Mapping a quantitative trait locus involved in melanotic encapsulation of foreign bodies in the malaria vector, Anopheles gambiae

A Plasmodium-refractory strain of Anopheles gambiae melanotically encapsulates many species of Plasmodium, whereas wild-type mosquitoes are usually susceptible. This encapsulation trait can also be observed by studying the response of refractory and susceptible strains to intrathoracically injected CM-Sephadex beads. We report the results of broad-scale quantitative trait locus (QTL) mapping of the encapsulation trait using the bead model system. Interval mapping using the method of maximum likelihood identified one major QTL, Pen1. The 13.7-cM interval containing Pen1 was defined by marker AGH157 at 8E and AGH46 at 7A on 2R. Pen1 was associated with a maximum LOD score of 9.0 and accounted for 44% of the phenotypic variance in the distribution of phenotypes in the backcross. To test if this QTL is important for encapsulation of Plasmodium berghei, F2 progeny were infected with P. berghei and evaluated for degree of parasite encapsulation. For each of the two markers that define the interval containing Pen1, a significant difference of encapsulation was seen in progeny with at least one refractory allele in contrast with homozygous susceptible progeny. These results suggest that Pen1 is important for melanotic encapsulation of Plasmodium as well as beads.     

A shared genetic mechanism for melanotic encapsulation of CM-Sephadex beads and a malaria parasite, Plasmodium cynomolgi B, in the mosquito, Anopheles gambiae

Dialysis dose and malnutrition have a great impact on the clinical out come of chronic hemodialysis patients. The interrelationships between them, however, remain undefined. Thus, we performed a study to determine the effects of increasing the dialysis dose on serum albumin concentrations and mortality in hemodialysis patients. We examined urea kinetic modeling, biochemical nutritional indices, comorbid conditions, patient survival time, and annual mortality rate. Dialysis dose, measured by Kt/V, significantly increased from 1.3 +/- 0.3 in 1987 to 1.5 +/- 0.4 in 1990 and to 1.7 +/- 0.4 in 1993. Serum albumin level also increased from 3.8 +/- 0.4 g/dL in 1987 to 4.0 +/- 0.4 in 1990 and to 1.7 +/- 0.4 in 1993. In 1993, 76% of patients had Kt/V > or = 1.50 compared with 45% in 1990 and 28% in 1987, whereas 82% of patients had a serum albumin level > or 4.0 g/dL in 1993 compared with 58% in 1990 and 29% in 1987. Protein catabolic rate and hematocrit also increased from 1987 to 1993, but not serum cholesterol or triglyceride. The annual mortality rate declined from 16.1% in 1987 to 13.2% in 1990 and to 8.0% in 1993. The decrease in mortality appeared to be unrelated to differences in patient selection or comorbid conditions. Serum albumin levels, hematocrit, Kt/V, and protein catabolic rate were significantly related to patient survival after age, sex, and diabetic status had been adjusted. Furthermore, there was a positive correlation between Kt/Vs and serum albumin concentration (r = 0.216, P < 0.001). Thus it appears that increasing the dose of dialysis improves serum albumin levels and perhaps survival rate in hemodialysis patients as well.     

Der Umgang mit „second victims“ als organisationsethische Aufgabe

Background and purpose

Adverse events and medical errors can have severe consequences for patients (“first victims”), but also for the involved health care professionals (“second victims”). Don Berwick, former director of the Boston Institute for Healthcare Improvement (USA), highlighted the support for “second victims” as an “ethical issue”. But there is no clarity about what “ethical issue” implies. This article aims to clarify this question from the perspective of organizational ethics.

Method

Starting with data from the literature, challenges are described and evaluated from the perspective of organizational ethics.

Results

Evidence suggests that current approaches for supporting “second victims” are not sufficiently effective to help professionals to cope with the psychological consequences of adverse patient events and medical errors. This not only has negative consequences for the involved professionals, but can also put patient safety again at risk. In the light of these data, an organizational ethics approach is needed to comply with Don Berwick’s claim to consider the support of “second victims” as an “ethical issue”. This approach fosters the congruence of the organization’s values that are declared and those that are practiced. Its normative foundation is rooted in the organization’s duty of care both for the patients and for the employees.

Conclusions

Using organizational ethics it is possible to conceptualize and visualize the support for “second victims” as a binding component of the safety culture of the organization. It is translated into the organization’s obligation to raise the awareness for the phenomenon and to provide the resources necessary to deal effectively with it, e.?g., evidence-based ethical guidelines, standardized procedures, staff training, and low-threshold coaching programs.

     

Optimization of a plate with holes

We consider a simply supported plate with constant thickness, defined on an unknown multiply connected domain. We optimize its shape according to some given performance functional. Our method is of fixed domain type, easy to be implemented, based on a fictitious domain approach and the control variational method. The algorithm that we introduce is of gradient type and performs simultaneous topological and boundary variations. Numerical experiments are also included and show its efficiency.     

Anti-vibration Engineering in Internal Turning Using a Carbon Nanocomposite Damping Coating Produced by PECVD Process

Machining dynamic stability has been enhanced through a damping coating based on a novel carbon-based nanocomposite material. The coating was synthesized using a plasma enhanced chemical vapor deposition method, and deposited on to the round-shank boring bar used for internal turning and tested during machining. Comparisons between an uncoated and a coated boring bar were carried out at 0.25 mm and 0.5 mm depth of cut using a five times length to diameter ratio overhang, which are typical conditions known to generate detrimental mechanical vibrations. From sound pressure measurement it was found that the measured absolute sound level during process could be reduced by about 90% when using the tool coated with damping layer. Surface roughness measurements of the processed workpiece showed decreased Ra values from approximately 3-6 μm to less than 2 μm (and in 50% of the cases <1 μm) when comparing an uncoated standard tool with its coated counterpart. Moreover, it was found that the addition of an anti-vibration coating did not adversely affect other tool properties, such as rigidity and modularity.     

Water reuse for irrigation from waste water treatment plants with seasonal varied operation modes.

Irrigation periods are usually limited to vegetation periods. The quality requirements for treated wastewater for disposal and for reuse are different. The reuse of water for irrigation allows partly the reuse of the wastewater's nutrients (N and P). Outside the irrigation period the water must be treated for disposal, thus nutrient removal is often required in order to avoid detrimental effects on the receiving surface water body. Only wastewater treatment plants with different operation modes for different seasons can realise these requirements. The nitrification is the most sensitive biological process in the aerobic wastewater treatment process. At low water temperatures the nitrifying bacteria need several weeks to re-start full nitrification after periods without NH4-removal. Therefore it is necessary to develop options for waste water treatment plants which allow a fast re-start of the nitrification process. Based on theoretical considerations and computer simulations of the activated sludge treatment process, one possibility for implementing a wastewater treatment plant with different seasonal operation modes is evaluated.     

Proportional damping approximation using the energy gain and simultaneous perturbation stochastic approximation

The design of vector second-order linear systems for accurate proportional damping approximation is addressed. For this purpose an error system is defined using the difference between the generalized coordinates of the non-proportionally damped system and its proportionally damped approximation in modal space. The accuracy of the approximation is characterized using the energy gain of the error system and the design problem is formulated as selecting parameters of the non-proportionally damped system to ensure that this gain is sufficiently small. An efficient algorithm that combines linear matrix inequalities and simultaneous perturbation stochastic approximation is developed to solve the problem and examples of its application to tensegrity structures design are presented.