The test material (solid or liquid) is applied uniformly and topically to a three-dimensional human skin model, comprising at least a reconstructed epidermis with a functional stratum corneum. Two tissue replicates are used for each treatment (exposure time), and for controls. Corrosive materials are identified by their ability to produce a decrease in cell viability below defined threshold levels at specified exposure periods. The principle of the human skin model assay is based on the hypothesis that corrosive chemicals are able to penetrate the stratum corneum by diffusion or erosion, and are cytotoxic to the underlying cell layers.
The test material (150 μL for liquids or solid with 150 μL of deionised water added on the top) is applied for up to 24 hours to the epidermal surfaces of skin discs (three skin discs are used for each test and control substance) in a two-compartment test system in which the skin discs function as the separation between the compartments. The skin discs are taken from humanely killed rats aged 28-30 days. Corrosive materials are identified by their ability to produce a loss of normal stratum corneum integrity and barrier function, which is measured as a reduction in the TER below a threshold level (5kΩ for rat). A dye-binding step incorporated into the test procedure permits to determine if the increase in ionic permeability is due to physical destruction of the stratum corneum.
The test method utilizes an artificial membrane designed to respond to corrosive substances in a manner similar to animal skin in situ. The in vitro membrane barrier test method may be used to test solids, liquids (aqueous substances with a pH in the range of 4.5 to 8.5 often do not qualify for testing) and emulsions. The test described in this Test Guideline allows the identification of corrosive chemical substances and mixtures and allows the subcategorisation of corrosive substances as permitted in the GHS. This classification is based on the substance penetration time through the membrane barrier. The test system is composed of two components, a synthetic macromolecular bio-barrier and a Chemical Detection System (which one detect the test substance). An appropriate number of replicates is prepared for each test substance and its corresponding controls. The times of applying the test substance to the membrane barrier are recorded and staggered. The time (in minutes) elapsed between application of the test substance to the membrane barrier and barrier penetration is used to predict the corrosivity of the test substance.
The albino rabbit is the preferable laboratory animal. The substance to be tested is applied in a single dose to a small area of skin (approximately 6cm2) of an experimental animal; untreated skin areas of the test animal serve as the control. The exposure period is 4 hours. Residual test substance should then be removed. The dose is 0.5ml (liquid) or 0.5g (solid) applied to the test site. The method consists of two tests: the initial test and the confirmatory test (used only if a corrosive effect is not observed in the initial test). All animals should be examined for signs of erythema and oedema during 14 days. The dermal irritation scores should be evaluated in conjunction with the nature and severity of lesions, and their reversibility or lack of reversibility. When responses persist to the end of the 14-day observation period, the test substance should be considered an irritant.
The test material (solid or liquid) is applied uniformly and topically to a three-dimensional human skin model, comprising at least a reconstructed epidermis with a functional stratum corneum. Two tissue replicates are used for each treatment (exposure time), and for controls. Corrosive materials are identified by their ability to produce a decrease in cell viability below defined threshold levels at specified exposure periods. Coloured chemicals can also be tested by used of an HPLC procedure. The principle of the human skin model assay is based on the hypothesis that corrosive chemicals are able to penetrate the stratum corneum by diffusion or erosion, and are cytotoxic to the underlying cell layers.
This Test Guideline is intended primarily for use with guinea pig, but recently mouse models for assessing sensitisation potential have been developed. For the GPMT at least 10 animals in the treatment group and 5 in the control group are used. For the Buehler test, a minimum of 20 animals is used in the treatment group and at least 10 animals in the control group. The test animals are initially exposed to the test substance. Following a rest period, the induction period (10-14 days), during which an immune response may develop, then the animals are exposed to a challenge dose. The GPMT is made during approximately 23-25 days, the Buehler test, during approximately 30-32 days. The concentration of test substance used for each induction exposure should be well-tolerated systemically and should be the highest to cause mild-to moderate skin irritation, for the challenge exposure the highest nonirritant dose should be used. All skin reactions and any unusual findings should be observed and recorded (other procedures may be carried out to clarify doubtful reactions).
