Search Results - (Author, Cooperation:J. W. White)

2016-03-12

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2014-09-06

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

*Climate Change ; Computer Simulation ; Freezing ; Greenland ; *Ice Cover ; Models, Theoretical ; Oxygen Isotopes/analysis ; *Temperature

2012-06-29

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Atmosphere/*chemistry ; *Geography ; Methane/*analysis ; Microbial Consortia/*physiology

2014-10-31

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Antarctic Regions ; Atmosphere/chemistry ; *Carbon Cycle ; Carbon Dioxide/analysis ; Greenhouse Effect ; Greenland ; History, Ancient ; Ice Cover ; Isotopes ; Methane/analysis ; Oceans and Seas ; Water/analysis/chemistry

2012-08-04

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Atmosphere/*chemistry ; Carbon/analysis ; Carbon Dioxide/*analysis/history ; *Carbon Sequestration ; Climate Change/*statistics & numerical data ; History, 20th Century ; History, 21st Century ; Human Activities ; Models, Theoretical ; Oceans and Seas ; Seawater/*chemistry ; Time Factors ; Uncertainty

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The inelastic neutron scattering from H2 in C24Cs(H2)x has been measured at momentum transfers of 8〈Q〈22 A(ring)−1 as a function of filling, 0.5〈x〈2.0, and temperature from 20 to 150 K. The observed scattering approaches the limiting behavior predicted by the Impulse Approximation (IA) for molecular hydrogen for Q's greater than 15 A(ring)−1 and is insensitive to the filling factor and temperature up to kT/M≈0.1, where M is the enthalpy of hydrogen sorption. The results are analyzed using a model for the IA scattering from molecular hydrogen which takes into account the excitation of rotational transitions and the presence of a local orientational potential at the hydrogen adsorption sites. The average translational kinetic energy per molecule, which is determined by the effective local potential for the molecule, can be extracted from the measured scattering. For a powder sample, such as used in this measurement, determination of the kinetic energy requires independent knowledge of the orientational potential of the H2 molecules. Using the orientational potential inferred from previous tunneling measurements we extract an average translation kinetic energy of 320 K for the H2 molecule in the intercalate.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Design features of a proposed high-resolution, high-speed powder diffractometer for operation at a synchrotron source are described. A key feature of the design is the use of imaging plates to record an almost complete range of data including both the high-angle and the small-angle scattering regime. The x-ray optics involve the use of a condensing-collimating channel-cut monochromator (CCCC) to achieve narrow parallel beams with cross sections of the order of 50 μm in the plane of diffraction, so that geometrical aberrations are very low and the beam cross section is well matched to the spatial resolution of the imaging plate detector. Angular resolution in 2θ of the diffractometer is easily variable, and designed to range from 0.01° upwards. Optional translation of the detector perpendicular to the incident-beam direction makes it possible to obtain time-resolved data. Applications of the instrument include high-resolution powder data collection for Rietveld analysis, studies of dynamic phenomena such as chemical reactions and phase transformations, particle-size determination, texture analysis, residual-stress measurements, single-crystal studies of the truncation-rod effect and surface scattering, microdiffraction, combined high-angle and small-angle scattering measurements, and studies of multilayer structures. As an illustration of the sort of results attainable with the proposed system, we present an oscillation photograph of the crystal-truncation rod effect for a Si wafer which was recorded at a synchrotron source using an imaging plate as the detector.

Electronic Resource

1600-0560

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The Lafora type of progressive myoclonus epilepsy is a rare and fatal familial disease characterized by seizures, myoclonus, and dementia. This diagnosis was confirmed in 2 patients by demonstrating the presence of intracytoplasmic polygkicosan bodies, or Lafora bodies, in the peripheral portion of the eccrinc sweat gland duct. Exclusive use of the periodic acid-Schifl stain is recommended for demonstrating these diagnostic inclusions. Electron microscopy reveals fine pale-staining filaments, line clark-slaining granules, and dark-rimmed vacuoles within these non-inembranc-bound inclusions. Skin biopsy is the preferred method of confirming the diagnosis of Lafora disease.

