Does the use of nest materials in a ground-nesting bird result from a compromise between the risk of egg overheating and camouflage?

Many studies addressing the use of nest materials by animals have focused on only one factor to explain its function. However, the consideration of more than one factor could explain the apparently maladaptive choice of nest materials that make nests conspicuous to predators. We experimentally tested whether there is a trade-off in the use of nest materials between the risks of egg predation versus protection from overheating. We studied the ground-nesting Kentish plover, Charadrius alexandrinus, in southern Spain. We added materials differing in thermal properties and coloration to the nests, thus affecting rates of egg heating, nest temperature and camouflage. Before these manipulations, adults selected materials that were lighter than the microhabitat, probably to buffer the risk of egg overheating. However, the adults did not keep the lightest experimental materials, probably because they reduced camouflage, and this could make the nests even more easily detectable to predators. In all nests, adults removed most of the experimental materials independently of their properties, so that egg camouflage returned to the original situation within a week of the experimental treatments. Although the thermal environment may affect the choice of nest materials by plovers, ambient temperatureswere not so high at our study site as to determine the acceptance of the lightest experimental materials

A class of Steffensen type methods with optimal order of convergente

In this paper, a family of Steffensen type methods of fourth-order convergence for solving nonlinear smooth equations is suggested. In the proposed methods, a linear combination of divided differences is used to get a better approximation to the derivative of the given function. Each derivative-free member of the family requires only three evaluations of the given function per iteration. Therefore, this class of methods has efficiency index equal to 1.587. Kung and Traub conjectured that the order of convergence of any multipoint method without memory cannot exceed the bound 2d-1, where d is the number of functional evaluations per step. The new class of methods agrees with this conjecture for the case d=3. Numerical examples are made to show the performance of the presented methods, on smooth and nonsmooth equations, and to compare with other ones. © 2011 Elsevier Inc. All rights reserved.This research was supported by Ministerio de Ciencia y Tecnologia MTM2010-18539.Cordero Barbero, A.; Torregrosa Sánchez, JR. (2011). A class of Steffensen type methods with optimal order of convergente. Applied Mathematics and Computation. 217(19):7653-7659. https://doi.org/10.1016/j.amc.2011.02.067S765376592171

Pengaruh Latihan Barbell Pullover terhadap Kekuatan Otot Lengan dan Bahu pada Tim Voli Putra SMP Negeri 6 Pekanbaru

, the purpose of this research is want to know is there the effect of Barbell Pullover exercise toward strenght of arm and shoulder musclus of smpn 6 pekanbaru man vollyball club, so when do under servise, the ball can pass over the net. Type of this research is experimental, the population in this research was the students of smpn 6 pekanbaru man vollyball club who actively doing exercise, the total was 10 students. Sampling technique used as sample ( sugiyono 2008 : 124 ). Total sample of this research is 10 students of smpn 6 pekanbaru man vollyball club. Data tecnique used was surfaited sampling, it is determination of the sample when all members are the population are used as sample. The instruments was used in this research was expanding dynamometer, which is aimed to measure the strength og arm and shoulder muscles. After that, the data was analysis by using statistic to examine the normality with liliefors test on the significant level 0,05a. The subritted hypothesis was there is the effect of Barbell Pullover exercise toward strength of arm and shoulder muscles. Based on the data analysis t test showed T count was 21,95 and T table was 1,812, it means that T count > T table. Based on the statistic data analysis, the average of preetest was 12,1 and the average of posttest 15,7 was it. Shows that the data was normal. In conclution , there was the effect of Barbell Pullover exercise toward strength of arm and shoulder of smpn 6 pekanbaru man vollyball club

Prototype Lemari Pengering Pakaian Otomatis

Pemanasan Global yang menyebabkan Perubahan cuaca yang tidak menentu. Perubahan cuaca yang tidak menetukan ini yang menyebabkan kerepotan jika hujan turun menerus, sehingga pakaian yang sudah di cuci tidak bisa kering. Karena hal inilah yang memunculkan ide untuk menciptakan alat pengering pakaian otomatis. Mikrokontroler ATMega328 digunakan sebagai pengontrol dalam proses pengeringan secara elektronik. Hal ini lebih mudah untuk mengeringkan pakaian tanpa harus menunggu cuaca cerah. Sensor suhu dan kelembaban DHT-11 digunakan sebagai pendeteksi suhu didalam ruangan pengeringan pakaian. Lampu bholam yang digunakan sebagai komponen pengering dan kipas fan digunakan untuk menyebarkan panas dalam ruangan pengeringan pakaian. Sedangkan Arduino Uno sebagai software untuk mengontrol Mikrokontroler ATMega328. Hasil penelitian menunjukkan bahwa alat mampu mengeringkan 1pakaian dengan jumlah waktu 17 menit dan panas matahari memerlukan waktu 1 jam 5 menit. Jadi jarak waktu pengeringan otomatis dengan panas matahari sekitar 1 jam. Dengan demikian alat pengering pakaian ini dapat di gunakan sebagai pengganti sinar matahari jika cuaca hujan

