946 research outputs found

    Packing dimension of mean porous measures

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    We prove that the packing dimension of any mean porous Radon measure on Rd\mathbb R^d may be estimated from above by a function which depends on mean porosity. The upper bound tends to d1d-1 as mean porosity tends to its maximum value. This result was stated in \cite{BS}, and in a weaker form in \cite{JJ1}, but the proofs are not correct. Quite surprisingly, it turns out that mean porous measures are not necessarily approximable by mean porous sets. We verify this by constructing an example of a mean porous measure μ\mu on R\mathbb R such that μ(A)=0\mu(A)=0 for all mean porous sets ARA\subset\mathbb R.Comment: Revised versio

    Determinants of OSS revenue model choices

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    The open source software movement is traditionally not affiliated to profit-oriented business behaviour. However, commercial activity has become increasingly common, and, business models have institutionalized in the field of open source software. The aim of this research paper is to explore the determinants of profitable revenue models for businesses based on open source software. Therefore, the study focuses on analysing different revenue options of open source software businesses as a part of more comprehensive open source software (OSS) business models. We explore other business model elements as the potential determinants of firm-level revenue model choices. This study draws on a qualitative research approach on the issue through two analytical business cases – MySQL and Red Hat – both of which illustrate the complexity and heterogeneity of solutions and options in the field of OSS. Thus, we analyse the business models of the selected case companies and identify the underlying endogenous elements, i.e. offerings, resources and relationships within them. Finally, we discuss the managerial implications derived from the cases to describe how these business model elements affect the development of successful revenue models in the field of open source software

    Potential of consumer EEG for real-time interactions in immersive VR

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    Abstract. Virtual reality is an active research subject and has received a lot of attention over the last few years. We have seen multiple commercial VR devices, each improving upon the last iteration become available to the wider public. In addition, interest in brain-computer interface (BCI) devices has increased rapidly. As these devices are becoming more affordable and easy to use, we are presented with more accessible options to measure brain activity. In this study, our aim is to combine these two technologies to enhance the interaction within a virtual environment. In this study we sought to facilitate interaction in VR by using EEG signals. The EEG signals were used to estimate the volume of focus. By applying this concept with VR, we designed two use cases for further exploration. The methods of interactions explored in the study were telekinesis and teleportation. Telekinesis seemed an applicable option for this study since it allows the utilization of the EEG while maintaining a captivating and engaging user experience. With teleportation, the goal was the exploration of different options for locomotion in VR. To test our solution, we built a test environment by using Unity engine. We also invited several participants to gain feedback on the usability and accuracy of our methodology. For evaluation, 13 study participants were divided into two different groups. The other group tested our actual solution for the estimation of the focus. However, the other group used randomized values for the same purpose. Some key differences between the test groups were identified. We were able to create a working prototype where the users could interact with the environment by using their EEG signals. With some improvements, this could be expanded to a more refined solution with a better user experience. There is a lot of potential in combining the use of human brain signals with virtual environments to both enrich the interaction and increase the immersion of virtual reality.Kuluttaja-EEG laitteiden potentiaali reaaliaikaiseen vuorovaikutukseen immersiivisessä virtuaalitodellisuudessa. Tiivistelmä. Virtuaalitodellisuus (VR) on aktiivisen tutkimuksen kohde ja varsinkin viime vuosina herättänyt paljon huomiota. VR-laseissa on tapahtunut huomattavaa kehitystä ja niitä on saatavilla yhä laajemmalle käyttäjäkunnalle. Lisäksi kiinnostus aivo-tietokone -rajapintoihin (BCI) on kiihtymässä. Koska aivokäyrää mittaavat laitteet ovat yhä edullisempia ja kehittymässä helppokäyttöisemmiksi, monia uusia menetelmiä aivosignaalin mittamiseksi on saatavilla. Tässä työssä tavoitteemme oli yhdistää nämä kaksi teknologiaa parantaaksemme vuorovaikutusta virtuaalitodellisuudessa. Tässä tutkimuksessa käytimme aivosähkökäyrää VR-käyttäjäkokemuksen kehittämiseksi. Tätä tekniikkaa hyödyntäen arvioimme käyttäjän keskittymistä. Tutkimusta varten valitsimme kaksi vuorovaikutustapaa. Nämä tutkittavat tavat ovat telekinesia sekä teleportaatio. Telekinesia on mielenkiintoinen tapa hyödyntää aivosähkökäyrää luoden samalla mukaansatempaavan käyttäjäkokemuksen. Teleportaation päämääränä oli löytää uudenlaisia liikkumistapoja VR:ssä. Tutkimustamme varten, suunnittelimme testiympäristön Unity-pelimoottorilla. Kokosimme joukon testaajia, joiden avulla arvioimme työmme käyttökelpoisuutta sekä tarkkuutta. Saadaksemme luotettavampia testituloksia, jaoimme 13 testaajaa kahteen eri ryhmään. Toinen ryhmistä testasi varsinaista toteutustamme ja toinen ryhmä käytti satunnaistettuja keskittymisarvoja. Löysimme ratkaisevia eroja näiden kahden testiryhmän välillä. Onnistuimme kehittämään toimivan prototyypin, jossa käyttäjät kykenivät interaktioon virtuaaliympäristössä hyödyntäen aivosähkökäyrää. Jatkokehitystä tekemällä käyttäjäkokemusta olisi mahdollista parantaa entisestään. Integraatio aivosensoreiden ja virtuaalitodellisuuden välillä huokuu potentiaalia ja tarjoaa mahdollisuuksia tehdä virtuaalimaailmasta yhä immersiivisemmän

