Internal bone architecture in the triquetrum of extant hominids and Homo neanderthalensis

Bones on the radial side of the wrist have dominated research on the evolution and functional anatomy of the hominoid carpus. However, soft and hard tissue structures at the ulnar side of the wrist, such as reduced ulna-triquetrum articulation and the Triangular Fibrocartilage Complex (TFCC), are some of the most conspicuous synapomorphies among hominoids linked to high degrees of ulna-deviation and forearm supination [1,2]. However, there is also notable variation in the bony and soft tissue anatomy of the ulnar wrist among hominoids that affects how loads are transferred from the hand to the forearm but are not clearly understood, in part because the functional morphology of the triquetrum is understudied. Here we investigate for the first time the internal trabecular bone structure of the triquetrum and test the null hypothesis that great apes will exhibit similar distributions of relative trabecular bone volume to total volume (BV/TV) and degree of anisotropy (DA). Using a whole-bone methodology (http://www.dr-pahr.at/medtool/) this study quantifies BV/TV and DA in the triquetrum in Pongo (n=12), Gorilla (n=10), Pan (n= 10) and a temporogeographically diverse sample of modern humans (n=21), in comparison to three Homo neanderthalensis individuals (El Sidron SD-1227, Tabun C1_1-154, and Amud 1). The distribution of BV/TV and DA values are visualised across the entire bone using Paraview (3.89.0). Low DA was identified as values equal to or less than 0.20. High BV/TV was identified as the top 20% of values for that individual’s range. In line with presumed force transfer at the ulna-side wrist in hominoids [2], it is predicted that low DA values will be present at the TFCC insertion site, with high BV/TV at the lunate and hamate articulations. Low DA was observed at the TFCC insertion site in 41% of Pongo, 100% of Gorilla, 90% of Pan, 100% of Homo neanderthalensis, and 76% of Homo sapiens. High BV/TV was observed at the hamate articulation site in 75% of Pongo, 90% of Gorilla, 70% of Pan, 100% of Homo neanderthalensis and 61% of Homo sapiens. High BV/TV was observed at the lunate articulation site in 91% of Pongo, 20% of Gorilla, 0% of Pan, 33% of Homo neanderthalensis, and 0.04% of Homo sapiens. Overall, these results suggest relatively consistent interspecific patterns in the trabecular structure of the triquetrum which contrasts the interspecific variation reported in some previous studies, including the capitate [3]. DA predictions were supported for all species except Pongo, where there was only partial support. Predictions for high BV/TV at the triquetrohamate joint were broadly supported while predictions for high BV/TV at the triquetrolunate had mixed support. This pattern suggests that force transfer between the lunate and triquetrum is lower than that between the hamate and triquetrum. Pongo is the exception to this pattern with 91% exhibiting high BV/TV at the triquetrolunate joint, which, when combined with the DA results, may reflect a less-developed TFCC [2] and a greater reliance on the (relatively large) lunate to support ulna-side force transfer compared with other great apes. Although the Neanderthal triquetrum morphology is primitive relative to H. sapiens [4], all three show a BV/TV and DA pattern most similar to that of modern humans. This suggests a similar force transfer pattern at the ulna-side wrist in Neanderthals despite this primitive morphology. There is considerable debate as to whether Neanderthals utilised the same grip patterns as modern H. sapiens and the ulna-side wrist may shed light on the importance of carpal morphology in predicting force transfer and grip types among hominins

Detecting bone functional adaptation in the capitate of extant hominoids

As a central component of the midcarpal and carpometacarpal joints, the capitate plays a primary role in primate hand biomechanics. Capitate morphology facilitates mobility of the midcarpal joint in suspensory apes, limits extension in knuckle-walking apes, and in humans stabilises the capitometacarpal joint for tool behaviours. Biomechanical loading of the capitate varies across taxa with respect to changes in hand and wrist postures associated with different locomotor and manipulative repertoires. As a metabolically active tissue, internal trabecular bone is known to remodel over the lifetime of an individual, and has the potential to reveal patterns of in vivo loading

