Anatomy and physiology of bone perfusion in living and foss il birds as assessed by CT-scann ing, microsphere distribution, vascular contrast imaging and foramen measurement

Artery sizes are determined by local blood flow rates, which are driven by local oxygen demand. Arteries that pass through bone foramina, leave the foramina as size representatives of the arteries. Therefore, measuring these foramina sizes without any presence of soft tissue can be a way to estimate blood flow rates. This ‘foramen technique’ can be a useful tool to estimate blood flow rates in ancient animals such as dinosaurs. However, the absolute blood flow passing though foramina needs to be calibrated at this stage, as the size relationship between the foramen and occupying vessel is unclear, especially in foramina with more than one vessel. The major aim of this thesis is to evaluate the foramen-artery size relationship, especially the relationship between the femoral nutrient foramen and nutrient artery, to improve the method of femoral bone blood flow estimation for further foramen studies. Chickens are chosen as the experimental animals. Studying blood flow in birds gives us an opportunity to get insight into blood flow rates in dinosaur bones, as birds are living dinosaurs. The thesis chapters involve several methods to measure foramen sizes or estimate regional bone blood flow rates. Microphotography is chosen to be the most practical foramen measurement method compared to micro-CT and impression material approaches. Chicken femoral bone blood flow rates estimated from infusion of fluorescent microspheres and vascular contrast imaging give similar results. Foramen-artery size relationships are evaluated in chicken femur bones, revealing that the morphologies of femoral nutrient arteries and nutrient foramina can vary among femora. The ‘foramen technique’ is used to estimate femoral bone blood flow in fossil cursorial birds.Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 202

Blood flow rate to the femur of extinct kangaroos implies a higher locomotor intensity compared to living hopping macropods

DATA AVAILABILITY: All data supporting the findings of this study are available within the paper, Online Resource 1 and Online Resource 2.SUPPLEMENTARY MATERIAL 1 : Online Resource 1. Numbers and accession numbers of specimens.SUPPLEMENTARY MATERIAL 2 : Online Resource 2. Measurements of specimens.SUPPLEMENTARY MATERIAL 3 : Online Resource 3. Femur blood flow rate scaling among three extinct kangaroo groups.The stocky skeletons and post-cranial anatomy of many extinct kangaroos indicate that they might have engaged in varied locomotor behaviors, rather than bipedal hopping, as their primary mode of locomotion. This study investigates support for this idea by estimating femoral bone perfusion, which is a correlate of locomotor intensity, in extinct kangaroos compared to living hopping species. Femur blood flow rates can be estimated from the sizes of nutrient foramina on the femur shaft of living and extinct species, without preservation of soft tissue. Estimated femur blood flow rates among the extinct Macropus, Protemnodon and Sthenurinae (Sthenurus, Simosthenurus and Procoptodon) are not significantly different from one another but are significantly greater than in living hopping macropods after accounting for the effect of body mass, consistent with their purportedly different locomotor style. The giant sthenurines have more robust femora than extrapolated from data of living hopping macropods, possibly due to the larger sthenurines requiring relatively stronger leg bones to support their heavier body weights, especially if loaded onto a single limb during bipedal striding.Open Access funding enabled and organized by CAUL and its Member Institutions This study was supported by Australian Research Council.https://link.springer.com/journal/10914hj2024Anatomy and PhysiologyCentre for Wildlife ManagementNon

Scaling of the ankle extensor muscle-tendon units and the biomechanical implications for bipedal hopping locomotion in the post-pouch kangaroo Macropus fuliginosus