    Kokemuksia haastavista ja kuormittavista tilanteista varhaiskasvattajien työssä

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    Opinnäytetyön lisäosan tarkoituksena oli selvittää, millaisia haastavia ja kuormittavia tilanteita varhaiskasvattajat voivat kohdata työssään lasten, huoltajien, työyhteisön ja muiden tilanteiden parissa. Tutkimustehtävä keskittyi erityisesti siihen, millä tavalla haasteisiin voidaan vaikuttaa ja millaisiin tilanteisiin varhaiskasvattajat kokevat itse pystyvänsä vaikuttamaan ja millaisiin eivät. Tutkielmassa käsiteltiin myös varhaiskasvattajien kokemia työn voimavaroja, jotka osaltaan tukevat varhaiskasvattajien työssä jaksamista. Tutkielmassa vertailtiin varhaiskasvattajien ja muskariopettajien kokemuksien samankaltaisuuksia, koska tämä tutkielma täydensi aikaisempaa musiikkipedagogin (AMK) opinnäytetyötäni (Mäkipelto 2014). Teoreettinen viitekehys muodostui tässä tutkielmassa työhyvinvointiin liittyvästä kirjallisuudesta ja aikaisemmasta tutkimuksesta, joissa tarkasteltiin työkäytäntöjen ja työn voimavara- ja kuormitustekijöiden vaikutuksia työhyvinvointiin. Tutkielma toteutettiin kvalitatiivisena eli laadullisena tutkimuksena ja tutkimusmenetelmänä käytettiin puolistrukturoitua teemahaastattelua. Teemahaastattelu analysoitiin teemoittelun ja aineistolähtöisen sisällönanalyysin avulla. Yhteistyökumppanina oli Norlandia päiväkodit. Haastatteluun osallistui neljä varhaiskasvattajaa, joiden kokemukset eivät liittyneet ainoastaan nykyiseen työpaikkaan Norlandian päiväkodissa, vaan ne koskivat myös aikaisempaa työhistoriaa. Tutkimustulokset osoittivat, että haastavat ja kuormittavat kokemukset liittyivät erityisesti lapsiryhmän hallintaan, huoltajien kohtaamiseen, työyhteisön ristiriitoihin, työn ulkopuoliseen elämään ja työnkuvaan liittymättömiin tilanteisiin kuten siivoamiseen. Ongelmanratkaisukeinoiksi nimettiin lasten parissa tunteiden käsittely ja rauhallinen vuorovaikutus. Varhaiskasvattajat kokivat, että huoltajien parissa auttoi kunnioittava suhtautuminen ja säännöllinen tiedottaminen. Työyhteisössä korostui yhteisten sääntöjen, kommunikoinnin ja toimivan johtajuuden merkitys. Muissa tilanteissa painotettiin työn ulkopuolisesta elämästä huolehtimista. Varhaiskasvattajat kokivat, että lasten perheoloihin ja resurssien puutteeseen he eivät pystyneet vaikuttamaan. Työn voimavaroina painottui lasten riemu ja kehitys, toimiva yhteistyö huoltajien ja työyhteisön parissa sekä oman työn kehittäminen, arvostaminen ja rajaaminen. Edeltävissä tuloksissa oli paljon yhteneväisyyksiä aikaisempien tutkimustulosten kanssa. Varhaiskasvattajat ja muskariopettajat olivat kokeneet yhtäläisiä haastavia tilanteita erityisesti lapsiryhmän hallintaan, huoltajien kohtaamiseen ja työyhteisössä heikkoon perehdytykseen ja sääntöjen epäselvyyteen liittyvissä tilanteissa. Ongelmanratkaisukeinoina korostui molemmissa ammattiryhmissä lasten parissa keskusteleminen, yhteisten sääntöjen, periaatteiden ja toimintatapojen vahvistaminen. Varhaiskasvattajat ja muskariopettajat kokivat lasten riemun ja työkavereiden tuen voimavaraksi. Johtopäätöksistä ilmeni, että varhaiskasvattajien ja muskariopettajien työssä korostui vuorovaikutuksen merkitys. Mikäli vuorovaikutus oli heikkoa, se aiheutti enemmän kuormitusta. Jos vuorovaikutus toimi, yhteisöllisyys lisääntyi ja toimi voimavarana. Jatkossa voitaisiin tutkia enemmän erityisesti työn ulkopuolisen elämän yhteyttä varhaiskasvattajien hyvinvointiin ja moniammatillisten varhaiskasvattajien erilaisia kokemuksia. Niiden