Leaping and Accelerometry: A Theoretical Approach

Accelerometry has always been a popular method of monitoring locomotor activity but its use is becoming more widespread due to the easy availability of low cost, low power sensors. However one of the major problems with interpreting accelerometer data is that rotation of the sensor alters the output and obtaining independent orientation information is currently difficult. For the specific case of leaping locomotion full orientation information is unecessary as long as an independent measure of height change is available such as can be obtained from a sensitive pressure sensor. Therefore a 4 channel logging system recording 3 accelerometry axes combined with a channel measuring pressure could be used to accurately assess leaping locomotion. This approach should also work for any locomotion where acceleration is limited to the vertical plane but in practice it may be restricted by the sensitivity and acquisition characteristics of the pressure measurement system. Ultimately it should be a useful addition to the range of measurements available for remote locomotor monitoring particularly for leaping species such as lemurs and other non-human primates

Analyzing Images, Editing Texts: The Manchester Project

This article discusses the methodologies and tools employed in the study of the Syriac Galen Palimpsest. While it focusses on the efforts of the ongoing Manchester Project, attention is also paid to earlier and contemporary work, particularly the most recent phase of research (which can be said to have started in 2009). In this way, the Manchester Project is properly contextualised. We describe the image analysis techniques employed by the Manchester team. The challenge is to reduce the information contained in the set of multi-spectral images and enhance it where it can usefully distinguish between undertext and overtext. One can either use unsupervised or supervised dimensional reduction techniques. An unsupervised method such as principle component analysis (PCA) provides an automatic result, whereas a supervised method such as Canonical Variates Analysis (CVA) requires one to teach the system by identifying blank areas, areas with only overtext, areas with only undertext, and areas with both. Using the resulting improvements to the visibility of the undertext, the Manchester team has been able to make significant advances in identifying where its folios fit into Galen’s Book of Simple Drugs. The use of a program called SketchEngine is outlined, which permits an engagement with parallel Greek and Syriac texts and powerful searches - this is particularly useful for those folios that come from Books 6–8, for which a parallel Syriac manuscript exists. Having completed this initial stage, it became clear that around 100 folios that did not come from Books 6-8 remained to be identified. SketchEngine again has proved to be very useful in facilitating identifications of these folios. To illustrate the different challenges posed by these two distinct scenarios, examples are provided from Books 5 and 8

The Syriac Galen Palimpsest: A Tale of Two Texts

This article presents the Syriac Galen Palimpsest’s double history, of both the original manuscript and its subsequent reuse. The original medical manuscript contained Galen’s Book of Simple Drugs in Syriac translation, was probably produced in northern Mesopotamia or western Syria, and dates to the first half of the ninth century. After only two centuries, it was erased and reused to produce a liturgical text called Octṓēchos, probably at the monastery of Saint Elias on the Black Mountain. This palimpsest was later transferred to Saint Catherine’s monastery in the Sinai, where it remained for several centuries before being offered for sale in Leipzig in 1922 (perhaps due to the activities of Friedrich Grote). We pay close attention to the context, contents, codicology and palaeography of both the original manuscript and the palimpsest. We also contextualise both texts within the wider story of their transmission. Through the skeleton table we present the latest results of our almost complete identification of the undertext. We reconstruct the structure of the original codex through a collation diagram. We draw palaeographical parallels with a dated colophon of the well-known Sahdona-manuscript. This permits us to narrow done the time and place of production of the original manuscript

