13 research outputs found

    Interpretation and application of carbon isotope ratios in freshwater diatom silica

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    Carbon incorporated into diatom frustule walls is protected from degradation enabling analysis for carbon isotope composition (δ13Cdiatom). This presents potential for tracing carbon cycles via a single photosynthetic host with well-constrained ecophysiology. Improved understanding of environmental processes controlling carbon delivery and assimilation is essential to interpret changes in freshwater δ13Cdiatom. Here relationships between water chemistry and δ13Cdiatom from contemporary regional data sets are investigated. Modern diatom and water samples were collected from river catchments within England and lake sediments from across Europe. The data suggest dissolved, biogenically produced carbon supplied proportionately to catchment productivity was critical in the rivers and soft water lakes. However, dissolved carbon from calcareous geology overwhelmed the carbon signature in hard water catchments. Both results demonstrate carbon source characteristics were the most important control on δ13Cdiatom, with a greater impact than productivity. Application of these principles was made to a sediment record from Lake Tanganyika. δ13Cdiatom co-varied with δ13Cbulk through the last glacial and Holocene. This suggests carbon supply was again dominant and exceeded authigenic demand. This first systematic evaluation of contemporary δ13Cdiatom controls demonstrates that diatoms have the potential to supply a record of carbon cycling through lake catchments from sediment records over millennial timescales

    Fighting stochastic variability in a D-type flip-flop with transistor-level reconfiguration

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    In this study, the authors present a design optimisation case study of D-type flip-flop timing characteristics that are degraded as a result of intrinsic stochastic variability in a 25 nm technology process. What makes this work unique is that the design is mapped onto a multi-reconfigurable architecture, which is, like a field programmable gate array (FPGA), configurable at the gate level but can then be optimised using transistor level configuration options that are additionally built into the architecture. While a hardware VLSI prototype of this architecture is currently being fabricated, the results presented here are obtained from a virtual prototype implemented in SPICE using statistically enhanced 25 nm high performance metal gate MOSFET compact models from gold standard simulations for pre-fabrication verification. A D-type flip-flop is chosen as a benchmark in this study, and it is shown that timing characteristics that are degraded because of stochastic variability can be recovered and improved. This study highlights significant potential of the programmable analogue and digital array architecture to represent a next-generation FPGA architecture that can recover yield using post-fabrication transistor-level optimisation in addition to adjusting the operating point of mapped designs

    Clinical Relevance of Dissolution Testing in Quality by Design

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    Quality by design (QbD) has recently been introduced in pharmaceutical product development in a regulatory context and the process of implementing such concepts in the drug approval process is presently on-going. This has the potential to allow for a more flexible regulatory approach based on understanding and optimisation of how design of a product and its manufacturing process may affect product quality. Thus, adding restrictions to manufacturing beyond what can be motivated by clinical quality brings no benefits but only additional costs. This leads to a challenge for biopharmaceutical scientists to link clinical product performance to critical manufacturing attributes. In vitro dissolution testing is clearly a key tool for this purpose and the present bioequivalence guidelines and biopharmaceutical classification system (BCS) provides a platform for regulatory applications of in vitro dissolution as a marker for consistency in clinical outcomes. However, the application of these concepts might need to be further developed in the context of QbD to take advantage of the higher level of understanding that is implied and displayed in regulatory documentation utilising QbD concepts. Aspects that should be considered include identification of rate limiting steps in the absorption process that can be linked to pharmacokinetic variables and used for prediction of bioavailability variables, in vivo relevance of in vitro dissolution test conditions and performance/interpretation of specific bioavailability studies on critical formulation/process variables. This article will give some examples and suggestions how clinical relevance of dissolution testing can be achieved in the context of QbD derived from a specific case study for a BCS II compound

    Carbon inputs from Miscanthus displace older soil organic carbon without inducing priming

