We consider
C
r
(
r
⩾
1
) diffeomorphisms
f
defined on manifolds of dimension
⩾
3
with homoclinic tangencies associated to saddles. Under generic properties, we show that if the saddle is ...homoclinically related to a blender then the diffeomorphism
f
can be
C
r
approximated by diffeomorphisms with
C
1
robust heterodimensional cycles. As an application, we show that the classic Simon–Asaoka’s examples of diffeomorphisms with
C
1
robust homoclinic tangencies also display
C
1
robust heterodimensional cycles. In a second application, we consider homoclinic tangencies associated to hyperbolic sets. When the entropy of these sets is large enough we obtain
C
1
robust cycles after
C
1
perturbations.
In this work, the occurrence of microplastics (MPs) in irrigation recycled wastewaters (RWWs) and a desalinated brackish water (DBW) from the arid territory of Fuerteventura (Canary Islands, Spain) ...was studied. Besides, the presence of MPs in two types of soils (sandy-loam and clay-loamy; with no mulch film or fertilization with sewage sludge applied) irrigated with both water qualities was addressed. Results showed the prevalence presence of cellulosic and polyester microfibers (between 84.4 and 100%) of blue and transparent colors (up to 55.6 and 33.3%, respectively), with an average length of 786.9 ± 812.1 μm in the water samples. DBW had the lowest MP concentration (2.0 ± 2.0 items·L−1) while RWW showed concentrations up to 40.0 ± 19.0 items·L−1. Similarities were also observed between the MPs types and sizes found in both soils top layer (0–5 cm), with an average concentration three times greater in soil irrigated with RWW than in soil under DBW irrigation (159 ± 338 vs. 46 ± 92 items·kg−1, respectively). In addition, no MPs were extracted from non-irrigated/non-cultivated soils, suggesting agricultural activities as the unique source of MPs in soils of this arid area. Results show that RWWs constitute a potential source of MPs in irrigated soils that should be considered among other pros and cons linked to the use of this water quality in agricultural arid lands.
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•Microplastics occurrence in irrigation waters and soils irrigated with them was accomplished.•Prevalence of cellulosic and polyester blue and transparent microfibers was found.•Similar microplastics patterns (shapes, colors and composition) were found between waters and soils.•Desalinated brackish water and the soil irrigated with it contained less microplastics.
Abstract Background Induction therapy for simultaneous pancreas-kidney (SPK) transplantation. Both thymoglobulin (ATG) and basiliximab are the most-used types of induction antibodies therapies in ...clinical practice. The aim of our report was to analyze our experience comparing 2 induction therapies, for SPK transplantation in terms of pancreas and patient survival, as well as rejection rate. Methods We reviewed retrospectively a total of 97 SPK transplantations in our institution. The cases were divided according to induction therapy in 2 groups, basiliximab (n = 38) and ATG (n = 59). Rejection, patient and graft survival, and postoperative complications were analyzed. Results Survival in the ATG group was better without statistical difference at 1-, 3-, and 5-year follow-up (97%, 95%, and 95% versus 92%, 90%, and 87%, respectively). No difference was detected in pancreas graft survival after 1-, 3-, and 5-year follow-up (basiliximab 85%, 80%, and 77% versus ATG 84%, 84%, and 81%, respectively; log-rank, 0.847). Overall cellular rejection and early rejection were more common in the basiliximab group (30 versus 14%, and 21% versus 6%). In the multivariate analysis considering human leukocyte antigen (HLA) mismatches, the ATG group was a protective factor for cellular rejection. Major complications (Grade III-IV) and median length of the hospital stay were higher in the basiliximab group (55% versus 34%, P = .057, and 21 versus 16 days, P = .056). Conclusions The pancreas graft survival was not affected by induction therapy. ATG induction therapy compared with basiliximab is associated with lower overall and early rejection rate. Over time this difference disappears.
•Three dimensional laminar MDH flow in an open annular channel.•Quasi-analytical solution for velocity profile and flow rate.•The maximum experimental velocity is determined using Particle Image ...Velocimetry.•The flow rate is maximized when the radii ratio is about fifteen percent.
