Llif yr atmosffer drydanol dros begwn y gogledd: arsylwadau tomograffi radio a SuperDARN

The paper investigates the structure and behaviour of the nighttime ionised (electrified) atmosphere in the polar and auroral regions; the region where the aurora borealis occurs. Of particular interest are plasma structures on horizontal scales of hundreds of kilometres. The observations presented were made by the radiotomography experiment of the University of Wales, Aberystwyth, which has four satellite receiving systems in the high Arctic near the north pole, at Ny Ålesund and Longyearbyen on Svalbard, Bjørnøya (Bear Island) and Tromsø on mainland Norway. Comparisons of tomography images with observations of plasma flow by the international SuperDARN radar suggest that large density plasma produced on the dayside flows across the polar region and into the night sector. The results contribute to the interpretation of physical processes that couple the Earth's environment with space, and are also of interest to users of radio systems where the ionised atmosphere can degrade the propagation of the signals

Monochromatic Progressions in Random Colorings

Let N^{+}(k)= 2^{k/2} k^{3/2} f(k) and N^{-}(k)= 2^{k/2} k^{1/2} g(k) where 1=o(f(k)) and g(k)=o(1). We show that the probability of a random 2-coloring of {1,2,...,N^{+}(k)} containing a monochromatic k-term arithmetic progression approaches 1, and the probability of a random 2-coloring of {1,2,...,N^{-}(k)} containing a monochromatic k-term arithmetic progression approaches 0, for large k. This improves an upper bound due to Brown, who had established an analogous result for N^{+}(k)= 2^k log k f(k).Comment: 5 page

Organic Farming at ADAS PwllPeiran 1993 - 2001

Agriculture at Pwllpeiran has a long history. Pwllpeiran was eventually established as an Experimental Husbandry Farm in 1955. During the following forty years, work at the farm achieved substantial improvements in the quality and quantity of lamb and beef produced, but by the turn of the millennium the emphasis of agricultural policy was turning away from increased livestock production per se and towards the development of environmentally sensitive farming systems. The 1,118 ha Pwllpeiran Research Farm is now managed by ADAS Wales. The land is rented from the National Assembly for Wales and the Forestry Commission. All of the land is under a ‘whole farm’ Environmentally Sensitive Area agreement. The results from the Pwllpeiran unit underline the difficulties of organic farming in a severely disadvantaged upland area. The unit’s performance demonstrates the potential for production of organic lamb and beef but it also indicates some of the limitations on organic production. Organic farming theory and practice developed primarily in the lowlands and on mixed farms and these origins remain clearly evident in current standards for organic agriculture. Farming in the hills and uplands is, however, in many ways distinct. The lack of opportunity to grow arable crops, the difficulties of growing legumes such as clover and the shortages of farmyard manure, organic fertilisers and farm produced feed all represent particular challenges to the organic hill farm. At Pwllpeiran, production has been constrained by declining soil fertility which in turn has had an adverse effect on grass / clover production and thus on herbage availability and forage conservation. The system operated to date has not produced enough FYM to maintain soil nutrient levels in all of the organic pastures, a major constraint on the level of production. This leads to two important conclusions regarding organic farming in the uplands. The first is the importance of regular and systematic soil sampling to identify possible nutrient deficiencies. The second is the need for sector bodies to recognise that organic farming in severely disadvantaged high rainfall hill areas may require more regular input of permitted P and K fertilisers than lowland and mixed farms. Without such inputs production levels are likely to fall in the medium to long-term and more work needs to done on the best method of supplying these nutrients to the organic hill farm. At Pwllpeiran the decision was taken to accept a lower stocking rate on the organic unit, and to maintain financial performance by generating extra income from ESA agri environment payments and organic premiums. The unit’s experience demonstrates that combining organic farming with environmental conservation schemes on the mountain farm may add to the unit’s income, but environmental prescriptions will also place further limits on production. The balance of advantages to the organic hill farm offered by entry into an environmental management scheme needs to be weighed carefully. The future viability of the Pwllpeiran organic unit depends on maintaining farm income levels by optimising herbage and forage production and utilisation, and by controlling input costs, and producing quality beef and lamb. The impact of other factors like market prices, global trade and government policy will prove equally important. Control of these lies beyond the farm gate

