3,310 research outputs found

    Dispersal of larval and juvenile seabream: Implications for Mediterranean marine protected areas

    Get PDF
    In the marine context, information about dispersal is essential for the design of networks of marine protected areas (MPAs). Generally, most of the dispersal of demersal fishes is thought to be driven by the transport of eggs and larvae in currents, with the potential contribution of dispersal in later life stages relatively minimal.Using otolith chemistry analyses, we estimate dispersal patterns across a spatial scale of approximately 180. km at both propagule (i.e. eggs and larvae) and juvenile (i.e. between settlement and recruitment) stages of a Mediterranean coastal fishery species, the two-banded seabream Diplodus vulgaris. We detected three major natal sources of propagules replenishing local populations in the entire study area, suggesting that propagule dispersal distance extends to at least 90. km. For the juvenile stage, we detected dispersal of up to 165. km. Our work highlights the surprising and significant role of dispersal during the juvenile life stages as an important mechanism connecting populations. Such new insights are crucial for creating effective management strategies (e.g. MPAs and MPA networks) and to gain support from policymakers and stakeholders, highlighting that MPA benefits can extend well beyond MPA borders, and not only via dispersal of eggs and larvae, but also through movement by juveniles

    Improvements in BepiColombo and JUICE radio science experiments with a multi-station tracking configuration for the reduction of Doppler noise

    Get PDF
    Radio science experiments for planetary geodesy mostly rely on measurements of the Doppler shift of microwave signals sent to a spacecraft by an Earth station, and retransmitted back coherently in phase to the same antenna (two-way link). The retransmitted signal can also be received by a different station in a listen-only configuration (three-way link). In state-of-the-art tracking systems, such as the ones will be used on the future ESA's missions JUICE and BepiColombo, the Doppler error budget is dominated by local noise sources arising at the ground-station, in particular tropospheric scintillation and unmodeled motions of the antenna's structure. In this work, a novel technique aimed at reducing these disturbances is analyzed, with particular emphasis on its benefits to BepiColombo's and JUICE's radio science experiments. The method, referred to as Time-Delay Mechanical-noise Cancellation (TDMC), relies on simultaneous two-way and three-way spacecraft tracking, the latter employing a stiffer listen-only antenna with better mechanical stability and located in a favorable dry region more immune to tropospheric noise. In fact, a proper linear combination of time-shifted observables from the two-way and three-way links can replace local noises of the two-way ground-station with those coming from the listen-only antenna, translating into increased accuracy of the final measurements, while preserving the original Doppler content. We show the results of covariance analyses performed with a multi-arc weighted least square estimator for the entire BepiColombo's Hermean phase and JUICE's flybys of Callisto. We compare the two solutions obtained with and without the application of the TDMC technique. For BepiColombo and JUICE radio science experiments, the two-way links are baselined from the 35-m DSA-3 (MalargĂĽe, Argentina) and the 34-m DSS 25 (Goldstone, California). For the three-way link, we select the 12-m Large Latin American Millimeter Array (LLAMA) antenna for three reasons: 1) its mechanical rigidity with respect to large beam-waveguide antennas, 2) its unique position in the extremely dry Puna de Atacama desert, that assures low tropospheric noise, and 3) its limited longitudinal separation from the two other ground-stations, granting sufficient common visibility time to perform the requested combination of the observables. Besides its noise-reduction effect, enabling unprecedented levels of accuracy on Doppler measurements, TDMC provides also a back-up for unique events: a crucial satellite flyby or a specific passage over a site of particular geophysical interest. Indeed, measurements become virtually independent of unfavorable meteorological conditions at the transmitting station

    Fundamental Limits of Low-Density Spreading NOMA with Fading

    Full text link
    Spectral efficiency of low-density spreading non-orthogonal multiple access channels in the presence of fading is derived for linear detection with independent decoding as well as optimum decoding. The large system limit, where both the number of users and number of signal dimensions grow with fixed ratio, called load, is considered. In the case of optimum decoding, it is found that low-density spreading underperforms dense spreading for all loads. Conversely, linear detection is characterized by different behaviors in the underloaded vs. overloaded regimes. In particular, it is shown that spectral efficiency changes smoothly as load increases. However, in the overloaded regime, the spectral efficiency of low- density spreading is higher than that of dense spreading

    Blocking CD248 molecules in perivascular stromal cells of patients with systemic sclerosis strongly inhibits their differentiation toward myofibroblasts and proliferation: A new potential target for antifibrotic therapy

