Telemetry receiver

Communications system maintains phase lock of weak telemetry signals with a minimal expenditure of power and bandwidth. An estimate of the frequency variation as a function of time is used to achieve coherent phase demodulation

ANISAP: A three-dimensional finite element program for laminated composites subjected to mechanical loading

ANISAP is a 3-D finite element FORTRAN 77 computer code for linear elastic, small strain, analysis of laminated composites with arbitrary geometry including free edges and holes. Individual layers may be isotropic or transversely isotropic in material principal coordinates; individual layers may be rotated off-axis about a global z-axis. The laminate may be a hybrid. Three different isoparametric elements, variable order of gaussian integration, calculation of stresses at element boundaries, and loading by either nodal displacement of forces are included in the program capability. Post processing capability includes failure analysis using the tensor polynominal failure criterion

Estimating sowing and harvest dates based on the Asian summer monsoon

Sowing and harvest dates are a significant source of uncertainty within crop models, especially for regions where high-resolution data are unavailable or, as is the case in future climate runs, where no data are available at all. Global datasets are not always able to distinguish when wheat is grown in tropical and subtropical regions, and they are also often coarse in resolution. South Asia is one such region where large spatial variation means higher-resolution datasets are needed, together with greater clarity for the timing of the main wheat growing season. Agriculture in South Asia is closely associated with the dominating climatological phenomenon, the Asian summer monsoon (ASM). Rice and wheat are two highly important crops for the region, with rice being mainly cultivated in the wet season during the summer monsoon months and wheat during the dry winter. We present a method for estimating the crop sowing and harvest dates for rice and wheat using the ASM onset and retreat. The aim of this method is to provide a more accurate alternative to the global datasets of cropping calendars than is currently available and generate more representative inputs for climate impact assessments. We first demonstrate that there is skill in the model prediction of monsoon onset and retreat for two downscaled general circulation models (GCMs) by comparing modelled precipitation with observations. We then calculate and apply sowing and harvest rules for rice and wheat for each simulation to climatological estimates of the monsoon onset and retreat for a present day period. We show that this method reproduces the present day sowing and harvest dates for most parts of India. The application of the method to two future simulations demonstrates that the estimated sowing and harvest dates are successfully modified to ensure that the growing season remains consistent with the internal model climate. The study therefore provides a useful way of modelling potential growing season adaptations to changes in future climate

Day to Day Variability of Dynamic Knee Joint Stability in Healthy Individuals

The cause of osteoarthritis remains unknown; however abnormal joint mechanics are speculated to be an initiating factor [1]. Relating the Finite Helical Axis (FHA) to joint health may provide a means of predicting risk of joint degeneration [2]. To study dynamic knee joint stability using FHA and electromyography (EMG), it is valuable to quantify the day to day variance of these measures in a healthy population. It was hypothesized that there would be no statistically significant differences in FHA parameters or muscle patterns between days for healthy individuals. Three healthy females with intact anterior cruciate ligaments were recruited and tested 3 times during one week. Three-dimensional data for FHA determination was collected from reflective skin markers placed on each lower extremity (3 markers/segment) using an 8-camera (120 Hz) video motion capture system (Motion Analysis Corp.). A 16-channel EMG system recorded muscle activation patterns from 6 major muscles of the leg. Each subject performed two dynamic tasks: unconstrained knee flexion and extension while seated, and a single leg squat and rise. Data was analyzed using in house programs written in Matlab 7.1 (Mathworks Inc.). Four FHA parameters were described: location, translation, orientation and dispersion [2]. Muscle activity patterns were quantified using a wavelet analysis approach [3]. Due to the small sample size, a non-parametric Friedman’s test was used to detect differences in dynamic knee joint stability between days (p=0.05). Significant differences (p=0.028) were found for the extension phase of the squat in the contra lateral legs for location y, which describes the anterior/posterior location of the FHA in the knee. No significant differences were detected for any other FHA or EMG parameters. This finding suggests that the y location of the FHA during the extension phase of the squat task changes across days, and must be carefully interpreted in future studies

MRI-Based Knee Joint Laxity Measure in Healthy Individuals

A functional MRI based knee joint laxity device was developed by the current research group to enable three-dimensional (3D) evaluation of change in ligament length as a function of loading [1]. Previous studies have used the knee loading apparatus (KLA) to quantify knee joint laxity in the dominant leg of healthy individuals [1]; however anterior laxity of the knee is reported clinically as a left-right difference, and not absolute values [2]. Therefore, the purpose of this study was to quantify side-to-side differences in knee joint laxity using the KLA in a healthy population. It was hypothesized that there would be no statistically significant differences in knee joint laxity between legs for healthy individuals. One healthy female with an intact anterior cruciate ligament was recruited and tested 3 times during the span of 10 days. Magnetic Resonance (MR) imaging was used in conjunction with the KLA to obtain images of the knee joint geometry during an unloaded state and at an anterior load of 133 N. Sagittal images of the knee were manually digitized using SliceOmatic (Tomovision) to obtain 3D volumes of the femur and tibia. The displacement of the tibia at 133N was obtained from the 3D joint position of the femur relative to the tibia, specifically anterior displacement of the tibia [1]. Due to complications with data collection, results are only available for day 2 for the right leg, and days 1 and 3 for the left leg. The anterior displacement of the tibia under an anterior load of 133N was 1.29 mm for the right leg, and 0.62 ± 0.42 mm for the left leg. Due to the sample size of 1, statistical analysis was not performed. This is preliminary data; future studies will increase the number of subjects and collect data at multiple load levels

