On Restricted Nonnegative Matrix Factorization

Nonnegative matrix factorization (NMF) is the problem of decomposing a given nonnegative $n \times m$ matrix $M$ into a product of a nonnegative $n \times d$ matrix $W$ and a nonnegative $d \times m$ matrix $H$. Restricted NMF requires in addition that the column spaces of $M$ and $W$ coincide. Finding the minimal inner dimension $d$ is known to be NP-hard, both for NMF and restricted NMF. We show that restricted NMF is closely related to a question about the nature of minimal probabilistic automata, posed by Paz in his seminal 1971 textbook. We use this connection to answer Paz's question negatively, thus falsifying a positive answer claimed in 1974. Furthermore, we investigate whether a rational matrix $M$ always has a restricted NMF of minimal inner dimension whose factors $W$ and $H$ are also rational. We show that this holds for matrices $M$ of rank at most $3$ and we exhibit a rank-$4$ matrix for which $W$ and $H$ require irrational entries.Comment: Full version of an ICALP'16 pape

Operation Strategies of a Solar Trigeneration Plant in a Residential Building

Actual trends of increased utilization of renewable sources in residential sector impose new requirements for domestic energy system operation. Recent research results have shown that a high level of energy autonomy could be achieved by the utilization of such systems in a residential building located within the European continental climate zone. That is particularly interesting in the light of the fact that in near future access to the hourly electricity market will be enabled to all households thus acting as prosumers. In this paper, the energy system comprising of a photovoltaic thermal collector, heat storage, heat pump and auxiliary energy sources, sized to cover the most of electricity, heating and cooling demand of a selected low-energy family house (180 m2 heated and cooled area, 75 m2 useful roof area, located in northwest Croatia) was considered. By analysis of yearly operational profiles, required exchange of energy on electricity market was estimated. Detailed mathematical model of the system was used for hourly simulation in order to evaluate impact of operational strategies on both renewable energy sources utilization and profitability. Two different control strategies were compared in typical days defined by profiles of energy demands, solar irradiance and electricity price. The simulation results showed how the change in operation strategy can reduce operational cost

Nonnegative Matrix Factorization Requires Irrationality

Nonnegative matrix factorization (NMF) is the problem of decomposing a given nonnegative $n \times m$ matrix $M$ into a product of a nonnegative $n \times d$ matrix $W$ and a nonnegative $d \times m$ matrix $H$. A longstanding open question, posed by Cohen and Rothblum in 1993, is whether a rational matrix $M$ always has an NMF of minimal inner dimension $d$ whose factors $W$ and $H$ are also rational. We answer this question negatively, by exhibiting a matrix for which $W$ and $H$ require irrational entries.Comment: Journal version, to appear in the SIAM Journal on Applied Algebra and Geometry (SIAGA

Enigma demencije Lewyjevih tjelešaca: prikaz slučaja

Lewy body dementia is a progressive neurodegenerative disease and is considered to be the second most common cause of dementia in the elderly. Because of the complexity of clinical presentation, it is often misdiagnosed and mistaken for other dementias, which may result in administering inappropriate therapy, and thus worsening of the patient condition. We reviewed a case of a 71-year-old patient whose clinical presentation gradually occurred with complex visual hallucinations, atypical extrapyramidal motor symptoms, fluctuating cognitive impairments with delirious episodes, and oscillating syncope. Depressive mood, impaired daily functioning and sensitivity to antipsychotics were also noted. Extensive diagnostic workup was performed with neuropsychological testing and use of single-photon emission computerized tomography. Considering the clinical presentation and diagnostic procedures performed, the diagnosis of Lewy body dementia was set and pharmacotherapy was revised. We discuss the importance of taking overall clinical presentation and diagnostic treatment in consideration and applying appropriate therapy to slow down the progression of the disease and exacerbation of the patient’s psychological functions.Demencija Lewyjevih tjelešaca je neurodegenerativna bolest i drugi najčešći uzročnik demencije u starijih osoba. Zbog složenosti kliničke slike često se pogrešno dijagnosticira i nerijetko zamijeni s drugim demencijama, što dovodi do primjene neodgovarajuće terapije, a time i pogoršanja stanja bolesnika. Prikazujemo slučaj bolesnika u dobi od 71 godine kod kojega se klinička slika postupno prezentirala složenim vizualnim halucinacijama, atipičnim ekstrapiramidnim motoričkim ispadima, fluktuirajućim kognitivnim smetnjama uz delirantne epizode i oscilirajuće sinkope. Kod bolesnika je zabilježeno depresivno raspoloženje, narušeno svakodnevno funkcioniranje i osjetljivost na psihofarmake. Provedena je opširna dijagnostička obrada uz neuropsihologijsko testiranje i primjenu jednofotonske emisijske tomografije. Na temelju kliničke slike i diferencijalno dijagnostičke obrade posumnjalo se na demenciju Lewyjevih tjelešaca. Raspravljamo o važnosti uzimanja u obzir cjelokupne kliničke slike i dijagnostičke obrade te primjeni odgovarajućeg liječenja u svrhu prevencije progresije bolesti i pogoršanja psihičkih funkcija bolesnika

