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The Next Generation Transit Survey (NGTS) is a new ground-based survey for transiting exoplanets. Our primary goal is to find the first statistically-significant sample of Neptunes and super-Earths that are bright enough for radial velocity confirmation. By measuring precise masses and radii we will constrain the bulk composition and internal structure of planets that span the transition between the gas giants and terrestrial planets. Our brightest exoplanets will also be suitable for atmospheric characterisation with large facilities such as the VLT, JWST and the E-ELT. NGTS construction began in June 2013, and the survey is due to commence in 2014.
The objective was to quantify the vitamin A equivalency of β-carotene in two diets using a dual-isotope dilution technique and the apparent β-carotene absorption as measured by the oral–faecal balance technique. Seventeen healthy adults with an ileostomy completed the 4-week diet-controlled, cross-over intervention study. Each subject followed both diets for 2 weeks: a diet containing vegetables low in β-carotene content with supplemental β-carotene in salad dressing oil (‘oil diet’; mean β-carotene intake 3·1 mg/d) and a diet containing vegetables and fruits high in β-carotene content (‘mixed diet’; mean β-carotene intake 7·6 mg/d). Daily each subject consumed a mean of 190 μg [13C10]β-carotene and 195 μg [13C10]retinyl palmitate in oil capsules. The vitamin A equivalency of β-carotene was calculated as the dose-corrected ratio of [13C5]retinol to [13C10]retinol in serum. Apparent absorption of β-carotene was determined with oral–faecal balance. Isotopic data quantified a vitamin A equivalency of [13C10]β-carotene in oil of 3·6:1 (95 % CI 2·8, 4·6) regardless of dietary matrices differences. The apparent absorption of (labelled and dietary) β-carotene from the ‘oil diet’ (30 %) was 1·9-fold higher than from the ‘mixed diet’ (16 %). This extrinsic labelling technique can measure precisely the vitamin A equivalency of β-carotene in oil capsules, but it does not represent the effect of different dietary matrices.
Recent studies have suggested that untreated coeliac disease is associated with lower total cholesterol than in the general population while the effect of treatment with a gluten-free diet on the cholesterol profile of clinically apparent coeliac disease is not known. We measured the cholesterol profile at diagnosis, and compared this with Health Survey for England figures, and again following 12 months treatment with a gluten-free diet in 100 consecutive adults with coeliac disease attending the Royal Hallamshire Hospital, Sheffield, UK. The mean total cholesterol was 4·84 (sd 1·2) mmol/l in adults (mean age 51 (sd 16) years) newly diagnosed with coeliac disease. At diagnosis of coeliac disease, men had 21 % lower and women had 9 % lower mean total cholesterol in comparison to the general population (difference in age-adjusted mean total cholesterol − 1·09 mmol/l (95 % CI − 0·97, − 1·21); − 0·46 mmol/l (95 % CI − 0·24, − 0·68), respectively). There was no change in mean total cholesterol following treatment. However, there was a small but statistically significant increase of 0·12 mmol/l (95 % CI 0·05, 0·18) in the mean HDL-cholesterol. Total cholesterol was lower at diagnosis in coeliac patients than in the general population and did not increase with 1 year of a gluten-free diet while HDL-cholesterol increased following treatment. Any increase in risk of IHD or stroke in people with coeliac disease is unlikely due to an adverse cholesterol profile either before diagnosis or after treatment with a gluten-free diet.
A total of 701 comets received names between July 2005 and June 2008. Comets observed only from the SOHO and STEREO missions, as well as further comets recognized from the long-defunct SOLWIND satellite, accounted for 520 of these names.
Data on the vitamin A equivalency of β-carotene in food are inconsistent. We quantified the vitamin A equivalency (μg) of β-carotene in two diets using the dual-isotope dilution technique and the oral–faecal balance technique. A diet-controlled, cross-over intervention study was conducted in twenty-four healthy adults. Each subject followed two diets for 3 weeks each: a diet containing vegetables low in β-carotene with supplemental β-carotene in salad dressing oil (‘oil diet’) and a diet containing vegetables and fruits high in β-carotene (‘mixed diet’). During all 6 weeks, each subject daily consumed a mean of 55 (sd 0·5) μg [13C10]β-carotene and 55 (sd 0·5) μg [13C10]retinyl palmitate in oil capsules. The vitamin A equivalency of β-carotene was calculated as the dose-corrected ratio of [13C5]retinol to [13C10]retinol in serum and from apparent absorption by oral–faecal balance. Isotopic data quantified a vitamin A equivalency of [13C10]β-carotene in oil of 3·4 μg (95 % CI 2·8, 3·9), thus the bio-efficacy of the β-carotene in oil was 28 % in the presence of both diets. However, data from oral–faecal balance estimated vitamin A equivalency as 6:1 μg (95 % CI 4, 7) for β-carotene in the ‘oil diet’. β-Carotene in the ‘oil diet’ had 2·9-fold higher vitamin A equivalency than β-carotene in the ‘mixed diet’. In conclusion, this extrinsic labelling technique cannot measure effects of mixed vegetables and fruits matrices, but can measure precisely the vitamin A equivalency of the β-carotene in oil capsules.
