1,810 research outputs found

    Economic analysis of field afforestation and forest clearance for cultivation in Finland

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    Rational land use decisions of private landowners are analysed in the framework of Common Agricultural Policy and other public support schemes effective in Finland in 2003. Net present values are computed for a marginal hectare of a typical Finnish farm. Three alternative land uses are considered: traditional cultivation of oats (Avena sativa L.), cultivation of reed canary grass (Phalaris Arundinacea L.) for energy production, and production of Norway spruce (Picea abies [L.] Karst.) timber. Both arable land and forested land are considered as initial states. Experimental data from 38 afforested stands and distance-independent individual-tree stand growth model are used for computing discounted net returns from forestry. Statistics on market prices, average yields, prices and costs are used for obtaining estimates of land value under agricultural and energy production. Cultivation of energy grass gives clearly the highest economic outcome for arable land, but it has limited demand only in the neighbourhood of thermal power stations. Maintaining arable lands under traditional food production gives higher land value than afforestation. Without an option for agricultural use, public support makes afforestation investments profitable even for the least successfully established forest stands. However, possibilities to sell or to rent out retain arable lands under agricultural production, and explain poor success of the latest afforestation programme. Clearing additional forestland for agricultural production turns rational if clearing of the site is inexpensive, relative value growth of the existing timber stock is low, and future prospects of agricultural production are dependent on scale advantages.Common Agricultural Policy, energy grass, incentives, land use, Resource /Energy Economics and Policy,

    A new dimension to Turing patterns

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    It is well known that simple reaction-diffusion systems can display very rich pattern formation behavior. Here we have studied two examples of such systems in three dimensions. First we investigate the morphology and stability of a generic Turing system in three dimensions and then the well-known Gray-Scott model. In the latter case, we added a small number of morphogen sources in the system in order to study its robustness and the formation of connections between the sources. Our results raise the question of whether Turing patterning can produce an inductive signaling mechanism for neuronal growth.Comment: Movies available here at http://www.lce.hut.fi/research/polymer/turing.shtm

    Derivation and evaluation of a new extinction coefficient for use with the n-HUT snow emission model

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    In this study, snow slab data collected from the Arctic Snow Microstructure Experiment were used in conjunction with a six-directional flux coefficient model to calculate individual slab absorption and scattering coefficients. These coefficients formed the basis for a new semiempirical extinction coefficient model, using both frequency and optical diameter as input parameters, along with the complex dielectric constant of snow. Radiometric observations, at 18.7, 21.0, and 36.5 GHz at both horizontal polarization (H-Pol) and vertical polarization (V-Pol), and snowpit data collected as part of the Sodankylä Radiometer Experiment were used to compare and contrast the simulated brightness temperatures produced by the multi-layer Helsinki University of Technology snow emission model, utilizing both the original empirical model and the new semiempirical extinction coefficient model described here. The results show that the V-Pol RMSE and bias values decreased when using the semiempirical extinction coefficient; however, the H-Pol RMSE and bias values increased on two of the lower microwave bands tested. The unbiased RMSE was shown to decrease across all frequencies and polarizations when using the semiempirical extinction coefficient

    Olfactory and gustatory functions after free flap reconstruction and radiotherapy for oral and pharyngeal cancer : a prospective follow-up study

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    The senses of smell and taste can be adversely affected by both tumour- and treatment-related factors amongst head and neck cancer patients. The consequences may negatively impact nutritional status as well as quality of life in this patient population. This prospective longitudinal follow-up study is consisted of 44 patients treated for oral cavity, oropharyngeal or hypopharyngeal cancer with tumour resection and microvascular free tissue transfer reconstruction at the Helsinki University Hospital, Helsinki, Finland. Thirty-nine (89%) of them also received radiotherapy. The senses of smell (odour detection, identification and threshold test) and taste (electrogustometry) and quality of life (UW-QOL) were evaluated preoperatively, and at 6 weeks, 3 months, 6 months and 12 months, postoperatively. There were higher scores in the odour detection values in the 6-week and 3-month tests compared with preoperative values for the tumour side. Other detection scores did not differ statistically from the preoperative values neither in the tumour nor the contralateral side. However, in the odour identification test, all posttreatment values were statistically significantly higher than pretreatment ones. In the olfactory threshold test, no statistically significant differences were found between pre- and posttreatment values. Electrogustometry values for the taste on the tumour side were statistically significantly impaired at 6 weeks (p <0.05) and at 3 months (p <0.01) compared with the pretreatment results. They were also impaired at 6 months and at 12 months, although the differences were not statistically significant. The quality of life was impaired after treatment in this patient series. However, the correlation between quality of life and sense of taste was found only at one time point (3 months) and only with contralateral side measurements. We conclude that in oral and pharyngeal cancer patients the postoperative taste problems are related to the impairment on the taste sensation in the tongue but not with the sense of smell. Moreover, the impairment in the quality of life is not clearly related to the impaired sense of taste.Peer reviewe

