561 research outputs found

    Jaottomat polynomit

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    Tiivistelmä. Tässä kandidaattitutkielmassa käsittelen polynomien jaottomuutta. Määrittelen polynomien jaottomuuden sekä todistan Eukleideen algoritmin pohjalta, että jokainen polynomi voidaan yksikäsitteisesti jakaa jaottomiin tekijöihin. Lisäksi todistan, että kokonaislukukertoiminen polynomi on jaollinen kokonaislukujen renkaassa jos ja vain jos se on jaollinen rationaalilukujen renkaassa. Tämän jälkeen esittelen ja todistan erilaisia kriteerejä, joiden avulla erilaisia polynomeja voidaan osoittaa jaottomaksi, ja lisäksi havainnollistan näitä kriteereitä esimerkein. Ensimmäinen esitelty kriteeri on Eisensteinin kriteeri, jonka mukaan polynomi on jaoton, mikäli se täyttää seuraavat ehdot. Ensimmäinen ehto on, että sen kaikki kertoimet suurinta astetta olevan termin kerrointa lukuun ottamatta ovat jaollisia jollakin alkuluvulla. Toinen ehto on, että sen suurinta astetta olevan termin kerroin ei ole jaollinen kyseisellä alkuluvulla, ja kolmas ehto on, että vakiokerron ei ole jaollinen tämän kyseisen alkuluvun neliöllä. Toinen esitelty kriteeri on kriteeri, jonka mukaan polynomi joka koostuu vain ja ainoastaan neljännen asteen termistä jonka kerroin on 1, toisen asteen termistä jonka kerroin on jokin kokonaisluku, ja vakiotermistä joka on jonkin kokonaisluvun neliö, on jaollinen jokaisen alkuluvun jäännösluokkarenkaassa. Kolmanneksi esitellyn kriteerin mukaan polynomi on jaoton, mikäli se saavuttaa tarpeeksi pienen arvon vähintäänkin sen astetta vastaavalla määrällä sellaisia kokonaislukuja, jotka eivät ole sen juuria. Viimeisenä käsitellään sellaisia polynomeja, jotka koostuvat neljästä termistä siten, että korkeinta astetta olevat termin kerroin on 1, toiseksi ja kolmanneksi korkeinta astetta olevien termien kertoimet ovat joko 1 tai -1 riippumatta toisistaan, ja vakiotermi on joko 1 tai -1. Tätä muotoa olevia polynomeja koskevan kriteerin mukaan niiden jaollisuus riippuu yksinomaan siitä, onko niillä juuria, jotka ovat ykkösen juuria

    Demonstrating the feasibility of standardized application program interfaces that will allow mobile/portable terminals to receive services combining UMTS and DVB-T

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    Crucial to the commercial exploitation of any service combining UMTS and DVB-T is the availability of standardized API’s adapted to the hybrid UMTS and DVB-T network and to the technical limitations of mobile/portable terminals. This paper describes work carried out in the European Commission Framework Program 5 (FP5) project CONFLUENT to demonstrate the feasibility of such Application Program Interfaces (API’s) by enabling the reception of a Multimedia Home Platform (MHP) based application transmitted over DVB-T on five different terminals with parts of the service running on a mobile phone

    Comparing wood production and carbon sequestration after extreme thinnings in boreal Scots pine stands

