Predictors of Concussion Symptom-Reporting Intention Among Collegiate Athletes.

Context: Underreporting of concussion symptoms in college athletics presents a challenge for sports medicine clinicians in evaluating and diagnosing such injuries. Some athletes do not report concussion symptoms because they do not recognize that they have a brain injury; however, many athletes intentionally withhold symptoms to avoid removal from sport participation.

Objective: To examine individual factors that influence college athletes' intentions to report concussion symptoms.

Megalithic tombs in western and northern Neolithic Europe were linked to a kindred society.

Paleogenomic and archaeological studies show that Neolithic lifeways spread from the Fertile Crescent into Europe around 9000 BCE, reaching northwestern Europe by 4000 BCE. Starting around 4500 BCE, a new phenomenon of constructing megalithic monuments, particularly for funerary practices, emerged along the Atlantic façade. While it has been suggested that the emergence of megaliths was associated with the territories of farming communities, the origin and social structure of the groups that erected them has remained largely unknown.

Masticatory biomechanics in the rabbit: a multi-body dynamics analysis.

Multi-body dynamics is a powerful engineering tool which is becoming increasingly popular for the simulation and analysis of skull biomechanics. This paper presents the first application of multi-body dynamics to analyse the biomechanics of the rabbit skull. A model has been constructed through the combination of manual dissection and three-dimensional imaging techniques (magnetic resonance imaging and micro-computed tomography).

Development and three-dimensional morphology of the zygomaticotemporal suture in primate skulls.

Cranial sutures are an essential part of the growing skull, allowing bones to increase in size during growth, with their morphology widely believed to be dictated by the forces and displacements that they experience. The zygomaticotemporal suture in primates is located in the relatively weak zygomatic arch, and externally it appears a very simple connection. However, large forces are almost certainly transmitted across this suture, suggesting that it requires some level of stability while also allowing controlled movements under high loading.

Perceived levels of frustration during clinical situations in athletic training students.

Context: Athletic training students (ATSs) are involved in various situations during the clinical experience that may cause them to express levels of frustration. Understanding levels of frustration in ATSs is important because frustration can affect student learning, and the clinical experience is critical to their development as professionals.

Objective: To explore perceived levels of frustration in ATSs during clinical situations and to determine if those perceptions differ based on sex.

Cranial sutures work collectively to distribute strain throughout the reptile skull.

The skull is composed of many bones that come together at sutures. These sutures are important sites of growth, and as growth ceases some become fused while others remain patent. Their mechanical behaviour and how they interact with changing form and loadings to ensure balanced craniofacial development is still poorly understood.

The importance of accurate muscle modelling for biomechanical analyses: a case study with a lizard skull.

Computer-based simulation techniques such as multi-body dynamics analysis are becoming increasingly popular in the field of skull mechanics. Multi-body models can be used for studying the relationships between skull architecture, muscle morphology and feeding performance. However, to be confident in the modelling results, models need to be validated against experimental data, and the effects of uncertainties or inaccuracies in the chosen model attributes need to be assessed with sensitivity analyses.

The head and neck anatomy of sea turtles (Cryptodira: Chelonioidea) and skull shape in Testudines.

Background: Sea turtles (Chelonoidea) are a charismatic group of marine reptiles that occupy a range of important ecological roles. However, the diversity and evolution of their feeding anatomy remain incompletely known.

Methodology/principal Findings: Using computed tomography and classical comparative anatomy we describe the cranial anatomy in two sea turtles, the loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii), for a better understanding of sea turtle functional anatomy and morphological variation.

Developing a musculoskeletal model of the primate skull: predicting muscle activations, bite force, and joint reaction forces using multibody dynamics analysis and advanced optimisation methods.

An accurate, dynamic, functional model of the skull that can be used to predict muscle forces, bite forces, and joint reaction forces would have many uses across a broad range of disciplines. One major issue however with musculoskeletal analyses is that of muscle activation pattern indeterminacy. A very large number of possible muscle force combinations will satisfy a particular functional task.

Shearing mechanics and the influence of a flexible symphysis during oral food processing in Sphenodon (Lepidosauria: Rhynchocephalia).

The New Zealand tuatara, Sphenodon, has a specialized feeding system in which the teeth of the lower jaw close between two upper tooth rows before sliding forward to slice food apart like a draw cut saw. This shearing action is unique amongst living amniotes but has been compared with the chewing power stroke of mammals. We investigated details of the jaw movement using multibody dynamics analysis of an anatomically accurate three-dimensional computer model constructed from computed tomography scans.

Functional relationship between skull form and feeding mechanics in Sphenodon, and implications for diapsid skull development.

The vertebrate skull evolved to protect the brain and sense organs, but with the appearance of jaws and associated forces there was a remarkable structural diversification. This suggests that the evolution of skull form may be linked to these forces, but an important area of debate is whether bone in the skull is minimised with respect to these forces, or whether skulls are mechanically "over-designed" and constrained by phylogeny and development. Mechanical analysis of diapsid reptile skulls could shed light on this longstanding debate.

Discovery of GSK143, a highly potent, selective and orally efficacious spleen tyrosine kinase inhibitor.

The lead optimisation of the diaminopyrimidine carboxamide series of spleen tyrosine kinase inhibitors is described. The medicinal chemistry strategy was focused on optimising the human whole blood activity whilst achieving a sufficient margin over liability kinases and hERG activity. GSK143 is a potent and highly selective SYK inhibitor showing good efficacy in the rat Arthus model.

