1,341 research outputs found
Historical Forest Landscape Changes in the Buffalo River Sub-Basin in Arkansas
Forested areas in the United States have been altered since the time of European settlement. For this reason, research interests have increased in comparing present day vegetation with that of the preEuroamerican era to see what changes, if any, have occurred in some of our more outstanding natural areas. Such studies have been conducted in other parts of the United States but limited research has been done in Arkansas. The General Land Office (GLO) surveys of Arkansas were originally conducted between approximately 1815 and 1850 shortly after Arkansas was acquired from France by means of the Louisiana Purchase and provides the only systematic on-ground survey in Arkansas that predates most formal botanical investigations. The GLO surveys used witness trees to define the location of section corners and lines. Descriptions of witness trees included tree species and diameter along with distance and direction to the section corner or line. This historical GLO data was compared to United States Forest Service (USFS) Forest Inventory and Analysis (FIA) data, which represent present vegetation conditions for 62 townships in the Buffalo River Sub-basin. Comparisons indicated that eastern red cedar (Juniperus virginiana) increased from 0.7% to 7.8% of the total forest species in the sub-basin, hickory (Carya spp.) increased from 8.2% to 14.3%, while oak (Quercus spp.) species decreased from 43.0% to 30.1%. Based on this study it appears that postEuroamerican settlement fire suppression and agricultural practices in addition to other human activities has caused vegetation changes in this area
A structural perspective of the role of IP6 in immature and mature retroviral assembly
The small cellular molecule inositol hexakisphosphate (IP6) has been known for ~20 years to promote the in vitro assembly of HIV-1 into immature virus-like particles. However, the molecular details underlying this effect have been determined only recently, with the identification of the IP6 binding site in the immature Gag lattice. IP6 also promotes formation of the mature capsid protein (CA) lattice via a second IP6 binding site, and enhances core stability, creating a favorable environment for reverse transcription. IP6 also enhances assembly of other retroviruses, from both the Lentivirus and the Alpharetrovirus genera. These findings suggest that IP6 may have a conserved function throughout the family Retroviridae. Here, we discuss the different steps in the viral life cycle that are influenced by IP6, and describe in detail how IP6 interacts with the immature and mature lattices of different retroviruses
Ariel - Volume 8 Number 3
Executive Editor
James W. Lockard, Jr.
Business Manager
Neeraj K. Kanwal
University News
Richard J . Perry
World News
Doug Hiller
Opinions
Elizabeth A. McGuire
Features
Patrick P. Sokas
Sports Desk
Shahab S. Minassian
Managing Editor
Edward H. Jasper
Managing Associate
Brenda Peterson
Photography Editor
Robert D. Lehman. Jr.
Graphics
Christine M. Kuhnl
Stratigraphy of Cretaceous to Lower Pliocene sediments in the northern part of Cyprus based on comparative 87Sr/86Sr isotopic, nannofossil and planktonic foraminiferal dating
New age data from Sr isotope analysis and both planktonic foraminifera and nannofossils are presented and discussed here for the Upper Eocene–Upper Miocene sedimentary rocks of the Değirmenlik (Kythrea) Group. New dating is also given of some Cretaceous and Pliocene sediments. In a revised stratigraphy the Değirmenlik (Kythrea) Group is divided into ten formations. Different Upper Miocene formations are developed to the north and south of a regionally important, E–W-trending syn-sedimentary fault. The samples were dated wherever possible by three independent methods, namely utilizing Sr isotopes, calcareous nannofossils and planktonic foraminifera. Some of the Sr isotopic dates are incompatible with the nannofossil and/or the planktonic foraminiferal dates. This is mainly due to reworking within gravity-deposited or current-affected sediments. When combined, the reliable