The Journal of Microelectronic Research 2008

https://scholarworks.rit.edu/meec_archive/1016/thumbnail.jp

Synchrotron Mössbauer spectroscopy using high-speed shutters

A new method of performing Mössbauer spectroscopy using a fast shutter in combination with microfocused synchrotron radiation is demonstrated

The effects of old and recent migration waves in the distribution of HBB*S globin gene haplotypes

Abstract Sickle cell hemoglobin is the result of a mutation at the sixth amino acid position of the beta (β) globin chain. The HBB*S gene is in linkage disequilibrium with five main haplotypes in the β-globin-like gene cluster named according to their ethnic and geographic origins: Bantu (CAR), Benin (BEN), Senegal (SEN), Cameroon (CAM) and Arabian-Indian (ARAB). These haplotypes demonstrated that the sickle cell mutation arose independently at least five times in human history. The distribution of βS haplotypes among Brazilian populations showed a predominance of the CAR haplotype. American populations were clustered in two groups defined by CAR or BEN haplotype frequencies. This scenario is compatible with historical records about the slave trade in the Americas. When all world populations where the sickle cell gene occurs were analyzed, three clusters were disclosed based on CAR, BEN or ARAB haplotype predominance. These patterns may change in the next decades due to recent migrations waves. Since these haplotypes show different clinical characteristics, these recent migrations events raise the necessity to develop optimized public health programs for sickle cell disease screening and management

The effects of old and recent migration waves in the distribution of HBB*S globin gene haplotypes

Abstract Sickle cell hemoglobin is the result of a mutation at the sixth amino acid position of the beta (β) globin chain. The HBB*S gene is in linkage disequilibrium with five main haplotypes in the β-globin-like gene cluster named according to their ethnic and geographic origins: Bantu (CAR), Benin (BEN), Senegal (SEN), Cameroon (CAM) and Arabian-Indian (ARAB). These haplotypes demonstrated that the sickle cell mutation arose independently at least five times in human history. The distribution of βS haplotypes among Brazilian populations showed a predominance of the CAR haplotype. American populations were clustered in two groups defined by CAR or BEN haplotype frequencies. This scenario is compatible with historical records about the slave trade in the Americas. When all world populations where the sickle cell gene occurs were analyzed, three clusters were disclosed based on CAR, BEN or ARAB haplotype predominance. These patterns may change in the next decades due to recent migrations waves. Since these haplotypes show different clinical characteristics, these recent migrations events raise the necessity to develop optimized public health programs for sickle cell disease screening and management

Lightweight fast rotating Fermi chopper, proof of principle for a scalable array chopper

The concept of the Fermi chopper array based on small Fermi rotors is explored. The advantages of such an array would be very low stored kinetic energy even for very fast running large area choppers and emerging possibilities for new and very flexible focussing schemes. The work comprises the investigation of a drive concept with a small motor and the design of a precise phase control. Further the rotor mechanics (stress and deformation) at high rotation frequencies has been optimised by FE-calculations. A chopper concept is studied with a small high speed motor connected to the rotor by means of an elastic shaft. This concept is comparable to the model of the “de Laval” or “Jeffcott” rotor.The development from a first layout of the Fermi rotor to a prototype aiming at high running speeds up to 1000 Hz is described and results for transmission, blocking and pulse shapes obtained at the ESS test beamline are reported

Introduction of Contemporary Physics to Pre-university Education

This symposium discusses the modes and means for introduction of contemporary physics to pre-university level education illustrated by a few successful examples. Examples come from soft matter physics in liquid crystals and hydrogels and solid-state physics in superconductors. The role of analogies is discussed and illustrated in analogy between superconductors and particle physics. In addition, a development of a professional development programme that will bridge the gap to new knowledge for active in-service teachers is presented