Spletni priporočilni sistem za filmske vsebine

Cilj diplomskega dela je bil izdelava spletnega priporočilnega sistema (ang. recommender systems) za filme in njegovo ovrednotenje. Odločili smo se za pristop s skupinskim filtriranjem (ang. collaborative filtering), ki temelji na sodelovanju uporabnikov s podobnim okusom. Za aktivnega uporabnika se poišče njemu podobne uporabnike – najbližje sosede, ki smo jih poimenovali filmski prijatelji. Le-ti s svojim okusom po metodi utežene vsote vplivajo na napoved ocene filma. V prvem delu naloga obsega teoretični del, v katerem so predstavljeni osnovni pojmi in gradniki priporočilnih sistemov. Osrednji del diplomske naloge se posveča praktični izvedbi, kjer je bila izdelana lastna podatkovna baza s 47-imi uporabniki in z naborom 22-ih filmov različnih žanrov, ki so jih uporabniki ocenili s pomočjo 7-stopenjske lestvice (ocene od −3 do 3). Zaradi premajhne zapolnjenosti baze uporabniki : filmi se je sistemu dodalo na spletu dosegljivo podatkovno bazo MovieLens, s čimer se je povečal nabor filmov, ki jih priporočilni sistem priporoča uporabnikom. Iz MovieLensa je bilo izluščenih 83 uporabnikov, ki so ocenili vseh 22 filmov iz nabora. Tako je bilo doseženo zadostno število potrebnih podatkov za zagotovitev delovanja priporočilnega sistema in njegovega ovrednotenja. MovieLens podatkovno bazo smo izkoristili za priporočanje dodatnih filmov, ki jih je omogočil najboljši filmski prijatelj (iz MovieLensa) aktivnega uporabnika (iz naše lastne podatkovne baze), vendar tega dela ni bilo mogoče ovrednotiti. Za ovrednotenje priporočilnega sistema (83 uporabnikov iz MovieLens baze) sta bili uporabljeni dve metodi, in sicer povprečna absolutna napaka MAE (ang. Mean Absolute Error) in mera F (ang. F-measure). MAE je pri največji pokritosti 99,95 % dosegla najnižjo vrednost 0,77 pri mejah Pearsonove korelacije −0,1 in 0,05. V nadaljevanju smo vzeli vrednost števila sosedov pri meji Pearsonove korelacije 0,05 in jo uporabili pri izračunu mere F. Predpostavili smo, da sistem aktivnemu uporabniku priporoči le filme z najvišjo oceno (ocena 3), kar je dalo naslednje rezultate: natančnost 0,743, priklic 0,407 in mera F 0,526. Bistven podatek za ovrednotenje sistema je natančnost, ki določa delež pravilno priporočenih vsebin izmed vseh priporočenih vsebin. Torej sistem pravilno priporoča skoraj 75 % vseh priporočenih vsebin, kar je zadovoljiv podatek in bi sistem lahko uporabili v praksi. Priklic pomeni delež pravilno priporočenih vsebin izmed vseh, ki bi morali biti priporočeni, a niso bili zajeti v priporočila. Priklic je dal nižje rezultate, kar je vplivalo na rezultat mere F, ki je zato nižja, kot bi si želeli.The aim of this thesis was to develop and evaluate an online recommender system for movies. We selected a collaborative filtering approach based on the opinion of users with similar tastes. First, it was necessary to find users similar to the active user – the nearest neighbours, termed the movie\u27s friends. Their preferences influence the prediction of the movie rating of the active user according to the weighted sum method. The introduction of the thesis presents the theory of the basic concepts and elements of recommender systems. The main part focuses on the practical implementation. A database of 47 users and a set of 22 movies of different genres were created. Users rated movies on a 7-point scale (rating of -3 to 3). Because the database users : movies was insufficiently filled, the Internet-accessible database MovieLens was added to our system, increasing the number of films recommended to our users. Furthermore, 83 users who rated all 22 films from our set were extracted from the MovieLens database. We thereby obtained sufficient data to ensure the proper functioning of the recommender system and its evaluation. The movie’s best friend from the MovieLens database also recommended additional movies to the active user from our database. However, we were unable to evaluate that function. To evaluate the recommender system (83 users from the MovieLens database), we used two methods: the average absolute error MAE and the F-measure. At the maximum coverage of 99.95 %, the MAE reached the lowest value of 0.77 (Pearson correlation values of -0.1 and 0.05). The Pearson correlation value of 0.05 (for the number of neighbours) was used to calculate the F-measure. It was assumed that the system would recommend only the movies with the highest rating to the active user (rating 3), yielding the following results: precision 0.743, recall 0.407 and F-measure 0.526. The most important information for evaluating the recommender system is precision, which determinates the percentage of accurate recommendations from all recommendations given by the system. The research showed that almost 75 % of all recommended movies were accurately recommended to the active users. Therefore, this recommender system can be used in practice. However, the recall was lower than we expected, which influenced the F-measure

