2,056 research outputs found
Análise de risco em quatro sistemas de rotação de culturas para trigo, num período de dez anos, em Passo Fundo, RS.
Numerical analysis of deep-seated mass movements in the Magura Nappe; Flysch Belt of the Western Carpathians (Czech Republic)
Deep-seated slope failures are common features in the mountains of the Raca Unit, Magura Nappe of the Flysch Belt of Western Carpathians. Since they represent very complicated system, understanding of their evolution and triggers still remains unclear. We tried to provide a back-analysis of their development by using a finite difference code (FDM) of continua (Flac 4.0). We confirmed that such large mass movements could be triggered by water saturation of the bedrock in the three particular geological and geomorphic settings. Such situation could have been caused by heavy rainfalls in humid phases of the Holocene or permafrost melting in Late Glacial. The effects of faulting, very deep weathering of the bedrock, low geotechnical parameters of smectite-rich material and the local slope geometry have also been accounted for in numerical models, as well as the other triggering factors of slope instability. FDM modelled shear zones are in agreement with observations
Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen
We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na /Si and Al /Si abundance ratios at the source, 0.036 ±0.003 for Na /Si and 0.103 ±0.004 for Al /Si , are determined independent of cosmic ray propagation
Acinetobacter baumannii targets human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) for invasion of pneumocytes
Multidrug-resistant Acinetobacter baumannii is regarded as a life-threatening pathogen mainly associated with nosocomial and community-acquired pneumonia. Here, we show that A. baumannii can bind the human carcinoembryonic antigen- related cell adhesion molecule (CEACAM) receptors CEACAM1, CEACAM5, and CEACAM6. This specific interaction enhances A. baumannii internalization in membrane- bound vacuoles, promptly decorated with Rab5, Rab7, and lipidated microtubule- associated protein light chain 3 (LC3). Dissecting intracellular signaling pathways revealed that infected pneumocytes trigger interleukin-8 (IL-8) secretion via the extracellular signal-regulated kinase (ERK)1/2 and nuclear factor-kappa B (NF-κB) signaling pathways for A. baumannii clearance. However, in CEACAM1-L-expressing cells, IL-8 secretion lasts only 24 h, possibly due to an A. baumannii-dependent effect on the CEACAM1-L intracellular domain. Conversely, the glycosylphosphatidylinositol- anchored CEACAM5 and CEACAM6 activate the c-Jun NH2-terminal kinase (JNK)1/ 2-Rubicon-NOX2 pathway, suggestive of LC3-associated phagocytosis. Overall, our data show for the first time novel mechanisms of adhesion to and invasion of pneumocytes by A. baumannii via CEACAM-dependent signaling pathways that eventually lead to bacterial killing. These findings suggest that CEACAM upregulation could put patients at increased risk of lower respiratory tract infection by A. baumannii. IMPORTANCE This work shows for the first time that Acinetobacter baumannii binds to carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), CEACAM5, and CEACAM6. This binding significantly enhances A. baumannii internalization within alveolar host cell epithelia. Intracellular trafficking involves typical Rab5 and Rab7 vacuolar proteins as well as light chain 3 (LC3) and slowly progresses to bacterial killing by endosome acidification. CEACAM engagement by A. baumannii leads to distinct and specific downstream signaling pathways. The CEACAM1 pathway finely tunes interleukin- 8 (IL-8) secretion, whereas CEACAM5 and CEACAM6 mediate LC3-associated phagocytosis. The present study provides new insights into A. baumannii-host interactions and could represent a promising therapeutic strategy to reduce pulmonary infections caused by this pathogen
Percolation, Morphogenesis, and Burgers Dynamics in Blood Vessels Formation
Experiments of in vitro formation of blood vessels show that cells randomly
spread on a gel matrix autonomously organize to form a connected vascular
network. We propose a simple model which reproduces many features of the
biological system. We show that both the model and the real system exhibit a
fractal behavior at small scales, due to the process of migration and dynamical
aggregation, followed at large scale by a random percolation behavior due to
the coalescence of aggregates. The results are in good agreement with the
analysis performed on the experimental data.Comment: 4 pages, 11 eps figure
A simple mechanistic model of sprout spacing in tumour-associated angiogenesis
This paper develops a simple mathematical model of the siting of capillary sprouts on an existing blood vessel during the initiation of tumour-induced angiogenesis. The model represents an inceptive attempt to address the question of how unchecked sprouting of the parent vessel is avoided at the initiation of angiogenesis, based on the idea that feedback regulation processes play the dominant role. No chemical interaction between the proangiogenic and antiangiogenic factors is assumed. The model is based on corneal pocket experiments, and provides a mathematical analysis of the initial spacing of angiogenic sprouts
Penetrating particle ANalyzer (PAN)
PAN is a scientific instrument suitable for deep space and interplanetary
missions. It can precisely measure and monitor the flux, composition, and
direction of highly penetrating particles (100 MeV/nucleon) in deep
space, over at least one full solar cycle (~11 years). The science program of
PAN is multi- and cross-disciplinary, covering cosmic ray physics, solar
physics, space weather and space travel. PAN will fill an observation gap of
galactic cosmic rays in the GeV region, and provide precise information of the
spectrum, composition and emission time of energetic particle originated from
the Sun. The precise measurement and monitoring of the energetic particles is
also a unique contribution to space weather studies. PAN will map the flux and
composition of penetrating particles, which cannot be shielded effectively,
precisely and continuously, providing valuable input for the assessment of the
related health risk, and for the development of an adequate mitigation
strategy. PAN has the potential to become a standard on-board instrument for
deep space human travel.
