360 research outputs found
Transforming Growth Factor-β-Induced Cell Plasticity in Liver Fibrosis and Hepatocarcinogenesis
The Transforming Growth Factor-beta (TGF-β) family plays relevant roles in the regulation of different cellular processes that are essential for tissue and organ homeostasis. In the case of the liver, TGF-β signaling participates in different stages of disease progression, from initial liver injury toward fibrosis, cirrhosis and cancer. When a chronic injury takes place, mobilization of lymphocytes and other inflammatory cells occur, thus setting the stage for persistence of an inflammatory response. Macrophages produce profibrotic mediators, among them, TGF-β, which is responsible for activation -transdifferentiation- of quiescent hepatic stellate cells (HSC) to a myofibroblast (MFB) phenotype. MFBs are the principal source of extracellular matrix protein (ECM) accumulation and prominent mediators of fibrogenesis. TGF-β also mediates an epithelial-mesenchymal transition (EMT) process in hepatocytes that may contribute, directly or indirectly, to increase the MFB population. In hepatocarcinogenesis, TGF-β plays a dual role, behaving as a suppressor factor at early stages, but contributing to later tumor progression, once cells escape from its cytostatic effects. As part of its potential pro-tumorigenic actions, TGF-β induces EMT in liver tumor cells, which increases its pro-migratory and invasive potential. In parallel, TGF-β also induces changes in tumor cell plasticity, conferring properties of a migratory tumor initiating cell (TIC). The main aim of this review is to shed light about the pleiotropic actions of TGF-β that explain its effects on the different liver cell populations. The cross-talk with other signaling pathways that contribute to TGF-β effects, in particular the Epidermal Growth Factor Receptor (EGFR), will be presented. Finally, we will discuss the rationale for targeting the TGF-β pathway in liver pathologies
A Real-Time Wireless Sensor Network for Wheelchair Navigation
Today, the availability of inexpensive, low power
hardware including CMOS cameras and wireless devices make
it possible to deploy a wireless sensor network (WSN) with nodes
equipped with cameras for a variety of applications. In this
paper, we discuss the use of one of these WSNs as a navigation
aid for wheelchairs. Instead of having complicated wheelchairs
with lots of on-board sensors, we argue that a viable alternative
is to have simpler wheelchairs that are able to interact with an
intelligent environment so that the wheelchair bases its
navigation on its software intelligence, supported by the
information sent by external sensors. Many questions have to be
investigated, for instance how sensors should be deployed or
whether the wireless links would be able to meet our temporal
requirements. We describe some of the solutions we adopted,
particularly how to implement with Zigbee devices a polling
mechanism that allows us to guarantee a real-time secure
navigation.Ministerio de Educación y Ciencia TIN2006-15617- C03-03Junta de Andalucía P06-TIC-229
Transforming growth factor-β-induced cell plasticity in liver fibrosis and hepatocarcinogenesis
The Transforming Growth Factor-beta (TGF-β) family plays relevant roles in the regulation of different cellular processes that are essential for tissue and organ homeostasis. In the case of the liver, TGF-β signaling participates in different stages of disease progression, from initial liver injury toward fibrosis, cirrhosis and cancer. When a chronic injury takes place, mobilization of lymphocytes and other inflammatory cells occur, thus setting the stage for persistence of an inflammatory response. Macrophages produce profibrotic mediators, among them, TGF-β, which is responsible for activation -transdifferentiation- of quiescent hepatic stellate cells (HSC) to a myofibroblast (MFB) phenotype. MFBs are the principal source of extracellular matrix protein (ECM) accumulation and prominent mediators of fibrogenesis. TGF-β also mediates an epithelial-mesenchymal transition (EMT) process in hepatocytes that may contribute, directly or indirectly, to increase the MFB population. In hepatocarcinogenesis, TGF-β plays a dual role, behaving as a suppressor factor at early stages, but contributing to later tumor progression, once cells escape from its cytostatic effects. As part of its potential pro-tumorigenic actions, TGF-β induces EMT in liver tumor cells, which increases its pro-migratory and invasive potential. In parallel, TGF-β also induces changes in tumor cell plasticity, conferring properties of a migratory tumor initiating cell (TIC). The main aim of this review is to shed light about the pleiotropic actions of TGF-β that explain its effects on the different liver cell populations. The cross-talk with other signaling pathways that contribute to TGF-β effects, in particular the Epidermal Growth Factor Receptor (EGFR), will be presented. Finally, we will discuss the rationale for targeting the TGF-β pathway in liver pathologies
Soft real-time communications over Bluetooth under interferences from ISM devices
Bluetooth is a suitable technology to support soft real-time applications like multimedia streams at the
personal area network level. In this paper, we analytically evaluate the worst-case deadline failure
probability of Bluetooth packets under co-channel interference as a way to provide statistical guarantees
when transmitting soft real-time traffic using ACL links. We consider the interference from independent
Bluetooth devices, as well as from other devices operating in the ISM band like 802.11b/g and Zigbee.
