1,016 research outputs found
MONITORING THE URBAN GROWTH OF DHAKA (BANGLADESH) BY SATELLITE IMAGERY IN FLOODING RISK MANAGEMENT PERSPECTIVE
There is large consensus that demographic changes, the lack of appropriate environmental policies and sprawling urbanization result in high vulnerability and exposure to the natural disasters. This work reports some experiences of using multispectral satellite imagery to produce landuse/cover maps for the Dhaka city, the capital of Bangladesh, which is subject to frequent flooding events.The activity was conducted in collaboration with the non-profit organization ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The Landsat images acquired in 2000, 2002 and 2009 were used to evaluate the urban growth in order to support risk assessment studies; to identify areas routinely flooded during the monsoon season, the image of October 2009 (the most critical month for the effects of rain) was compared with two images acquired in January and February 2010. The analysis between 2000 and 2009 was able to quantify a very rapid growth of the metropolis, with an increase in built-up areas from 75 to 111 km2. The analysis highlights also a sharp rise of Bare soil class, likely related to the construction of embankments for the creation of new building space; consequently a decrease of cultivated land was observed. In particular, these artificial islands have been invading flooding areas. The change detection procedure also showed that the flooding in October 2009 affected about 20% (115 out of 591 km2) of the entire study area; furthermore these areas became wetlands and farmland over the next three/four months
Control Across Scales by Positive and Negative Feedback
Feedback is a key element of regulation, as it shapes the sensitivity of a process to its environment. Positive feedback upregulates, and negative feedback downregulates. Many regulatory processes involve a mixture of both, whether in nature or in engineering. This article revisits the mixed-feedback paradigm, with the aim of investigating control across scales. We propose that mixed feedback regulates excitability and that excitability plays a central role in multiscale neuronal signaling. We analyze this role in a multiscale network architecture inspired by neurophysiology. The nodal behavior defines a mesoscale that connects actuation at the microscale to regulation at the macroscale. We show that mixed-feedback nodal control provides regulatory principles at the network scale, with a nodal resolution. In this sense, the mixed-feedback paradigm is a control principle across scales. </jats:p
Sunscreens’ uv filters risk for coastal marine environment biodiversity: A review
Considering the rapid growth of tourism in recent years and the acknowledgement that exposure to solar UV radiation may cause skin cancer, sunscreens have been widely used by beach-goers in recent decades. UV filters contained in sunscreens, however, were recently identified as emerging pollutants in coastal waters since they accumulate in the marine environment with different adverse effects. In fact, exposure to these components was proven to be toxic to most invertebrate and vertebrate marine species. Some UV filters are linked to the production of significant amounts of reactive oxygen species (ROS), such as hydrogen peroxide, and the release of inorganic micronutrients that may alter the status of coastal habitats. Bioaccumulation and biomagnification have not yet been fully addressed. This review highlights recent progress in research and provides a comprehensive overview of the toxicological and ecotoxicological effects of the most used UV filters both on the abiotic and biotic compartments in different types of coastal areas, to gain a better understanding of the impacts on coastal biodiversity
Switchable slow cellular conductances determine robustness and tunability of network states.
Neuronal information processing is regulated by fast and localized fluctuations of brain states. Brain states reliably switch between distinct spatiotemporal signatures at a network scale even though they are composed of heterogeneous and variable rhythms at a cellular scale. We investigated the mechanisms of this network control in a conductance-based population model that reliably switches between active and oscillatory mean-fields. Robust control of the mean-field properties relies critically on a switchable negative intrinsic conductance at the cellular level. This conductance endows circuits with a shared cellular positive feedback that can switch population rhythms on and off at a cellular resolution. The switch is largely independent from other intrinsic neuronal properties, network size and synaptic connectivity. It is therefore compatible with the temporal variability and spatial heterogeneity induced by slower regulatory functions such as neuromodulation, synaptic plasticity and homeostasis. Strikingly, the required cellular mechanism is available in all cell types that possess T-type calcium channels but unavailable in computational models that neglect the slow kinetics of their activation
Neuronal behaviors: A control perspective
The purpose of this tutorial is to introduce and analyze models of neurons from a control perspective and to show how recently developed analytical tools help to address important biological questions. A first objective is to review the basic modeling principles of neurophysiology in which neurons are modeled as equivalent nonlinear electrical circuits that capture their excitable properties. The specific architecture of the models is key to the tractability of their analysis: in spite of their high-dimensional and nonlinear nature, the model properties can be understood in terms of few canonical positive and negative feedback motifs localized in distinct timescales. We use this insight to shed light on a key problem in experimental neurophysiology, the challenge of understanding the sensitivity of neuronal behaviors to underlying parameters in empirically-derived models. Finally, we show how sensitivity analysis of neuronal excitability relates to robustness and regulation of neuronal behaviors.This paper presents research results of the Belgian Network DYSCO (Dynamical Systems, Control, and Optimization), funded by the Interuniversity Attraction Poles Programme, initiated by the Belgian State, Science Policy Office. G.D. is a Marie-Curie COFUND postdoctoral fellow at the University of Liege. Co-funded by the European Union. J.D. is supported by the F.R.S.-FNRS (Belgian Fund for Scientific Research. The scientific responsibility rests with its authors.This is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1109/CDC.2015.740249
Cinta Senese and Large White x Cinta Senese raised on pasture in wood: sample join composition and meat quality
Effect of rearing system on body traits and fillet quality of meagre (Argyrosomus regius, Asso 1801) chilled for a short time
The purpose of this study was to evaluate qualitative traits of meagre (Argyrosomus regius) from two different rearing systems (land-based tank filled with geothermal water vs offshore sea cage) and after short-term storage at chilling temperature (1, 2, or 3 days). Fish originated from the same batch were fed the same diet. Morpho-biometric traits, L*, a*, and b* colour parameters, texture, free water, proximate composition, total lipids, fatty acids, iron, and selenium contents were analyzed in the fillets. Most parameters were affected by rearing system. Compared to tank-reared fish, caged fish were shorter, poorer in visceral fat, and had higher incidence in cavity content and liver, lower incidence in gonads and head. Caged fish also had softer fillets in the epaxial site, which showed a higher tendency towards greenish colour. Caged fish also showed higher lipid content but lower Fe and Se content. Tank-reared fish fillets were more abundant in PUFAn-3, mainly due to DHA (18.54 vs 12.95%; P<0.001) and consequently showed the best healthiness indexes. Minimal changes, mostly involving colour and texture, were detected during the first three days of refrigerated storage. During storage, no significant modification of the parameters investigated could be ascribed to the rearing system
Anemia correction by erythropoietin reduces BNP levels, hospitalization rate, and NYHA class in patients with cardio-renal anemia syndrome.
Little is known about the effect of anemia correction with erythropoietin (EPO)
on B-type natriuretic peptide (BNP) levels, NYHA class, and hospitalization rate.
The aim of the study was to investigate, in patients with cardio-renal anemia
syndrome, the effects of EPO on hemochrome and renal function parameters and BNP
levels. We also analyzed the effect of EPO therapy on hospitalization rate and
NYHA class after 12 months in comparison with a population undergoing to standard
therapy. We performed a randomized double-blind controlled study of correction of
the anemia with subcutaneous ? (group A n = 13) or ? (group B n = 14) EPO for 12
months in addition to standard therapy with oral iron in 27 subjects. Control
group (n = 25 patients) received only oral iron. Significant increase in
hemoglobin (Hb), hematocrit (Hct), and red blood cells (RBC) were revealed in EPO
groups at 12 months; Hb, group A 12.3 ± 0.6; group B 11.7 ± 0.8; control group
10.6 ± 0.5 g/dl P < 0.0001; Hct group A 34.2 ± 2.3, group B 34 ± 2, control group
32.3 ± 1.8% P < 0.01; RBC, group A 3.9 ± 0.2, group B 3.8 ± 0.2, control group
3.3 ± 0.2, (P < 0.0001). Plasma BNP levels in EPO groups were significantly
reduced after 12 months (group A: 335 ± 138 vs. group B: 449 ± 274 pg/ml control
group 582 ± 209 pg/ml (P < 0.01). After 12 months of treatment, hospitalization
rate and NYHA class were reduced in EPO groups with respect to control group (P <
0.05). Finally, an inverse correlation was observed between BNP and Hb levels in
EPO Groups (r = -0.70 P < 0.001). EPO treatment reduces BNP levels and
hospitalization rate in patients with cardio-renal anemia syndrome. The
correction of anemia by EPO treatment appears able to improve clinical outcome in
this subset of patients with heart failur
Continuous versus bolus intermittent loop diuretic infusion in acutely decompensated heart failure: a prospective randomized trial.