Stability analysis of Jacobian-free Newton's iterative method

[EN] It is well known that scalar iterative methods with derivatives are highly more stable than their derivative-free partners, understanding the term stability as a measure of the wideness of the set of converging initial estimations. In multivariate case, multidimensional dynamical analysis allows us to afford this task and it is made on different Jacobian-free variants of Newton¿s method, whose estimations of the Jacobian matrix have increasing order. The respective basins of attraction and the number of fixed and critical points give us valuable information in this sense.This research was partially supported by Spanish Ministerio de Ciencia, Innovacion y Universidades PGC2018-095896-B-C22 and Generalitat Valenciana PROMETEO/2016/089.Amiri, A.; Cordero Barbero, A.; Darvishi, M.; Torregrosa Sánchez, JR. (2019). Stability analysis of Jacobian-free Newton's iterative method. Algorithms. 12(11):1-16. https://doi.org/10.3390/a12110236S1161211Grau-Sánchez, M., Noguera, M., & Amat, S. (2013). On the approximation of derivatives using divided difference operators preserving the local convergence order of iterative methods. Journal of Computational and Applied Mathematics, 237(1), 363-372. doi:10.1016/j.cam.2012.06.005Amiri, A. R., Cordero, A., Darvishi, M. T., & Torregrosa, J. R. (2018). Preserving the order of convergence: Low-complexity Jacobian-free iterative schemes for solving nonlinear systems. Journal of Computational and Applied Mathematics, 337, 87-97. doi:10.1016/j.cam.2018.01.004Amiri, A. R., Cordero, A., Darvishi, M. T., & Torregrosa, J. R. (2018). Stability analysis of Jacobian-free iterative methods for solving nonlinear systems by using families of mth power divided differences. Journal of Mathematical Chemistry, 57(5), 1344-1373. doi:10.1007/s10910-018-0971-9Neta, B., Chun, C., & Scott, M. (2014). Basins of attraction for optimal eighth order methods to find simple roots of nonlinear equations. Applied Mathematics and Computation, 227, 567-592. doi:10.1016/j.amc.2013.11.017Geum, Y. H., Kim, Y. I., & Neta, B. (2015). A class of two-point sixth-order multiple-zero finders of modified double-Newton type and their dynamics. Applied Mathematics and Computation, 270, 387-400. doi:10.1016/j.amc.2015.08.039Cordero, A., Soleymani, F., & Torregrosa, J. R. (2014). Dynamical analysis of iterative methods for nonlinear systems or how to deal with the dimension? Applied Mathematics and Computation, 244, 398-412. doi:10.1016/j.amc.2014.07.010Cordero, A., Maimó, J. G., Torregrosa, J. R., & Vassileva, M. P. (2017). Multidimensional stability analysis of a family of biparametric iterative methods: CMMSE2016. Journal of Mathematical Chemistry, 55(7), 1461-1480. doi:10.1007/s10910-016-0724-6Chicharro, F. I., Cordero, A., & Torregrosa, J. R. (2013). Drawing Dynamical and Parameters Planes of Iterative Families and Methods. The Scientific World Journal, 2013, 1-11. doi:10.1155/2013/78015

Real qualitative behavior of a fourth-order family of iterative methods by using the convergence plane

The real dynamics of a family of fourth-order iterative methods is studied when it is applied on quadratic polynomials. A Scaling Theorem is obtained and the conjugacy classes are analyzed. The convergence plane is used to obtain the same kind of information as from the parameter space, and even more, in complex dynamics. (C) 2014 IMACS. Published by Elsevier B.V. All rights reserved.This research was supported by Ministerio de Ciencia y Tecnologia MTM2011-28636-C02-{01,02}.Magreñán Ruiz, ÁA.; Cordero Barbero, A.; Gutiérrez Jiménez, JM.; Torregrosa Sánchez, JR. (2014). Real qualitative behavior of a fourth-order family of iterative methods by using the convergence plane. Mathematics and Computers in Simulation. 105:49-61. https://doi.org/10.1016/j.matcom.2014.04.006S496110

Two-directional synthesis and biological evaluation of alkaloid 5-epi-cis-275B′

The first total synthesis of myrmicine ant alkaloid 5-epi-cis-275B0 (4) is presented. A tandem cyclisation stablished the entire core of the structure in a single transformation as well as the required 2,5-anti stereochemistry. Two-directional synthesis was used to furnish the cyclisation precursor 2, as in each of the subsequent steps towards the natural product. The first electrophysiology studies for 4 (against nicotinic acetylcholine receptors) were also conducted, finding modest inhibition of current

Combining tissue engineering with metal scaffolds in orthopaedic to improve osseointegration of endoprothesis

Electron Beam Melting (EBM) technology allows the fabrication of free-formed metal scaffolds, thus creating the possibility of manufacturing patient-specific endo-prostheses. It also allows the production of highly-porous prostheses with an elastic modulus similar to that of bone. The porous can be filled-in with tissue engineering elements (i.e. osteogenic molecules, biomaterials, cells) in order to promote bone ingrowth inside them, thus improving the prostheses osseointegration. For this purpose, the surface of EBM-sintered titanium should permit cell adhesion, growth and differentiation to ensure a good metal-to-tissue interaction. Our goal was to evaluate the osteoconductivity of EBM-manufactured Ti6Al4V porous scaffolds. Porous Ti6Al4V discs were manufactured by EBM-sintering, autoclave-sterilized and seeded with human and rat osteoblasts and mesenchymal stem cells (MSC). Cell adhesion, proliferation and differentiation were assessed by vital staining, MTT assay, RT-PCR and immunostaining techniques. Bone organ-explant culture was used to further assess osteoconductivity at tissue level in vitro. Both osteoblastic and MSC attached to and grew on the titanium discs, covering up the entire metal surface, and even bridging the pores of the scaffold. Collagen type I, osteopontin, and osteocalcin expression confirmed the osseous differentiation of the cells cultured on the titanium discs. Bone explants placed on EBM-sintered titanium alloy spontaneously released cells that covered up the metal surface. Long-term cultured explants strongly adhered to the titanium. EBM-sintered titanium scaffolds promote cell adhesion and can be populated by osteoblastic and MSC, which can normally differentiate towards the osteogenic lineage upon proper stimulation. These osteoconductive properties should promote the osseointegration of EBM-manufactured endoprostheses for bone replacement.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech