Prednisolone disposition in steroid-dependent asthmatics

A 40-mg intravenous dose of prednisolone was given as prednisolone phosphate to seven severe steroid-dependent asthmatics and to 13 healthy volunteers to determine if the large prednisone requirements of these patients were a function of the disease, cellular response, or rapid clearance of prednisolone. Plasma concentrations of prednisolone, prednisone, and cortisol were determined by high-performance liquid chromatography over an 8-hr test period. Circulating eosinophil concentrations were monitored concurrently. The apparent half-lifes of prednisolone in the asthmatics and normals were 3.33 +/- 0.71 and 3.25 +/- 0.58 hr (mean +/- SD). The apparent plasma clearances of prednisolone were 201 +/- 54 and 198 +/- 38 ml/min/1.73 m2 and the apparent volumes of distribution were 50.8 +/- 11.7 and 53.5 +/- 13.5 L/1.73 m2 for the asthmatic and normal groups, respectively. When the concentration-dependent binding of prednisolone to plasma protein was examined, no differences in the apparent clearances of unbound drug were found between the two groups. The eosinopenic response to prednisolone was similar in the steroid-dependent asthmatics and healthy normal volunteers. These studies indicate that binding, distribution, and clearance of prednisolone are not responsible for the large prednisone requirement of some steroid-dependent asthmatics. Differences in steroid-receptor sensitivity or in severity or pathophysiology of the disease state more likely account for the need for large prednisone dosages in these patients.     

Evaporation of crude oil at sea

A simple model for describing the simultaneous evaporation and spreading of oil spills at sea has been developed and tested. A previously reported theory was used for calculating the aerodynamic part of the evaporation process. Here, the thermodynamic part, i.e. the oil characterization and the weathering processes, is described in detail. By comparison with the results of laboratory evaporation experiments and sea trials the model is shown to work quite adequately. Also, the influence of the mixing of oil into the water column, e.g. due to wave action, is shown to be small enough to be neglected. The spreading model was purposely kept as simple as possible, in view of the uncertain influences of wave action and emulsion formation. The velocity of the edge of the oil slick is prescribed and a critical thickness beyond which the slick stops spreading is introduced. The latter turns out to have a significant influence on the rate of evaporation. Examples of crude evaporation are given and the influence of temperature and wind velocity is investigated.     

The counseling center: A mirror of institutional size.

Investigated the relationship between counseling center orientation and size of institution in which the center is located. 19 census-type variables were subjected to principal components analysis, and 4 estimated factors scores were derived for a population of 157 counseling centers. Results indicate that institutional size predicts counseling center orientation but that a more qualitative evaluation of counseling centers requires other than census-type data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some properties of inn films prepared by reactive evaporation

Some optical and electrical properties of degenerate InN films prepared by a reactive evaporation technique are presented. Thermal stability of these easily dissociated samples is discussed and evidence is presented indicating that the partial pressure of atomic nitrogen rather than diatomic nitrogen is a more fundamental parameter for describing thermal equilibrium. This has important implications for the growth of all group III-nitrides.     

Use of multiwavelength transmission spectroscopy for the characterization of Cryptosporidium parvum oocysts: quantitative interpretation

Combined scattering and absorption properties of suspended particles can be obtained as a function of wavelength by measuring the complete ultraviolet-visible (UV-vis) spectrum. This research reports on the quantitative interpretation of measured UV-vis spectra of Cryptosporidium parvum oocyst suspensions obtained from several commercial sources and evaluated using two different purification techniques. The reproducibility of the measured spectral data was assessed, and the quantitative interpretation of the oocyst spectra in terms of the particle size and the chemical composition of the particles are reported herein. The interpretation model of the spectra is based on light scattering theory, spectral deconvolution techniques, and on the approximation of the wavelength-dependent optical properties of the basic constituents of living organisms. A characteristic set of optical properties for C. parvum oocysts has been determined as a function of wavelength and used for the quantitative interpretation of UV-vis spectra. The results from the spectral deconvolution show quantitative differences among oocyst preparations. These results represent the first step in establishing a set of critical parameters (e.g., oocyst size and chemical composition) necessary for the detection and identification of C. parvum oocysts in water using spectroscopy.     