merkitys korostui tässä tutkielmassa ja aikaisemmissa tutkimuksissa.The purpose of the supplementary thesis was to find out what kind of challenging and stressful situations early childhood educators may face in their work with children, guardians, the work community and other situations. The aim was to find ways to influence the challenges and find out which situations early childhood educators feel themselves capable of influencing and which not. The thesis focused also on the strengthening factors experienced by early childhood educators, which contribute to the well-being of early childhood educators. Moreover, the thesis compares similarities between the experiences of early childhood educators and music playschool teachers as this thesis complements my earlier bachelor’s thesis in early childhood music education (Mäkipelto 2014). The theoretical framework of this thesis consists of occupational well-being literature and earlier studies, which examined the effects of work practices and work strength and stress factors on occupational well-being. The thesis was carried out as qualitative research and a semi-structured thematic interview was used as the research method. The thematic interview was analyzed with theme and content analysis. The cooperation partner was Norlandia Päiväkodit. Four early childhood educators participated in the interview. Their experiences were not only related to the current job at the Norlandia kindergarten, but also on past work history. The results demonstrated that challenging and stressful experiences were especially related to group management with children, the interaction with guardians, conflicts in the work community, life outside the workplace, and work assignment issues not included in the job description such as cleaning. Problem solving included emotional management and peaceful interaction with children. Early childhood educators felt that respect and regular information helped with guardians. In the work community the importance of common rules, communication and effective leadership were emphasized. The life outside of work was emphasized in other situations. Early childhood educators felt that they were unable to influence children's family conditions and lack of resources. The work strength-factors consisted of the joy and development of children, effective cooperation with guardians and the work community, as well as the development, appreciation and delimitation of their own work. These results had several similarities with previous research results. Early childhood educators and music playschool teachers had experienced similar challenging situations, especially in the group management with children, the interactions with guardians, and in the work community in situations involving weak orientation and unclear rules. Both professional groups solved problems by discussing with children and enforcing common rules and principles. Both professional groups felt that the joy of children and support from colleagues strengthened their work resources. The study concluded that interaction is important for both early childhood educators and music playschool teachers. If interaction was weak, it caused more stress. If it worked, communality increased and it served as a strength factor. The occupational wellbeing of early childhood educators could be studied further by focusing on life-factors outside work and a multi-professional perspective. The importance of these perspectives was emphasized in this thesis and former studies