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    Fennoscandian studies of thinning responses are usually limited to low thinning with moderate intensities. We studied here intermediate commercial thinning of different types (low, crown/normal, crown/strict, where respectively mostly intermediate and suppressed trees, mostly dominant and co-dominant trees, and only dominant trees were removed) and intensities (moderate and heavy) in Scots pine (Pinus sylvestris L.) dominated stands. We analysed their responses in terms of wood production and carbon balance. We investigated three stands in Southern and Middle Finland at the stage of second or third commercial thinning (age 34–50 years). We observed their development for fifteen years, and then we further simulated it with MOTTI stand simulator until final felling (scheduled either at age 65 or 80 years). We considered various variables of interest related to the thinning outputs, volume production after thinning, simulated final felling, and carbon balance. For all variables of interest, there were negligible differences across thinning types, and strong ones across thinning intensities. Thinning removals were significantly higher in heavy than moderate treatments, although only crown heavy thinnings had significantly higher sawlog output than low moderate. Volume growth post thinning during the 15-years observation was highest in unthinned plots, followed by moderate and then heavy treatments. For both total standing volume at simulated final fellings and carbon balance at any times, there was a similar descending trend from unthinned to moderate to heavy treatments. Concluding, the results suggest that crown/normal thinning could be applied with moderate intensity as alternative to low thinning, while heavy thinnings do not provide commercial benefits in Scots pine stands. Heavy intermediate thinnings in Scots pine stands provides lower total carbon accumulation during rotation, and early higher wood products (although not necessarily in terms of sawlogs) at the expense of later ones. Moderate thinning reached on site carbon neutrality after 5-years, while heavy thinning after 15 years

    Randomised controlled feasibility study of a school-based multi-level intervention to increase physical activity and decrease sedentary behaviour among vocational school students

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    BACKGROUND: No school-based physical activity (PA) interventions among older adolescents have demonstrated long-term effectiveness, and few of them so far have addressed sedentary behaviour (SB). Based on behavioural theories and evidence, we designed a multi-level intervention to increase PA and decrease SB among vocational school students. This study investigates feasibility and acceptability of two main intervention components and research procedures. We also examine uptake of behaviour change techniques (BCTs) by the participants. METHODS: Design was an outcome assessor blinded, cluster-randomised controlled trial. Four classes of students (matched pairs) were randomised into one intervention and one control arm. The intervention consisted of (1) a 6-h group-based intervention for students, (2) two 2-h training workshops to reduce their students' sitting in class for teachers, and (3) provision of light PA equipment in classrooms. At baseline (T1), mid-intervention (T2) at 3 weeks, post-intervention (T3) and 6 months after baseline (T4) we measured hypothesised psychosocial mediators and self-reported PA and sitting. Objective assessment of PA and SB (7-day accelerometry) was conducted at T1, T3 and T4. Body composition (bioimpedance) was measured at T1 and T4. Students and teachers in the intervention arm filled in acceptability questionnaires at T3. RESULTS: Recruitment rate was 64% (students) and 88.9% (teachers), and at T3, all post-intervention measurements were completed by 33 students (retention 76.7%) and 15 teachers (retention 93.8%). Acceptability ratings of sessions were high (students M = 6.29, scale 1-7), and data collection procedures were feasible. Intervention arm students reported increased use of BCTs, but uptake of some key BCTs was suboptimal. BCT use correlated highly with objective measures of PA. Based on both self-report and student evaluation, teachers in the intervention arm increased the use of sitting reduction strategies at post-intervention and T4 follow-up (p < .05). CONCLUSIONS: We detected willingness of the target groups to participate, good response rates to questionnaires, adequate retention, as well as acceptability of the trial protocol. Investigation of BCT use among students helped further enhance intervention procedures to promote BCT use. After making necessary modifications identified, intervention effectiveness can next be tested in a definitive trial. TRIAL REGISTRATION: ISRCTN34534846 . Registered 23 May 2014. Retrospectively registered.Background: No school-based physical activity (PA) interventions among older adolescents have demonstrated long-term effectiveness, and few of them so far have addressed sedentary behaviour (SB). Based on behavioural theories and evidence, we designed a multi-level intervention to increase PA and decrease SB among vocational school students. This study investigates feasibility and acceptability of two main intervention components and research procedures. We also examine uptake of behaviour change techniques (BCTs) by the participants. Methods: Design was an outcome assessor blinded, cluster-randomised controlled trial. Four classes of students (matched pairs) were randomised into one intervention and one control arm. The intervention consisted of (1) a 6-h group-based intervention for students, (2) two 2-h training workshops to reduce their students' sitting in class for teachers, and (3) provision of light PA equipment in classrooms. At baseline (T1), mid-intervention (T2) at 3 weeks, post-intervention (T3) and 6 months after baseline (T4) we measured hypothesised psychosocial mediators and self-reported PA and sitting. Objective assessment of PA and SB (7-day accelerometry) was conducted at T1, T3 and T4. Body composition (bioimpedance) was measured at T1 and T4. Students and teachers in the intervention arm filled in acceptability questionnaires at T3. Results: Recruitment rate was 64% (students) and 88.9% (teachers), and at T3, all post-intervention measurements were completed by 33 students (retention 76.7%) and 15 teachers (retention 93.8%). Acceptability ratings of sessions were high (students M = 6.29, scale 1-7), and data collection procedures were feasible. Intervention arm students reported increased use of BCTs, but uptake of some key BCTs was suboptimal. BCT use correlated highly with objective measures of PA. Based on both self-report and student evaluation, teachers in the intervention arm increased the use of sitting reduction strategies at post-intervention and T4 follow-up (p <.05). Conclusions: We detected willingness of the target groups to participate, good response rates to questionnaires, adequate retention, as well as acceptability of the trial protocol. Investigation of BCT use among students helped further enhance intervention procedures to promote BCT use. After making necessary modifications identified, intervention effectiveness can next be tested in a definitive trial.Peer reviewe

