The hierarchical Tobit model: A case study in Bayesian computing

In this paper we discuss the potentials of a new Bayesian inference tool, called the Gibbs sampler, for the analysis of the censored regression or Tobit model. Tobit models have a wide range of applications in empirical sciences, like econometrics and biometrics. The estimation results of the simple Tobit model will be compared to a hierarchical Tobit model, and the Gibbs sampling approach to the related classical algorithm of expectation-maximisation (EM). The underlying botanical example of this paper is concerned with the censoring mechanism in plant reproduction and proposes the Bayesian Tobit model for the growth relationship between the reproductive part and the rest of the plant.     

Enterprise networks: The re-engineering of complex software systems

Today technology design can no longer be understood as a design process on a green site. Design and implementation of new technology are always dependent on existing technology and the way it is used by people. In this respect Software-Engineering has also changed to the characteristics of normal technology design taking into account existing computer systems. Experiences show that the conditions and needs of such Software-Reengineering projects are highly complex and differ in their special characteristics ranging from aspects of quality of existing system documentation to organizational structures of the computer departments concerned. The Task-Artifact Cycle presented here gives a suitable reengineering approach emphasizing both analysis and design in Software-Reengineering.     

Using and managing multiple passwords: A week to a view

Security policies are required that protect information from unauthorised access, and also respect challenges users face in creating, and particularly managing, increasing numbers of passwords. This paper investigates real password use in the context of daily life. It presents the results of an empirical study where participants completed a password diary over 7 days, followed by debrief interviews to gain further knowledge and understanding of user behaviour. The results reported relate to how many passwords are in use, the types of passwords participants created, the relationships between different passwords and to sensitive services, how participants retrieved their passwords and finally, the different strategies adopted by users in their management of passwords. The paper concludes by providing a high level set of password guidelines, along with suggestions for mechanisms to support creating, encoding, retrieving and executing multiple passwords.     

Effects of differences in office chair controls, seat and backrest angle design in relation to tasks

In this study the influence of chair characteristics on comfort, discomfort, adjustment time and seat interface pressure is investigated during VDU and non-VDU tasks: The two investigated office chairs, both designed according to European and Dutch standards are different regarding: 1) seat cushioning and shape, 2) backrest angle and 3) controls. Thirty subjects in total, both male and female, participated in two experiments: twenty in the first and ten in the second.Significant differences are found for ease of adjustment and adjustment time of controls, independent of the tasks. Related to tasks, a significant difference was found for the backrest range of motion. For non-VDU tasks a larger range of backrest motion was preferred by 70% of the subjects. The chair design differences were most clear for comfort and adjustment time of controls, followed by comfort of backrest angle. No differences are found between seat pan comfort and discomfort, first impressions and peak interface pressure.     

Problems with India ink skin markings

India ink skin markings allow consistently reproducible radiation field setups. The authors report a case in which a facial tattoo was applied with an injection, resulting in permanent "black eyes." The vaccination technique has not been associated with this complication.     

Value of bone marrow biopsy in the diagnosis of amyloidosis

Amyloid involvement of the bone marrow is not commonly diagnosed before necropsy. Paraffin sections of the trephine bone biopsy specimen are superior to marrow aspiration cell smears for the antemortem diagnosis. Thirteen cases of amyloidosis were diagnosed from the bone biopsy specimen during a ten-year period. Amyloid was detected in only two of the corresponding aspirates. Three morphologic patterns of marrow involvement were found: vascular, focal extravascular/perivascular, and diffuse. Five (38%) of the cases were associated with multiple myeloma. An abnormal immunoglobulin was detected in the serum or urine or both in ten of 11 cases when determined. Although the bone marrow may not be the best site for the diagnosis of amyloidosis, it should not be neglected and marrow biopsies taken for other diagnostic reasons may "incidentally" reveal amyloid. Amyloidosis should be included in the list of non-primary hematologic conditions of the bone marrow in which the trephine biopsy may prove useful for diagnosis.     

On‐line Quality Control of Coated Glass. On‐line Qualitätskontrolle von beschichtetem Glas

Properties of optical coatings (e.g. low‐e or solar control) can be described and controlled using transmittance, reflectance and sheet resistance measurements. Multiple in situ transmittance measurement points allow a quick response to adjust different coating processes (layer thickness and homogeneity). For the final characterization of the coated substrate ex situ transmittance, reflectance and sheet resistance measurements are used. Accurate and reproducible measurements in a combination with Reverse Engineering methods admit monitoring all layers and in this way detecting slight drifts.     

SK119, a Novel Shikonin Derivative,Leads to Apoptosis in Melanoma Cell Lines and Exhibits Synergistic Effects with Vemurafenib and Cobimetinib

Melanoma is a complex and heterogenous disease, displays the deadliest form of skin cancer, and accounts for approx. 80% of all skin cancer deaths. In this study, we reported on the synthesis and pharmacological effects of a novel shikonin derivative (SK119), which is active in a nano-molar range and exhibits several promising in vitro effects in different human melanoma cells. SK119 was synthesized from shikonin as part of our search for novel, promising shikonin derivatives. It was screened against a panel of melanoma and non-tumorigenic cell lines using XTT viability assays. Moreover, we studied its pharmacological effects using apoptosis and Western blot experiments. Finally, it was combined with current clinically used melanoma therapeutics. SK119 exhibited IC₅₀ values in a nano-molar range, induced apoptosis and led to a dose-dependent increase in the expression and protein phosphorylation of HSP27 and HSP90 in WM9 and MUG-Mel 2 cells. Combinatorial treatment, which is highly recommended in melanoma, revealed the synergistic effects of SK119 with vemurafenib and cobimetinib. SK119 treatment changed the expression levels of apoptosis genes and death receptor expression and exhibited synergistic effects with vemurafenib and cobimetinib in human melanoma cells. Further research indicates a promising potential in melanoma therapy.