Finally, we show as an example how to use our model to obtain some results for the transmission of a voice
stream.Ministerio de Ciencia y Tecnología TIC2001-1868-C03-0
Experimental evaluation of flexible duplexing in multi-tier MIMO networks
In this paper, we present an experimental evaluation of the performance benefits provided by flexible duplexing, an access technique that allows uplink and downlink cells to coexist within the same time-frequency resource blocks. In order to replicate a wireless multi-tier network composed of 1 macro-cell and 2 small cells, a measurement campaign has been conducted using an indoor wireless testbed comprised of a total of 6 multiple-input multiple-output (MIMO) software-defined radio (SDR) devices. Since each cell has a single active user, each uplink/downlink configuration can be identified with a different interference channel, over which interference alignment (IA) is used as an inter-cell interference management technique and compared to other existing methods. The obtained results show that flexible duplexing clearly outperforms the conventional time-division duplex (TDD) access approach, where all cells operate synchronized either in uplink or dowlink mode. Additionally, interference alignment consistently provides better results in most of the interference regimes when compared to minimum means quare error (MMSE)-based schemes. The impact of channel estimate quality on the different communication strategies is also studied. It is worth highlighting that the presented over-the-air (OTA) experiments represent the first implementation of IA with real-time precoding and decoding.The work of Jacobo Fanjul, Jesús Ibáñez and Ignacio Santamaria has been supported by the Ministerio de Economía, Industria y Competitividad (MINECO) of Spain, and AEI/FEDER funds of the E.U., under grant TEC2016-75067-C4-4-R (CARMEN), grant PID2019-104958RB-C43 (ADELE), and FPI grant BES-2014-069786. The work of José A. García-Naya has been funded by the Xunta de Galicia (ED431G2019/01), the Agencia Estatal de Investigación of Spain (TEC2016-75067-C4-1-R, RED2018-102668-T), and ERDF funds of the E.U. (AEI/FEDER, UE)
Residual cyst with semisolid content, a clinical case.
Objective: to present a clinical case of a residual cyst in the right maxillary region with semi- solid content. Main data of the case: 61-year-old patient who comes to consultation for the realization of up- per jaw dentures, during the clinical examination a slight facial asymmetry of the right side is observed; radiographic and tomographic examination revealed a radiolucent lesion in the right premolar region. It is diagnosed as a residual cyst and an enucleation is decided; during the surgical procedure a viscous content of yellowish coloration and semi-solid content is observed. Main comments: it is very rare to find residual cysts with semi-solid content, since they gene- rally have purulent or serosanguinous contents
A Dynamic Equilibrium View of Caching Systems
In this paper, we present a simple analytical study of
caching systems based on the idea of dynamic equilibrium of
cache blocks, assuming the Independent Reference Model (IRM)
of references. This method allows us to obtain simple closedform
expressions for parameters that are usually excluded from
cache studies, such as the mean number of reads or writes per
cache block while in the cache. We finally present some
simulation results in order to validate the analysis.Ministerio de Educación y Ciencia TIN2006-15617- C03-03Junta de Andalucía P06-TIC-229
Star-formation histories of local luminous infrared galaxies
We present the analysis of the integrated spectral energy distribution (SED)
from the ultraviolet (UV) to the far-infrared and H of a sample of 29
local systems and individual galaxies with infrared (IR) luminosities between
10^11 Lsun and 10^11.8 Lsun. We have combined new narrow-band H+[NII]
and broad-band g, r optical imaging taken with the Nordic Optical Telescope
(NOT), with archival GALEX, 2MASS, Spitzer, and Herschel data. The SEDs
(photometry and integrated H flux) have been fitted with a modified
version of the MAGPHYS code using stellar population synthesis models for the
UV-near-IR range and thermal emission models for the IR emission taking into
account the energy balance between the absorbed and re-emitted radiation. From
the SED fits we derive the star-formation histories (SFH) of these galaxies.
For nearly half of them the star-formation rate appears to be approximately
constant during the last few Gyrs. In the other half, the current
star-formation rate seems to be enhanced by a factor of 3-20 with respect to
that occured ~1 Gyr ago. Objects with constant SFH tend to be more massive than
starbursts and they are compatible with the expected properties of a
main-sequence (M-S) galaxy. Likewise, the derived SFHs show that all our
objects were M-S galaxies ~1 Gyr ago with stellar masses between 10^10.1 and
10^11.5 Msun. We also derived from our fits the average extinction (A_v=0.6-3
mag) and the polycyclic aromatic hydrocarbons (PAH) luminosity to L(IR) ratio
(0.03-0.16). We combined the A_v with the total IR and H luminosities
into a diagram which can be used to identify objects with rapidly changing
(increasing or decreasing) SFR during the last 100 Myr.Comment: 16 pages + online material, accepted for publication in A&
Glioma Diagnosis Aid through CNNs and Fuzzy-C Means for MRI
Glioma is a type of brain tumor that causes mortality in many cases. Early diagnosis is an important factor.
Typically, it is detected through MRI and then either a treatment is applied, or it is removed through surgery.
Deep-learning techniques are becoming popular in medical applications and image-based diagnosis.
Convolutional Neural Networks are the preferred architecture for object detection and classification in images.
In this paper, we present a study to evaluate the efficiency of using CNNs for diagnosis aids in glioma
detection and the improvement of the method when using a clustering method (Fuzzy C-means) for preprocessing
the input MRI dataset. Results offered an accuracy improvement from 0.77 to 0.81 when using
Fuzzy C-Means.Ministerio de Economía y Competitividad TEC2016-77785-
An analytical model of inter-channel interference in Bluetooth-based systems
One of the main advantages of the Bluetooth standard is that it provides a way to support ad-hoc connectivity between a variable number of devices at low cost. However, in situations with many Bluetooth devices that coexist in the same area the problem of channel interference may become of high importance. In this paper, we present an analysis that provides some expressions for the channel throughput and the delay that packets suffer due to possible collisions with other Bluetooth devices. The model includes the different effects of new and retransmitted packets. Both synchronized and unsynchronized systems are considered. Furthermore, although the effect of propagation losses are not explicitly considered, we show how they could be included in our model.Ministerio de Ciencia y Tecnología TIC2001-1868-C03-02Ministerio de Ciencia y Tecnología TIC2000-0087-P4-0
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