Impact of pharmacotherapeutic education on medication adherence and adverse outcomes in patients with type 2 diabetes mellitus: a prospective, randomized study

Aim To evaluate the impact of pharmacotherapeutic education on 30-day post-discharge medication adherence and adverse outcomes in patients with type 2 diabetes mellitus (T2DM). Methods The prospective, randomized, single-center study was conducted at the Medical Department of University Hospital Dubrava, Zagreb, between April and June 2018. One hundred and thirty adult patients with T2DM who were discharged to the community were randomly assigned to either the intervention or the control group. Both groups during the hospital stay received the usual diabetes education. The intervention group received additional individual pre-discharge pharmacotherapeutic education about the discharge prescriptions. Medication adherence and occurrence of adverse outcomes (adverse drug reactions, readmission, emergency department visits, and death) were assessed at the follow-up visit, 30 days after discharge.Results The number of adherent patients was significantly higher in the intervention group (57/64 [89.9%] vs 41/61 [67.2%]; χ2 test, P = 0.003]. There was no significant difference between the groups in the number of patients who experienced adverse outcomes (31/64 [48.4%] vs 36/61 [59.0%]; χ2 test, P = 0.236). However, higher frequencies of all adverse outcomes were consistently observed in the control group. Conclusion Pharmacotherapeutic education of patients with T2DM can significantly improve 30-day post-discharge medication adherence, without a significant reduction in adverse clinical outcomes

The effectiveness of lixisenatide as an add on therapy to basal insulin in diabetic type 2 patients previously treated with different insulin regimes: a multi -center observational study

Introduction: This observational study aimed to assess the effectiveness of lixisenatide as add on therapy to basal insulin in diabetic type 2 patients previously treated with different insulin regimes. Methods: Patients with diabetes type 2, prescribed with lixisenatide and basal insulin were divided in three groups (premixed insulin, basal bolus insulin and basal oral therapy (BOT ). Difference in mean change in HbA1c, body mass index, total insulin doses, fasting blood glucose (FPG) and prandial blood glucose (PPG) were assessed after 3–6 ‑months of follow ‑up. Results: The primary outcomes were assessed in 111 patients. Lixisenatide added to basal insulin, reduced HbA1c and body weight significantly in all three groups of patients (p < 0.001 for all), with the most prominent reduction in the basal bolus group of patients which had the highest baseline HbA1c compared to premix and BOT treat ‑ ment groups. Regarding a difference in total insulin dose the reduction was statistically significant in the basal bolus (p = 0.006) and premix group (p < 0.001). FPG and PPG were also significantly reduced over time in all three groups (p < 0.001 for all). A composite outcome (reduction of HbA1c below 7% (53 mmol/mol) with any weight loss) was achieved in 27% of total patients included in the study, reduction of HbA1c below 7% was observed in 30% of patients, while 90% of patients experienced weight reduction. Conclusion: These results indicate that lixisenatide add on basal insulin treatment (BIT ) can improve glycemic con‑ trol in a population with long ‑standing type 2 diabetes and previously uncontrolled on other insulin therap

The Validity and Structure of Culture-Level Personality Scores: Data From Ratings of Young Adolescents

