7,290 research outputs found
Detailed quantification of cardiac ventricular myocardial architecture in the embryonic and fetal mouse heart by application of structure tensor analysis to high resolution episcopic microscopic data
The mammalian heart, which is one of the first organs to form and function during embryogenesis, develops from a simple tube into a complex organ able to efficiently pump blood towards the rest of the body. The progressive growth of the compact myocardium during embryonic development is accompanied by changes in its structural complexity and organisation. However, how myocardial myoarchitecture develops during embryogenesis remain poorly understood. To date, analysis of heart development has focused mainly on qualitative descriptions using selected 2D histological sections. High resolution episcopic microscopy (HREM) is a novel microscopic imaging technique that enables to obtain high-resolution three-dimensional images of the heart and perform detailed quantitative analyses of heart development. In this work, we performed a detailed characterization of the development of myocardial architecture in wildtype mice, from E14.5 to E18.5, by means of structure tensor analysis applied to HREM images of the heart. Our results shows that even at E14.5, myocytes are already aligned, showing a gradual change in their helical angle from positive angulation in the endocardium towards negative angulation in the epicardium. Moreover, there is gradual increase in the degree of myocardial organisation concomitant with myocardial growth. However, the development of the myoarchitecture is heterogeneous showing regional differences between ventricles, ventricular walls as well as between myocardial layers, with different growth patterning between the endocardium and epicardium. We also found that the percentage of circumferentially arranged myocytes within the LV significantly increases with gestational age. Finally, we found that fractional anisotropy (FA) within the LV gradually increases with gestational age, while the FA within RV remains unchanged
Meditation awareness training for the treatment of workaholism: a controlled trial
Background and aims: Workaholism is a form of behavioral addiction that can lead to reduced life and job satisfaction, anxiety, depression, burnout, work–family conflict, and impaired productivity. Given the number of people affected, there is a need for more targeted workaholism treatments. Findings from previous case studies successfully utilizing second-generation mindfulness-based interventions (SG-MBIs) for treating behavioral addiction suggest that SG-MBIs may be suitable for treating workaholism. This study conducted a controlled trial to investigate the effects of an SG-MBI known as meditation awareness training (MAT) on workaholism. Methods: Male and female adults suffering from workaholism (n = 73) were allocated to MAT or a waiting-list control group. Assessments were performed at pre-, post-, and 3-month follow-up phases. Results: MAT participants demonstrated significant and sustained improvements over control-group participants in workaholism symptomatology, job satisfaction, work engagement, work duration, and psychological distress. Furthermore, compared to the control group, MAT participants demonstrated a significant reduction in hours spent working but without a decline in job performance. Discussion and conclusions: MAT may be a suitable intervention for treating workaholism. Further controlled intervention studies investigating the effects of SG-MBIs on workaholism are warranted
IView: introgression library visualization and query tool
<p>Abstract</p> <p>Background</p> <p>An introgression library is a family of near-isogenic lines in a common genetic background, each of which carries one or more genomic regions contributed by a donor genome. Near-isogenic lines are powerful genetic resources for the analysis of phenotypic variation and are important for map-base cloning genes underlying mutations and traits. With many thousands of distinct genotypes, querying introgression libraries for lines of interest is an issue. </p> <p>Results</p> <p>We have created IView, a tool to graphically display and query near-isogenic line libraries for specific introgressions. This tool incorporates a web interface for displaying the location and extent of introgressions. Each genetic marker is associated with a position on a reference map. Users can search for introgressions using marker names, or chromosome number and map positions. This search results in a display of lines carrying an introgression at the specified position. Upon selecting one of the lines, color-coded introgressions on all chromosomes of the line are displayed graphically.</p> <p>The source code for IView can be downloaded from <url>http://xrl.us/iview</url>. </p> <p>Conclusions</p> <p>IView will be useful for those wanting to make introgression data from their stock of germplasm searchable. </p
Nonlinear damping in mechanical resonators based on graphene and carbon nanotubes
Carbon nanotubes and graphene allow fabricating outstanding nanomechanical
resonators. They hold promise for various scientific and technological
applications, including sensing of mass, force, and charge, as well as the
study of quantum phenomena at the mesoscopic scale. Here, we have discovered
that the dynamics of nanotube and graphene resonators is in fact highly exotic.
