Size dependent symmetry breaking in models for morphogenesis

A general property of dynamical systems is the appearance of spatial and temporal patterns due to a change of stability of a homogeneous steady state. Such spontaneous symmetry breaking is observed very frequently in all kinds of real systems, including the development of shape in living organisms. Many nonlinear dynamical systems present a wide variety of patterns with different shapes and symmetries. This fact restricts the applicability of these models to morphogenesis, since one often finds a surprisingly small variation in the shapes of living organisms. For instance, all individuals in the Phylum Echinodermata share a persistent radial fivefold symmetry. In this paper, we investigate in detail the symmetry-breaking properties of a Turing reaction–diffusion system confined in a small disk in two dimensions. It is shown that the symmetry of the resulting pattern depends only on the size of the disk, regardless of the boundary conditions and of the differences in the parameters that differentiate the interior of the domain from the outer space. This study suggests that additional regulatory mechanisms to control the size of the system are of crucial importance in morphogenesis

On the optimal demand-side management in microgrids through polygonal composition

This article presents a novel methodology for energy management in microgrids focused on the demand side. It is inspired by the Tangram puzzle. The energy demand and production profiles are represented by polygons and managed through computational geometry. Therefore, an optimization problem is defined to place n energy demand profiles (pieces) to cover the total energy production profile (target shape). The optimization problem is addressed with a genetic algorithm. It tries to calculate the optimal positions of the polygons of the demands covering the maximum energy production. Since the referred production comes from renewable energy sources in the microgrid, this method allows reducing both the consumption of fossil fuels and energy bills

Venom allergen-like proteins in secretions of plant-parasitic nematodes activate and suppress extracellular plant immune receptors

Parasitic worms threaten human, animal and plant health by infecting people, livestock and crops worldwide. Animals and plants share an anciently evolved innate immune system. Parasites modulate this immune system by secreting proteins to maintain their parasitic lifestyle. This thesis describes how venom-allergen-like proteins (VAPs) that both animal- and plant-parasitic nematodes release into their hosts, modulate host innate immunity. On the one hand we found that one particular secreted VAP from the potato cyst nematode can activate host defenses in tomato plants, opening an opportunity for plant breeders to generate novel nematode-resistant cultivars. We showed that plants make more efficiently use of their limited repertoire of immune receptors by guarding common virulence targets of multiple unrelated plant pathogens. While on the other hand, we describe how VAPs may be used by parasites to suppress the host defense responses mediated by extracellular immune receptors. In short, this fundamental study contributes to our understanding of the molecular basis of persistent infections by parasitic nematodes in plants and in animals.</p

Multi-objective heuristics applied to robot task planning for inspection plants

Robotics are generally subject to stringent operational conditions that impose a high degree of criticality on the allocation of resources and the schedule of operations in mission planning. In this regard the so-called cost of a mission must be considered as an additional criterion when designing optimal task schedules within the mission at hand. Such a cost can be conceived as the impact of the mission on the robotic resources themselves, which range from the consumption of battery to other negative effects such as mechanic erosion. This manuscript focuses on this issue by presenting experimental results obtained over realistic scenarios of two heuristic solvers (MOHS and NSGA-II) aimed at efficiently scheduling tasks in robotic swarms that collaborate together to accomplish a mission. The heuristic techniques resort to a Random-Keys encoding strategy to represent the allocation of robots to tasks whereas the relative execution order of such tasks within the schedule of certain robots is computed based on the Traveling Salesman Problem (TSP). Experimental results in three different deployment scenarios reveal the goodness of the proposed technique based on the Multi-objective Harmony Search algorithm (MOHS) in terms of Hypervolume (HV) and Coverage Rate (CR) performance indicators

Evaluation of polyherbal methionine and choline in feedlot rations for lambs

Requirements of lambs for choline and methionine have not been clearly established, but because of their metabolic relationship, the availability of these two nutrients may affect protein synthesis and energy balance. Therefore, a trial was carried out to evaluate the effect on productive performance and blood metabolites of including methionine and choline from polyherbal mixtures in finishing lamb diets. Forty Hampshire x Suffolk lambs weighing 26.9 ± 2.8 kg were used for a 45-day experiment. The treatments were arranged as a 2x2 factorial, in which the factors were dietary supplementation with herbal methionine and choline at two levels (0% and 0.4% of dry matter (DM)). The treatments had no effects on the lambs’ productive variables (daily feed intake, average daily gain, and feed to gain ratio), carcass characteristics and lipid metabolites (P &gt;0.05). The results indicated that the inclusion of polyherbal mixtures containing methionine, choline and their combination at 0.4% of DM in finishing lamb diets showed no benefits in productive response or in blood metabolites related to lipid metabolism. Keywords: amino acid, lipid metabolites, productive performance, ruminally protected, vitami