PAN is based on the proven detection principle of a magnetic spectrometer,
but with novel layout and detection concept. It will adopt advanced particle
detection technologies and industrial processes optimized for deep space
application. The device will require limited mass (~20 kg) and power (~20 W)
budget. Dipole magnet sectors built from high field permanent magnet Halbach
arrays, instrumented in a modular fashion with high resolution silicon strip
detectors, allow to reach an energy resolution better than 10\% for nuclei from
H to Fe at 1 GeV/n
A Scintillating Fiber Tracker With SiPM Readout
We present a prototype for the first tracking detector consisting of 250
micron thin scintillating fibers and silicon photomultiplier (SiPM) arrays. The
detector has a modular design, each module consists of a mechanical support
structure of 10mm Rohacell foam between two 100 micron thin carbon fiber skins.
Five layers of scintillating fibers are glued to both top and bottom of the
support structure. SiPM arrays with a channel pitch of 250 micron are placed in
front of the fibers. We show the results of the first module prototype using
multiclad fibers of types Bicron BCF-20 and Kuraray SCSF-81M that were read out
by novel 32-channel SiPM arrays from FBK-irst/INFN Perugia as well as
32-channel SiPM arrays produced by Hamamatsu. A spatial resolution of 88 micron
+/- 6 micron at an average yield of 10 detected photons per minimal ionizig
particle has been achieved.Comment: 5 pages, 7 figures, submitted as proceedings to the 11th Topical
Seminar on Innovative Particle and Radiation Detectors (IPRD08
Inactive Residents Living in Nursing Homes and Associated Predictors: Findings From a Regional-Based, Italian Retrospective Study.
Objectives: It has been amply reported that nursing home (NH) residents are largely inactive, a condition that may further increase functional decline, behavioral disorders, and risk of death. To date, studies have mainly focused on individual characteristics that may decrease residents' involvement in activities. Therefore, the aim of this study is to describe the prevalence of inactive NH residents in an Italian context, identifying predictors of inactivity at the individual and NH levels. Design: Retrospective regional-based study performed in 2014. Setting: All NHs (n = 105) located in the Friuli Venezia Giulia Region, northeastern region of Italy. Participants: A total of 8875 residents with at least 1 nursing assessment and living in an NH for at least 1 year. Measurements: The dependent variable was inactivity in the last week, defined as the resident not being involved in any socially or individually based, or meaningful recreational (eg, gardening) activities. The independent variables were set at individual and NH levels. Aiming at identifying predictors of inactivity, a hierarchical generalized linear (mixed-effects) model incorporating both fixed-effect parameters and random effects, was performed. Results: A total of 4042 (45.6%) residents were inactive during the week before the evaluation. At the resident level, those with severe cognitive impairment [odds (OR) 4.462, 95% confidence interval (CI) 3.880-5.132], unsociable behavior (OR 2.961, 95% CI 2.522-3.473), night restlessness (OR 1.605, 95% CI 1.395-1.853), lack of cooperation in daily care (OR 1.408, 95% CI 1.199-1.643), pressure sores (OR 1.314, 95% CI 1.065-1.622), depressive disorders (OR 1.242, 95% CI 1.089-1.416), and clinical instability (OR 1.110, 95% CI 1.037-1.188) reported an increased risk of being inactive. At the NH level, for each additional hour of care offered by professional educators, there was 1% less likelihood of inactive residents (OR .964, 95% .933-.996). Conclusions: Approximately one-half of the residents in this study living in Italian NHs are inactive. Inactivity is significantly associated with the presence of severe cognitive impairment, behavioral disorders (eg, unsociability, night restlessness, and lack of cooperation in daily care), pressure sores, depressive symptoms, and clinical instability. Moreover, receiving care from professional educators whose aim in their training program and professional mission is to improve individual and social engagement, decreased the likelihood of resident inactivity. \ua9 2016 AMDA - The Society for Post-Acute and Long-Term Care Medicine
Evaluation of a biosensor for phenolic compounds based on a nanostructured conducting polymer [PTu61].
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