Deep learning explainability is often reached by gradient-based approaches that attribute the network output to perturbations of the input pixels. However, the relevance of input pixels may be ...difficult to relate to relevant image features in some applications, e.g. diagnostic measures in medical imaging. The framework described in this paper shifts the attribution focus from pixel values to user-defined concepts. By checking if certain diagnostic measures are present in the learned representations, experts can explain and entrust the network output. Being post-hoc, our method does not alter the network training and can be easily plugged into the latest state-of-the-art convolutional networks. This paper presents the main components of the framework for attribution to concepts, in addition to the introduction of a spatial pooling operation on top of the feature maps to obtain a solid interpretability analysis. Furthermore, regularized regression is analyzed as a solution to the regression overfitting in high-dimensionality latent spaces. The versatility of the proposed approach is shown by experiments on two medical applications, namely histopathology and retinopathy, and on one non-medical task, the task of handwritten digit classification. The obtained explanations are in line with clinicians’ guidelines and complementary to widely used visualization tools such as saliency maps.
Display omitted
•Feature attribution explains CNNs in terms of the input pixels.•The abstraction of feature attribution to higher level impacting factors is hard.•Concept attribution explains CNNs with high-level concepts such as clinical factors.•Nuclei pleomorphism is shown as a relevant factor in breast tumor classification.•Concept attribution can match clinical expectations to the interpretability of CNNs.
Galactic cosmic rays (CRs) inside the heliosphere are affected by solar modulation. To investigate this phenomenon and its underlying physical mechanisms, we have performed a data-driven analysis of ...the temporal dependence of the CR proton flux over the solar cycle. The modulation effect was modeled by means of stochastic simulations of cosmic particles in the heliosphere. The model was constrained using measurements of CR protons made by AMS-02 and PAMELA experiments on a monthly basis from 2006 to 2017. With a global statistical analysis of these data, we have determined the key model parameters governing CR diffusion, its dependence on the particle rigidity, and its evolution over the solar cycle. Our results span over epochs of solar minimum and solar maximum, as well as epochs with magnetic reversal and opposite polarities. Along with the evolution of the CR transport parameters, we study their relationship with solar activity proxies and interplanetary parameters. We find that the rigidity dependence of the parallel mean free path of CR diffusion shows a remarkable time dependence, indicating a long-term variability in the interplanetary turbulence that interchanges across different regimes over the solar cycle. The evolution of the diffusion parameters shows a delayed correlation with solar activity proxies, reflecting the dynamics of the heliospheric plasma, and distinct dependencies for opposite states of magnetic polarity, reflecting the influence of charge-sign-dependent drift in the CR modulation.
While the cultivated area of pollinator-dependent crops is increasing, pollinator availability is decreasing, leading to problems in many agroecosystems. For this reason, pollinator-dependent crop ...growers often rent beehives to support their pollination requirements to sustain fruit productivity. However, the efficiency of those pollination systems has not been extensively studied. Here, we compared the effect of "precision" pollination (i.e., application of pesticides coordinated with growers, audit of hives, dietary supplementation and individual distribution of hives) with conventional practices (i.e., pesticides applications without coordination with growers and no audit of hives, low maintenance of hives and hives distributed in large groups) on the mean level of pollination and fruit production and quality in blueberry crops. In nine blueberry fields, we measured bee visitation rate to flowers, fruit set, fruit firmness and fruit weight. On average, precision-pollinated plots had 70% more bee visits to flowers and produced 13% more fruits that were 12% heavier and 12% firmer than those obtained through conventional practices. These results showed that pollination efficiency could be improved if key management related to bee strength, distribution and health care are taken into account. Due to these results, we encourage growers and beekeepers to include precision pollination practices to both increase the productivity of blueberry fields and the wellbeing of honey bees within agroecosystems.