Internal bone architecture in the capitate of extant hominids

Due to its central role in wrist function and distinctive morphology, the capitate has been an important element for drawing inferences about fossil hominin locomotor and manipulative capacities [1-3]. However, difficulties in studying the numerous, intricate joints of the wrist have led to disagreement about the functional significance of various aspects of its morphology [1-3]. As internal bone is known to adapt to load experienced during life, its structure may reflect the actual postures and behaviours of an individual [4,5]. To date, it is unclear whether the internal bone of the capitate might reflect differences in hand use among hominids. Furthermore, it is not currently understood how cortical and trabecular bone of carpals interact and adapt to cope with the high load and mechanical demands of suspensory or quadrupedal locomotion. To examine the relationship between internal bone architecture and locomotor behaviour, we test for group differences in bone volume to total volume (BV/TV), degree of anisotropy (DA), and cortical thickness (Ct.Th). Further, we analyse the relative distributions of cortical and trabecular bone to assess whether distribution is similar between the locomotor groups. Using a whole-bone method (http://www.dr-pahr.at/medtool/), BV/TV, DA, and Ct.Th were measured in four extant ape genera (n=69) representing bipedal (Homo), knuckle-walking (Pan, Gorilla) and suspensory (Pongo) locomotion. The capitate was partitioned for separate analysis as the proximal portion forms part of the midcarpal joint, while the distal portion forms part of the carpometacarpal joint [3]. BV/TV was measured twice, quantifying just the trabecular region and then the combined cortical and trabecular region. Mean group differences were examined with a KruskalWallis one-way ANOVA and Pairwise Wilcoxon Rank Sum test. Intraspecific ratios were calculated to facilitate comparison of the bone parameters between the proximal and distal regions of each genus. Parameters differed between the genera across all capitate regions (p=<0.001 for all tests), except distal DA (p= 0.593). Ct.Th was the most important parameter for differentiating locomotor groups as distribution across the bone was distinctly different between the human and non-human apes. Compared to the proximal, the distal cortex was thicker in all genera; a 12% increase was seen inHomo, 52% in Pan, 62% inGorilla and 79% in Pongo. This Ct.Th increase coincides with the attachment sites for several ligaments, and might indicate that tensional strain, which has a lower failure load than compressive strain, has an impact on cortical bone functional adaptation. These intergeneric differences further suggest that the hand of bipedal Homo may not experience a similar magnitude of strain. Trabecular BV/TV was higher in the proximal capitate for all genera suggesting it plays a bigger role in adapting to midcarpal joint load than cortical bone in this region. DA in the distal capitate was not significantly different among the genera. This may indicate that the limited mobility at the distal region results in a similar DA, irrespective of hand use. Homo and Pongo were differentiated from the knuckle-walking taxa by having higher DA in the proximal capitate, which was unexpected given our assumption of more variable wrist postures than that of knuckle-walking apes. Results of this study indicate that (1) capitate bone structure is informative for reconstructing hand use and (2) partitioning of ‘cortical’ and ‘trabecular’ regions in carpals (and likely tarsals) may obscure functionally relevant information in the carpus of hominids

In vitro rooting of regenerants of blue poplar

The article presents the research results of the influence of hormonal composition of the culture medium and cultivation duration on regenerants of Populus pruinosa at the stage of rooting in vitro. 98,3±1,7 % of regenerants rooted on MS culture medium with 1,0 mg L−1 IMА during 8 weeks of cultivation.Приведены результаты исследований влияния гормонального состава питательной среды и длительности культивирования на растения-регенеранты тополя сизолистного на этапе укоренения in vitro; 98,3±1,7 % регенерантов укоренялись на питательной среде МС, дополненной 1,0 мг/л ИМК, в течение 8 недель культивирования

Action 3:30R: Results of a cluster randomised feasibility study of a revised teaching assistant-led extracurricular physical activity intervention for 8 to 10 year olds

