Cloud‐penetrating C‐band synthetic aperture radar imagery acquired during two ERS‐1/2 tandem missions (April 1996 and October 1997) was used in mapping burnt areas in South Kalimantan, Indonesia, ...during the 1997 Southeast Asia forest fire episode. Vegetated areas were classified by their low interferometric coherence in both the 1996 and 1997 imagery while the burnt areas were delineated by their increased coherence in 1997. A total of 552 kha of land was found to be burnt scars out of the 3.6 Mha area surveyed. The results were validated using a multispectral SPOT image of the area acquired in September 1997.
In this paper, a fast leave-one-out (LOO) evaluation formula is introduced for least squares support vector machine (LS-SVM) classifiers. The computation cost can be reduced to approximately 1/N when ...compared to normal LOO procedure (N is the number of training samples). Inspired by its fast speed, we are able to use it to replace the original level 3 posterior probability approximation formula of the Bayesian framework for LS-SVM classifiers. The improved inference framework shows higher generalization performance and faster computation speed.
A leucine to alanine substitution (L9'A) was introduced in the M2 region of the mouse alpha 4 neuronal nicotinic acetylcholine receptor (nAChR) subunit. Expressed in Xenopus oocytes, alpha 4(L9'A) ...beta 2 nAChRs were greater than or equal to 30-fold more sensitive than wild type (WT) to both ACh and nicotine. We generated knock-in mice with the L9'A mutation and studied their cellular responses, seizure phenotype, and sleep-wake cycle. Seizure studies on alpha 4-mutated animals are relevant to epilepsy research because all known mutations linked to autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) occur in the M2 region of alpha 4or beta 2 subunits. Thalamic cultures and synaptosomes from L9'A mice were hypersensitive to nicotine-induced ion flux. L9'A mice were similar to 15-fold more sensitive to seizures elicited by nicotine injection than their WT littermates. Seizures in L9'A mice differed qualitatively from those in WT: L9'A seizures started earlier, were prevented by nicotine pretreatment, lacked EEG spike-wave discharges, and consisted of fast repetitive movements. Nicotine-induced seizures in L9'A mice were partial, whereas WT seizures were generalized. When L9'A homozygous mice received a 10 mg/kg nicotine injection, there was temporal and phenomenological separation of mutant and WT-like seizures: an initial seizure similar to 20 s after injection was clonic and showed no EEG changes. A second seizure began 3-4 min after injection, was tonic-clonic, and had EEG spike-wave activity. No spontaneous seizures were detected in L9'A mice during chronic video/EEG recordings, but their sleep-wake cycle was altered. Our findings show that hypersensitive alpha 4 super(*) nicotinic receptors in mice mediate changes in the sleep-wake cycle and nicotine-induced seizures resembling ADNFLE.
The development of non-viral gene therapy has been hampered by an inability to reproducibly manufacture and characterize delivery system components and final formulations. Formation of ...interpolyelectrolyte complexes as the basis of various gene delivery methods has been approached as the first step towards development of synthetic viruses. We have found that preparation of interpolyelectrolyte complexes from disperse reagents gives a more homogeneous gene delivery vehicle than other methods. Methods which increase homogeneity also result in higher transfection efficiency in vivo. Expression levels of human growth hormone and other reporter proteins in mice confirm the potential of parenteral non-viral gene delivery for some therapeutic applications. Serum is demonstrated to inhibit transfection efficiency in vivo. Our results suggest that further development of methods to manufacture homogeneous disperse non-viral delivery vehicles with stealth characteristics may enhance both the potency and reproducibility of gene transfer in vivo.
Objective
The ability of nonfluoroscopically guided radiography of the knee to assess joint space loss is an important issue in studies of progression and treatment of knee osteoarthritis (OA), given ...the practical limitations of protocols involving fluoroscopically guided radiography of the knee. We evaluated the ability of the nonfluoroscopically guided fixed‐flexion radiography protocol to detect knee joint space loss over 3 years.
Methods
We assessed the same‐day test–retest precision for measuring minimum joint space width (JSW), the sensitivity for detection of joint space loss using serial films obtained a median of 37 months (range 23–47 months) apart, and the relationship of joint space loss to radiographic and magnetic resonance imaging (MRI) measures of knee OA. Participants were men and women (ages 70–79 years) with knee pain who were participating in the Health, Aging, and Body Composition Study. We assessed baseline radiographic OA and measured JSW using a computerized algorithm. Serial knee MRIs obtained over the same interval were evaluated for cartilage lesions.
Results
A total of 153 knees were studied, 35% of which had radiographic OA at baseline. The mean ± SD joint space loss for all knees over 3 years was 0.24 ± 0.59 mm (P < 0.001 for change). In knees with OA at baseline, the mean ± SD joint space loss over 3 years was 0.43 ± 0.66 mm (P < 0.001), and in knees with joint space narrowing at baseline, joint space loss was 0.50 ± 0.67 mm (P < 0.001). Joint space loss and its standardized response mean increased with the severity of baseline joint space narrowing and with the presence of cartilage lesions at baseline and worsening during followup.
Conclusion
Radiography of the knee in the fixed‐flexion view provides a sensitive and valid measure of joint space loss in multiyear longitudinal studies of knee OA, without the use of fluoroscopy to aid knee positioning.
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