    Use of heavy metals in swine feed and its association with the co-selection of metal tolerant and multi-drug resistant Salmonella

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    This study was conducted to characterize the role of chemical interventions, biocides and heavy metal micronutrients, in particular, in swine production systems on the emergence of heavy metal and biocide tolerant Salmonella and its association with antimicrobial resistance. A total of 353 Salmonella isolates with different antimicrobial resistance profiles identified from 36 barns exposed to three different classes of biocides were analyzed. The sources of isolates included feed (n=30), fecal (n=226), and environment (n=97) samples that were systematically selected

    The in vitro effects of resistin on the innate immune signaling pathway in isolated human subcutaneous adipocytes

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    Context: Obesity-associated inflammation is a contributory factor in the pathogenesis of type 2 diabetes mellitus (T2DM); the mechanisms underlying the progression to T2DM are unclear. The adipokine resistin has demonstrated pro-inflammatory properties in relation to obesity and T2DM. Objective: To characterize resistin expression in human obesity and address the role of resistin in the innate immune pathway. Furthermore, examine the influence of lipopolysaccharide, recombinant human resistin (rhResistin), insulin and rosiglitazone in human adipocytes. Finally, analyze the effect of rhResistin on the expression of components of the NF-κB pathway and insulin signaling cascade. Methods: Abdominal subcutaneous adipose tissue was obtained from patients undergoing elective liposuction surgery (n = 35, aged: 36-49 yr; BMI: 26.5 ± 5.9 kg/m2). Isolated adipocytes were cultured with rhResistin (10-50 ng/ml). The level of cytokine secretion from isolated adipocytes was examined by ELISA. The effect of rhResistin on protein expression of components of the innate immune pathway was examined by Western blot. Results: In-vitro studies demonstrated that antigenic stimuli increase resistin secretion (P < 0.001) from isolated adipocytes. Pro-inflammatory cytokine levels were increased in response to rhResistin (P < 0.001); this was attenuated by rosiglitazone (P < 0.01). When examining components of the innate immune pathway, rhResistin stimulated Toll-like receptor-2 protein expression. Similarly, mediators of the insulin signaling pathway, phosphospecific JNK1 and JNK2, were upregulated in response to rhResistin. Conclusion: Resistin may participate in more than one mechanism to influence pro-inflammatory cytokine release from human adipocytes; potentially via the integration of NF-κB and JNK signaling pathways

    Effective Digital Channel Marketing for Cybersecurity Solutions

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    Smaller organizations are prime targets for hackers and malware, because these businesses lack cybersecurity plans and the resources to survive a serious security incident. To exploit this market opportunity, cybersecurity solution providers need to leverage the power of downstream channel members. We investigate how a supplier's digital channel marketing can encourage value-added resellers to sell that supplier’s cybersecurity solutions. Our analysis of survey data from 109 value-added resellers of a multinational supplier shows that resellers are more committed to stock and sell cybersecurity products and services if the supplier’s digital channel marketing provides tools that help them sell the solutions to end customers. This support is likely needed because cybersecurity offerings are technologically complex and systemic by nature, as supported by the finding that value-added resellers pay little attention to supplier’s campaigns and price discounts. Thus, cybersecurity suppliers should maintain trusted and informative relationships with their resellers and provide them with hands-on sales tools, because a reseller's commitment to selling cybersecurity solutions is linked with their ability to understand the offering and with the extent of their supplier relationship. These findings are in line with previous literature on the challenges perceived by salespeople in selling novel and complex technology