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    The carbon (C) dynamics of a bioenergy system are key to correctly defining its viability as a sustainable alternative to conventional fossil fuel energy sources. Recent studies have quantified the greenhouse gas mitigation potential of these bioenergy crops, often concluding that C sequestration in soils plays a primary role in offsetting emissions through energy generation. Miscanthus is a particularly promising bioenergy crop and research has shown that soil C stocks can increase by more than 2 t C ha−1 yr−1. In this study, we use a stable isotope (13C) technique to trace the inputs and outputs from soils below a commercial Miscanthus plantation in Lincolnshire, UK, over the first 7 years of growth after conversion from a conventional arable crop. Results suggest that an unchanging total topsoil (0–30 cm) C stock is caused by Miscanthus additions displacing older soil organic matter. Further, using a comparison between bare soil plots (no new Miscanthus inputs) and undisturbed Miscanthus controls, soil respiration was seen to be unaffected through priming by fresh inputs or rhizosphere. The temperature sensitivity of old soil C was also seen to be very similar with and without the presence of live root biomass. Total soil respiration from control plots was dominated by Miscanthus-derived emissions with autotrophic respiration alone accounting for ∼50 % of CO2. Although total soil C stocks did not change significantly over time, the Miscanthus-derived soil C accumulated at a rate of 860 kg C ha−1 yr−1 over the top 30 cm. Ultimately, the results from this study indicate that soil C stocks below Miscanthus plantations do not necessarily increase during the first 7 years

    Novel genetic loci underlying human intracranial volume identified through genome-wide association

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    Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five novel loci for intracranial volume and confirmed two known signals. Four of the loci are also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic=0.748), which indicated a similar genetic background and allowed for the identification of four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, Parkinson’s disease, and enriched near genes involved in growth pathways including PI3K–AKT signaling. These findings identify biological underpinnings of intracranial volume and provide genetic support for theories on brain reserve and brain overgrowth

    Climate change impacts on global agriculture

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    Based on predicted changes in the magnitude and distribution of global precipitation, temperature and river flow under the IPCC SRES A1B and A2 scenarios, this study assesses the potential impacts of climate change and CO2 fertilization on global agriculture. The analysis uses the new version of the GTAP-W model, which distinguishes between rainfed and irrigated agriculture and implements water as an explicit factor of production for irrigated agriculture. Future climate change is likely to modify regional water endowments and soil moisture. As a consequence, the distribution of harvested land will change, modifying production and international trade patterns. The results suggest that a partial analysis of the main factors through which climate change will affect agricultural productivity provide a false appreciation of the nature of changes likely to occur. Our results show that global food production, welfare and GDP fall in the two time periods and SRES scenarios. Higher food prices are expected. No matter which SRES scenario is preferred, we find that the expected losses in welfare are significant. These losses are slightly larger under the SRES A2 scenario for the 2020s and under the SRES A1B scenario for the 2050s. The results show that national welfare is influenced both by regional climate change and climate-induced changes in competitiveness

    Biochar suppresses N<sub>2</sub>O emissions while maintaining N availability in a sandy loam soil

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    Nitrous oxide (N2O) from agricultural soil is a significant source of greenhouse gas emissions. Biochar amendment can contribute to climate change mitigation by suppressing emissions of N2O from soil, although the mechanisms underlying this effect are poorly understood. We investigated the effect of biochar on soil N2O emissions and N cycling processes by quantifying soil N immobilisation, denitrification, nitrification and mineralisation rates using 15N pool dilution techniques and the FLUAZ numerical calculation model. We then examined whether biochar amendment affected N2O emissions and the availability and transformations of N in soils. Our results show that biochar suppressed cumulative soil N2O production by 91% in near-saturated, fertilised soils. Cumulative denitrification was reduced by 37%, which accounted for 85–95 % of soil N2O emissions. We also found that physical/chemical and biological ammonium (NH4+) immobilisation increased with biochar amendment but that nitrate (NO3−) immobilisation decreased. We concluded that this immobilisation was insignificant compared to total soil inorganic N content. In contrast, soil N mineralisation significantly increased by 269% and nitrification by 34% in biochar-amended soil. These findings demonstrate that biochar amendment did not limit inorganic N availability to nitrifiers and denitrifiers, therefore limitations in soil NH4+ and NO3− supply cannot explain the suppression of N2O emissions. These results support the concept that biochar application to soil could significantly mitigate agricultural N2O emissions through altering N transformations, and underpin efforts to develop climate-friendly agricultural management techniques