The term "immune privilege" was originally coined to describe the suppression of inflammatory responses within organs protected by anatomic barriers, ie, the eyes, brain, placenta, and testes. ...However, cellular and metabolic processes, which orchestrate immune responses, also control inflammation within these sites. Our current understanding of tolerogenic mechanisms has extended the definition of immune privilege to include hair follicles, the colon, and cancer. By catabolizing tryptophan, cells expressing the enzyme indoleamine-2,3-dioxygenase produce kynurenine metabolites, which orchestrate local and systemic responses to control inflammation, thus maintaining immune privilege. This review highlights the double-edged role played by the kynurenine pathway (KP), which establishes and maintains immune-privileged sites while contributing to cancer immune escape. The identification of the underlying molecular drivers of the KP in immune-privileged sites and in cancer is essential for the development of novel therapies to treat autoimmunity and cancer and to improve transplantation outcomes.
Summary
Background
Circulating microRNAs (miRNAs) may act as biomarkers of metabolic disturbances.
Objective
The aim of this study was to identify serum miRNAs signature of early insulin resistance ...in obese preschoolers.
Methods
Twelve obese children, aged 2–6 years, six insulin resistant (IR) and six controls were selected being age‐matched, sex‐matched and body mass index‐matched. Profiling of 179 circulating miRNAs, known to be widely expressed in the bloodstream, was investigated by quantitative polymerase chain reaction at fasting and 120 min following a standard oral glucose tolerance test (OGTT).
Results
Twenty‐one miRNAs were differentially regulated in IR obese preschoolers. miR‐200c‐3p, miR‐190a and miR‐95 were differently regulated both at fasting and 120 min after the OGTT. In controls, the fold changes of some miRNAs were correlated with Δglucose0‐120 (miR‐660, miR‐26b‐5p and miR‐22‐3p: p = 0.005 for all) and Δinsulin0‐120 (miR‐660 and miR‐22‐3p: p = 0.02 for both and miR‐423‐5p: p = 0.042). In IR patients, miR‐1 fold changes were correlated with Δglucose0‐120 (r = −0.786; p = 0.036) and Δinsulin0‐120 (r = −0.821; p = 0.023).
Conclusions
Our study identifies circulating miR‐200c‐3p, miR‐190a and miR‐95 as biomarkers of insulin resistance in obese preschoolers, being differentially regulated in IR patients both in fasting condition and after the OGTT. Expression of some circulating miRNAs seems reflecting glucose and insulin excursion following the OGTT differently in controls and IR obese preschoolers.
Endothelial-colony forming cells (ECFCs) can be readily expanded from human umbilical cord blood and can facilitate repair of endothelial injury. E-selectin and SDF-1α are produced following ...endothelial injury and can regulate endothelial progenitor homing. Mechanisms of vascular repair specific to the mode of injury have not been well described in homogenous cell populations such as ECFCs and are needed for development of more effective vascular repair strategies.
Lipopolysaccharide (LPS)-induced endotoxic injury to mature human umbilical vein endothelial cells (HUVEC) was compared with hypoxic and radiation injury. E-selectin expression in HUVEC cells is markedly increased (208-fold) following LPS-induced injury and facilitates increased ECFC adhesion and migration function in vitro. SDF-1α expression remains unchanged in LPS-treated HUVEC cells but increases more than 2 fold in fibroblasts undergoing similar endotoxic injury. SDF-1α induces expression of E-selectin ligands on ECFCs and facilitates greater E-selectin-mediated adhesion and migration of ECFCs in a CXCR4-dependent manner. Induction of E-selectin expression in HUVECs following hypoxic or radiation injury is negligible, however, while SDF-1α is increased markedly following hypoxia, highlighting injury-specific synergism between mediators of vascular repair.