Convex hull estimation of mammalian body segment parameters

From The Royal Society via Jisc Publications RouterHistory: received 2021-05-18, collection 2021-06, accepted 2021-06-14, pub-electronic 2021-06-30Article version: VoRPublication status: PublishedFunder: Manchester Environmental Research InstituteFunder: Natural Environment Research Council; Id: http://dx.doi.org/10.13039/501100000270; Grant(s): NE/R011168/1Obtaining accurate values for body segment parameters (BSPs) is fundamental in many biomechanical studies, particularly for gait analysis. Convex hulling, where the smallest-possible convex object that surrounds a set of points is calculated, has been suggested as an effective and time-efficient method to estimate these parameters in extinct animals, where soft tissues are rarely preserved. We investigated the effectiveness of convex hull BSP estimation in a range of extant mammals, to inform the potential future usage of this technique with extinct taxa. Computed tomography scans of both the skeleton and skin of every species investigated were virtually segmented. BSPs (the mass, position of the centre of mass and inertial tensors of each segment) were calculated from the resultant soft tissue segments, while the bone segments were used as the basis for convex hull reconstructions. We performed phylogenetic generalized least squares and ordinary least squares regressions to compare the BSPs calculated from soft tissue segments with those estimated using convex hulls, finding consistent predictive relationships for each body segment. The resultant regression equations can, therefore, be used with confidence in future volumetric reconstruction and biomechanical analyses of mammals, in both extinct and extant species where such data may not be available

High tumor incidence and activation of the PI3K/AKT pathway in transgenic mice define AIB1 as an oncogene

AbstractThe gene encoding AIB1, an estrogen receptor coactivator, is amplified in a subset of human breast cancers. Here we show that overexpression of AIB1 in transgenic mice (AIB1-tg) leads to mammary hypertrophy, hyperplasia, abnormal postweaning involution, and the development of malignant mammary tumors. Tumors are also increased in other organs, including the pituitary and uterus. AIB1 overexpression increases mammary IGF-I mRNA and serum IGF-I protein levels. In addition, IGF-I receptor and downstream signaling molecules are activated in primary mammary epithelial cells and mammary tumor cells derived from AIB1-tg mice. Knockdown of AIB1 expression in cultured AIB1-tg mammary tumor cells leads to reduced IGF-I mRNA levels and increased apoptosis, suggesting that an autocrine IGF-I loop underlies the mechanism of AIB1-induced oncogenesis

Continuing research on the Syriac Galen Palimpsest:Collaborative Implementation within the Framework of Two European Projects

International audienc

Turning turtle: scaling relationships and self-righting ability in Chelydra serpentina

From The Royal Society via Jisc Publications RouterHistory: received 2021-01-26, accepted 2021-01-28, pub-electronic 2021-03-03, pub-print 2021-03-10Article version: VoRPublication status: PublishedFunder: Leverhulme Trust; Id: http://dx.doi.org/10.13039/501100000275; Grant(s): RPG-2019-104Testudines are susceptible to inversion and self-righting using their necks, limbs or both, to generate enough mechanical force to flip over. We investigated how shell morphology, neck length and self-righting biomechanics scale with body mass during ontogeny in Chelydra serpentina, which uses neck-powered self-righting. We found that younger turtles flipped over twice as fast as older individuals. A simple geometric model predicted the relationships of shell shape and self-righting time with body mass. Conversely, neck force, power output and kinetic energy increase with body mass at rates greater than predicted. These findings were correlated with relatively longer necks in younger turtles than would be predicted by geometric similarity. Therefore, younger turtles self-right with lower biomechanical costs than predicted by simple scaling theory. Considering younger turtles are more prone to inverting and their shells offer less protection, faster and less costly self-righting would be advantageous in overcoming the detriments of inversion

Inferring cost of transport from whole-body kinematics in three sympatric turtle species with different locomotor habits

Chelonians are mechanically unusual vertebrates as an exoskeleton limits their body wall mobility. They generallymove slowly on land and have aquatic or semi-aquatic lifestyles. Somewhat surprisingly, the limitedexperimental work that has been done suggests that their energetic cost of transport (CoT) are relatively low.This study examines the mechanical evidence for CoT in three turtle species that have differing degrees ofterrestrial activity. Our results show that Apolone travels faster than the other two species, and that Chelydra hashigher levels of yaw. All the species show poor mean levels of energy recovery, and, whilst there is considerablevariation, never show the high levels of energy recovery seen in cursorial quadrupeds. The mean mechanical CoTis 2 to 4 times higher than is generally seen in terrestrial animals. We therefore find no mechanical support for alow CoT in these species. This study illustrates the need for research on a wider range of chelonians to discoverwhether there are indeed general trends in mechanical and metabolic energy costs