age data allow an overall biostratigraphy and chronology to be erected. Several of the boundaries of previously defined formations are revised. Sr data that are incompatible with well-constrained biostratigraphical ages are commonly of Early Miocene age. This is attributed to a regional uplift event located to the east of Cyprus, specifically the collision of the Anatolian (Eurasian) and Arabian (African) plates during Early Miocene time. This study, therefore, demonstrates that analytically sound Sr isotopic ages can yield geologically misleading ages, particularly where extensive sediment reworking has occurred. Convincing ages are obtained when isotopic dating is combined with as many forms of biostratigraphical dating as possible, and this may also reveal previously unsuspected geological events (e.g. tectonic uplift or current activity)
The Ursinus Weekly, May 10, 1954
Political struggles decided at polls: Gene Greenburg heads Curtain Club for \u2755; Bill Stout named new Beardwood prexy; Class, MSGA contests feature close voting • Open scholarship winners announced • Five newcomers join Alpha Psi • Weekly editors interviewed • U.C. men may question aviation cadet team, Thursday • Y officers to be installed at special service Wednesday • Wright, Rack star in The Man... • Chi Alpha to plan picnic at special meeting Wed. • 4 sororities tell officers • Thursday night elections to end Music Club year • Vanderslice delegate to industrial council • Editorials • Letters to the editor • Coed with conflicts asks: What are we to do? • Just thoughts • Bomberger host to initial May Day band concert • May Day pageant received under cloudy skies heartily • Church college offers special advantages • Professor says • Collegeville-Trappe story: Industries • Eshbach\u27s 25.0 in 220 lows snaps his UC hurdle mark • Belles nip Rosemont 3-2; Connie Cross unbowed • Two run rally in eighth gives Drexel 3-2 win • Bears lose to Swarthmore national tennis power, 8-1 • Batgal rally gains 8-7 triumph over W. Chester; Taylor wins • Ricky Bauser to play against British lacrosse squad • Netgals crush Temple foe 4-1; JVs win 5-0 • Knabe\u27s homer, Ors shutout top intramurals • Bruin tracksters mauled in 3-way cinder contest • WSGA, WAA representatives chosen; Soph rulers namedhttps://digitalcommons.ursinus.edu/weekly/1497/thumbnail.jp
Intravascular guidewire coil facilitated invasive real-time magnetic resonance arteriography
The effect of selective phosphodiesterase inhibitors, alone and in combination, on a murine model of allergic asthma
BACKGROUND: The anti-inflammatory effects of the selective phosphodiesterase (PDE) inhibitors cilostazol (PDE 3), RO 20-1724 (PDE 4) and sildenafil (PDE 5) were examined in a murine model of allergic asthma. These compounds were used alone and in combination to determine any potential synergism, with dexamethasone included as a positive control. METHODS: Control and ovalbumin sensitised Balb/C mice were administered orally with each of the possible combinations of drugs at a dose of 3 mg/Kg for 10 days. RESULTS: When used alone, RO 20-1724 significantly reduced eosinophil influx into lungs and lowered tumour necrosis factor-α, interleukin-4 and interleukin-5 levels in the bronchoalveolar lavage fluid when compared to untreated mice. Treatment with cilostazol or sildenafil did not significantly inhibit any markers of inflammation measured. Combining any of these PDE inhibitors produced no additive or synergistic effects. Indeed, the anti-inflammatory effects of RO 20-1724 were attenuated by co-administration of either cilostazol or sildenafil. CONCLUSIONS: These results suggest that concurrent treatment with a PDE 3 and/or PDE 5 inhibitor will reduce the anti-inflammatory effectiveness of a PDE 4 inhibitor
Ariel - Volume 8 Number 2
Executive Editor
James W. Lockard , Jr.
Issue Editor
Doug Hiller
Business Manager
Neeraj K. Kanwal
University News
Richard J. Perry
World News
Doug Hiller
Opinions
Elizabeth A. McGuire
Features
Patrick P. Sokas
Sports Desk
Shahab S. Minassian
Managing Editor
Edward H. Jasper
Managing Associate
Brenda Peterson
Photography Editor
Robert D. Lehman, Jr.
