Tagging and Tag Recommendation

Tagging has emerged as one of the best ways of associating metadata with objects (e.g., videos, texts) in Web 2.0 applications. Consisting of freely chosen keywords assigned to objects by users, tags represent a simpler, cheaper, and a more natural way of organizing content than a fixed taxonomy with a controlled vocabulary. Moreover, recent studies have demonstrated that among other textual features such as title, description, and user comments, tags are the most effective to support information retrieval (IR) services such as search, automatic classification, and content recommendation. In this context, tag recommendation services aim at assisting users in the tagging process, allowing users to select some of the recommended tags or to come up with new ones. Besides improving user experience, tag recommendation services potentially improve the quality of the generated tags, benefiting IR services that rely on tags as data sources. Besides the obvious benefit of improving the description of the objects, tag recommendation can be directly applied in IR services such as search and query expansion. In this chapter, we will provide the main concepts related to tagging systems, as well as an overview of tag recommendation techniques, dividing them into two stages of the tag recommendation process: (1) the candidate tag extraction and (2) the candidate tag ranking

Erratum: Martins, M.S., et al. Wideband and wIde beam polyvinylidene difluoride (PVDF) acoustic transducer for broadband underwater. Sensors 2019, 19, 3991

The authors wish to make the following erratum to this paper [...].info:eu-repo/semantics/publishedVersio

Infecção pelo Sugarcane yellow leaf virus causa alterações na eficiência fotossintética e acúmulo de carboidratos nas folhas de cana-de-açúcar

Infection by Sugarcane yellow leaf virus (ScYLV) causes severe leaf symptoms in sugarcane (Saccharum spp.) hybrids, which indicate alterations in its photosynthetic apparatus. To gain an overview of the physiological status of infected plants, we evaluated chlorophyll a fluorescence and gas exchange assays, correlating the results with leaf metabolic surveys, i.e., photosynthetic pigments and carbohydrate contents. When compared to healthy plants, infected plants showed a reduction in potential quantum efficiency for photochemistry of photosystem (PSII) and alterations in the filling up of the plastoquinone (PQ) pool. They also showed reduction in the CO2 net exchange rates, probably as a consequence of impaired quantum yield. In addition, reductions were found in the contents of photosynthetic leaf pigments and in the ratio chlorophyll a/chlorophyll b (chla/chlb). Carbohydrate content in the leaves was increased as a secondary effect of the ScYLV infection. This article discusses the relation of virus replication and host defense responses with general alterations in the photosynthetic apparatus and in the metabolism of infected plants.O vírus do amarelecimento foliar da cana-de-açúcar (Sugarcane yellow leaf virus, ScYLV) causa sintomas foliares severos e típicos de infecção por luteovirus, em cana-de-açúcar (Saccharum spp.). Uma vez que alterações no sistema fotossintético da planta seriam esperadas, avaliaram-se a análise da emissão da fluorescência da clorofila a e as trocas gasosas durante a fotossíntese, relacionando esses dados com análises metabólicas, ou seja, conteúdos de pigmentos fotossintéticos e carboidratos presentes nas folhas. As plantas infetadas apresentaram redução na eficiência quântica fotoquímica potencial do fotossistema II (PSII) e alterações no preenchimento do pool de plastoquinona (PQ). Essas plantas apresentaram, também, redução nas taxas de troca líquida de CO2, provavelmente em conseqüência da redução na eficiência quântica. Paralelamente, reduções nos conteúdos de pigmentos fotossintéticos foliares e na razão clorofila a/clorofila b (chla/chlb) foram verificadas. Adicionalmente, o conteúdo de açúcares nas folhas foi aumentado, provavelmente como um efeito secundário da infecção viral. A relação entre a replicação viral e as respostas de defesa da hospedeira com as alterações encontradas no aparelho fotossintético e no metabolismo das plantas infetadas é discutida.101

Ciliocytophthoria in cervical cytology

The Ciliocytophthoria occurs in the glandular epithelium/cylindrical ciliated cells, which are found in the respiratory and gynaecological systems. Although this phenomenon is considered rare in both systems, it is more unusual in the gynaecological system. Of the 5781 cases analysed at the centre in 2006, only one case was diagnosed as Ciliocytophthoria. In 1975, Kobold-Wolterbeek and Beyer-Boon observed the cervical smears of 18 000 women during a period of a year and a half, during which time a total of 32 cases of Ciliocytophthoria were found. This phenomenon consists of the separation of the cylindrical cells resulting in the formation of a non-nucleus portion – terminal plate with cilia – and a nucleus portion with granular cytoplasm containing eosinophilia inclusions. The relationship between Ciliocytophthoria and any disease or tumour in the female genital tract is unknown.info:eu-repo/semantics/publishedVersio

Underwater energy harvesting to extend operation time of submersible sensors

A linear electromagnetic energy harvesting device for underwater applications, fabricated with a simple manufacturing process, was developed to operate with movement frequencies from 0.1 to 0.4 Hz. The generator has two coils, and the effect of the combination of the two coils was investigated. The experimental study has shown that the energy capture system was able to supply energy to several ocean sensors, producing 7.77 mJ per second with wave movements at 0.4 Hz. This study shows that this energy is enough to restore the energy used by the battery or the capacitor and continue supplying energy to the sensors used in the experimental work. For an ocean wave frequency of 0.4 Hz, the generator can supply power to 8 sensors or 48 sensors, depending on the energy consumed and its optimization.This work is co-funded by the project K2D-Knowledge and Data from the Deep to Space with reference POCI-01-0247-FEDER-045941, co-financed by European Regional Development Fund (ERDF), through the Operational Program for Competitiveness and Internationalization (COMPETE2020) and by the Portuguese Foundation for Science and Technology-FCT under MIT-Portugal Program. This work is also co-financed by Programa Operacional Regional do Norte (NORTE2020), through Fundo Europeu de Desenvolvimento Regional (FEDER), Project NORTE-01-0145-FEDER000032–NextSea, and by national funds through FCT–Fundação para a Ciência e Tecnologia, I.P. under project SONDA (PTDC/EME-SIS/1960/2020)

The challenge of long-distance over-the-air wireless links in the ocean: a survey on water-to-water and water-to-land miot communication

Robust wireless communication networks are a cornerstone of the modern world, allowing data to be transferred quickly and reliably. Establishing such a network at sea, a Maritime Internet of Things (MIoT), would enhance services related to safety and security at sea, environmental protection, and research. However, given the remote and harsh nature of the sea, installing robust wireless communication networks with adequate data rates and low cost is a difficult endeavor. This paper reviews recent MIoT systems developed and deployed by researchers and engineers over the past few years. It contains an analysis of short-range and long-range over-the-air radio-frequency wireless communication protocols and the synergy between these two in the pursuit of an MIoT. The goal of this paper is to serve as a go-to guide for engineers and researchers that need to implement a wireless sensor network at sea. The selection criterion for the papers included in this review was that the implemented wireless communication networks were tested in a real-world scenario.cofunded by the project K2D: Knowledge and Data from the Deep to Space with reference POCI-01-0247-FEDER-045941, cofinanced by the European Regional Development Fund (ERDF), through the Operational Program for Competitiveness and Internationalization (COMPETE2020), and by the Portuguese Foundation for Science and Technology (FCT) under the MIT Portugal Program. This work is also cofinanced by national funds through FCT–Fundação para a Ciência e Tecnologia, I.P., under project SONDA (PTDC/EME-SIS/1960/2020). T.M. thanks FCT for grant SFRH/BD/145070/201