Many children are not sufficiently physically active. We conducted a cluster-randomised feasibility trial of a revised after-school physical activity (PA) programme delivered by trained teaching assistants (TAs) to assess the potential evidence of promise for increasing moderate-to-vigorous physical activity (MVPA). Participants (n = 335) aged 8–10 years were recruited from 12 primary schools in South West England. Six schools were randomised to receive the intervention and six acted as non-intervention controls. In intervention schools, TAs were trained to deliver an after-school programme for 15 weeks. The difference in mean accelerometer-assessed MVPA between intervention and control schools was assessed at follow-up (T1). The cost of programme delivery was estimated. Two schools did not deliver the intervention, meaning four intervention and six control schools were analysed at T1. There was no evidence for a difference in MVPA at T1 between intervention and control groups. Programme delivery cost was estimated at £2.06 per pupil per session. Existing provision in the 12 schools cost £5.91 per pupil per session. Action 3:30 was feasible to deliver and considerably cheaper than existing after-school provision. No difference in weekday MVPA was observed at T1 between the two groups, thus progression to a full trial is not warranted

Trabecular bone structure of the proximal capitate in extant hominids and fossil hominins with implications for midcarpal joint loading and the dart‐thrower's motion

Objectives: This research examines whether the distribution of trabecular bone in the proximal capitates of extant hominids, as well as several fossil hominin taxa, is associated with the oblique path of the midcarpal joint known as the dart‐thrower's motion (DTM). Materials and Methods: We analyzed proximal capitates from extant (Pongo n = 12; Gorilla n = 11; Pan n = 10; fossil and recent Homo sapiens n = 29) and extinct (Australopithecus sediba n = 2; Homo naledi n = 1; Homo floresiensis n = 2; Neandertals n = 3) hominids using a new canonical holistic morphometric analysis, which quantifies and visualizes the distribution of trabecular bone using relative bone volume as a fraction of total volume (rBV/TV). Results: Homo sapiens and Neandertals had a continuous band of high rBV/TV that extended across the scaphoid, lunate, and hamate subarticular regions, but other fossil hominins and extant great apes did not. A. sediba expressed a distinct combination of human‐like and Pan‐like rBV/TV distribution. Both H. floresiensis and H. naledi had high rBV/TV on the ulnar‐side of the capitate but low rBV/TV on the radial‐side. Conclusion: The proximal capitates of H. sapiens and Neandertals share a distinctive distribution of trabecular bone that suggests that these two species of Homo regularly load(ed) their midcarpal joints along the full extent of the oblique path of the DTM. The observed pattern in A. sediba suggests that human‐like stress at the capito‐scaphoid articular surface was combined with Pan‐like wrist postures, whereas the patterns in H. floresiensis and H. naledi suggest their midcarpal joints were loaded differently from that of H. sapiens and Neandertals

Orbit size and estimated eye size in dinosaurs and other archosaurs and their implications for the evolution of visual capabilities

Vision is one of the most important senses for animals, allowing them to interact with their environment and with further implications for evolutionary histories. However, relevant soft tissues, such as the eye and associated structures, are not preserved in fossil vertebrates, limiting our knowledge of their visual capabilities. Here, we quantified absolute and relative orbit size for 400 species of dinosaurs and other extinct archosaurs using linear measurements of the preserved skeletal elements as a proxy for visual capabilities. Our results demonstrate that the orbit makes up on average 20% of skull size with a strong and consistent correlation across all sampled groups. This trend is largely independent of temporal distribution, species richness, and phylogeny. In fact, relative orbit size is narrowly constrained and did not surpass 45% of skull size, suggesting physiological and functional controls. Estimated eye size was found to be absolutely larger in herbivores, whereas carnivores tended to have smaller eyes absolutely and compared with skull size. Relatively large eyes only occurred in small-bodied species and vice versa. However, eye size alone was not sufficient to discriminate between different activity patterns or to characterize visual capabilities in detail.</p