We examined properties of culture-level personality traits in ratings of targets (N=5,109) ages 12 to 17 in 24 cultures. Aggregate scores were generalizable across gender, age, and relationship groups and showed convergence with culture-level scores from previous studies of self-reports and observer ratings of adults, but they were unrelated to national character stereotypes. Trait profiles also showed cross-study agreement within most cultures, 8 of which had not previously been studied. Multidimensional scaling showed that Western and non-Western cultures clustered along a dimension related to Extraversion. A culture-level factor analysis replicated earlier findings of a broad Extraversion factor but generally resembled the factor structure found in individuals. Continued analysis of aggregate personality scores is warranted. This article is a US Government work and is in the public domain in the USA.Fil: McCrae, Robert R.. National Institute on Ageing; CanadáFil: Terracciano, Antonio. National Institute on Ageing; CanadáFil: De Fruyt, Filip. University of Ghent; BélgicaFil: De Bolle, Marleen. University of Ghent; BélgicaFil: Gelfand, Michele J.. University of Maryland; Estados UnidosFil: Costa Jr., Paul T.. National Institute on Ageing; CanadáFil: Klinkosz, Waldemar. The John Paul II Catholic University of Lublin; PoloniaFil: Knežević, Goran. Belgrade University; SerbiaFil: Leibovich de Figueroa, Nora. Universidad de Buenos Aires; ArgentinaFil: Löckenhoff, Corinna E.. Cornell University; Estados UnidosFil: Martin, Thomas A.. Susquehanna University; Estados UnidosFil: Marušić, Iris. Institute for Social Research; CroaciaFil: Mastor, Khairul Anwar. Universiti Kebangsaan Malaysia; MalasiaFil: Nakazato, Katsuharu. Iwate Prefectural University; AfganistánFil: Nansubuga, Florence. Makerere University; UgandaFil: Porrata, Jose. No especifíca;Fil: Purić, Danka. Belgrade University; SerbiaFil: Realo, aAnu. University of Tartu; EstoniaFil: Reátegui, Norma. Universidad Peruana Cayetano Heredia; PerúFil: Rolland, Jean Pierre. Universite Paris Ouest Nanterre la Defense; FranciaFil: Schmidt, Vanina Ines. Universidad de Buenos Aires. Facultad de Psicología. Instituto de Investigaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sekowski, Andrzej. The John Paul II Catholic University of Lublin; PoloniaFil: Shakespeare Finch, Jane. Queensland University of Technology; AustraliaFil: Shimonaka, Yoshiko. Bunkyo Gakuin University; JapónFil: Simonetti, Franco. Pontificia Universidad Católica de Chile; ChileFil: Siuta, Jerzy. Jagiellonian University;Fil: Szmigielska, Barbara. Jagiellonian University;Fil: Vanno, Vitanya. Srinakharinwirot University; TailandiaFil: Wang, Lei. Peking University; ChinaFil: Yik, Michelle. The Hong Kong University of Science and Technology; Hong Kon