Graphics
Christine M. Kuhnl
Driving Pressure Is Associated With Outcome in Pediatric Acute Respiratory Failure
OBJECTIVES: Driving pressure (ratio of tidal volume over respiratory system compliance) is associated with mortality in acute respiratory distress syndrome. We sought to evaluate if such association could be identified in critically ill children. DESIGN: We studied the association between driving pressure on day 1 of mechanical ventilation and ventilator-free days at day 28 through secondary analyses of prospectively collected physiology data. SETTING: Medical-surgical university hospital PICU. PATIENTS: Children younger than 18 years (stratified by Pediatric Mechanical Ventilation Consensus Conference clinical phenotype definitions) without evidence of spontaneous respiration. INTERVENTIONS: Inspiratory hold maneuvers. MEASUREMENTS AND MAIN RESULTS: Data of 222 patients with median age 11 months (2-51 mo) were analyzed. Sixty-five patients (29.3%) met Pediatric Mechanical Ventilation Consensus Conference criteria for restrictive and 78 patients (35.1%) for mixed lung disease, and 10.4% of all patients had acute respiratory distress syndrome. Driving pressure calculated by the ratio of tidal volume over respiratory system compliance for the whole cohort was 16 cm H2O (12-21 cm H2O) and correlated with the static airway pressure gradient (plateau pressure minus positive end-expiratory pressure) (Spearman correlation coefficient = 0.797; p < 0.001). Bland-Altman analysis showed that the dynamic pressure gradient (peak inspiratory pressure minus positive end-expiratory pressure) overestimated driving pressure (levels of agreement -2.295 to 7.268). Rematching the cohort through a double stratification procedure (obtaining subgroups of patients with matched mean levels for one variable but different mean levels for another ranking variable) showed a reduction in ventilator-free days at day 28 with increasing driving pressure in patients ventilated for a direct pulmonary indication. Competing risk regression analysis showed that increasing driving pressure remained independently associated with increased time to extubation (p < 0.001) after adjusting for Pediatric Risk of Mortality III 24-hour score, presence of direct pulmonary indication jury, and oxygenation index. CONCLUSIONS: Higher driving pressure was independently associated with increased time to extubation in mechanically ventilated children. Dynamic assessments of driving pressure should be cautiously interpreted
Author index for volume 286
Susceptibility to renal injury varies among individuals. Previously, we found that individual endothelial function of healthy renal arteries in vitro predicted severity of renal damage after 5/6 nephrectomy. Here we hypothesized that individual differences in endothelial function in vitro and renal perfusion in vivo predict the severity of renal damage in a model of adriamycin-induced nephropathy. In three separate studies, the following baseline parameters were measured in healthy male Wistar rats: (1) acetylcholine (ACh)-induced relaxation in small renal arteries in vitro (n = 16) and the contribution of prostaglandins, nitric oxide (NO) and endothelium-dependent hyperpolarizing factor (EDHF) to the relaxation; (2) glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) in spontaneously voiding rats in vivo (n = 16) and (3) the acute effect of the NO-synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME, n = 12) on renal blood flow (RBF) as compared to vehicle infusion (n = 9). Following these measurements, adriamycin (1.75 mg/kg i.v.) was injected and subsequent renal damage after 6 weeks was related to the baseline parameters. Total ACh-induced (r = 0.51, P <0.05) and EDHF-mediated relaxation (r = 0.68, P <0.05), as well as ERPF (r = 0.66, P <0.01), positively correlated with the severity of proteinuria 6 weeks after injection. In contrast, pronounced baseline NO-mediated dilation was associated with lower proteinuria (r = 0.71, P <0.01). Nevertheless, an acute L-NAME infusion, strongly reducing RBF by 22 +/- 8%, during adriamycin administration provided protection against the development of proteinuria. Individual animals with pronounced baseline endothelial dilatory ability measured in vitro and high ERPF in vivo are vulnerable to renal damage after the adriamycin injection. Acute inhibition of NO during adriamycin administration, resulting in a decrease of RBF, protects against renal injury, probably by limiting the delivery of the drug to the kidney. Therefore, interindividual variability in renal haemodynamics might be crucially involved in susceptibility to nephrotoxic renal damag
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