    Herramientas de simulación para el apoyo de toma de decisiones en la gestión forestal adaptativa en Europa

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    In forest management there is a tendency towards measuring less and simulating more. In this context the development of reliable, user friendly forest simulators has become economically relevant. The objective of this perspective paper is to highlight the recent trends in forest simulation and to identify the remaining challenges to make forest simulation a reliable tool for forest policy and management. Experiences with forest simulators for various purposes in different geographical contexts illustrate how the important challenges of forest decision support can be addressed through flexible customization for different end-user categories, offering spatially explicit approaches at the landscape scale, and integrating empirical and mechanistic models in hybrid and bayesian simulation approaches. Recent development trends in forest simulation for decision support are mainly related to the ever increasing calculation speed and capacity of computers, facilitating the development of robust tools with comfortable user interface and realistic functions and options. Another trend is the combination of simulation tools with optimization and choice algorithms fading away the difference between simulators and decision support systems. The remaining challenges are basically in the high expectations of stakeholders concerning the ability of simulators to predict a range of outcomes in terms of ecosystem services and sustainability indicators, as well as the quality of their outcome in terms of output credibility to stakeholders. Need for accepted and realistic model validation and verification methods preferably using empirical data is crucial in this matter.En la planificación de la gestión forestal existe la tendencia a medir menos y similar más. En este contexto, el desarrollo de simuladores forestales es económicamente relevante para el gestor. El objetivo de este artículo es el de discutir y enfatizar tendencias en el ámbito de la simulación forestal e identificar retos importantes para que la simulación forestal sea una herramienta fiable en el proceso decisorio de la planificación forestal y en el de desarrollo de políticas. Varios ejemplos de simuladores forestales existentes y que responden a objetivos y escalas geográficas distintas, ilustran como la capacidad analítica de los gestores puede mejorar sustancialmente para responder a los grandes retos en el proceso decisorio de la gestión forestal. El artículo presenta simuladores que responden a necesidades de diferentes usuarios y hacen frente a distintas cuestiones, utilizando distintos enfoques y herramientas; desde simuladores espacialmente explícitos basados en modelos empíricos que son integrados con herramientas de optimización, hasta simuladores mecanísticos o basados en enfoques híbridos y bayesianos. El desarrollo más reciente en simulación forestal esta sobretodo relacionado con el incremento de capacidad de cálculo de los computadores, lo que ha facilitado el desarrollo de herramienta robustas y visuales, fáciles de utilizar por los usuarios finales. Otra tendencia, importante es la combinación de herramientas de simulación con técnicas de optimización númerica, lo cual posibilita el desarrollo de los mas modernos sistemas de soporte a la decisión. Uno de los retos más importantes es el de colmar las altas expectativas de los principales agentes y centros decisores forestales en relación a la capacidad de los simuladores y sistemas de apoyo a la decisión para proporcionar información relevante en relación a los servicios ecosistémicos e indicadores de sostenibilidad. En este contexto, es necesaria la validación de los diferentes modelos que configuran los simuladores haciendo uso de información empírica disponible