    Get PDF
    Background: Fibrosis may be considered the hallmark of systemic sclerosis (SSc), the end stage triggered by different pathological events. Transforming growth factor-β (TGF-β) and platelet-derived growth factor BB (PDGF-BB) are profibrotic molecules modulating myofibroblast differentiation and proliferation, respectively. There is evidence linking CD248 with these two molecules, both highly expressed in patients with SSc, and suggesting that CD248 may be a therapeutic target for several diseases. The aim of this work was to evaluate the expression of CD248 in SSc skin and its ability to modulate SSc fibrotic process. Methods: After ethical approval was obtained, skin biopsies were collected from 20 patients with SSc and 10 healthy control subjects (HC). CD248 expression was investigated in the skin, as well as in bone marrow mesenchymal stem cells (MSCs) treated with TGF-β or PDGF-BB, by immunofluorescence, qRT-PCR, and Western blotting. Finally, in SSc-MSCs, the CD248 gene was silenced by siRNA. Results: Increased expression of CD248 was found in endothelial cells and perivascular stromal cells of SSc skin. In SSc-MSCs, the levels of CD248 and α-smooth muscle actin expression were significantly higher than in HC-MSCs. In both SSc- and HC-MSCs, PDGF-BB induced increased expression of Ki-67 when compared with untreated cells but was unable to modulate CD248 levels. After CD248 silencing, both TGF-β and PDGF-BB signaling were inhibited in SSc-MSCs. Conclusions: CD248 overexpression may play an important role in the fibrotic process by modulating the molecular target, leading to perivascular cells differentiation toward myofibroblasts and interfering with its expression, and thus might open a new therapeutic strategy to inhibit myofibroblast generation during SSc

    hMENA11a contributes to HER3-mediated resistance to PI3K inhibitors in HER2-overexpressing breast cancer cells.

    Get PDF
    Human Mena (hMENA), an actin regulatory protein of the ENA/VASP family, cooperates with ErbB receptor family signaling in breast cancer. It is overexpressed in high-risk preneoplastic lesions and in primary breast tumors where it correlates with HER2 overexpression and an activated status of AKT and MAPK. The concomitant overexpression of hMENA and HER2 in breast cancer patients is indicative of a worse prognosis. hMENA is expressed along with alternatively expressed isoforms, hMENA11a and hMENAΔv6 with opposite functions. A novel role for the epithelial-associated hMENA11a isoform in sustaining HER3 activation and pro-survival pathways in HER2-overexpressing breast cancer cells has been identified by reverse phase protein array and validated in vivo in a series of breast cancer tissues. As HER3 activation is crucial in mechanisms of cell resistance to PI3K inhibitors, we explored whether hMENA11a is involved in these resistance mechanisms. The specific hMENA11a depletion switched off the HER3-related pathway activated by PI3K inhibitors and impaired the nuclear accumulation of HER3 transcription factor FOXO3a induced by PI3K inhibitors, whereas PI3K inhibitors activated hMENA11a phosphorylation and affected its localization. At the functional level, we found that hMENA11a sustains cell proliferation and survival in response to PI3K inhibitor treatment, whereas hMENA11a silencing increases molecules involved in cancer cell apoptosis. As shown in three-dimensional cultures, hMENA11a contributes to resistance to PI3K inhibition because its depletion drastically reduced cell viability upon treatment with PI3K inhibitor BEZ235. Altogether, these results indicate that hMENA11a in HER2-overexpressing breast cancer cells sustains HER3/AKT axis activation and contributes to HER3-mediated resistance mechanisms to PI3K inhibitors. Thus, hMENA11a expression can be proposed as a marker of HER3 activation and resistance to PI3K inhibition therapies, to select patients who may benefit from these combined targeted treatments. hMENA11a activity could represent a new target for antiproliferative therapies in breast cancer

    Total knee revision arthroplasty: comparison between tibial tubercle osteotomy and quadriceps snip approach. Complication rate

