On Real-Time Synthetic Primate Vision

The primate vision system exhibits numerous capabilities. Some important basic visual competencies include: 1) a consistent representation of visual space across eye movements; 2) egocentric spatial perception; 3) coordinated stereo fixation upon and pursuit of dynamic objects; and 4) attentional gaze deployment. We present a synthetic vision system that incorporates these competencies.We hypothesize that similarities between the underlying synthetic system model and that of the primate vision system elicit accordingly similar gaze behaviors. Psychophysical trials were conducted to record human gaze behavior when free-viewing a reproducible, dynamic, 3D scene. Identical trials were conducted with the synthetic system. A statistical comparison of synthetic and human gaze behavior has shown that the two are remarkably similar

Magnetic domain walls in constrained geometries

Magnetic domain walls have been studied in micrometer-sized Fe20Ni80 elements containing geometrical constrictions by spin-polarized scanning electron microscopy and numerical simulations. By controlling the constriction dimensions, the wall width can be tailored and the wall type modified. In particular, the width of a 180 degree Neel wall can be strongly reduced or increased by the constriction geometry compared with the wall in unconstrained systems.Comment: 4 pages, 6 figure

Hybrid One-Shot 3D Hand Pose Estimation by Exploiting Uncertainties

Model-based approaches to 3D hand tracking have been shown to perform well in a wide range of scenarios. However, they require initialisation and cannot recover easily from tracking failures that occur due to fast hand motions. Data-driven approaches, on the other hand, can quickly deliver a solution, but the results often suffer from lower accuracy or missing anatomical validity compared to those obtained from model-based approaches. In this work we propose a hybrid approach for hand pose estimation from a single depth image. First, a learned regressor is employed to deliver multiple initial hypotheses for the 3D position of each hand joint. Subsequently, the kinematic parameters of a 3D hand model are found by deliberately exploiting the inherent uncertainty of the inferred joint proposals. This way, the method provides anatomically valid and accurate solutions without requiring manual initialisation or suffering from track losses. Quantitative results on several standard datasets demonstrate that the proposed method outperforms state-of-the-art representatives of the model-based, data-driven and hybrid paradigms.Comment: BMVC 2015 (oral); see also http://lrs.icg.tugraz.at/research/hybridhape

Transition state energy decomposition study of acetate-assisted and internal electrophilic substitution C−H bond activation by (acac-O,O)_2Ir(X) complexes (X = CH_3COO, OH)

Chelate-assisted and internal electrophilic substitution type transition states were studied using a DFT-based energy decomposition method. Interaction energies for benzene and methane C−H bond activation by (acac-O,O)_2Ir(X) complexes (X = CH_3COO and OH) were evaluated using the absolutely localized molecular orbital energy decomposition analysis (ALMO-EDA). A ratio of ~1.5:1 for forward to reverse charge-transfer between (acac-O,O)_2Ir(X) and benzene or methane transition state fragments confirms “ambiphilic” bonding, the result of an interplay between the electrophilic iridium center and the internal base component. This analysis also revealed that polarization effects account for a significant amount of transition state stabilization. The energy penalty to deform reactants into their transition state geometry, distortion energy, was also used to understand the large activation energy difference between six-membered and four-membered acetate-assisted transition states and help explain why these complexes do not activate the methane C−H bond

CA 125 in seminal plasma: correlation with semen parameters

Ovarian cancer marker CA 125 was measured in human seminal plasma, and the concentrations ranged between 22 and 1149 U/ml, and between 39 and 4711 U/ejaculate. This very high patient-to-patient variability was in contrast to a much lower within-patient variability, which was comparable to that of other semen parameters. No significant differences in CA 125 concentration were found in seminal plasma from normospermic patients, patients with male factors, vasectomized men, and in aliquots of samples which led to a pregnancy, via artificial insemination or in-vitro fertilization. The seminal plasma CA 125 concentration was not correlated with sperm count, motility and morphology. In contrast, seminal plasma CA 125 concentrations correlated with the age of the patient (P < 0.001) and inversely with the volume of the ejaculate (P < 0.001). These correlations were independent of each other. CA 125 did not correlate with the prostatic marker zinc, but did do so with the seminal vesicle marker fructose and the epididymal marker carnitin

Immunohistochemical localization of pregnancy-associated plasma protein-A in the male genital tract

Pregnancy-associated plasma protein-A (PAPP-A) has been found in seminal fluid at concentrations 10-20 times higher than in plasma. This observation prompted us to undertake a morphological study of the male genital tract with the aid of the immunoperoxidase technique. Immunoreactive cells were found among the Leydig cell population, as well as among the epithelium of the rete testis, the head of the epididymis and the seminal vesicles. The relatively small number of weakly staining epithelial cells leaves open the question of whether PAPP-A is excreted by these cells or whether an active transfer mechanism-possibly in the seminal vesicles-is at work, the Leydig cells increasing the plasma concentration locally, by secretion of PAPP-A into the circulatio

