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Forest systems cover more than 4.1 x 10(9) hectares of the Earth's land area. Globally, forest vegetation and soils contain about 1146 petagrams of carbon, with approximately 37 percent of this carbon in low-latitude forests, 14 percent in mid-latitudes, and 49 percent at high latitudes. Over two-thirds of the carbon in forest ecosystems is contained in(More)
High-harmonic generation (HHG) traditionally combines ~100 near-infrared laser photons to generate bright, phase-matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here, we show that by guiding a mid-infrared femtosecond laser in a high-pressure gas, ultrahigh harmonics can be generated, up to orders greater than 5000,(More)
T1 and magnetization transfer at a field strength of 7 Tesla were used to discriminate between water accumulation and protein mobilization in tissue undergoing infarction. Twelve rats subjected to acute stroke via intralumenal suture occlusion of the middle cerebral artery, and 19 controls, were studied. In MRI studies to 6 hr post-ictus, serial data(More)
Water exchange across capillary walls couples intra- and extravascular (IV-EV) protons and their magnetization. A bolus i.v. injection of an extracellular MRI contrast agent (MRCA) causes a large increase in the spin-lattice relaxation rate, R1, of water protons in the plasma and blood cells within the capillaries and changes the effective relaxation rate(More)
On 25 February 1989, at a meeting of the British Society for the History of Mathematics, I heard the late Professor Philip Holgate deliver a lecture 'Independent functions. Probability and analysis in Poland between the Wars', the written version of which appears below. The editor has kindly asked me to write a brief introduction to this work, setting it in(More)
Silicone-gel-filled breast implants have been widely used for breast augmentation and reconstruction after mastectomy. The rate of implant rupture and its sequelae are not known. We review the frequency, causes, sequelae, and detection of implant rupture. Materials testing of removed implants provides evidence that as implants age in vivo, they weaken and(More)
A new haemagglutination assay for Vi antibodies was evaluated in searches for symptom-free carriers of Salmonella typhi associated with sporadic cases of typhoid fever. The assay differs from previous ones in that a purified (instead of crude) Vi antigen from Citrobacter was used to sensitise the red blood cells. In ten sporadic outbreaks of typhoid stool(More)
Eleven ambulatory EEG (A/EEG) cassette tapes were sent to 5 reviewers from different EEG laboratories in the U.K. Each tape included one attack recorded from a different patient. Attacks were chosen to include various possible EEG changes that can occur during attacks on A/EEG. Reviewers were asked to give details of EEG changes seen during attacks and to(More)