    Randomised controlled feasibility study of a school-based multi-level intervention to increase physical activity and decrease sedentary behaviour among vocational school students

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    BACKGROUND: No school-based physical activity (PA) interventions among older adolescents have demonstrated long-term effectiveness, and few of them so far have addressed sedentary behaviour (SB). Based on behavioural theories and evidence, we designed a multi-level intervention to increase PA and decrease SB among vocational school students. This study investigates feasibility and acceptability of two main intervention components and research procedures. We also examine uptake of behaviour change techniques (BCTs) by the participants. METHODS: Design was an outcome assessor blinded, cluster-randomised controlled trial. Four classes of students (matched pairs) were randomised into one intervention and one control arm. The intervention consisted of (1) a 6-h group-based intervention for students, (2) two 2-h training workshops to reduce their students' sitting in class for teachers, and (3) provision of light PA equipment in classrooms. At baseline (T1), mid-intervention (T2) at 3 weeks, post-intervention (T3) and 6 months after baseline (T4) we measured hypothesised psychosocial mediators and self-reported PA and sitting. Objective assessment of PA and SB (7-day accelerometry) was conducted at T1, T3 and T4. Body composition (bioimpedance) was measured at T1 and T4. Students and teachers in the intervention arm filled in acceptability questionnaires at T3. RESULTS: Recruitment rate was 64% (students) and 88.9% (teachers), and at T3, all post-intervention measurements were completed by 33 students (retention 76.7%) and 15 teachers (retention 93.8%). Acceptability ratings of sessions were high (students M = 6.29, scale 1-7), and data collection procedures were feasible. Intervention arm students reported increased use of BCTs, but uptake of some key BCTs was suboptimal. BCT use correlated highly with objective measures of PA. Based on both self-report and student evaluation, teachers in the intervention arm increased the use of sitting reduction strategies at post-intervention and T4 follow-up (p < .05). CONCLUSIONS: We detected willingness of the target groups to participate, good response rates to questionnaires, adequate retention, as well as acceptability of the trial protocol. Investigation of BCT use among students helped further enhance intervention procedures to promote BCT use. After making necessary modifications identified, intervention effectiveness can next be tested in a definitive trial. TRIAL REGISTRATION: ISRCTN34534846 . Registered 23 May 2014. Retrospectively registered.Background: No school-based physical activity (PA) interventions among older adolescents have demonstrated long-term effectiveness, and few of them so far have addressed sedentary behaviour (SB). Based on behavioural theories and evidence, we designed a multi-level intervention to increase PA and decrease SB among vocational school students. This study investigates feasibility and acceptability of two main intervention components and research procedures. We also examine uptake of behaviour change techniques (BCTs) by the participants. Methods: Design was an outcome assessor blinded, cluster-randomised controlled trial. Four classes of students (matched pairs) were randomised into one intervention and one control arm. The intervention consisted of (1) a 6-h group-based intervention for students, (2) two 2-h training workshops to reduce their students' sitting in class for teachers, and (3) provision of light PA equipment in classrooms. At baseline (T1), mid-intervention (T2) at 3 weeks, post-intervention (T3) and 6 months after baseline (T4) we measured hypothesised psychosocial mediators and self-reported PA and sitting. Objective assessment of PA and SB (7-day accelerometry) was conducted at T1, T3 and T4. Body composition (bioimpedance) was measured at T1 and T4. Students and teachers in the intervention arm filled in acceptability questionnaires at T3. Results: Recruitment rate was 64% (students) and 88.9% (teachers), and at T3, all post-intervention measurements were completed by 33 students (retention 76.7%) and 15 teachers (retention 93.8%). Acceptability ratings of sessions were high (students M = 6.29, scale 1-7), and data collection procedures were feasible. Intervention arm students reported increased use of BCTs, but uptake of some key BCTs was suboptimal. BCT use correlated highly with objective measures of PA. Based on both self-report and student evaluation, teachers in the intervention arm increased the use of sitting reduction strategies at post-intervention and T4 follow-up (p <.05). Conclusions: We detected willingness of the target groups to participate, good response rates to questionnaires, adequate retention, as well as acceptability of the trial protocol. Investigation of BCT use among students helped further enhance intervention procedures to promote BCT use. After making necessary modifications identified, intervention effectiveness can next be tested in a definitive trial.Peer reviewe

