Distributed Reactive XML

XML-centric models of computation have been proposed as an answer to the demand for interoperability, heterogeneity and openness in coordination models. We present a prototype implementation of an open XML-centric coordination middleware called Distributed Reactive XML. The middleware has as theoretical foundation a general distributed extensible process calculus inspired by the theory of Bigraphical Reactive Systems. The calculus is extensible just as XML is extensible, in that its signature and reaction rules are not fixed. It is distributed by allowing both the state of processes as well as the set of reaction rules to be distributed (or partly shared) between different clients. The calculus is implemented by representing process terms as XML documents stored in a value-oriented, peer-to-peer XML Store and reaction rules as XML transformations performed by the clients. The formalism does not require that only process terms are stored—inside process terms one may store application specific data as well. XML Store provides transparent sharing of process terms between all participating peers. Conflicts between concurrent reaction rules are handled by an optimistic concurrency control. The implementation thus provides an open XML-based coordination middleware with a formal foundation that encompasses both the shared data, processes and reaction rules.     

Immobilization of DNA hydrogel plugs in microfluidic channels

Acrylamide-modified DNA probes are immobilized in polycarbonate microfluidic channels via photopolymerization in a polyacrylamide matrix. The resulting polymeric, hydrogel plugs are porous under electrophoretic conditions and hybridize with fluorescently tagged complementary DNA. The double-stranded DNA can be chemically denatured, and the chip may be reused with a new analytical sample. Conditions for photopolymerization, hybridization, and denaturation are discussed. We also demonstrate the photopolymerization of plugs containing different DNA probe sequences in one microfluidic channel, thereby enabling the selective detection of multiple DNA targets in one electrophoretic pathway.     

Polymeric pH nanosensor with extended measurement range bearing octaarginine as cell penetrating peptide

A synthetic peptide octaarginine which mimics human immunodeficiency virus‐1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental pH‐sensitive fluorophores in a same nanoparticle. The authors believe that this triple fluorescent pH sensor provides a new tool to pH measurements that can have application in cellular uptake mechanism study and new nanomedicine design.Inspec keywords: polymers, chemical sensors, nanosensors, biomembrane transport, microorganisms, proteins, biomimetics, biosensors, molecular configurations, biochemistry, molecular biophysics, nanoparticles, nanomedicine, nanocomposites, dyes, optical sensors, spectrochemical analysis, nanofabrication, biomedical measurementOther keywords: polymeric pH nanosensor, extended measurement range, octaarginine, cell penetrating peptide, synthetic peptide, human immunodeficiency virus‐1 Tat protein mimicking, cell penetrating moiety, complemental pH‐sensitive fluorophore incorporation, nanoparticle, triple fluorescent pH sensor, pH measurement, cellular uptake mechanism study, nanomedicine design     

Allocation flexibility for agribusiness supply chains under market demand disruption

This paper develops a multi-commodity multi-period optimisation model to analyse market demand disruption risk in agribusiness supply chains. It investigates the role of allocation flexibility and the effectiveness of multiple risk management strategies for achieving allocation flexibility. A robust optimisation formulation is used to obtain risk-averse solutions for an objective combining expected profit and risk. Numerical results are presented for a real-life case study of Zespri’s kiwifruit supply chain. The results show that allocation flexibility is effective for mitigating market demand disruption risk. Three proposed risk management strategies, namely diversified demand market, backup demand market and flexible rerouting, improve both expected profit and risk measures. While diversified demand market and backup demand market strategies are equally important for all decision-makers, flexible rerouting is especially significant for less risk-averse decision-makers.     

Determining the imaging quality of intraocular lenses

This paper describes research work motivated by an innovative medical application: computer-assisted transbronchial biopsy. This project involves the registration, with no external localization device, of a preoperative three-dimensional (3-D) computed tomography (CT) scan of the thoracic cavity (showing a tumor that requires a needle biopsy), and an intraoperative endoscopic two-dimensional (2-D) image sequence, in order to provide assistance in transbronchial puncture of the tumor. Because of the specific difficulties resulting from the data being processed, a multilevel strategy was introduced. For each analysis level, the relevant information to process and the corresponding algorithms were defined. This multilevel strategy, thus, provides the best possible accuracy. Original image processing methods were elaborated, dealing with segmentation, registration and 3-D reconstruction of the bronchoscopic images. In particular, these methods involve adapted mathematical morphology tools, a "daemon-based" registration algorithm, and a model-based shape-from-shading algorithm. This pilot study presents the application of these algorithms to recorded bronchoscopic video sequences for five patients. The preliminary results presented here demonstrate that it is possible to precisely localize the endoscopic camera within the CT data coordinate system. The computer can thus synthesize in near real-time the CT-derived virtual view that corresponds to the actual endoscopic view.     

Comparison between beryllium and diamond-backing plates in diamond-anvil cells: application to single-crystal x-ray diffraction high-pressure data

A direct comparison between two complete intensity datasets, collected on the same sample loaded in two identical diamond-anvil pressure cells equipped, respectively, with beryllium and diamond-backing plates was performed. The results clearly demonstrate that the use of diamond-backing plates significantly improves the quality of crystal structure data. There is a decrease in the internal R factor for averaging, structure refinement agreement factors, and in the errors and uncertainties of the atomic coordinates, atomic displacement parameters, and individual bond lengths.     

