Pulmonary diffusing capacity for nitric oxide (DLNO) is a relatively new pulmonary function test to assess gas transfer in the lung. To date, there are no prediction equations made for healthy adult African-American (black) subjects. Thus, the purpose of this study was to create prediction equations for DLNO in this ethnic/racial group. A total of 59 healthy subjects (27 males and 32 females) were recruited to perform pulmonary function testing at Georgia State University. They were diverse in age (18-67 yr), height (140-189 cm), and body mass index (17.2-32.3 kg/m2). All subjects completed single-breath maneuvers at rest inhaling 43 ± 4 ppm NO with a standard diffusion mixture. The breath-hold duration was 5.6 ± 0.6 s. Multiple linear regression predicted DLNO based on the subject’s age, height, and sex. The prediction equation for DLNO (mL/min/mmHg) = 0.92·(height in cm) +38.8·(sex) – 0.012·(age2) – 25, where 1 = male, 0 = female for sex. About 77% of the variance in DLNO was accounted for by sex (67%), age2 (7%), and height (4%). The standard error of the estimate in predicting DLNO was 16.3 mL/min/mmHg. Those with higher resting heart rates had a lower DLNO (r =-0.28, p = 0.03) but it was not included in the regression model as it did not enhance the fit. Black males had a 7-10% lower DLNO and black females had a 12-15% lower DLNO compared to matched white subjects. Black males of the same age and height had a 10% smaller alveolar volume, while black females had a 15% lower alveolar volume compared to matched white subjects. In conclusion, DLNO values and alveolar volumes are reduced in blacks compared to matched whites. The regression model presented best predicts DLNO in African-Americans below 40 years of age.

Understanding human spatial cognition and behaviour is not something easily studied. Many factors are involved that contribute in different ways for different individuals. Navigation and wayfinding have been used as an approach, or starting point, for such studies. Spatial abilities tests have long been used as reference points to generalize to overt navigational behaviour. Care needs to be taken in generalizing from paper to behaviour to make certain that it is a valid relationship exists.<p>The purpose of this study was to examine the extent to which certain psychometric spatial abilities tests are indicators of actual navigational decision making. The study was conducted in two phases. The navigational decision tasks were made up of four paths with two variables: length and number of turns. The participants were required to make a decision on which direction to go after being lead part of the way around a hallway. The choices were to either go back the way they were led or take a novel route along a previously un-travelled path (shortcut). Spatial abilities tests (MRT, PFT, and OLMT), a self-rating of SOD, and learning preference for novel environments were administered in phase two. <p>While efficient navigation was not explicitly required in the navigation tasks those participants making the most efficient decisions shared similar characteristics. Efficient navigators have a higher aptitude for mental manipulation (as measured by the MRT), express a preference for a more exploratory environmental learning style, are disproportionately male, and have a slightly higher self-rating of SOD. In addition to the collective set of four navigation decisions (one for each experimental path), path 2 demonstrated the efficient vs. non-efficient distinction quite well: in order to make the most efficient decision the individual must maintain the correct metric distance from the origin point and not be deterred by the passage of only half of the turns in the rectangular experimental environment.

Understanding human spatial cognition and behaviour is not something easily studied. Many factors are involved that contribute in different ways for different individuals. Navigation and wayfinding have been used as an approach, or starting point, for such studies. Spatial abilities tests have long been used as reference points to generalize to overt navigational behaviour. Care needs to be taken in generalizing from paper to behaviour to make certain that it is a valid relationship exists.<p>The purpose of this study was to examine the extent to which certain psychometric spatial abilities tests are indicators of actual navigational decision making. The study was conducted in two phases. The navigational decision tasks were made up of four paths with two variables: length and number of turns. The participants were required to make a decision on which direction to go after being lead part of the way around a hallway. The choices were to either go back the way they were led or take a novel route along a previously un-travelled path (shortcut). Spatial abilities tests (MRT, PFT, and OLMT), a self-rating of SOD, and learning preference for novel environments were administered in phase two. <p>While efficient navigation was not explicitly required in the navigation tasks those participants making the most efficient decisions shared similar characteristics. Efficient navigators have a higher aptitude for mental manipulation (as measured by the MRT), express a preference for a more exploratory environmental learning style, are disproportionately male, and have a slightly higher self-rating of SOD. In addition to the collective set of four navigation decisions (one for each experimental path), path 2 demonstrated the efficient vs. non-efficient distinction quite well: in order to make the most efficient decision the individual must maintain the correct metric distance from the origin point and not be deterred by the passage of only half of the turns in the rectangular experimental environment.