The test substance is administered daily, generally orally, to mated females (rats are preferred) from the time of implantation (GD 6) throughout lactation (PND 21). At least three dose levels and a concurrent control should be used and a total of 20 litters are recommended at each dose level. Dams are tested to assess effects in pregnant and lactating females and may also provide comparative information. Offspring are randomly selected from within litters for neurotoxicity evaluation. All dams and all offspring should be carefully observed at least once daily with respect to their health condition, including morbidity and mortality. The evaluation consists of observations to detect gross neurologic and behavioural abnormalities, and the evaluation of brain weights and neuropathology during postnatal development and adulthood. The report should include the body weight, the food/water consumption; the detailed clinical observations, the necropsy findings, a detailed description of all behavioural, the number of animals at the start and at the end of the study and the toxic response data by sex and dose level.
Data are provided for all OECD member countries (including area totals), and for Brazil, China, India, Indonesia, the Russian Federation and South Africa. For each indicator, there is a two-page spread: a text page includes a short introduction followed by a detailed definition of the indicator, comments on comparability of the data, an assessment of long-term trends related to the indicator and a list of references for further information on the indicator; the second page contains a table and a graph providing, at a glance, the key message conveyed by the data. Each indicator includes "StatLinks" which allow readers to download the corresponding data.
OECD Countries covered include Australia, Austria, Belgium, Canada, Chile,Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Japan, Korea, Luxembourg, Mexico, Netherlands, New Zealand, Poland, Portugal, Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, the United Kingdom, and the United States. Non-OECD countries covered include Brazil, China, India, Indonesia, Russia, and South Africa.
Topics covered include population and migration; production and productivity; household income, wealth and debt; globalisation, trade and foreign direct investment (FDI); prices, interest rates and exchange rates; energy and transportation; labour, employment and unemployment; science and technology including research and development (R&D) and the Information and Communications Technology (ICT) sector; environment including natural resoures, water,and air and climate; education resources and outcomes; government expenditures, debt, revenues, taxes, agricultural support and foreign aid; and health status, risk and resources.
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This book assembles information on the space economy from a wide range of official and non-official sources. Together these paint a richly detailed picture of the space industry, its downstream services activities, and its wider economic and social impacts. Who are the main space-faring nations? How large are revenues and how much employment is there in the sector? How much R&D goes on, and where? What is the value of spin-offs from space spending? Answers to these and other questions are provided in this second OECD statistical overview of the emerging space economy.
A dynamic link (StatLink) is provided for graphs, which directs the user to a web page where the corresponding data are available in Excel® format.
Key evaluation principles are set out, including the ‘Six Steps to Heaven’ approach. These principles are illustrated with examples of evaluations of national, regional and local programmes that can be explored further by the reader.
The publication focuses not only on the evaluation of individual policies and programmes, but also on peer review evaluations and assessment of the impact of SMEs and entrepreneurship of mainstream programmes that do not have business development as their principal aim. This book complements other existing guidelines, as it focusses particularly on problem situations and exceptions to the general rules.
The document looks at the state of science and technology in the OECD across four broad dimensions:
• Section A: Innovation and R&D.
• Section B: Human Resources in Science and Technology (HRST).
• Section C: Patents.
• Section D: Other areas (ICT, globalisation, industrial structure).
It is essential for long-term world prosperity that countries' commitment to trade and investment liberalisation be sustained. To be credible, that commitment must be rooted in and enjoy broad public support and understanding. This makes it all the more important to communicate what trade and investment liberalisation can and cannot do and be held responsible for.
Trade and investment liberalisation is not painless. It should not be viewed as a cure-all nor presented as an end in itself. It is, however, an essential component of any coherent set of policies aimed at helping societies adjust to - and take advantage of - technology-driven transformations whose pace and depth are unprecedented.
The stakes are high. This book examines the various channels through which open markets deliver considerable benefits to societies and their citizens; recalls the real pocket-book costs of protectionism; and addresses the full range of concerns that feature prominently in ongoing discussions over the effects of market liberalisation on employment, income distribution, environmental protection and national sovereignty.
A central message of this book is that liberalisation forms part of the solution to the concerns of citizens, rather than being their root cause. The book's comprehensive treatment of the ins and outs of trade and investment liberalisation should make an important contribution to the public debate. It is essential reading for public officials, business leaders and private citizens who wish to take an active part in it.
The report offers a comprehensive overview of the rapidly changing phenomenon of Open Educational Resources and the challenges it poses for higher education. It examines reasons for individuals and institutions to share resources for free, and looks at copyright issues, sustainability and business models as well as policy implications. It will be of particular interest to those involved in e-learning or strategic decision making within higher education, to researchers and to students of new technologies.