Storm influences on sand wave dynamics:an idealized modelling approach

We investigate the influence of wind waves and wind-driven flow on sand wave dynamics using a two-model approach. Using a linear stability analysis, we find that waves decrease sand wave growth and wind causes sand wave migration. Combining linear stability analysis with a typical North Sea wave and wind climate explains variability in sand wave migration rates. Using a nonlinear sand wave model we show that waves reduce sand wave height and wind causes sand wave asymmetry as well as migration

Aerial dissemination of Clostridium difficile spores inside and outside a pig farm

In both human and veterinary medicine Clostridium difficile infections are increasingly reported. The observation that aerial dissemination occurs in a hospital environment and can pla a role in the transmission of human C. difficile infection, resulted in the present study to the occurence of airborne C. difficile in, and nearby a pig farm with a high prevalence of C. difficile

A 19-channel d.c. SQUID magnetometer system for brain research

A 19-channel d.c. SQUID magnetometer system for neuromagnetic investigations is under constuction. The first-order gradiometers for sensing the signal are placed in a hexagonal configuration. D.c. SQUIDs based on niobium/aluminium technology have been developed, leading to a field sensitivity of about 5 fT/ Hz. SQUID read-out is realized with a resonant transformer circuit at 100 kHz. The multichannel control and detection electronics are compactly built

Otitis Media Diagnosis for Developing Countries Using Tympanic Membrane Image-Analysis

AbstractBackgroundOtitis media is one of the most common childhood diseases worldwide, but because of lack of doctors and health personnel in developing countries it is often misdiagnosed or not diagnosed at all. This may lead to serious, and life-threatening complications. There is, thus a need for an automated computer based image-analyzing system that could assist in making accurate otitis media diagnoses anywhere.MethodsA method for automated diagnosis of otitis media is proposed. The method uses image-processing techniques to classify otitis media. The system is trained using high quality pre-assessed images of tympanic membranes, captured by digital video-otoscopes, and classifies undiagnosed images into five otitis media categories based on predefined signs. Several verification tests analyzed the classification capability of the method.FindingsAn accuracy of 80.6% was achieved for images taken with commercial video-otoscopes, while an accuracy of 78.7% was achieved for images captured on-site with a low cost custom-made video-otoscope.InterpretationThe high accuracy of the proposed otitis media classification system compares well with the classification accuracy of general practitioners and pediatricians (~64% to 80%) using traditional otoscopes, and therefore holds promise for the future in making automated diagnosis of otitis media in medically underserved populations

Predictive value of fear avoidance in developing chronic neck pain disability: consequences for clinical decision making

Objective\ud To improve clinical decision making in posttraumatic neck pain by investigating the additional value of fear-avoidance variables in predicting chronic neck pain disability.\ud \ud Design\ud An inception cohort with baseline assessment 1 week posttrauma and outcome assessment 24 weeks posttrauma. Predictive factors include pain intensity, Neck Disability Index (NDI), catastrophizing, fear of movement (Tampa Scale for Kinesiophobia [TSK]), and avoidance muscle behavior.\ud \ud Setting\ud Hospital emergency department of a general hospital.\ud \ud Participants\ud A consecutive sample of 90 people reporting of pain in neck or head region after a motor vehicle collision. Eighty-two subjects (91.1%) of the sample provided 24-week follow-up on the outcome.\ud \ud Interventions\ud Not applicable.\ud \ud Main outcome measure\ud The NDI assessing physical disability of subjects with neck pain.\ud \ud Results\ud By using a combination of the baseline NDI and TSK, it appears to be possible to predict chronic disability with a probability of 54.3% (95% confidence interval [CI], 35.2%–72.3%) after entering the NDI (cutoff, 15) as a first test, and with a probability of 83.3% (95% CI, 70.3%–91.3%) after entering the TSK (cutoff, 40) in a second test.\ud \ud Conclusions\ud A simple rating of baseline neck pain disability within a week of the trauma, separately or in combination with a test for fear of movement, can be used to predict future outcome. Patients showing fear of movement can be offered an intervention that focuses on reduction of this fear.\ud \u

Cartilage adhesive and mechanical properties of enzymatically crosslinked polysaccharide tyramine conjugate hydrogels

