Evaluation of daily changes of Intraocular pressure in glaucomatous patients with modified diurnal tension curve versus water drinking test

Background Glaucoma is a chronic optic neuropathy characterized by the excavation of the optic disc due to atrophy of the retinal ganglion cells. A progression of such atrophy leads to reduction of the visual field and eventually to the loss of sight at the end-stage of the disease, Glaucoma is the second leading cause of blindness worldwide Objectives To study the correlation between intraocular pressure (IOP) fluctuation during water drinking test (WDT) and the IOP fluctuation of modified diurnal tension curve (mDTC) in glaucomatous eyes Patients and Methods Fifty participants (24 males and 26 females) were recruited in this prospective study; forty participants with known Primary Open Angle Glaucoma and the other ten participants with non- glaucomatous healthy eyes which served as control. Patients attending the outpatient clinic at Al-Demerdash Hospital and Cairo Fatemic Hospital from October 2018 to March 2019 were prospectively recruited. Four IOP measurements were taken at 8:00 am, 12:00 pm, 4:00 pm and 8:00 pm which represented the mDTC, while WDT was represented by a single measurement of IOP before ingestion of one liter of water over five minutes, followed by three IOP measurements after ingestion of this amount of water at thirty minute intervals. Results Distribution of the studied participants as regards Age and sex: 50 participants were included in the this study. 40 presented the case group (20 males and 20 females) and the mean age of the case group was 54.7 years, 10 presented the control group(4 males and 6 females) and the mean age of the control group was 51.2years. 59% of participants had a peak IOP at 8:00 am, while 10% had a peak IOP at 12:00 pm, 6% at 4:00 pm and 25% of the participants had IOP peak at 8:00 pm during the mDTC. In the WDT, 96% of the participants had a peak IOP after 30 minutes of ingesting one liter of water, while 4% had a peak IOP after 60 minutes. None of the participants had IOP peak after 90 minutes of ingesting one liter of water.. The IOP fluctuations detected during the WDT were significantly correlated to fluctuations observed during the mDTC. Conclusion The data of this study suggested that WDT can be used as a useful provocative test for the detection of the diurnal IOP peaks and fluctuation observed in the glaucoma patients.

Modelling rein tension during riding sessions using the generalised additive modelling technique

General additive modelling (GAM-modelling) is an exploratory technique that can be used on longitudinal (time series) data, e.g. rein tension, over a period of time. The aim was to apply GAM-modelling to investigate changes in rein tension during a normal flatwork training session. Six riders each rode two or three of their horses (n=17 horses) during a normal flatwork/dressage training session with video recordings and rein tension measurements (128 Hz). Training sessions were classified according to rider position, stride length and whether horses were straight, bent to the left or bent to the right. The rein tension data were split into strides and for each stride minimal (MIN) and maximal (MAX) rein tension were determined and the area under the rein tension curve (AUC) was calculated. Using data on a contact the three outcome variables MIN, MAX and AUC rein tension were modelled by horse and rein (left/right), and time within the session was modelled as a smooth function. Two additional sets of models were constructed; one set using data within-rein with gait as a fixed effect and one set with rein and gait as fixed effects. Mean ± standard deviation values were MIN: 8.0±7.7 N, AUC: 180±109 Ns, and MAX: 49±31 N. GAM-modelling extracted visually interpretable information from the originally chaotic rein tension signals. Modelled data suggest that MIN, AUC and MAX follow the same pattern within horse. In general, rein tension was lowest in walk, intermediate in trot and highest in canter. Evaluating the entire ride, 12/17 horses systematically showed higher tension in the right rein. It is concluded that GAM-models may be useful for detecting patterns through time in biomechanical data.

Analysis of yarn tension based on yarn demand variation on a tricot knitting machine

To date, the trend in the development of knitting promotes higher requirements for warp tension control, and the fluctuation of knitting warp finally comes down to the imbalance between yarn demand and feed while forming every loop. According to warp knitting machine characteristics, four typical points are chosen to calculate the value of yarn demand, and in this way a model is built to obtain and plot the overall change trend in yarn demand in one knitting cycle. Combined with the theoretical tension curve calculated based on the yarn demand and the measured one, it is verified as coincident. The model is useful for analyzing the factors causing warp dynamic tension variation, and lays the groundwork for accurate active tension compensation.

The length–tension curve in muscle depends on lattice spacing

Classic interpretations of the striated muscle length–tension curve focus on how force varies with overlap of thin (actin) and thick (myosin) filaments. New models of sarcomere geometry and experiments with skinned synchronous insect flight muscle suggest that changes in the radial distance between the actin and myosin filaments, the filament lattice spacing, are responsible for between 20% and 50% of the change in force seen between sarcomere lengths of 1.4 and 3.4 µm. Thus, lattice spacing is a significant force regulator, increasing the slope of muscle's force–length dependence.