The thickness of the calcified layer of articular cartilage

The thickness of both the articular cartilage and its calcified zone were measured at 25 carefully selected points in 8 human femoral heads, and the ratio of one to the other was found to be remarkably constant for each bone. The thickness of the calcified zone therefore shows the same distribution pattern as that of the total cartilage and, since the latter is dependent upon the distribution of the load, the thickness of the calcified region also appears to be related to mechanical stress. The volume of the calcified zone, however, expressed as a percentage of the total cartilage, varied considerably from one bone to another within the range from 3.23 to 8.8%. Too few specimens were examined to allow correlation with age or sex to be either refuted or confirmed

The thickness of the calcified layer in different joints of a single individual

The thickness of the articular cartilage and its calcified zone were both measured at specially chosen places in several limb joints from five subjects. The volume of the calcified zone expressed as a percentage of the total cartilage was not only constant for one joint, but also in all the joints of a single individual. Nevertheless, the variation between subjects ranges from 6.9 to 8.6%. In two cases both sides of the body were investigated. As was the case in an earlier investigation on the femoral head, the bilateral distribution of the thickness was the same. Since the thickness of the total cartilage varies with the local distribution of loading in the joint, it follows that the thickness of the calcified layer also depends upon mechanical factors. Five subjects is too few to allow correlation with age or sex to be either refuted or confirmed. There is some evidence in the existing literature that the thickness of the calcified zone may be altered by diseas

Characterisation of Leishmania amino acid permease 3 (AAP3) coding sequences and flanking regions as a target of detection and diagnosis of the leishmaniases

Postponed access: the file will be accessible after 2020-11-29The protozoan parasites of Leishmania genus are the etiological agents of the leishmaniases, diseases whose clinical manifestations range from being asymptomatic, self-healing cutaneous lesions, via mutilating muco-cutaneous lesions, to a potentially lethal visceral form. The World Health Organization defines the leishmaniases as neglected tropical diseases (NTDs). The aim of this thesis was to explore a new potential target, the amino acid permease 3 (aap3) coding regions and flanking nucleotide sequences for parasite detection and species identification. In four papers, the findings from research on the general and specific aims are presented. In paper I, theaap3 coding sequence was investigated for its potential as a target for parasite detection. Using real-time polymerase chain reaction (real-time PCR) the developed assay was useful for qualitative purposes, and when run in duplex with a host specific gene-assay, it was also able to quantify parasites in the mammal host. In paper II, the aap3coding sequence was investigated for its potential as a target for species discrimination. Using high resolution melting (HRM) analysis, aap3was found to be a specific and sensitive target for Leishmania species-identification. The method was validated on samples from humans, from experimentally infected mice, as well as from naturally infected sand flies. In paper III, a multi-centre prospective clinical study on the occurrence, diagnosis, treatment of the leishmaniases in Norway was performed. Biopsy material was collected to validate aap3as a target in clinical samples. In this material, the small subunit ribosomal RNA coding sequence (SSU rDNA), a molecular target routinely used in Leishmaniadetection tests, was found to be more sensitive in conventional PCR assays. Skin biopsy was the most appropriate material for diagnosis in cutaneous leishmaniasis. In paper IV,the aap3gene region from several Leishmaniaspecies was sequenced using single molecule real-time (SMRT) sequencing. In all species analysed, two copies of the encoding gene sequences organized in tandemwere found. These sequences are conserved within the species and between species of the same subgenera. In conclusion, this thesis shows that aap3with appropriate technology can be a sensitive and specific target for both genus detection and species discrimination. Furthermore, precise sequencing of aap3, as described here, can be a very useful tool in subsequent gene editing studies for a better understanding of the physiology and genetics of these parasites

