364 research outputs found
Growing Graphs with Hyperedge Replacement Graph Grammars
Discovering the underlying structures present in large real world graphs is a
fundamental scientific problem. In this paper we show that a graph's clique
tree can be used to extract a hyperedge replacement grammar. If we store an
ordering from the extraction process, the extracted graph grammar is guaranteed
to generate an isomorphic copy of the original graph. Or, a stochastic
application of the graph grammar rules can be used to quickly create random
graphs. In experiments on large real world networks, we show that random
graphs, generated from extracted graph grammars, exhibit a wide range of
properties that are very similar to the original graphs. In addition to graph
properties like degree or eigenvector centrality, what a graph "looks like"
ultimately depends on small details in local graph substructures that are
difficult to define at a global level. We show that our generative graph model
is able to preserve these local substructures when generating new graphs and
performs well on new and difficult tests of model robustness.Comment: 18 pages, 19 figures, accepted to CIKM 2016 in Indianapolis, I
La infomediación: ¿Un problema para las agencias de viajes de La Plata?
El presente trabajo analiza el rol de las agencias de viajes dentro de la intermediación turística y su relación con la incorporación de las tecnologías a la vida cotidiana de los millennials, a partir del surgimiento de un nuevo canal de información conocido como infomediarios. Así es como se evaluó la utilización de los infomediarios por parte de los millennials, luego la relación entre las agencias y los infomediarios y finalmente se dio a conocer la perspectiva de los infomediarios respecto al rol de las agencias. A tal fin, se recolectaron las tres perspectivas principales (agencia de viajes, infomediarios y millennials), para identificar cuál es el rol que cumplen hoy en día las agencias de viaje desde la aparición de los infomediarios y cuáles serán las adaptaciones que vendrán. Además, se aportan los resultados obtenidos de las entrevistas realizadas en el transcurso del trabajo como información inédita sobre la temática. Finalmente, se darán las conclusiones más importantes en base a la propuesta realizada.Facultad de Ciencias Económica
A person-oriented approach to multidimensional perfectionism: perfectionism profiles in health and well-being
Advances in understanding of the perfectionism construct have been limited by an almost exclusive reliance on a variable-centered approach. This study utilized a person-oriented approach to examine Hewitt and Flett’s conceptualization of multidimensional perfectionism in relation to health and well-being. Levels of conscientiousness, extraversion, and neuroticism were also assessed. Cluster analyses were employed to examine within-person configurations of self-oriented, other-oriented, and socially prescribed perfectionism (SPP) in university students (n = 538) and adults with chronic illness (n = 773). Five unique configurations were found in both samples and three clusters replicated across samples. “Extreme perfectionists” with high scores across all perfectionism dimensions reported relatively poor physical health, psychological health, psychosocial resources, and well-being along with elevated neuroticism and conscientiousness. A group distinguished by elevated SPP also reported relatively poorer outcomes along with elevated neuroticism and lower conscientiousness. In contrast, “nonperfectionists” reported relatively elevated levels of health and well-being. These profiles differed in their links with health and well-being even after taking into account key differences in conscientiousness and neuroticism. Our results illustrate the importance of employing a person-oriented approach to the study of multidimensional perfectionism, especially as it relates to physical health, mental health, and subjective well-being
Characterization of duplicate gene evolution in the recent natural allopolyploid Tragopogon miscellus by next-generation sequencing and Sequenom iPLEX MassARRAY genotyping
The definitive version is available at www.blackwell-synergy.co
Discovery of the Optical Transient of the Gamma Ray Burst 990308
The optical transient of the faint Gamma Ray Burst 990308 was detected by the
QUEST camera on the Venezuelan 1-m Schmidt telescope starting 3.28 hours after
the burst. Our photometry gives , , , and for times ranging from 3.28 to 3.47
hours after the burst. The colors correspond to a spectral slope of close to
. Within the standard synchrotron fireball model,
this requires that the external medium be less dense than , the
electrons contain of the shock energy, and the magnetic field energy
must be less than 24% of the energy in the electrons for normal interstellar or
circumstellar densities. We also report upper limits of at 132 s
(with LOTIS), from 132-1029s (with LOTIS), at 28.2 min
(with Super-LOTIS), and a 8.5 GHz flux of at 110 days (with the
Very Large Array). WIYN 3.5-m and Keck 10-m telescopes reveal this location to
be empty of any host galaxy to and . The lack of a host
galaxy likely implies that it is either substantially subluminous or more
distant than a red shift of .Comment: ApJ Lett submitted, 5 pages, 2 figures, no space for 12 coauthor
The Chern-Simons current in systems of DNA-RNA transcriptions
A Chern-Simons current, coming from ghost and anti-ghost fields of
supersymmetry theory, can be used to define a spectrum of gene expression in
new time series data where a spinor field, as alternative representation of a
gene, is adopted instead of using the standard alphabet sequence of bases . After a general discussion on the use of supersymmetry in
biological systems, we give examples of the use of supersymmetry for living
organism, discuss the codon and anti-codon ghost fields and develop an
algebraic construction for the trash DNA, the DNA area which does not seem
active in biological systems. As a general result, all hidden states of codon
can be computed by Chern-Simons 3 forms. Finally, we plot a time series of
genetic variations of viral glycoprotein gene and host T-cell receptor gene by
using a gene tensor correlation network related to the Chern-Simons current. An
