Segmentation Propagation in ImageNet

Abstract. ImageNet is a large-scale hierarchical database of object classes. We propose to automatically populate it with pixelwise segmentations, by leveraging existing manual annotations in the form of class labels and bounding-boxes. The key idea is to recursively exploit images segmented so far to guide the segmentation of new images. At each stage this propagation process expands into the images which are easiest to segment at that point in time, e.g. by moving to the semantically most related classes to those segmented so far. The propagation of segmentation occurs both (a) at the image level, by transferring existing segmentations to estimate the probability of a pixel to be foreground, and (b) at the class level, by jointly segmenting images of the same class and by importing the appearance models of classes that are already segmented. Through an experiment on 577 classes and 500k images we show that our technique (i) annotates a wide range of classes with accurate segmentations; (ii) effectively exploits the hierarchical structure of ImageNet; (iii) scales efficiently; (iv) outperforms a baseline GrabCut [1] initialized on the image center, as well as our recent segmentation transfer technique [2] on which this paper is based. Moreover, our method also delivers state-of-the-art results on the recent iCoseg dataset for co-segmentation.

Depressive Symptoms in Danish Elite Athletes Using the Major Depressive Inventory (MDI) and the Center for Epidemiological Studies Depression Scale (CES-D)

Background: The prevalence of depressive symptoms among athletes is an ongoing debate in the scientific literature. Aims: The aim of the current study was to assess the prevalence of depressive symptoms in Danish elite athletes and to evaluate the psychometric properties of the Major Depressive Inventory (MDI) and the Center for Epidemiological Studies Depression Scale (CES-D) in athletes. Methods: The total sample comprised 996 athletes from two cross-sectional studies using the MDI (n = 409) and the CES-D (n = 587). Results: Using the original cut-off points, the MDI found 8.6% and the CES-D found 22.0% at risk of depression. Using alternative cut-off points recommended in the literature, both instruments detected 10-11% of athletes at risk of depression. No statistically significant differences were found related to age, injury, and type of sport between high risk and low risk groups, whereas female gender was identified as a risk factor for higher depressive symptoms. Principal component analyses confirmed a single factor structure in both instruments with sufficient item loadings on the first component and Cronbach α values of .89 and .88. Discussion: We recommend regular screening of depressive symptoms in elite athletes, with MDI and CES-D as reliable instrument for that purpose

Autonomous Guidance Around Small Bodies Using Continuous-Thrust Propulsion

In recent years, there have been a number of successful missions flown to small bodies. While these missions had very different spacecraft designs, mission profiles, and scientific objectives; they all used an open-loop spacecraft guidance approach for mission operations. Open-loop guidance approaches are becoming less feasible due to communication constraints, mission complexity, and rising mission costs. Furthermore, spacecraft that operate around small bodies are able to use highly efficient electric propulsion systems for mission operations due to the small gravitational wells associated with small bodies. However, current small-body guidance techniques are unable to execute the finite, continuous maneuvers associated with electric propulsion systems due to their open-loop guidance architecture. As such, there is a gap in current autonomous spacecraft guidance techniques that inhibits the ubiquitous use of electric propulsion around small bodies. This dissertation presents a new method for autonomous spacecraft guidance that is capable of performing continuous-thrust maneuvers around small bodies. This is accomplished by developing an autonomous continuous-thrust guidance (ACTG) algorithm that is able to design mission profiles in the small body dynamic environment and then execute those mission profiles in the face of state and dynamic uncertainty onboard a spacecraft. This is achieved using computationally efficient maneuver targeting and guidance techniques inspired by continuous-thrust, finite-burn guidance algorithms around Earth and adapting them to meet the needs of the small body dynamic environment. The ACTG algorithm plans and executes continuous-thrust spacecraft missions in the small body environment using a parametric, optimal, constant-thrust bilinear tangent guidance law, a Lambert solver coupled with an iterative quasi-Newton minimization algorithm, a Newton-Raphson predictor-corrector guidance algorithm, and additional autonomous explicit guidance techniques.</p

Real-Time Face Pose Estimation from Single Range Images

We present a real-time algorithm to estimate the 3D pose of a previously unseen face from a single range image. Based on a novel shape signature to identify noses in range images, we generate candidates for their positions, and then generate and evaluate many pose hypotheses in parallel using modern graphics processing units (GPUs). We developed a novel error function that compares the input range image to precomputed pose images of an average face model. The algorithm is robust to large pose variations of plusmn90deg yaw, plusmn45deg pitch and plusmn30deg roll rotation, facial expression, partial occlusion, and works for multiple faces in the field of view. It correctly estimates 97.8% of the poses within yaw and pitch error of 15deg at 55.8 fps. To evaluate the algorithm, we built a database of range images with large pose variations and developed a method for automatic ground truth annotation.Engineering and Applied Science

Cytoskeletal Changes During Radiation-Induced Neoplastic Transformation of Human Prostate Epithelial Cells

