2,202 research outputs found

    Biogas from manure – a new technology to close the nutrient and energy circuit on-farm

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    The Biodynamic Research Institute in Järna developed a two-phase on-farm biogas plant. The plant digests manure of dairy cattle and organic residues originating from the farm and the surrounding food processing units containing 17.7-19.6 % total solids. A new technology for continuously filling and discharging the hydrolysis reactor was developed and implemented. The output of the hydrolysis reactor is separated into a solid and liquid fraction. The solid fraction is composted. The liquid fraction is further digested in a methane reactor and the effluent used as liquid fertiliser. Initial results show that anaerobic digestion followed by aerobic composting of the solid fraction improves the nutrient balance of the farm compared to mere aerobic composting. Composted solid fraction and effluent together contain about 70.8 % of total input nitrogen and 93.3 % of input NH4. The manure that was merely aerobic digested contained about 51.3 % of total input nitrogen and 3.9 % of input NH4. Additionally anaerobic digestion improves the energy balance of the farm producing up to 269 l biogas kg-1 volatile solids or 1.7 kWh heat kg-1 volatile solids

    Baltic Ecological Recycling Agriculture and Society (BERAS project) - a case of Juva milk system

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    The aim of the study was to determine the potential, impact and prerequisites of localization and enhanced recycling in a rural food system, illustrated by the case of Juva milk. An interdisciplinary scenario based on the increase of local, organic milk to 50 % of milk comsumption was created and the sustainability was compared, on the basis of the statistics and data collected from the actors, with the present milk system

    Leeway for the loyal: a model of employee discretion

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    This article examines the factors underlying task discretion from an economist's perspective. It argues that the key axis for understanding discretion is the trade-off between the positive effects of discretion on potential output per employee and the negative effects of greater leeway on work effort. In empirical analysis using matched employer-employee data, it is shown that discretion is strongly affected by the level of employee commitment. In addition, discretion is generally greater in high-skilled jobs, although not without exceptions, and lower where employees are under-skilled. Homeworking and flexitime policies raise employee discretion. The impact of teamworking is mixed. In about half of cases team members do not jointly decide about work matters, and the net effect of teams on task discretion in these cases is negative. In other cases, where team members do decide matters jointly, the impact is found to be neutral according to employees' perceptions, or positive according to managers' perceptions. There are also significant and substantial unobserved establishment-level factors which affect task discretion

    The chaotic behavior of the black hole system GRS 1915+105

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    A modified non-linear time series analysis technique, which computes the correlation dimension D2D_2, is used to analyze the X-ray light curves of the black hole system GRS 1915+105 in all twelve temporal classes. For four of these temporal classes D2D_2 saturates to 45\approx 4-5 which indicates that the underlying dynamical mechanism is a low dimensional chaotic system. Of the other eight classes, three show stochastic behavior while five show deviation from randomness. The light curves for four classes which depict chaotic behavior have the smallest ratio of the expected Poisson noise to the variability (<0.05 < 0.05) while those for the three classes which depict stochastic behavior is the highest (>0.2 > 0.2). This suggests that the temporal behavior of the black hole system is governed by a low dimensional chaotic system, whose nature is detectable only when the Poisson fluctuations are much smaller than the variability.Comment: Accepted for publication in Astrophysical Journa

