309 research outputs found
Stochastic Processes in Yellow and Red Pulsating Variables
Random changes in pulsation period are well established in cool pulsating
stars, in particular the red giant variables: Miras, semi-regulars of types A
and B, and RV Tau variables. Such effects are also observed in a handful of
Cepheids, the SX Phe variable XX Cyg, and, most recently, the red supergiant
variable, BC Cyg, a type C semi-regular. The nature of such fluctuations is
seemingly random over a few pulsation cycles of the stars, yet the regularity
of the primary pulsation mechanism dominates over the long term. The degree of
stochasticity is linked to the dimensions of the stars, the randomness
parameter 'e' appearing to correlate closely with mean stellar radius through
the period 'P', with an average value of e/P = 0.0136+-0.0005. The physical
processes responsible for such fluctuations are uncertain, but presumably
originate in temporal modifications of envelope convection in such stars.Comment: Poster given at the "Stellar Pulsation: Challenges for Theory and
Observation" conference in Santa Fe, New Mexico (2009
Changes of Leptin concentration in plasma in patients with spinal cord injury: A Meta-analysis
Objective:The aim of this study was to investigate changes of leptin concentration in plasma in patients with spinal cord injury to come to a single concept by using a Meta-analysis.Setting:Systematic Review.Methods:Searching relevant articles was performed in Ovid data base, Medline (PubMed) EMBASE, Google Scholar, Cochrane and Scopus up to February 2013. Five articles were selected using two independent reviewers. Analysis were performed using SPSS version 18 and Comparative Meta-analysis software version 2.0.Results:The combined analysis with confidence interval of 95 using comprehensive meta-analysis showed significant higher leptin levels in patients with spinal cord injury in comparison with able bodies (P<0.0001). The effect of spinal lesion level on plasma leptin concentration was also statistically significant (P<0.0001). Body mass index was positively related to plasma leptin concentration in both groups (P<0.0001).Conclusion:This Meta analysis approves increased level of leptin in spinal cord injured patients which can be due to fat distribution changes and sympathetic dysfunction in these patients. Our results also showed that patients with higher spinal lesion level have higher plasma leptin concentration. © 2013 International Spinal Cord Society All rights reserved
Smart and Multi-Functional Magnetic Nanoparticles for Cancer Treatment Applications: Clinical Challenges and Future Prospects
Iron oxide nanoparticle (IONPs) have become a subject of interest in various biomedical fields due to their magnetism and biocompatibility. They can be utilized as heat mediators in magnetic hyperthermia (MHT) or as contrast media in magnetic resonance imaging (MRI), and ultrasound (US). In addition, their high drug-loading capacity enabled them to be therapeutic agent transporters for malignancy treatment. Hence, smartening them allows for an intelligent controlled drug release (CDR) and targeted drug delivery (TDD). Smart magnetic nanoparticles (SMNPs) can overcome the impediments faced by classical chemo-treatment strategies, since they can be navigated and release drug via external or internal stimuli. Recently, they have been synchronized with other modalities, e.g., MRI, MHT, US, and for dual/multimodal theranostic applications in a single platform. Herein, we provide an overview of the attributes of MNPs for cancer theranostic application, fabrication procedures, surface coatings, targeting approaches, and recent advancement of SMNPs. Even though MNPs feature numerous privileges over chemotherapy agents, obstacles remain in clinical usage. This review in particular covers the clinical predicaments faced by SMNPs and future research scopes in the field of SMNPs for cancer theranostics
Exogenous WNT5A and WNT11 proteins rescue CITED2 dysfunction in mouse embryonic stem cells and zebrafish morphants
Mutations and inadequate methylation profiles of CITED2 are associated with human congenital heart disease (CHD). In mouse, Cited2 is necessary for embryogenesis, particularly for heart development, and its depletion in embryonic stem cells (ESC) impairs cardiac differentiation. We have now determined that Cited2 depletion in ESC affects the expression of transcription factors and cardiopoietic genes involved in early mesoderm and cardiac specification. Interestingly, the supplementation of the secretome prepared from ESC overexpressing CITED2, during the onset of differentiation, rescued the cardiogenic defects of Cited2-depleted ESC. In addition, we demonstrate that the proteins WNT5A and WNT11 held the potential for rescue. We also validated the zebrafish as a