area implicated in emotion, conscious awareness, spatial cognition, and social behavior. Here, we describe the presence of Nissl-stained elongated spindle-shaped neurons (suggestive of von Economo neurons, VENs) in the cortical layer V of the anterior and central PC of adult humans. The adapted “single-section” Golgi method for postmortem tissue was used to study these neurons close to pyramidal ones in layer V until merging with layer VI polymorphic cells. From three-dimensional (3D) reconstructed images, we describe the cell body, two main longitudinally oriented ascending and descending dendrites as well as the occurrence of spines from proximal to distal segments. The primary dendritic shafts give rise to thin collateral branches with a radial orientation, and pleomorphic spines were observed with a sparse to moderate density along the dendritic length. Other spindle-shaped cells were observed with straight dendritic shafts and rare branches or with an axon emerging from the soma. We discuss the morphology of these cells and those considered VENs in cortical areas forming integrated brain networks for higher-order activities. The presence of spindle-shaped neurons and the current discussion on the morphology of putative VENs address the need for an in-depth neurochemical and transcriptomic characterization of the PC cytoarchitecture. These findings would include these spindle-shaped cells in the synaptic and information processing by the default mode network and for general intelligence in healthy individuals and in neuropsychiatric disorders involving the PC in the context of the PMC functioning.


2021 ◽  
Vol 12 (1) ◽  
pp. 371
Author(s):  
Zahida Guerouah ◽  
Steve Lin ◽  
Vladislav Toronov

A major limitation of near-infrared spectroscopy (NIRS) is its high sensitivity to the scalp and low sensitivity to the brain of adult humans. In the present work we used multi-distance hyperspectral NIRS (hNIRS) to investigate the optimal source-detector distances, wavelength ranges, and analysis techniques to separate cerebral responses to 30 s breath-holds (BHs) from the responses in the superficial tissue layer in healthy adult humans. We observed significant responses to BHs in the scalp hemodynamics. Cerebral responses to BHs were detected in the cytochrome C oxidase redox (rCCO) at 4 cm without using data from the short-distance channel. Using the data from the 1 cm channel in the two-layer regression algorithm showed that cerebral hemodynamic and rCCO responses also occurred at 3 cm. We found that the waveband 700–900 nm was optimal for the detection of cerebral responses to BHs in adults.


2021 ◽  
Author(s):  
Roxanne Hawkins ◽  
Bianca Hatin ◽  
Eszter Révész

Humans are adept at extrapolating emotional information from the facial expressions of other humans but may have difficulties identifying emotions in dogs, compromising both dog and human welfare. Experience with dogs such as through pet ownership, as well as anthropomorphic tendencies such as beliefs in animal minds, may influence interspecies emotional communication, yet little research has investigated these variables. This explorative study examined 122 adult humans’ ability to identify human and dog emotional facial expressions (happiness, fearfulness, anger/aggression) through an online experimental emotion recognition task. Experience with dogs (through current dog ownership and duration of current dog ownership), emotion attribution (through beliefs about animal mind), and demographics were also measured. Results showed that fear and happiness were more easily identified in human faces, whereas aggression was more easily identified in dog faces. Duration of current dog ownership, age, and gender identity did not relate to accuracy scores, but current dog owners were significantly better at identifying happiness in dog faces than non-dog owners. Dog ownership and duration of ownership related to increased beliefs about, and confidence in, the emotional ability of dogs, and a stronger belief in animal sentience was positively correlated with accuracy scores for identifying happiness in dogs. Overall, these explorative findings show that adult humans, particularly current dog owners and those who believe in the emotionality of dogs, can accurately identify some basic emotions in dogs, but may be more skilled at identifying positive than negative emotions. The findings have implications for the prevention of negative human-animal interactions through prevention and intervention strategies that target animal emotionality.


Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2295
Author(s):  
Sebastien Durand ◽  
Justine Dufour ◽  
Antonio Rosas ◽  
Fabio Becce ◽  
Caley Orr

In humans, bipartite scaphoid still does not differentiate clearly from traumatic non-union of the scaphoid. To aid diagnosis, we sought to analyze the main geometrical similarities among bipartite scaphoids from primate species with fused and unfused scaphoid centrales. Four human embryos, four cases of adult humans with bipartite scaphoid, twelve adult specimens of other extant anthropoid primates, and two Neandertal scaphoid specimens were included in this study. Three-dimensional polygon models of the scaphoid and os centrale were generated from CT scan, micro-CT scan, or histological sections. A 3D comparative study of the morphological and morphometrical parameters was performed using the MSC Patran software. The os centrale was smaller than the scaphoid in all specimens and its shape was elongated in the anteroposterior scaphoid direction. The position of the os centrale centroid compared to the scaphoid using direction vectors had a strong orientation along the proximodistal axis in all species. The main morphological feature of bipartite scaphoid was the continuity of the scaphoid from its proximal pole to its tubercule along the anteroposterior axis. In all specimens, if the os centrale was removed, the scaphoid still appeared normal and whole. The bipartite scaphoid in adult humans shares geometrical analogies with monkeys and orangutans, human embryos, and Neandertals. Morphological and morphometrical features identified in this study are useful to differentiate bipartite scaphoid from scaphoid pseudarthrosis. All other criteria suggested in the past lead to misdiagnosis.


2021 ◽  
Vol 9 (4) ◽  
pp. 8109-8115
Author(s):  
Ndiaye M R ◽  
◽  
Mar N B ◽  
Yacouba Garba K ◽  
Ndoye J M N ◽  
...  

Aim: The aim of our study was to perform a morphometric analysis of the mental foramen in senegalese context. Material and method: The study was performed on thirty-nine dry mandibles of adult humans. On these mandibles, the number of mental foramen present and their shape were noted on inspection. The situation of the foramen in relation to the lower teeth was studied according to a methodology already described. The following measurements were made: the distance between the foramen and the other landmarks of the mandible (symphysis, basilar border, posterior border), vertical and horizontal diameters. Results: The number of mental foramina were 39 on the right and 40 on the left: one mandible presented a double foramen on the left. The oval shape was predominant. The most frequent situation was below the second premolar on both sides. The mean distance between the foramen and the mandibular symphysis was 25mm on both sides. The distance between the foramen and the basilar border of the mandible was on average 13mm on the right and 14mm on the left. The distance between the foramen and the posterior border of the mandible was on average 72mm on the right and 73mm on the left. The average vertical diameter was 33mm on the right and 32mm on the left, and the average horizontal diameter was 4mm on both sides. Conclusion: Mental foramen is a constant anatomical structure, found on all the mandibles studied. The results can be superimposed on those described in the majority of studies carried out on the mental foramen. Key words: Mental Foramen, Mandible Anatomy, Morphometry.


2021 ◽  
pp. 002580242110495
Author(s):  
Amy Joy Spies ◽  
Maryna Steyn ◽  
Desiré Brits

The accurate radiological detection of skeletal trauma is crucial for the investigation of blunt force trauma (BFT) cases. The sensitivities of CTs, X-rays and Lodox in identifying BFT fractures and minimum number of impacts in pigs, used as proxies for adult humans, were assessed. Ten human sized pig carcasses were struck with a mallet and scanned, after which the number of fractures and minimum number of impacts detected radiologically were recorded. Pig carcasses were then macerated, and the defleshed, skeletonized remains were considered the gold standard as far as number and location of fractures were concerned. CTs were most sensitive in identifying fractures and impacts in all body regions, with overall sensitivities of 55.4% and 71.5% respectively, while X-rays and Lodox had sensitivities of 25.8% and 29.3% for fractures, and 43.5% and 41.1% for impacts, respectively. All modalities were highly specific for identifying fractures (CT: 99.1%; X-ray: 98.9%; Lodox: 99.4%). CTs should be used to analyze blunt force trauma when a radiological assessment is required, but an examination of the defleshed bones remains the gold standard for the deceased whenever feasible. X-rays and Lodox have limited diagnostic value in these cases and relying on them to detect fractures may compromise the accurate forensic investigation of blunt trauma victims. However, the use of Lodox for initial screening of major trauma is still of value. Sensitivities are generally higher for detecting fractures in pigs compared to piglets, indicating that increased diagnostic value is achieved when imaging pigs compared to piglets.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Yohei Watanabe ◽  
Yuki Saito ◽  
Taeko Hara ◽  
Naoki Tsukuda ◽  
Yoshimi Aiyama-Suzuki ◽  
...  

