7,442 research outputs found
Systems, interactions and macrotheory
A significant proportion of early HCI research was guided by one very clear vision: that the existing theory base in psychology and cognitive science could be developed to yield engineering tools for use in the interdisciplinary context of HCI design. While interface technologies and heuristic methods for behavioral evaluation have rapidly advanced in both capability and breadth of application, progress toward deeper theory has been modest, and some now believe it to be unnecessary. A case is presented for developing new forms of theory, based around generic “systems of interactors.” An overlapping, layered structure of macro- and microtheories could then serve an explanatory role, and could also bind together contributions from the different disciplines. Novel routes to formalizing and applying such theories provide a host of interesting and tractable problems for future basic research in HCI
Preparation Methods for Quantitative Electron Probe X-Ray Microanalysis of Rat Exocrine Pancreas: A Review
Pancreatic acinar cells are thought to secrete a fluid containing digestive enzymes and electrolytes and use e,g, calcium as a second messenger upon stimulation, Together with their pronounced morphological polarity, they provide a model system to study the effect of different preparation methods for quantitative biological electron probe X-ray microanalysis (EPXMA) of ultrathin sections, Several preparation methods i,e,, freeze-drying and plastic-embedding, freeze-substitution (2 days) and freeze-drying of ultrathin cryosections have been applied to examine the retention of sodium, magnesium, phosphorus, sulfur, (chlorine), potassium and calcium in subcellular compartments (basal cytoplasm, apical cytoplasm, mitochondria and zymogen granules), In freeze-substituted samples the phosphorus, potassium and sulfur concentrations were 2-3 times lower in all compartments compared to freeze-dried, plastic-embedded samples, Intracellular potassium-to-sodium ratios obtained on frozen substituted and frozen-dried, plastic-embedded samples were considerably lower than for cryosections, Element gradients between adjacent organelles were large in frozen-dried cryosections, smaller in frozen-dried plastic-embedded samples and insignificant in frozen-substituted samples
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The Fourth-Century AD Expansion of the Graeco-Roman Settlement of Karanis (Kom Aushim) in the Northern Fayum*
The Graeco-Roman town of Karanis, founded during the Ptolemaic Period in the north-eastern Fayum in the third century bc and long thought to have been abandoned in the third century ad actually saw a substantial expansion during the fourth century AD. With the creation of an 3 extension towards the west and the expansion of the eastern part, the town grew in both directions. We argue that this expansion may be related to a sudden rise of the water level in Lake Moeris (Lake Qarun), perhaps linked to a catastrophic dam breach in the eastern part of the Fayum, and the subsequent relocation of the inhabitants of the low-lying settlements north and east of the lake
Phylogeny and Origin of Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency Mutations in Indonesia
The aim of this study is to analyze the relationship between the types of G6PD mutations found in Indonesia and the relationships of mutations found in Indonesia to those found in other countries. We summarize the distribution of G6PDs in West Indonesia and East Indonesia. Moreover, we use bioinformatics methods to construct phylogenetic trees and compare the sequences containing the regions amplifi ed by the commonly used PCR primer pairs. Previous work has shown that Mediterranean G6PD and Chinese CoimbraG6PDare distributed in West Indonesia, whilst G6PD mutations in East Indonesia are Jammu/ViangchanG6PD and Chinese Gaohe G6PD. G6PD Jammu/Viangchan was mostly distributed in Flores Island, East Indonesia along with G6PDGaohe. We constructed phylogenetic trees using the G6PD sequences from various regions in Indonesia and other countries. It appears from phylogenetic trees and percentages of identity that FloresIndonesian G6PD defi ciency (Jammu/Viangchan G6PD, originating in India) is 92.5% identical to the G6PD defi ciency of Chinese origin (GaoheG6PD). It was interesting to note that the genetic region containing the Javanese Indonesian G6PD defi ciency (MediterraneanG6PD, fi rst found in Italy) located in the western parts of Indonesia is closely related (99% identity) to the Chinese G6PD defi ciency(Coimbra G6PD). We concludethat G6PD mutations in West Indonesia are closely related to G6PD mutations from China. G6PD mutations in East Indonesia are also closely related to G6PD mutations from India and China, but more distantly, and to different types to those in West Indonesia. A prediction of protein structure was carried out which allowed visualization of the locations of mutation on the three dimensional structure of G6PD. Key words: G6PD, phylogeny, origin, genetic mutation
Six Years of ScoX-1 Monitoring with BeppoSAX Wide Field Cameras
We performed a systematic analysis of 54 Wide Field Camera (WFC) observations
of ScoX-1 available in the BeppoSAX public archive. Observations span over the
six years of BeppoSAX mission lifetime and include 690 hr of data. We searched
for shifts and shape changes of the Z pattern in the color-color diagrams. We
find that the Z pattern occupies most of the time the same locus in the
color-color diagram. There are however a few exceptions, which are discussed in
detail.Comment: 4 Pages, 4 figures. To appear in Proc. of the BeppoSAX Symposium:
"The Restless High-Energy Universe", E.P.J. van den Heuvel, J.J.M. in 't
Zand, and R.A.M.J. Wijers (Eds
Progress in Element Analysis on a High-Voltage Electron Microscope
X-Ray microprobe (XMA) and electron energy-loss (EELS) spectrometers have been installed on the high-voltage electron microscope (HVEM). The probe size has been measured and background reduction is in progress for XMA and EELS as are improvements in electron optics for EELS and sensitivity measurements.
XMA is currently useful for qualitative analysis and has been used by several investigators from our laboratory and outside laboratories. However, EELS background levels are still too high for meaningful results to be obtained. Standards suitable for biological specimens are being measured, and a library for quantitative analysis is being compiled
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