209 research outputs found
How to project a bipartite network?
The one-mode projecting is extensively used to compress the bipartite
networks. Since the one-mode projection is always less informative than the
bipartite representation, a proper weighting method is required to better
retain the original information. In this article, inspired by the network-based
resource-allocation dynamics, we raise a weighting method, which can be
directly applied in extracting the hidden information of networks, with
remarkably better performance than the widely used global ranking method as
well as collaborative filtering. This work not only provides a creditable
method in compressing bipartite networks, but also highlights a possible way
for the better solution of a long-standing challenge in modern information
science: How to do personal recommendation?Comment: 7 pages, 4 figure
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Blood Flow in silico: From Single Cells to Blood Rheology
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Mesoscale hydrodynamics simulations of red blood cells under flow have provided much new
insight into their shapes and dynamics in microchannel flow. The presented results range from the behavior
of single cells in confinement and the shape changes in sedimentation, to the clustering and arrangement of
many cells in microchannels and the viscosity of red blood cell suspensions under shear flow. The interaction
of red blood cells with other particles and cells, such as white blood cells, platelets, and drug carriers, shows
an essential role of red blood cells in the margination of other blood components
Host--parasite models on graphs
The behavior of two interacting populations, ``hosts''and ``parasites'', is
investigated on Cayley trees and scale-free networks. In the former case
analytical and numerical arguments elucidate a phase diagram, whose most
interesting feature is the absence of a tri-critical point as a function of the
two independent spreading parameters. For scale-free graphs, the parasite
population can be described effectively by
Susceptible-Infected-Susceptible-type dynamics in a host background. This is
shown both by considering the appropriate dynamical equations and by numerical
simulations on Barab\'asi-Albert networks with the major implication that in
the termodynamic limit the critical parasite spreading parameter vanishes.Comment: 10 pages, 6 figures, submitted to PRE; analytics redone, new
calculations added, references added, appendix remove
Pseudoexons provide a mechanism for allele-specific expression of APC in familial adenomatous polyposis
Allele-specific expression (ASE) of the Adenomatous Polyposis Coli (APC) gene occurs in up to one-third of families with adenomatous polyposis (FAP) that have screened mutation-negative by conventional techniques. To advance our understanding of the genomic basis of this phenomenon, 54 APC mutation-negative families (21 with classical FAP and 33 with attenuated FAP, AFAP) were investigated. We focused on four families with validated ASE and scrutinized these families by sequencing of the blood transcriptomes (RNA-seq) and genomes (WGS). Three families, two with classical FAP and one with AFAP, revealed deep intronic mutations associated with pseudoexons. In all three families, intronic mutations (c.646-1806T > G in intron 6, c.1408+729A > G in intron 11, and c.1408+731C > T in intron 11) created new splice donor sites resulting in the insertion of intronic sequences (of 127 bp, 83 bp, and 83 bp, respectively) in the APC transcript. The respective intronic mutations were absent in the remaining polyposis families and the general population. Premature stop of translation as the predicted consequence as well as co-segregation with polyposis supported the pathogenicity of the pseudoexons. We conclude that next generation sequencing on RNA and genomic DNA is an effective strategy to reveal and validate pseudoexons that are regularly missed by traditional screening methods and is worth considering in apparent mutation-negative polyposis families.Instituto Multidisciplinario de BiologÃa Celula
Correlations in Bipartite Collaboration Networks
Collaboration networks are studied as an example of growing bipartite
networks. These have been previously observed to have structure such as
positive correlations between nearest-neighbour degrees. However, a detailed
understanding of the origin of this phenomenon and the growth dynamics is
lacking. Both of these are analyzed empirically and simulated using various
models. A new one is presented, incorporating empirically necessary ingredients
such as bipartiteness and sublinear preferential attachment. This, and a
recently proposed model of team assembly both agree roughly with some empirical
observations and fail in several others.Comment: 13 pages, 17 figures, 2 table, submitted to JSTAT; manuscript
reorganized, figures and a table adde
Academic experience satisfaction of pharmacy and dentistry students
Objective: To assess the psychometric properties of the Academic Experience
Satisfaction Scale (ESEA) applied to Pharmacy and Dentistry students and investigate the
effect of demographic and course-related characteristics on the ESEA factors.
Methods: This was a cross-sectional study. Academic satisfaction was assessed by the
ESEA. Construct validity was measured by confirmatory factor analysis (CFI, TLI, RMSEA).