No description available.

Les biomes herbacés africains intertropicaux devraient faire face, dans un proche futur, à des changements drastiques. Les modèles dynamiques de végétation (DGVM) ont des difficultés à simuler les limites actuelles de ces biomes, notamment parce qu’ils ne prennent pas en compte la diversité des couverts herbacés en C4. Il est donc nécessaire de caractériser cette diversité floristique et physionomique afin qu’elle puisse être facilement prise en compte dans les DGVMs, et que les comparaisons modèle/données (phytolithes) soient possibles.Dans cet objectif, les traits physionomiques des graminées en C4 dominantes au Sénégal et en Afrique du Sud ont été répertoriés. Quatre groupes physionomiques ont été statistiquement discriminés. Ils varient avec la distribution spatiale des biomes et les précipitations régionales. Deux groupes sont fortement corrélés à l’indice de surface foliaire (LAI) et à la biomasse herbacée. Au Sénégal ces deux groupes sont bien différenciés par l’indice phytolithique Iph qui est un proxy des couverts herbacés intertropicaux. En Afrique du Sud, les phytolithes n’ont pas permis de tracer l’ensemble de la transition savane/steppe. Ces deux groupes physionomiques remplissent les critères nécessaires à la caractérisation de types fonctionnels de plantes (PFT). L’intégration de ces PFTs dans le modèle LPJ-GUESS améliore la simulation des biomes herbacés actuels et permet de proposer des simulations pour l’horizon 2100. Ces simulations montrent que l’augmentation de la durée de la saison sèche et de la concentration en CO2 atmosphérique devraient favoriser l’expansion simultanée des steppes et des savanes fermées aux dépens des savanes ouvertes. / Intertropical african herbaceous biomes are expected to face drastic changes in a near future. However Dynamic Global Vegetation Models (DGVMs) simulate their modern boundaries with poor accuracy, especially at the regional scale. DGVMs fail to consider the diversity of their C4 grass cover. Efforts are thus needed to characterize this floristic and physiognomic diversity in a way that can be used for enhancing DGVMs simulations, and enabling model/data (phytoliths) comparisons. For that purpose, physiognomic traits of dominant C4 grass species settled in Senegal and South Africa were listed. Four grass physiognomic groups were statistically identified. The abundance of four of them significantly varied with biome distributions and regional precipitation. Two grass physiognomic groups were additionally strongly correlated with leaf area index (LAI) and grass biomass. In Senegal, those two groups were also well traced by the Iph phytolith index which is a tropical grass cover proxy. In South Africa the limited set of phytolith data did not allow to observe the full savanna/steppe transition. The two physiognomic groups finally fulfilled the criteria required for creating Plant Functional Types (PFTs). Those new PFTs, parameterized in the LPJ-GUESS DGVM, enhanced the simulation of modern herbaceous biomes distribution in Senegal and South Africa. Simulations were additionally performed for the 2100 horizon. They evidence that the increase of both length of the dry season and atmospheric CO2 concentration should favor the simultaneous spread of steppes and closed savannas at the expense of open savannas.

Summary: This diploma thesis deals with the relation between autoimmune processes at biological level (through proven neurological autoimmune disease - multiple sclerosis) and possible autoaggressive processes at the mental level. It is divided into several points. The first one introduces human immunity in general. The first part is followed by immune system description, including autoimmunity and the principle of diseases of this system. Thereafter, psychological aggression is described, in which the division into aggression and auto- aggression fits. This is followed by chapters on projective psychodiagnostics taking into account the detection of various forms of aggression. Then, the thesis focuses on the study of possible auto-aggressive manifestations in patients suffering from the most widespread neurological autoimmune disease, multiple sclerosis. The second half of the thesis describes the author's research on this topic.

