Nitric oxide synthase (NOS Types I-III) generate nitric oxide (NO), which in turn activates soluble guanylyl cyclase (GC-S). The distribution of this NO-mediated (nitrinergic) signal transduction pathway in the body is unclear. A polyclonal monospecific antibody to rat cerebellum NOS-I and a monoclonal antibody to rat lung GC-S were employed to localize the protein components of this pathway in different rat organs and tissues. We confirmed the localization of NOS-I in neurons of the central and peripheral nervous system, where NO may regulate cerebral blood flow and mediate long-term potentiation. GC-S was located in NOSnegative neurons, indicating that NO acts as an intercellular signal molecule or neurotransmitter. However, NOS-I was not confined to neurons but was widely distributed over IntroductionThe intracellular formation of nitric oxide (NO) has been extensively studied in various mammalian tissues. NO (1,2), or a labile intermediate that is able to release NO, is generated from a terminal guanidino nitrogen of L-arginine (3-5) by a family of NO synthases (NOS; EC 1.14.23). L-Citrulline is the byproduct of this metabolic pathway. NO is the first messenger molecule of a signal transduction pathway (Figure 1). Although other targets for NO Supported by research grants DK 30787 and H I . 28474 several non-neural cell types and tissues. These included glia cells, m a d densa of kidney, epithelial cells of lung, uterus, and stomach, and islets of Langerhans. Our findings suggest that NOS-I is the most widely distributed isoform of NOS and, in addition to its neural functions, regulates secretion and non-vascular smooth muscle function. With the exception of bone tissue, NADPH-diaphorase (NADPH-d) activity was generally co-localized with NOS-I immunoreactivity in both neural and non-neural cells, and is a suitable histochemical marker for NOS-I but not a selective neuronal marker. (J Histochem Cytochem 40:1439-1456, 1992) KEY WORDS: Cyclic GMP; Brain; Pancreas; Kidney; Stomach; Lung; Uterus; Bone; Epithelium; Endometrium. exist (6), its main mechanism of action involves binding to and activation of soluble guanylyl cyclase (GC-S; GTP pyrophosphatelyase (cyclizing), EC 4.6.1.2) (7), which then forms the second messenger molecule guanosine 3',5'-cyclic monophosphate (cGMP).NOS have been purified and characterized from brain (8-14), macrophages (15,16), and endothelial cells (17), and recently also from human cerebellum (18). Molecular cloning has provided clear evidence that brain (19) and macrophage (20) NOS are products of different genes. The relation between brain and endothelial NOS is unclear. Another polydonal antibody raised against rat brain NOS (21) was reported to bind to endothelial cell matrix, and the authors suggested that brain and endothelial NOS are highly homologous if not identical (22). Conversely, endothelial NOS was reported by our laboratory to differ from brain NOS with respect to molecular mass and subcellular location (17) and we proposed a classification of at least three types...

Many electronic watermarks for still images and video content are sensitive to geometric distortions. For example, simple rotation, scaling, and/or translation (RST) of an image can prevent blind detection of a public watermark. In this paper, we propose a watermarking algorithm that is robust to RST distortions. The watermark is embedded into a one-dimensional (1-D) signal obtained by taking the Fourier transform of the image, resampling the Fourier magnitudes into log-polar coordinates, and then summing a function of those magnitudes along the log-radius axis. Rotation of the image results in a cyclical shift of the extracted signal. Scaling of the image results in amplification of the extracted signal, and translation of the image has no effect on the extracted signal. We can therefore compensate for rotation with a simple search, and compensate for scaling by using the correlation coefficient as the detection measure. False positive results on a database of 10,000 images are reported. Robustness results on a database of 2000 images are described. It is shown that the watermark is robust to rotation, scale, and translation. In addition, we describe tests examining the watermarks resistance to cropping and JPEG compression.

We describe a new watermarking system based on the principles of informed coding and informed embedding. This system is capable of embedding 1380 bits of information in images with dimensions 240 × 368 pixels. Experiments on 2000 images indicate the watermarks are robust to significant valumetric distortions, including additive noise, low pass filtering, changes in contrast, and lossy compression.Our system encodes watermark messages with a modified trellis code in which a given message may be represented by a variety of different signals, with the embedded signal selected according to the cover image. The signal is embedded by an iterative method that seeks to ensure the message will not be confused with other messages, even after addition of noise. Fidelity is improved by the incorporation of perceptual shaping into the embedding process. We show that each of these three components improves performance substantially.

Electronic watermarking can be traced back as far as 1954. The last 10 years has seen considerable interest in digital watermarking, due, in large part, to concerns about illegal piracy of copyrighted content. In this paper, we consider the following questions: is the interest warranted? What are the commercial applications of the technology? What scientific progress has been made in the last 10 years? What are the most exciting areas for research? And where might the next 10 years take us? In our opinion, the interest in watermarking is appropriate. However, we expect that copyright applications will be overshadowed by applications such as broadcast monitoring, authentication, and tracking content distributed within corporations. We further see a variety of applications emerging that add value to media, such as annotation and linking content to the Web. These latter applications may turn out to be the most compelling. Considerable progress has been made toward enabling these applications—perceptual modelling, security threats and countermeasures, and the development of a bag of tricks for efficient implementations. Further progress is needed in methods for handling geometric and temporal distortions. We expect other exciting developments to arise from research in informed watermarking

The effects of traumatic brain injury (TBI) on brain chemistry and metabolism were examined in three groups of rats using high-resolution (1)H NMR metabolomics of brain tissue extracts and plasma. Brain injury in the TBI group (n = 6) was produced by lateral fluid percussion and regional changes in brain metabolites were analyzed at 1 h after injury in hippocampus, cortex and plasma and compared with changes in both a sham-surgery control group (n = 6) and an untreated control group (n = 6). Evidence was found of oxidative stress (e.g. decreases in ascorbate of 16.4% (p<0.01) and 29.7% (p<0.05) in cortex and hippocampus, respectively) in TBI rats versus the untreated control group, as well as excitotoxic damage (e.g. decreases in glutamate of 14.7% (p<0.05) and 12.3% (p<0.01) in the cortex and hippocampus, respectively), membrane disruption (e.g. decreases in the total level of phosphocholine and glycerophosphocholine of 23.0% (p<0.01) and 19.0% (p<0.01) in the cortex and hippocampus, respectively) and neuronal injury (e.g. decreases in N-acetylaspartate of 15.3% (p<0.01) and 9.7% (p>0.05) in the cortex and hippocampus, respectively). Significant changes in the overall pattern of NMR-observable metabolites using principal components analysis were also observed in TBI animals. Although TBI clearly had an effect on the metabolic profile found in brain tissue, no clear effects could be discerned in plasma samples. This was at least partly due to large variability in dominant glucose and lactate peaks in plasma. However, disruption of the blood-brain barrier and the subsequent movement of metabolites from brain into blood may have been relatively small and below the detection limits of our analytical procedures. Overall, these data indicate that TBI results in several significant changes in brain metabolism early after trauma and that a metabolomic approach based on (1)H NMR spectroscopy can provide a metabolic profile comprising several metabolite classes and allow for relative quantification of such changes within specific brain regions. The results also provide support for further development and application of metabolomic technologies for studying TBI and for the utilization of multivariate models for classifying the extent of trauma within an individual.