The effects of canopy density and vegetative competition on oak seedling numbers in southeastern Ohio

The regeneration of oak species in the forest setting has been a current issue for foresters. Oak-hickory forests are currently the dominant cover type in most parts of the Eastern Hardwood Region, but the lack of regeneration in the understory is hinting toward a reduction in the number of oaks. The data shows the oaks are regenerating as seedlings but there are few oaks in the sapling stage. The oaks do not occur in the sapling stage as the result of the oak seedlings are succumbing to competition by other vegetation at young ages. This study focused on how canopy cover and the competing vegetation affected oak seedlings in a natural forest. The competing vegetation showed that as red maple and other hardwoods species increase in numbers and canopy area, the less oak seedlings that are present in the seedling category. Advisor: Dr. Roger William

THE EFFECT OF INSPIRED OXYGEN CONCENTRATION ON INTRAPULMONARY RIGHT-TO-LEFT SHUNT DURING POSTOPERATIVE MECHANICAL VENTILATION

A consecutive series of patients undergoing cardiac surgery for valve replacement was divided into two groups. The first underwent postoperative artificial ventilation using the oxygen-driven Bird ventilator. The inspiratory oxygen concentration was 83%. In the second group a Bird ventilator was also used but with an oxygen concentration of 40%. In the first group the intrapulmonary right-to-left shunt rose to an average of 17% during the first two postoperative daysand in the second group to an average of 9%. The study supports the view that the inspiratory oxygen concentration should only be kept high enough to achieve a normal oxygen saturation of arterial bloo

Satellite geological and geophysical remote sensing of Iceland: Preliminary results from analysis of MSS imagery

A binational, multidisciplinary research effort in Iceland is directed at an analysis of MSS imagery from ERTS-1 to study a variety of geologic, hydrologic, oceanographic, and agricultural phenomena. A preliminary evaluation of available MSS imagery of Iceland has yielded several significant results - some of which may have direct importance to the Icelandic economy. Initial findings can be summarized as follows: (1) recent lava flows can be delineated from older flows at Askja and Hekla; (2) MSS imagery from ERTS-1 and VHRR visible and infrared imagery from NOAA-2 recorded the vocanic eruption on Heimaey, Vestmann Islands; (3) coastline changes, particularly changes in the position of bars and beaches along the south coast are mappable; and (4) areas covered with new and residual snow can be mapped, and the appearance of newly fallen snow on ERTS-1, MSS band 7 appears dark where it is melting. ERTS-1 imagery provides a means of updating various types of maps of Iceland and will permit the compilation of special maps specifically aimed at those dynamic environmental phenomena which impact on the Icelandic economy

T-cell Apoptosis in Human Glioblastoma Multiforme: Implications for Immunotherapy

We used immunohistochemistry and flow cytometry to assess apoptosis in human glioblastoma multiforme (GBM). Our immunohistochemical study revealed apoptosis of glioma cells expressing glial fibrillary acidic protein and of CD3+ T cells infiltrating GBM. To quantify and phenotype the apoptotic T cells, we performed flow cytometry on lymphocytes separated from GBM. The cells were stained with annexin-V-FLUOS/propidium iodide to identify apoptosis. We found that high proportions of both the CD4+ and CD8+ T cells were apoptotic. In particular, we found that T cells expressing Fas ligand (Fas-L, CD95L) were eight times more vulnerable to apoptosis than those not expressing Fas-L, which suggests that the T-cell apoptosis is induced by overactivation of the T-cell receptor, possibly in the absence of appropriate costimulation. Our results have implications for the design of immunotherapies for GBM

Satellite geological and geophysical remote sensing of Iceland: Preliminary results of geologic, hydrologic, oceanographic, and agricultural studies with ERTS-1 imagery

