Drosophila myb is required for the G2/M transition and maintenance of diploidy

The myb proto-oncogenes are thought to have a role in the cell division cycle. We have examined this possibility by genetic analysis in Drosophila melanogaster, which possesses a single myb gene. We have described previously two temperature-sensitive, recessive lethal mutants in Drosophila myb (Dm myb). The phenotypes of these mutants revealed a requirement for myb in diverse cellular lineages throughout the course of Drosophila development. We now report a cellular explanation for these findings by showing that Dm myb is required for both mitosis and prevention of endoreduplication in wing cells. Myb apparently acts at or near the time of the G2/M transition. The two mutant alleles of Dm myb produce the same cellular phenotype, although the responsible mutations are located in different functional domains of the gene product. The mutant phenotype can be partially suppressed by ectopic expression of either cdc2 or string, two genes that are known to promote the transition from G2 to M. We conclude that Dm myb is required for completion of cell division and may serve two independent functions: promotion of mitosis, on the one hand, and prevention of endoreduplication when cells are arrested in G2, on the other.     

Bone mineral density in patients undergoing bone marrow transplantation for myeloid malignancies

Hitherto the biology of proteolysis in prokaryotes, particularly in archaea, is only poorly understood. We have used the tri-peptide vinyl sulfone inhibitor carboxybenzyl-leucyl-leucyl-leucine vinyl sulfone (Z-L3VS) to study the in vivo function of proteasomes in Thermoplasma acidophilum. Z-L3VS is a potent inhibitor of the Thermoplasma proteasome and is capable of modifying 75 to 80% of the proteasomal beta-subunits in cell cultures. Inhibition of proteasomes has only marginal effects under normal growth conditions. Under heat shock conditions, however, the effects of proteasome inhibition are much more severe, to the extent of complete cell growth arrest. These data suggest that other proteolytic systems may exist that can compensate for the loss of proteasome function in T. acidophilum.     

An automated framework for verifying or refuting trace properties of extended finite state machines

Model checkers and interactive proof assistants are both used in the assurance of critical systems. Where theorem proving involves the use of axioms and inference rules to mathematically prove defined properties, model checkers can be used to provide concrete counterexamples to refute them. Thus, the two techniques can be thought of as complementary, and it is helpful to use both in tandem to take advantage of their respective strengths. However, this requires us to translate our system model and our desired properties between the two tools which is a time-consuming and error prone process if done manually. The key contribution of this work is a set of automated tools to translate between the Isabelle/HOL proof assistant and the Symbolic Analysis Laboratory (SAL) model checker. We focus on systems specified as extended finite state machines (EFSMs) and on properties specified in linear temporal logic (LTL). We present our representations in the two tools and demonstrate the applicability of our system with respect to an academic example and two realistic case studies. This is a significant contribution to broadening the applicability of these formal approaches, since it allows two powerful verification tools to be easily used in tandem without the risk of human error.

     

An empirical test of the structure, process, and outcome quality paradigm using resident-based, nursing facility assessment data

This study distinguishes between organizational characteristics, regarded as exogenous structural indicators of quality, and those identified as endogenous indicators of structural care (SC), and investigates the degree to which measures of SC vary by ownership mode (defined by four combinations of chain affiliation and profit status) for 142 certified and licensed nursing facilities (NFs) in a southern state. Structural care measures include: licensed and unlicensed staffing, licensed therapists, and case mix-adjusted direct care expenditures. In addition, seven (four process and three outcome) facility-level, risk-adjusted process, and outcome quality scales are developed from 39 resident-level quality indicators. A causal mode of NF quality arranged according to the structure, process and outcome paradigm is specified and estimated using path analysis. Organizational data derive from the 1991 Medicaid Cost Report; process and outcome quality measures were developed from the Minimum Data Set Plus Resident Assessment Instrument. Using the percentage of Medicaid and private pay residents as covariates, there was a significant overall multivariate effect due to ownership mode on the SC measures. Although there were several significant direct effects, the overall path model was unconfirmed. The multivariate results suggest that some organizational characteristics of structure quality may be more appropriately considered exogenous to causal quality models and therefore have indirect (versus direct) effects on process or outcome quality indicators. The path analysis implies that the structure-process-outcome paradigm may not accurately capture the way NF health care is delivered. Research which considers alternate NF quality paradigms needs to be done with samples that are more representative of national proportions of each ownership mode.     

Nonparametric item analyses of the Beck Depression Inventory: Evaluating gender item bias and response option weights.

