Boundedness from H^1 to L^1 of Riesz transforms on a Lie group of exponential growth

Let $G$ be the Lie group given by the semidirect product of $R^2$ and $R^+$ endowed with the Riemannian symmetric space structure. Let $X_0, X_1, X_2$ be a distinguished basis of left-invariant vector fields of the Lie algebra of $G$ and define the Laplacian $\Delta=-(X_0^2+X_1^2+X_2^2)$. In this paper we consider the first order Riesz transforms $R_i=X_i\Delta^{-1/2}$ and $S_i=\Delta^{-1/2}X_i$, for $i=0,1,2$. We prove that the operators $R_i$, but not the $S_i$, are bounded from the Hardy space $H^1$ to $L^1$. We also show that the second order Riesz transforms $T_{ij}=X_i\Delta^{-1}X_j$ are bounded from $H^1$ to $L^1$, while the Riesz transforms $S_{ij}=\Delta^{-1}X_iX_j$ and $R_{ij}=X_iX_j\Delta^{-1}$ are not.Comment: This paper will be published in the "Annales de l'Institut Fourier

Heat maximal function on a Lie group of exponential growth

Let G be the Lie group R^2\rtimes R^+ endowed with the Riemannian symmetric space structure. Let X_0, X_1, X_2 be a distinguished basis of left-invariant vector fields of the Lie algebra of G and define the Laplacian \Delta=-(X_0^2+X_1^2+X_2^2). In this paper, we show that the maximal function associated with the heat kernel of the Laplacian \Delta is bounded from the Hardy space H^1 to L^1. We also prove that the heat maximal function does not provide a maximal characterization of the Hardy space H^1.Comment: 18 page

On the Timing of Education

We propose a simple investment model which shows that, in the presence of fluctuations in and uncertainty about the opportunity cost of time, marginal individuals may choose to delay their education if the opportunity cost of time is temporarily high. Importantly, it is when the completion of the degree is uncertain, but likely enough that individuals will consider delaying their education. As a result, when returns to education are relatively low, education and timing of education will be sensitive to fluctuations in the opportunity cost of time. If return is high, delay is never optimal. These findings are supported by Swedish university enrolment patterns, and cross-country evidence on age of university freshmen.Timing of Education; Fluctuating Opportunity Costs

On the H^1-L^1 boundedness of operators

We prove that if q is in (1,\infty), Y is a Banach space and T is a linear operator defined on the space of finite linear combinations of (1,q)-atoms in R^n which is uniformly bounded on (1,q)-atoms, then T admits a unique continuous extension to a bounded linear operator from H^1(R^n) to Y. We show that the same is true if we replace (1,q)-atoms with continuous (1,\infty)-atoms. This is known to be false for (1,\infty)-atoms.Comment: This paper will appear in Proceedings of the American Mathematical Societ

Deadlines and Distractions

We analyze the effect of deadlines on timing of effort when agents are occasionaly distracted. We show that agents precautiously work early when completion of the task is uncertain, but rather likely. Agents who are rarely distracted will always postpone effort since the risk of not completing is small. As a result, increasing the probability of being distracted may even increase the likelihood of meeting the deadline. We further show that introducing the possibility of having the deadline extended may improve the total probability of completing the task without reducing the probability of completing within the originally announced deadline.Deadlines; Timing of Effort; Optimal Incentives

Den gröna staden från koncept till praktik – om hur urban grönstruktur kan bidra till en ekologiskt hållbar stadsutveckling

The establishment of green areas in urban environment for ecological sustainability is a strategy recognized in academics as well as in politics and governance. This thesis investigates how and to what extent various measures and interventions of increased urban green areas and their ecological benefits may contribute to ecological sustainability and improve urban life quality. In addition to a literature review of topic this thesis also contains an applied study of the new construction project “Södra Nyhamnen” in Malmö. The study shows that measures and interventions to increase urban green areas can contribute to locally enhanced biodiversity, possible better air quality, infiltration of storm water and retainment of storm water contaminations in soil instead of polluting of receiving waters. Shading, less heat radiation and wind protection, will also regulate the local climate. The study further shows that measures for urban green areas contributes to improvement of local urban environment, although it should primarily be described as environmental health improvement and only secondly as ecologically sustainable, as the measures consist of reducing or remediating measures with environmental health focus