The mechanical significance of the temporal fasciae in Macaca fascicularis: an investigation using finite element analysis.

Computational finite element analyses (FEAs) of the skull predict structural deformations under user specified loads and constraints, with results normally presented as stress and strain distributions over the skull's surface. The applied loads are generally a representation of the major adductor musculature, with the skull constrained at bite positions and at the articulating joints. However, virtually all analyses ignore potentially important anatomical structures, such as the fasciae that cover the temporalis muscle and attach onto the zygomatic arch.

Craniofacial biomechanics: an overview of recent multibody modelling studies.

Multibody modelling is underutilised in craniofacial analyses, particularly when compared to other computational methods such as finite element analysis. However, there are many potential applications within this area, where bony movements, muscle forces, joint kinematics and bite forces can all be studied. This paper provides an overview of recent, three-dimensional, multibody modelling studies related to the analysis of skulls.

Predicting muscle activation patterns from motion and anatomy: modelling the skull of Sphenodon (Diapsida: Rhynchocephalia).

The relationship between skull shape and the forces generated during feeding is currently under widespread scrutiny and increasingly involves the use of computer simulations such as finite element analysis. The computer models used to represent skulls are often based on computed tomography data and thus are structurally accurate; however, correctly representing muscular loading during food reduction remains a major problem. Here, we present a novel approach for predicting the forces and activation patterns of muscles and muscle groups based on their known anatomical orientation (line of action).

Biomechanical assessment of evolutionary changes in the lepidosaurian skull.

The lepidosaurian skull has long been of interest to functional morphologists and evolutionary biologists. Patterns of bone loss and gain, particularly in relation to bars and fenestrae, have led to a variety of hypotheses concerning skull use and kinesis. Of these, one of the most enduring relates to the absence of the lower temporal bar in squamates and the acquisition of streptostyly.

Gamma-secretase-dependent cleavage of amyloid precursor protein regulates osteoblast behavior.

gamma-Secretase cleaves amyloid precursor protein (APP) to generate amyloid-beta (Abeta) peptides, which aggregate in the brain in Alzheimer's disease (AD). gamma-Secretase also cleaves molecules that regulate osteoblast activity, such as Notch and ephrinB2. However, the role of APP in bone is unknown.

Assessment of the role of sutures in a lizard skull: a computer modelling study.

Sutures form an integral part of the functioning skull, but their role has long been debated among vertebrate morphologists and palaeontologists. Furthermore, the relationship between typical skull sutures, and those involved in cranial kinesis, is poorly understood. In a series of computational modelling studies, complex loading conditions obtained through multibody dynamics analysis were imposed on a finite element model of the skull of Uromastyx hardwickii, an akinetic herbivorous lizard.

A new approach to amino acid racemization in enamel: testing of a less destructive sampling methodology.

Aspartic acid racemization has been found to be an accurate measure of age at death for recent forensic material. This paper examines the practicality of using acid etching of the tooth surface to extract amino acids from the enamel for racemization analysis. By serial etching of the tooth and contamination of the teeth with bovine serum albumin prior to etching, the ability of etching to remove contamination was assessed.

Predicting skull loading: applying multibody dynamics analysis to a macaque skull.

Evaluating stress and strain fields in anatomical structures is a way to test hypotheses that relate specific features of facial and skeletal morphology to mechanical loading. Engineering techniques such as finite element analysis are now commonly used to calculate stress and strain fields, but if we are to fully accept these methods we must be confident that the applied loading regimens are reasonable. Multibody dynamics analysis (MDA) is a relatively new three dimensional computer modeling technique that can be used to apply varying muscle forces to predict joint and bite forces during static and dynamic motions.

Synthesis of (+)-obtusenyne.

An enantioselective synthesis of the halogenated medium-ring ether natural product (+)-obtusenyne is reported which uses the ring expansion of a seven-membered ketene acetal by means of a Claisen rearrangement to construct the core nine-membered oxygen heterocycle. The trans substituents across the ether linkage were established by using a transition-metal-catalyzed intramolecular hydrosilation reaction of an exo-cyclic enol ether. In addition, a formal synthesis of ent-obtusenyne from 2-deoxy-D-ribose is reported.

A cobalt(III) compound of a 13-membered cyclic tetraamine: trans-(12,12-dimethyl-1,4,7,10-tetraazacyclotetradecane)diisothiocyanatocobalt(III) tetraisothiocyanatozinc(II) ethanol solvate.

The title compound, [Co(NCS)2(C11H26N4)]2[Zn(NCS)4].C2H5OH, has two similar cations with the Co(III) atom coordinated in a planar fashion by the 13-membered cyclic tetraamine, in the 1R,4S,7R,10S configuration, and with trans isothiocyanate ligands. The six-membered chelate ring is in a chair conformation, with one axially and one equatorially oriented methyl substituent [mean Co-N = 1.

(4,4,12,12-Tetramethyl-5,8,11-triazapenta-2,14-dione 2-oxime 14-oximato-kappa(5)N)copper(II) perchlorate: a copper(II) compound with a pentadentate triamine-oxime-oximate ligand.

The title compound, [Cu(C(16)H(34)N(5)O(2))]ClO(4), has discrete square-pyramidal (triamine-oxime-oximato)copper(II) cations and perchlorate anions. The cations have very approximate mirror symmetry, with the oxime [Cu-N = 2.066 (2) A], oximate [Cu-N = 2.