5,868 research outputs found

    Progame:event-based machine learning approach for in-game marketing

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    Abstract. There’s been a significant growth in the gaming industry, which has lead to an increased number of collected player and usage data, including game events, player interactions, the connections between players and individual preferences. Such big data has many use cases such as the identification of gaming bottlenecks, detection and prediction of anomalies and suspicious usage patterns for security, and real time offer specification via fine-grained user profiling based on their interest profiles. Offering personalized offer timing could reduce product cannibalization, and ethical methods increase the trust of customers. The goal of this thesis is to predict the value and time of the next in-game purchase in a mobile game. Using data aggregation, event-based purchase data, daily in-game behaviour metrics and session data are combined into a single data table, from which samples of 50 000 data points are taken. The features are analyzed for linear correlation with the labels, and their combinations are used as input for three machine learning algorithms: Random Forest, Support Vector Machine and Multi-Layer Perceptron. Both purchase value and purchase time are correlated with features related to previous purchase behaviour. Multi-Layer Perceptron showed the lowest error in predicting both labels, showing an improvement of 22,0% for value in USD and 20,7% for days until purchase compared to a trivial baseline predictor. For ethical customer behaviour prediction, sharing of research knowledge and customer involvement in the data analysis process is suggested to build awareness.Progame : tapahtumapohjainen koneoppimisjärjestelmä pelinsisäiseen markkinointiin. Tiivistelmä. Peliteollisuuden kasvu on johtanut kerättävän pelaaja- ja käyttödatan määrään nousuun, koostuen mm. pelitapahtumista, interaktiodatasta, pelaajien välisistä yhteyksistä ja henkilökohtaisista mieltymyksistä. Tällaisella massadatalla on monia käyttötarkoituksia kuten tietoliikenteen teknisten rajoitusten tunnistaminen pelikäytössä, käyttäjien tavallisuudesta poikkeavan käytöksen tunnistaminen ja ennustaminen tietoturvatarkoituksiin, sekä reaaliaikainen tarjousten määrittäminen hienovaraisella käyttäjien mieltymysten profiloinnilla. Ostotarjousten henkilökohtaistaminen voi vähentää uusien tuotteiden aiheuttamaa vanhojen tuotteiden myynnin laskua, ja eettiset menetelmät parantavat asiakkaiden luottamusta. Tässä työssä ennustetaan asiakkaan seuraavan pelinsisäisen oston arvoa ja aikaa mobiilipelissä. Tapahtumapohjainen ostodata, päivittäiset pelin sisäiset metriikat ja sessiodata yhdistetään yhdeksi datataulukoksi, josta otetaan kerrallaan 50 000:n datarivin näytteitä. Jokaisen selittävän muuttujan lineaarinen korrelaatio ennustettavan muuttujan kanssa analysoidaan, ja niiden yhdistelmiä käytetään syötteenä kolmelle eri koneoppimismallille: satunnainen metsä (Random Forest), tukivektorikone (Support Vector Machine) ja monikerroksinen perseptroniverkko (Multi-Layer Perceptron). Tutkimuksessa havaittiin, että sekä tulevan oston arvo että ajankohta korreloivat aiemman ostokäyttäytymisen kanssa. Monikerroksisella perseptroniverkolla oli pienin virhe molemmille ennustettaville muuttujille, ja verrattuna triviaaliin vertailuennustimeen, se vähensi virhettä 22,0% arvon ennustamisessa ja 20,7% seuraavaan ostoon jäljellä olevien päivien ennustamisessa. Eettisen asiakkaiden käyttäytymisen ennustamisen varmistamiseksi ja tietoisuuden lisäämiseksi ehdotetaan tutkimustiedon jakamista ja asiakkaan ottamista mukaan analyysin tekemiseen

    Bilateral gluteal metastases from a misdiagnosed intrapelvic gastrointestinal stromal tumor

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    <p>Abstract</p> <p>Background</p> <p>The location of gastrointestinal stromal tumors (GIST) outside of the gastrointestinal system is a rare event.</p> <p>Case presentation</p> <p>A 56-year old woman presented with a GIST of the pelvis was misdiagnosed and treated as a uterine leiomyosarcoma. The diagnosis was made after the CD117 (KIT) positivity in the biopsy of the excised bowel mass four years from the first presentation. During this period she presented a bilateral muscle and subcutaneous metastasis in the gluteal area.</p> <p>Conclusion</p> <p>The correct diagnosis of the extra-gastrointestinal stromal tumor is a challenge even for experienced pathologists. CD117 (KIT) positivity is the most important immunohistochemical feature in the histological diagnosis. To our knowledge a metastatic EGIST (extra-gastrointestinal stromal tumor) to the skeletal muscle bilaterally has not been described previously in the English medical literature.</p

    Identification of transcriptional and metabolic programs related to mammalian cell size

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    SummaryBackgroundRegulation of cell size requires coordination of growth and proliferation. Conditional loss of cyclin-dependent kinase 1 in mice permits hepatocyte growth without cell division, allowing us to study cell size in vivo using transcriptomics and metabolomics.ResultsLarger cells displayed increased expression of cytoskeletal genes but unexpectedly repressed expression of many genes involved in mitochondrial functions. This effect appears to be cell autonomous because cultured Drosophila cells induced to increase cell size displayed a similar gene-expression pattern. Larger hepatocytes also displayed a reduction in the expression of lipogenic transcription factors, especially sterol-regulatory element binding proteins. Inhibition of mitochondrial functions and lipid biosynthesis, which is dependent on mitochondrial metabolism, increased the cell size with reciprocal effects on cell proliferation in several cell lines.ConclusionsWe uncover that large cell-size increase is accompanied by downregulation of mitochondrial gene expression, similar to that observed in diabetic individuals. Mitochondrial metabolism and lipid synthesis are used to couple cell size and cell proliferation. This regulatory mechanism may provide a possible mechanism for sensing metazoan cell size