Pore dynamics and asymmetric cargo loading in an encapsulin nanocompartment

Encapsulins are protein nanocompartments that house various cargo enzymes, including a family of decameric ferritin-like proteins. Here, we study a recombinant Haliangium ochraceum encapsulin:encapsulated ferritin complex using cryo–electron microscopy and hydrogen/deuterium exchange mass spectrometry to gain insight into the structural relationship between the encapsulin shell and its protein cargo. An asymmetric single-particle reconstruction reveals four encapsulated ferritin decamers in a tetrahedral arrangement within the encapsulin nanocompartment. This leads to a symmetry mismatch between the protein cargo and the icosahedral encapsulin shell. The encapsulated ferritin decamers are offset from the interior face of the encapsulin shell. Using hydrogen/deuterium exchange mass spectrometry, we observed the dynamic behavior of the major fivefold pore in the encapsulin shell and show the pore opening via the movement of the encapsulin A-domain. These data will accelerate efforts to engineer the encapsulation of heterologous cargo proteins and to alter the permeability of the encapsulin shell via pore modifications

Do lutein, zeaxanthin, and macular pigment optical density differ with age or age-related maculopathy?

Background and aims Current age-related macular disease (ARMD) treatment includes antioxidant supplementation. Lutein (L) and zeaxanthin (Z) are antioxidants that make up macularpigment within the retina and may reduce the risk of developing ARMD. Ageing and smoking are leading risk factors for developing ARMD. We investigated differences in dietary, supplemental and retinal L and Z, and smoking habits in healthy younger eyes (HY), healthy older eyes (HO) and eyes with an early form of ARMD called age-related maculopathy (ARM). Methods HO, HY and ARM groups were assessed for dietary intakes of L and Z using food diaries. Smoking habits and self-administered quantities of L and Z were obtained via questionnaire. Retinal L and Z levels (macularpigmentopticaldensity, or MPOD) were determined using heterochromatic flicker photometry. Results No significant difference was demonstrated for dietary L and Z intake (?2 = 4.983, p = 0.083) or for MPOD between groups (F = 0.40, p = 0.67). There was a significant difference between the HY (mean ± sd: 1.20 ± 2.99), HO (4.51 ± 7.05) ARM groups (9.15 ± 12.28) for pack years smoked (?2 = 11.61, p = 0.03). Conclusions Our results do not support the theory that ARM develops as a result of L and Z deficiency. Higher pack years smoked may be a factor in disease development. Dietary and supplementary L and Z levels must be obtained when assessing MPOD between groups or over time

The XMM Cluster Survey: X-ray analysis methodology

The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we describe the data processing methodology applied to the 5,776 XMM observations used to construct the current XCS source catalogue. A total of 3,675 > 4-sigma cluster candidates with > 50 background-subtracted X-ray counts are extracted from a total non-overlapping area suitable for cluster searching of 410 deg^2. Of these, 993 candidates are detected with > 300 background-subtracted X-ray photon counts, and we demonstrate that robust temperature measurements can be obtained down to this count limit. We describe in detail the automated pipelines used to perform the spectral and surface brightness fitting for these candidates, as well as to estimate redshifts from the X-ray data alone. A total of 587 (122) X-ray temperatures to a typical accuracy of < 40 (< 10) per cent have been measured to date. We also present the methodology adopted for determining the selection function of the survey, and show that the extended source detection algorithm is robust to a range of cluster morphologies by inserting mock clusters derived from hydrodynamical simulations into real XMM images. These tests show that the simple isothermal beta-profiles is sufficient to capture the essential details of the cluster population detected in the archival XMM observations. The redshift follow-up of the XCS cluster sample is presented in a companion paper, together with a first data release of 503 optically-confirmed clusters.Comment: MNRAS accepted, 45 pages, 38 figures. Our companion paper describing our optical analysis methodology and presenting a first set of confirmed clusters has now been submitted to MNRA