Exposure of a tendon extracellular matrix to synovial fluid triggers endogenous and engrafted cell death: A mechanism for failed healing of intrathecal tendon injuries

Aim: The purpose of this study was to investigate the effect of normal synovial fluid (SF) on exposed endogenous tendon-derived cells (TDC) and engrafted mesenchymal stem cells (MSCs) within the tendon extracellular matrix. Methods: Explants from equine superficial digital flexor (extra-synovial) and deep digital flexor tendons (DDFT) from the compressed, intra-synovial and the tensile, extra-synovial regions were cultured in allogeneic or autologous SF-media. Human hamstring explants were cultured in allogeneic SF. Explant viability was assessed by staining. Proliferation of equine monolayer MSCs and TDCs in SF-media and co-culture with DDFT explants was determined by alamarblue®. Non-viable Native Tendon matrices (NNTs) were re-populated with MSCs or TDCs and cultured in SF-media. Immunohistochemical staining of tendon sections for the apoptotic proteins caspase-3, -8 and -9 was performed. Results: Contact with autologous or allogeneic SF resulted in rapid death of resident tenocytes in equine and human tendon. SF did not affect the viability of equine epitenon cells, or of MSCs and TDCs in monolayer or indirect explant co-culture. MSCs and TDCs, engrafted into NNTs, died when cultured in SF. Caspase-3, -8 and -9 expression was greatest in SDFT explants exposed to allogeneic SF. Conclusions: The efficacy of cells administered intra-synovially for tendon lesion repair is likely to be limited, since once incorporated into the matrix, cells become vulnerable to the adverse effects of SF. These observations could account for the poor success rate of intra-synovial tendon healing following damage to the epitenon and contact with SF, common with most soft tissue intra-synovial pathologies

Fast radiative transfer using monochromatic look-up tables

AbstractLine-by-line (LBL) methods of numerically solving the equations of radiative transfer can be inhibitingly slow. Operational trace gas retrieval schemes generally require much faster output than current LBL radiative transfer models can achieve. One option to speed up computation is to precalculate absorption cross sections for each absorbing gas on a fixed grid and interpolate. This work presents a general method for creating, compressing, and validating a set of individual look-up tables (LUTs) for the 11 most abundant trace gases to use the Reference Forward Model (RFM) to simulate radiances observed by the Infrared Atmospheric Sounding Interferometer (IASI) at a more operational pace. These LUTs allow the RFM to generate radiances more than 20 times faster than LBL mode and were rigorously validated for 80 different atmospheric scenarios chosen to represent variability indicative of Earth׳s atmosphere. More than 99% of all IASI simulated spectral channels had LUT interpolation errors of brightness temperature less than 0.02K, several factors below the IASI noise level. Including a reduced spectral grid for radiative transfer speed up the computation by another factor of six at the expense of approximately doubling interpolation errors, still factors below IASI noise. Furthermore, a simple spectral compression scheme based upon linear interpolation is presented, which reduced the total LUT file size from 120Gbytes to 5.6Gbytes; a compression to just 4.4% of the original. These LUTs are openly available for use by the scientific community, whether using the RFM or to be incorporated into any forward model

Procjena fizikalnih parametrizacija u WRF modelu prilikom simuliranja značajnih obilnih oborina nad područjem indijskog monsuna

In this paper the performance of Weather Research and Forecasting (WRF) model for simulation of heavy rainfall events in presence of monsoon depressions over the Indian monsoon region is investigated with different physics options. A number of experiments for forecasts up to 72 hours are performed with two nested domains at the resolution of 45 km and 15 km respectively. The study shows that WRF model is sensitive to the choice of convective scheme. Betts-Miller-Janjic (BMJ) cumulus scheme is found to produce better results compared to other cumulus schemes for the Indian monsoon region. The model is capable of capturing the movement of the monsoon depression with a lead time of 72 hours. The model is expected to be very useful for forecasting of rainfall and depression tracks in short range time scales over Indian monsoon region.U radu se ispituju performanse WRF modela pri simuliranju obilnih oborina na području indijskog monsuna u vrijeme monsunske depresije za različite odabire fizikalnih shema. Napravljen je veći broj prognostičkih eksperimenata u trajanju do 72 sata, s dvije ugniježđene domene s rezolucijama od 45 km i 15 km. Studija pokazuje da je WRF model osjetljiv na izbor konvektivne sheme. Za područje indijskog monsuna Betts-Miller-Janjic (BMJ) kumulusna shema daje bolje rezultate u odnosu na druge kumulusne sheme. Model je uspio uhvatiti pomicanje monsunske depresije u trajanju do 72 sata. Model može biti vrlo koristan za područje indijskog monsuna u kratkoročnim prognozama prognozu oborine i putanja monsunske depresije

A new scheme for sulphur dioxide retrieval from IASI measurements: application to the Eyjafjallajökull eruption of April and May 2010