    Marked deterioration in the quality of life of patients with idiopathic pulmonary fibrosis during the last two years of life

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    BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic disease with a high symptom burden and poor survival that influences patients' health-related quality of life (HRQOL). We aimed to evaluate IPF patients' symptoms and HRQOL in a well-documented clinical cohort during their last two years of life.MethodsIn April 2015, we sent the Modified Medical Research Council Dyspnea Scale (MMRC), the modified Edmonton Symptom Assessment Scale (ESAS) and a self-rating HRQOL questionnaire (RAND-36) to 300 IPF patients, of which 247 (82%) responded. Thereafter, follow-up questionnaires were sent every six months for two years.ResultsNinety-two patients died by August 2017. Among these patients, HRQOL was found to be considerably low already two years before death. The most prominent declines in HRQOL occurred in physical function, vitality, emotional role and social functioning (pPeer reviewe

    Calculus and heat flow in metric measure spaces and applications to spaces with Ricci bounds from below

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    This paper is devoted to a deeper understanding of the heat flow and to the refinement of calculus tools on metric measure spaces (X,d,m). Our main results are: - A general study of the relations between the Hopf-Lax semigroup and Hamilton-Jacobi equation in metric spaces (X,d). - The equivalence of the heat flow in L^2(X,m) generated by a suitable Dirichlet energy and the Wasserstein gradient flow of the relative entropy functional in the space of probability measures P(X). - The proof of density in energy of Lipschitz functions in the Sobolev space W^{1,2}(X,d,m). - A fine and very general analysis of the differentiability properties of a large class of Kantorovich potentials, in connection with the optimal transport problem. Our results apply in particular to spaces satisfying Ricci curvature bounds in the sense of Lott & Villani [30] and Sturm [39,40], and require neither the doubling property nor the validity of the local Poincar\'e inequality.Comment: Minor typos corrected and many small improvements added. Lemma 2.4, Lemma 2.10, Prop. 5.7, Rem. 5.8, Thm. 6.3 added. Rem. 4.7, Prop. 4.8, Prop. 4.15 and Thm 4.16 augmented/reenforced. Proof of Thm. 4.16 and Lemma 9.6 simplified. Thm. 8.6 corrected. A simpler axiomatization of weak gradients, still equivalent to all other ones, has been propose

    Novel ZNF414 activity characterized by integrative analysis of ChIP-exo, ATAC-seq and RNA-seq data

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    Transcription factor binding to DNA is a central mechanism regulating gene expression. Thus, thorough characterization of this process is essential for understanding cellular biology in both health and disease. We combined data from three sequencing-based methods to unravel the DNA binding function of the novel ZNF414 protein in cells representing two tumor types. ChIP-exo served to map protein binding sites, ATAC-seq allowed identification of open chromatin, and RNA-seq examined the transcriptome. We show that ZNF414 is a DNAbinding protein that both induces and represses gene expression. This transcriptional response has an impact on cellular processes related to proliferation and other malignancy-associated functions, such as cell migration and DNA repair. Approximately 20% of the differentially expressed genes harbored ZNF414 binding sites in their promoters in accessible chromatin, likely representing direct targets of ZNF414. De novo motif discovery revealed several putative ZNF414 binding sequences, one of which was validated using EMSA. In conclusion, this study illustrates a highly efficient integrative approach for the characterization of the DNA binding and transcriptional activity of transcription factors.Peer reviewe
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