Performance of a high concentration Er/sup 3+/-doped alumino silicate fiber amplifier

We report the gain, noise figure, output saturation power, and conversion efficiency of a highly concentrated Er/sup 3+/-doped alumino silicate fiber amplifier. We obtain a gain per unit length of 1.0 dB/cm, which corresponds to the highest gain per unit length obtained in an Er/sup 3+/-doped fiber amplifier. The pump power threshold ranges from 2 to 5 mW, depending on the fiber length.     

Installing a color system: The people considerations

The introduction of low-price color systems, both quality control and color formulation, has brought affordability and practicality to the medium and small plastics companies. While color systems today are faster, cheaper, more accurate, easier to use than ever before, they are not that much more successful at doing what they were designed to do than they were 25 years ago. The pitfalls of start-up and implementation and the people problems have changed very little and are still a major factor in determining the degree of success. This paper discusses the ramifications of who is chosen to implement the system, what their charter is, and the resources that they are given. Factors to be considered and creating the right environment when implementing a color system are discussed. Some suggestions for planning a successful start-up and installation are given.     

Growth kinetics of silver chloride precipitation in a Na2O-B2O3 glass investigated by means of small-angle X-ray scattering and transmission electron microscopy

The kinetics of silver chloride cluster formation in a sodium borate glass heat treated isothermally at different temperatures above the glass transition temperature has been studied with small-angle X-ray scattering (SAXS). It is established that the size distributions of particle number and particle volume have bimodal shapes, i.e. the system of AgCl droplets consists of two populations with significantly different mean radii. The bimodality of the size distribution functions is confirmed by results of transmission electron microscopy (TEM) even if different techniques of sample preparation are used. The resolution limits of the TEM techniques applied amount to 2 nm and are comparable with the smallest particle diameters detectable by the SAXS method. The evolution of the size distributions is discussed in the framework of the theories of nucleation, growth and Ostwald ripening.     

Graded comprehensive cardiopulmonary exercise testing in the evaluation of dyspnea unexplained by routine evaluation

The evaluation of dyspnea is problematic when a cause is inapparent after initial diagnostic studies. We examined the results and role of cardiopulmonary exercise testing (CPET) in 50 patients with a mean 23 months of dyspnea and normal FEV1 and FVC. The CPET studies were interpreted by a panel and a consensus reached. Subsequent tests ordered by the primary physician were reviewed, and a final diagnosis was agreed on by the panel. Seven of 50 patients had cardiac limitation, 17 of 50 had pulmonary limitation, 14 of 50 had obesity and/or deconditioning, 1 of 50 had gastroesophageal reflux, and 16 of 50 had either psychogenic dyspnea or no identifiable disease. Five patients had more than one clinical diagnosis accounting for 55 diagnoses in the 50 patients. Those with a normal CPET had a higher VO2max and O2 pulse than those with cardiac disease, deconditioning, or hyperactive airways disease (HAD) (p < 0.05). Electrocardiographic changes identified cardiac disease while studies demonstrating ventilatory limitation identified a pulmonary process. In 24, deconditioning could not be distinguished from cardiac limitation. Of these, 14 responded to exercise training and/or weight loss, whereas 3 had cardiac disease, 7 had HAD, and 4 had psychogenic dyspnea (4 had more than one clinical diagnosis). In the 13 patients with normal CPET results, one had gastroesophageal reflux, two had HAD, four had psychogenic dyspnea, and six had no identifiable disease. We conclude that a diagnosis can be made in most patients with chronic dyspnea; however, further studies including bronchoprovocation are often required. Cardiopulmonary exercise testing is useful in identifying a cardiac or pulmonary process, but it is insensitive in distinguishing cardiac disease from deconditioning.     

Geographic epidemiology of gonorrhea in Baltimore, Maryland, using a geographic information system

Ws/Ws rats are deficient in both mucosal- and connective tissue-type mast cells. To study the role of mast cells in active anaphylaxis, changes in vascular permeability in the trachea upon intravenous antigen challenge with Evans blue dye were examined in Ws/Ws, heterogenic Ws/+, and normal +/ + rats sensitized with the nematode Nippostrongylus brasiliensis. Antigen challenge resulted in fatal anaphylactic shock in some +/+ and Ws/+ rats, but not in Ws/Ws rats. Marked dye leakage developed within 30 min in the trachea of +/+ and Ws/+ rats, while Ws/Ws rats showed no substantial increases in the levels of vascular permeability. Ex vivo stimulation of sensitized lung fragments from +/+ animals with specific antigen induced significant releases of histamine and leukotriene (LT) C4, while sensitized Ws/Ws rat-lung fragments did not. In Ws/Ws rats, levels of nematode-specific IgE, IgG1 and IgG2a antibodies as well as levels of lung eosinophilia were not significantly different from those in +/+ rats. These results show that mast cell-deficient Ws/Ws rats fail to develop active anaphylaxis, and this is mediated probably by the lack of mast cell-derived mediators required for initiation of the reaction.     