Intravenous loop diuretics are a cornerstone of therapy in acutely decompensated heart failure (ADHF). We sought to determine if there are any differences in clinical outcomes between intravenous bolus and continuous infusion of loop diuretics.Methods: Subjects with ADHF within 12 hours of hospital admission were randomly assigned to continuous infusion or twice daily bolus therapy with furosemide. There were three co-primary endpoints assessed from admission to discharge: the mean paired changes in serum creatinine, estimated glomerular filtration rate (eGFR), and reduction in B-type natriuretic peptide (BNP). Secondary endpoints included the rate of acute kidney injury (AKI), change in body weight and six months follow-up evaluation after discharge.Results: A total of 43 received a continuous infusion and 39 were assigned to bolus treatment. At discharge, the mean change in serum creatinine was higher (+0.8 ± 0.4 versus -0.8 ± 0.3 mg/dl P <0.01), and eGFR was lower (-9 ± 7 versus +5 ± 6 ml/min/1.73 m2P <0.05) in the continuous arm. There was no significant difference in the degree of weight loss (-4.1 ± 1.9 versus -3.5 ± 2.4 kg P = 0.23). The continuous infusion arm had a greater reduction in BNP over the hospital course, (-576 ± 655 versus -181 ± 527 pg/ml P = 0.02). The rates of AKI were comparable (22% and 15% P = 0.3) between the two groups. There was more frequent use of hypertonic saline solutions for hyponatremia (33% versus 18% P <0.01), intravenous dopamine infusions (35% versus 23% P = 0.02), and the hospital length of stay was longer in the continuous infusion group (14. 3 ± 5 versus 11.5 ± 4 days, P <0.03). At 6 months there were higher rates of re-admission or death in the continuous infusion group, 58% versus 23%, (P = 0.001) and this mode of treatment independently associated with this outcome after adjusting for baseline and intermediate variables (adjusted hazard ratio = 2.57, 95% confidence interval, 1.01 to 6.58 P = 0.04).Conclusions: In the setting of ADHF, continuous infusion of loop diuretics resulted in greater reductions in BNP from admission to discharge. However, this appeared to occur at the consequence of worsened renal filtration function, use of additional treatment, and higher rates of rehospitalization or death at six months
Engineering of janus-like dendrimers with peptides derived from glycoproteins of herpes simplex virus type 1: Toward a versatile and novel antiviral platform
Novel antiviral nanotherapeutics, which may inactivate the virus and block it from entering host cells, represent an important challenge to face viral global health emergencies around the world. Using a combination of bioorthogonal copper-catalyzed 1,3-dipolar alkyne/azide cycloaddition (CuAAC) and photoinitiated thiol–ene coupling, monofunctional and bifunctional peptidodendrimer conjugates were obtained. The conjugates are biocompatible and demonstrate no toxicity to cells at biologically relevant concentrations. Furthermore, the orthogonal addition of multiple copies of two different antiviral peptides on the surface of a single dendrimer allowed the resulting biocon-jugates to inhibit Herpes simplex virus type 1 at both the early and the late stages of the infection process. The presented work builds on further improving this attractive design to obtain a new class of therapeutics
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