Electronic Resource

1600-0560

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Two patients with benign cytophagic histiocytic panniculitis are presented and compared with the one benign and ten fatal cases previously reported. Benign-appearing histiocytes which engulf blood cells, nuclear debris, and platelets are the most characteristic feature of the disease. This cytophagia tends to be massive in the subcutaneous tissue and involves extracutaneous organs only in the fatal cases. The course is chronic in the benign form. Patients with the fatal form tend to have fever, hepatosplenomegaly, serosal effusions, ecchymoses, peripheral adenopathy, and mucosal ulcers. Anemia, leukopenia, elevated liver enzyme levels, and coagulopathy are present in almost all and hypocalcemia in many patients with a fatal course. Cytophagic histiocytic panniculitis may represent a form of regional histiocytosis primarily involving subcutaneous tissue. It is midway in the spectrum of the cytophagic histiocytoses.

Electronic Resource

1750-3841

Blackwell Publishing Journal Backfiles 1879-2005

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Process Engineering, Biotechnology, Nutrition Technology

Reduced quality and availability of traditional tinned retail containers for pure maple sirup has prompted the appearance of plastic containers for this product. Tests which four sirups were stored 6 months in glass, metal and two types plastic containers at three temperatures showed that the sirups in both plastics darkened significantly more than in the other containers during the storage, and a significant interaction between temperature and container was shown. The possibility of a sirup falling to the next lower USDA grade during storage is pointed out.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Samples of collagen were excised from tail tendons of adult rats and a bundle of fibrils 0.2 mm in diameter mounted under tension sufficient to remove the characteristic banded appearance under the polarising microscope and produce alignment of the fibrils. The Brillouin spectra were recorded ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] AT a time when superlatives are routinely used to describe the mundane, it is difficult to express the importance of two papers in this issue which present results from the new GRIP ice core in central Greenland. The GRIP Project Members1 and Dansgaard et al.2 (pages 203 and ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] We report accumulation-rate data from the Greenland Ice Sheet Project II (GISP2) ice core, which is being drilled at 72.6á° N, 38.5á° W, at an elevation of 3,200 m. The core has reached a depth of 2,250 m, about 75% of the ice-sheet thickness. The parallel Greenland Icecore ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] On 1 July 1993 the US Greenland Ice-Sheet Project 2 completed a 5-yr ice-core drilling effort when bedrock was reached near the summit of the Greenland ice sheet (72.58& deg; N, 38.48& deg; W, 3,208 m above sea level, mean annual temperature -31 & deg;C). The 3,053.44-m-long, ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The Greenland Ice-Sheet Project 2 (GISP2) is coring the summit of the Greenland ice sheet (72.6° N, 38.5° W) to develop a continuous high-resolution record of climate related parameters going back at least 200,000 years. The electrical conductivity measurement (ECM) measures the ability of ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] The disintegration of the North American and Eurasian ice sheets lasted approximately from 15,000 to 8,000 yr BP. During this transition period, the well-known B011ing/Aller0d- Younger Dryas (B/A-YD) climate oscillation occurred, the last of a long series of similar events that characterized the ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] We employ a simplified version of the global carbon and 13C budgets developed by Tans et al.4, to explore changes in d(δ13C)/ d/, where t is time. The budget relies on the fact7 that the product of total carbon and its isotopic ratio (Cxδ13C) is a conservative quantity in the ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] There are three major difficulties in interpreting the isotope composition of tree ring cellulose. ( 1 ) Organic matter is isotopi-cally inhomogeneous4' . (2) Complex biological, biochemical and hydrological processes take place during the growth of a tree7'12'15. (3) Isotope variations in ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] A 10.2-m sediment core, previously studied for palaeoclimate using pollen analysis2'3 was collected from a raised Sphagnum bog near Estancia Harberton, on the Beagle Channel (54° 53' S, 67° 10'W) in southern South America. This is a cold, coastal site with an average temperature at present ...

Electronic Resource

1871-4528

seed storage ; desiccants ; drying vegetable seeds

Springer Online Journal Archives 1860-2000

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Summary Toasted polished rice with less than 1% moisture content was used as desiccant for potato seed stored in closed jars. To reduce the moisture content of about 20 g of true potato seed from 11.5% to 4–5%, 30 to 40 g of toasted rice is needed depending on how fast drying is desired. For most crops, 5% seed moisture content is considered by the International Board for Plant Genetic Resources as a safe level for storage. Toasted rice was also used with small lots of tomato, pepper, lettuce, turnip and soya bean seeds to dry them to a safe level for storage. Toasted grains of wheat, maize and soya bean were also used successfully as desiccants, but proved to have less drying capacity than rice.

Electronic Resource