Active fire detection using satellite thermal sensors usually involves thresholding the detected brightness temperature in several bands. Most frequently used features for fire detection are the ...brightness temperature in the 4-μm wavelength band (T 4 ) and the brightness temperature difference between 4- and 11-μm bands (/spl Delta/T=T 4 -T/sub 11/). The task of active fire detection is examined in the context of a stochastic model for target detection. The proposed fire detection method consists of applying a decorrelation transform in the (T 4 ,/spl Delta/T) space. Probability density functions for the fire and background pixels are then computed in the transformed variable space using simulated Moderate Resolution Imaging Spectroradiometer (MODIS) thermal data under different atmospheric humidity conditions and for cases of flaming and smoldering fires. The Pareto curve for each detection case is constructed. Optimal thresholds are derived by minimizing a cost function, which is a weighted sum of the omission and commission errors. The method has also been tested on a MODIS reference dataset validated using high-resolution SPOT images. The results show that the detection errors are comparable with the expected values, and the proposed method performs slightly better than the standard MODIS absolute detection method in terms of the lower cost function.
An extreme biomass-burning event occurred in Indonesia from September through October 2015 due to severe drought conditions, partially caused by a major El Nino event, thereby allowing for ...significant burning of peatland that had been previously drained. This event had the highest sustained aerosol optical depths (AOD) ever monitored by the global Aerosol Robotic Network (AERONET). The newly developed AERONET Version 3 algorithms retain high AOD at the longer wavelengths when associated with high Angstrom Exponents (AEs), which thereby allowed for measurements of AOD at 675 nanometers as high as approximately 7, the upper limit of Sun photometry. Measured AEs at the highest monitored AOD levels were subsequently utilized to estimate instantaneous values of AOD at 550 nanometers in the range of 11 to 13, well beyond the upper measurement limit. Additionally, retrievals of complex refractive indices, size distributions, and single scattering albedos (SSA) were obtained at much higher AOD levels than possible from almucantar scans due to the ability to perform retrievals at smaller solar zenith angles with new hybrid sky radiance scans. For retrievals made at the highest AOD levels the fine mode volume median radii were approximately 0.25 to 0.30 microns, which are very large particles for biomass burning. Very high SSA values (approximately 0.975 from 440 to 1020 nanometers) are consistent with the domination by smoldering combustion of peat burning. Estimates of the percentage peat contribution to total biomass burning aerosol based on retrieved SSA and laboratory measured peat SSA were approximately 80-85 percent, in excellent agreement with independent estimates.
We are developing a self-assembling non-viral in vivo gene delivery vehicle based on poly-
l-lysine and plasmid DNA. We have characterized poly-
l-lysines of different chain lengths for DNA ...condensation and strength of DNA binding. Poly-
l-lysine chains >20 residues bound DNA efficiently in physiological saline, while shorter chains did not. Attachment of asialoorosomucoid to PLL increased the PLL chain length required for efficient DNA binding in saline and for efficient DNA condensation. By electron microscopy, poly-
l-lysine/DNA polyplexes appeared as toroids 25–50 nm in diameter or rods 40–80 nm long; conjugation of asialoorosomucoid to the polylysine component increased the size of resulting polyplexes to 50–90 nm. In water, poly-
l-lysine and asialoorosomucoid–PLL polyplexes have effective diameters of 46 and 87.6 nm, respectively. Polyplexes containing only poly-
l-lysine and DNA aggregated in physiological saline at all charge ratios and aggregated at neutral charge ratios in water. Attachment of asialoorosomucoid lessened, but did not eliminate, the aggregation of PLL polyplexes, and did not result in efficient delivery of polyplexes to hepatocytes. Conjugation of polyethylene glycol to poly-
l-lysine sterically stabilized resulting polyplexes at neutral charge ratios by shielding the surfaces. For efficient in vivo gene delivery, polyplexes will need to be sterically stabilized to prevent aggregation and interaction with serum components.
Highlights • New method for objective assessment of anterior segment optical coherence tomography (AS-OCT) images using complex wavelet based local binary pattern features. It is a first work and ...up-to-date, there is no objective measurement of AS-OCT image quality. • An automatic approach is proposed to evaluate acquired OCT images with the intention of confirm the collection of high quality data. • An important contribution of this work is to propose an AS-OCT quality measurement function, which does not require any additional information (such as signal pixels and noise pixels) provided by the AS-OCT software for the AS-OCT scans. • Our proposed quality index has the ability of automatic objective and quantitative assessment of AS-OCT image quality and this quality index is similar an expert human observer.
A target nucleic acid sequence can be replicated (amplified) exponentially in vitro under isothermal conditions by using three enzymatic activities essential to retroviral replication: reverse ...transcriptase, RNase H, and a DNA-dependent RNA polymerase. By mimicking the retroviral strategy of RNA replication by means of cDNA intermediates, this reaction accumulates cDNA and RNA copies of the original target. Product accumulation is exponential with respect to time, indicating that newly synthesized cDNAs and RNAs function as templates for a continuous series of transcription and reverse transcription reactions. Ten million-fold amplification occurs after a 1- to 2-hr incubation, with an initial rate of amplification of 10-fold every 2.5 min. This self-sustained sequence replication system is useful for the detection and nucleotide sequence analysis of rare RNAs and DNAs. The analogy to aspects of retroviral replication is discussed.
A leucine to alanine substitution (L9′A) was introduced in the M2 region of the mouse α4 neuronal nicotinic acetylcholine receptor (nAChR) subunit. Expressed in
Xenopus
oocytes, α4(L9′A)β2 nAChRs ...were ≥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 α4-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 α4or β2 subunits. Thalamic cultures and synaptosomes from L9′A mice were hypersensitive to nicotine-induced ion flux. L9′A mice were ∼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 ∼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 α4
*
nicotinic receptors in mice mediate changes in the sleep-wake cycle and nicotine-induced seizures resembling ADNFLE.
PDF
