--To date, not enough attention has been paid to issues surrounding the description and enforcement of policies for controlling Grid resources. These policies define the permitted or desired usage scenario(s) allowed by resource providers, virtual organizations, or even the governing body for an entire Grid. Most existing Grid systems have either "in-spirit" usage policies with no actual enforcement (e.g., all resource providers are assumed to contribute in kind), or have implicit resource usage policies whose intent can only be manifested by examining the ad-hoc policy enforcement. Moreover, systems that do define some resource usage policies typically consider only CPU resources, without mentioning other Grid resources such as disk and bandwidth. Unless sufficient resource usage policies and enforcement mechanisms are created, resource providers will be increasingly reluctant to participate in Grids out of fear that their local resources will be overrun. In this paper, we identify the requirements for a resource usage policy language, and then propose an event-centric model by which to implement these policies. We describe the language structure, its implementation on top of the XML access control language XACML and a policy service that processes the language. Because decisions based on this type of policy typically require information from outside the security context of a single Grid request, we extend XACML for general timer-based and event-centric processing necessary to enforce such Grid resource usage policies. We evaluate our prototype implementation on a Grid consisting of three data repositories by showing that a usage policy-controlled Grid environment can be achieved with only minimal overhead.

No abstract

Drugs with poor biopharmaceutical performance are the main obstacle to the development and design of medicinal preparations. The anisotropic surface chemistry of different surfaces on the crystal influences its physical and chemical properties, such as solubility, tableting, etc. In this study, the antisolvent crystallization and rapid-cooling crystallization were carried out to tune the crystal habits of ticagrelor (TICA) form II. Different crystal habits of ticagrelor (TICA) form II (TICA-A, TICA-B, TICA-C, TICA-D, and TICA-E) were prepared and evaluated for solubility. The single-crystal diffraction (SXRD) indicated that TICA form II belongs to the triclinic P1 space group with four TICA molecules in the asymmetric unit. The TICA molecules are generated through intermolecular hydrogen bonds along the (010) direction, forming an infinite molecular chain, which are further stacked by hydrogen bonds between hydroxyethoxy side chains, forming molecular circles composed of six TICA molecules along bc directions. Thus, in the case of TICA form II, hydrogen bonds drive growth along one axis (b-axis), which results in the formation of mostly needle-shape crystals. Morphology and face indexation reveals that (001), (010) and (01-1) are the main crystal planes. Powder diffractions showed that five habits have the same crystal structure and different relative intensity of diffraction peak. The solubility of the obtained crystals showed the crystal habits affect their solubility. This work is helpful for studying the mechanism of crystal habit modification and its effect on solubility.Crystals 2019, 9, 556 2 of 15 such as crystal habit, polymorphism and reduction of the particle size [15][16][17][18][19][20]. There have been many studies demonstrating the effect of polymorphism on oral bioavailability and/or dissolution rate [21]. However, the dissolution rate not only differs for different polymorphisms, but also, for different crystal habits [22], which has received scant attention. Meanwhile, crystal habits also influence stability, flowability, suspension, packing, density, compaction, etc. [23][24][25][26][27]. Thus, optimizing crystal properties by modification of the crystal habit of a drug seems to offer an alternative approach to changing the bioavailability of drugs. The relative growth rate of each surface determines the overall shape of the crystal. The growth rate of the crystal surface will be controlled by a combination of structure-related factors, such as dislocations and intermolecular bonds, and by exterior factors such as solvents, rate of agitation, additives, temperature, etc. [28][29][30][31][32][33][34][35].This study aims to systematically investigate how crystal behavior affects the ticagrelor's solubility. TICA form II (TICA-II) with different crystal habits were prepared by controlling the crystallization process. To systematically investigate the relationship between crystal habit and orientation of the molecules of TICA form II in the crystal lattice, single crystals were obtained, and the cr...

Understanding the financial needs and preferences of retirees is critical for retirement income policy and product design. Today, Australian retirees are accumulating record levels of retirement savings in order to generate retirement income. Using qualitative and quantitative research methods, we find that retirees value leisure spending, but do not plan for long‐term health and care needs. Moreover, retirees value risk protection but are unwilling to forgo potential investment gains. The differing levels of importance that retirees attach to aspects of retirement, health, intergenerational planning and family dynamics suggest that retirement income products cannot be ‘one‐size‐fits‐all’.

Efficient allocations in common-pool resources cannot be accomplished when appropriators are selfish. In addition, we find that a system of a common-pool resource is locally unstable if there are four or more appropriators. Such instability most likely makes efficiency worse than that in the Nash equilibrium. These results indicate that equilibrium analyses might not capture the essence of the common-pool resource problem. They may also provide an answer to the unexplained pulsing behavior among appropriators and inefficiency observed in experiments.Keywords: Appropriation problem, best-response dynamics, common-pool resources, experiment, instability, Nash equilibrium, pulsing behavior Acknowledgement: We thank Professor James Walker for providing us with the individual data of the experiments in Walker et al. 1990. We also thank Y. Kamijo and the anonymous reviewers for their valuable comments that helped to improve the manuscript.