Using a home-built tensile tester, adhesion and mechanical properties of injectable enzymatically crosslinkable hydrogels were determined by placing the hydrogels in between cartilage surfaces. Dextran–tyramine (Dex-TA) and hyaluronic acid–tyramine (HA-TA) conjugates as well as a 50/50 composite material of these polysaccharide conjugates were tested. To integrate the injectable hydrogels with the cartilage tissue, pretreatment of the tissue with a Dex-TA conjugate solution strongly improved the adhesion. Only failure of the crosslinked hydrogel was observed and not at the hydrogel–tissue interface. Moduli of a Dex-TA hydrogel are higher than those of a HA-TA hydrogel, whereas the ultimate strain of the HA-TA hydrogel was at least three times higher. The Dex-TA/HA-TA hydrogel has similar storage and elastic moduli as the Dex-TA gel and also an ultimate strain of ~30%, similarly as found for the HA-TA gel. The controlled biodegradability and gelation time of the Dex-TA/HA-TA hydrogel, the developed method for strong tissue adhesion of the gel particularly in comparison with fibrin glue, makes this material applicable as an injectable hydrogel for tissue regeneration application

Measurement of physical quantities in upper-limb tele-rehabilitation

A total of 50 patients (affected by traumatic brain injury, stroke or multiple sclerosis) were treated for one month using a rehabilitation protocol. Rehabilitation could be monitored using a Portable Unit (PU) which could be installed in a patient's home allowing the measurement of kinetic and kinematic variables during exercise. In a preliminary analysis, the variables related to four rehabilitation exercises were examined for two patients at baseline and at the end of the one-month treatment. The exercises involved movement of checkers, a pencil, a jar and a key. The results suggest that, even if the overall duration of exercise execution is an important aspect of the rehabilitation process, other variables acquired by the PU might deliver useful information for assessing the patient's status. In order to integrate such variables into the assessment process, further studies are needed to investigate their eventual correlation with traditional rehabilitation scales and variables

Morphological changes associated with Nile crocodile (Crocodylus niloticus) phallic glans inflation

The crocodylian phallic glans is the distal inflatable structure that makes the most direct contact with the female cloacal and associated reproductive tract openings during copulation. Therefore, its form and function directly impact female tissue sensory interactions and insemination mechanics. Compared to mammals, less is known about glans functional anatomy among other amniotes, including crocodylians. Therefore, we paired an ex vivo inflation technique with magnetic resonance imaging 3D-reconstructions and corresponding histological analyses to better characterize the morphological glans restructuring occurring in the Nile crocodile (Crocodylus niloticus) at copulation. The expansion of contiguous inflatable spongiform glans tissues is variably constrained by adjacent regions of dense irregular collagen-rich tissues. Therefore, expansion shows regional differences with greater lateral inflation than dorsal and ventral. Furthermore, this enlargement elaborates the cup-like glans lumen, dorsally reorients the glans ridge, stiffens the blunt and bifid glans tip, and putatively works to seal the ventral sulcus spermaticus semen conduit groove. We suggest how these dynamic male structures may interact with structures of the female cloacal urodeum and how these morphological changes, in concert with the varying material properties of the structural tissue compartments visualized in this study, aid copulatory gamete transfer and resulting fecundity. RESEARCH HIGHLIGHTS : Nile crocodile glans inflation produces a reproductively relevant copulatory structure directing insemination and female tissue interactions. Pairing magnetic resonance imaging 3D reconstruction with corresponding histology effectively studies functional anatomy.DATA AVAILABILITY STATEMENT : The MRI data that support the findings of this study are openly available in Morphosource at https://www.morphosource.org/reference number S30335.SUPPORTING INFORMATION : Figure S1. Correspondence between proximal glans tissue compartment histological staining and MRI. (a) Milligan's trichrome section: dense collagen tissue (DC), spongiform tissue (Sp), elastin-rich tissues (E), sulcus spermaticus (SS) note the groove opening is a histological processing artifact, smooth muscle fiber bundles (SM). Scale bar = 2 mm. (b) MRI dotted line traces: epithelia (pink), dense collage tissues (blue), spongiform tissues (purple), elastin-rich tissues (green), sulcus spermaticus (red), and smooth muscle fiber bundles (yellow).University of Pretoriahttp://wileyonlinelibrary.com/journal/jmorhj2021Anatomy and PhysiologyParaclinical Science