Immunohistochemical and serological comparison of idiopathic and hepatitis C virus-associated forms of oral lichen planus

The oral form of the inflammatory disease lichen planus occurs spontaneously due to unknown aetiological factors. However, it has recently been observed to occur with increased frequency in patients infected with the hepatitis C virus. Because of the prominent role of adhesion molecules in immune cell interactions, we have compared the expression of these antigens in the hepatitis C virus-associated and idiopathic forms of the disease. The results show similar patterns of expression of very late activation antigen-4, lymphocyte function-associated antigen-3 and intercellular adhesion molecule-1, but relatively elevated levels of these antigens in oral lichen planus patients with no hepatitis C virus infection. In addition to differences in Langerhans cell distribution, serum levels of "soluble" intercellular adhesion molecule-1 as well as immunoglobulin G were significantly increased in the hepatitis C virus-associated group. These findings show that there are some differences in the lesional and systemic immune reactivities of the two types of oral lichen planus which may be related to possibly distinct pathogenic mechanisms.     

Proton transfer in the mechanism of triosephosphate isomerase

Triosephosphate isomerase (TIM) catalyzes the reversible interconversion of dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (GAP), with Glu-165 removing the pro-R proton from C1 of DHAP and neutral His-95 polarizing the carbonyl group of the substrate. During the TIM reaction, approximately 2% of the pro-R tritium from C1 of DHAP is conserved and appears at C2 of GAP [Nickbarg, E. B., and Knowles, J. R. (1988) Biochemistry 27, 5939]. In the "classical" mechanism, 98% of the pro-R tritium exchanges with solvent from Glu-165 at the intermediate state and the remaining 2% is transferred by Glu-165 to C2 of the same substrate molecule. This intramolecular transfer of tritium is therefore predicted to be independent of DHAP concentration. On the basis of NMR detection of a strong hydrogen bond between Glu-165 and the 1-OH of an analogue of the enediol intermediate [Harris, T. K., Abeygunawardana, C., and Mildvan, A. S. (1997) Biochemistry 36, 14661], we have suggested a "criss-cross" mechanism for TIM in which Glu-165 transfers a proton from C1 of DHAP to O2 of the enediol, and subsequently from O1 of the enediol to C2 of the product GAP. Since the pro-R proton is transferred to O2 instead of C2 in the criss-cross mechanism, no intramolecular transfer of label from substrate to product would be expected to occur. However, intermolecular transfer of label could occur if the label exchanges from O2 into a group on the protein and is transferred to GAP in subsequent turnovers. The extent of intermolecular tritium transfer in the criss-cross mechanism would be predicted to be dependent on DHAP concentration. The extent of tritium transfer was studied as a function of initial DHAP concentration using DHAP highly tritiated at the pro-R position. At 50% conversion to GAP, triphasic tritium transfer behavior was found. For phase 1, between 0.03 and 0.3 mM DHAP, a constant extent of tritium transfer of 1.19 +/- 0.03% occurred. For phase 2, between 0.3 and 1.0 mM DHAP, the extent of transfer progressively increased as a function of DHAP concentration to 2.17 +/- 0.15%. For phase 3, between 1.0 and 7.0 mM DHAP, the extent of transfer slightly decreased to 1.68 +/- 0.17%. In a direct test for intermolecular isotope transfer, doubly labeled [1(R)-D, 13C3]DHAP and 13C-depleted [1(R)-H,12C3]DHAP were synthesized, mixed in equal amounts, and incubated at 1 mM total DHAP with TIM, GAP dehydrogenase, NAD+, and arsenate until 50% conversion to 3-phosphoglycerate occurred. Electrospray ionization mass spectral analysis of the stable 3-phosphoglycerate product detected an extent of 1.4 +/- 0.4% of intramolecular D transfer from [13C3]DHAP to the 13C3 product, but no intermolecular transfer (相似文献   

Curriculum revision: reaching faculty consensus through the Nominal Group Technique

A fundamental concept to initiate change in the curriculum revision process is to overcome resistance to change and the boundaries of self-interest. Curriculum change cannot occur without an "unfreezing" of faculty values and interests. The Nominal Group Technique (NGT) was used to facilitate faculty identification of areas needing change in the undergraduate nursing curriculum. The process led to the generation of numerous independent ideas in which all faculty participated. The revised curriculum which resulted from the NGT process has had full and enthusiastic support of the faculty.     

A more diversified America: state and local population changes, 1990-1997

Recently, the U.S. Bureau of the Census released state and county population estimates with age, gender, race and Hispanic origin detail for 1990-1997. These estimates illustrate the changing demographics of the United States. The 1997 state population estimates show that both Texas and Georgia experienced notable population growth since 1990. Texas replaced New York as the second largest state; Georgia bumped North Carolina from the list of top 10 most populous states to become the state with the 10th largest population. In both Texas and Georgia, migration flows have contributed to the population change. Texas is one of the most popular "intended states of residence" for international migrants, many coming from Latin American countries. On the other hand, Georgia's growth has largely been influenced by "rustbelt" to "sunbelt" domestic migration. At the county level, the largest total population increases again occurred in western and southern states. Population estimates for Asian and Pacific Islanders show that this population remained concentrated in the West in 1997. Similarly, the Hispanic population is primarily concentrated in southwestern states. However, as the Asian and Pacific Islander and Hispanic populations continue to grow, there is spillover into other regions, primarily the larger metropolitan areas in the South, including Washington, DC, and Atlanta, GA. The population projections produced by the Census Bureau indicate that racial and ethnic diversity will continue to increase in the United States well into the next century.