All-optical switching due to state-filling in quantum dots

We report all-optical switching due to state-filling in quantum dots (QDs) within a Mach-Zehnder Interferometric (MZI) switch. The MZI was fabricated using InGaAsP/InP waveguides containing a single layer of InAs/InP QDs. A 1530-1570 nm probe beam is switched by optical excitation of one MZI-arm from the top. By exciting below the InGaAsP bandgap, we prove that the refractive index nonlinearity is only due to the QDs. The switching efficiency is 2 rad/(microW absorbed power). Probe wavelength insensitivity was obtained using a broad distribution of QDs.Comment: 12 page

A proposed architecture and method of operation for improving the protection of privacy and confidentiality in disease registers

BACKGROUND: Disease registers aim to collect information about all instances of a disease or condition in a defined population of individuals. Traditionally methods of operating disease registers have required that notifications of cases be identified by unique identifiers such as social security number or national identification number, or by ensembles of non-unique identifying data items, such as name, sex and date of birth. However, growing concern over the privacy and confidentiality aspects of disease registers may hinder their future operation. Technical solutions to these legitimate concerns are needed. DISCUSSION: An alternative method of operation is proposed which involves splitting the personal identifiers from the medical details at the source of notification, and separately encrypting each part using asymmetrical (public key) cryptographic methods. The identifying information is sent to a single Population Register, and the medical details to the relevant disease register. The Population Register uses probabilistic record linkage to assign a unique personal identification (UPI) number to each person notified to it, although not necessarily everyone in the entire population. This UPI is shared only with a single trusted third party whose sole function is to translate between this UPI and separate series of personal identification numbers which are specific to each disease register. SUMMARY: The system proposed would significantly improve the protection of privacy and confidentiality, while still allowing the efficient linkage of records between disease registers, under the control and supervision of the trusted third party and independent ethics committees. The proposed architecture could accommodate genetic databases and tissue banks as well as a wide range of other health and social data collections. It is important that proposals such as this are subject to widespread scrutiny by information security experts, researchers and interested members of the general public, alike

Will Gene Patents Derail the Next-Generation of Genetic Technologies?: A Reassessment of the Evidence Suggests Not

Judge Bryson recently asserted in Association for Molecular Pathology v. US Patent and Trademark Office (dissenting-in-part) that human gene patents present a significant obstacle to the next generation of innovation in genetic medicine — multiplex tests and whole-genome sequencing. His concern over the impact of gene patents on genetic testing, which coincides with his position that certain gene patents should be declared patent ineligible, reflects a widely held misperception that 20% of human genes are patented in a manner that would necessarily result in infringement by whole genome sequencing and other forms of genetic testing. In fact, the myth that 20% of human genes are patented is based on a gross misreading of a single Policy Perspective article published in Science in 2005, and an unfortunate tendency among many commentators to consider gene patents in abstract terms that disregard the critical role of patent claims in limiting the scope of a patent owner\u27s right to exclude. Analysis of the claims of 533 of the of the patents identified in the Science article as covering human genes reveals that most do not include a single claim that would be infringed by whole genome sequencing and other forms of genetic testing. In fact, it seems quite likely that, were they to be litigated, few if any of these gene patents would be found to cover genetic testing or whole genome sequencing. Furthermore, a variety of practical limitations on enforcement and remedies appear to render it unlikely that the owners of these patents would be motivated to assert them against providers of whole genome sequencing and other next-generation diagnostic technologies in a manner that would impede progress in this area. There have been numerous instances in which fears that patents would harm biomedical research and medicine have proven in retrospect to have been greatly exaggerated, and history counsels against overreacting to the current controversy over gene patents. Ironically, it might be the case that the next generation of genetic diagnostic testing innovation will be adversely impacted not by too many patents, but by a lack of adequate patent protection