A Spatially Explicit Decision Support System for Assessment of Tree Stump Harvest Using Biodiversity and Economic Criteria

Stump harvesting is predicted to increase with future increasing demands for renewable energy. This may affect deadwood affiliate biodiversity negatively, given that stumps constitute a large proportion of the coarse deadwood in young managed forests. Spatial decision support for evaluating the integrated effects on biodiversity and production of stump harvesting is needed. We developed a spatially explicit decision support system (called MapStump-DSS), for assessment of tree stump harvesting using biodiversity and economic criteria together with different scenarios for biodiversity conservation and bioenergy market prices. Two novel key aspects of the MAPStump-DSS is that it (1) merges and utilizes georeferenced stump-level data (e.g., tree species and diameter) directly from the harvester with stand data that are increasingly available to forest managers and (2) is flexible toward incorporating both quantitative and qualitative criteria based on emerging knowledge (here biodiversity criteria) or underlying societal drivers and end-user preferences. We tested the MAPStump-DSS on a 45 ha study forest, utilizing harvester data on characteristics and geographical positions for >26,000 stumps. The MAPStump-DSS produced relevant spatially explicit information on the biodiversity and economic values of individual stumps, where amounts of "conflict stumps" (with both high biodiversity and economical value) increased with bioenergy price levels and strengthened biodiversity conservation measures. The MAPStump-DSS can be applied in practice for any forest site, allowing the user to examine the spatial distribution of stumps and to obtain summaries for whole forest stands. Information depicted by the MAPStump-DSS includes amounts, characteristics, biodiversity values and costs of stumps in relation to different scenarios, which also allow the user to explore and optimize biodiversity and economy trade-offs prior to stump harvest

Social, health and rehabilitation sector educators’ competence in evidence-based practice: A cross-sectional study

Aim The purpose of the study was to identify and describe the characteristic profiles of evidence-based practice competence of educators in the social, health and rehabilitation sectors and to establish relevant background factors. Design This study was carried out as a descriptive cross-sectional study. Methods Data were collected from social, health and rehabilitation sector educators working in the 21 Finnish universities of applied sciences and seven vocational colleges (n = 422; N = 2,330). A self-assessment instrument measuring evidence-based practice competence was used. Competence profiles were formed using a K-cluster grouping analysis. Results Three distinct competence profiles were identified and delineated. Most educators feel that they can guide students' critical thinking and are able to seek and produce scientific knowledge. Evidence-based practice competence was explained by background factors such as year of graduation (for higher degree), level of education, job title, current employer and current field of work.publishedVersio

雑記（文化二年、家数、人別、馬数、寺数書上外）

There is an unmet need to reliably and non-invasively monitor disease progression in preclinical Huntington's disease (HD) models. As a marker of axonal damage, neurofilament light chain (NfL) has been suggested a marker for neurodegeneration. NfL concentrations in blood and CSF were recently shown to have prognostic value for clinical HD progression and brain atrophy. We therefore hypothesized that CSF and blood NfL concentrations could be useful preclinical HD markers, reflecting underlying pathology. To test our hypothesis we utilized the R6/2 mouse model of HD and measured NfL concentrations in CSF and serum using the ultrasensitive Single molecule array (Simoa) platform. In addition, we assessed HD mouse disease characteristics. We found robust increases of NfL in CSF and serum in R6/2 mice compared to wild-type littermates. CSF and serum concentrations of NfL were significantly correlated, suggesting similar marker potential of serum NfL. CSF and serum concentrations of NfL correlated with disease severity, as assessed by striatal volume and body weight loss. We here provide evidence that CSF and blood NfL concentrations can be used as accessible and reliable pre-clinical HD markers. This will be of potential use for monitoring HD mouse model disease progression and evaluating preclinical disease-modifying treatment response