35 research outputs found
Exploring potential germline associated roles of the TRIM-NHL protein NHL-2Â through RNAi screening
TRIM-NHL proteins are highly conserved regulators of developmental pathways in vertebrates and invertebrates. The TRIM-NHL family member NHL-2 in Caenorhabditis elegans functions as a miRNA cofactor to regulate developmental timing. Similar regulatory roles have been reported in other model systems, with the mammalian ortholog in mice, TRIM32, contributing to muscle and neuronal cell proliferation via miRNA activity. Given the interest associated with TRIM-NHL family proteins, we aimed to further investigate the role of NHL-2 in C. elegans development by using a synthetic RNAi screening approach. Using the ORFeome library, we knocked down 11,942 genes in wild-type animals and nhl-2 null mutants. In total, we identified 42 genes that produced strong reproductive synthetic phenotypes when knocked down in nhl-2 null mutants, with little or no change when knocked down in wild-type animals. These included genes associated with transcriptional processes, chromosomal integrity, and key cofactors of the germline small 22G RNA pathway.Gregory M. Davis, Wai Y. Low, Joshua W.T. Anderson and Peter R. Boa
Current-voltage characteristic of parallel-plane ionization chamber with inhomogeneous ionization
The balances of particles and charges in the volume of parallel-plane
ionization chamber are considered. Differential equations describing the
distribution of current densities in the chamber volume are obtained. As a
result of the differential equations solution an analytical form of the
current-voltage characteristic of parallel-plane ionization chamber with
inhomogeneous ionization in the volume is got.Comment: 8 pages, 4 figure
Analytical form of current-voltage characteristic of parallel-plane, cylindrical and spherical ionization chambers with homogeneous ionization
The elementary processes taking place in the formation of charged particles
and their flow in parallel-plane, cylindrical and spherical ionization chambers
are considered. On the basis of particles and charges balance a differential
equation describing the distribution of current densities in the ionization
chamber volume is obtained. As a result of the differential equation solution
an analytical form of the current-voltage characteristic of an ionization
chamber with homogeneous ionization is obtained. For the parallel-plane case
the comparison with experimental data is performed.Comment: 20 pages, 6 figures, 2 tables; changed conten
General recombination in ionization chambers with spatially non-uniform ionization intensity—two special cases
Recidivism and Likelihood Functions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67635/2/10.1177_0193841X7900300110.pd
On modifications to the long-term survival mixture model in the presence of competing risks
A mixture model for long-term survivors has been adopted in various fields such as biostatistics and criminology where some individuals may never experience the type of failure under study. It is directly applicable in situations where the only information available from follow-up on individuals who will never experience this type of failure is in the form of censored observations. In this paper, we consider a modification to the model so that it still applies in the case where during the follow-up period it becomes known that an individual will never experience failure from the cause of interest. Unless a model allows for this additional information, a consistent survival analysis will not be obtained. A partial maximum likelihood (ML) approach is proposed that preserves the simplicity of the long-term survival mixture model and provides consistent estimators of the quantities of interest. Some simulation experiments are performed to assess the efficiency of the partial ML approach relative to the full ML approach for survival in the presence of competing risks