47 research outputs found
Visualization of Anthropometric Measures of Workers in Computer 3D Modeling of Work Place
In this work, 3D visualization of a work place by means of a computer-made 3D-machine
model and computer animation of a worker have been performed. By visualization
of 3D characters in inverse kinematic and dynamic relation with the operating part
of a machine, the biomechanic characteristics of workerâs body have been determined.
The dimensions of a machine have been determined by an inspection of technical documentation
as well as by direct measurements and recordings of the machine by camera.
On the basis of measured body height of workers all relevant anthropometric measures
have been determined by a computer program developed by the authors. By knowing the
anthropometric measures, the vision fields and the scope zones while forming work
places, exact postures of workers while performing technological procedures were determined.
The minimal and maximal rotation angles and the translation of upper and
lower arm which are basis for the analysis of worker burdening were analyzed. The dimensions
of the seized space of a body are obtained by computer anthropometric analysis
of movement, e.g. range of arms, position of legs, head, back. The influence of forming
of a work place on correct postures of workers during work has been reconsidered
and thus the consumption of energy and fatigue can be reduced to a minimum
Visualization of Anthropometric Measures of Workers in Computer 3D Modeling of Work Place
In this work, 3D visualization of a work place by means of a computer-made 3D-machine
model and computer animation of a worker have been performed. By visualization
of 3D characters in inverse kinematic and dynamic relation with the operating part
of a machine, the biomechanic characteristics of workerâs body have been determined.
The dimensions of a machine have been determined by an inspection of technical documentation
as well as by direct measurements and recordings of the machine by camera.
On the basis of measured body height of workers all relevant anthropometric measures
have been determined by a computer program developed by the authors. By knowing the
anthropometric measures, the vision fields and the scope zones while forming work
places, exact postures of workers while performing technological procedures were determined.
The minimal and maximal rotation angles and the translation of upper and
lower arm which are basis for the analysis of worker burdening were analyzed. The dimensions
of the seized space of a body are obtained by computer anthropometric analysis
of movement, e.g. range of arms, position of legs, head, back. The influence of forming
of a work place on correct postures of workers during work has been reconsidered
and thus the consumption of energy and fatigue can be reduced to a minimum
The Hungarian Monetary Policy Model
March 2011 marked the introduction of the Magyar Nemzeti Bank's Monetary Policy Model (MPM), representing a paradigm shift in both macroeconomic projection and monetary policy decision support. In contrast to previous conditional projections, the MPM provides an endogenous definition of both the projected policy rate and the projected exchange rate. Given the forward-looking nature of the model, expectations of economic agents play a key role in the monetary transmission process; therefore, the future achievement of the inflation target is guaranteed by the projected path of the interest rate over the forecast horizon. In this paper, we discuss the underlying structure and logic behind the MPM, describe the key behavioural equations and examine how the channels of monetary transmission appear in the model. In addition, we present the empirical validation process in detail from calibration, through Bayesian estimation and discussion of the economic properties of the model to the historical projection exercise. Finally, we discuss the main challenges we faced during the first year of application
Efficiency of Spermatogonial Dedifferentiation during Aging
Adult stem cells are critical for tissue homeostasis; therefore, the mechanisms utilized to maintain an adequate stem cell pool are important for the survival of an individual. In Drosophila, one mechanism utilized to replace lost germline stem cells (GSCs) is dedifferentiation of early progenitor cells. However, the average number of male GSCs decreases with age, suggesting that stem cell replacement may become compromised in older flies.Using a temperature sensitive allelic combination of Stat92E to control dedifferentiation, we found that germline dedifferentiation is remarkably efficient in older males; somatic cells are also effectively replaced. Surprisingly, although the number of somatic cyst cells also declines with age, the proliferation rate of early somatic cells, including cyst stem cells (CySCs) increases.These data indicate that defects in spermatogonial dedifferentiation are not likely to contribute significantly to an aging-related decline in GSCs. In addition, our findings highlight differences in the ways GSCs and CySCs age. Strategies to initiate or enhance the ability of endogenous, differentiating progenitor cells to replace lost stem cells could provide a powerful and novel strategy for maintaining tissue homeostasis and an alternative to tissue replacement therapy in older individuals
Molecular Evolution of Phosphoprotein Phosphatases in Drosophila
Phosphoprotein phosphatases (PPP), these ancient and important regulatory enzymes are present in all eukaryotic organisms. Based on the genome sequences of 12 Drosophila species we traced the evolution of the PPP catalytic subunits and noted a substantial expansion of the gene family. We concluded that the 18â22 PPP genes of Drosophilidae were generated from a core set of 8 indispensable phosphatases that are present in most of the insects. Retropositons followed by tandem gene duplications extended the phosphatase repertoire, and sporadic gene losses contributed to the species specific variations in the PPP complement. During the course of these studies we identified 5, up till now uncharacterized phosphatase retrogenes: PpY+, PpD5+, PpD6+, Pp4+, and Pp6+ which are found only in some ancient Drosophila. We demonstrated that all of these new PPP genes exhibit a distinct male specific expression. In addition to the changes in gene numbers, the intron-exon structure and the chromosomal localization of several PPP genes was also altered during evolution. The GâC content of the coding regions decreased when a gene moved into the heterochromatic region of chromosome Y. Thus the PPP enzymes exemplify the various types of dynamic rearrangements that accompany the molecular evolution of a gene family in Drosophilidae
Distinct Effects of p19 RNA Silencing Suppressor on Small RNA Mediated Pathways in Plants
RNA silencing is one of the main defense mechanisms employed by plants to fight viruses. In change, viruses have evolved silencing suppressor proteins to neutralize antiviral silencing. Since the endogenous and antiviral functions of RNA silencing pathway rely on common components, it was suggested that viral suppressors interfere with endogenous silencing pathway contributing to viral symptom development. In this work, we aimed to understand the effects of the tombusviral p19 suppressor on endogenous and antiviral silencing during genuine virus infection. We showed that ectopically expressed p19 sequesters endogenous small RNAs (sRNAs) in the absence, but not in the presence of virus infection. Our presented data question the generalized model in which the sequestration of endogenous sRNAs by the viral suppressor contributes to the viral symptom development. We further showed that p19 preferentially binds the perfectly paired ds-viral small interfering RNAs (vsiRNAs) but does not select based on their sequence or the type of the 5â nucleotide. Finally, co-immunoprecipitation of sRNAs with AGO1 or AGO2 from virus-infected plants revealed that p19 specifically impairs vsiRNA loading into AGO1 but not AGO2. Our findings, coupled with the fact that p19-expressing wild type Cymbidium ringspot virus (CymRSV) overcomes the Nicotiana benthamiana silencing based defense killing the host, suggest that AGO1 is the main effector of antiviral silencing in this host-virus combination