    Evidence for spared attention to faces in 7-month-old infants after prenatal exposure to antiepileptic drugs

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    Introduction: Prenatal antiepileptic drug (AED) exposure is associated with an increased risk of cognitive impairment and autism spectrum disorders detected mainly at the age of two to six years. We examined whether the developitiental aberrations associated with prenatal AED exposure-could be-detected already in infancy and whether effects on visual attention can be observed at this early age. Material and methods: We compared a prospective cohort of infants with in utero exposure to AED (n = 56) with infants without drug exposures (n = 62). The assessments performed at the age of seven months included standardized neurodevelopmental scores (Griffiths Mental Developmental Scale and Hammersmith Infant Neurological Examination) as well as a novel eye-tracking-based test for visual attention and orienting to faces. Background information included prospective collection of AED exposure data, pregnancy outcome, neuropsychological evaluation of the mothers, and information on maternal epilepsy type. Results: Carbamazepine, oxcarbazepine, and valproate, but not lamotrigine or levetiracetam, were associated with impaired early language abilities at the age of seven months. The general speed of visuospatial orienting or attentional bias for faces measured by eye-tracker-based tests did not differ between AED-exposed and control infants. Discussion: Our findings support the idea that prenatal AED exposure may impair verbal abilities, and this effect may be detected already in infancy. In contrast, the early development of attention to faces was spared after in utero AED exposure. (C) 2016 Elsevier Inc. All rights reserved.Peer reviewe

    Body image and eating behavior in young adults born preterm

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    Objective: Previous studies have suggested that people born preterm have increased rates of eating disorders (ED). However, a recent study suggested lower levels of ED-related symptoms in the extreme group of adults born preterm with very low birth weight (<1,500 g). We examined symptoms related to EDs in adults born early (<34 weeks of gestational age) or late (34 to <37 weeks of gestational age) preterm. Methods: We studied young adults (mean age 24.1 years) from two birth cohorts: ESTER (Northern Finland 1985–1989) and AYLS (Uusimaa, Finland, 1985–1986). Of the participants, 185 were born early preterm, 348 late preterm, and 637 were term-born controls (N = 1,170). They completed three subscales of the Eating Disorder Inventory (EDI)−2, including Drive for Thinness (DT), Body Dissatisfaction (BD), and Bulimia (B). Group differences were examined by linear regression. Results: Young women born early preterm scored 4.1 points (95% CI −8.0, −0.2, p =.04) lower in summed EDI subscale scores than women born at term, when adjusted for age and cohort. This difference was observed also in DT and BD but not for B subscales. The differences persisted after adjustments for current, pre- and neonatal characteristics. We did not observe differences in EDI scores among men or women born late preterm when compared to controls. Discussion: Women born early preterm have significantly fewer symptoms related to EDs in early adulthood when compared to their peers born at term, which may protect from developing an ED

    Triggering Collapse of the Presolar Dense Cloud Core and Injecting Short-Lived Radioisotopes with a Shock Wave. I. Varied Shock Speeds

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    The discovery of decay products of a short-lived radioisotope (SLRI) in the Allende meteorite led to the hypothesis that a supernova shock wave transported freshly synthesized SLRI to the presolar dense cloud core, triggered its self-gravitational collapse, and injected the SLRI into the core. Previous multidimensional numerical calculations of the shock-cloud collision process showed that this hypothesis is plausible when the shock wave and dense cloud core are assumed to remain isothermal at ~10 K, but not when compressional heating to ~1000 K is assumed. Our two-dimensional models (Boss et al. 2008) with the FLASH2.5 adaptive mesh refinement (AMR) hydrodynamics code have shown that a 20 km/sec shock front can simultaneously trigger collapse of a 1 solar mass core and inject shock wave material, provided that cooling by molecular species such as H2O, CO, and H2 is included. Here we present the results for similar calculations with shock speeds ranging from 1 km/sec to 100 km/sec. We find that shock speeds in the range from 5 km/sec to 70 km/sec are able to trigger the collapse of a 2.2 solar mass cloud while simultaneously injecting shock wave material: lower speed shocks do not achieve injection, while higher speed shocks do not trigger sustained collapse. The calculations continue to support the shock-wave trigger hypothesis for the formation of the solar system, though the injection efficiencies in the present models are lower than desired.Comment: 39 pages, 14 figures. in press, Ap

    Alien Registration- Leppanen, Julius (Saint George, Knox County)

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    https://digitalmaine.com/alien_docs/13290/thumbnail.jp
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