Modulation of neutrophil function by the tripeptide feG

BACKGROUND: Neutrophils are critical in the defense against potentially harmful microorganisms, but their excessive and inappropriate activation can contribute significantly to tissue damage and a worsening pathology. Through the release of endocrine factors submandibular glands contribute to achieving a balance in neutrophil function by modulating the state of activation and migratory potential of circulating neutrophils. A putative hormonal candidate for these effects on neutrophils was identified as a heptapeptide named submandibular gland peptide T (SGP-T; sequence = TDIFEGG). Since the tripeptide FEG, derived from SGP-T, and its D-amino acid analogue feG had similar inhibitory effects on inflammatory reactions, we investigated the effects of feG on human and rat neutrophil function. RESULTS: With human neutrophils feG had no discernible effect on oxidative burst or phagocytosis, but in picomolar amounts it reduced PAF-induced neutrophil movement and adhesion, and the binding of CD11b by 34% and that of CD16b close to control values. In the rat feG (10(-11)M) reduced the binding of CD11b and CD16 antibodies to PAF-stimulated circulating neutrophils by 35% and 43%, respectively, and at 100 micrograms/kilograms intraperitoneally feG reduced neutrophil in vivo migration by 40%. With ovalbumin-sensitized rats that were challenged with antigen, feG inhibited binding of antibodies against CD16b but not CD11b, on peritoneal leukocytes. CONCLUSIONS: The inhibitory effect of feG on neutrophil movement may be mediated by alterations in the co-stimulatory molecules CD11b and CD16

South Asia river-flow projections and their implications for water resources

South Asia is a region with a large and rising population, a high dependence on water intense industries, such as agriculture and a highly variable climate. In recent years, fears over the changing Asian summer monsoon (ASM) and rapidly retreating glaciers together with increasing demands for water resources have caused concern over the reliability of water resources and the potential impact on intensely irrigated crops in this region. Despite these concerns, there is a lack of climate simulations with a high enough resolution to capture the complex orography, and water resource analysis is limited by a lack of observations of the water cycle for the region. In this paper we present the first 25 km resolution regional climate projections of river flow for the South Asia region. Two global climate models (GCMs), which represent the ASM reasonably well are downscaled (1960–2100) using a regional climate model (RCM). In the absence of robust observations, ERA-Interim reanalysis is also downscaled providing a constrained estimate of the water balance for the region for comparison against the GCMs (1990–2006). The RCM river flow is routed using a river-routing model to allow analysis of present-day and future river flows through comparison with available river gauge observations. We examine how useful these simulations are for understanding potential changes in water resources for the South Asia region. In general the downscaled GCMs capture the seasonality of the river flows but overestimate the maximum river flows compared to the observations probably due to a positive rainfall bias and a lack of abstraction in the model. The simulations suggest an increasing trend in annual mean river flows for some of the river gauges in this analysis, in some cases almost doubling by the end of the century. The future maximum river-flow rates still occur during the ASM period, with a magnitude in some cases, greater than the present-day natural variability. Increases in river flow could mean additional water resources for irrigation, the largest usage of water in this region, but has implications in terms of inundation risk. These projected increases could be more than countered by changes in demand due to depleted groundwater, increases in domestic use or expansion of water intense industries. Including missing hydrological processes in the model would make these projections more robust but could also change the sign of the projections

On the motion of a classical charged particle

We show that the Lorentz-Dirac equation is not an unavoidable consequence of energy-momentum conservation for a point charge. What follows solely from conservation laws is a less restrictive equation already obtained by Honig and Szamosi. The latter is not properly an equation of motion because, as it contains an extra scalar variable, it does not determine the future evolution of the charge. We show that a supplementary constitutive relation can be added so that the motion is determined and free from the troubles that are customary in Lorentz-Dirac equation, i. e. preacceleration and runaways

Post COP26: does the 1.5°C climate target remain alive?

One of the COP26 aims was to keep 1.5°C within reach by asking countries to come forward with ambitious year 2030 emission reductions targets to further pursue the necessary action to meet the Paris climate targets. We assess the mean global temperature rise given the updated year 2030 emission pledges in the context of future emission pathways considered by the international scientific community. Overall, we find current pledges are not consistent with a likely meeting of 1.5°C this century without overshoot. Meeting the 1.5°C goal in 2100 post overshoot given the pledges remains feasible, but urgent action is required to ensure pledges are met and policies are in place for the very deep and rapid emission reductions that are required post 2030