CROATIAN GUIDELINES FOR THE PHARMACOTHERAPY OF TYPE 2 DIABETES

Uvod: Hrvatsko društvo za dijabetes i bolesti metabolizma Hrvatskoga liječničkog zbora izradilo je 2011. godine prve nacionalne smjernice o prehrani, edukaciji i samokontroli te farmakološkom liječenju šećerne bolesti tipa 2. Sukladno povećanom broju dostupnih lijekova te novim spoznajama o učinkovitosti i sigurnosti primjene već uključenih lijekova, pokazala se potreba za obnovom postojećih smjernica za farmakološko liječenje šećerne bolesti tipa 2 u Republici ­Hrvatskoj. Sudionici: Kao koautori Smjernica navedeni su svi članovi Hrvatskog društva za dijabetes i bolesti metabolizma Hrvatskoga liječničkog zbora, kao i ostalih uključenih stručnih društava, koji su svojim komentarima i prijedlozima pridonijeli izradi Smjernica. Dokazi: Ove su Smjernice utemeljene na dokazima, prema sustavu GRADE (engl. Grading of Recommendations, Assessment, Development and Evaluation) koji uz razinu dokaza opisuje i snagu preporuke. Zaključci: Individualan pristup temeljen na fiziološkim principima regulacije glikemije nuždan je u liječenju osoba sa šećernom bolesti. Ciljeve liječenja i odabir medikamentne terapije treba prilagoditi oboljeloj osobi, uzimajući u obzir životnu dob, trajanje bolesti, očekivano trajanje života, rizik od hipoglikemije, komorbiditete, razvijene vaskularne i ostale komplikacije, kao i ostale čimbenike. Zbog svega navedenoga od nacionalnog je interesa imati praktične, racionalne i provedive smjernice za farmakološko liječenje šećerne bolesti tipa 2.Introduction: The Croatian Association for Diabetes and Metabolic Disorders of the Croatian Medical Association has issued in 2011 the first national guidelines for the nutrition, education, self-control, and pharmacotherapy of ­diabetes type 2. According to the increased number of available medicines and new evidence related to the effectiveness and safety of medicines already involved in the therapy there was a need for update of the existing guidelines for the ­pharmacotherapy of type 2 diabetes in the Republic of Croatia. Participants: as co-authors of the Guidelines there are listed all members of the Croatian Association for Diabetes and Metabolic Diseases, as well as other representatives of professional societies within the Croatian Medical Association, who have contributed with comments and suggestions to the development of the Guidelines. Evidence: These guidelines are evidence-based, according to the GRADE system (eng. Grading of Recommendations, Assessment, Development and Evaluation), which describes the level of evidence and strength of recommendations. Conclusions: An individual patient approach based on physiological principles in blood glucose control is essential for diabetes’ patients management. Glycemic targets and selection of the pharmacological agents should be tailored to the patient, taking into account the age, duration of disease, life expectancy, risk of hypoglycemia, comorbidities, developed vascular and other complications as well as other factors. Because of all this, is of national interest to have a practical, rational and applicable guidelines for the pharmacotherapy of type 2 diabetes

Hrvatske smjernice za farmakološko liječenje šećerne bolesti tipa 2 [Croatian guidelines for the pharmacotherapy of type 2 diabetes]

Introduction: The Croatian Association for Diabetes and Metabolic Disorders of the Croatian Medical Association has issued in 2011 the first national guidelines for the nutrition, education, self-control, and pharmacotherapy of diabetes type 2. According to the increased number of available medicines and new evidence related to the effectiveness and safety of medicines already involved in the therapy there was a need for update of the existing guidelines for the pharmacotherapy of type 2 diabetes in the Republic of Croatia. Participants: as co-authors of the Guidelines there are listed all members of the Croatian Association for Diabetes and Metabolic Diseases, as well as other representatives of professional societies within the Croatian Medical Association, who have contributed with comments and suggestions to the development of the Guidelines. Evidence: These guidelines are evidence-based, according to the GRADE system (eng. Grading of Recommendations, Assessment, Development and Evaluation), which describes the level of evidence and strength of recommendations. Conclusions: An individual patient approach based on physiological principles in blood glucose control is essential for diabetes' patients management. Glycemic targets and selection of the pharmacological agents should be tailored to the patient, taking into account the age, duration of disease, life expectancy, risk of hypoglyce- mia, comorbidities, developed vascular and other complications as well as other factors. Because of all this, is of national interest to have a practical, rational and applicable guidelines for the pharmacotherapy of type 2 diabetes

Nonfinancial Reporting in the Croatia Hotel Industry - Case Study of Valamar Riviera Plc.

Sve veća briga o okolišu i društvu dovodi do transparentnosti i potrebe da poduzeća i organizacije budu transparentne. Nefinancijsko izvješćivanje igra veliku ulogu u prezentiranju informacija povezanih s okolišem i zaposlenicima. Danas se više nego ikad iznimno cijene poduzeća koja pridaju brigu održivom razvoju i koja nastoje poslovati i razvijati se na održiv način. Isto tako, veoma se cijeni činjenica da se poduzeća i organizacije ne boje prikazati kako posluju, kako u financijskom tako i nefinancijskom aspektu. Bolja kvaliteta izvještaja svakako olakšava rad svim zaposlenima u poduzeću, ali i dionicima i svima ostalima. Ovaj je rad usmjeren upravo na važnost nefinancijskih izvještaja i jedan primjer veoma dobre prakse, Valamar Riviera d.d. koji je jedan od vodećih poduzeća u Republici Hrvatskoj koji transparentno predstavlja sve svoje informacije i ciljeve vezane uz okoliš i zaposlenike