General aviation aircraft antennas for the global positioning system

Several antenna designs that utilize the NAVSTAR Global Positioning System in a low-cost system for general aviation aircraft were evaluated. Experimental investigations were made of crossed-dipoles, various types of crossed-slots, and microstrip antennas with modifications to improve their coverage. Principal plane radiation patterns for several of these antennas were measured on a one-seventh scale model of a Gates Lear Jet

Guide to Interpretation of Structural Features Associated with the Kentucky River Fault System Along U.S. Highway 27 Near Camp Nelson, Kentucky

The spectacular, near- vertical roadcuts in the High Bridge Group (Middle Ordovician) in central Kentucky (Fig. 1) along U.S. Highway 27 just south of the Kentucky River (Fig. 2) afford an excellent opportunity to examine a major fault zone and study its complexity (Figs, 3, 4). These roadcuts are located in Garrard County approximately 12 miles south of Lexington and contain the oldest rocks exposed in Kentucky

Radiofrequency transmission characteristics of candidate ablation materials for planetary-entry-vehicle heat shields

Radio frequency transmission characteristics of ablation materials for planetary entry vehicle heat shield

Beta-lysine Discrimination by Lysyl-tRNA Synthetase

Elongation factor P is modified with (R)‐β‐lysine by the lysyl‐tRNA synthetase (LysRS) paralog PoxA. PoxA specificity is orthogonal to LysRS, despite their high similarity. To investigate α‐ and β‐lysine recognition by LysRS and PoxA, amino acid replacements were made in the LysRS active site guided by the PoxA structure. A233S LysRS behaved as wild type with α‐lysine, while the G469A and A233S/G469A variants decreased stable α‐lysyl‐adenylate formation. A233S LysRS recognized β‐lysine better than wildtype, suggesting a role for this residue in discriminating α‐ and β‐amino acids. Both enantiomers of β‐lysine were substrates for tRNA aminoacylation by LysRS, which, together with the relaxed specificity of the A233S variant, suggest a possible means to develop systems for in vivo co‐translational insertion of β‐amino acids

Intrathecal Urokinase as a treatment for intraventricular hemorrhage in the preterm infant

Despite improvements in the care of preterm infants, intraventricular hemorrhage (IVH) and posthemorrhagic hydrocephalus (PHH) continue to be frequent occurrences in this patient population. Shunt procedures in these children are frequently complicated by obstruction and/or infection. As the hydrocephalus is usually caused by an obliterative arachnoiditis due to contact of the blood with the basilar meninges, it was postulated that infusion of urokinase into the ventricles of infants who have sustained an IVH would clear the blood, mitigate the arachnoiditis, and prevent the progression of PHH. Accordingly, 18 preterm infants who had sustained IVH and subsequently developed PHH were treated with intraventricular urokinase instilled via a surgically implanted subcutaneous reservoir. There were no complications associated with the urokinase. Infants were divided into two dosage groups: low dose (110,000–140,000 IU total) and high dose (280,000 IU total). One infant in the low-dose group died at 1 month of life of respiratory complications. In the low-dose group, 3 of 8 (37%) infants required shunt placement; in the high-dose group, all 9 required shunt placement. For the total group, the shunt rate was 71 %. This compares to a historical control group shunt rate of 92%. While the difference between the treatment group as a whole and control group approaches, but does not reach, statistical significance (p = 0.068), there was a significant reduction in the shunt rate when the low-dose group was considered separately (p \u3c 0.002). For those infants that required shunt placement, there were fewer shunt revisions performed in the treatment group than in the control group during the first 24 months following shunt placement: 0.67 versus 1.5 shunt revisions/shunted child. Initial experience with intraventricular urokinase following IVH and PHH in preterm infants suggests a beneficial effect in reducing the shunt revision rate in both high- and low-dose groups. Reduction in shunt placement rate is seen only in the low-dose group

The tRNA Synthetase Paralog PoxA Modifies Elongation Factor-P with (R)-β-lysine

The lysyl-tRNA synthetase paralog PoxA modifies elongation factor P (EF-P) with α-lysine at low efficiency. Cell-free extracts containing non–α-lysine substrates of PoxA modified EF-P with a change in mass consistent with addition of β-lysine, a substrate also predicted by genomic analyses. EF-P was efficiently functionally modified with (R)-β-lysine but not (S)-β-lysine or genetically encoded α-amino acids, indicating that PoxA has evolved an activity orthogonal to that of the canonical aminoacyl-tRNA synthetases

Attitudes and Biases of Health Professionals Toward Individuals with Disabilities: An Evidence-Based Practice Project

This Evidence-Based Practice (EBP) project considered the following question: What are the attitudes and biases of health professionals toward individuals with disabilities and what are the implications for training

Influence of caregiver network support and caregiver psychopathology on child mental health need and service use in the LONGSCAN study

Using structural equation modeling, this study examined the relationship of caregiver network support on caregiver and child mental health need, as well as child mental health service use among 1075 8-year-old children participating in the LONGSCAN study. The final model showed acceptable fit (χ2 = 301.476, df = 136, p<0.001; RMSEA = 0.052; CFI = 0.95). Caregiver and child mental health needs were positively related. As predicted, caregiver network support exerted a protective effect, with greater levels of caregiver network support predictive of lower caregiver and child need. Contrary to prediction, however, caregiver network support was not directly related to child service use. Higher child need was directly related to child service use, especially among children whose caregivers had mental health problems. The findings appear to indicate that lower levels of caregiver network support may exert its impact on child service use indirectly by increasing caregiver and child need, rather than by directly increasing the likelihood of receiving services, especially for African American children