199 research outputs found
Analysis of Energy Consumption Performance towards Optimal Radioplanning of Wireless Sensor Networks in Heterogeneous Indoor Environments
In this paper the impact of complex indoor environment in the deployment and energy consumption of a wireless sensor network infrastructure is analyzed. The variable nature of the radio channel is analyzed by means of deterministic in-house 3D ray launching simulation of an indoor scenario, in which wireless sensors, based on an in-house CyFi implementation, typically used for environmental monitoring, are located. Received signal power and current consumption measurement results of the in-house designed wireless motes have been obtained, stating that adequate consideration of the network topology and morphology lead to optimal performance and power consumption reduction. The use of radioplanning techniques therefore aid in the deployment of more energy efficient elements, optimizing the overall performance of the variety of deployed wireless systems within the indoor scenario
Relationship Between Mitochondrial Structure and Bioenergetics in Pseudoxanthoma elasticum Dermal Fibroblasts
Pseudoxanthoma elasticum (PXE) is a genetic disease considered as a paradigm of ectopic mineralization disorders, being characterized by multisystem clinical manifestations due to progressive calcification of skin, eyes, and the cardiovascular system, resembling an age-related phenotype. Although fibroblasts do not express the pathogenic ABCC6 gene, nevertheless these cells are still under investigation because they regulate connective tissue homeostasis, generating the âarenaâ where cells and extracellular matrix components can promote pathologic calcification and where activation of pro-osteogenic factors can be associated to pathways involving mitochondrial metabolism. The aim of the present study was to integrate structural and bioenergenetic features to deeply investigate mitochondria from control and from PXE fibroblasts cultured in standard conditions and to explore the role of mitochondria in the development of the PXE fibroblastsâ pathologic phenotype. Proteomic, biochemical, and morphological data provide new evidence that in basal culture conditions (1) the protein profile of PXE mitochondria reveals a number of differentially expressed proteins, suggesting changes in redox balance, oxidative phosphorylation, and calcium homeostasis in addition to modified structure and organization, (2) measure of oxygen consumption indicates that the PXE mitochondria have a low ability to cope with a sudden increased need for ATP via oxidative phosphorylation, (3) mitochondrial membranes are highly polarized in PXE fibroblasts, and this condition contributes to increased reactive oxygen species levels, (4) ultrastructural alterations in PXE mitochondria are associated with functional changes, and (5) PXE fibroblasts exhibit a more abundant, branched, and interconnected mitochondrial network compared to control cells, indicating that fusion prevail over fission events. In summary, the present study demonstrates that mitochondria are modified in PXE fibroblasts. Since mitochondria are key players in the development of the aging process, fibroblasts cultured from aged individuals or aged in vitro are more prone to calcify, and in PXE, calcified tissues remind features of premature aging syndromes; it can be hypothesized that mitochondria represent a common link contributing to the development of ectopic calcification in aging and in diseases. Therefore, ameliorating mitochondrial functions and cell metabolism could open new strategies to positively regulate a number of signaling pathways associated to pathologic calcification
Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase
Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force
output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of
body mass (Bm)) on sprint performance and force production during the acceleration phase. Twenty-three young
experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ±
1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg) performed four 30 m sprints from a crouch start. Sprint times in 20 and 30
m sprint, peak force (Fpeak), a peak rate of force development (RFDpeak) and time to RFD (TRFD) in first step were
recorded. Repeated-measures ANOVA showed significant increases (p †0.001) in sprint times (20 and 30 m sprint) for
each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load
increased (3129.4 ± 894.6 N·s-1, p †0.05 and 3892.4 ± 1377.9 N·s-1, p †0.01). Otherwise, no significant increases
were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle
contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up
to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and
thus, early acceleration.Actividad FĂsica y Deport
Role of Epidermal Growth Factor Receptor (EGFR) and Its Ligands in Kidney Inflammation and Damage