model to investigate cited2 function during development. Indeed, the microinjection of morpholinos targeting cited2 transcripts caused developmental defects recapitulating those of mice knockout models, including the increased propensity for cardiac defects and severe death rate. Importantly, the co-injection of anti-cited2 morpholinos with either CITED2 or WNT5A and WNT11 recombinant proteins corrected the developmental defects of Cited2-morphants. This study argues that defects caused by the dysfunction of Cited2 at early stages of development, including heart anomalies, may be remediable by supplementation of exogenous molecules, offering the opportunity to develop novel therapeutic strategies aiming to prevent CHD.Agência financiadora:
Fundação para a Ciência e a Tecnologia (FCT)
Comissão de Coordenação e Desenvolvimento Regional do Algarve (CCDR Algarve)
ALG-01-0145-FEDER-28044; DFG 568/17-2 Algarve Biomedical Center (ABC)
Municipio de Louléinfo:eu-repo/semantics/publishedVersio
Rate of Period Change as a Diagnostic of Cepheid Properties
Rate of period change for a Cepheid is shown to be a parameter that
is capable of indicating the instability strip crossing mode for individual
objects, and, in conjunction with light amplitude, likely location within the
instability strip. Observed rates of period change in over 200 Milky Way
Cepheids are demonstrated to be in general agreement with predictions from
stellar evolutionary models, although the sample also displays features that
are inconsistent with some published models and indicative of the importance of
additional factors not fully incorporated in models to date.Comment: Published in PASP (March 2006); TeX source & figures now provide
NASCaps: A Framework for Neural Architecture Search to Optimize the Accuracy and Hardware Efficiency of Convolutional Capsule Networks
Deep Neural Networks (DNNs) have made significant improvements to reach the
desired accuracy to be employed in a wide variety of Machine Learning (ML)
applications. Recently the Google Brain's team demonstrated the ability of
Capsule Networks (CapsNets) to encode and learn spatial correlations between
different input features, thereby obtaining superior learning capabilities
compared to traditional (i.e., non-capsule based) DNNs. However, designing
CapsNets using conventional methods is a tedious job and incurs significant
training effort. Recent studies have shown that powerful methods to
automatically select the best/optimal DNN model configuration for a given set
of applications and a training dataset are based on the Neural Architecture
Search (NAS) algorithms. Moreover, due to their extreme computational and
memory requirements, DNNs are employed using the specialized hardware
accelerators in IoT-Edge/CPS devices. In this paper, we propose NASCaps, an
automated framework for the hardware-aware NAS of different types of DNNs,
covering both traditional convolutional DNNs and CapsNets. We study the
efficacy of deploying a multi-objective Genetic Algorithm (e.g., based on the
NSGA-II algorithm). The proposed framework can jointly optimize the network
accuracy and the corresponding hardware efficiency, expressed in terms of
energy, memory, and latency of a given hardware accelerator executing the DNN
inference. Besides supporting the traditional DNN layers, our framework is the
first to model and supports the specialized capsule layers and dynamic routing
in the NAS-flow. We evaluate our framework on different datasets, generating
different network configurations, and demonstrate the tradeoffs between the
different output metrics. We will open-source the complete framework and
configurations of the Pareto-optimal architectures at
https://github.com/ehw-fit/nascaps.Comment: To appear at the IEEE/ACM International Conference on Computer-Aided
Design (ICCAD '20), November 2-5, 2020, Virtual Event, US
Ampelisca lusitanica (Crustacea: Amphipoda): new species for the Atlantic coast of Morocco
Background
This study reports for the first time the presence of the Lusitanian ampeliscid amphipod Ampelisca lusitanica Bellan-Santini & Marques, 1986 in the northwestern Atlantic coast of Morocco.
Methods
Specimens were collected in January 2015 from intertidal rock pools along the El Jadida shoreline associated with the brown algae Bifurcaria bifurcata and Sargassum muticum.
Results
Systematic description of the species is presented, as well as a discussion of its ecological and geographical distribution.
Conclusion
This new finding extends the geographical distribution from the Lusitanian (Europe) to the Mauritanian (Africa) region and increases knowledge of the ecology and the global distribution of A. lusitanica found, previously, only on Portuguese and Spanish coasts.info:eu-repo/semantics/publishedVersio
Does Collinder 236 host a Cepheid calibrator?
