In glaucoma, recent studies show that neural degeneration extends beyond the retinal ganglion cells to include target neurons in the lateral geniculate nucleus of the brain. The pathobiology of LGN ...degeneration in glaucoma is as yet unknown. We investigated whether peroxynitrite-mediated oxidative stress plays a role in glaucomatous degeneration of the LGN.
Nitrotyrosine (NT), a marker for peroxynitrite-mediated oxidative injury, was studied in right LGN sections from monkeys with experimental unilateral glaucoma in the right eye and from normal controls. Immunoreactivity for NT was analyzed using bright-field microscopy. The density of NT profiles localized in neural tissue was determined for LGN layers (2,3,5) connected to the glaucoma eye and LGN layers (1,4,6) connected to the non-glaucoma eye. Density was calculated for each LGN layer by dividing the number of NT profiles by the cross-sectional area of each LGN layer. Blood vessels in each LGN were examined for NT formation.
NT formation was detected in LGN layers of all monkeys with glaucoma. Quantitative analysis revealed that compared to controls, the density of NT profiles was increased in monkeys with glaucoma in LGN layers connected to glaucoma and non-glaucoma eyes. The mean density of NT profiles (±
sem) in neural tissue was significantly increased in glaucoma LGN layers compared to those of controls (2·30±0·56 vs. 0·29±0·12;
P=0·016). Nitrotyrosine was readily apparent in LGN blood vessel endothelium in glaucoma, and not detected in blood vessels of control LGNs.
The presence of NT in neural and vascular tissue of the glaucomatous LGN implicates peroxynitrite-mediated oxidative cell injury in the pathobiology of central neural degeneration in glaucoma.
We describe the MPEG2 4:2:2 Profile and present a study of its characteristics. The MPEG2 4:2:2 Profile provides a conformance point that addresses, among other applications, the needs of the ...professional studio and post-production environment, and that provides interoperability. The requirements of such an environment for compressed digital video together with a functional description of the 4:2:2 Profile are given. The 4:2:2 Profile provides a flexible compression solution that allows editability, supports a wide range of bit rates, and provides good to excellent quality in both an intra and interstudio environment. Our experiments show that the 4:2:2 Profile is very robust in a multigeneration environment, provides an efficient coding solution for transmission and storage, and provides transparency or near transparency in chroma keying operations. In addition, it compares favorably with existing digital compression standards, such as Motion-JPEG, and is superior to widely used analog technology.
A new adaptive technique is presented that is capable of nulling coherent, as well as incoherent, jammers while maintaining a fixed gain in the look direction. The technique depends on the use of new ...kind of correlation matrix and a subtractive preprocessor. It does not require any spatial smoothing. It requires 2M elements to null M-1 coherent jammers in the presence of noise. The matrix used in the technique is such that its unbiased estimate in the presence of noise can be obtained. This helps making the algorithm robust to noise in finding the desired weight vector to be used by the array.
Our objective was to investigate the accuracy of a new intravascular blood gas sensor, the Paratrend 7 (P7) (Biomedical Sensors Ltd, Pfizer Hospital Products Group, High Wycombe, England) in a ...porcine model.
A total of 12 sensors were inserted into 10 animals under total intravenous anesthesia. Changes in blood gas chemistry were produced over a wide range by manipulating the inspired oxygen and carbon dioxide concentrations and by adjustments in minute ventilation. Blood gas samples (BGA) were taken and analyzed during periods of stability; the results obtained were compared with the readings from the intravascular sensor.
A total of 292 blood gas samples were taken and analyzed for pHa, PaCO2, and Po2; the results were compared with the readings from the intravascular sensor. Correlation coefficients of r = 0.98 for PCO2 and r = 0.99 for PO2 were obtained. Analysis of bias and precision as mean +/- SD of the difference (P7 - BGA) gave the following results: pH bias = -0.03, precision = +/- 0.04; PCO2 bias = 0.65 mm Hg, precision = +/- 3.1 mm Hg; and PO2 bias = -6.50 mm Hg, precision = +/- 0.6 mm Hg. No problems with clot formation on the sensor were seen, and the sensors did not appear to show the "wall effect" seen with other systems.
The results obtained were well within the requirements for a clinically useful blood gas monitoring system.
This paper examines the perceived relationship between the presence and growth of the offshore oil industry in Louisiana and patterns of social disruption, particularly crime. Interview data were ...obtained from long-time residents in the coastal region of Louisiana, and a social constructionist perspective was used to frame the perceptions of these individuals (
N
=
94). Much previous research on the effects offshore oil development and its cyclical expansion and contraction has been premised on a boom/bust social impact model reflecting the experience of resource extraction in communities in the Western United States. In contrast to this literature, we found our subjects perceived far less in the way of disorganizing effects of oil development, and for the most part suggested the impacts to be either benign or positive. There was little support for a boom/bust model of community disruption, and thus we suggest research in this area consider alternative paradigms of interpretation of social impact.
Depressive symptoms and related emotional distress are prevalent among patients with facial neuromuscular disorders, and the psychological distress impacts the functional disabilities associated with ...the facial impairment. A specific impairment in the ability to smile may elevate the risk for depression, with patients experiencing a reduced physiological feedback associated with smiling as well as the social consequences of the inability to communicate positive emotion. We tested the hypothesis that specific impairments in the ability to smile increase the severity of depressive symptoms in patients with facial neuromuscular disorders. Twenty-nine consecutive patients (mean age, 50.2 years; SD, 17.0 years; range, 18-81 years) with a facial neuromuscular disorder, who volunteered and completed all of the assessment measures participated. Facial neuromuscular impairments were assessed using multiple measures of facial motility and dysfunction, and emotional functioning was assessed using self-report measures of depression, anxiety, and positive and negative affect. Severity of global facial impairment was statistically controlled in evaluating the association between specific impairment in smiling and the degree of depressive symptoms. Separate hierarchical linear regression analyses indicated the specific impairment of smiling contributed to the prediction of depression (R(2) =.41, df = 3,25, p =.00) and anxiety (R(2) =.35, df = 3,25, p =.00), controlling first for the contribution of global impairment and facial physical disability. The specific impairment of smiling did not contribute to the prediction of positive emotional experience. Specific impairment of smiling and physical disability, but not global impairment of facial motion, were key predictors of depression in patients with facial neuromuscular disorders. The results emphasize the need to assess and treat depression and anxiety in patients with a facial neuromuscular disorder.
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