Bipedal hopping is used by macropods, including rat-kangaroos, wallabies and kangaroos (superfamily Macropodoidea). Interspecific scaling of the ankle extensor muscle-tendon units in the lower hindlimbs of these hopping bipeds shows that peak tendon stress increases disproportionately with body size. Consequently, large kangaroos store and recover more strain energy in their tendons, making hopping more efficient, but their tendons are at greater risk of rupture. This is the first intraspecific scaling analysis on the functional morphology of the ankle extensor muscle-tendon units (gastrocnemius, plantaris and flexor digitorum longus) in one of the largest extant species of hopping mammal, the western grey kangaroo Macropus fuliginosus (5.8–70.5 kg post-pouch body mass). The effective mechanical advantage of the ankle extensors does not vary with post-pouch body mass, scaling with an exponent not significantly different from 0.0. Therefore, larger kangaroos balance rotational moments around the ankle by generating muscle forces proportional to weight-related gravitational forces. Maximum force is dependent upon the physiological cross-sectional area of the muscle, which we found scales geometrically with a mean exponent of only 0.67, rather than 1.0. Therefore, larger kangaroos are limited in their capacity to oppose large external forces around the ankle, potentially compromising fast or accelerative hopping. The strain energy return capacity of the ankle extensor tendons increases with a mean exponent of ~1.0, which is much shallower than the exponent derived from interspecific analyses of hopping mammals (~1.4–1.9). Tendon safety factor (ratio of rupture stress to estimated peak hopping stress) is lowest in the gastrocnemius (< 2), and it decreases with body mass with an exponent of −0.15, extrapolating to a predicted rupture at 160 kg. Extinct giant kangaroos weighing 250 kg could therefore not have engaged in fast hopping using ‘scaled-up’ lower hindlimb morphology of extant western grey kangaroos.Organismic and Evolutionary Biolog

Blood flow rate and wall shear stress in seven major cephalic arteries of humans

Please read abstract in the article.Additional Supporting Information: Fig. S1. (A) Blood flow rate (Q_ , cm3 s-1) and (B) calculated wall shear stress (s, dyne cm-2) in seven major cephalic arteries in relation to lumen radius (ri, cm) in humans. The arteries are the common carotid (CCA), internal carotid (ICA), vertebral (VA), basilar (BA), anterior cerebral (ACA), middle cerebral (MCA) and posterior cerebral (PCA). Table S1. Data for cephalic artery size, blood flow rate and wall shear stress taken from 19 published studies of adult humans. Table S2. Mean 95% CI arterial lumen radii, blood flow rates, and calculated wall shear stress (WSS) of single arteries of the human cephalic circulation based on data from 10 exclusively PC-MRI studies.The Australian Research Council Discovery Project Grant DP170104952 to R.S.S.). Q.H. holds an Australian Postgraduate Award.https://onlinelibrary.wiley.com/journal/146975802021-03-01hj2020Anatomy and Physiolog

Frequency of TLR 2, 4, and 9 Gene Polymorphisms in Chinese Population and Their Susceptibility to Type 2 Diabetes and Coronary Artery Disease

Toll-like receptors (TLRs) are pivotal components of the innate immune response. Activation of the innate immune system and subsequent chronic low-grade inflammation are thought to be involved in the pathogenesis of atherosclerosis and type 2 diabetes. In the study, we genotyped TLRs gene polymorphisms, including TLR2 Arg677Trp and Arg753Gln, TLR4 Asp299Gly and Thr399Ile, TLR9-1486T/C and -1237T/C. The frequencies of TT, TC and CC genotype of TLR9-1486T/C mutation were 39.6%, 45.8% and 14.6%, respectively; the frequencies of T allele and C allele were 62.5% and 37.5%. However, neither of these parameters was statistically significant among study groups. In addition, we were surprised to find that the commonly reported TLR SNPs in the Western countries, like TLR2 Arg677Trp or Arg753Gln, TLR4 Asp299Gly or Thr399Ile and TLR9-1237T/C, were not polymorphic at all in all study subjects. In conclusion, our data suggests that TLR2 Arg677Trp or Arg753Gln, TLR4 Asp299Gly or Thr399Ile and TLR9-1237T/C polymorphisms have low frequency and TLR9-1486T/C polymorphism may not be a suitable marker in predicting the susceptibility to type 2 diabetes or coronary artery disease in the Chinese Han population

C/S and B/S mixed structure-based students ideological and political work management system construction