The author has identified the following significant results. The wide variety of geological and geophysical phenomena which can be observed in Iceland, and particularly their very direct relation to the management of the country's natural resources, has provided great impetus to the use of ERTS-1 imagery to measure and map the dynamic natural phenomena in Iceland. MSS imagery is being used to study a large variety of geological and geophysical eruptive products, geologic structure, volcanic geomorphology, hydrologic, oceanographic, and agricultural phenomena of Iceland. Some of the preliminary results from this research projects are: (1) a large number of geological and volcanic features can be studied from ERTS-1 imagery, particularly imagery acquired at low sun angle, which had not previously been recognized; (2) under optimum conditions the ERTS-1 satellite can discern geothermal areas by their snow melt pattern or warm spring discharge into frozen lakes; (3) various maps at scales of 1:1 million and 1:500,000 can be updated and made more accurate with ERTS-1 imagery; (4) the correlation of water reserves with snowcover can improve the basis for planning electrical production in the management of water resources; (5) false-color composites (MSS) permitted the mapping of four types of vegetation: forested; grasslands, reclaimed, and cultivated areas, and the seasonal change of the vegetation, all of high value to rangeland management

REGULATION OF CORONARY BLOOD FLOW DURING ETHER AND HALOTHANE ANAESTHESIA

SUMMARY The effects of ether (6-10%) and halothane (1-2%) were studied on coronary flow regulation in dogs. In one group of experiments the kft coronary artery was perfused mechanically, coronary perfusion pressure being either kept constant or adjusted to aortic pressure, and the heart itself had to pump the blood to all other arteries. The preload on the heart was changed by varying die intravascular volume. In another group, bodi coronary arteries were perfused mechanically under constant pressure; the other arteries were also perfused mechanically by a cardiopulmonary bypass. In this group measurements were carried out on the empty beating heart. Halothane had a direct effect on die heart, myocardial contractility was reduced, cardiac work and myocardial oxygen consumption were diminished and coronary vasoconstriction followed. Edier effects on the heart were principally die same as diose due to halodiane, but to a lesser degree. Coronary vasoconstriction caused by halodiane did not produce myocardial hypoxia. Coronary vasoconstriction occurred as an autorcgulatory mechanism preventing "unnecessary ” hyperperfusion as long as cardiac work and oxygen consumption were diminished. Bodi edier and halodiane reduced systemic vascular resistanc

Modelling the molecular composition and nuclear-spin chemistryof collapsing pre-stellar sources★

We study the gravitational collapse of pre-stellar sources and the associated evolution of their chemical composition. We use the University of Grenoble Alpes Astrochemical Network (UGAN), which includes reactions involving the different nuclear-spin states of H2, H+3 , and of the hydrides of carbon, nitrogen, oxygen, and sulphur, for reactions involving up to seven protons. In addition, species-to-species rate coefficients are provided for the ortho/para interconversion of the H +3 + H2 system and isotopic variants. The composition of the medium is followed from an initial steady state through the early phase of isothermal gravitational collapse. Both the freeze-out of the molecules on to grains and the coagulation of the grains were incorporated in the model. The predicted abundances and column densities of the spin isomers of ammonia and its deuterated forms are compared with those measured recently towards the pre-stellar cores H-MM1, L16293E, and Barnard B1. We find that gas-phase processes alone account satisfactorily for the observations, without recourse to grain-surface reactions. In particular, our model reproduces both the isotopologue abundance ratios and the ortho:para ratios of NH2D and NHD2 within observational uncertainties. More accurate observations are necessary to distinguish between full scrambling processes – as assumed in our gas-phase network – and direct nucleus- or atom-exchange reactions

The Most Commonly Occurring Papillary Thyroid Cancer in the United States Is Now a Microcarcinoma in a Patient Older than 45 Years