    PALVELUTUOTTEEN HINNOITTELUN KEHITTÄMINEN

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    Tämän opinnäytetyön aiheena on palvelutuotteen hinnoittelun kehittäminen. Tutkimuksen kohteena on Tili- ja isännöitsijätoimisto Ky. Tili- ja isännöitsijätoimisto Ky on Vaasassa toimiva tili- ja isännöintitoimisto, joka tarjoaa taloushallinto- ja isännöintipalveluita yrityksille. Tutkimuksen tavoitteena on kehittää Tili- ja isännöitsijätoimisto Ky:n isännöitsijän palvelutuotteiden hinnoittelua. Hinnoittelumenetelmäksi valittiin toimintoperusteinen hinnoittelu, jonka lähtökohtana on selvittää asiakaskohtaisia välillisiä kustannuksia. Kysymys oli suorite-kohtaisten kustannusten laskemisesta, eli toimintoperusteisesta prosessilaskennasta. Toimintoperusteinen prosessilaskenta tukee hinnoittelun päätöstä. Toiminto-analyysin jälkeen selvitettiin resurssien kohdistumista yrityksen eri toiminnoille. Aluksi selvitettiin yrityksen kustannusajuri, jonka perusteella kustannukset on kohdistettu eri toiminnoille. Seuraavaksi selvitettiin toimintoajurin avulla toimintoihin liittyvät yksikkökustannukset. Tuotteiden hinnoittelussa myyntihinnan on tarkoituksena sisältää kaikkien kustannusten lisäksi voittotavoite. Tutkimuksen teoriaosuuden keskeisiä asioita ovat toimintoperusteisen kustannuslaskennan, sekä hinnoittelun perusteiden esittely. Niiden avulla voidaan perustella hinnoittelupäätöstä tukeva toimintolaskenta. Opinnäytetyössä esitellään lisäksi kustannusperusteista hinnoittelua sekä isännöintiä ja tilitoimistoa yleisesti. Tutkimusmenetelmänä käytettiin kvalitatiivista eli laadullista tutkimusta. Tutkimuksen teoriaosuuteen käytettiin toimintolaskennan, taloushallinnon alan sekä hinnoittelun teoriaan liittyvää kirjallisuutta. Aineistonkeruussa havainnoitiin yrityksen tilinpäätöstä vuodelta 2016 ja yrityksen toimintaa liittyviä ohjelmia sekä tietokantoja. Lisäksi haastateltiin Tili- ja isännöitsijätoimisto Ky:n omistajaa ja työntekijöitä.This research was designed to develop the used pricing method for the case firm Tili- ja isännöitsijätoimisto Ky. The main area of this research focused on the main service products in property management. The case firm offers financial accounting and management services to house companies and other customer companies. Activity based costing was selected as the new pricing method in order to identify the customer-specific indirect costs. The aim of activity-based costing was to support pricing decisions for the case firm. In the implementation steps, activities must be identified first, and then the process continues with an activity analysis. Once the costs of activity and its drivers have been identified and its costs have been determined, then the costs of activity is allocated to the service product. In the allocation process, when the activity driver has been determined, the cost per unit can then be determined. Once the product cost per unit has been determined then the case firm considers the generated value of its service product, so the pricing of all the service product sales cover the fixed expenses with any remaining contribution margin providing profits. The theoretical study of this thesis introduced activity based costing and pricing to support activity based cost implementation and pricing decisions. In addition, it introduced cost based pricing and property management business and accounting firms in general. This research was implemented using the qualitative research method. The research material consists of related activity based costing, financial management, management accounting and pricing literature. The theoretical information was gathered from scientific research, academic books and some material was collect-ed from the Internet. The empirical data in this research was gathered by observing the case company’s financial statement from the year 2016 together with some business activities related programs and databases. In addition, was collected by interviewing the case company owner and the other employers of the company
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