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Biomedical subjects

R Boone

Publications and source records attributed to R Boone.

15 recordsLinked to original sources
PubMed2006

An assessment of tree health and trace element accumulation near a coal-fired generating station, Manitoba, Canada.

A forest health assessment was performed in stands dominated by bur oak and trembling aspen to study the potential effects of airborne emissions from a 132 MW coal-fired station. Forty-two stands were sampled within a 16-km radius of the station for both foliar stress symptoms and trace element toxicology. The concentrations of tracer elements (As, Ba, Sr, and V) in the leaf litter were not spatially congruent with airborne emission deposition models (except Ba, which showed elevated levels immediately SE of the station), nor were they at phytotoxic levels. Elemental concentrations were significantly related to soil parameters including organic matter and texture. No patterns were found in forest health along directional or distance gradients from the generating station. Trembling aspen stands demonstrated little decline in general, but three of the 19 bur oak plots, all located on thin sandy soils developed on calcareous till, demonstrated branch dieback. In addition to poor soil conditions, two of these sites also had high water tables, and exhibited tree mortality. The bur oak decline did not appear to be related to emissions from the station, but is suspected to be a result of poor site quality, with urban development as a confounding factor.

Air Pollutants↗
PubMed2001

Infrared patient positioning for stereotactic radiosurgery of extracranial tumors.

We report on a novel, non-invasive patient positioning system for radiosurgery of extracranial tumors. The system consisted of infrared cameras and reflective markers attached to the skin. Because localization accuracy is critical in radiosurgery, we performed a theoretical analysis of the accuracy of the system. A computer simulation program modeled errors in marker position, and was used to predict errors in targeting and study methods for minimizing errors. The use of redundant markers improved the overall accuracy of targeting. Experimental data was collected using a rigid torso phantom and correlated with theoretical results. The accuracy of the infrared system was compared with existing systems.

Computer Simulation↗
PubMed2001

Salmeterol powder provides significantly better benefit than montelukast in asthmatic patients receiving concomitant inhaled corticosteroid therapy.

STUDY OBJECTIVES: Comparison of inhaled salmeterol powder vs oral montelukast treatment in patients with persistent asthma who remained symptomatic while receiving inhaled corticosteroids. DESIGN: Randomized, double-blind, double-dummy, parallel-group, multicenter trials of 12-week duration. SETTING: Outpatients in private and university-affiliated clinics. PATIENTS: Male and female patients > or = 15 years of age with a diagnosis of asthma (baseline FEV(1) of 50 to 80% of predicted) and symptomatic despite receiving inhaled corticosteroids. INTERVENTIONS: Inhaled salmeterol xinafoate powder, 50 microg bid, or oral montelukast, 10 mg qd. MEASUREMENTS AND RESULTS: Treatment with salmeterol powder resulted in significantly greater improvements from baseline compared with montelukast for most efficacy measurements, including morning peak expiratory flow (35.0 L/min vs 21.7 L/min; p < 0.001), percentage of symptom-free days (24% vs 16%; p < 0.001), and the percentage of rescue-free days (27% vs 20%; p = 0.002). Total supplemental albuterol use was decreased significantly more in the salmeterol group compared with the montelukast group (- 1.90 puffs per day vs - 1.66 puffs per day; p = 0.004) and nighttime awakenings per week decreased significantly more with salmeterol than with montelukast (- 1.42 vs - 1.32; p = 0.015). Patients treated with inhaled salmeterol were significantly more satisfied with their treatment regimen and how well, how fast, and how long it worked than were patients who were treated with oral montelukast. The safety profiles for the two treatments were similar. CONCLUSION: In patients with persistent asthma who remain symptomatic while receiving inhaled corticosteroids, adding inhaled salmeterol powder provided significantly greater improvement in lung function and asthma symptoms and was preferred by patients over oral montelukast.

Acetates↗
PubMed1996

Hypertext support for remedial students and students with learning disabilities.

Student use of pop-up text windows that support or extend information found in a high school social studies text provides a detailed look into the instructional effectiveness of a set of hypermedia study guides. Twenty-five students, 19 male and 6 female, with a mean age of 14.6 years participated in this study. Thirteen were students with learning disabilities and 12 were remedial students. Findings from the study indicate that hypertext (text-only) support provides adequate reinforcement to move remedial students and students with learning disabilities toward continued, unprompted use of a hypermedia study guide, and that short-term and long-term retention of information can be expected from text-only information support. Students who had access to the hypermedia study guides exhibited better information retention than students who did not use the hypermedia study guides.

Adolescent↗
PubMed1993

Characterization of three de novo derivative chromosomes 16 by "reverse chromosome painting" and molecular analysis.

