DiffObs: Generative Diffusion for Global Forecasting of Satellite Observations

This work presents an autoregressive generative diffusion model (DiffObs) to predict the global evolution of daily precipitation, trained on a satellite observational product, and assessed with domain-specific diagnostics. The model is trained to probabilistically forecast day-ahead precipitation. Nonetheless, it is stable for multi-month rollouts, which reveal a qualitatively realistic superposition of convectively coupled wave modes in the tropics. Cross-spectral analysis confirms successful generation of low frequency variations associated with the Madden--Julian oscillation, which regulates most subseasonal to seasonal predictability in the observed atmosphere, and convectively coupled moist Kelvin waves with approximately correct dispersion relationships. Despite secondary issues and biases, the results affirm the potential for a next generation of global diffusion models trained on increasingly sparse, and increasingly direct and differentiated observations of the world, for practical applications in subseasonal and climate prediction.Comment: Published as a workshop paper at "Tackling Climate Change with Machine Learning", ICLR 202

Učinci odvraćajućih aktivnosti na elektromiografsku amplitudu i središnju frekvenciju

The purpose of this study was to examine the effects of diverting activities on electromyographic amplitude and mean frequency. On three separate occasions, eleven men and eight women performed two bouts of fifty consecutive maximal concentric isokinetic muscle actions of the dominant leg extensors. Between these bouts, the subjects either solved math problems, performed contralateral dynamic constant external resistance leg extensions, or rested quietly. During each muscle action, electromyographic signals were detected from the vastus lateralis, rectus femoris, and vastus medialis. The results indicated that neither the mental nor the physical diverting activities consistently affected the mean electromyographic amplitude and mean frequency values relative to the control visit of quiet resting. If mental or physical diverting activities affected muscle activation in the vastus lateralis, rectus femoris or vastus medialis, electromyographic amplitude and mean frequency values were not sensitive enough to detect it.Cilj je ovog istraživanja ispitati učinke odvraćajućih aktivnosti na amplitudu i prosječnu frekvenciju elektromiografskog signala. U tri odvojene situacije, jedanaest muškaraca i osam žena izvodilo je dvije serije od pedeset uzastopnih, maksimalnih, koncentričnih izokinetičkih mišićnih akcija ekstenzorima dominantne noge. Između serija, subjekti su ili rješavali matematičke probleme, izvodili kontralateralna dinamička opružanja s konstantnim vanjskim opterećenjem ili su se odmarali. Tijekom svake mišićne akcije bilježili su se elektromiografski signali u mišićima vastus lateralis, rectus femoris i vastus medialis. Rezultati su pokazali da ni psihičke ni fizičke odvraćajuće aktivnosti nisu konzistentno utjecale na prosječnu elektromiografsku amplitudu i frekvenciju. Ukoliko su mentalne ili fizičke odvraćajuće aktivnosti ipak nekako utjecale na mišićnu aktivaciju mišića vastus lateralis, rectus femoris ili vastus medialis, elektromiografske vrijednosti prosječne amplitude i frekvencije nisu bile dovoljno osjetljive da to otkriju

Tissue-engineered valved conduits in the pulmonary circulation

AbstractObjective: Bioprosthetic and mechanical valves and valved conduits are unable to grow, repair, or remodel. In an attempt to overcome these shortcomings, we have evaluated the feasibility of creating 3-leaflet, valved, pulmonary conduits from autologous ovine vascular cells and biodegradable polymers with tissue-engineering techniques. Methods: Endothelial cells and vascular medial cells were harvested from ovine carotid arteries. Composite scaffolds of polyglycolic acid and polyhydroxyoctanoates were formed into a conduit, and 3 leaflets (polyhydroxyoctanoates) were sewn into the conduit. These constructs were seeded with autologous medial cells on 4 consecutive days and coated once with autologous endothelial cells. Thirty-one days (±3 days) after cell harvesting, 8 seeded and 1 unseeded control constructs were implanted to replace the pulmonary valve and main pulmonary artery on cardiopulmonary bypass. No postoperative anticoagulation was given. Valve function was assessed by means of echocardiography. The constructs were explanted after 1, 2, 4, 6, 8, 12, 16, and 24 weeks and evaluated macroscopically, histologically, and biochemically. Results: Postoperative echocardiography of the seeded constructs demonstrated no thrombus formation with mild, nonprogressive, valvular regurgitation up to 24 weeks after implantation. Histologic examination showed organized and viable tissue without thrombus. Biochemical assays revealed increasing cellular and extracellular matrix contents. The unseeded construct developed thrombus formation on all 3 leaflets after 4 weeks. Conclusion: This experimental study showed that valved conduits constructed from autologous cells and biodegradable matrix can function in the pulmonary circulation. The progressive cellular and extracellular matrix formation indicates that the remodeling of the tissue-engineered structure continues for at least 6 months. (J Thorac Cardiovasc Surg 2000;119:732-40

The Influence of Sonographer Experience on Skeletal Muscle Image Acquisition and Analysis