    Get PDF
    BACKGROUND AND AIM OF THE WORK: The total knee arthroplasty (TKA) revision is not a second time of primary implant surgery but is a very complex issue for orthopedic surgeon. When local conditions make necessary a greater visualization, medial para-patellar access with quadriceps snip (QS) or the osteotomy of the tibial tuberosity (TTO) can be the solutions. This work aims to compare the quadriceps snip and the detachment of the tibial tubercle, focusing on possible complications. MATERIALS AND METHODS: At our institution, between January 2017 and February 2019 52 TKA revision for periprosthetic joint infection (PJI) or aseptic mobilization were performed. In 43 cases an extensive surgical approach was required: for patients with range of movement (ROM) 60\ub0 a QS was performed. Clinical and radiological follow-up was available for all the 43 cases. RESULTS: The data about clinical outcome in our study show that both groups have a positive trend in KSS score over time with similar ROM results. Two partial avulsions of patellar tendon during revision surgery were reported. Clinical outcome in both groups has shown good results at the end of follow-up with no post-operative incidence of complications. CONCLUSION: We can assert that both QS and TTO are good approach for TKA revision. Future studies will be needed to understand if preparatory ROM is a good way to decide which surgical approach to use.(www.actabiomedica.it)

    Capsular closure after hip arthroscopy: our experience

    Get PDF
    BACKGROUND AND AIM OF THE WORK: In the last decade, arthroscopic treatment of hip diseases has significantly spread and evolved and currently it represents the gold standard for the treatment of femoral- acetabular impingement. In the recent years, the function of the joint capsule (and therefore the results of an arthroscopic capsulotomy) has been hugely developed, opening a heated debate. The Literature is still torn about the need for a capsular suture, but more recent studies are more oriented in its execution at the end of the surgical procedure. According to these recent studies, the joint capsule performs an essential function of primary stability, and its closure is therefore necessary to restore the native anatomy and physiology. Nevertheless, capsular management remains a controversial topic. This is a retrospective study with the aim of assessing the influence of capsular suture on the patient's functional outcome in a cohort of patients with femoral-acetabular impingement arthroscopically treated. HYPOTHESIS: Our hypothesis is that an adequate capsular suture positively influences the patient's functional outcome. METHODS AND RESULTS: 50 patients treated with hip arthroscopy for femoral-acetabular impingement have been retrospectively enrolled at the Orthopaedic Clinic of Academic Hospital of Udine during a period of two-years (2017-2018); collected data have been analysed and compared with a retrospective model. Patients have been divided into two equivalent groups, 25 treated with capsular suture, 25 without performing the suture. Patient's post-operative functional outcome has been analysed using the modified Harris Hip Score (mHHS), the Non-Arthritic Hip Score (NAHS) and the Hip Outcome Score-Sport Scale (HOS-SS). The functional outcome in patients where capsular sutures were performed was better than in non-sutured patients, in all three analysed scales. CONCLUSIONS: Capsular suture with a single side-to-side stitch at the end of the procedure can positively influence the patient's functional outcome

    Subchondroplasty in the treatment of bone marrow lesions of the knee: Preliminary experience on first 15 patients

    Get PDF
    Purpose The aim of this prospective study was to assess the effectiveness in terms of pain relief and functional improvement of the Subchondroplasty procedure in the treatment of osteoarthritis-related bone marrow lesions (BMLs) of the knee. Methods The study included first 15 consecutive patients undergone to Subchon-droplasty procedure for the treatment of chronic degenerative BMLs in which previous conservative treatment have failed. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, Knee Injury and Osteoarthritis Outcome Scores (KOOS), and visual analog scale (VAS) pain scores were obtained preoperatively and at 1, 6, and 12 months of follow-up. Results WOMAC scores significantly improved from 39.7 \ub1 20.2 before surgery to 26.8 \ub1 16.1 at the 1-month follow-up (p = 0.045). A further significant improvement to 15.5 \ub1 12.7 (p = 0.02) and to 8.6 \ub1 3.1 (p <0.01) was obtained both at 6-month and at 1-year follow-up. KOOS scores improved significantly from 47.5 \ub1 16.6 before surgery to 65.4 \ub1 14.9 at 1 month (p = 0.013) and to 80.4 \ub1 15.1 at 6-month follow-up (p = 0.01). A further improvement to 85.6 \ub1 15.1 was recorded 1 year postoperatively, although nonsignificant. VAS score showed a significant improvement from 55.8 \ub1 20.5 preoperatively to 36.2 \ub1 16.9 at 1 month (p = 0.008) and to 18.2 \ub1 17.3 at 6-month follow-up (p = 0.005). This further improved to 12.8 \ub1 17.9 at 1-year follow-up, although not significantly. Conclusion Subchondroplasty procedure represents a safe and valid surgical option in the treatment of osteoarthritis-related BMLs of the knee, providing an improvement in terms of pain relief and functional recovery. Longer studies are required to evaluate how long these improvements may last. Level of Evidence Therapeutic case-series, Level IV study
    • …
    corecore