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Subcellular partitioning of MRP RNA assessed by ultrastructural and biochemical analysis.
A small RNA encoded within the nucleus is an essential subunit of a RNA processing endonuclease (RNase MRP) hypothesized to generate primers for mitochondrial DNA replication from the heavy strand origin of replication. Controversy has arisen, however, concerning the authenticity of an intramitochondrial pool of MRP RNA, and has called into question the existence of pathways for nucleo-mitochondrial transport of nucleic acids in animal cells. In an effort to resolve this controversy, we combined ultrastructural in situ hybridization and biochemical techniques to assess the subcellular partitioning of MRP RNA. Cryosections of mouse cardiomyocytes were hybridized with biotin-labeled RNA probes complementary to different regions of MRP RNA and varying in length from 115 to 230 nucleotides, followed by immunogold labeling. In addition, we transfected mouse C2C12 myogenic cells with constructs bearing mutated forms of the mouse MRP RNA gene and compared the relative abundance of the resulting transcripts to that of control RNAs within whole cell and mitochondrial fractions. In the former analysis we observed preferential localization of MRP RNA to nucleoli and mitochondria in comparison to the nucleoplasm and cytoplasm. In the latter series of studies we observed that wild-type MRP RNA partitions to the mitochondrial fraction by comparison to other RNA transcripts that are localized to the extramitochondrial cytoplasmic space (28S rRNA) or to the nucleoplasm (U1 snRNA). Deletions within 5' or 3' regions of the MRP RNA gene produced transcripts that remain competent for mitochondrial targeting. In contrast, deletion of the midportion of the coding region (nt 118 to 175) of the MRP RNA gene resulted in transcripts that fail to partition to the mitochondrial fraction. We conclude that an authentic intramitochondrial pool of MRP RNA is present in these actively respiring cells, and that specific structural determinants within the MRP RNA molecule permit it to be partitioned to mitochondria
Conflict-free connection numbers of line graphs
A path in an edge-colored graph is called \emph{conflict-free} if it contains
at least one color used on exactly one of its edges. An edge-colored graph
is \emph{conflict-free connected} if for any two distinct vertices of ,
there is a conflict-free path connecting them. For a connected graph , the
\emph{conflict-free connection number} of , denoted by , is defined
as the minimum number of colors that are required to make conflict-free
connected. In this paper, we investigate the conflict-free connection numbers
of connected claw-free graphs, especially line graphs. We first show that for
an arbitrary connected graph , there exists a positive integer such that
. Secondly, we get the exact value of the conflict-free
connection number of a connected claw-free graph, especially a connected line
graph. Thirdly, we prove that for an arbitrary connected graph and an
arbitrary positive integer , we always have , with only the exception that is isomorphic to a star of order
at least~ and . Finally, we obtain the exact values of ,
and use them as an efficient tool to get the smallest nonnegative integer
such that .Comment: 11 page
A Strategy for Imidazotetrazine Prodrugs with Anti-cancer Activity Independent of MGMT and MMR
The imidazotetrazine ring is an acid-stable precursor and prodrug of highly-reactive alkyl diazonium ions. We have shown that this reactivity can be managed productively in an aqueous system for the generation of aziridinium ions with 96% efficiency. The new compounds are potent DNA alkylators and have antitumor activity independent of the O6-methylguanine-DNA methyltransferase and DNA mismatch repair constraints that limit the use of temozolomide
MD4 IMPACT OF THE MEDICARE MODERNIZATION ACT OF 2003 ON PART B DRUG USE AND SPENDING: A CASE STUDY OF BIOLOGICALS FOR RHEUMATOID ARTHRITIS
Attitude and Beliefs of Nigerian Undergraduates to Spectacle Wear
Background: Uncorrected refractive error is a common cause of preventable visual impairment. Glasses are the cheapest and commonest form of correction of refractive errors. To achieve this, patients must exhibit good compliance to spectacle wear. Patients’ attitude and perception of glasses and eye health could affect compliance to spectacle wear.Objective: To determine the attitude and beliefs of Nigerian undergraduates to spectacle wear.Method: A cross sectional study of 500 undergraduates of the University of Benin, Nigeria. Age range was from 18 to 30 years, mean age 23 ± 2.7 years. There were 269 males and 231 females. Semi structured questionnaires were distributed to the participants and collected same day after completion.Results: Two-thirds (68%) of the total population studied had not heard of refractive error. About a third (38%) believed wearing eyeglasses was one of the methods used to correct refractive error. Half (50%) believed they would wear spectacles if prescribed with one by their doctor. Sixty-four percent believed eyeglasses are harmful to the eyes; and 65% did not know that eyeglasses could be used to relieve other forms of ocular discomfort like headache and tearing. Fifty-seven per cent of respondents saw people who wore eyeglasses as visually handicapped, while 60% believed that eyeglasses were meant for old people. Majority of the respondents (56%) believed that they would be teased if they wore glasses.Conclusion: Knowledge of refractive errors and acceptance of glasses for the correction of refractive errors among Nigerian undergraduates is not encouraging. Public enlightenment programs to promote benefits of wearing prescribed spectacles are needed.Keywords: Refractive error, glasses, spectacle, students, blindnes
Multiclass Semi-Supervised Learning on Graphs using Ginzburg-Landau Functional Minimization
We present a graph-based variational algorithm for classification of
high-dimensional data, generalizing the binary diffuse interface model to the
case of multiple classes. Motivated by total variation techniques, the method
involves minimizing an energy functional made up of three terms. The first two
terms promote a stepwise continuous classification function with sharp
transitions between classes, while preserving symmetry among the class labels.
The third term is a data fidelity term, allowing us to incorporate prior
information into the model in a semi-supervised framework. The performance of
the algorithm on synthetic data, as well as on the COIL and MNIST benchmark
datasets, is competitive with state-of-the-art graph-based multiclass
segmentation methods.Comment: 16 pages, to appear in Springer's Lecture Notes in Computer Science
volume "Pattern Recognition Applications and Methods 2013", part of series on
Advances in Intelligent and Soft Computin
Meaning-focused and Quantum-inspired Information Retrieval
In recent years, quantum-based methods have promisingly integrated the
traditional procedures in information retrieval (IR) and natural language
processing (NLP). Inspired by our research on the identification and
application of quantum structures in cognition, more specifically our work on
the representation of concepts and their combinations, we put forward a
'quantum meaning based' framework for structured query retrieval in text
corpora and standardized testing corpora. This scheme for IR rests on
considering as basic notions, (i) 'entities of meaning', e.g., concepts and
their combinations and (ii) traces of such entities of meaning, which is how
documents are considered in this approach. The meaning content of these
'entities of meaning' is reconstructed by solving an 'inverse problem' in the
quantum formalism, consisting of reconstructing the full states of the entities
of meaning from their collapsed states identified as traces in relevant
documents. The advantages with respect to traditional approaches, such as
Latent Semantic Analysis (LSA), are discussed by means of concrete examples.Comment: 11 page
The generalized 3-edge-connectivity of lexicographic product graphs
The generalized -edge-connectivity of a graph is a
generalization of the concept of edge-connectivity. The lexicographic product
of two graphs and , denoted by , is an important graph
product. In this paper, we mainly study the generalized 3-edge-connectivity of
, and get upper and lower bounds of .
Moreover, all bounds are sharp.Comment: 14 page
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