16 research outputs found

    Evaluation of Methods for Semantic Segmentation of Endoscopic Images

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    We examined multiple semantic segmentation methods, which consider the information contained in endoscopic images at different levels of abstraction in order to predict semantic segmentation masks. These segmentations can be used to obtain position information of surgical instruments in endoscopic images, which is the foundation for many computer assisted systems, such as automatic instrument tracking systems. The methods in this paper were examined and compared in regard to their accuracy, effort to create the data set, and inference time. Of all the investigated approaches, the LinkNet34 encoder-decoder network scored best, achieving an Intersection over Union score of 0.838 with an inference time of 30.25 ms on a 640 x 480 pixel input image with a NVIDIA GTX 1070Ti GPU

    Photometric determination of the mass accretion rates of pre-main sequence stars. III. Results in the Large Magellanic Cloud

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    We present a multi-wavelength study of three star forming regions, spanning the age range 1-14 Myr, located between the 30 Doradus complex and supernova SN1987A in the Large Magellanic Cloud (LMC). We reliably identify about 1000 pre-main sequence (PMS) star candidates actively undergoing mass accretion and estimate their stellar properties and mass accretion rate (Macc). Our measurements represent the largest Macc dataset of low-metallicity stars presented so far. As such, they offer a unique opportunity to study on a statistical basis the mass accretion process in the LMC and, more in general, the evolution of the mass accretion process around low-metallicity stars. We find that the typical \dot{M} of PMS stars in the LMC is higher than for galactic PMS stars of the same mass, independently of their age. Taking into account the caveats of isochronal age and \dot{M} estimates, the difference in Macc between the LMC and our Galaxy appears to be about an order of magnitude. We review the main mechanisms of disk dispersal and find indications that typically higher Macc are to be expected in low-metallicity environments. However, many issues of this scenario need to be clarified by future observations and modeling. We also find that, in the mass range 1-2 M_sun, the Macc of PMS stars in the LMC increases with stellar mass as \dot{M}acc\proptoM^b, with b \approx1, i.e. slower than the second power low found for galactic PMS stars in the same mass regime.Comment: 21 pages, 10 figures, 5 tables; MNRAS 201

    Diet or exercise, or both, for weight reduction in women after childbirth

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    Background: Weight retention after pregnancy may contribute to obesity. It is known that diet and exercise are recommended components of any weight loss programme in the general population. However, strategies to achieve healthy body weight among postpartum women have not been adequately evaluated. Objectives: The objectives of this review were to evaluate the effect of diet, exercise or both for weight reduction in women after childbirth, and to assess the impact of these interventions on maternal body composition, cardiorespiratory fitness, breastfeeding performance and other child and maternal outcomes.: Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2012) and LILACS (31 January 2012). We scanned secondary references and contacted experts in the field. We updated the search of the Cochrane Pregnancy and Childbirth Group's Trials Register on 30 April 2013 and added the results to the awaiting classification section of the review. Selection criteria: All published and unpublished randomised controlled trials (RCTs) and quasi‐randomised trials of diet or exercise or both, among women during the postpartum period. Data collection and analysis: Both review authors independently assessed trial quality and extracted data. Results are presented using risk ratio (RR) for categorical data and mean difference (MD) for continuous data. Data were analysed with a fixed‐effect model. A random‐effects model was used in the presence of heterogeneity. Main results: Fourteen trials were included, but only 12 trials involving 910 women contributed data to outcome analysis. Women who exercised did not lose significantly more weight than women in the usual care group (two trials; n = 53; MD ‐0.10 kg; 95% confidence interval (CI) ‐1.90 to 1.71). Women who took part in a diet (one trial; n = 45; MD ‐1.70 kg; 95% CI ‐2.08 to ‐1.32), or diet plus exercise programme (seven trials; n = 573; MD ‐1.93 kg; 95% CI ‐2.96 to ‐0.89; random‐effects, T² = 1.09, I² = 71%), lost significantly more weight than women in the usual care group. There was no difference in the magnitude of weight loss between diet alone and diet plus exercise group (one trial; n = 43; MD 0.30 kg; 95% CI ‐0.06 to 0.66). The interventions seemed not to affect breastfeeding performance adversely. Authors' conclusions: Evidence from this review suggests that both diet and exercise together and diet alone help women to lose weight after childbirth. Nevertheless, it may be preferable to lose weight through a combination of diet and exercise as this improves maternal cardiorespiratory fitness and preserves fat‐free mass, while diet alone reduces fat‐free mass. This needs confirmation in large trials of high methodological quality. For women who are breastfeeding, more evidence is required to confirm whether diet or exercise, or both, is not detrimental for either mother or baby

    Tick Salivary Sialostatin L Represses the Initiation of Immune Responses by Targeting IRF4-Dependent Transcription in Murine Mast Cells

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    Co-evolution of ticks and the vertebrate immune system has led to the development of immunosuppressive molecules that prevent immediate response of skin-resident immune cells to quickly fend off the parasite. Herein, we demonstrate that the tick-derived immunosuppressor sialostatin L restrains IL-9 production by mast cells while degranulation and IL-6 expression are both unaffected. In addition, the expression of IL-1β and IRF4 is strongly reduced in the presence of sialostatin L. Correspondingly, IRF4- or IL-1 receptor-deficient mast cells exhibit strong impairment in IL-9 production demonstrating the importance of IRF4 and IL-1 in the regulation of the Il9 locus in mast cells. Furthermore, IRF4 binds to the promoters of Il1b and Il9 suggesting that sialostatin L suppresses mast cell-derived IL-9 preferentially by inhibiting IRF4. In an experimental asthma model, mast cell-specific deficiency in IRF4 or administration of sialostatin L results in a strong reduction of asthma symptoms demonstrating the immunosuppressive potency of tick-derived molecules
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