165 research outputs found
A context based model for sentiment analysis in twitter for the italian language
Studi recenti per la Sentiment
Analysis in Twitter hanno tentato di creare
modelli per caratterizzare la polarit´a di
un tweet osservando ciascun messaggio
in isolamento. In realt`a, i tweet fanno
parte di conversazioni, la cui natura pu`o
essere sfruttata per migliorare la qualit`a
dell’analisi da parte di sistemi automatici.
In (Vanzo et al., 2014) `e stato proposto un
modello basato sulla classificazione di sequenze
per la caratterizzazione della polarit`
a dei tweet, che sfrutta il contesto in
cui il messaggio `e immerso. In questo lavoro,
si vuole verificare l’applicabilit`a di
tale metodologia anche per la lingua Italiana.Recent works on Sentiment
Analysis over Twitter leverage the idea
that the sentiment depends on a single
incoming tweet. However, tweets are
plunged into streams of posts, thus making
available a wider context. The contribution
of this information has been recently
investigated for the English language by
modeling the polarity detection as a sequential
classification task over streams of
tweets (Vanzo et al., 2014). Here, we want
to verify the applicability of this method
even for a morphological richer language,
i.e. Italian
Modeling of an Air Conditioning System with Geothermal Heat Pump for a Residential Building
The need to address climate change caused by greenhouse gas emissions attaches great importance to research aimed at using renewable energy. Geothermal energy is an interesting alternative concerning the production of energy for air conditioning of buildings (heating and cooling), through the use of geothermal heat pumps. In this work a model has been developed in order to simulate an air conditioning system with geothermal heat pump. A ground source heat pump (GSHP) uses the shallow ground as a source of heat, thus taking advantage of its seasonally moderate temperatures. GSHP must be coupled with geothermal exchangers. The model leads to design optimization of geothermal heat exchangers and to verify the operation of the geothermal plant
Solitary Internal Mammary Lymph Node Metastases Detected by 18F-FDG-PET/CT in Ovarian Cancer
Internal mammary lymph nodes as solitary site of recurrent ovarian cancer have not been previously described. In this case report, 3 cases of late and very late isolated recurrence in internal mammary lymph nodes are presented. 18F-FDG-PET/CT allowed the diagnosis which was suspected by the increase of the serum CA-125 level in 2 out of 3 cases. Local treatment, consisting of surgery (in 2 patients) and radiation therapy (in 1 patient), permitted an optimal long-term disease control
Editorial: Acute Unilateral Vestibulopathy: clinical presentation, instrumental patterns, evolution and management
Spontaneous Upbeat Nystagmus and Selective Anterior Semicircular Canal Hypofunction on Video Head Impulse Test: A New Variant of Canalith Jam?
: We describe a rare case of spontaneous upbeat nystagmus (UBN) attributable to a canalith jam involving the anterior semicircular canal (ASC) in a patient in whom comprehensive vestibular assessment was useful to identify the underlying pathomechanism. A 56-year-old woman with unsteadiness following repositioning procedures for left-sided benign paroxysmal positional vertigo (BPPV) presented with spontaneous UBN that showed slight right torsional components. A vestibular test battery detected isolated left ASC hypofunction on a video-head impulse test (Video-HIT). We postulated a persistent utriculopetal deflection of the left ASC cupula, which was attributable to entrapment of debris in a narrow canal tract, with consequent sustained inhibition of the ampullary afferents. Although spontaneous UBN receded after impulsive physical therapy, unsteadiness deteriorated into positional vertigo secondary to canalolithiasis involving the ipsilateral posterior canal. In our view, physical therapy possibly fragmented the canalith jam and released free-floating otoconia that eventually settled into the ipsilateral posterior canal. Video HIT revealed normalization of ASC hypofunction, and leftsided posterior canal canalolithiasis was successfully treated using appropriate repositioning procedures. We propose that a canalith jam involving the ASC should be considered in the differential diagnosis of spontaneous UBN, particularly in patients with a history of BPPV and isolated ASC hypofunction detected on video HIT
Context-aware Models for Twitter Sentiment Analysis
Recent works on Sentiment Analysis over Twitter are tied to the idea that the sentiment can be completely captured after reading an incoming tweet. However, tweets are filtered through streams of posts, so that a wider context, e.g. a topic, is always available. In this work, the contribution of this contextual information is investigated for the detection of the polarity of tweet messages. We modeled the polarity detection problem as a sequential classification task over streams of tweets. A Markovian formulation of the Support Vector Machine discriminative model has been here adopted to assign the sentiment polarity to entire sequences. The experimental evaluation proves that sequential tagging better embodies evidence about the contexts and is able to increase the accuracy of the resulting polarity detection process. These evidences are strengthened as experiments are successfully carried out over two different languages: Italian and English. Results are particularly interesting as the approach is flexible and does not rely on any manually coded resources
