22,993 research outputs found
Lionel Billows (1909 – 2004): in memoriam
Lionel Billows, who died earlier this year at the age of ninety-four, was a pioneer of
what came to be known as ‘situational language teaching’, the mainstream approach
which preceded communicative language teaching in the British ELT tradition. He
was best-known for his book Techniques of Language Teaching (1961), whose
humanism and continuing interest value Maley (2001) has recently highlighted.
Billows’ most notable practical achievement was his work as Education Officer for
the British Council in South India between 1954 and 1960, when he conceived and
initially directed a ‘campaign’ for the wholesale retraining of 28,000 Primary School
teachers. This project has entered ELT mythology as the ‘Madras Snowball’, due to
an article by Billows’ successor which unaccountably fails to mention his contribution
(Smith 1962), but Billows himself disliked the term, preferring to call it instead the
‘MELT (Madras English Language Teaching) Campaign’
Discrete choice non-response
Missing values are endemic in the data sets available to econometricians. This paper suggests a unified likelihood-based approach to deal with several nonignorable missing data problems for discrete choice models. Our concern is when either the dependent variable is unobserved or situations when both dependent variable and covariates are missing for some sampling units. These cases are also considered when a supplementary random sample of observations on all covariates is available. A unified treatment of these various sampling structures is presented using a formulation of the nonresponse problems as a modification of choice-based sampling. Extensions appropriate for nonresponse are detailed of Imbens' (1992) effcient generalized method of moments (GMM) estimator for choice-based samples. Simulation evidence reveals very promising results for the various GMM estimators proposed in this paper.
Young men's ambivalence toward alcohol
There is widespread concern about the health and social consequences of excessive alcohol consumption among young men. Interventions to reduce alcohol-related harm will be affected by ambivalence toward alcohol, because ambivalent attitudes are worse predictors of behaviour than are homogeneous attitudes. It is therefore important to identify aspects of alcohol consumption about which young men are not ambivalent. In-depth interviews were conducted with a socioeconomically diverse sample of 31 men, aged 18–21 living in London, UK. Ambivalence toward alcohol was widespread. None of the drinkers who were interviewed had uncomplicated positive evaluations of drinking: all mentioned compelling reasons not to drink. Most motives for drinking were also identified as reasons for not drinking if consumption became excessive. However, three motives for not drinking were not also motives for drinking: violence, alcoholism, and cost. These findings should be considered during the design of interventions to reduce the health and social consequences of excessive alcohol consumption amongst young men
Planning for the semiconductor manufacturer of the future
Texas Instruments (TI) is currently contracted by the Air Force Wright Laboratory and the Defense Advanced Research Projects Agency (DARPA) to develop the next generation flexible semiconductor wafer fabrication system called Microelectronics Manufacturing Science & Technology (MMST). Several revolutionary concepts are being pioneered on MMST, including the following: new single-wafer rapid thermal processes, in-situ sensors, cluster equipment, and advanced Computer Integrated Manufacturing (CIM) software. The objective of the project is to develop a manufacturing system capable of achieving an order of magnitude improvement in almost all aspects of wafer fabrication. TI was awarded the contract in Oct., 1988, and will complete development with a fabrication facility demonstration in April, 1993. An important part of MMST is development of the CIM environment responsible for coordinating all parts of the system. The CIM architecture being developed is based on a distributed object oriented framework made of several cooperating subsystems. The software subsystems include the following: process control for dynamic control of factory processes; modular processing system for controlling the processing equipment; generic equipment model which provides an interface between processing equipment and the rest of the factory; specification system which maintains factory documents and product specifications; simulator for modelling the factory for analysis purposes; scheduler for scheduling work on the factory floor; and the planner for planning and monitoring of orders within the factory. This paper first outlines the division of responsibility between the planner, scheduler, and simulator subsystems. It then describes the approach to incremental planning and the way in which uncertainty is modelled within the plan representation. Finally, current status and initial results are described
The Potential Impact of the Great Recession on Future Retirement Incomes
Estimates the effects of job loss, slower wage growth, and withdrawals from retirement savings during the 2007-09 recession on retirement incomes at age 70, including decline in income by age group and number of those likely to live in poverty at 70
The effect of dust scattering on the timing properties of black holes
