Holistic context models for visual recognition

A novel framework to context modeling based on the probability of co-occurrence of objects and scenes is proposed. The modeling is quite simple, and builds upon the availability of robust appearance classifiers. Images are represented by their posterior probabilities with respect to a set of contextual models, built upon the bag-of-features image representation, through two layers of probabilistic modeling. The first layer represents the image in a semantic space, where each dimension encodes an appearance-based posterior probability with respect to a concept. Due to the inherent ambiguity of classifying image patches, this representation suffers from a certain amount of contextual noise. The second layer enables robust inference in the presence of this noise by modeling the distribution of each concept in the semantic space. A thorough and systematic experimental evaluation of the proposed context modeling is presented. It is shown that it captures the contextual “gist” of natural images. Scene classification experiments show that contextual classifiers outperform their appearance-based counterparts, irrespective of the precise choice and accuracy of the latter. The effectiveness of the proposed approach to context modeling is further demonstrated through a comparison to existing approaches on scene classification and image retrieval, on benchmark data sets. In all cases, the proposed approach achieves superior results.     

Quantitative analysis of pore patterns on rat prostate nuclei using spatial statistics methods

Spatial statistics methods have been used to analyse the nuclear pore pattern in rat ventral prostate nuclei isolated from adult animals. The observed results show that: (1) pores on prostate nuclear membranes are not randomly distributed; (2) the data sets obtained from different micrographs are consistent with the same statistical model thus suggesting the existence of a typical pore distribution.     

Morphological characterization of the nymphs Rhipicephalus sanguineus ticks (Latreille, 1806) (Acari: Ixodidae). Description of the testes, integument, Malpighian tubules, and midgut on the detachment day

This study presents the morpho-histological and histochemical characterization of the testes, integument, Malpighian tubules, and midgut of engorged Rhipicephalus sanguineus nymphs on the detachment day, showing the morphological and physiological characteristics to this phase in the life cycle of these individuals. The testis is constituted by germinative cells (only spermatogonia) with large, round-shaped and strongly stained nuclei which are organized into cysts by a thin layer of somatic cells. The integument consists of a cuticle subdivided into epicuticle (lipoprotein) and procuticle (glycoproteic), and a layer of epithelial cells which present glycolipoprotein elements. The procuticle presents two distinct regions: the exocuticle (next to the epicuticle) and the endocuticle (next to the epithelial layer). The Malpighian tubules present a simple epithelium with small flat and/or cubic cells, which form its wall and delimitates a lumen full of lipoprotein material. The midgut consists of an epithelial wall formed by two types of digestive cells, spent cells and empty digest cells, and by generative cells supported by a basal lamina and a thin layer of muscular tissue. This study described the main organs of engorged nymphs of R. sanguineus, to generate information that can help researchers to better understand the biology of these ectoparasites; which is fundamental for the development of compounds that are less aggressive to the environment. In addition, if the immature stages of the ticks are controlled, the number of adult ticks able to cause damages to the animals--and to the man as well--is also under control.     

Strawberries from integrated pest management and organic farming: Phenolic composition and antioxidant properties

Consumer awareness, pesticide and fertilizer contaminations and environmental concerns have resulted in significant demand for organically grown farm produce. Consumption of berries has become popular among health-conscious consumers due to the high levels of valuable antioxidants, such as anthocyanins and other phenolic compounds. The present study evaluated the influence that organic farming (OF) and integrated pest management (IPM) practise exert on the total phenolic content in 22 strawberry samples from four varieties. Postharvest performance of OF and IPM strawberries grown in the same area in the centre of Portugal and harvested at the same maturity stage were compared. Chemical profiles (phenolic compounds) were determined with the aid of HPLC-DAD/MS. Total phenolic content was higher for OF strawberry extracts. This study showed that the main differences in bioactive phytochemicals between organically and IPM grown strawberries concerned their anthocyanin levels. Organically grown strawberries were significantly higher in antioxidant activity than were the IPM strawberries, as measured by DPPH and FRAP assays.     

Time and space for segmenting personal photo sets

Multimedia Tools and Applications - A personal collection of photos shows large variability in the depicted items, making difficult a fully automated solution to cope with sensory and semantic...     

A Low-Power Wakeup Radio for Application in WSN-Based Indoor Location Systems

This paper presents a low-power wakeup radio (WUR) for application in indoor location systems. The presented radio has a better performance than the state-of-the-art radios, since it has low-power consumption, only 10 μW and it is perfectly integrated into a wireless sensor network based on ZigBee, which is used for location purposes. This performance was achieved due to an optimised radio frequency design of the WUR, which was embedded with a low-cost/low-power processor, and due to an enhanced control algorithm. Moreover, a software defined radio approach has been used to implement the WUR protocol. The WUR was designed and integrated in an existing WSN-based indoor location system which was originally based on a periodic sleep-wake up duty-cycled protocol. In the WUR protocol the location sensor is kept in deep sleep mode until it receives an external wake-up order. According to estimates, with this scheme, the battery lifetime can be increased from 200 days (using conventional duty-cycle protocol) up to almost 8000 days (sensor waken-up few times per day).     

Scalable Data Processing for Community Sensing Applications

Participatory Sensing is a new computing paradigm that aims to turn personal mobile devices into advanced mobile sensing networks. For popular applications, we can expect a huge number of users to both contribute with sensor data and request information from the system. In such scenario, scalability of data processing becomes a major issue. In this paper, we present a system for supporting participatory sensing applications that leverages cluster or cloud infrastructures to provide a scalable data processing infrastructure. We propose and evaluate three strategies for data processing in this architecture.