    Self-reported sleep disturbance and incidence of dementia in ageing men

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    Background Sleep disturbance is suggested to contribute to the development of dementia. However, prospective longitudinal data from middle-aged populations are scarce. Methods We investigated a population-based sample of 2386 men aged 42-62 years at baseline during 1984-1989. Participants having a history of mental illnesses, psychiatric medication, Parkinson's disease or dementia within 2 years after baseline (n=296) were excluded. Difficulty falling asleep or maintaining sleep, sleep duration and daytime tiredness were enquired. Dementia diagnoses (n=287) between 1984 and 2014 were obtained through linkage with hospital discharge, national death and special reimbursement registers. Cox proportional hazards analyses were performed for all dementias, and separately for Alzheimer's disease (n=234) and other phenotypes (n=53). Additional analyses were performed on a subsample of an apolipoprotein E (APOE) genotype-tested population (n=1199). Results The risk ratio for dementia was 1.58 (95% CI 1.10 to 2.27) in men with frequent sleep disturbance after adjustments for age, examination year, elevated depressive symptoms, physical activity, alcohol consumption, cumulative smoking history, systolic blood pressure, body mass index, low-density lipoprotein and high-density lipoprotein cholesterol, high-sensitivity C reactive protein, cardiovascular disease history, education years and living alone. Daytime tiredness and sleep duration were not associated with dementia in adjusted analysis. In the APOE subsample, both APOE epsilon 4 genotype and frequent sleep disturbance were associated with increased dementia risk, but in the interaction analysis they had no joint effect. Conclusions Self-reported frequent sleep disturbance in middle-aged men may relate to the development of dementia in later life. Having an APOE e4 genotype did not affect the relationship

    The association between bacterial infections and the risk of coronary heart disease in type 1 diabetes

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    Background Diabetes increases the risk of infections as well as coronary heart disease (CHD). Whether infections increase the risk of CHD and how this applies to individuals with diabetes is unclear. Objectives To investigate the association between bacterial infections and the risk of CHD in type 1 diabetes. Methods Individuals with type 1 diabetes (n = 3781) were recruited from the Finnish Diabetic Nephropathy Study (FinnDiane), a prospective follow-up study. CHD was defined as incident events: fatal or non-fatal myocardial infarction, coronary artery bypass surgery or percutaneous coronary intervention, identified through national hospital discharge register data. Infections were identified through national register data on all antibiotic purchases from outpatient care. Register data were available from 1.1.1995-31.12.2015. Bacterial lipopolysaccharide (LPS) activity was measured from serum samples at baseline. Data on traditional risk factors for CHD were collected during baseline and consecutive visits. Results Individuals with an incident CHD event (n = 370) had a higher mean number of antibiotic purchases per follow-up year compared to those without incident CHD (1.34 [95% CI: 1.16-1.52], versus 0.79 [0.76-0.82],P <0.001), as well as higher levels of LPS activity (0.64 [0.60-0.67], versus 0.58 EU mL(-1)[0.57-0.59],P <0.001). In multivariable-adjusted Cox proportional hazards models, the mean number of antibiotic purchases per follow-up year was an independent risk factor for incident CHD (HR 1.21, 95% CI: 1.14-1.29,P <0.0001). High LPS activity was a risk factor for incident CHD (HR 1.93 [1.34-2.78],P <0.001) after adjusting for static confounders. Conclusion Bacterial infections are associated with an increased risk of incident CHD in individuals with type 1 diabetes.Peer reviewe

    Rigidity of escaping dynamics for transcendental entire functions

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    We prove an analog of Boettcher's theorem for transcendental entire functions in the Eremenko-Lyubich class B. More precisely, let f and g be entire functions with bounded sets of singular values and suppose that f and g belong to the same parameter space (i.e., are *quasiconformally equivalent* in the sense of Eremenko and Lyubich). Then f and g are conjugate when restricted to the set of points which remain in some sufficiently small neighborhood of infinity under iteration. Furthermore, this conjugacy extends to a quasiconformal self-map of the plane. We also prove that this conjugacy is essentially unique. In particular, we show that an Eremenko-Lyubich class function f has no invariant line fields on its escaping set. Finally, we show that any two hyperbolic Eremenko-Lyubich class functions f and g which belong to the same parameter space are conjugate on their sets of escaping points.Comment: 28 pages; 2 figures. Final version (October 2008). Various modificiations were made, including the introduction of Proposition 3.6, which was not formally stated previously, and the inclusion of a new figure. No major changes otherwis

    The Polyakov action on the supertorus

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    A consistent method for obtaining a well-defined Polyakov action on the supertorus is presented. This method uses the covariantization of derivative operators and enables us to construct a Polyakov action which is globally defined.Comment: 15 pages LaTe
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