E-selectin mediates adhesion and migration of ECFCs following endotoxic endothelial injury. SDF-1α augments E-selectin mediated ECFC adhesion and migration in a CXCR4-dependent manner.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
We have been monitoring, at high cadence, the photometric and spectroscopic evolution of VES 263 following the discovery in 2018 of a brightening labelled as event Gaia-18azl. VES 263 is so ...far a neglected emission-line object discovered in the 1960s on objective prism plates, tentatively classified as a semiregular AGB cool giant by automated analysis of ASASSN light curves. We have discovered that VES 263 is a bona fide massive pre-main-sequence object (∼12 M⊙), of the Herbig AeBe type. It is located at 1.68 ± 0.07 kpc distance, within the Cyg OB2 star-forming region, and it is highly reddened E(B − V) = 1.80 ± 0.05 by interstellar extinction. In quiescence, the spectral energy distribution is dominated by the ∼20 000 K photospheric emission from the central B1II star, and at λ ≥ 6 $\mu$m by emission from circumstellar warm dust (T ≤ 400 K). The 2018–19 eruption was caused by a marked brightening of the accretion disc around the B1II star as traced by the evolution with time of the integrated flux and the double-peaked profile of emission lines. At the peak of the eruption, the disc has a bulk temperature of ∼7500 K and a luminosity L ≥ 860 L⊙, corresponding to a mass accretion rate $\dot{M}$ ≥ 1.1 × 10−5 M⊙ yr−1. Spectroscopic signatures of possible bipolar jets (at −700 and +700 km s−1) of variable intensity are found. We have reconstructed from Harvard, Moscow, and Sonneberg photographic plates the photometric history of VES 263 from 1896 to 1995.
BVR
C
I
C photometry and low-, medium- and high-resolution echelle fluxed spectroscopy is presented and discussed for three faint, heavily reddened novae of the Fe ii-type which erupted in 2013. ...V1830 Nova Aql 2013 reached a peak V = 15.2 mag on 2013 Oct 30.3 ut and suffered from a huge E(B − V) ∼ 2.6 mag reddening. After a rapid decline, when the nova was ΔV = 1.7 mag below maximum, it entered a flat plateau where it remained for a month until solar conjunction prevented further observations. Similar values were observed for V556 Nova Ser 2013, that peaked near R
C ∼ 12.3 around 2013 Nov 25 and soon went lost in the glare of sunset sky. A lot more observations were obtained for V809 Nova Cep 2013, that peaked at V = 11.18 on 2013 Feb 3.6. The reddening is E(B − V) ∼ 1.7 and the nova is located within or immediately behind the spiral Outer Arm, at a distance of ∼6.5 kpc as constrained by the velocity of interstellar atomic lines and the rate of decline from maximum. While passing at t
3, the nova begun to form a thick dust layer that caused a peak extinction of ΔV > 5 mag, and took 125 d to completely dissolve. The dust extinction turned from neutral to selective around 6000 Å. Monitoring the time evolution of the integrated flux of emission lines allowed us to constrain the region of dust formation in the ejecta to be above the region of formation of O i 7774 Å and below that of Ca ii triplet. Along the decline from maximum and before the dust obscuration, the emission line profiles of Nova Cep 2013 developed a narrow component (FWHM = 210 km s−1) superimposed on to the much larger normal profile, making it a member of the so-far exclusive but growing club of novae displaying this peculiar feature. Constrains based on the optical thickness of the innermost part of the ejecta and on the radiated flux, place the origin of the narrow feature within highly structured internal ejecta and well away from the central binary.
Abstract Two vaccination programmes for infectious bursal disease (IBD) were compared in broiler chickens with maternal immunity, placed on two farms. A turkey herpes virus (HVT)-IBD vector vaccine ...was administered by the subcutaneous route, at the hatchery, into the chicks of farm A at the age of 1 day. On farm B, an attenuated intermediate live IBD vaccine was given orally at the ages of 17 and 24 days. The vaccine uptake was monitored via serology and bursa/body weight ratio evolution, as well as PCR-based viral IBDV detection in the bursa of Fabricius at various time points. It was also verified by an experimental very virulent IBDV challenge performed at the age of 30 days in birds transferred from the farms with appropriate control groups in a laboratory. An immunity gap was observed in birds from farm B between the decay of the passive and the rise of the active immunity based upon serological data. The level of protection against challenge is not possible to establish in this farm as the reduction of the bursa/body weight ratio observed could be due to the residual pathogenicity of the vaccine strain or the challenge as well. This immunity gap was not present on farm A showing higher serological titres at the ages of 26 and 45 days via a suitable ELISA test and 93% protection against the very virulent challenge at the age of 30 days was observed. The maternal immunity interfering with the live IBDV vaccine replication had no detectable effect on the vector vaccine take.