Chronickidneydisease (CKD)ischaracterized bypersistent inïŹammationandprogressive ïŹbrosis,ultimatelyleadingto end-stage renal disease. Although many studies have investigated the factors involved in the progressive deterioration of renal function, current therapeutic strategies only delay disease progression, leaving an unmet need for eïŹective therapeutic interventions that target the cause behind the inïŹammatory process and could slow down or reverse the development and progression of CKD. Epidermal growth factor receptor (EGFR) (ERBB1), a membrane tyrosine kinase receptor expressed in the kidney, is activated after renal damage, and preclinical studies have evidenced its potential as a therapeutic target in CKD therapy. To date, seven oïŹcial EGFR ligands have been described, including epidermal growth factor (EGF) (canonical ligand), transforming growth factor-α, heparin-binding epidermal growth factor, amphiregulin, betacellulin, epiregulin, and epigen. Recently, the connective tissue growth factor (CTGF/CCN2) has been described as a novel EGFR ligand. The direct activation of EGFR by its ligands can exert diïŹerent cellular responses, depending on the speciïŹc ligand, tissue, and pathological condition. Among all EGFR ligands, CTGF/CCN2 is of special relevance in CKD. This growth factor, by binding to EGFR and downstream signaling pathway activation, regulates renal inïŹammation, cell growth, and ïŹbrosis. EGFR can also be âtransactivatedâ by extracellular stimuli, including several key factors involved in renal disease, such as angiotensin II, transforming growth factor beta (TGFB), and other cytokines, including members of the tumor necrosis factor superfamily, showing another important mechanism involved in renal pathology. The aim of this review is to summarize the contribution of EGFR pathway activation in experimental kidney damage, with special attention to the regulation of the inïŹammatory response and the role of some EGFR ligands in this process. Better insights in EGFR signaling in renal disease could improve our current knowledge of renal pathology contributing to therapeutic strategies for CKD development and progression.This work was supported by the Instituto de Salud Carlos III and Fondos FEDER European Union (PI014/00041, PI17/00119), Red de InvestigaciĂłn Renal (REDinREN; RD16/0009), Comunidad de Madrid (B2017/BMD-3751 NOVELREN-CM), and Sociedad Española de NefrologĂa. The âJuan de la Cierva de Formacionâ training program of the Ministerio de EconomĂa, Industria y Competitividad, Gobierno de España supported the salary of SR-M (FJCI-2016-29050)
Epigenetic Modification Mechanisms Involved in Inflammation and Fibrosis in Renal Pathology
The growing incidence of obesity, hypertension, and diabetes, coupled with the aging of the population, is increasing the prevalence of renal diseases in our society. Chronic kidney disease (CKD) is characterized by persistent inflammation, fibrosis, and loss of renal function leading to end-stage renal disease. Nowadays, CKD treatment has limited effectiveness underscoring the importance of the development of innovative therapeutic options. Recent studies have identified how epigenetic modifications participate in the susceptibility to CKD and have explained how the environment interacts with the renal cell epigenome to contribute to renal damage. Epigenetic mechanisms regulate critical processes involved in gene regulation and downstream cellular responses. The most relevant epigenetic modifications that play a critical role in renal damage include DNA methylation, histone modifications, and changes in miRNA levels. Importantly, these epigenetic modifications are reversible and, therefore, a source of potential therapeutic targets. Here, we will explain how epigenetic mechanisms may regulate essential processes involved in renal pathology and highlight some possible epigenetic therapeutic strategies for CKD treatment.This work was supported by Instituto de Salud Carlos III and Fondos FEDER European Union (PI14/00041, PI15/00960, PI16/01354, PI17/00119, and PI17/01244), Red de InvestigaciĂłn Renal (REDinREN; RD16/0009), Comunidad de Madrid (B2017/BMD-3751 NOVELREN-CM), Fondecyt 1181574 (BK), Sociedad Española de NefrologĂa, and the âJuan de la Cierva Formacionâ training program of the Ministerio de Economia, Industria y Competitividad which supported the salary of S.R-M (FJCI-2016-29050). V. Marchant has a CONICYT Scholarship for his graduate studies at the PhD program in Medical Science, Universidad Austral de Chile. The Centro de Estudios CientĂïŹcos is funded by the Chilean Government through the Centers of Excellence Basal Financing Program of CONICYT
Proper motions of cool and ultracool candidate members in the Upper Scorpius OB association
Proper motion measurements of the cool and ultracool populations in the Upper
Scorpius OB association are crucial to confirm membership and to identify
possible run-away objects.
