The deterministic and reliable singlemode fiber integration with spatial solitons through ultratight needs in photorefractives have been demonstrated. Efficient electro-optic beam handling was allowed where the fiber carried the information sequence and also delivered the photorefractively active control beam that configured the circuitry.
We previously described synthetic peptides of 19-21 amino acid residues, homologous to the C-termini of fibrinogen Fib340 and Fib420, from the β-chain (Cβ), the extended αE chain (CαE) and near the end of the γ-chain (preCγ) which elicited attachment (haptotactic) responses from mesenchymal cells. We named these haptotactic peptides -Haptides. The effects of Haptides on fibrin clot formation was evaluated and their possible effects on platelet aggregation was examd. The Haptides Cβ, CαE and preCγ, (2-10 μM) increased fibrin clot turbidity and also decreased thrombin-induced clotting time. Higher concns. (>120 μM of Cβ or preCγ) induced fibrinogen pptn. even without thrombin. These ppts. exhibited different ultrastructure from thrombin-induced fibrin by scanning and transmission microscopy. C-terminal peptides of the other fibrinogen chains exerted no such effects. Sepharose beads covalently coated with either whole fibrinogen or Haptides (SB-Fib or SB-Haptide) highly adsorbed free FITCHaptides. In aq. soln., Haptides formed nano-particles with av. size of ∼150nm in diam. We suggest that such pos. charged aggregates could serve to nucleate and accelerate fibrin gel formation. These results also indicate that Cβ and preCγ sequences within fibrin(ogen) participate in the docking and condensation of fibrin(ogen) during its assembly into a fibrin clot. By contrast, Haptides up to 100μM did not bind to platelets, and had no effect on platelet aggregation. Our findings highlight the roles of the C-terminal sequences of the β and γ chains in fibrin(ogen) polymn. as well as in cell attachment. [on SciFinder(R)]
A new and facile method is presented to evaluate w/o/w emulsions contg. fluorescent markers by flow cytometry. Flow cytometry allows simultaneous measurement of w/o/w emulsion droplets "marked" with a fluorescent marker or "blank" without the need for complicated sample prepn. The yield of prepn. of the w/o/w emulsion and the release rate of the fluorescent marker FITC-BSA were investigated by this new method. The release fraction (after 24 h) of FITC-BSA from the w/o/w emulsion decreased with increasing concn. of FITC-BSA inside the internal phase, just like the release fraction of NaCl as marker from the w/o/w emulsion. Flow cytometry results show that the yield and release behavior in w/o/w emulsions are in agreement with results reported by more complicated methods. [on SciFinder(R)]
This article addresses the issue of how international relations theories and experts do at forecasting Israeli–Palestinian relations. A group of academics who study the Middle East were brought together to set forth their logic and arguments concerning possible future scenarios of Israeli–Palestinian relations. The article reports on a ‘rule-based’ computational model built upon the reasoning of these experts. Sensitivity analysis of the model is summarized, and four empirical tests of the model are reported. Relations between Middle East states, externally generated existential threats to Israel, and domestic structural factors such as coalition politics in Israel emerge as driving forces in the sensitivity analysis. Further examination shows that the model is in theoretical harmony with scholars who have employed two-level games and has some similarity to realist explanations and frameworks emphasizing public opinion. Model tests reveal relatively solid results: comparisons with other forecasts generally favor this model, while both the cases of the Labor Party coming to power in Israel and a change in Jordanian behavior after the death of King Hussein lend further support to the model presented here. Finally, when the scholars who served as the expert group to produce these forecasts were asked to reflect back on the process, they exhibited the same rationalizations that have been found in other expertbased forecasts, even though the results of the forecasts were more favorable than many such forecasts.
