"Cloud" health-care workers.

Certain bacteria dispersed by health-care workers can cause hospital infections. Asymptomatic health-care workers colonized rectally, vaginally, or on the skin with group A streptococci have caused outbreaks of surgical site infection by airborne dispersal. Outbreaks have been associated with skin colonization or viral upper respiratory tract infection in a phenomenon of airborne dispersal of Staphylococcus aureus called the "cloud" phenomenon. This review summarizes the data supporting the existence of cloud health-care workers

The Influence of the Degree of Heterogeneity on the Elastic Properties of Random Sphere Packings

The macroscopic mechanical properties of colloidal particle gels strongly depend on the local arrangement of the powder particles. Experiments have shown that more heterogeneous microstructures exhibit up to one order of magnitude higher elastic properties than their more homogeneous counterparts at equal volume fraction. In this paper, packings of spherical particles are used as model structures to computationally investigate the elastic properties of coagulated particle gels as a function of their degree of heterogeneity. The discrete element model comprises a linear elastic contact law, particle bonding and damping. The simulation parameters were calibrated using a homogeneous and a heterogeneous microstructure originating from earlier Brownian dynamics simulations. A systematic study of the elastic properties as a function of the degree of heterogeneity was performed using two sets of microstructures obtained from Brownian dynamics simulation and from the void expansion method. Both sets cover a broad and to a large extent overlapping range of degrees of heterogeneity. The simulations have shown that the elastic properties as a function of the degree of heterogeneity are independent of the structure generation algorithm and that the relation between the shear modulus and the degree of heterogeneity can be well described by a power law. This suggests the presence of a critical degree of heterogeneity and, therefore, a phase transition between a phase with finite and one with zero elastic properties.Comment: 8 pages, 6 figures; Granular Matter (published online: 11. February 2012

Observation of vortex-nucleated magnetization reversal in individual ferromagnetic nanotubes

The reversal of a uniform axial magnetization in a ferromagnetic nanotube (FNT) has been predicted to nucleate and propagate through vortex domains forming at the ends. In dynamic cantilever magnetometry measurements of individual FNTs, we identify the entry of these vortices as a function of applied magnetic field and show that they mark the nucleation of magnetization reversal. We find that the entry field depends sensitively on the angle between the end surface of the FNT and the applied field. Micromagnetic simulations substantiate the experimental results and highlight the importance of the ends in determining the reversal process. The control over end vortex formation enabled by our findings is promising for the production of FNTs with tailored reversal properties.Comment: 20 pages, 13 figure

Assessment of processing technologies which may improve the nutritional composition of dairy products – Overview of progress

Among consumers there is a growing demand for food products with a natural nutritional-physiological advantage over comparable conventional products. As part of an EU funded project, ALP is examining the possible impact of processing on nutritionally valuable milk components, using the example of conjugated linoleic acids (CLA). The extent to which processing influences the CLA content of the end product was determined by literature research and own investigations of organic and conventional butter. Furthermore, new chemical, sensory-based and bio crystallization methods were evaluated by ALP and the University of Kassel to determine the oxidation stability of butter. In a further step the storage stability of CLA enriched and conventional butter was examined and the different methods will be compared. As a third objective a process for low-input CLA enrichment of milk fat (with a focus on alpine butter) has been developed. Since the process selected for the work is a physical enrichment process, it is accepted by international organic farming and food groups. Among the many benefits ascribed to CLA, it is believed to be an effective agent against cancer. The demand for foods with properties that promote human health is growing. The dairy industry has the opportunity to meet this demand by developing new dairy products with a nutritional-physiological function for the functional food market

Alternate proof of the Rowe-Rosensteel proposition and seniority conservation

For a system with three identical nucleons in a single-$j$ shell, the states can be written as the angular momentum coupling of a nucleon pair and the odd nucleon. The overlaps between these non-orthonormal states form a matrix which coincides with the one derived by Rowe and Rosensteel [Phys. Rev. Lett. {\bf 87}, 172501 (2001)]. The propositions they state are related to the eigenvalue problems of the matrix and dimensions of the associated subspaces. In this work, the propositions will be proven from the symmetric properties of the $6j$ symbols. Algebraic expressions for the dimension of the states, eigenenergies as well as conditions for conservation of seniority can be derived from the matrix.Comment: 9 pages, no figur

Imaging magnetic vortex configurations in ferromagnetic nanotubes

We image the remnant magnetization configurations of CoFeB and permalloy nanotubes (NTs) using x-ray magnetic circular dichroism photo-emission electron microscopy. The images provide direct evidence for flux-closure configurations, including a global vortex state, in which magnetization points circumferentially around the NT axis. Furthermore, micromagnetic simulations predict and measurements confirm that vortex states can be programmed as the equilibrium remnant magnetization configurations by reducing the NT aspect ratio.Comment: 14 pages, 4 figures, link to supplementary informatio

Distinct and shared gene expression for human innate versus adaptive helper lymphoid cells

Innate lymphoid cells (ILCs) are the latest identified innate immune cell family. Given their similarity in transcription factor expression and cytokine secretion profiles, ILCs have been considered as the innate phenocopy of CD4 Th cells. Here, we explored the transcriptome of circulating human ILC subsets as opposed to CD4 Th cell subsets. We describe transcriptomic differences between total ILCs and total CD4 Th cells, as well as between paired innate and adaptive cell subsets (ILC1 vs. Th1; ILC2 vs. Th2; and ILC3 vs. Th17 cells). In particular, we observed differences in expression of genes involved in cell trafficking such as CCR1, CCR6 and CXCR3, innate activation and inhibitory functions, including CD119, 2B4, TIGIT, and CTLA-4, and neuropeptide receptors, such as VIPR2. Moreover, we report for the first time on distinct expression of long noncoding RNAs (lncRNAs) in innate vs. adaptive cells, arguing for a potential role of lncRNA in shaping human ILC biology. Altogether, our results point for unique, rather than redundant gene organization in ILCs compared to CD4 Th cells, in regard to kinetics, fine-tuning and spatial organization of the immune response