    On the number of signals in multivariate time series

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    We assume a second-order source separation model where the observed multivariate time series is a linear mixture of latent, temporally uncorrelated time series with some components pure white noise. To avoid the modelling of noise, we extract the non-noise latent components using some standard method, allowing the modelling of the extracted univariate time series individually. An important question is the determination of which of the latent components are of interest in modelling and which can be considered as noise. Bootstrap-based methods have recently been used in determining the latent dimension in various methods of unsupervised and supervised dimension reduction and we propose a set of similar estimation strategies for second-order stationary time series. Simulation studies and a sound wave example are used to show the method's effectiveness

    Carbon dynamics in a Boreal land-stream-lake continuum during the spring freshet of two hydrologically contrasting years

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    We studied in 2013 and 2014 the spring carbon dynamics in a Boreal landscape consisting of a lake and 15 inflowing streams and an outlet. The first year had weather and a hydrological regime typical of past years with a distinct spring freshet connected with the thaw of the average snowpack. The latter year had higher air temperatures which did not permit snow accumulation, despite similar winter precipitation. As such, there was hardly any spring freshet in 2014, and stream discharge peaked in January, i.e., the conditions resembled those predicted in the future climate. Despite the hydrological differences between the years, there were only small interannual differences in the stream CO2 and DOC concentrations. The relationship between the concentrations and discharge was stronger in the typical year. CO2 concentrations in medium-sized streams correlated negatively with the discharge, indicating dilution effect of melting snowpacks, while in large-sized streams the correlation was positive, suggesting stronger groundwater influence. The DOC pathway to these streams was through the subsurface soil layers, not the groundwater. The total amount of carbon transported into the lake was ca. 1.5-fold higher in the typical year than in the year with warm winter. In 2013, most of the lateral inputs took place during spring freshet. In 2014, the majority of inputs occurred earlier, during the winter months. The lateral CO2 signal was visible in the lake at 1.5 m depth. DOC dominated the carbon transport, and in both years, 12% of the input C was in inorganic form.Peer reviewe

    Role of the carboxyl terminal di-leucine in phosphorylation and internalization of C5a receptor

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    AbstractThe carboxyl tail of G protein-coupled receptors contains motifs that regulate receptor interactions with intracellular partners. Activation of the human neutrophil complement fragment C5a receptor (C5aR) is terminated by phosphorylation of the carboxyl tail followed by receptor internalization. In this study, we demonstrated that bulky hydrophobic residues in the membrane-proximal region of the C5aR carboxyl tail play an important role in proper structure and function of the receptor: Substitution of leucine 319 with alanine (L319A) resulted in receptor retention in the endoplasmic reticulum, whereas a L318A substitution allowed receptor transport to the cell surface, but showed slow internalization upon activation, presumably due to a defect in phosphorylation by both PKC and GRK. Normal agonist-induced activation of ERK1/2 and intracellular calcium release suggested that the L318A mutation did not affect receptor signaling. Binding of GRK2 and PKCβII to intracellular loop 3 of C5aR in vitro indicated that mutagenesis of L318 did not affect kinase binding. Limited proteolysis with trypsin revealed a conformational difference between wild type and mutant receptor. Our studies support a model in which the L318/L319 stabilizes an amphipathic helix (Q305–R320) in the membrane-proximal region of C5aR

    Six years survival on imatinib with no disease progression after diagnosis of metastatic duodenal gastrointestinal stromal tumour: a case report

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    Introduction: A duodenal Gastrointestinal Stromal Tumour (GIST) is a rare finding and until recently advanced disease had a poor prognosis. A PubMed search revealed no reports of more than five years survival of inoperable GIST on chemotherapy with WHO performance status zero. Case Presentation: A 68 year old female was diagnosed with unresectable GIST in the duodenum with metastasis to liver, pancreas and omentum in November 2001. She was commenced on imatinib mesylate (Glivec) chemotherapy. This case report was prepared from the medical records and radiology reports. She had good tolerance with stable disease. After six years her CT scan showed no disease progression and her WHO performance status was zero. Conclusion: This report supports the view that imatinib is a safe and effective drug in controlling disease progression in advanced metastatic GIST and plays an important role in improving the patient's quality of life

    AIDS-Related EBV-Associated Smooth Muscle Tumors: A Review of 64 Published Cases

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    The number of reported cases of smooth muscle tumor (SMT) arising in patients with AIDS has been increasing since the mid-1990s. The aim of this study is to characterize the epidemiology, clinical manifestations, pathologic features, prognosis and, management of Epstein-Barr virus-related SMT (EBV-SMT) in patients with AIDS. An English language literature search identified 53 articles including 64 reported cases of EBV-SMT. The majority of these reports involved patients who were young, severely immunosuppressed, and had multifocal tumors. The central nervous system was the most common site to be involved. Histologically, tumors had smooth muscle features and were immunoreactive for muscle markers and all but two tumors demonstrated the presence of EBV by either immunohistochemistry, in situ hybridization, and/or PCR. While mitoses and/or necrosis were used to separate leiomyoma from leiomyosarcoma, these features did not correlate with clinical outcome. Treatment included primarily resection, and less often radiotherapy, chemotherapy and highly active antiretroviral therapy (HAART). Overall, EBV-SMTs appear to have variable aggressiveness and clinical outcome and may exhibit a more favorable prognosis compared to conventional leiomyosarcoma. Tumor-related death from EBV-SMT occurred in only 4 of 51 patients
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