Progress in the study of a new class of chemically bound compounds of noble-gas atoms is reviewed. The focus is on rare-gas molecules of the form HNgY, where Ng is a noble-gas atom and Y is an electronegative group, prepared by photolysis of HY in the rare-gas matrix. Other related types of new molecules of noble-gas atoms are discussed as well. Topics discussed in this review include: (a) The nature of bonding and the energetic stability of the compounds. (b) The vibrational spectroscopy of the molecules, and its role in identification of the species. (c) The mechanism and dynamics of photochemical formation of HNgY in the matrix, and the pathways for thermal and infrared (IR)-induced decomposition. Specifically, attention is given to the issue of ``direct'' formation following photolysis of HY versus ``delayed'' formation involving H atom diffusion. (d) Molecules of the lighter rare gases Ar, Ne, and He, focusing on the experimentally prepared HArF and on theoretical predictions suggesting the existence of other molecules. (e) The most-recently discovered photochemically induced insertion compounds of Ng into hydrocarbons, such as HXeCCH. (f) Clusters of HNgY with other molecules. The possible existence of neat aggregates and crystals of HNgY The reviewed state-of-the-art suggests this field is at an early stage of development with major open questions bearing on the surprising properties of the molecules and on the formation mechanisms. These are part of the challenge for the future.
The autoresonance phenomenon allows excitation of a classical, oscillatory nonlinear system to high energies by using a weak, chirped frequency forcing. Ladder climbing is its counterpart in quantum mechanics. Here, for the first time to our knowledge, conditions for the transition from the quantum to the classical regimes are outlined. The similarities and differences between the two approaches are presented.
The increasing number and expansion of trading blocs is an important dimension of the contemporary international economy. This study examines the effects of such trading blocs on third parties and on the multilateral trading system. It is argued that trading blocs have negative economic effects on economic sectors in non-members' states. These sectors urge their governments to take political action vis-à-vis the trading bloc. Governments have several policy choices on their menu, and the attractiveness of these policies is determined by domestic and international incentives and constraints. I argue that filing a complaint in the GATT/WTO is an attractive and effective policy tool in the hands of third parties' governments. Thus, I hypothesize that the existence, deepening, and widening of trading blocs result in an increase in the number of complaints filed against their members in the multilateral trading system. I examine these propositions in the context of three important trading blocs—namely, the EU, NAFTA, and Mercosur—in the period 1948–2000. To test these hypotheses a time-series cross-section count model is performed. Controlling for conventional alternative explanations, the empirical analysis supports the theoretical framework.
Viral delivery of the therapeutic gene bone morphogenetic protein-2 (BMP-2) is a promising approach for bone regeneration. The human parvovirus adeno-associated virus (AAV) type 2 is considered one of the most encouraging viral vector systems because of its high transduction rates and biosafety ratings. Bone morphogenetic protein-2 is a highly potent osteoinductive protein, which induces bone formation in vivo and osteogenic differentiation in vitro. The exogenous regulation of BMP-2 expression in bone-regenerating sites is required to control BMP-2 protein secretion, thus promoting safe and controlled bone formation and regeneration. We have therefore constructed a dual-construct vector for the recombinant AAV (rAAV)-based recombinant human BMP-2 (rhBMP-2) gene delivery system, which is regulated by the tetracycline-sensitive promoter (TetON). Each vector was encapsidated separately, yielding two recombinant viruses. We evaluated the efficiency of rAAV-hBMP-2 to induce bone formation in ectopic and orthotopic sites. Doxycycline (Dox), an analogue of tetracycline, was orally administered to mice via their drinking water to induce rhBMP-2 expression. Bone formation was measured using quantitative imaging-microcomputerized tomography and cooled charge-coupled device imaging-to detect osteogenic activity at the cellular level, detecting osteocalcin expression. The rAAV-hBMP-2-treated mice that were given Dox demonstrated bone formation in both in vivo models compared to none in mice prevented from receiving Dox. Thus, the Tet-regulated rAAV-hBMP-2 vector is an effective means of induction and regulation of bone regeneration and repair.