Reusing intravaginal progesterone releasing devices for oestrous synchoronization in ewes

In this study, the second use of an intravaginal progesterone-releasing device or controlled intravaginal drug release device (CIDR) was evaluated. After a first use of 11 days, the CIDR was again used for either nine or 12 days with 200 or 300 IU equine chorionic gonadotrophin (eCG) being injected on its removal. Sixty-four ewes were randomly distributed to four treatments (n=16/group): CIDR9+eCG200, CIDR9+eCG300, CIDR12+eCG200, and CIDR12+eCG300. The eCG was administered intramuscularly on withdrawal of the device. Thus, the experiment was a completely randomized design with a 2×2 factorial arrangement of treatments. Oestrus presentation did not differ between treatments (P =0.29). However, with the dose of 200 IU of eCG, oestrus presentation tended to increase (P =0.08). The onset and duration of oestrus, percentage of gestation, and return to oestrus did not differ between treatments (P &gt;0.05). Progesterone concentration in serum was greater (P &lt; 0.05) in ewes treated with CIDR12+eCG300. Prolificacy was greatest (1.44) with the CIDR12+eCG300 treatment and was different (P = 0.001) from the treatments CIDR9+eCG200 (1.21) and CIDR9+eCG300 (1.20), but not from the CIDR12+eCG200 treated ewes (1.31). The CIDR12+eCG300 treatement produced the highest percentage of twin births (45.8%) (P =0.001). Leaving the device in place for 12 days increased (P =0.001) the incidence of twin births. Use of the CIDR for a second time synchronized oestrus in ewes successfully with better fertility being obtained when the device was left in place for 12 days, and 300 IU of eCG was injected on its removal. Key words: gonadotropin, progesterone device, synchronizatio

Utilization of glycerin byproduct derived from soybean oil biodiesel as a carbon source for heterologous protein production in Pichia pastoris

AbstractCrude glycerol, also known as glycerin, is the main byproduct of the biodiesel industry. It has been estimated that up to 40,000tons of glycerin will be produced each year by 2020. This study evaluated the value-added use of crude glycerol derived from soybean biodiesel preparation as a carbon source for heterologous protein production using the yeast Pichia pastoris. Eleven glycerin samples were obtained by methanolysis of soybean oil using different acids or bases as catalysts. Cell growth experiments showed that crude glycerol containing either potassium or sodium hydroxide resulted in 1.5–2 times higher final cell densities when compared to glycerol P.A. Finally, crude glycerol containing sodium hydroxide was successfully utilized for constitutive heterologous α-amylase production in P. pastoris. This study demonstrated that crude glycerol without any purification steps may be directly used as carbon source for protein production in P. pastoris

RIAM-VASP module relays integrin complement receptors in outside-in signaling driving particle engulfment

The phagocytic integrins and complement receptors M 2/CR3 and X 2/CR4 are classically associated with the phagocytosis of iC3b-opsonized particles. The activation of this receptor is dependent on signals derived from other receptors (inside-out signaling) with the crucial involvement of the Rap1-RIAM-Talin-1 pathway. Here, we analyze the implication of RIAM and its binding partner VASP in the signaling events occurring downstream of 2 integrins (outside-in) during complement-mediated phagocytosis. To this end, we used HL-60 promyelocytic cell lines deficient in RIAM or VASP or overexpressing EGFP-tagged VASP to determine VASP dynamics at phagocytic cups. Our results indicate that RIAM-deficient HL-60 cells presented impaired particle internalization and altered integrin downstream signaling during complement-dependent phagocytosis. Similarly, VASP deficiency completely blocked phagocytosis, while VASP overexpression increased the random movement of phagocytic particles at the cell surface, with reduced internalization. Moreover, the recruitment of VASP to particle contact sites, amount of pSer157-VASP and formation of actin-rich phagocytic cups were dependent on RIAM expression. Our results suggested that RIAM worked as a relay for integrin complement receptors in outside-in signaling, coordinating integrin activation and cytoskeletal rearrangements via its interaction with VASPThis work has been supported by Ministerio Español de Economía y Competitividad (MINECO) grants: SAF2016-77096-R (ELD and CC), BIO2014:54164-R (PAR), BIO2017-86500-R (MY-M), EI/MICIU EXPLORA BIO2017-91272-EXP & FEDER (PI17/02303) (S.R.-P). AT-G is supported by a predoctoral fellowship from MINECO, JLS-T is supported by a predoctoral fellowship from Universidad Complutense de Madrid, RT-R is supported by a postdoctoral fellowship from Asociación Española Contra el Cáncer (AECC