In this paper, we research theoretically and experimentally the 3D laminar flow of an electrolyte in an annular open channel driven by a Lorentz force. The annular duct is formed by two concentric electrically conducting cylinders and limited by an insulating bottom wall. The interaction between a uniform magnetic field along the axial direction and a radial electric current produces a Lorentz force that drives the fluid in the azimuthal direction, producing a Magnetohydrodynamic (MHD) flow. The effect of the three walls is analyzed in detail by considering the gap between the cylinders as well as the depth of the channel. The steady flow is solved using a Galërkin method with orthogonal Bessel-Fourier series. A quasi-analytic approximation for velocity is found. Velocity profiles are explored by varying the depth of the channel and the gap between the cylinders in order to show the effect of the walls on the flow configuration. Results are compared with experimental data provided by PIV technique as well as in those found in scientific literature.
Trajectory optimization has recently been addressed to compute energy-efficient routes for ornithopter navigation, but its online application remains a challenge. To overcome the high computation ...time of traditional approaches, this paper proposes algorithms that recursively generate trajectories based on the output of neural networks and random forest. To this end, we create a large data set composed by energy-efficient trajectories obtained by running a competitive planner. To the best of our knowledge our proposed data set is the first one with a high number of pseudo-optimal paths for ornithopter trajectory optimization. We compare the performance of three methods to compute low-cost trajectories: two classification approaches to learn maneuvers and an alternative regression method that predicts new states. The algorithms are tested in several scenarios, including the landing case. The effectiveness and efficiency of the proposed algorithms are demonstrated through simulation, which show that the machine learning techniques can be used to compute the flight path of the ornithopter in real time, even under uncertainties such as wrong sensor readings or re-positioning of the target. Random Forest obtains the higher performance with more than 99% and 97% of accuracy in a landing and a mid-range scenario, respectively.
Locating a single facility and a high-speed line Díaz-Báñez, J.M.; Korman, M.; Pérez-Lantero, P. ...
European journal of operational research,
07/2014, Letnik:
236, Številka:
1
Journal Article
Recenzirano
Odprti dostop
•We study a highway and facility location problem.•We give a characterization of the optimal solution.•Type of solution depends on the highway’s speed.•We provide O(n3) algorithms that work in both ...cases.
In this paper we study a facility location problem in the plane in which a single point (facility) and a rapid transit line (highway) are simultaneously located in order to minimize the total travel time from the clients to the facility, using the L1 or Manhattan metric. The rapid transit line is given by a segment with any length and orientation, and is an alternative transportation line that can be used by the clients to reduce their travel time to the facility. We study the variant of the problem in which clients can enter and exit the highway at any point. We provide an O(n3)-time algorithm that solves this variant, where n is the number of clients. We also present a detailed characterization of the solutions, which depends on the speed given along the highway.
Assessment of water penetration risk in building facades throughout Brazil Domínguez-Hernández, J.; Pérez-Bella, J.M.; Alonso-Martínez, M. ...
Building research and information : the international journal of research, development and demonstration,
07/2017, Letnik:
45, Številka:
5
Journal Article
Recenzirano
The penetration of atmospheric water (rain) into facades creates problems for building habitability and the durability of construction materials. This study analyses the exposure of Brazilian facades ...to the two main climate factors responsible for this penetration: wind-driven rain and driving rain wind pressure. Daily weather records (spanning 2005-14, from 171 weather stations) were analysed. Both exposure factors were combined to assess the risk of water penetration at each site. The relationships between the different exposure indices calculated from daily, monthly and annual records were determined and compared with results from other countries. From this analysis, detailed isopleth maps are provided that allow a graphical characterization of the moisture exposure conditions of facades anywhere in Brazil. A comprehensive characterization of the water penetration exposure in Brazilian enclosures is created and can be used to establish normative design requirements for actual climatic conditions in each area of the country. In general, an increased risk of penetration was identified in the flat areas of the South and Northeast regions of the country. The sites located in the Amazon basin present comparatively lower risks, despite a greater amount of rainfall, because the wind intensity is less in these inland areas.