Neural sentiment analysis for a real-world application
In this paper, we describe our neural network models for a commercial application on sentiment analysis. Different from academic work, which is oriented towards complex networks for achieving a marginal improvement, real scenarios require flexible and efficient neural models. The possibility to use the same models on different domains and languages plays an important role in the selection of the most appropriate architecture. We found that a small modification of the state-of-the-art network according to academic benchmarks led to a flexible neural model that also preserves high accuracy. In questo lavoro, descriviamo i nostri modelli di reti neurali per un'applicazione commerciale basata sul sentiment analysis. A differenza del mondo accademico, dove la ricerca è orientata verso reti anche complesse per il raggiungimento di un miglioramento marginale, gli scenari di utilizzo reali richiedono modelli neurali flessibili, efficienti e semplici. La possibilitá di utilizzare gli stessi modelli per domini e linguaggi variegati svolge un ruolo importante nella scelta dell'architettura. Abbiamo scoperto che una piccola modifica della rete allo stato dell'arte rispetto ai benchmarks accademici produce un modello neurale flessibile che preserva anche un'elevata precisione
Placental Expression of CD100, CD72 and CD45 Is Dysregulated in Human Miscarriage
CONTEXT AND OBJECTIVE: The etiology of miscarriage is often multifactorial. One major cause, immunological rejection of the fetus, has not been clearly elucidated. Our aim was to establish whether the semaphorin CD100, its natural receptor CD72, and the glycoprotein CD45, implicated in immune mechanisms, are involved in pregnancy loss by examining their placental expression with real-time PCR, immunohistochemistry and western blotting techniques. PATIENTS: Placenta tissue from 72 Caucasian women undergoing surgical uterine evacuation due to early spontaneous pregnancy loss between the 8(th) and 12(th) week of gestation was divided into four groups based on miscarriage number. Gestational age-matched placentas from 18 healthy women without a history of miscarriage undergoing voluntary pregnancy termination were the control group. Placenta from 6 Caesarean deliveries performed at 38-40 weeks of gestation was also studied. RESULTS: CD100, CD72 and CD45 were expressed in placenta and exhibited different mRNA and protein levels in normal pregnancy and miscarriage. In particular, protein levels were highly dysregulated around 10 weeks of gestation in first and second miscarriage placentas. The CD100 soluble form was produced and immediately shed from placental tissue in all samples. CONCLUSIONS: Fetal CD100, CD72 and CD45 seem to play a role in miscarriage. The present data support the involvement of the fetal immune system in pregnancy maintenance as well as failure
CXCR1 and SLC11A1 polymorphisms affect susceptibility to cutaneous leishmaniasis in Brazil: a case-control and family-based study.
BACKGROUND: L. braziliensis causes cutaneous (CL) and mucosal (ML) leishmaniasis. Wound healing neutrophil (PMN) and macrophage responses made following the bite of the vector sand fly contribute to disease progression in mice. To look at the interplay between PMN and macrophages in disease progression in humans we asked whether polymorphisms at genes that regulate their infiltration or function are associated with different clinical phenotypes. Specifically, CXCR1 (IL8RA) and CXCR2 (IL8RB) are receptors for chemokines that attract PMN to inflammatory sites. They lie 30-260 kb upstream of SLC11A1, a gene known primarily for its role in regulating macrophage activation, resistance to leishmaniasis, and wound healing responses in mice, but also known to be expressed in PMN, macrophages and dendritic cells. METHODS: Polymorphic variants at CXCR1, CXCR2 and SLC11A1 were analysed using Taqman or ABI fragment separation technologies in cases (60 CL; 60 ML), unrelated controls (n = 120), and multicase families (104 nuclear families; 88 ML, 250 CL cases) from Brazil. Logistic regression analysis, family-based association testing (FBAT) and haplotype analysis (TRANSMIT) were performed. RESULTS: Case-control analysis showed association between the common C allele (OR 2.38; 95% CI 1.23-4.57; P = 0.009) of CXCR1_rs2854386 and CL, supported by family-based (FBAT; Z score 2.002; P = 0.045) analysis (104 nuclear families; 88 ML, 250 CL cases). ML associated with the rarer G allele (Z score 1.999; P = 0.046). CL associated with a 3' insertion/deletion polymorphism at SLC11A1 (Z score 2.549; P = 0.011). CONCLUSIONS: The study supports roles for CXCR1 and SLC11A1 in the outcome of L. braziliensis infection in humans. Slc11a1 does not influence cutaneous lesion development following needle injection of Leishmania in mice, suggesting that its role here might relate to the action of PMN, macrophage and/or dendritic cells in the wound healing response to the sand fly bite. Together with the CXCR1 association, the data are consistent with hypotheses relating to the possible role of PMN in initiation of a lesion following the delivery of parasites via the sand fly bite. Association of ML with the rare derived G allele suggests that PMN also have an important positive role to play in preventing this form of the disease.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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