AbstractDietary carbohydrates impact the composition of the human gut microbiota. However, the relationship between carbohydrate availability for individual bacteria and their growth in the intestinal environment remains unclear. Here, we show that the availability of long-chain xylans (LCX), one of the most abundant dietary fibres in the human diet, promotes the growth of Bifidobacterium pseudocatenulatum in the adult human gut. Genomic and phenotypic analyses revealed that the availability of LCX-derived oligosaccharides is a fundamental feature of B. pseudocatenulatum, and that some but not all strains possessing the endo-1,4-β-xylanase (BpXyn10A) gene grow on LCX by cleaving the xylose backbone. The BpXyn10A gene, likely acquired by horizontal transfer, was incorporated into the gene cluster for LCX-derived oligosaccharide utilisation. Co-culturing with xylanolytic Bacteroides spp. demonstrated that LCX-utilising strains are more competitive than LCX non-utilising strains even when LCX-derived oligosaccharides were supplied. In LCX-rich dietary interventions in adult humans, levels of endogenous B. pseudocatenulatum increased only when BpXyn10A was detected, indicating that LCX availability is a fitness determinant in the human gut. Our findings highlight the enhanced intestinal adaptability of bifidobacteria via polysaccharide utilisation, and provide a cornerstone for systematic manipulation of the intestinal microbiota through dietary intervention using key enzymes that degrade polysaccharide as biomarkers.


2021 ◽  
pp. 169-226
Author(s):  
James Woodward

This chapter explores some empirical results bearing on the descriptive and normative adequacy of different accounts of causal learning and representation. It begins by contrasting associative accounts with accounts that attribute additional structure to causal representation, arguing in favor of the latter. Empirical results supporting the claim that adult humans often reason about causal relationships using interventionist counterfactuals are presented. Contrasts between human and nonhuman primate causal cognition are also discussed, as well as some experiments concerning causal cognition in young children. A proposal about what is involved in having adult human causal representations is presented and some issues about how these might develop over time are explored.


GeroScience ◽  
2021 ◽  
Author(s):  
István Vályi-Nagy ◽  
Zsolt Matula ◽  
Márton Gönczi ◽  
Szabolcs Tasnády ◽  
Gabriella Bekő ◽  
...  

Abstract In the present study, humoral and T cell-mediated immune responses elicited by BBIBP-CorV (inactivated virus) and BNT162b2 (mRNA-based) vaccines against SARS-CoV-2 virus were compared. Convalescent volunteers were also investigated to evaluate adaptive immunity induced by live virus. Although both vaccines induced antibody- and T cell-mediated immune responses, our analysis revealed significant quantitative and qualitative differences between the two types of challenges. The BBIBP-CorV vaccine elicited antireceptor-binding domain (RBD) IgG, as well as anti-spike protein (S) IgG and IgA antibodies in healthy individuals, the levels of which were much lower than after BNT162b2 vaccination but still higher than in the convalescent patients. The cumulative IFNγ-positive T cell response, however, was only twofold higher in participants injected with BNT162b2 compared to those who were primed and boosted with BBIBP-CorV vaccine. Moreover, the inactivated virus vaccine induced T cell response that targets not only the S but also the nucleocapsid (N) and membrane (M) proteins, whereas the mRNA vaccine was able to elicit a much narrower response that targets the S protein epitopes only. Thus, the pattern of BBIBP-CorV-induced T cell response in virus-naive participants was similar to the cell-mediated anti-SARS-CoV-2 response observed in convalescent patients. Based on these data, we can conclude that the BBIBP-CorV inactivated virus vaccine is immunologically effective. However, the duration of BBIBP-CorV-induced integrated, antibody, and T cell-mediated, immune responses needs further investigation.


Sign in / Sign up

Export Citation Format

Share Document