We recently reported tumorigenic transformation of SV 40-immortalized neonatal human prostate epithelial cells (267Bl) by exposure to fractionated doses of X-rays. Altered morphology and anchorage independence were observed following two successive fractions of 2 Gy each (F3-SAC). Additional 2 Gy treatments to these non-tumorigenic cells to a total dose of 30 Gy resulted in radiation-transformed tumorigenic colonies (267Bl-SXR). Malignant transformation of parental 267B 1 cells was also achieved by consecutive 2 Gy exposures to a total dose of 30 Gy (267Bl-XR). This study discusses the cytoskeletal changes in the F3-SAC, 267Bl-XR and 267Bl-SXR derivatives of these human prostate epithelial cells. Confocal and conventional fluorescence microscopy of filamentous actin showed numerous, well organized, evenly distributed stress fibers in the parental cells prior to irradiation, while the anchorage-independent cells and several tumorigenic derivatives exhibited poor stress fiber organization after radiation exposure. This disorganization of actin microfilaments in the radiation-transformed cells was also accompanied by changes in the expression of selective tropomyosin isoforms as judged by two-dimensional gel electrophoresis. These changes in actin organization and tropomyosin expression appear to be coincidental with morphological transformation and acquisition of tumorigenicity in the 267Bl cells following radiation exposure

Retirement from elite sport and self-esteem: a longitudinal study over 12 years

This study examined the complex associations between athletic retirement and self-esteem among former elite athletes. With reference to theoretical and empirical work on the quality of the transition out of sport, information was collected from 290 (junior) elite athletes in a retrospective-prospective design: at the first measurement, active athletes assessed satisfaction with their sporting career, athletic identity, and self-esteem. At the second measurement (12  years later), the now former athletes rated transition characteristics of their career ending, sporting career success, emotional reactions to career termination, extent of necessary adjustment required following athletic retirement, duration and quality of adjustment, and self-esteem. Structural equation modelling revealed that neither sporting career success nor sporting career satisfaction had a direct effect on adjustment. However, athletic identity and retirement planning predicted the extent of adjustment, which in turn predicted the duration and quality of adjustment, and ultimately self-esteem. Voluntariness, timeliness, and perceptions of gain predicted emotional reactions towards career termination, which also predicted the duration of adjustment. Extent of adjustment and emotional reactions mediated between preconditions of career termination and transition characteristics and self-esteem. While self-esteem after career termination was predominantly predicted by self-esteem 12  years earlier, perceived quality of adjustment to career termination had a significant effect on self-esteem in the post-athletic career. These results complement existing literature illustrating that athletic retirement is a complex and dynamic process and the quality of this transition has a small, but still noteworthy effect on self-esteem, a central construct for well-being

In-hospital Delay Increases the Risk of Perforation in Adults with Appendicitis

Background: The influence of in-hospital delay (time between admission and operation) on outcome after appendectomy is controversial. Methods: A total of 1,827 adult patients underwent open or laparoscopic appendectomy for suspected appendicitis in eleven Swiss hospitals between 2003 and 2006. Of these, 1,675 patients with confirmed appendicitis were included in the study. Groups were defined according in-hospital delay (≤12 vs. >12h). Results: Delay>12h was associated with a significantly higher frequency of perforated appendicitis (29.7 vs. 22.7%; P=0.010) whereas a delay of 6 or 9h was not. Size of institution, time of admission, and surgical technique (laparoscopic vs. open) were independent factors influencing in-hospital delay. Admission during regular hours was associated with higher age, higher frequency of co-morbidity, and higher perforation rate compared to admission after hours. The logistic regression identified four independent factors associated with an increased perforation rate: age (≤65years vs. >65years, odds ratio (OR) 4.5, P0 vs. Charlson index=0, OR 2.3, P12 vs. ≤12h, OR 1.5, P=0.005). Perforation was associated with an increased reintervention rate (13.4 vs. 1.6%; P<0.001) and longer length of hospital stay (9.5 vs. 4.4days; P<0.001). Conclusions: In-hospital delay negatively influences outcome after appendectomy. In-hospital delay of more than 12h, age over 65years, time of admission during regular hours, and the presence of co-morbidity are all independent risk factors for perforation. Perforation was associated with a higher reintervention rate and increased length of hospital sta

Radiation-Induced Neoplastic Transformation of Human Cells

Ionizing radiation can induce cancers in humans and animals and can cause in vitro neoplastic transformation of various rodent cell systems. However, numerous attempts to achieve neoplastic transformation of human cells by radiation have generally proven unsuccessful. Neoplastic transformation of immortalized human epidermal keratinocytes by X-ray irradiation has recently been reported. The carcinogenic effect of radiation on cultured human cells will be briefly reviewed. The current state-of-the-art in radiation-induced transformation of human cells in culture is presented. This will provide insight into the molecular and cellular mechanisms in the conversion of normal cells to a neoplastic state of growth