    The role of beliefs, expectations and values in decision-making favoring climate change adaptation—implications for communications with European forest professionals

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    Beliefs, expectations and values are often assumed to drive decisions about climate change adaptation. We tested hypotheses based on this assumption using survey responses from 508 European forest professionals in ten countries. We used the survey results to identify communication needs and the decision strategies at play, and to develop guidelines on adequate communications about climate change adaptation. We observed polarization in the positive and negative values associated with climate change impacts accepted by survey respondents. We identified a mechanism creating the polarization that we call the 'blocked belief' effect. We found that polarized values did not correlate with decisions about climate change adaptation. Strong belief in the local impacts of climate change on the forest was, however, a prerequisite of decision-making favoring adaptation. Decision-making in favor of adaptation to climate change also correlated with net values of expected specific impacts on the forest and generally increased with the absolute value of these in the absence of 'tipping point' behavior. Tipping point behavior occurs when adaptation is not pursued in spite of the strongly negative or positive net value of expected climate change impacts. We observed negative and positive tipping point behavior, mainly in SW Europe and N-NE Europe, respectively. In addition we found that advice on effective adaptation may inhibit adaptation when the receiver is aware of effective adaptation measures unless it is balanced with information explaining how climate change leads to negative impacts. Forest professionals with weak expectations of impacts require communications on climate change and its impacts on forests before any advice on adaptation measures can be effective. We develop evidence-based guidelines on communications using a new methodology which includes Bayesian machine learning modeling of the equivalent of an expected utility function for the adaptation decision problem

    Antibodies Targeted to the Brain with Image-Guided Focused Ultrasound Reduces Amyloid-β Plaque Load in the TgCRND8 Mouse Model of Alzheimer's Disease

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    Immunotherapy for Alzheimer's disease (AD) relies on antibodies directed against toxic amyloid-beta peptide (Aβ), which circulate in the bloodstream and remove Aβ from the brain [1], [2]. In mouse models of AD, the administration of anti-Aβ antibodies directly into the brain, in comparison to the bloodstream, was shown to be more efficient at reducing Aβ plaque pathology [3], [4]. Therefore, delivering anti-Aβ antibodies to the brain of AD patients may also improve treatment efficiency. Transcranial focused ultrasound (FUS) is known to transiently-enhance the permeability of the blood-brain barrier (BBB) [5], allowing intravenously administered therapeutics to enter the brain [6]–[8]. Our goal was to establish that anti-Aβ antibodies delivered to the brain using magnetic resonance imaging-guided FUS (MRIgFUS) [9] can reduce plaque pathology. To test this, TgCRND8 mice [10] received intravenous injections of MRI and FUS contrast agents, as well as anti-Aβ antibody, BAM-10. MRIgFUS was then applied transcranially. Within minutes, the MRI contrast agent entered the brain, and BAM-10 was later found bound to Aβ plaques in targeted cortical areas. Four days post-treatment, Aβ pathology was significantly reduced in TgCRND8 mice. In conclusion, this is the first report to demonstrate that MRIgFUS delivery of anti-Aβ antibodies provides the combined advantages of using a low dose of antibody and rapidly reducing plaque pathology
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