Photoelectric UBV photometry and star counts are presented for the previously
unstudied open cluster Collinder 236, supplemented by observations for stars
near the Cepheid WZ Car. Collinder 236 is typical of groups associated with
Cepheids, with an evolutionary age of (3.4+-1.1)x10^7 years, but it is 1944+-71
pc distant, only half the predicted distance to WZ Car. The cluster is reddened
by E(B-V)~0.26, and has nuclear and coronal radii of rn~2 arcmin (1.1 pc) and
Rc~8 arcmin (4.5 pc), respectively. The Cepheid is not a member of Collinder
236 on the basis of location beyond the cluster tidal radius and implied
distance, but its space reddening can be established as E(B-V)=0.268+-0.006
s.e. from 5 adjacent stars. Period changes in WZ Car studied with the aid of
archival data are revised. The period of WZ Car is increasing, its rate of
+8.27+-0.19 s yr^(-1) being consistent with a third crossing of the instability
strip.Comment: Accepted for publication (MNRAS
Inter-scan reproducibility of coronary calcium measurement using Multi Detector-Row Computed Tomography (MDCT)
Purpose: To assess inter-scan reproducibility of coronary calcium measurements obtained from Multi Detector-Row CT (MDCT) images and to evaluate whether this reproducibility is affected by different measurement protocols, slice thickness, cardiovascular risk factors and/or technical variables.
Design: Cross-sectional study with repeated measurements.
Materials and methods: The study population comprised 76 healthy women. Coronary calcium was assessed in these women twice in one session using 16-MDCT (Philips Mx 8000 IDT 16). Images were reconstructed with 1.5 mm slice thickness and 3.0 mm slice thickness. The 76 repeated scans were scored. The Agatston score, a volume measurement and a mass measurement were assessed. Reproducibility was determined by estimation of mean, absolute, relative difference, the weighted kappa value for agreement and the Intra-class correlation coefficient (ICCC).
Results: Fifty-five participants (72.4%) had a coronary calcification of more than zero in Agatston (1.5 mm slice thickness). The reproducibility of coronary calcium measurements between scans in terms of ranking was excellent with Intra-class correlation coefficients of >0.98, and kappa values above 0.80. The absolute difference in calcium score between scans increased with increasing calcium levels, indicating that measurement error increases with increasing calcium levels. However, no relation was found between the mean difference in scores and calcium levels, indicating that the increase in measurement error is likely to result in random misclassification in calcium score. Reproducibility results were similar for 1.5 mm slices and for 3.0 mm slices, and equal for Agatston, volume and mass measurements.
Conclusion: Inter-scan reproducibilility of measurement of coronary calcium using images from MDCT is excellent, irrespective of slice thickness and type of calcium parameter
Sustained supplementation and monitored response with differing carotenoid formulations in early age-related macular degeneration
PURPOSE: To compare the impact of sustained supplementation using different macular carotenoid formulations on macular pigment (MP) and visual function in early age-related macular degeneration (AMD). PATIENTS AND METHODS: Sixty-seven subjects with early AMD were randomly assigned to: Group 1 (20 mg per day lutein (L), 0.86 mg per day zeaxanthin (Z); Ultra Lutein), Group 2 (10 mg per day meso-zeaxanthin (MZ), 10 mg per day L, 2 mg per day Z; Macushield; Macuhealth), Group 3 (17 mg per day MZ, 3 mg per day L, 2 mg per day Z). MP was measured using customised heterochromatic flicker photometry and visual function was assessed by measuring contrast sensitivity (CS) and best-corrected visual acuity (BCVA). AMD was graded using the Wisconsin Age-Related Maculopathy Grading System (AREDS 11-step severity scale). RESULTS: At 3 years, a significant increase in MP from baseline was observed in all groups at each eccentricity (P<0.05), except at 1.75° in Group 1 (P=0.160). Between 24 and 36 months, significant increases in MP at each eccentricity were seen in Group 3 (P<0.05 for all), and at 0.50° in Group 2 (P<0.05), whereas no significant increases were seen in Group 1 (P>0.05 for all). At 36 months, compared with baseline, the following significant improvements (P<0.05) in CS were observed: Group 2—1.2, 6, and 9.6 cycles per degree (c.p.d.); Group 1—15.15 c.p.d.; and Group 3—6, 9.6, and 15.15 c.p.d. No significant changes in BCVA, or progression to advanced AMD, were observed. CONCLUSION: In early AMD, MP can be augmented with a variety of supplements, although the inclusion of MZ may confer benefits in terms of panprofile augmentation and in terms of CS enhancement
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