Synthesis of pyrrolin-4-one derivatives and their application in organocatalyzed reactions

Iz poceni in lahko dostopnih gradnikov sem pripravil različne benzilidenske pirolin-4-onske derivate z namenom uporabe v nadaljnjih stereoselektivnih organokataliziranih reakcijah. Kljub temu, da je sinteza podobnih spojin literaturno opisana, so se sinteze benzaldehidnih derivatov pirolin-4-onov izkazale za težavne. Uspešno sem optimiziral sintezo benzilidiranih pirolin-4-onov, kar omogoča enostavno pripravo večjih količin teh spojin. Izvedel sem dvostopenjsko enolončno organokatalizirano asimetrično sulfa-Michaelovo/aldolno kaskadno reakcijo. Raznovrstne arilidenske pirolin-4-one sem v prisotnosti kininskega organokatalizatorja reagiral z 1,4-ditian-2,5-diolom do nastanka ustreznih spirocikličnih pirolin-4-onov. Reakcija omogoča tvorbo treh stereogenih centrov od tega je en kvarterni spirostereocenter. Reakcija se je izkazala z relativno visoko diastereoselektivnostjo (73:15:12 – 93:7 d.r.) in enantioselektivnostjo (66 % – >99 % e.e.). Reakcijo tvorbe spirocikličnih pirolin-4-onov sem preizkusil tudi z drugimi, manj pogosto uporabljenimi kininskimi organokatalizatorji. Z njimi in dodatnimi kontrolnimi eksperimenti sem preveril vpliv različnih načinov izolacije na končni enantiomerni presežek produkta.Starting from cheap, easily available building blocks, different benzylidene pyrrolin-4-one derivatives were prepared for the application in stereoselective organocatalyzed reactions. Although the synthesis of similar compounds was known from the literature, much effort was employed to successfully optimize synthesis of various benzylidene pyrrolin-4-one derivatives. Under optimized reaction conditions large scale preparation of benzylidenic pyrrolin-4-one heterocycles was enabled. One-pot two-step organocatalyzed asymmetric sulfa-Michael/aldol cascade reactions were performed. Various arylidene pyrrolin-4-one derivatives were reacted with 1,4-ditian-2,5-diol in the presence of a quinine organocatalyst. The product of this reaction were new spirocyclic pyrrolin-4-ones. The reaction enables the construction of three new stereocenters, one of which is a quaternary spiro-stereocenter. Reactions proceeded with relatively high diastereoselectivity (73:15:12 – 93:7 d.r.) and enantioselectivity (66 % – >99 % e.e.). Formation of novel spirocyclic pyrrolin-4-ones was tested also with additional, less frequently applied quinine organocatalysts. With this additional organocatalysts and control experiments, the effect on enantiomeric excess under different isolation procedures was investigated

Do emotion regulation and impulsivity differ according to gambling preferences in clinical samples of gamblers?