Idiopathic pulmonary fibrosis (IPF) is an irreversible disease of unknown etiology that involves progressive scarring of the lung tissue, leading to respiratory failure and death.1 IPF is thought to develop from repetitive lung injury and aberrant wound healing that leads to the generation of fibrous tissue rather than restoration of normal tissue.2 It has been suggested in mice that vascular leak after lung injury contributes to the development of lung fibrosis.2,3 Gadofosveset is an intravascular enhancing, gadolinium-based contrast agent used with magnetic resonance imaging (MRI) to assess a variety of biological processes in vivo because it can reversibly bind to albumin.13-14 Gadofosveset has been used to assess endothelial permeability and function, as it diffuses through the vessel walls via leaky neovessels and damaged endothelium.15 Our research group has developed a new method to assess disease activity in IPF patients using gadofosveset-enhanced lung MRI. In unpublished work, we have demonstrated that this technique can be used to generate an albumin extravasation index (AEI), and we have found that this is significantly and diffusely increased in the lung of patients with idiopathic pulmonary fibrosis compared to healthy controls.16 The AEI is a measure of the change in signal intensity post-contrast minus pre-contrast in predefined regions of interest (ROIs) in the lung parenchyma divided by post- minus pre-contrast signal intensity in the ROI in the aorta. In this study, we compared the AEI in patients with IPF to healthy control (HC) subjects and evaluated the correlation between the AEI and high-resolution computed tomography (HRCT) and pulmonary function testing (PFT). We found that IPF subjects had increased AEI values compared with HC subjects. While not statistically significant, AEI was more strongly correlated with fibrosis (interstitial abnormalities) than ground-glass (alveolar abnormalities) on HRCT. Furthermore, there was a possible correlation between AEI and change in percent predicted forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and diffusion capacity of carbon monoxide adjusted for hemoglobin (DLCO) [Hb]. Our results demonstrate that AEI calculations from gadofosveset-enhanced lung MRI are a surrogate measure of vascular leak and can potentially serve as an alternative method for predicting the clinical course and severity of IPF through its correlation with fibrosis on HRCT and pulmonary function.

The use of Dynamic Global Vegetation Models (DGVMs) in paleo-vegetation studies is a practical new approach in paleo-ecology as it allows for process-based investigations within a flexible framework. The goal of this study is to evaluate the applicability of Lund Potsdam Jena (LPJ) – DGVM in a paleo-study of Cretaceous angiosperm spread, while testing several pre-existing theories regarding the spread through model experimentation. I assessed the independent and interactive role of climate variables (temperature, precipitation, atmospheric CO2 concentration, and seasonality), latitudinal light regime, soil structure, and plant characteristics (tree versus grass, and deciduousness) in influencing angiosperm expansion by simulating the response of Cretaceous land cover to changes in each factor. I found that temperature and light were the most influential variables in determining angiosperm success, while plant structure and deciduousness may carry implications for early angiosperm establishment and community competition dynamics. LPJ showed great potential for refinement and effective future use in paleo-applications.

The use of Dynamic Global Vegetation Models (DGVMs) in paleo-vegetation studies is a practical new approach in paleo-ecology as it allows for process-based investigations within a flexible framework. The goal of this study is to evaluate the applicability of Lund Potsdam Jena (LPJ) – DGVM in a paleo-study of Cretaceous angiosperm spread, while testing several pre-existing theories regarding the spread through model experimentation. I assessed the independent and interactive role of climate variables (temperature, precipitation, atmospheric CO2 concentration, and seasonality), latitudinal light regime, soil structure, and plant characteristics (tree versus grass, and deciduousness) in influencing angiosperm expansion by simulating the response of Cretaceous land cover to changes in each factor. I found that temperature and light were the most influential variables in determining angiosperm success, while plant structure and deciduousness may carry implications for early angiosperm establishment and community competition dynamics. LPJ showed great potential for refinement and effective future use in paleo-applications.

The use of sulfur hexafluoride (SF6) as a tracer gas for analyzing underground mine ventilation systems has been practiced for over 30 years. As a result, the methods used to release, sample, and analyze SF6 are well accepted. Although improvements are still being made to enhance the analysis of this tracer, the overall technique remains largely the same. However, as the complexity and size of underground mine ventilation networks increase, coupled with steadily rising SF6 background levels, the ability of a single gas to function as a convenient, rapid means of analysis diminishes. The utilization of multiple tracer gases can mitigate these problems by allowing for a more comprehensive evaluation using multi-zone techniques. A well-documented alternative in HVAC studies to SF6 as a tracer are perfluorocarbon tracers (PFT). Many PFTs exist as volatile liquids at room temperature and pressure. This characteristic prevents a PFT from being released using the same technique as SF6. This paper introduces a passive release method for PMCH. Details about the development of the permeation plug release vessel (PPRV) from creating a GC calibration curve for vapor PMCH to the final field evaluation are presented. The following study successfully developed a mine-scale PPRV. The PPRV is designed to passively deploy PMCH vapor at linear. An equation was derived in this study that allows the prediction of the release rate as a function of temperature and plug thickness. Details regarding the development of the PPRV from preliminary laboratory studies to final field evaluations are provided. / Ph. D.