Topology by Design in Magnetic nano-Materials: Artificial Spin Ice

Artificial Spin Ices are two dimensional arrays of magnetic, interacting nano-structures whose geometry can be chosen at will, and whose elementary degrees of freedom can be characterized directly. They were introduced at first to study frustration in a controllable setting, to mimic the behavior of spin ice rare earth pyrochlores, but at more useful temperature and field ranges and with direct characterization, and to provide practical implementation to celebrated, exactly solvable models of statistical mechanics previously devised to gain an understanding of degenerate ensembles with residual entropy. With the evolution of nano--fabrication and of experimental protocols it is now possible to characterize the material in real-time, real-space, and to realize virtually any geometry, for direct control over the collective dynamics. This has recently opened a path toward the deliberate design of novel, exotic states, not found in natural materials, and often characterized by topological properties. Without any pretense of exhaustiveness, we will provide an introduction to the material, the early works, and then, by reporting on more recent results, we will proceed to describe the new direction, which includes the design of desired topological states and their implications to kinetics.Comment: 29 pages, 13 figures, 116 references, Book Chapte

An international survey of bacterial contamination and householders' knowledge, attitudes and perceptions of hygiene

This prospective, multinational study was conducted in 20 homes in eight cities or regions in different countries to determine the level of microbiological contamination of common surfaces and items, and investigate the attitudes and perceptions of householders towards cleaning and hygiene. Environmental Health Practitioners took eight standardised swabs in each home. The swabs were cultured for a range of micro-organisms. Householders ( n=160) were also interviewed regarding their cleaning habits and perceptions of hygiene. Overall, 28% of surfaces or items tested in the study had ‘moderate bacterial growth’ or ‘heavy bacterial growth’. Kitchen cloths were the most contaminated items, with 86% having moderate bacterial growth or heavy bacterial growth; kitchen taps were the second most contaminated items, with 52% having moderate bacterial growth or heavy bacterial growth. High proportions (&gt;50%) of kitchen cloths contained coliforms, Enterobacteriaceae and Pseudomonas spp. The visual appearance of surfaces and items frequently (30%) did not correspond to their level of contamination with micro-organisms. The majority of householders (65%) cleaned to make the house ‘look clean, smell nice and remove germs’; however, householders’ perceptions of the cleanliness of their homes frequently did not correspond to microbiological reality. In conclusion, further research and education are needed regarding hygiene in the home. </jats:p

The survival of influenza A(H1N1)pdm09 virus on 4 household surfaces.

We investigated the survival of a pandemic strain of influenza A H1N1 on a variety of common household surfaces where multiple samples were taken from 4 types of common household fomite at 7 time points. Results showed that influenza A H1N1sw virus particles remained infectious for 48 hours on a wooden surface, for 24 hours on stainless steel and plastic surfaces, and for 8 hours on a cloth surface, although virus recovery from the cloth may have been suboptimal. Our results suggest that pandemic influenza A H1N1 can survive on common household fomites for extended periods of time, and that good hand hygiene and regular disinfection of commonly touched surfaces should be practiced during the influenza season to help reduce transmission

The survival of influenza A(H1N1)pdm09 virus on 4 household surfaces.

We investigated the survival of a pandemic strain of influenza A H1N1 on a variety of common household surfaces where multiple samples were taken from 4 types of common household fomite at 7 time points. Results showed that influenza A H1N1sw virus particles remained infectious for 48 hours on a wooden surface, for 24 hours on stainless steel and plastic surfaces, and for 8 hours on a cloth surface, although virus recovery from the cloth may have been suboptimal. Our results suggest that pandemic influenza A H1N1 can survive on common household fomites for extended periods of time, and that good hand hygiene and regular disinfection of commonly touched surfaces should be practiced during the influenza season to help reduce transmission