The amount of experience with ultrasonography may influence measurement outcomes while images are acquired or analyzed. The purpose of this study was to identify the interrater reliability of ultrasound image acquisition and image analysis between experienced and novice sonographers and image analysts, respectively. Following a brief hands-on training session (2 h), the experienced and novice sonographers and analysts independently performed image acquisition and analyses on the biceps brachii, vastus lateralis, and medial gastrocnemius in a sample of healthy participants (n = 17). Test–retest reliability statistics were computed for muscle thickness (transverse and sagittal planes), muscle cross-sectional area, echo intensity and subcutaneous adipose tissue thickness. The results show that image analysis experience generally has a greater impact on measurement outcomes than image acquisition experience. Interrater reliability for measurements of muscle size during image acquisition was generally good–excellent (ICC2,1: 0.82–0.98), but poor–moderate for echo intensity (ICC2,1: 0.43–0.77). For image analyses, interrater reliability for measurements of muscle size for the vastus lateralis and biceps brachii was poor–moderate (ICC2,1: 0.48–0.70), but excellent for echo intensity (ICC2,1: 0.90–0.98). Our findings have important implications for laboratories and clinics where members possess varying levels of ultrasound experience

Polycomb Group Genes: Keeping Stem Cell Activity in Balance

Overexpression of Polycomb group genes is often associated with cancer development, whereas complete deletion results in loss of stem cell activity. New studies show that partial loss of function of Polycomb group genes enhances the activity of blood stem/progenitor cells

C-STICH2: emergency cervical cerclage to prevent miscarriage and preterm birth—study protocol for a randomised controlled trial

Abstract Background Cervical cerclage is a recognised treatment to prevent late miscarriage and pre-term birth (PTB). Emergency cervical cerclage (ECC) for cervical dilatation with exposed unruptured membranes is less common and the potential benefits of cerclage are less certain. A randomised control trial is needed to accurately assess the effectiveness of ECC in preventing pregnancy loss compared to an expectant approach. Methods C-STICH2 is a multicentre randomised controlled trial in which women presenting with cervical dilatation and unruptured exposed membranes at 16 + 0 to 27 + 6 weeks gestation are randomised to ECC or expectant management. Trial design includes 18 month internal pilot with embedded qualitative process evaluation, minimal data set and a within-trial health economic analysis. Inclusion criteria are ≥16 years, singleton pregnancy, exposed membranes at the external os, gestation 16 + 0–27 + 6 weeks, and informed consent. Exclusion criteria are contraindication to cerclage, cerclage in situ or previous cerclage in this pregnancy. Randomisation occurs via an online service in a 1:1 ratio, using a minimisation algorithm to reduce chance imbalances in key prognostic variables (site, gestation and dilatation). Primary outcome is pregnancy loss; a composite including miscarriage, termination of pregnancy and perinatal mortality defined as stillbirth and neonatal death in the first week of life. Secondary outcomes include all core outcomes for PTB. Two-year development outcomes will be assessed using general health and Parent Report of Children’s Abilities-Revised (PARCA-R) questionnaires. Intended sample size is 260 participants (130 each arm) based on 60% rate of pregnancy loss in the expectant management arm and 40% in the ECC arm, with 90% power and alpha 0.05. Analysis will be by intention-to-treat. Discussion To date there has been one small trial of ECC in 23 participants which included twin and singleton pregnancies. This small trial along with the largest observational study (n = 161) found ECC to prolong pregnancy duration and reduce deliveries before 34 weeks gestation. It is important to generate high quality evidence on the effectiveness of ECC in preventing pregnancy loss, and improve understanding of the prevalence of the condition and frequency of complications associated with ECC. An adequately powered RCT will provide the highest quality evidence regarding optimum care for these women and their babies. Trial registration ISRCTN Registry ISRCTN12981869 . Registered on 13th June 2018

Seismic Calibration Shots Conducted in 2009 in the Imperial Valley, Southern California, for the Salton Seismic Imaging Project (SSIP)

The Salton Seismic Imaging Project (SSIP) is a large-scale collaborative project with the goal of developing a detailed 3-D structural image of the Salton Trough (including both the Coachella and Imperial Valleys). The image will be used for earthquake hazard analysis, geothermal studies, and studies of plate-boundary transition from an ocean-ocean to a continent-continent plate-boundary. As part of SSIP, a series of calibration shots were detonated in June 2009 in the southern Imperial Valley for four specific reasons: (1) to measure peak particle velocity and acceleration at various distances from the shots, (2) to calibrate the propagation of energy through sediments of the Imperial Valley, (3) to test the effects of seismic energy on buried clay drainage pipes, which are abundant throughout the irrigated parts of the Salton Trough, and (4) to test the ODEX drilling technique, which uses a downhole casing hammer for a tight casing fit. Currently, we are using information obtained from the calibration shots to plan the data collection phase of the SSIP project. We have validated the use of ground-motion tables developed with Los Angeles Region Seismic Experiment (LARSE) data for use in the Imperial Valley and we have demonstrated that seismic energy from shots will not damage the drainage pipes used throughout the Salton Trough for irrigation