We cross-match samples of photometrically selected and spectroscopically
confirmed cool and ultracool (K5<SpT<M8.5) candidate members in the Upper
Scorpius OB association using the literature and the USNO-B and the UCAC2
catalogues. 251 of these objects have a USNO-B and/or UCAC2 counterpart with
proper motion measurements.
A significant fraction (19 objects, 7.6+-1.8%) of spectroscopically confirmed
young objects show discrepant proper motion. They must either belong to
unidentified coincident foreground associations, or originate from neighboring
star forming regions or have recently experienced dynamical interactions within
the association. The observed accretor and disc frequencies are lower among
outliers, but with only 19 objects it is unreliable to draw firm statistical
conclusions. Finally, we note that transverse velocities of very low mass
members are indistinguishable from those of low mass members within 4km/sComment: accepted for publication in A&
COVID-19 and Sick Leave: An Analysis of the Ibermutua Cohort of Over 1,651,305 Spanish Workers in the First Trimester of 2020
Objectives: The worldwide SARS-COV2 pandemic has impacted the health of workers and companies. The aim is to quantify it according to sick leave. Methods: Using ICD-9 codes, we analyzed Ibermutua records of all sick leaves during the first trimester of 2020, compared to during the same months of 2017, 2018, and 2019. We stratified the analysis by causes, patient sex, activity sectors, and regional data. All sick leaves were adjusted by the number of Ibermutua-affiliated persons in each period. Results: In March 2020, there was an unprecedented (116%) increase in total sick leaves, mainly due to infectious and respiratory diseases. Men and women were equally affected. All activity sectors were impacted, with the highest increase (457%) observed among health-related workers, especially due to contagious disease. The incidences of sick leaves were heterogeneous among different regions. Cost-analysis of sick leaves during the first trimester of 2020 compared with in previous years showed 40.3% increment (mean 2,813 vs. 2,005 euro per 100 affiliated workers). Conclusions: The SARS-COV2 pandemic is having a huge impact on workers' health, as shown by data regarding sick leaves in March 2020. This is associated with greater economic burden for companies, both due to the cost associated with sick leaves and the losses in productivity due to confinement
Low-resolution spectroscopy and spectral energy distributions of selected sources towards sigma Orionis
Aims: We investigated in detail nine sources in the direction of the young
sigma Orionis cluster, which is considered a unique site for studying stellar
and substellar formation. The nine sources were selected because of some
peculiar properties, such as extremely red infrared colours or too strong
Halpha emission for their blue optical colours. Methods: We took high-quality,
low-resolution spectroscopy (R ~ 500) of the nine targets with ALFOSC at the
Nordic Optical Telescope. We also re-analyzed [24]-band photometry from
MIPS/Spitzer and compiled the best photometry available at the ViJHKs passbands
and the four IRAC/Spitzer channels for constructing accurate spectral energy
distributions covering from 0.55 to 24 mum. Results: The nine targets were
classified into: one Herbig Ae/Be star with a scatterer edge-on disc, two
G-type stars, one X-ray flaring, early-M, young star with chromospheric Halpha
emission, one very low-mass, accreting, young spectroscopic binary, two young
objects at the brown dwarf boundary with the characteristics of classical T
Tauri stars, and two emission-line galaxies, one undergoing star formation, and
another one whose spectral energy distribution is dominated by an active
galactic nucleus. Besides, we discover three infrared sources associated to
overdensities in a cold cloud in the cluster centre. Conclusions:
Low-resolution spectroscopy and spectral energy distributions are a vital tool
for measuring the physical properties and the evolution of young stars and
candidates in the sigma Orionis cluster.Comment: Accepted for publication in A&
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