Background: The incidence of papillary thyroid cancer (PTC) is growing at a faster rate than any other malignancy. However, it is unknown what effect age is having on the changing PTC incidence rates. With the goal of understanding the role of age in thyroid cancer incidence, this study analyzes the changing demographics of patients with PTC over the past three decades. Methods: This was a retrospective evaluation of the incidence rates of PTC from 1973 to 2006 reported by the National Cancer Institute's Surveillance, Epidemiology, and End Results database. Results: From 1973-2006 the age group most commonly found to have PTC has shifted from patients in their 30s to patients in the 40-50-year-old age group. In 1973 60% of PTC cases were found in patients younger than 45, and the majority of cases continued to occur in younger patients until 1999. After 1999 PTC became more common in patients older than 45 years, and in 2006, 61% of PTC cases were in patients older than 45 years. From 1988 to 2003 there has been an increasing incidence of all sizes of PTC in all age groups with the largest increase in tumors <1-cm in patients older than 45. Forty-three percent of tumors in patients older than 45 are now <1-cm, whereas only 34% are <1-cm in patients younger than 45. Of the nearly 20,000 thyroid cancer cases in 2003, 24% were microcarcinomas in patients over the age of 45. Conclusions: The incidence of PTC is increasing disproportionally in patients older than 45 years. The number of PTC tumors smaller than 1-cm is increasing in all age groups, and now the most commonly found PTC tumor in the United States is a microcarcinoma in a patient older than 45 years. These changing patterns relating age and incidence have important prognostic and treatment implications for patients with PTC.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90466/1/thy-2E2010-2E0137.pd

Preoperative predictors of recurrent atrial fibrillation late after successful mitral valve reconstruction

Objective: Late outcome after mitral valve repair was examined to define preoperative predictors of recurrent atrial fibrillation late after successful mitral valve reconstruction. Methods: One hundred and eighty-nine patients, 112 with preoperative sinus rhythm and 72 with preoperative chronic or intermittent atrial fibrillation, were followed for 12.2±10 years after valve repair. Clinic, hemodynamic end echocardiographic data were entered into Cox-regression and Kaplan-Meyer analysis to assess predictors for recurrent atrial fibrillation late after successful mitral valve repair. Results: Univariate and multivariate predictors for recurrent atrial fibrillation late after successful mitral valve reconstruction were preoperative atrial fibrillation (P=0.0001), preoperative antiarrhythmic drug treatment (P=0.005), heart rate (P=0.01), left ventricular ejection fraction (P=0.01) and increased left ventricular posterior wall thickness (P=0.05). Patients>57.5 years with a mean pulmonary artery pressure ≥23mm Hg and a history of preoperative antiarrhythmic drug treatment had an odds ratio of 53.33 (95% confidence limits 6.12-464.54) for atrial fibrillation late after successful mitral valve repair. Conclusion: Older patients with a history of atrial fibrillation, antiarrhythmic treatment or an elevated pulmonary artery pressure may present atrial fibrillation late after successful mitral valve repair. They could be considered for combined mitral valve reconstruction and surgery for atrial fibrillation even though sinus rhythm is present preoperativel

Investigation and prediction of the bending of single and tandem pillars in a laminar cross flow

Cantilever beams are increasingly applied as sensory structures for force and flow measurements. In nature, such hair-like mechanoreceptors often occur not as single hairs but in larger numbers distributed around the body-surface and with different mechanical properties. In addition, reconfiguration of such structures with the flow changes their response and mutual interaction. This raises the question how it affects the signal conditioning on each individual sensor. Simple configurations involving single and tandem pairs of flexible cylinders (of aspect ratio 10) are studied as elementary units of such sensor arrays at Reynolds numbers of order Red=O(1–10). Experimental reference studies were carried out with a tandem pair of up-scaled models using flexible cylinders mounted on a flat plate and towed in a viscous liquid environment. Direct numerical simulations (DNS) are used to determine the local drag along the rigid cylinders (pillars) for different orientations of the tandem relative to the main flow direction at steady flow conditions. The bending is then computed via beam bending theory. A prediction model based on the cross-flow velocity and an empirical relation for the drag coefficient is proposed and tested. The results show good agreement of the bending lines with the experiments and the direct numerical simulations for single and tandem configurations. It is then used to illustrate the expected sensor response at any point in a given complex flow field. This study contributes to the understanding of pre-conditioning effects in a sensor array measuring near-wall flow