We propose an unprecedented scenario where mechanical dissipation is entirely
determined by nonlinear damping. As a striking consequence, the quality factor
Q strongly depends on the amplitude of the motion. This scenario is radically
different from that of other resonators, whose dissipation is dominated by a
linear damping term. We believe that the difference stems from the reduced
dimensionality of carbon nanotubes and graphene. Besides, we exploit the
nonlinear nature of the damping to improve the figure of merit of
nanotube/graphene resonators.Comment: main text with 4 figures, supplementary informatio
Induction of fibroblast senescence generates a non-fibrogenic myofibroblast phenotype that differentially impacts on cancer prognosis
Cancer-associated fibroblasts (CAF) remain a poorly characterized, heterogeneous cell population. Here we characterized two previously described tumor-promoting CAF sub-types, smooth muscle actin (SMA)-positive myofibroblasts and senescent fibroblasts, identifying a novel link between the two
Pneumocystis primary infection in non-immunosuppressed infants in Lima, Peru
Objectives:
To provide original data on Pneumocystis primary infection in non-immunosuppressed infants from Peru. /
Methods:
A cross sectional study was performed. Infants less than seven months old, without any underlying medical conditions attending the “well baby” outpatient clinic at one hospital in Lima, Peru were prospectively enrolled during a 15-month period from November 2016 to February 2018. All had a nasopharyngeal aspirate (NPA) for detection of P. jirovecii DNA using a PCR assay, regardless of respiratory symptoms. P. jirovecii DNA detection was considered to represent pulmonary colonization contemporaneous with Pneumocystis primary infection. Associations between infants’ clinical and demographic characteristics and results of P. jirovecii DNA detection were analyzed. /
Results:
P. jirovecii DNA was detected in 45 of 146 infants (30.8%) and detection was not associated with concurrent respiratory symptoms in 40 of 45 infants. Infants with P. jirovecii had a lower mean age when compared to infants not colonized (p <0.05). The highest frequency of P. jirovecii was observed in 2-3-month-old infants (p < 0.01) and in the cooler winter and spring seasons (p <0.01). Multivariable analysis showed that infants living in a home with ≤ 1 bedroom were more likely to be colonized; Odds Ratio =3.03 (95%CI 1.31-7.00; p =0.01). /
Conclusion:
Pneumocystis primary infection in this single site in Lima, Peru, was most frequently observed in 2-3-month-old infants, in winter and spring seasons, and with higher detection rates being associated with household conditions favoring close inter-individual contacts and potential transmission of P. jirovecii
A Cross‐Sectional Assessment of Frailty, Falls and Perceptions of Ageing in People Living with HIV Using an mHealth Platform
Objective: To evaluate frailty, falls and perceptions of ageing among clinically stable individuals with HIV, engaged with remote healthcare delivered via a novel smartphone application.
Methods: This was a multi-centre European cross-sectional, questionnaire-based sub-study of EmERGE participants. Frailty was assessed using the five-item FRAIL scale. Present criteria were summed and categorized as follows: 0, robust; 1-2, pre-frail; 3-5, frail. Falls history and EQ-5D-5L quality of life measure were completed. Participants were asked their felt age and personal satisfaction with ageing.
Results: A total of 1373 participated, with a mean age of 45 (± 9.8) years. Frailty was uncommon at 2%; 12.4% fell in the previous year, 58.8% of these recurrently. Mood symptoms and pain were prevalent, at 43.3% and 31.8%, respectively. Ageing satisfaction was high at 76.4%, with 74.6% feeling younger than their chronological age; the mean felt age was 39.3 years. In multivariable analysis, mood symptoms and pain were positively associated with frailty, falls and ageing dissatisfaction. An increase in pain severity and mood symptoms were respectively associated with 34% and 63% increased odds of pre-frailty/frailty. An increment in pain symptoms was associated with a 71% increase in odds of falling. Pain was associated with ageing poorly, as were mood symptoms, with odds of dissatisfaction increasing by 34% per increment in severity.
Conclusions: Although uncommon, frailty, falls and ageing dissatisfaction were seen in a younger cohort with medically stable HIV infection using a remote care model, promoting screening as advocated by European guidelines. These were more common in those with pain or mood symptoms, which should be proactively managed in clinical care and explored further in future research.info:eu-repo/semantics/publishedVersio
Astrophysical Fluids of Novae: High Resolution Pre-decay X-ray spectrum of V4743 Sagittarii
Eight X-ray observations of V4743 Sgr (2002), observed with Chandra and
XMM-Newton are presented. The nova turned off some time between days 301.9 and
371, and the X-ray flux subsequently decreased from day 301.9 to 526 following
an exponential decline time scale of days. We use the absorption
lines present in the SSS spectrum for diagnostic purposes, and characterize the
physics and the dynamics of the expanding atmosphere during the explosion of
the nova. The information extracted from this first stage is then used as input
for computing full photoionization models of the ejecta in V4743 Sgr. The SSS
spectrum is modeled with a simple black-body and multiplicative Gaussian lines,
which provides us of a general kinematical picture of the system, before it
decays to its faint phase (Ness et al. 2003). In the grating spectra taken
between days 180.4 and 370, we can resolve the line profiles of absorption
lines arising from H-like and He-like C, N, and O, including transitions
involving higher principal quantum numbers. Except for a few interstellar
lines, all lines are significantly blue-shifted, yielding velocities between
1000 and 6000 km/s which implies an ongoing mass loss. It is shown that
significant expansion and mass loss occur during this phase of the explosion,
at a rate . Our measurements show that the efficiency of the amount of
energy used for the motion of the ejecta, defined as the ratio between the
kinetic luminosity and the radiated luminosity , is
of the order of one.Comment: 25 pages, 9 figures. Accepted in book: Recent Advances in Fluid
Dynamics with Environmental Applications, pp.365-39
Epidemiological and transmissibility analysis of influenza A(H1N1)v in a southern hemisphere setting: Peru
We present a preliminary analysis of 1,771 confirmed cases of influenza A(H1N1)v reported in Peru by 17 July including the frequency of the clinical characteristics, the spatial and age distribution of the cases and the estimate of the transmission potential. Age-specific frequency of cases was highest among school age children and young adults, with the lowest frequency of cases among seniors, a pattern that is consistent with reports from other countries. Estimates of the reproduction number lie in the range of 1.2 to 1.7, which is broadly consistent with previous estimates for this pandemic in other regions. Validation of these estimates will be possible as additional data become available
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