16 research outputs found
Variation in The Vitamin D Receptor Gene is Associated With Multiple Sclerosis in an Australian Population
Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS) resulting in accumulating neurological disability. The disorder is more prevalent at higher latitudes. To investigate VDR gene variation using three intragenic restriction fragment length polymorphisms (Apa I, Taq I and Fok I) in an Australian MS case-control population, one hundred and four Australian MS patients were studied with patients classified clinically as Relapsing Remitting MS (RR-MS), Secondary Progressive MS (SP-MS) or Primary Progressive MS (PP-MS). Also, 104 age-, sex-, and ethnicity-matched controls were investigated as a comparative group. Our results show a significant difference of genotype distribution frequency between the case and control groups for the functional exon 9 VDR marker Taq I (p_Gen = 0.016) and interestingly, a stronger difference for the allelic frequency (p_All = 0.0072). The Apa I alleles were also found to be associated with MS (p_All = 0.04) but genotype frequencies were not significantly different from controls (p_Gen = 0.1). The Taq and Apa variants are in very strong and significant linkage disequilibrium (D' = 0.96, P < 0.0001). The genotypic associations are strongest for the progressive forms of MS (SP-MS and PP-MS). Our results support a role for the VDR gene increasing
Emerging materials for solar cell applications: electrodeposited CdTe. Third quarter report, September 1-November 30, 1979
Major emphasis during the period was centered on improving the material properties of electrodeposited CdTe. Using newly devised means for peeling thin CdTe films off the ITO-coated glass substrates, it was possible to accurately measure material density and electrical resistivity. Density proved to be 40% below the bulk CdTe figure of about 6 gm/cm/sup 3/, while resistivity of supposedly doped CdTe films exceeded 10/sup 5/..cap omega.. - cm. These findings prompted initiation of a beneficial change in plating procedures which increased the thin film polycrystalline CdTe density to the bulk value while, at the same time, good columnar growth was obtained. Films made under the old plating process were made into Schottky diodes showing good uniformity and V/sub oc/ values generally exceeding 0.5V. Short circuit current of the best of these was 9.5mA/cm/sup 2/ despite the fact that light entered through a thick gold film and was strongly attenuated
Emerging materials for solar cell applications. First quarter report, February 15-May 31, 1979
Work to develop the theory controlling the electroplating of a compound semiconductor on a transparent, conductive substrate and to demonstrate operative solar cells using the approach is reported. The current program is divided essentially into three paralleled team efforts. The first effort centers on refining the electroplating process at Monosolar so thicker and more uniform layers of p- or n-type cadmium telluride can be plated on both In/sub 2/O/sub 3/:Sn- and Ni- coated substrates. 1 ..mu..M thick polycrystalline films have been achieved for the first time ever without peeling problems, a thickness optimum for maximum solar absorption and economy of materials. Second, work is underway at UCLA to physically and electrically characterize the films and diodes made from them. Under proper conditions Schottky diodes with better than 10/sup 4/ rectification ratios at 1.5 V were obtained along with preliminary indications of grain sizes up to 1 ..mu..M. Measurements of these diodes revealed the presence of deep trapping level(s) that may be associated with plating process impurities that since may have been eliminated. Third, work so far on developing improved techniques for depositing ITO has been successful at UCLA in their effort to eliminate persistent problems with ITO obtained from outside suppliers serving the less demanding liquid crystal display (LCD) industry
Emerging materials for solar cell applications: electrodeposited CdTe. Final report, February 14, 1979-February 14, 1980
Thin film gold/polycrystalline cadmium telluride Schottky solar cells made by electrodepositing the semiconductor on an ITO-coated glass substrate serving also as an ohmic contact demonstrated an internal efficiency of 4% over 2 mm/sup 2/ areas. During the year being reported upon, Monosolar devoted mator attention to refining the electroplating process and determining the parameters governing CdTe film stoichiometry, grain size, substrate adhesion, and quality. UCLA acting as a Monosolar sub-contractor characterized both the CdTe films themselves and solar cells made from them. Techniques were developed for making measurements on films often less than 1 micron in thickness. The highest values achieved for efficiency parameters, not necessarily all in the same cell, were V/sub oc/ = 0.5 V, J/sub sc/ = 11 mA/cm/sup 2/, and fill factor = 0.55 before corrections in the absence of anti-reflection coatings. Typical resistivities for n-CdTe films were 10/sup 5/ ..cap omega..-cm. Lifetimes of about 10/sup -10/ sec were measured. Absorption coefficient of these films is in the order of 10/sup 4/ for lambda < 0.7 ..mu..m. Measured energy gap for these CdTe films is 1.55 eV, sightly higher than the 1.45 eV value for single crystal CdTe. The activation energy of the dominating trap level is 0.55 eV. Trap density is in the order of 10/sup 16//cm/sup 3/. Schottky diodes were of excellent quality and pinhole-free. The measured barrier height varied between 0.75 and 0.85 eV. Rectification ratios of 10/sup 4/ were obtained reproducibly. Films measure about 1 inch square. Indications are that larger and more efficient low cost solar devices can readily be obtained soon using the techniques developed in this program
The conservation status of small or less well known groups of New Zealand terrestrial invertebrates
Supporting urban ecosystem services across terrestrial, marine and freshwater realms
The terrestrial, freshwater and marine realms all provide essential ecosystem services in urban environments. However, the services provided by each realm are often considered independently, which ignores the synergies between them and risks underestimating the benefits derived collectively. Greater research collaboration across these realms, and an integrated approach to management decisions can help to support urban developments and restoration projects in maintaining or enhancing ecosystem services. The aim of this paper is to highlight the synergies and trade-offs among ecosystem services provided by each realm and to offer suggestions on how to improve current practice. We use case studies to illustrate the flow of services across realms. In our call to better integrate research and management across realms, we present a framework that provides a 6-step process for conducting collaborative research and management with an Australian perspective. Our framework considers unifying language, sharing, and understanding of desired outcomes, conducting cost-benefit analyses to minimise trade-offs, using multiple modes of communication for stakeholders, and applying research outcomes to inform regulation. It can be applied to improve collaboration among researchers, managers and planners from all realms, leading to strategic allocation of resources, increased protection of urban natural resources and improved environmental regulation with broad public support