Nonparametric item response models were used to investigate the psychometric properties of the Beck Depression Inventory in depressed outpatient (N?=?648) and nonpatient college (N?=?1,182) samples. The authors examined item bias between men and women as a function of severity of depression and distinguished group mean differences from item bias. They also assessed the appropriateness of the weights assigned to response option categories. In both depressed outpatient and nonpatient college samples, most items and options discriminated individuals differing in degree of depression, and little gender item bias existed between men and women. Estimated response option weights did, however, correspond more closely to a priori weights in the depressed outpatient sample than in the nonpatient college sample. The greatest amount of bias was observed in Item 14, assessing distortion of body image. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Related donor marrow transplant for chronic myeloid leukemia: patient characteristics predictive of outcome

This article presents health expectancy calculations from Bulgaria for 1976-1992. The calculations are based on mortality statistics and data from a national information system from the Expert Medical Commissions on Working Capacity about loss of working capacity. Following internationally accepted terminology, the most appropriate term for the health expectancies presented here is "occupational handicap-free life expectancy' (OHFLE). Life expectancies were calculated as partial life expectancies from ages 16 to 59. Health expectancy calculations followed Sullivan's cross-sectional method with age and sex specific prevalence data on occupational handicap. Around 1985 a three- to four-fold increase in these prevalences occurred. The distribution of occupational handicaps over sexes, age groups and severity levels, however, remained fairly constant. The results show a decrease both in partial life expectancy within the age range 16-59 and in OHFLE at the age of 16 for men. For women a more or less stable partial life expectancy and a decrease in OHFLE at the age of 16 was found around 1985. The introduction of more incentives for people who successfully registered probably caused the decrease around 1985. Major social changes may have acted as confounding factors for the fluctuations after 1985. On the other hand the findings may reflect real changes in population health due to an increasing incidence in some major disease categories. The nation-wide system for assessment and registration of health related working incapacity has proved a useful source for an attempt to calculate OHFLE. Given uncertainties about the population health underlying these changes in OHFLE, however, it is recommended that health interview and health examination surveys should be considered as alternative routes for achieving a more comprehensive picture of population health in Bulgaria.     

Three-dimensional nanometric sub-surface imaging of a silicon flip-chip using the two-photon optical beam induced current method

Two- and three-dimensional sub-surface optical beam induced current imaging of a silicon flip-chip is described and is illustrated by results corresponding to 166 nm lateral resolution and an axial performance capable of localising feature depths to around 100 nm accuracy. The experimental results are compared with theoretically modelled performance based on analytic expressions for the system point spread functions valid for high numerical apertures, and are interpreted using numerical geometric ray tracing calculations. Examples of depth-resolved feature profiling are presented and include depth cross-sections through a matrix of tungsten vias and a depth-resolved image of part of a poly-silicon wire.     

A distributed programming assistant

This paper describes an interactive programming environment within which proposed changes to a program are monitored to ensure that they do not introduce various common types of logical inconsistency. The environment, which is provided by a network of concurrent ‘experts’ dealing with various aspects of the program being developed, is designed to be convenient to work in and to impose few constraints on the programmer.     

Test method for measuring non-visible set-off from inks and lacquers on the food-contact surface of printed packaging materials

The main objective was to develop a technique to expose spots of invisible set-off of inks and lacquers on the food-contact surface of food-packaging materials. Set-off is the unintentional transfer of components of printing inks from the outer printed surface onto the food-contact surfaces. The target sensitivity was 20 µg cm^-2 and the technique should be capable of examining large areas of printed substrate for no more than 4% coverage by set-off. These requirements equate to an ability to detect a worst-case migration potential of less than 50 µg kg^-1. Other objectives were the industrial requirements that the equipment should be inexpensive, should be easy to use by existing personnel and should preferably be non-destructive with a clear criterion for pass or fail. The approaches investigated included chemical analysis of solvent extracts, Fourier-transform infrared spectroscopy and microbeam analytical techniques, but these were found to be cumbersome and had only limited success. The objectives were achieved using an optical approach to excite and observe luminescence from invisible set-off. In model experiments, resins were applied to different substrates (plastic, paper and cartonboard). For a given resin on a given material, the key to success was to maximize the discrimination between the luminescence from the resin and that from the substrate by selecting the optimal combination of exciting wavelength and viewing goggles with selective wavelength filters. The required level of detection (20 µg cm^-2) was achieved or exceeded for all ten resins tested on three different plastics. It was also achieved for two different papers and in all but four cases of the resins on three different cartonboards. Quantitation was achieved by the use of a calibration palette prepared using different quantities of resin spotted onto the relevant blank packaging material.