The composite reliability (CR) and the ordinal α were estimated. Structural model was
elaborated considering demographic and course-related characteristics as the
independent variable and ESEA factors as the dependent variables. The model fit and
path estimates significance (β) were evaluated (z test; α = 5%). Results: 544 students
participated in the study (70.0% female; mean age: 21.4 ± 2.4 years; 52.4% dental
students). ESEA showed adequate fit to the data (CFI = 0.90; TLI = 0.90; RMSEA = 0.064,
CR and α ≥ 0.88). In general, students reported being satisfied with their academic
experience. Dental students and those from the first and second years of the course
showed greater satisfaction with the academic experience. Sex did not have a significant
impact on any of the scale's factors. Conclusion: ESEA produced valid and reliable
data. Course-related characteristics, but not demographic characteristics, significantly
affected the academic experience of students.info:eu-repo/semantics/publishedVersio
Early diagnosis of temporomandibular joint involvement in juvenile idiopathic arthritis: a pilot study comparing clinical examination and ultrasound to magnetic resonance imaging
Objectives. To study the validity of both rheumatological and orthodontic examinations and ultrasound (US) as screening methods for early diagnosis of TMJ arthritis against the gold standard MRI. Methods. Thirty consecutive juvenile idiopathic arthritis (JIA) patients were included in this pilot study. Rheumatological and orthodontic examinations as well as US were performed within 1 month of the MRI in a blinded fashion. Joint effusion and/or increased contrast enhancement of synovium or bone were considered signs of active arthritis on MRI. Results. A total of 19/30 (63%) patients and 33/60 (55%) joints had signs of TMJ involvement on MRI. This was associated with condylar deformity in 9/19 (47%) patients and 15/33 (45%) joints. Rheumatological, orthodontic and US examinations correctly diagnosed 11 (58%), 9 (47%) and 6 (33%) patients, respectively, with active TMJ arthritis, but misdiagnosed 8 (42%), 10 (53%) and 12 (67%) patients, respectively, as having no signs of inflammation. The best predictor for active arthritis on MRI was a reduced maximum mouth opening. Conclusion. None of the methods tested was able to reliably predict the presence or absence of MRI-proven inflammation in the TMJ in our cohort of JIA patients. US was the least useful of all methods tested to exclude active TMJ arthriti
Impact of body and orofacial appearance on life satisfaction among Brazilian adults
Aims
1. to elaborate a general model of physical appearance taking into account body image (BI)
and orofacial appearance (OA) components; and 2. to evaluate the impact of BI and OA on
life satisfaction among Brazilian adults.
Methods
This is a cross-sectional observational study. The cognitive, behavioral, affective, and satisfaction/
dissatisfaction aspects of BI, the satisfaction and psychosocial impact of OA, and life
satisfaction were evaluated by self-reported psychometric scales. Principal Component
Analysis and Parallel Analysis were performed. Structural equation models were elaborated
to estimate the impact of BI and OA on life satisfaction. The fit of the models was verified
and the significance of the path estimates (β) was evaluated using z-tests (α = 5%).
Results
A total of 1,940 individuals participated in the study (age: mean = 24.8, standard deviation =
5.7 years; females = 70.1%). In the male sample, three physical appearance factors were
retained (OA, cognitive and behavioral components of BI, and affective and satisfaction/dissatisfaction
components of BI). In the female sample, two factors were retained (OA and all
components of BI). All factors had significant impact on life satisfaction (β = |0.26|-|0.48|,
p<0.001) in both samples. Individuals dissatisfied with BI and OA had lower levels of life satisfaction.
For men, the affective and satisfaction components of BI had a greater impact on
life satisfaction (β = 0.48, p<0.001) than the other factors (β =] -0.30;-0.25[, p<0.001). For
women, both BI and OA had a similar impact (BI: β = -0.30, p<0.001; OA: β = -0.32,
p<0.001). Conclusion
BI and OA formed distinct clusters in the physical appearance evaluation. Physical appearance
was perceived differently by men and women, fostering discussion about the sociocultural
construction of the body. BI and OA had a significant impact on life satisfaction and
should be considered in assessment and treatment protocols.info:eu-repo/semantics/publishedVersio
Assessing the length of the mandibular ramus and the condylar process: a comparison of OPG, CBCT, CT, MRI, and lateral cephalometric measurements
SummaryBackground/Objectives: To compare different imaging procedures [cone beam computed tomography (CBCT), computed tomography (CT), magnetic resonance imaging (MRI), orthopantomography (OPG), and lateral cephalometry (LC)] for assessing the mandibular height [ramus height (RH)] and condylar process (CondProc) length as they reflect mandibular growth. Materials/Methods: The RH and CondProc of eight cadaver heads (each side separately) were measured using CBCT, CT, MRI, OPG, and LC. They were measured twice by two independent observers parallel to the posterior border of the mandibular ramus. An intraclass correlation coefficient (ICC) was used to assess the inter- and intraobserver reliability. The coefficient of variation was used to elucidate precision. Bland-Altman (BA) plots were used to assess the agreement between the procedures and the intra- and interobserver measurements. Results: All procedures, with the exception of LC, showed good intra- and interobserver agreement (maximum range of agreement: 5.3mm) and excellent reliability (ICC > 0.9). The BA plot analysis for the CondProc and RH showed similar ranges of agreement between MRI, CT, and CBCT (maximum 6.4mm) but higher ranges for OPG and LC. The MRI and OPG values were generally smaller. Conclusions/Implications: All 3D imaging procedures yielded nearly equal results when used to measure the CondProc and RH. MRI is recommended because it avoids ionizing radiation and has higher sensitivity in the detection of inflammation. A 2-year threshold for detecting growth in the follow-up period should be taken into account for all 3D imaging methods. Measuring the RH is recommended for the follow-up of condylar growth because reference values for annual increments are publishe
On the Number of Closed Factors in a Word
A closed word (a.k.a. periodic-like word or complete first return) is a word
whose longest border does not have internal occurrences, or, equivalently,
whose longest repeated prefix is not right special. We investigate the
structure of closed factors of words. We show that a word of length
contains at least distinct closed factors, and characterize those words
having exactly closed factors. Furthermore, we show that a word of length
can contain many distinct closed factors.Comment: Accepted to LATA 201
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