BACKGROUND AND AIMS: Emotion regulation (ER) and impulsivity impairments have been reported in patients with gambling disorder (GD). However, both constructs have not been studied in depth jointly in clinical samples. Therefore, the aim of this study was to analyze ER and impulsive tendencies/traits in a sample of n = 321 treatment-seeking individuals with GD by differentiating them according to their gambling preference (n = 100 strategic; n = 221 non-strategic). METHODS: Our sample was assessed through the DERS (ER), the UPPS-P (impulsivity), and the DSM-5 (GD severity). RESULTS: The non-strategic group included a higher proportion of women and reported greater ER impairments, and more impulsive traits/tendencies compared to strategic gamblers. GD severity was associated with all DERS subscale (except for awareness) and with urgency dimensions of the UPPS-P. DISCUSSION AND CONCLUSIONS: Our findings confirm that strategic and non-strategic gamblers differ in their ER processes and impulsive tendencies, showing the first clinical group a more adaptive profile. These results suggest the relevance of assessing these ER and impulsivity in order to tailor better treatment approaches

Identifying Factors Influencing Attention in Adolescents with a Co-Created Questionnaire : A Citizen Science Approach with Secondary Students in Barcelona, Spain

Studies on factors that can influence attention in healthy adolescents are recent and focus on recurrent topics. Students' contribution to public health research often revolves around collecting data but rarely around creating data collection instruments. The ATENC!Ó project reunited secondary students and scientists to create a questionnaire including factors that students thought could affect their attention. We conducted a cross-sectional study to assess whether the factors included in this questionnaire had an effect on attention in adolescents. A total of 1667 students (13-16 years old) from 28 schools in Barcelona performed a validated attention test and answered the questionnaire. The response speed consistency (attentiveness), expressed as hit reaction time standard error (HRT-SE, in ms), was used as the primary outcome. Analyses were conducted using conditional linear regression with school as strata, adjusted for sociodemographic characteristics and further stratified by gender and maternal social class. Some factors showed a negative influence on attention, including taking medication and not reading regularly. We found a significant 14.3% (95% confidence interval: 3.4%, 25.3%) higher median of HRT-SE (increase inattentiveness) among students who reported not having a good relationship with classmates. Students' input into research is relevant for advancing the knowledge production in public health

The Gaze Fixation Assessed by Microperimetry: A Useful Tool for the Monitoring of the Cognitive Function in Patients with Type 2 Diabetes

Cognitive impairment; Retinal microperimetry; Type 2 diabetesDeterioro cognitivo; Microperimetría retiniana; Diabetes tipo 2Deteriorament cognitiu; Microperimetria retiniana; Diabetis tipus 2Current guidelines recommend annual screening for cognitive impairment in patients > 65 years with type 2 diabetes (T2D). The most used tool is the mini-mental state evaluation (MMSE). Retinal microperimetry is useful for detecting cognitive impairment in these patients, but there is no information regarding its usefulness as a monitoring tool. We aimed to explore the role of retinal microperimetry in the annual follow-up of the cognitive function of patients with T2D older than 65 years. Materials and Methods: Prospective observational study, comprising patients > 65 years with T2D, attended at our center between March–October 2019. A complete neuropsychological evaluation assessed the baseline cognitive status (mild cognitive impairment, MCI, or normal, NC). Retinal microperimetry (sensitivity, gaze fixation) and MMSE were performed at baseline and after 12 months. Results: Fifty-nine patients with MCI and 22 NC were identified. A significant decline in the MMSE score was observed after 12 months in the MCI group (25.74 ± 0.9 vs. 24.71 ± 1.4; p = 0.001). While no significant changes in retinal sensitivity were seen, all gaze-fixation parameters worsened at 12 months and significantly correlated with a decrease in the MMSE scores. Conclusion: Retinal microperimetry is useful for the monitoring of cognitive decline in patients > 65 years with T2D. Gaze fixation seems a more sensitive parameter for follow-up after 12 months than retinal sensitivity.This study was supported by grants from the Instituto de Salud Carlos III (Fondo de Investigación Sanitaria, PI20/01703). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Prevalence of Suicidal Behavior and Associated Clinical Correlates in Patients with Behavioral Addictions

