Communications Biophysics

Contains reports on five research projects.National Institutes of Health (Grant 1 P01 GM-14940-01)Joint Services Electronics Program under Contract DA 28-043-AMC-02536(E

Real-Time Measurement of Thin Film Thickness During Plasma Processing

An in situ single point two-color laser interferometer is used to monitor in real-time the thickness of thin transparent films during processing. The instantaneous change of film thickness is determined by comparing the measured laser reflection interference to that calculated by a model. The etch or deposition rates of the film are determined within 1–2 seconds. The film thickness is also determined in real-time from the phase difference of the reflected laser intensity between the two laser colors. Use of two-color laser interferometry improves the accuracy of the calculated etch or growth rates of the film considerably. Moreover, the two colors provide a clear distinction between film etching and deposition, which may often occur during the same process, and can not be determined by a single color interferometer. The uniformity of the film's etch or deposition rates across the substrate is monitored by an in situ full-wafer image interferometer. The combined use of these two sensors provide instantaneous information of the film thickness, etch or growth rates, as well as time averaged uniformity of the process rates. This diagnostic setup is very useful for process development and monitoring, which is also suitable for manufacturing environment, and can be used for real-time process control.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45461/1/11088_2004_Article_412642.pd

A Computational Framework for Influenza Antigenic Cartography

Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI) assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses) and reference antisera (antibodies). Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS). In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses), we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap

Locating Photography

The specter of global dissemination haunted photography from its very beginning. This chapter explains two aspects of photography's “globalization”: its use as a “western” technique to document an increasingly colonized world and its dissemination around the world and its adoption by local practitioners. In rural and small‐town central India, the studio retains a central place in most people's encounters with photography. Martín Chambi would retain a lifelong adherence to the purity of the photographic image but other indigenista photographers, such as Juan Manuel Figueroa Aznar, would increasingly use paint alongside photography. A World System Photography, seen in networks that fold locally articulated practices into trajectories that fuse technics, history, and culture, can help people think in new ways about the “location” of photography. Locations have to be re‐imagined as “Terra Infirma”, unstable and complex positions which may have more of the quality of linking sections of a network than of territories

Loss, Bereavement and Creativity: Meanings and Uses

Within the field of death and bereavement studies, the assumption that loss and bereavement provide the spur to creativity has become so widespread as to assume the status of a conventional wisdom. With this in mind, this article surveys the literature on the topic, extant, and contemporary, revealing its diffuseness as well as the multidisciplinary synergies produced by those working in disparate academic and clinical fields of practice. In so doing, the article explores what it means to be creative in the context of loss and bereavement, the potential for self-development and personal growth offered by creativity and loss, the theoretical premises linking creativity and loss, and the application and challenges for creative therapies in the institutional context of hospice and palliative car

Research on Teaching and Learning Mathematics at the Tertiary Level:State-of-the-art and Looking Ahead

This topical survey focuses on research in tertiary mathematics education, a field that has experienced considerable growth over the last 10 years. Drawing on the most recent journal publication as well as the latest advances from recent high quality conference proceedings, our review culls out the following five emergent areas of interest: mathematics teaching at the tertiary level; the role of mathematics in other disciplines; textbooks, assessment and students’ studying practices; transition to the tertiary level; and theoretical-methodological advances. We conclude the survey with a discussion of some potential ways forward for future research in this new and rapidly developing domain of inquiry

The effects of Δ9-tetrahydrocannabinol on the dopamine system

Δ(9)-tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, is a pressing concern to global mental health. Patterns of use are changing drastically due to legalisation, availability of synthetic analogues (‘spice’), cannavaping and aggrandizements in the purported therapeutic effects of cannabis. Many of THC’s reinforcing effects are mediated by the dopamine system. Due to complex cannabinoid-dopamine interactions there is conflicting evidence from human and animal research fields. Acute THC causes increased dopamine release and neuron activity, whilst long-term use is associated with blunting of the dopamine system. Future research must examine the long-term and developmental dopaminergic effects of the drug