We have analyzed three de novo chromosome 16 rearrangements--two with a 16p+ chromosome and one a 16q+--none of which could be fully characterized by conventional cytogenetics. In each case, flow karyotypes have been produced, and the aberrant chromosome has been isolated by flow sorting. The origin of the additional material has been ascertained by amplifying and labeling the DNA of the abnormal chromosome by degenerate-oligonucleotide-primer-PCR and hybridizing it in situ to normal metaphase spreads (reverse chromosome painting). Both 16p+ chromosomes contain more than 30 Mb of DNA from the short arm of chromosome 9(9p21.2-pter), while the 16q+ contains approximately 9 Mb of DNA from 2q37. The breakpoints on chromosome 16 have been localized in each case; the two breakpoints on the short arm are at different points within the terminal band, 16p13.3. The breakpoint on the long arm of chromosome 16 is very close to (within 230 kb of) the 16q telomere. Determination of the regions of monosomy and trisomy allowed the observed phenotypes to be compared with other reported cases involving aneuploidy for these regions.

Adolescent↗
PubMed1990

Hypertext computer study guides and the social studies achievement of students with learning disabilities, remedial students, and regular education students.

Hypertext is a relatively new term for today's teachers, who work hard to stay abreast of the quickly changing field of computer technology in education. Hypertext as an educational tool is very different from traditional computer-assisted instructional software, offering the reader immediate access through its computer format to supplemental information. Two related studies were conducted to design and field-test hypertext computer study guides. In Study 1, 40 students (10 with learning disabilities, 15 remedial, and 15 regular education) worked in three different treatment groups (lecture, lecture/computer study guide, and computer study guide). Study 2 involved the five lowest achieving students (two with learning disabilities and three remedial) from Study 1 in an A-B-A design. Results indicated that (a) the computer study guide treatment was as effective as lecture, (b) the lecture/computer study guide treatment was as effective as lecture, (c) posttest scores were higher for the computer study guide group, and (d) retention test scores were higher for the computer study guide group.

Achievement↗
PubMed1984

Reaction of azapeptides with human leukocyte elastase and porcine pancreatic elastase. New inhibitors and active site titrants.

The reaction of a series of azapeptides with porcine pancreatic (PP) elastase and human leukocyte (HL) elastase has been studied and a series of new inhibitors and active site titrants were found for both PP elastase and HL elastase. Azapeptide p-nitrophenyl esters acylate both HL and PP elastase to form stable acylenzymes, which can be used for crystallographic studies. We have investigated the effect of a P1, P2, or P3 aza-amino acid residue on the reactivity of azapeptides with elastase. We have also studied the effect of changing the nature of the P1' leaving group and other portions of azapeptide structure. N-Acetyl-L-alanyl-L-alanyl-alpha-azaalanine p-nitrophenyl ester, N-acetyl-L-alanyl-L-alanyl-alpha-azanorleucine p-nitrophenyl ester, and N-acetyl-L-alanyl-L-alanyl-alpha-azanorvaline p-nitrophenyl ester are suitable titrants for either PP or HL elastase.

Animals↗
PubMed1976

A transient thermotolerant survival response produced by single thermal doses in HeLa cells.

Continuous exposure of HeLa cells in culture to elevated temperatures (41-45 degrees) results in cell killing which increases exponentially as the time at the elevated temperature increases linearly. When cells are returned to 37 degrees after an initial thermal dose, cellular sensitivity to subsequent hyperthermic doses is reduced. Cell inactivation rates for cultures previously treated with 44 degrees for either 0.5 or 1 hr followed by incubation at 37 degrees for 2 hr, showed D0's of 1.1 and 1.5 hr, respectively, for subsequent thermal treatments at 44 degrees. Cultures receiving no prior hyperthermic dose had a D0 of 0.5 hr for treatments at 44 degrees for up to 3.5 hr. The viable progeny of cells treated with 44 degrees for 1 hr, however, had the same sensitivity to thermal doses at 44 degrees as did previously unheated cells. These results and others demonstrate that (a) single thermal dose produce a state of thermotolerance in HeLa cells to subsequent hyperthermic doses; (b) the degree of thermotolerance produced is dependent on the magnitude (i.e., temperature and time at the elevated temperature) of the first thermal dose; (cy thermotolerance does not develop at the elevated temperature but requires a return of culture temperatures to 37 degrees; (d) cellular acquisition of thermal tolerance is dependent on cell metabolism, as demonstrated by an inhibition of the effect at 0 degrees; and (e) this effect is a transient phenomenon which is lost as cells divide following the first thermal dose.

Cell Division↗