empirical analysis of genetic shift, in host cell receptor genes with separated
cluster of gene and genetic drift in viral gene, is obtained by using a tensor
correlation plot over time series data derived as the empirical mode
decomposition of Chern-Simons current.Comment: 45 pages, 30 figures, 2 table
Genome-Wide Transcriptomic and Proteomic Analyses of Bollworm-Infested Developing Cotton Bolls Revealed the Genes and Pathways Involved in the Insect Pest Defence Mechanism
Cotton bollworm, Helicoverpa armigera, is a major insect pest that feeds on cotton bolls causing extensive damage leading to crop and productivity loss. In spite of such a major impact, cotton plant response to bollworm infection is yet to be witnessed. In this context, we have studied the genome-wide response of cotton bolls infested with bollworm using transcriptomic and proteomic approaches. Further, we have validated this data using semi-quantitative real-time PCR. Comparative analyses have revealed that 39% of the transcriptome and 35% of the proteome were differentially regulated during bollworm infestation. Around 36% of significantly regulated transcripts and 45% of differentially expressed proteins were found to be involved in signalling followed by redox regulation. Further analysis showed that defence-related stress hormones and their lipid precursors, transcription factors, signalling molecules, etc. were stimulated, whereas the growth-related counterparts were suppressed during bollworm infestation. Around 26% of the significantly up-regulated proteins were defence molecules, while \u3e 50% of the significantly down-regulated were related to photosynthesis and growth. Interestingly, the biosynthesis genes for synergistically regulated jasmonate, ethylene and suppressors of the antagonistic factor salicylate were found to be up-regulated, suggesting a choice among stress-responsive phytohormone regulation. Manual curation of the enzymes and TFs highlighted the components of retrograde signalling pathways. Our data suggest that a selective regulatory mechanism directs the reallocation of metabolic resources favouring defence over growth under bollworm infestation and these insights could be exploited to develop bollworm-resistant cotton varieties
Comparative cytotoxicity of artemisinin and cisplatin and their interactions with chlorogenic acids in MCF7 breast cancer cells.
In parts of Africa and Asia, self-medication with a hot water infusion of Artemisia annua (Artemisia tea) is a common practice for a number of ailments including malaria and cancer. In our earlier work, such an extract showed better potency than artemisinin alone against both chloroquine-sensitive and -resistant parasites. In this study, in vitro tests of the infusion in MCF7 cells showed high IC50 values (>200 μM). The combination of artemisinin and 3-caffeoylquinic acid (3CA), two major components in the extract, was strongly antagonistic and gave a near total loss of cytotoxicity for artemisinin. We observed that the interaction of 3CAs with another cytotoxic compound, cisplatin, showed potentiation of activity by 2.5-fold. The chelation of cellular iron by 3CA is hypothesized as a possible explanation for the loss of artemisinin activity.This study was funded by the Engineering and Physical Sciences
Research Council (EPSRC, UK) and SensaPharm Ltd. via an Industrial
CASE PhD studentship. The award was allocated competitively
by the Chemistry Innovation Knowledge Transfer Network
(CIKTN, UK).This is the final published version. It was originally published by Wiley at http://onlinelibrary.wiley.com/doi/10.1002/cmdc.201402285/abstract
Evasion of anti-growth signaling: a key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds
The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways. Aberrations in these processes in cancer cells involve mutations and thus the suppression of genes that prevent growth, as well as mutation and activation of genes involved in driving cell growth. Using these pathways as examples, we prioritize molecular targets that might be leveraged to promote anti-growth signaling in cancer cells. Interestingly, naturally-occurring phytochemicals found in human diets (either singly or as mixtures) may promote anti-growth signaling, and do so without the potentially adverse effects associated with synthetic chemicals. We review examples of naturally-occurring phytochemicals that may be applied to prevent cancer by antagonizing growth signaling, and propose one phytochemical for each pathway. These are: epigallocatechin-3-gallate (EGCG) for the Rb pathway, luteolin for p53, curcumin for PTEN, porphyrins for Hippo, genistein for GDF15, resveratrol for ARID1A, withaferin A for Notch and diguelin for the IGF1-receptor pathway. The coordination of anti-growth signaling and natural compound studies will provide insight into the future application of these compounds in the clinical setting
Discovery of the optical transient of GRB 990308
The optical transient of the faint gamma-ray burst GRB 990308 was detected by the QUEST camera on the Venezuelan 1 m Schmidt telescope starting 3.28 hr after the burst. Our photometry gives V= 18.32 ± 0.07, R = 18.14 ± 0.06, B = 18.65 ± 0.23, and R = 18.22 ± 0.05 for times ranging from 3.28 to 3.47 hr after the burst. The colors correspond to a spectral slope of close to fv ∝ v1/3. Within the standard synchrotron fireball model, this requires that the external medium be less dense than 104 cm-3, the electrons contain more than 20% of the shock energy, and the magnetic field energy be less than 24% of the energy in the electrons for normal interstellar or circumstellar densities. We also report upper limits of V \u3e 12.0 at 132 s (with LOTIS), V \u3e 13.4 from 132 to 1029 s (with LOTIS), V \u3e 15.3 at 28.2 minutes (with Super-LOTIS), and a 8.5 GHz flux of less than 114 μJy at 110 days (with the Very Large Array). Wisconsin-Indiana-Yale-NOAO 3.5 m and Keck 10 m telescopes reveal this location to be empty of any host galaxy to R \u3e 25.7 and K \u3e 23.3. The lack of a host galaxy likely implies that it is either substantially subluminous or more distant than a redshift of ∼1.2
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