Integrins and adhesion molecules: Gelatinase and oncofetal fibronectin secretion is dependent on integrin expression on human cytotrophoblasts

Collagenolytic activity of cytotrophoblasts is stimulated by glycoproteins of the extracellular matrix and since this stimulation can possibly occur through integrins, we measured the gelatinolytic activity of villous and extravillous cytotrophoblasts according to the type of integrins expressed on these cells. Cytotrophoblasts were isolated from legal abortions, immunopurified with anti-CD45, separated according to their expression of histocompatibility-linked antigen (HLA)-G, α6 or α5 integrin subunits and cultured for 5 days on plastic or agarose. Fetal fibronectin, human chorionic gonadotrophin (HCG) and the gelatinolytic activity were measured in the culture supernatants. Following immunopurification with anti-CD45, the gelatinolytic activity of cytotrophoblasts was significantly higher than before, indicating that contaminating lymphomyeloid cells secreted gelatinolytic inhibitors. HLA-G positive cells secreted significantly more gelatinases than HLA-G negative cells but their HCG secretion was similar. Compared to α5 positive cells, α6 positive cytotrophoblasts secreted significantly more gelatinases, significantly less fibronectin but similar amounts of HCG. We conclude that during trophoblast invasion, extravillous cytotrophoblasts (HLA-G positive) expressing the α6 integrin subunit represent the invasive population of cells (high gelatinase and low fibronectin secretion). When expression of the α5 integrin subunit is turned on, their invasive behaviour ceases and they secrete low amounts of gelatinases and high concentrations of fibronecti

Gelatinase and oncofetal fibronectin secretion is dependent on integrin expression on human cytotrophoblasts

Collagenolytic activity of cytotrophoblasts is stimulated by glycoproteins of the extracellular matrix and since this stimulation can possibly occur through integrins, we measured the gelatinolytic activity of villous and extravillous cytotrophoblasts according to the type of integrins expressed on these cells. Cytotrophoblasts were isolated from legal abortions, immunopurified with anti-CD45, separated according to their expression of histocompatibiltty-linked antigen (HLA)-G, α6 or α5 integrin subunits and cultured for 5 days on plastic or agarose. Fetal fibronectin, human chorionic gonadotrophin (HCG) and the gelatinolytic activity were measured in the culture supernatants. Following immunopurrfication with anti-CD45, the gelatinolytic activity of cytotrophoblasts was significantly higher than before, indicating that contaminating lymphomyeloid cells secreted gelatinolytic inhibitors. HLA-G positive cells secreted significantly more gelatinases than HLA-G negative cells but their HCG secretion was similar. Compared to α5 positive cells, α6 positive cytotrophoblasts secreted significantly more gelatinases, significantly less fibronectin but similar amounts of HCG. We conclude that during trophoblast invasion, extravillous cytotrophoblasts (HLA-G positive) expressing the α6 integrin subunit represent the invasive population of cells (high gelatinase and low fibronectin secretion). When expression of the α5 integrin subunit is turned on, their invasive behaviour ceases and they secrete low amounts of gelatinases and high concentrations of fibronecti

Comparison of a rapid, quantitative and automated assay for urinary luteinizing hormone (LH), with an LH detection test, for the prediction of ovulation

The prediction of ovulation is necessary for oocyte aspiration in a spontaneous cycle and can be reliably achieved only by measuring luteinizing hormone (LH). Since radioimmunoassays of LH take too long for repeated measurements on the same day, we evaluated the possibility of adapting a rapid and fully automated assay of serum LH for use with urine samples. The study group comprised spontaneously ovulating women (38 cycles) who requested artificial insemination. Their serum oestradiol (E2) levels, ultrasound profile (US) and thrice daily urinary LH levels were determined from day 10 of their menstrual cycle. These patients were followed until US signs of follicular rupture were recorded. In all patients, a well-defined LH peak was measured in the urine. This peak lasted 12-15 h and was followed in 35 cycles (no US available for 3) by follicular rupture 9-51 h later. The data were grouped according to the time of the LH peak on day 0. Patients experiencing an LH peak between 0300 h and 0700 h on day 0 had significantly lower levels of E2 on day 0 compared to those with an LH peak between 2200 h and midnight. This is due to the fact that in the patients with an LH peak between 0300 h and 0700 h, E2 levels were already decreasing (from day 1 to day 0), whereas in those with the LH peak between 2200 h and midnight E2 levels were still increasing on the morning of day 0. We conclude that the 30-min IMX LH assay is a reliable, rapid and readily acceptable method for measuring urinary LH and for the prediction of ovulatio