Abstract
The relative importance or saliency of sensory inputs depend on the animal’s environmental context and the behavioural responses to these same inputs can vary over time. Here we show how ...freely moving rats, trained to discriminate between deviant tones embedded in a regular pattern of repeating stimuli and different variations of the classic oddball paradigm, can detect deviant tones, and this discriminability resembles the properties that are typical of neuronal adaptation described in previous studies. Moreover, the auditory brainstem response (ABR) latency decreases after training, a finding consistent with the notion that animals develop a type of plasticity to auditory stimuli. Our study suggests the existence of a form of long-term memory that may modulate the level of neuronal adaptation according to its behavioural relevance, and sets the ground for future experiments that will help to disentangle the functional mechanisms that govern behavioural habituation and its relation to neuronal adaptation.
Auditory deviance detection is a function of the auditory system that allows reduction of the processing demand for repetitive stimuli while stressing unpredictable ones, which are potentially more ...informative. Deviance detection has been extensively studied in humans using the oddball paradigm, which evokes an event-related potential known as mismatch negativity (MMN). The same stimulation paradigms are used in animal studies that aim to elucidate the neuronal mechanisms underlying deviance detection. In order to understand the circuitry responsible for deviance detection in the auditory cortex (AC), it is necessary to determine the properties of excitatory and inhibitory neurons separately. Measuring the spike widths of neurons recorded extracellularly from the anaesthetized rat AC, we classified them as fast spiking or regular spiking units. These two neuron types are generally considered as putative inhibitory or excitatory, respectively. In response to an oddball paradigm, we found that both types of units showed similar amounts of deviance detection overall. When considering each AC field separately, we found that only in A1 fast spiking neurons showed higher deviance detection levels than regular spiking neurons, while in the rest of the fields there was no such distinction. Interpreting these responses in the context of the predictive coding framework, we found that the responses of both types of units reflect mainly prediction error signaling (i.e., genuine deviance detection) rather than repetition suppression.
•Single units from the auditory cortex were classified as excitatory or inhibitory.•Both inhibitory and excitatory units showed deviance detection.•Inhibitory units showed larger deviance detection than excitatory units in A1 only.•The responses indicated prediction error rather than repetition suppression.•Both types of neurons may contribute to the deviance detection cortical circuits.
Summary
Background Bexarotene is the first synthetic retinoid X receptor‐selective retinoid (rexinoid) approved for the treatment of cutaneous T‐cell lymphoma (CTCL). However, little is known about ...the signalling pathways by which it exerts its anticarcinogenic effect.
Objectives To characterize the effects of bexarotene in CTCL cell lines and elucidate the underlying molecular pathways of its antineoplastic effect.
Methods The cell lines Hut‐78, HH and MJ were used. Cell viability was assessed with the XTT assay. The self‐renewal potential of cells after bexarotene treatment was studied with the methylcellulose clonogenic assay. Flow cytometry was used to analyse the effects on cell cycle, Ki‐67 expression and apoptosis induction. Cell cycle and apoptosis‐related protein expression were determined by Western blot and immunofluorescence.
Results Bexarotene induced a loss of viability and more pronounced inhibition of clonogenic proliferation in HH and Hut‐78 cells, whereas the MJ line exhibited resistance. Bexarotene upregulated and activated Bax in sensitive lines, although not enough to signal significant apoptosis. Instead, all data point to the inhibition of proliferation, rather than apoptosis, as the main mechanistic action of the rexinoid. Bexarotene signals both G1 and G2/M arrest by the modulation of critical checkpoint proteins. We further found that bexarotene activates p53 by phosphorylation at Ser15, which influences the binding of p53 to promoters for cell cycle arrest, induces p73 upregulation, and, in concordance, also modulates some p53/p73 downstream target genes, such as p21, Bax, survivin and cdc2. Bexarotene‐mediated ataxia telangiectasia mutated protein (ATM) activation in all studied lines suggests that ATM is likely to be the p53/p73 upstream activator.
Conclusions Our data indicate for the first time that bexarotene exerts its effect in CTCL mainly by triggering the p53/p73‐dependent cell cycle inhibition pathway, probably by upstream ATM activation. Therefore, bexarotene‐modulated genes represent potential biomarkers to assess the response to treatment of patients with CTCL.
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