Asynchronous nuclear division cycles in multinucleated cells

Synchronous mitosis is common in multinucleated cells. We analyzed a unique asynchronous nuclear division cycle in a multinucleated filamentous fungus, Ashbya gossypii. Nuclear pedigree analysis and observation of GFP-labeled spindle pole bodies demonstrated that neighboring nuclei in A. gossypii cells are in different cell cycle stages despite close physical proximity. Neighboring nuclei did not differ significantly in their patterns of cyclin protein localization such that both G1 and mitotic cyclins were present regardless of cell cycle stage, suggesting that the complete destruction of cyclins is not occurring in this system. Indeed, the expression of mitotic cyclin lacking NH(2)-terminal destruction box sequences did not block cell cycle progression. Cells lacking AgSic1p, a predicted cyclin-dependent kinase (CDK) inhibitor, however, showed aberrant multipolar spindles and fragmented nuclei that are indicative of flawed mitoses. We hypothesize that the continuous cytoplasm in these cells promoted the evolution of a nuclear division cycle in which CDK inhibitors primarily control CDK activity rather than oscillating mitotic cyclin proteins

Hard water and old food. The freshwater reservoir effect in radiocarbon dating of food residues on pottery

This paper discusses the problem of the freshwater reservoir effect in the radiocarbon dating of different sample materials, in particular food crusts on pottery. Charred food residue can be used to directly date of the use of the pottery. However, this material is highly complex, which can lead to various dating errors. V članku predstavljamo problem sladkovodnega ‘rezervoar učinka’ pri radiokarbonskem datiranju različnih materialov, še posebno zoglenelih ostankov hrane na lončenini. Ti se lahko uporabijo za neposredno datiranje rabe keramičnih posod. Ker je njihova sestava zelo kompleksna, lahko pride do napak pri datiranju

Creation of Poseidon's world: adventures of the Aegean board game

In Ancient Greece, water was the way people got around. Before anyone would leave on a journey that involved the sea, they would give the Greek god Poseidon his sacrifices for fear that he would be upset and wreck their travels. He was the god of the sea, making him one of the most important gods in the Olympic pantheon. In speech-language pathology, board games are regularly used to incorporate therapy and to keep the client involved. In this project, a journey across Greece and the incorporation of therapeutic techniques are combined to create a board game that would be informative and entertaining to use in a therapy session while educating children about Ancient Greece.Honors CollegeThesis (B.?

The effects on hue resulting from black overprinting in halftone reproductions

A type of black printer that only existed in theory is now being applied in the printing industry. The process which makes use of this black printer is known as gray-component replacement. Developed from the extension of the undercolor removal process, the use of gray-component replacement in printing halftone reproductions is said to result in numerous technical and cost benefits. When used to the maximum, the process eliminates one of the three process color inks in a given unit area and prints black ink from highlight to shadow. A problem can result from the use of this process as it applies a greater amount of an opaque black ink in combination with selectively transparent colored inks. Where this black ink overprints one or more of the three colored inks there will be an increase in unwanted absorption and a decrease in the wanted absorption. The result of such overprinting will be the alteration of the reflectance curve of the reproduction as compared to the original with the result being a shift in hue. An experiment was performed to demonstrate the principles. Several tint patches were printed with the only difference between each patch being the location of black ink overprinting within the tint. It could be seen by visual analysis that a hue shift did occur. Sample tint patches were analyzed by means of a spectrophotometer to objectively describe the visual results

Modeling Basic Aspects of Cyber-Physical Systems

Designing novel cyber-physical systems entails significant, costly physical experimentation. Simulation tools can enable the virtualization of experiments. Unfortunately, current tools have shortcomings that limit their utility for virtual experimentation. Language research can be especially helpful in addressing many of these problems. As a first step in this direction, we consider the question of determining what language features are needed to model cyber-physical systems. Using a series of elementary examples of cyber-physical systems, we reflect on the extent to which a small, experimental domain-specific formalism called Acumen suffices for this purpose.Comment: Presented at DSLRob 2012 (arXiv:cs/1302.5082

A Modular and Statically Typed Effectful Stack for Custom Graph Traversals

Programmers often have to implement custom graph traversals by hand as either there are no suitable text-book algorithms for their tasks, or their problems are too complex for a pure querying language that lacks modularity or static typing. Our new Scala-based graph traversal language uses an effectful stack that adapts monads and type classes. Arbitrary graph effect computations and graph processing rules can be defined and composed in a modular and statically typed way. Custom graph traversals become expressible in a concise notation, run both in-memory and on graph databases, and also allow for parallelization. We evaluate the usability of our approach by detecting occurences of an anti-pattern in a Java source code archive. Our approach outperforms the well-known Gremlin approach due to parallelization

Dynamics of Multiple Nuclei in Ashbya gossypii Hyphae Depend on the Control of Cytoplasmic Microtubules Length by Bik1, Kip2, Kip3, and Not on a Capture/Shrinkage Mechanism

The multinucleate growth mode of A. gossypii has resulted in a unique control of cytoplasmic MT dynamics. Our analyses of MT +tips behavior and cMT–cell cortex interactions show the necessity of A. gossypii to produce very long cMTs for nuclear migration to compensate the lack of MT capture/shrinkage mechanisms important in budding yeast

Employing polyhedral methods to optimize stencils on FPGAs with stencil-specific caches, data reuse, and wide data bursts

It is well known that to accelerate stencil codes on CPUs or GPUs and to exploit hardware caches and their lines optimizers must find spatial and temporal locality of array accesses to harvest data-reuse opportunities. On FPGAs there is the burden that there are no built-in caches (or only pre-built hardware descriptions for cache blocks that are inefficient for stencil codes). But this paper demonstrates that this lack is also a chance as polyhedral methods can be used to generate stencil-specific cache-structures of the right sizes on the FPGA and to fill and flush them efficiently with wide bursts during stencil execution. The paper shows how to derive the appropriate directives and code restructurings from stencil codes so that the FPGA compiler generates fast stencil hardware. Switching on our optimization improves the runtime of a set of 10 stencils by between 43x and 156x