NICMOS Observations of Low-Redshift Quasar Host Galaxies

We have obtained Near-Infrared Camera and Multi-Object Spectrometer images of 16 radio quiet quasars observed as part of a project to investigate the ``luminosity/host-mass limit.'' The limit results were presented in McLeod, Rieke, & Storrie-Lombardi (1999). In this paper, we present the images themselves, along with 1- and 2-dimensional analyses of the host galaxy properties. We find that our model-independent 1D technique is reliable for use on ground-based data at low redshifts; that many radio-quiet quasars live in deVaucouleurs-law hosts, although some of the techniques used to determine host type are questionable; that complex structure is found in many of the hosts, but that there are some hosts that are very smooth and symmetric; and that the nuclei radiate at ~2-20% of the Eddington rate based on the assumption that all galaxies have central black holes with a constant mass fraction of 0.6%. Despite targeting hard-to-resolve hosts, we have failed to find any that imply super-Eddington accretion rates.Comment: To appear in ApJ, 28 pages including degraded figures. Download the paper with full-resolutio figures from http://www.astro.wellesley.edu/kmcleod/mm.p

An exploration into the client at the heart of therapy : a qualitative perspective

Over 50 years ago Eysenck challenged the existing base of research into psychotherapy. Since that time, a large number of investigations have been conducted to verify the efficacy of therapy. Recently however, an increasing number of studies have cast new doubts on this research base. Instead of therapy being a function of the therapist, it is now becoming ever more apparent that the client plays a prime role in the therapeutic process. The qualitative studies presented in this paper provide some examples of research that demonstrates that clients are actively involved in their therapy, even making counselling work despite their counsellor. These studies suggest that clients may not experience therapy as beneficially as traditional outcome studies indicate. This raises a new challenge to researchers to more fully explore the client's experience of therapy, a challenge to which qualitative methods of inquiry would appear well suited

LANDSAT Digital Data Base Preparation for the Pennsylvania Defoliation Application Pilot Test

A LANDSAT digital mosaic data base for the State of Pennsylvania was prepared for use in the development of an automated system to annually estimate the extent and severity of Gypsy Moth defoliation of hardward forests. The techniques for detecting the defoliation and development of a geographic information system (GIS) to assess damage is being developed jointly by NASA/Goddard Space Flight Center and Pennsylvania State University using the JPL prepared mosaic base. The JPL processing involved the use of ground control points from the Master Data Processor for planimetric control, resampling of the LANDSAT data to 57 x 57 meter pixels, realignment to north, and reprojection to the Universal Transverse Mercator (UTM) projection in UTM zones 17 and 18. The completed mosaic for each UTM zone was subdivided into 1 degree of latitude by 2 degrees of longitude quadrangles for easy data handling. Consideration is given to the issues of mapping standards, sensor and spacecraft platform characteristics, and their implication to geographic information systems operation. Methods for obtaining measures of accuracy for LANDSAT mosaics are reviewed

Oil Spill Containment and Removal in Arctic Ecosystems

Statistics on 16 arctic and subarctic oil spills, their locations, the amount of oil spilled, combatant schemes used, and causes for the spills were culled from the literature. This information has been used to analyze the effectiveness of available chemical, mechanical, and destructive means of oil recovery or disposal under arctic and subarctic conditions. The choice of the best cleanup procedures to follow in any particular instance is clouded by a number of variables and must be weighed against such considerations as wind, sea, and ice conditions, properties of the oil, and effects of chemicals on marine and wildlife. Access to remote arctic sites may well create a major difficulty. Some recommendations for further research on these problems are also given

Whiskerless Schottky diode

A Schottky diode for millimeter and submillimeter wave applications is comprised of a multi-layered structure including active layers of gallium arsenide on a semi-insulating gallium arsenide substrate with first and second insulating layers of silicon dioxide on the active layers of gallium arsenide. An ohmic contact pad lays on the silicon dioxide layers. An anode is formed in a window which is in and through the silicon dioxide layers. An elongated contact finger extends from the pad to the anode and a trench, preferably a transverse channel or trench of predetermined width, is formed in the active layers of the diode structure under the contact finger. The channel extends through the active layers to or substantially to the interface of the semi-insulating gallium arsenide substrate and the adjacent gallium arsenide layer which constitutes a buffer layer. Such a structure minimizes the effect of the major source of shunt capacitance by interrupting the current path between the conductive layers beneath the anode contact pad and the ohmic contact. Other embodiments of the diode may substitute various insulating or semi-insulating materials for the silicon dioxide, various semi-conductors for the active layers of gallium arsenide, and other materials for the substrate, which may be insulating or semi-insulating

Algorithms for Linear Time Series Analysis: With R Package

Our ltsa package implements the Durbin-Levinson and Trench algorithms and provides a general approach to the problems of fitting, forecasting and simulating linear time series models as well as fitting regression models with linear time series errors. For computational efficiency both algorithms are implemented in C and interfaced to R. Examples are given which illustrate the efficiency and accuracy of the algorithms. We provide a second package FGN which illustrates the use of the ltsa package with fractional Gaussian noise (FGN). It is hoped that the ltsa will provide a base for further time series software.