On the Calculation of Solid-Fluid Contact Angles from Molecular Dynamics

A methodology for the determination of the solid-fluid contact angle, to be employed within molecular dynamics (MD) simulations, is developed and systematically applied. The calculation of the contact angle of a fluid drop on a given surface, averaged over an equilibrated MD trajectory, is divided in three main steps: (i) the determination of the fluid molecules that constitute the interface, (ii) the treatment of the interfacial molecules as a point cloud data set to define a geometric surface, using surface meshing techniques to compute the surface normals from the mesh, (iii) the collection and averaging of the interface normals collected from the post-processing of the MD trajectory. The average vector thus found is used to calculate the Cassie contact angle (i.e., the arccosine of the averaged normal z-component). As an example we explore the effect of the size of a drop of water on the observed solid-fluid contact angle. A single coarse-grained bead representing two water molecules and parameterized using the SAFT-γ Mie equation of state (EoS) is employed, meanwhile the solid surfaces are mimicked using integrated potentials. The contact angle is seen to be a strong function of the system size for small nano-droplets. The thermodynamic limit, corresponding to the infinite size (macroscopic) drop is only truly recovered when using an excess of half a million water coarse-grained beads and/or a drop radius of over 26 nm

Computed tomography-osteoaboorptiometry

A method of making a visual display of subchondral mineralization in the major synovial joints is described. Unlike existing procedures, it can be used on the living subject. A modified application of computed tomography-densitometry, computed tomography-osteoabsorptiometry makes it possible to explore the mechanical adaptability to the prevailing mechanical force. This claim is based upon the comparison of information obtained from 20 anatomical specimens with CT-osteoabsorptiometry and x-ray densitometry of sections; both methods yielding virtually identical results. The distribution of the subchondral density was then expressed as a map of the articular surface with the aid of an image analyser. This method can make a useful contribution to basic clinical research, as well as providing a diagnostic technique which can also be used for observing progress after a corrective osteotomy or any other procedure causing a change in mechanical function. Examples of its use on living patients are given

Two-Sample Testing for Event Impacts in Time Series

In many application domains, time series are monitored to detect extreme events like technical faults, natural disasters, or disease outbreaks. Unfortunately, it is often non-trivial to select both a time series that is informative about events and a powerful detection algorithm: detection may fail because the detection algorithm is not suitable, or because there is no shared information between the time series and the events of interest. In this work, we thus propose a non-parametric statistical test for shared information between a time series and a series of observed events. Our test allows identifying time series that carry information on event occurrences without committing to a specific event detection methodology. In a nutshell, we test for divergences of the value distributions of the time series at increasing lags after event occurrences with a multiple two-sample testing approach. In contrast to related tests, our approach is applicable for time series over arbitrary domains, including multivariate numeric, strings or graphs. We perform a large-scale simulation study to show that it outperforms or is on par with related tests on our task for univariate time series. We also demonstrate the real-world applicability of our approach on datasets from social media and smart home environments.Comment: SIAM International Conference on Data Mining (SDM 2020) preprint, source code and supplementary material is available at https://github.com/diozaka/eites

Physiological incongruity of the humero-ulnar joint

Investigations into the distribution of subchondral bone density in the human elbow have suggested that the geometry of the trochlear notch deviates from a perfect fit with the trochlea, and that the load is transmitted ventrally and dorsally rather than through the centre of the humero-ulnar joint. We therefore decided to make a quantitative assessment of the degree of incongruity between the two components in 15 human specimens (age distribution 60 to 93 years) with different types of joint surface. Polyether casts of the joint cavity were prepared under loads of 10,40,160 and 640 N. The thickness of the casts was then measured at 50 predetermined points, and an area distribution of the width of the joint space represented in a two-dimensional template of the trochlear notch. The reproducibility of this procedure was tested by image analysis. At a load of 10 N, only a narrow space was present ventrally and dorsally in the joint, but in the depths of the trochlear notch a width of 0.5 to 1 mm was recorded in the centre, and up to 3 mm at its medial and lateral edges. Specimens with continuous articular cartilage showed a lower degree of incongruity than those with a divided articular surface. As the load was increased to 640 N, however, the original incongruity between the articular surfaces disappeared almost completely. The joint surfaces became more congruous, probably because of the viscoelastic properties of the articular cartilage and the subchondral bone, and the contact areas merged in the centre of the joint. It is suggested that this physiological incongruity brings about an optimal distribution of stress over the articular surface during the transmission of the load, and it may lead to better nourishment of the articular cartilage by providing intermittent mechanical stimulation and circulation of the synovial fluid