Affine Subspace Representation for Feature Description

This paper proposes a novel Affine Subspace Representation (ASR) descriptor to deal with affine distortions induced by viewpoint changes. Unlike the traditional local descriptors such as SIFT, ASR inherently encodes local information of multi-view patches, making it robust to affine distortions while maintaining a high discriminative ability. To this end, PCA is used to represent affine-warped patches as PCA-patch vectors for its compactness and efficiency. Then according to the subspace assumption, which implies that the PCA-patch vectors of various affine-warped patches of the same keypoint can be represented by a low-dimensional linear subspace, the ASR descriptor is obtained by using a simple subspace-to-point mapping. Such a linear subspace representation could accurately capture the underlying information of a keypoint (local structure) under multiple views without sacrificing its distinctiveness. To accelerate the computation of ASR descriptor, a fast approximate algorithm is proposed by moving the most computational part (ie, warp patch under various affine transformations) to an offline training stage. Experimental results show that ASR is not only better than the state-of-the-art descriptors under various image transformations, but also performs well without a dedicated affine invariant detector when dealing with viewpoint changes.Comment: To Appear in the 2014 European Conference on Computer Visio

Percutaneous transluminal angioplasty in patients with peripheral arterial disease does not affect circulating monocyte subpopulations

Monocytes are mononuclear cells characterized by distinct morphology and expression of CD14 and CD16 surface receptors. Classical, quiescent monocytes are positive for CD14 (lipopolysaccharide receptor) but do not express Fc gamma receptor III (CD16). Intermediate monocytes coexpress CD16 and CD14. Nonclassical monocytes with low expression of CD14 represent mature macrophage-like monocytes. Monocyte behavior in peripheral arterial disease (PAD) and during vessel wall directed treatment is not well defined. This observation study aimed at monitoring of acute changes in monocyte subpopulations during percutaneous transluminal angioplasty (PTA) in PAD patients. Patients with Rutherford 3 and 4 PAD with no signs of inflammatory process underwent PTA of iliac, femoral, or popliteal segments. Flow cytometry for CD14, CD16, HLA-DR, CD11b, CD11c, and CD45RA antigens allowed characterization of monocyte subpopulations in blood sampled before and after PTA (direct angioplasty catheter sampling). Patients were clinically followed up for 12 months. All 61 enrolled patients completed 12-month follow-up. Target vessel failure occurred in 12 patients. While absolute counts of monocyte were significantly lower after PTA, only subtle monocyte activation after PTA (CD45RA and β-integrins) occurred. None of the monocyte parameters correlated with long-term adverse clinical outcome. Changes in absolute monocyte counts and subtle changes towards an activation phenotype after PTA may reflect local cell adhesion phenomenon in patients with Rutherford 3 or 4 peripheral arterial disease

The chiral 1:2 adduct (S)S(S)C(-)589-ethyl 2-phenylbutyl sulphide-mercury (II) chloride:(-)589[(S)S(S)C-Et(2-PhBu)S.(HgCl2)2]. Stereoselective synthesis, asymmetric oxidation, crystal and molecular structure and circular dichroism spectra

Optically active (-)589ethyl (S)-2-phenylbutyl thioether, (-)(S)C-Et(PhBu)S (I), and its new diastereoisomeric mercury (II) chloride adduct, 1:2, (-)[(S)S(S)C-Et(PhBu)S.(HgCl2)2]2, (II) were stereoselectively synthesized; the absorbance (UV) and circular dichroism (CD) spectra were measured and the crystal and molecular structure of complex (II) was determined by single-crystal X-ray diffraction. Two different Hg centres are present whose coordination environments are built by two short bonds to chloride ligands in one case, and to one chloride and one sulphur in the other one. These originate digonal units. Electroneutrality is achieved by a further chlorine, which can be considered prevalently ionic and bonded to the two Hg centres, forming square bridging systems nearly perpendicular to the digonal molecules. The coordination polyhedra can be interpreted as 2 + 4 tetragonally-compressed octahedra with the four longer contacts lying in the equatorial plane. IR spectroscopic data are consistent with the presence of one bent and one linear Cl–Hg–Cl moiety. The absolute configurations at both stereogenic centres of the formed diastereoisomeric complex (II) are (S). The (S)S absolute configuration at the stereogenic sulphur atom bonded to the mercury(II) atom in complex (II) has been related with the negative Cotton effect assigned in its circular dichroism (CD) spectrum to a charge-transfer transition at ca. 230 nm. The stereoselective oxidation of (I) and (II) with hydrogen peroxide, induced by the stereogenic carbon atom (S)C of the enantiopure sulphide, gave (-)598ethyl (S)C-2-phenylbutyl(S)S-sulphoxide, (-)598[(S)S(S)C-Et(PhBu)SO], (III), having 18.1% de. Oxidations carried out in the presence of a 200 molar excess of mercury(II) chloride gave (-)598ethyl (S)C-2-phenylbutyl(R)S-sulphoxide, (-) 598[(R)S(S)C-Et(PhBu)SO], (IV) with 31% de, showing the cooperative influence of mercury(II) chloride on the selectivity of the oxidation reaction

Nox1/4 inhibition exacerbates age dependent perivascular inflammation and fibrosis in a model of spontaneous hypertension