The chickenpox virus (varicella zoster virus; VZV) is known to cause large and small vessel central nervous system vasculopathies that may be associated with strokes in both adults and children. We present the case of a female aged 2 years 6 months who developed a chronic progressive small-vessel vasculopathy with radiological features of moyamoya disease as a manifestation of congenital varicella syndrome. Clinically, the condition was characterized by recurrent ischaemic strokes, which were brought under control using intravenous acyclovir. The case is unique in that it is the first report of congenital varicella syndrome to occur after a maternal herpes zoster infection. Furthermore, it is the first case of symptomatic VZV infection in a child to occur after a maternal infection occurring in the third trimester of pregnancy.
Astronomy knows no geographical borders - the sky is the same over all countries. However, while professional astronomers have long established bi- and multilateral collaborations, many of which take place under the auspices of the IAU, few similar schemes exist within astronomy education.
Now, following the establishment in 1995 of the European Association for Astronomy Education (EAAE), this situation is about to change on that continent. This new association offers an efficient platform for astronomy educators at various levels - in particular at the approx. 7000 secondary schools in this geographical area - to interact in all related matters, e.g. curricula, all kinds of teaching materials, student exchanges and other events. Together with the European Commission and some of the professional institutes, EAAE is now planning a major, international event in November 1996.
Production of embryos that are free of tough outer coats facilitates studies that are not possible with embryos surrounded by impenetrable envelopes. This report describes a new procedure for preventing formation of fertilisation membranes in the sea urchin (Lytechinus pictus) model. This procedure involves treating unfertilised eggs with the enzyme alpha-amylase, which cleaves alpha-1,4 glucosidic bonds in the vitelline layer. A major advantage of this method is that it is very well defined and completely controllable with alpha-amylase inhibitor. The results suggest that intact alpha-1,4 glucosidic bonds are essential for vitelline layer integrity required for formation of the fertilisation membrane. Eggs treated with alpha-amylase possessed the same surface lectin receptors as untreated eggs and, as shown by light and transmission electron microscopy, produced healthy, cleaving embryos that were free of fertilisation envelopes.
Stratigraphy provides a basic temporal and spatial framework for all studies of earth history. The foundations of stratigraphy were built in the 17th and 18th centuries through the efforts of Steno and Smith. Formalization of the principles of organic evolution followed closely in the mid-19th century with the publication of the Origin of Species. Although paleoecological observations span centuries, the establishment of paleoecology as a scientific discipline is a 20th century phenomenon. Initially, paleontology (paleobiology) was an integral part of stratigraphy and housed the subdisciplinary studies of evolution and paleoecology. Retention of a stratigraphic framework soon became difficult, perhaps due to the potential for circular reasoning in the evolutionary study of fossils. If the rock record was subdivided on the basis of fossils, how could the evolutionary relationships of these organisms be evaluated when they, or related forms, had been used to construct the temporal framework?
Lateral fluctuations of shoreline positions along shallow basinal margins often result in spatially and temporally overprinted (palimpsested) firmground or hardground surfaces (Frey and Basan, 1981). Recent palimpsested surfaces can teach us a great deal about the fossil record, particularly when we view them taphonomically. For the last few years we have been studying such surfaces along the seaward coast of St. Catherines Island, Georgia. In this paper we will first briefly discuss the modern salt marsh at St. Catherines Island, and its invertebrate inhabitants. This will form a basis for recognition and description of relict marsh surfaces. We will next describe the relict salt marsh surface that is currently being exhumed by coastal erosion and palimpsested by other invertebrate communities. Such palimpsested events also represent heterochronous community replacement–the disjunct temporal and (usually) spatial overprinting of an older community (or biogenic surface) by one (or more) younger communities. This interprets “replacement” as a passive, generally species non-interactive, phenomenon (contra Miller, 1986). Lastly, we will make some rather broad comparisons between the St. Catherines Island setting and what we interpret as analogous situations recorded in the Carboniferous strata of the Appalachian Basin.
Since the recovery in October 1982, an extensive, international programme to observe Comet Halley with ground-based instruments has been co-ordinated by the International Halley Watch (IHW), and a comprehensive archive is now in the final phases of preparation. The observations were carried out at more than 150 observatories and with all available methods. A special effort was made to support the space missions during the comet encounters in early March 1986. Whereas the spacecraft provided detailed in-situ measurements over a short time interval, ground-based observers have so far followed the development of the comet over a period of nearly six years, and a number of spectacular events near the nucleus and in the tail have been documented in great detail. These observations still continue. This article gives an overview of the most important results obtained from the ground and also mentions the prospects for further observations with large telescopes during the next years.
A popular hypothesis to explain the anomalous January returns of common stocks is based on the argument that there is considerable tax-loss selling by investors toward the end of the year. The purpose of this study is to test the tax-loss-selling hypothesis with data on Canadian stocks. Although the introduction of capital gains tax in Canada seems to have affected the behavior of stock returns, the findings do not support the proposition that taxinduced trading is the sole cause of the seasonality in stock returns in Canada.