Coronary artery remodelling, atherosclerosis and vascular function

OBJECTIVES: The aims of the thesis were to assess coronary artery remodelling and plaque load, and to determine whether this influences vascular and endothelial function in vivo in man.METHODS: Coronary artery remodelled segments were categorised using intravascular ultrasound (IVUS). Plaque type was characterised directly from spectral analysis of the radiofrequency ultrasound signal. Central arterial stiffness was assessed using non-invasive measures of arterial stiffness obtained by applanation tonometry of the radial, carotid and femoral artery. Coronary artery plaque volume was determined following computerised three-dimensional reconstruction of IVUS images obtained during a motorised pullback device. Coronary vessel area, arterial stiffness and vasomotor responses were determined using IVUS and Doppler Flow measurement and endothelial fibrinolytic responses by coronary sinus sampling during selective intracoronary infusions.RESULTS: Plaque characteristics Positively remodelled segments had a larger vessel area (16.5±1.1 mm2 vs. 8.7±0.9 mm2, p<0.01) and plaque area (7.3+1.1 mm2 vs. 4.4+0.8 mm2, p=0.05) than negatively remodelled segments. Both positive and negatively remodelled segments had a greater percentage of fibrous plaque (p<0.01) than calcified or lipid rich plaque. Comparing positively and negatively remodelled segments, there was no significant difference between the proportion of fibrous, calcified and lipid rich plaque. Comparisons with non-invasive measures Plaque volume positively correlated with carotid-radial pulse wave velocity (r=0.47, p=0.008) and appeared to correlate with carotid-femoral pulse wave velocity (r=0.34, p=0.07). Aortic augmentation (r=0.24, p=0.16), augmentation index (r=0.3, p=0.08), and pulse pressure (r=0.22, p=0.2) did 2 not significantly correlate with proximal coronary artery plaque volume. Structure and function In comparison to non- and positively remodelled segments, negatively remodelled segments had a higher stiffness index (67±16 vs. 33±5 and 38±8 respectively; p<0.02). A significant degree of preservation of vasodilatation to 10"6 M acetylcholine was evident in positively remodelled compared with negatively remodelled segments (p<0.05). Coronary blood flow increased with both substance P and sodium nitroprusside infusions (p<0.001), although coronary sinus plasma t-PA antigen and activity concentrations increased only during substance P infusion (p<0.006 for both). There was a significant inverse correlation between coronary artery plaque burden and the release of active t-PA (r=- 0.61, p=0.003).CONCLUSIONS: Pulse wave analysis may be a useful non-invasive surrogate marker for the extent of coronary atherosclerosis. Atherosclerotic risk factors and coronary plaque load are associated with impaired vasomotor and endogenous fibrinolytic function. Though plaque type was similar in remodelled types, negative remodelling was associated with more pronounced local vascular and endothelial dysfunction. These findings collectively suggest an important local interrelationship between coronary vascular structure and function that has implications for the pathophysiology of ischaemic heart disease

Children’s Exposure to Environmental Toxins: Socioeconomic Factors and Subsequent Effects on Mental Health and Function

The physical environment in which children live, including the air they breathe and the water they drink, has a profound influence on their development. While children need many chemicals and nutrients to physically grow and develop normally, others, such as those deemed environmental toxins (e.g. pesticides, lead, mercury, and illicit substances) act instead as a threat to healthy development. These chemicals may have highly toxic effects, and while they are a threat to all individuals, they affect infants and children most severely. In order to provide an introduction to the issue of toxin exposure and mental health outcomes, to highlight the relevant evidence-based research, and to build a foundation for policy change, we present the following brief review of the literature

EXPLORING PERCEPTIONS OF ANTI-RACISM INTERVENTIONS AND POSSIBLE CORRELATES

Although there is a large body of research on anti-racism interventions, little research has been done on participant perceptions of anti-racism interventions or the relationship between certain perceptions and other factors. This study addresses perceptions of anti-racism interventions among college students and how perceptions relate to willingness to attend interventions, aspects of religiousness, identification with all of humanity, and factors such as gender and race. The sample includes 69 undergraduate students, all of whom self-identified as Christian. Results indicate that perceptions were generally positive. It was found that reported importance of interventions, agreement with reasons for positive attitudes, and willingness to attend interventions were all positively related to each other. Reported importance of interventions was also positively related to organizational religiousness, private religious practices, and intrinsic religious orientation, while willingness was only related to intrinsic religious orientation. These results suggest a link between positive perceptions and willingness to attend interventions, as well as a distinction between measures of religiousness and their implications for perceptions and behavior. These results suggest a need for further research on how perceptions of interventions impact their effectiveness and the specific factors that lead to specific perceptions