Co-deposition of aluminide and silicide coatings on γ-TiAl by pack cementation process

Thermochemical analyses were carried out for a series of pack powder mixtures for deposition of aluminide and for co-deposition of aluminide and silicide coatings on -TiAl by the pack cementation process. Based on the results obtained, experimental studies were undertaken to identify optimum pack powder mixtures for depositing adherent and coherent aluminide and silicide coatings. Pack powder mixtures activated by 2 wt% AlCl₃ was used to aluminise -TiAl at 1000°C. With proper control of pack compositions and coating conditions, an aluminide coating of TiAl₃ with a coherent structure free from microcracking was deposited on the substrate surface via inward diffusion of aluminium. The results of thermochemical calculations indicated that co-deposition of Al and Si is possible with CrCl₃ · 6H₂O and AlCl₃ activated pack powders containing elemental Al and Si as depositing sources. Experimental results obtained at 1100°C revealed that CrCl₃ · 6H₂O is not suitable for use as an activator for co-depositing aluminide and silicide coatings on -TiAl. It caused a significant degree of degradation instead of coating deposition to the substrate. However, adherent coatings with excellent structural integrity consisting of an outer TiSi₄ layer and an inner TiAl₃ layer were successfully co-deposited at 1100°C and 1000°C using pack powder mixtures activated by AlCl₃. IT is suggested that such coatings were formed via a sequential deposition mechanism through inward diffusion of aluminium and silicon. Discussion is presented on the issues that need to be considered to ensure the deposition of aluminide and silicide coatings with coherent structure free from microcracking on -TiAl by the pack cementation process.     

Cognitive and learning difficulties and how they affect access to IT systems

In October 2005, the IBM Human Ability and Accessibility Center and T.J. Watson Research Center hosted a symposium on “cognitive and learning difficulties and how they affect access to IT systems”. The central premise of the symposium was the recognition that cognitive and learning difficulties have a profound impact on a person’s ability to interact with information technology (IT) systems, but that little support is currently being offered by those systems. By bringing together internationally renowned experts from a variety of different, but complementary, research fields, the symposium aimed to provide a complete overview of the issues related to this topic. This paper summarises the discussions and findings of the symposium.     

Associative symmetry versus independent associations in the memory for object-location associations.

The formation of associations between objects and locations is a vital aspect of episodic memory. More specifically, remembering the location where one experienced an object and, vice versa, the object one encountered at a specific location are both important elements for the memory of an event. Whether episodic associations are holistic representations of individual components or whether there are unidirectional, separately modifiable connections between them has been investigated nearly exclusively using verbal stimuli. A preliminary conclusion concerning this controversy is that verbal associations are, at least, highly correlated (M. J. Kahana, 2002). This theoretical debate, which in the past has undergone a major empirical effort, is still of relevance for the concurrent global matching models of associative memory (S. E. Clark & S. D. Gronlund, 1996). The authors used variations of a novel object-location learning paradigm to complement the accumulated evidence regarding the nature of episodic associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Making the invisible visible: Fear and disclosure of sexual orientation at work.

Stigma theory was used to examine the fears underlying the disclosure of a gay identity at work. Using a national sample of 534 gay, lesbian, and bisexual employees, this study examined the antecedents that affect the degree of disclosure of a gay identity at work and, for those who had not disclosed, the factors that influence their fears about full disclosure. Employees reported less fear and more disclosure when they worked in a group that was perceived as supportive and sharing their stigma. Perceptions of past experience with sexual orientation discrimination were related to increased fears but to greater disclosure. For those who had not fully disclosed their stigma, the fears associated with disclosure predicted job attitudes, psychological strain, work environment, and career outcomes. However, actual disclosure was unrelated to these variables. The utility of fear of disclosure for understanding processes underlying the disclosure of gay and other invisible stigmatized identities in the workplace is discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)