Nowadays, both single C/S, B/S cannot meet each department demands, for students ideological and political work management construction, it needs C/S, B/S mixed structure to jointly complete, the paper carries out advantages and disadvantages analysis and judgment on C/S, B/S single structure, on this basis, utilizes AHP model to analyze C/S, B/S mixed structure in ideological and political work management system, and gets that C/S, B/S mixed structure obtained recognition degree in students’ ideological and political work management is the highest, and analyzes from the ideological and political teachers’ operation ability, the students ability to use, ideological and political management system maintenance, and the degree of system coverage four aspects, and gets students ideological and political work management system’s system construction strength in C/S, B/S mixed structure

Physiological and Psychological Effects of Nature Experiences in Different Forests on Young People

Many studies have proved that having nature experiences in forests is conducive to human physiological and psychological health. However, currently there is little research focusing on the effects of forest characteristics and the experiential characteristics of nature experiences on changes in health. In the study, three types of forest (mixed forest; deciduous forest; coniferous forest) and an urban site were used to measure the effects of these environments on participants’ physiological and psychological restoration after nature experience activities (sitting and walking activities). The study participants were 30 young adult students from Beijing Forestry University. Restorative effects were measured by physiological indicators (blood pressure and heart rate) and four psychological questionnaires (Profile of Mood States (POMS); Restorative Outcome Scale (ROS); Subjective Vitality Scale (SVS); Warwick-Edinburgh Mental Well-being Scale (WEMWBS)). Results demonstrated that all types of forest were beneficial to lower blood pressure and heart rate as well as to reduce negative feelings while boosting positive emotions. The mixed forest was more effective in lowering blood pressure and heart rate as well as increasing vitality. The levels of restoration and positive mental health increased significantly, while all subscales of the POMS (with the exception of vigor) decreased greatly in the coniferous forest. Relative to the sitting activity, obvious decreases in blood pressure and negative emotions were observed, while significant increases in restoration, vitality and positive mental health were observed after the walking activity. In conclusion, the impact on subjects’ health restoration varied with different forest characteristics, and the experiential characteristics of exposure may be helpful for creating supportive interventions and lifting the benefits of forest therapy as people interact with the forest

Structural Characterization and Functional Analysis of Mevalonate Kinase from <i>Tribolium castaneum</i> (Red Flour Beetle)

Mevalonate kinase (MevK) is an important enzyme in the mevalonate pathway that catalyzes the phosphorylation of mevalonate into phosphomevalonate and is involved in juvenile hormone biosynthesis. Herein, we present a structure model of MevK from the red flour beetle Tribolium castaneum (TcMevK), which adopts a compact α/β conformation that can be divided into two parts: an N-terminal domain and a C-terminal domain. A narrow, deep cavity accommodating the substrate and cofactor was observed at the junction between the two domains of TcMevK. Computational simulation combined with site-directed mutagenesis and biochemical analyses allowed us to define the binding mode of TcMevK to cofactors and substrates. Moreover, TcMevK showed optimal enzyme activity at pH 8.0 and an optimal temperature of 40 °C for mevalonate as the substrate. The expression profiles and RNA interference of TcMevK indicated its critical role in controlling juvenile hormone biosynthesis, as well as its participation in the production of other terpenoids in T. castaneum. These findings improve our understanding of the structural and biochemical features of insect Mevk and provide a structural basis for the design of MevK inhibitors

The hierarchical model of la-la-la role in campus culture construction

La-la-la operating in the construction of colleges and universities has a great value, can promote the students’ physical and mental health, colleagues to promote the construction of campus culture, different ways of la-la-la operating organization implement and carry out on all aspects of the role is not the same. Solutions are mainly in the colleges and universities to build operation association, organization propaganda, carry out la-la-la operating activities to promote and enhance the campus spiritual civilization construction and strengthen students’ self-confidence and moral quality. Based on the AHP method to study la-la-la hold different organization form for the role of the campus culture construction, and to quantify value, said the results. The school should take the classroom education is complementary, held mainly operating activities stimulate la-la-la fuck role in campus culture construction