It has been known that sources with high absorption column density also have high dust column density along the line of sight. The differential delays caused by small angle scattering of X rays by dust may have important effects on the power spectra of Galactic black holes at low energies, and impact studies that use the relation between the rms amplitude of variability and energy to determine the origin of QPOs from these sources. We observed the high absorption column density (NH ˜1023 cm-2 ) GBH 1E1740.7-2942 for 20 ks simultaneously with XMM-Newton and RXTE. By comparing the power spectra from the events in the core of the point spread function (PSF) of XMM-Newton EPIC-PN (using imaging and excluding the scattering halo) and the RXTE data, we quantified the effects of small angle scattering on the timing properties of this source. The rms amplitude of variability in ˜2-6 keV band obtained from the XMM-Newton data is higher than that of the RXTE as expected from the a scattering halo contribution in the RXTE
Realistic Ionizing Fluxes for Young Stellar Populations from 0.05 to twice solar metallicity
We present a new grid of ionizing fluxes for O and Wolf-Rayet stars for use
with evolutionary synthesis codes and single star H II region analyses. A total
of 230 expanding, non-LTE, line-blanketed model atmospheres have been
calculated for five metallicities (0.05, 0.2, 0.4, 1 and 2 solar) using the
WM-basic code of Pauldrach et al. (2001) and the CMFGEN code of Hillier &
Miller (1998). The stellar wind parameters are scaled with metallicity for both
O and W-R stars. We incorporate the new models into Starburst99 (Leitherer et
al. 1999) and compare the ionizing outputs with Schaerer & Vacca (1998) and
Leitherer et al. (1999). The changes in the output ionizing fluxes are
dramatic, particularly below 228 A. We also find lower fluxes in the He I
continuum for Z > 0.4 solar and ages < 7 Myr because of the increased line
blanketing. We test the accuracy of the new models by constructing
photoionization models. We show that for the dwarf O star grid, He I 5876/H
beta decreases between Z = 1 and twice solar in a similar manner to
observations (e.g. Bresolin et al. 1999) due to the increased effect of line
blanketing. We therefore suggest that a lowering of the upper mass limit at
high abundances is not required to explain the observations. For the case of an
instantaneous burst, we plot the softness parameter "eta prime" against the
abundance indicator R_23. The new models are coincident with the data of
Bresolin et al. (1999), particularly during the W-R phase, unlike previous
models which over-predict the hardness of the ionizing radiation.Comment: 21 pages, 15 postscript colour figures, includes mn2e.cls. To be
published in MNRAS. Revised version containing modifications to Tables 1-
The geology of the Kirkmichael area, Ayrshire
This description is of the geology of 1:10 000 Sheet NS 30 NW (Kirkmichael) which lies within
1:50 000 Geological Sheet 14W Ayr (Scotland). The area is crossed by the north-easterly
trending Kerse Loch Fault (Figure 1) which separates mainly Siluro-Devonian strata to the
north-west from Carboniferous strata to the south-east. The Siluro-Devonian strata comprise
continental fluviatile sandstones and conglomerates, belonging to the Swanhaw Sandstone
Formation, which were intruded by a suite of basic to andesitic sills and dykes in early Devonian
times. The oldest Carboniferous rocks belong to the Inverclyde Group (Tournaisian to early
Visean), which includes the Kinnesswood, Ballagan and Clyde Sandstone formations. They are
not well exposed but represent a passage from semi-arid fluviatile sandstones through lagoonal
mudstones, sandstones and limestones back into semi-arid fluviatile sandstones. These are
unconformably succeeded by Visean deltaic deposits belonging to the Lawmuir Formation of the
Strathclyde Group. This formation is succeeded by the Upper Visean Lower Limestone
Formation and the Lower Namurian Limestone Coal Formation preserved within the core of the
major Dailly Syncline. The Limestone Coal Formation contains significant coal seams which
have been extensively mined. In Tertiary (Palaeocene) times minor intrusions of basaltic to
microgabbroic rock were intruded as part of the Mull Dyke Swarm. The age of some of the
mafic rocks is uncertain; they could be early Devonian to Palaeocene in age.
Quaternary deposits, laid down after the Late Devensian Glaciation, cover most of the
sedimentary rocks. The cover generally consists of lodgement till moulded below the ice into a
drumlin field. Remnants of the ice around Maybole downwasted and poorly sorted hummocky
glacial deposits accumulated. Glaciofluvial sand and gravel was deposited in patches near the
Water of Girvan and in a belt passing through Kirkmichael. A broad belt of alluvium was
deposited by the Water of Girvan and patches elsewhere occur between drumlins and hummocky
glacial deposits. Most of the soils in the area are loams. Heavy loams and peaty soils are found
locally in the alluvial areas near the Water of Girvan and the small lochans south-east of
Maybole. Minor areas of made ground are mapped, mostly around Maybole. Patches of worked
and worked and back-filled ground are even more limited
Pharmacogenetics of ophthalmic topical β-blockers
Glaucoma is the second leading cause of blindness worldwide. The primary glaucoma risk factor is elevated intraocular pressure. Topical β-blockers are affordable and widely used to lower intraocular pressure. Genetic variability has been postulated to contribute to interpersonal differences in efficacy and safety of topical β-blockers. This review summarizes clinically significant polymorphisms that have been identified in the β-adrenergic receptors (ADRB1, ADRB2 and ADRB3). The implications of polymorphisms in CYP2D6 are also discussed. Although the candidate-gene approach has facilitated significant progress in our understanding of the genetic basis of glaucoma treatment response, most drug responses involve a large number of genes, each containing multiple polymorphisms. Genome-wide association studies may yield a more comprehensive set of polymorphisms associated with glaucoma outcomes. An understanding of the genetic mechanisms associated with variability in individual responses to topical β-blockers may advance individualized treatment at a lower cost
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