Scaling of axial muscle architecture in juvenile Alligator mississippiensis reveals an enhanced performance capacity of accessory breathing mechanisms

From Wiley via Jisc Publications RouterHistory: received 2020-11-16, rev-recd 2021-07-08, accepted 2021-07-12, pub-electronic 2021-07-23Article version: VoRPublication status: PublishedFunder: Biotechnology and Biological Sciences Research Council; Id: http://dx.doi.org/10.13039/501100000268; Grant(s): BB/I021116/1Funder: National Science Foundation; Id: http://dx.doi.org/10.13039/100000001; Grant(s): 17565187Abstract: Quantitative functional anatomy of amniote thoracic and abdominal regions is crucial to understanding constraints on and adaptations for facilitating simultaneous breathing and locomotion. Crocodilians have diverse locomotor modes and variable breathing mechanics facilitated by basal and derived (accessory) muscles. However, the inherent flexibility of these systems is not well studied, and the functional specialisation of the crocodilian trunk is yet to be investigated. Increases in body size and trunk stiffness would be expected to cause a disproportionate increase in muscle force demands and therefore constrain the basal costal aspiration mechanism, necessitating changes in respiratory mechanics. Here, we describe the anatomy of the trunk muscles, their properties that determine muscle performance (mass, length and physiological cross‐sectional area [PCSA]) and investigate their scaling in juvenile Alligator mississippiensis spanning an order of magnitude in body mass (359 g–5.5 kg). Comparatively, the expiratory muscles (transversus abdominis, rectus abdominis, iliocostalis), which compress the trunk, have greater relative PCSA being specialised for greater force‐generating capacity, while the inspiratory muscles (diaphragmaticus, truncocaudalis ischiotruncus, ischiopubis), which create negative internal pressure, have greater relative fascicle lengths, being adapted for greater working range and contraction velocity. Fascicle lengths of the accessory diaphragmaticus scaled with positive allometry in the alligators examined, enhancing contractile capacity, in line with this muscle's ability to modulate both tidal volume and breathing frequency in response to energetic demand during terrestrial locomotion. The iliocostalis, an accessory expiratory muscle, also demonstrated positive allometry in fascicle lengths and mass. All accessory muscles of the infrapubic abdominal wall demonstrated positive allometry in PCSA, which would enhance their force‐generating capacity. Conversely, the basal tetrapod expiratory pump (transversus abdominis) scaled isometrically, which may indicate a decreased reliance on this muscle with ontogeny. Collectively, these findings would support existing anecdotal evidence that crocodilians shift their breathing mechanics as they increase in size. Furthermore, the functional specialisation of the diaphragmaticus and compliance of the body wall in the lumbar region against which it works may contribute to low‐cost breathing in crocodilians

Evidence for a Mass Dependent Step-Change in the Scaling of Efficiency in Terrestrial Locomotion

A reanalysis of existing data suggests that the established tenet of increasing efficiency of transport with body size in terrestrial locomotion requires re-evaluation. Here, the statistical model that described the data best indicated a dichotomy between the data for small (<1 kg) and large animals (>1 kg). Within and between these two size groups there was no detectable difference in the scaling exponents (slopes) relating metabolic (Emet) and mechanical costs (Emech, CM) of locomotion to body mass (Mb). Therefore, no scaling of efficiency (Emech, CM/Emet) with Mb was evident within each size group. Small animals, however, appeared to be generally less efficient than larger animals (7% and 26% respectively). Consequently, it is possible that the relationship between efficiency and Mb is not continuous, but, rather, involves a step-change. This step-change in the efficiency of locomotion mirrors previous findings suggesting a postural cause for an apparent size dichotomy in the relationship between Emet and Mb. Currently data for Emech, CM is lacking, but the relationship between efficiency in terrestrial locomotion and Mb is likely to be determined by posture and kinematics rather than body size alone. Hence, scaling of efficiency is likely to be more complex than a simple linear relationship across body sizes. A homogenous study of the mechanical cost of terrestrial locomotion across a broad range of species, body sizes, and importantly locomotor postures is a priority for future research