Addictive disorders are characterized by severe consequences, including suicidal events, but most studies investigating the association between addiction and suicidal risk have focused on substance use disorders and gambling disorder at the expense of the rest of behavioral addictions. This study examined the prevalence and the associated clinical correlates of suicidal ideation and suicide attempts in a sample of patients with a diagnosis of behavioral addiction. The total sample consisted of 4404 individuals: 4103 of these patients with gambling disorder, 99 with gaming disorder, 44 with sex addiction, and 158 with buying-shopping disorder. All of them were assessed consecutively at a specialized hospital unit for the treatment of behavioral addictions. Participants attended two clinical interviews and completed self-reported questionnaires to explore clinical features of behavioral addictions, personality traits, psychopathological symptomatology, suicidal behavior, and sociodemographic variables. The highest prevalence of suicidal ideation was found in patients with gambling disorder (22.9%), followed by buying-shopping disorder (18.4%), sex addiction (18.2%), and gaming disorder (6.1%). The highest prevalence of suicide attempts was registered for sex addiction (9.1%), followed by buying-shopping disorder (7.6%), gambling disorder (6.7%), and gaming disorder (3.0%). Female gender and unemployment constituted two relevant sociodemographic factors associated with suicidal risk in gambling disorder, gaming disorder, and buying-shopping disorder. Lack of family support appeared as a relevant risk factor, except for gaming disorder. These results pointed out that suicide is a prevalent behavior in behavioral addictions, and clinicians and researchers need to pay particular attention to the specificities of each behavioral addiction when assessing suicidal risk

The Gaze Fixation Assessed by Microperimetry : A Useful Tool for the Monitoring of the Cognitive Function in Patients with Type 2 Diabetes

Current guidelines recommend annual screening for cognitive impairment in patients > 65 years with type 2 diabetes (T2D). The most used tool is the mini-mental state evaluation (MMSE). Retinal microperimetry is useful for detecting cognitive impairment in these patients, but there is no information regarding its usefulness as a monitoring tool. We aimed to explore the role of retinal microperimetry in the annual follow-up of the cognitive function of patients with T2D older than 65 years. Materials and Methods: Prospective observational study, comprising patients > 65 years with T2D, attended at our center between March-October 2019. A complete neuropsychological evaluation assessed the baseline cognitive status (mild cognitive impairment, MCI, or normal, NC). Retinal microperimetry (sensitivity, gaze fixation) and MMSE were performed at baseline and after 12 months. Results: Fifty-nine patients with MCI and 22 NC were identified. A significant decline in the MMSE score was observed after 12 months in the MCI group (25.74 ± 0.9 vs. 24.71 ± 1.4; p = 0.001). While no significant changes in retinal sensitivity were seen, all gaze-fixation parameters worsened at 12 months and significantly correlated with a decrease in the MMSE scores. Conclusion: Retinal microperimetry is useful for the monitoring of cognitive decline in patients > 65 years with T2D. Gaze fixation seems a more sensitive parameter for follow-up after 12 months than retinal sensitivity

BMP8B increases brown adipose tissue thermogenesis through both central and peripheral actions

Thermogenesis in brown adipose tissue (BAT) is fundamental to energy balance and is also relevant for humans. Bone morphogenetic proteins (BMPs) regulate adipogenesis, and, here, we describe a role for BMP8B in the direct regulation of thermogenesis. BMP8B is induced by nutritional and thermogenic factors in mature BAT, increasing the response to noradrenaline through enhanced p38MAPK/CREB signaling and increased lipase activity. Bmp8b(-/-) mice exhibit impaired thermogenesis and reduced metabolic rate, causing weight gain despite hypophagia. BMP8B is also expressed in the hypothalamus, and Bmp8b(-/-) mice display altered neuropeptide levels and reduced phosphorylation of AMP-activated protein kinase (AMPK), indicating an anorexigenic state. Central BMP8B treatment increased sympathetic activation of BAT, dependent on the status of AMPK in key hypothalamic nuclei. Our results indicate that BMP8B is a thermogenic protein that regulates energy balance in partnership with hypothalamic AMPK. BMP8B may offer a mechanism to specifically increase energy dissipation by BAT