Electron spin resonance of DNA irradiated with a heavy-ion beam ([16]O[8+]): evidence for damage to the deoxyribose phosphate backbone

A major problem in the intensive care unit nowadays is the development of multiple organ dysfunction syndrome (MODS), a cumulative sequence of progressive deterioration of organ functions. While the pathogenic pathways of MODS remain to be elucidated, it is assumed that cells of the host defence system, especially the macrophages, are altered in their function. During the development of MODS it is assumed that macrophages are overactivated and that an exaggerated inflammatory response may contribute to its pathogenesis. In order to gain insight into the alterations of the functional status of the macrophage during the development of MODS, a series of macrophage functions was measured in the subsequent phases of zymosan induced generalized inflammation in mice. Male C57BL/6 mice received a single dose of zymosan intraperitoneally and groups of animals were killed after 2, 5, 8, and 12 days. Peritoneal macrophages were collected for in vitro assessment of the ADCC, the production of superoxide (O2-) and nitric oxide (NO), and complement mediated phagocytosis and intracellular killing of Staphylococcus aureus. A single intraperitoneal injection with zymosan resulted in a three-phase illness. During the third phase the animals developed MODS-like symptoms. Peritoneal cells from control animals produced very low to non-detectable amounts of O2- and NO, and the cytotoxic activity was also low. During the development of MODS, from day 7 onwards, the ability to produce O2- and NO2- became strongly elevated, as did the cytotoxic activity. These findings are in parallel with the development of MODS whereas the phagocytic and killing capacity remained essentially unaltered. The changes found could be detrimental for the organism, thus possibly contributing to the onset and development of MODS.     

Autonomy and gender: Some questions for therapists.

Discusses the nature of autonomy and explores how autonomy as a therapeutic goal relates to clinical practice and the conduct of psychotherapy. Autonomy has been defined as the power to determine one's own best interests, and it has been criticized for promoting selfishness and reflecting upper-class values and gender bias. It is suggested that issues of autonomy are involved in the process of psychotherapy as well as its aim. In therapy, there is a dynamic tension between the principle of autonomy, the right of clients to determine their own interests, and the principle of beneficence, the therapist's obligation to protect the client's welfare. Whether autonomy is an appropriate ideal in psychotherapy for women or for men is considered. Feminist theorists have criticized aspects of masculine autonomy, contrasting it with feminine relatedness; however, the idealization of relatedness is questioned. It is concluded that the present conceptualizations of autonomy do not fully encompass the complexity of human interaction. It is argued that (a) autonomy and relatedness are not essential aspects of male and female nature but depend on power and status and (b) without social change, autonomy may not be a realistic goal of therapy for women. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of random vaccine response on the vaccination coverage required to prevent epidemics

The response people have to vaccination varies because their immune systems differ and vaccine failures occur. Here we consider the effect that a random response, independent for each vaccinee, has on the vaccination coverage required to prevent epidemics in a large community. For a community of uniformly mixing individuals an explicit expression is found for the critical vaccination coverage (CVC) and the effect of the vaccine response is determined entirely by the mean E(AB), where A and B, respectively, reflect the infectivity and susceptibility of a vaccinated individual. This result shows that the usual concept of vaccine efficacy, which focuses on the amount of protection the vaccine provides the vaccinee against infection, is not adequate to describe the requirements for preventing epidemics when vaccination affect infectivity. The estimation of E(AB) poses a problem because A and B refer to the vaccine response of the same individual. Similar results are found when there are different types of individual, but now the mean E(AB) may differ between types. However, for a community made up of households it is shown that the CVC also depends on other characteristics of the vaccine response distribution. In practice this means that estimating a single measure of vaccine effectiveness is generally not enough to determine the CVC. For a specific community of households it is found that the vaccination coverage required to prevent epidemics decreases as the variation in the vaccine response increases.