Using formalized temporal message-flow diagrams

Temporal message-flow diagrams (TMFDs), alternatively called sequence charts, interaction diagrams, event traces, or actor diagrams, are illustrations of a system's global message-passing activity over time, and a pictorial aid to understanding the system's behavior. They are widely used for requirements and documentation for network protocols and object-oriented applications. We present a general formalism for TMFDs, describe a suite of tools we have designed that employs this formalism, and present our experiences with these tools. The formalism and tools described serve to support and broaden the use of TMFDs in developing communicating systems.     

Program comprehension during software maintenance and evolution

Code cognition models examine how programmers understand program code. The authors survey the current knowledge in this area by comparing six program comprehension models: the Letovsky (1986) model; the Shneiderman and Mayer (1979) model; the Brooks (1983) model; Soloway, Adelson and Ehrlich's (1988) top-down model; Pennington's (1987) bottom-up model; and the integrated metamodel of von Mayrhauser and Vans (1994). While these general models can foster a complete understanding of a piece of code, they may not always apply to specialized tasks that more efficiently employ strategies geared toward partial understanding. We identify open questions, particularly considering the maintenance and evolution of large-scale code. These questions relate to the scalability of existing experimental results with small programs, the validity and credibility of results based on experimental procedures, and the challenges of data availability     

EXPERIMENTALLY-SIMULATED STYLOLITIC POROSITY IN CARBONATE ROCKS

An experimental program of stylolitic porosity development in stylolitic Atokan (Middle Pennsylvanian) limestones under simulated conditions of deep burial has shown that experimental dissolution preferentially occured and developed along existing styloties. The dissolution sequence was as follows: incipient pores following the traces of stylolites, grading into stylolitic lamellar pores, which enlarged eventually into non-fabric-selective channels. These stylolite-controlled conduits were surrounded by adjacent incipient-to-complete oomolds, enlarged oomolds, incipient-to-complete algal bioclast molds, enlarged biomolds, and halos of intercrystalline porosity to microporosity.
Trace element analysis (Mg, Sr, and Ca) of pore-fluid samples during early phases of experimental deep burial dissolution indicated that slightly less stable protions of carbonates enriched in Mg and Sr dissolved preferentially, as observed also in natural cases. Pyrolysis data indicate that stylolites concerntrated organic matter derived from inter-stylolite areas. This situation demonstrates the pressure-solution origin of stylolites.
Experimental stylolitic pore networks are similar in type, size, and geometry to natural stylolitic porosity. This preferential dissolution suggests that natural stylolites result from late (post pressure-solution dissolution, are not necessarily mechanically induced during stylolite formation as sometimes postulated, and act as effective conduits for secondary porosity generation in deeply-buried carbonate rocks     

插画设计

Von Glitschka为我们解释怎样直接用插画技术，来解决创建专业化标识中所遇到的视觉问题。     

The effect of the cyclin-dependent kinase inhibitor olomoucine on cell cycle kinetics

The effect of the cyclin-dependent (CDK) inhibitors olomoucine and roscovitine on cell kinetics was studied. To this end, nonsmall cell lung cancer (NSCLC) cell line MR65 and neuroblastoma cell line CHP-212 were pulse labeled with bromodeoxyuridine (BrdUrd) and chased in culture medium, to which various concentrations of olomoucine or roscovitine were added. A dose-dependent inhibition of the G1/S-phase and G2/ M-/G1 transitions was observed. Furthermore, S-phase progression was also inhibited in a dose-dependent manner. Similarly, roscovitine, another CDK inhibitor with a 10-fold higher efficiency for both CDK1 and CDK2 as compared to olomoucine, showed the same effects at a 10-fold lower concentration. At the highest tested doses both olomoucine (200 microM) and roscovitine (40 microM) induced a complete cell cycle block in both cell lines, paralleled by the appearance of apoptotic figures. In these cultures a decrease in CDK1 protein level was found as shown by Western blotting. Bivariate CDK1/DNA analysis confirmed these observations and showed that a subpopulation of cells with characteristics of apoptosis became CDK1 negative. The presented data suggest that cyclins and CDKs are involved at an important nodal point shared by pathways regulating cellular proliferation and apoptosis.     

A voltage reduction technique for battery-operated systems

Two techniques for voltage reduction are presented, both of which can significantly reduce the power consumption of digital CMOS circuits. The fixed reduction of voltage is applicable to small systems with a low initial consumption, however, the optimum voltage is not reached and the correct operation of the circuit is not guaranteed. The self-adjusted reduction of voltage is adapted to bigger digital systems. The correct operation of the digital circuit is guaranteed, and the supply voltage is near the optimum for the speed requirements. This technique is more versatile, accurate, and reliable than the fixed one     

Double sodium and potassium sulphates revealed by microprobe analysis in dried cervical mucus: a mid-cycle crystallographic index

The use of physical techniques such as scanning electron microscopy and microprobe analysis permits the analysis of valuable details of the structure of dried samples of mid-cycle cervical mucus during the period of maximum ferning. From a crystallographic point of view, particular attention was paid to the location, morphology and chemical composition of anisotropic organic sulphate microstructures. As distinct from the isotropic sodium chloride pattern described by Papanicolaou, these appear in a narrow period of time corresponding to the middle of the period of maximum ferning. Anisotropic microstructures were revealed to be tiny isolated crystals or polycrystalline aggregates composed of double salts of potassium and sodium. The potassium/sodium cation ratio, equal to 3/1, was constant in the best specimens. Using a simple polarizing microscope, the detection of anisotropic microstructures may be useful to determine the period of maximum fertility more accurately. In addition, experiments have been carried out in order to determine the relative importance of sulphate anisotropic structures as compared with the whole crystallized surface and to investigate precisely their transience after they appear.