Hypertension is associated with oxidative stress and perivascular inflammation, critical contributors to perivascular fibrosis and accelerated vascular ageing. Oxidative stress can promote vascular inflammation, creating options for potential use of NADPH oxidase inhibitors in pharmacological targeting of perivascular inflammation and its consequences. Accordingly, we characterized age-related changes in oxidative stress and immune cell infiltration in normotensive (WKY) and spontaneously hypertensive rats (SHRs). Subsequently, we used pharmacological inhibitors of Nox1 (ML171) and Nox1/Nox4 (GKT137831; 60 mg/kg), to modulate NADPH oxidase activity at the early stage of spontaneous hypertension and investigated their effects on perivascular inflammation and fibrosis. Results: Ageing was associated with a progressive increase of blood pressure as well as an elevation of the total number of leukocytes, macrophages and NK cells infiltrating perivascular adipose tissue (PVAT) in SHRs but not in WKY. At 1 month of age, when blood pressure was not yet different, only perivascular NK cells were significantly higher in SHR. Spontaneous hypertension was also accompanied by the higher perivascular T cell accumulation, although this increase was age independent. Aortic Nox1 and Nox2 mRNA expression increased with age only in SHR but not in WKY, while age-related increase of Nox4 mRNA in the vessels has been observed in both groups, it was more pronounced in SHRs. At early stage of hypertension (3-months) the most pronounced differences were observed in Nox1 and Nox4. Surprisingly, GKT137831, dual inhibitor of Nox1/4, therapy increased both blood pressure and perivascular macrophage infiltration. Mechanistically, this was linked to increased expression of proinflammatory chemokines expression (CCL2 and CCL5) in PVAT. This inflammatory response translated to increased perivascular fibrosis. This effect was likely Nox4 dependent as the Nox1 inhibitor ML171 did not affect the development of spontaneous hypertension, perivascular macrophage accumulation, chemokine expression nor adventitial collagen deposition. In summary, spontaneous hypertension promotes ageing-associated perivascular inflammation which is exacerbated by Nox4 but not Nox1 pharmacological inhibition

A fast neural-dynamical approach to scale-invariant object detection

We present a biologically-inspired method for object detection which is capable of online and one-shot learning of object appearance. We use a computationally efficient model of V1 keypoints to select object parts with the highest information content and model their surroundings by a simple binary descriptor based on responses of cortical cells. We feed these features into a dynamical neural network which binds compatible features together by employing a Bayesian criterion and a set of previously observed object views. We demonstrate the feasibility of our algorithm for cognitive robotic scenarios by evaluating detection performance on a dataset of common household items. © Springer International Publishing Switzerland 2014

Enhancing real-time human detection based on histograms of oriented gradients

In this paper we propose a human detection framework based on an enhanced version of Histogram of Oriented Gradients (HOG) features. These feature descriptors are computed with the help of a precalculated histogram of square-blocks. This novel method outperforms the integral of oriented histograms allowing the calculation of a single feature four times faster. Using Adaboost for HOG feature selection and Support Vector Machine as weak classifier, we build up a real-time human classifier with an excellent detection rate.Peer Reviewe

Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension.

Recent studies have emphasized the role of perivascular inflammation in cardiovascular disease. We studied mechanisms of perivascular leukocyte infiltration in angiotensin II (Ang II)-induced hypertension and their links to vascular dysfunction. Chronic Ang II infusion in mice increased immune cell content of T cells (255 ± 130 to 1664 ± 349 cells/mg; P \u3c 0.01), M1 and M2 macrophages, and dendritic cells in perivascular adipose tissue. In particular, the content of T lymphocytes bearing CC chemokine receptor (CCR) 1, CCR3, and CCR5 receptors for RANTES chemokine was increased by Ang II (CCR1, 15.6 ± 1.5% vs. 31 ± 5%; P \u3c 0.01). Hypertension was associated with an increase in perivascular adipose tissue expression of the chemokine RANTES (relative quantification, 1.2 ± 0.2 vs. 3.5 ± 1.1; P \u3c 0.05), which induced T-cell chemotaxis and vascular accumulation of T cells expressing the chemokine receptors CCR1, CCR3, and CCR5. Mechanistically, RANTES(-/-) knockout protected against vascular leukocyte, and in particular T lymphocyte infiltration (26 ± 5% in wild type Ang II vs. 15 ± 4% in RANTES(-/-)), which was associated with protection from endothelial dysfunction induced by Ang II. This effect was linked with diminished infiltration of IFN-γ-producing CD8(+) and double-negative CD3(+)CD4(-)CD8(-) T cells in perivascular space and reduced vascular oxidative stress while FoxP3(+) T-regulatory cells were unaltered. IFN-γ ex vivo caused significant endothelial dysfunction, which was reduced by superoxide anion scavenging. In a human cohort, a significant inverse correlation was observed between circulating RANTES levels as a biomarker and vascular function measured as flow-mediated dilatation (R = -0.3, P \u3c 0.01) or endothelial injury marker von Willebrand factor (R = +0.3; P \u3c 0.01). Thus, chemokine RANTES is important in the regulation of vascular dysfunction through modulation of perivascular inflammation.-Mikolajczyk, T. P., Nosalski, R., Szczepaniak, P., Budzyn, K., Osmenda, G., Skiba, D., Sagan, A., Wu, J., Vinh, A., Marvar, P. J., Guzik, B., Podolec, J., Drummond, G., Lob, H. E., Harrison, D. G., Guzik, T. J. Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension

Patch-Based Experiments with Object Classification in Video Surveillance

We present a patch-based algorithm for the purpose of object classification in video surveillance. Within detected regions-of-interest (ROIs) of moving objects in the scene, a feature vector is calculated based on template matching of a large set of image patches. Instead of matching direct image pixels, we use Gabor-filtered versions of the input image at several scales. This approach has been adopted from recent experiments in generic object-recognition tasks. We present results for a new typical video surveillance dataset containing over 9,000 object images. Furthermore, we compare our system performance with another existing smaller surveillance dataset. We have found that with 50 training samples or higher, our detection rate is on the average above 95%. Because of the inherent scalability of the algorithm, an embedded system implementation is well within reach