A new optimal estimation algorithm for the retrieval of sulphur dioxide (SO<sub>2</sub>) has been developed for the Infrared Atmospheric Sounding Interferometer (IASI) using the channels between 1000–1200 and 1300–1410 cm<sup>−1</sup>. These regions include the two SO<sub>2</sub> absorption bands centred at about 8.7 and 7.3 μm (the ν<sub>1</sub> and ν<sub>3</sub> bands respectively). The retrieval assumes a Gaussian SO<sub>2</sub> profile and returns the SO<sub>2</sub> column amount in Dobson units and the altitude of the plume in millibars (mb). Forward modelled spectra (against which the measurements are compared) are based on the Radiative Transfer for TOVS (RTTOV) code. In our implementation RTTOV uses atmospheric profiles from European Centre for Medium-Range Weather Forecasts (ECMWF) meteorological data. The retrieval includes a comprehensive error budget for every pixel derived from an error covariance matrix that is based on the SO<sub>2</sub>-free climatology of the differences between the IASI and forward modelled spectra. The IASI forward model includes the ability to simulate a cloud or ash layer in the atmosphere. This feature is used to illustrate that: (1) the SO<sub>2</sub> retrieval is not affected by underlying cloud but is affected if the SO<sub>2</sub> is within or below a cloud layer; (2) it is possible to discern if ash (or other atmospheric constituents not considered in the error covariance matrix) affects the retrieval using quality control based on the fit of the measured spectrum by the forward modelled spectrum. In this work, the algorithm is applied to follow the behaviour of SO<sub>2</sub> plumes from the Eyjafjallajökull eruption during April and May 2010. From 14 April to 4 May (during Phase I and II of the eruption) the total amount of SO<sub>2</sub> present in the atmosphere, estimated by IASI measurements, is generally below 0.02 Tg. During the last part of the eruption (Phase III) the values are an order of magnitude higher, with a maximum of 0.18 Tg measured on the afternoon of 7 May

Development of a Cartilage Oligomeric Matrix Protein Neo-Epitope Assay for the Detection of Intra-Thecal Tendon Disease

The diagnosis of tendon injury relies on clinical signs and diagnostic imaging but imaging is subjective and does not always correlate with clinical signs. A molecular marker would potentially offer a sensitive and specific diagnostic tool that could also provide objective assessment of healing for the comparison of different treatments. Cartilage Oligomeric Matrix Protein (COMP) has been used as a molecular marker for osteoarthritis in humans and horses but assays for the protein in tendon sheath synovial fluids have shown overlap between horses affected by tendinopathy and controls. We hypothesized that quantifying a COMP neoepitope would be more discriminatory of injury. COMP fragments were purified from synovial fluids of horses with intra-thecal tendon injuries and media from equine tendon explants, and mass spectrometry of a consistent and abundant fragment revealed a ~100 kDa COMP fragment with a new N-terminus at the 78th amino-acid (NH2-TPRVSVRP) located just outside the junctional region of the protein. A competitive inhibition ELISA based on a polyclonal antibody raised to this sequence yielded more than a 10-fold rise in the mean neoepitope levels for tendinopathy cases compared to controls (5.3 ± 1.3 µg/mL (n = 7) versus 58.8 ± 64.3 µg/mL (n = 13); p = 0.002). However, there was some cross-reactivity of the neoepitope polyclonal antiserum with intact COMP, which could be blocked by a peptide spanning the neoepitope. The modified assay demonstrated a lower concentration but a significant > 500-fold average rise with tendon injury (2.5 ± 2.2 ng/mL (n = 6) versus 1029.8 ± 2188.8 ng/ml (n = 14); p = 0.013). This neo-epitope assay therefore offers a potentially useful marker for clinical use

Lentiviral vector transduction of spermatozoa as a tool for the study of early development

Spermatozoa and lentiviruses are two of nature’s most efficient gene delivery vehicles. Both can be genetically modified and used independently for the generation of transgenic animals or gene transfer/therapy of inherited disorders. Here we show that mature spermatozoa can be directly transduced with various pseudotyped lentiviral vectors and used in in vitro fertilisation studies. Lentiviral vectors encoding Green Fluorescent Protein (GFP) were shown to be efficiently processed and expressed in sperm. When these transduced sperm were used in in vitro fertilisation studies, GFP expression was observed in arising blastocysts. This simple technique of directly transducing spermatozoa has potential to be a powerful tool for the study of early and pre-implantation development and could be used as a technique in transgenic development and vertical viral transmission studies

Procjena fizikalnih parametrizacija u WRF modelu prilikom simuliranja značajnih obilnih oborina nad područjem indijskog monsuna

In this paper the performance of Weather Research and Forecasting (WRF) model for simulation of heavy rainfall events in presence of monsoon depressions over the Indian monsoon region is investigated with different physics options. A number of experiments for forecasts up to 72 hours are performed with two nested domains at the resolution of 45 km and 15 km respectively. The study shows that WRF model is sensitive to the choice of convective scheme. Betts-Miller-Janjic (BMJ) cumulus scheme is found to produce better results compared to other cumulus schemes for the Indian monsoon region. The model is capable of capturing the movement of the monsoon depression with a lead time of 72 hours. The model is expected to be very useful for forecasting of rainfall and depression tracks in short range time scales over Indian monsoon region.U radu se ispituju performanse WRF modela pri simuliranju obilnih oborina na području indijskog monsuna u vrijeme monsunske depresije za različite odabire fizikalnih shema. Napravljen je veći broj prognostičkih eksperimenata u trajanju do 72 sata, s dvije ugniježđene domene s rezolucijama od 45 km i 15 km. Studija pokazuje da je WRF model osjetljiv na izbor konvektivne sheme. Za područje indijskog monsuna Betts-Miller-Janjic (BMJ) kumulusna shema daje bolje rezultate u odnosu na druge kumulusne sheme. Model je uspio uhvatiti pomicanje monsunske depresije u trajanju do 72 sata. Model može biti vrlo koristan za područje indijskog monsuna u kratkoročnim prognozama prognozu oborine i putanja monsunske depresije