National Curriculum Assessment and Public Examination Results in Wales: 2006

This document provides the audience with the 2006 National Curriculum results for Key Stages 1, 2 and 3, and results of GCSE/GNVQ and A/AS Level for Local Education Authorities and for Wales

'Dim Sôn am Dduw na Dyn': Ar Drywydd yr 'U Ogleddol' yng Nghanolbarth Cymru. (“No Mention of a Duw or a Dyn”: Investigating the ‘Northern U’ vowel in mid-Wales)

The high central vowel, or the ‘northern u’ as it is informally called, is well known to be a characteristic feature of northern Welsh. Generally in north Wales, a clear contrast is heard between pairs such as ‘tŷ’ / ‘ti’ and ‘sur’ / ‘sir’. Conversely, since this contrast is neutralised in the south, these words are homophones, and are always pronounced with the high front vowel ‘i’. The main aim of this study therefore is to analyse quantitatively the way in which this contrast between ‘northern u’ and ‘southern i’ is lost in parts of mid-Wales. Consequently, the results will show the complex patterns of variation that arise in one particular ‘transition zone’, namely the Tywyn district, and demonstrate how speakers’ use of the high central vowel in this area is conditioned to a considerable extent by specific linguistic factors. Finally, this article will postulate that the interchange between the high front and the high central vowels is also related to variation in the length of diphthongs, and the implications of this theory will be probed

Relationship of runoff, erosion and sediment yield to weather types in the Iberian Peninsula

Precipitation has been recognized as one of the main factors driving soil erosion and sediment yield (SY), and its spatial and temporal variability is recognized as one of themain reasons for spatial and temporal analyses of soil erosion variability. The weather types (WTs) approach classifies the continuumof atmospheric circulation into a small number of categories or types and has been proven a good indicator of the spatial and temporal variability of precipitation. Thus, themain objective of this study is to analyze the relationship betweenWTs, runoff, soil erosion (measured in plots), and sediment yield (measured in catchments) in different areas of the Iberian Peninsula (IP) with the aimof detecting spatial variations in these relationships. To this end, hydrological and sediment information covering the IP from several Spanish research teams has been combined, and related with daily WTs estimated by using the NMC/NCAR 40-Year Reanalysis Project. The results showthat, in general, a fewWTs (particularly westerly, southwesterly and cyclonic) provide the largest amounts of precipitation; and southwesterly, northwesterly and westerly WTs play an important role in runoff generation, erosion and sediment yield as they coincide with the wettest WTs. However, this study highlights the spatial variability of erosion and sediment yield in the IP according to WT, differentiating (1) areas under the influence of north and/or north-westerly flows (the north coast of Cantabria and inland central areas), (2) areas under the influence of westerly, southwesterly and cyclonic WTs (western and southwestern IP), (3) areas in which erosion and sediment yield are controlled by easterly flows (Mediterranean coastland), and (4) lastly, a transitional zone in the inland northeast Ebro catchment,wherewe detected a high variability in the effects ofWTs on erosion. Overall results suggest that the use of WTs derived fromobserved atmospheric pressure patterns could be a useful tool for inclusion in future projections of the spatial variability of erosion and sediment yield, as models capture pressure fields reliably

Validation of the face-name pairs task in major depression: impaired recall but not recognition

Major depression can be associated with neurocognitive deficits which are believed in part to be related to medial temporal lobe pathology. The purpose of this study was to investigate this impairment using a hippocampal-dependent neuropsychological task. The face-name pairs task was used to assess associative memory functioning in 19 patients with major depression. When compared to age-sex-and-education matched controls, patients with depression showed impaired learning, delayed cued-recall, and delayed free-recall. However, they also showed preserved recognition of the verbal and nonverbal components of this task. Results indicate that the face-name pairs task is sensitive to neurocognitive deficits in major depression.Thisresearchwasfundedbya4-yearHealthResearch Board grant