Sequências de Fibonacci e a Razão Áurea - aplicações no ensino básico

This thesis aims to present a study of the Fibonacci sequence, initiated from a simple problem of rabbits breeding and the Golden Ratio, which originated from a geometrical construction, for applications in basic education. The main idea of the thesis is to present historical records of the occurrence of these concepts in nature and science and their influence on social, cultural and scientific environments. Also, it will be presented the identification and the characterization of the basic properties of these concepts and howthe connection between them occurs,and mainly, their intriguing consequences. It is also shown some activities emphasizing geometric constructions, links to other mathematics areas, curiosities related to these concepts and the analysis of questions present in vestibular (SAT-Scholastic Aptitude Test) and Enem(national high school Exam) in order to show the importance of these themes in basic education, constituting an excellent opportunity to awaken the students to new points of view in the field of science and life, from the presented subject and to promote new ways of thinking mathematics as a transformative science of society.

Determinación del nitrogeno ureico y urea normales en nuestro medio

Contiene: introducción; concepto de mitrógeno ureico y úrea; importancia en clínica; técnica y casuística; conclusiones y bibliografía

Relación entre la proporción áurea y el parámetro facial de estudiantes de odontología en una universidad de la provincia de Chiclayo, 2014

El objetivo del presente estudio fue relacionar los componentes de la proporción áurea con el parámetro facial de estudiantes de odontología en una universidad de la provincia de Chiclayo, 2014. El diseño del estudio fue transversal, descriptivo y prospectivo. La población de estudio fue representada por 88 estudiantes de una Escuela de Odontología, se diseñó una ficha de recolección según las medidas antropométricas craneofaciales. Se capacitó y se evaluó la estabilidad de la concordancia intra e interexaminador de los investigadores gracias a la participación de un Especialista en Ortodoncia, a fin de lograr una estandarización en las mediciones, verificado mediante una prueba T para muestras pareadas. Se encontró que el 65.91% del total de pacientes presentaban proporción áurea en su dimensión externa, 48.86 % son braquifaciales, 13.64 % mesofaciales, 3.41 % dolicofaciales Se encontró que el 57.95% del total presentaban proporción aurea en su relación vertical, 42.05% son braquifaciales, 10.23 % mesofaciales y 5.68% dolicofaciales. En cuanto al perfil armónico, el 70.45% del total de pacientes no presentan proporción áurea, de los cuales el 53.41% son braquifaciales, 10.23 % son mesofaciales y 6.82% son dolicofaciales. Para el contraste de la hipótesis se utilizó el coeficiente de correlación Chi cuadrado. Para todas las pruebas estadísticas el nivel de significancia fue de <5% (p<0,05) con un 95% de nivel de confiabilidad. Se concluyó que sólo existe relación significativa entre el componente dimensión externa de la proporción áurea y el parámetro facial de los estudiantes de odontología en una universidad de la provincia de Chiclayo.

Pasture production and composition response after killing Eucalypt trees with herbicides in central Queensland

Clearing woodlands is practised world-wide to increase crop and livestock production, but can result in unintended consequences including woody regrowth and land degradation. The pasture response of 2 eucalypt woodlands in the central Queensland rangelands to killing trees with herbicides, in the presence or absence of grazing and regular spring burning, was recorded over 7 or 8 years to determine the long-term sustainability of these common practices. Herbage mass and species composition plus tree dynamics were monitored in 2 replicated experiments at each site. For 8 years following herbicide application, killing Eucalyptus populnea F. Muell. (poplar box) trees resulted in a doubling of native pasture herbage mass from that of the pre-existing woodland, with a tree basal area of 8.7 m2 ha-1. Conversely, over 7 years with a similar range of seasons, killing E. melanophloia F. Muell. (silver-leaved ironbark) trees of a similar tree basal area had little impact on herbage mass grown or on pasture composition for the first 4 years before production then increased. Few consistent changes in pasture composition were recorded after killing the trees, although there was an increase in the desirable grasses Dichanthium sericeum (R. Br.) A. Camus (Queensland bluegrass) and Themeda triandra Forssk. (kangaroo grass) when grazed conservatively. Excluding grazing allowed more palatable species of the major grasses to enhance their prominence, but seasonal conditions still had a major influence on their production in particular years. Pasture crown basal area was significantly higher where trees had been killed, especially in the poplar box woodland. Removing tree competition did not have a major effect on pasture composition that was independent of other management impositions or seasons, and it did not result in a rapid increase in herbage mass in both eucalypt communities. The slow pasture response to tree removal at one site indicates that regional models and economic projections relating to tree clearing require community-specific inputs.

Herbicides cross resistance of a multiple resistant short-awn foxtail ( Alopecurus aequalis Sobol.) population in wheat field

Alopecurus aequalis Sobol. is a common grass weed, which has become increasingly troublesome to control in China wheat fields. One A. aequalis population, collected from Anhui Province China, was suspected to be resistant to fenoxaprop-P-ethyl and mesosulfuron-methyl. This study aimed to establish the cross-resistance pattern using the purified subpopulation and explore the potential targetsite and non-target-site based resistance mechanisms. Sequencing results showed that a single nucleotide change of ATT to AAT was present in acetyl-CoA carboxylase (ACCase) gene of the resistant (R) plants, resulting in an Ile2041Asn amino acid substitution. Besides, another single nucleotide change of CCC to CGC was present in acetolactate synthase (ALS) gene of the R plants, resulting in a Pro197Arg amino acid substitution. The homozygous resistant plants were isolated and the seeds were used in whole-plant herbicide bioassays. Compared with the susceptible (S) population, R population displayed high level resistance to fenoxaprop-P-ethyl and mesosulfuronmethyl. Cross resistance patterns showed that the R population was highly resistant to clodinafop-propargyl, moderately resistant to pyroxsulam and flucarbazoncsodium, lowly resistant to pinoxaden, and susceptible to tralkoxydim, sethoxydim, and isoproturon. The pretreatment of piperonyl butoxide reduced the 50% growth reduction (GR50) value of fenoxaprop-P-ethyl, suggesting that target-site resistance and non-target-site resistance mechanisms were both present in fenoxaprop- P-ethyl-resistance of A. aequalis. This is the first report of ACCase Ile2041Asn and ALS Pro197Arg mutation in A. aequalis.

Poly(epsilon-caprolactone)nanocapsules as carrier systems for herbicides: Physico-chemical characterization and genotoxicity evaluation

The toxicity of herbicides used in agriculture is influenced by their chemical stability, solubility, bioavailability, photodecomposition, and soil sorption. Possible solutions designed to minimize toxicity include the development of carrier systems able to modify the properties of the compounds and allow their controlled release. Polymeric poly(epsilon-caprolactone) (PCL) nanocapsules containing three triazine herbicides (ametryn, atrazine, and simazine) were prepared and characterized in order to assess their suitability as controlled release systems that could reduce environmental impacts. The association efficiencies of the herbicides in the nanocapsules were better than 84%. Assessment of stability (considering particle diameter, zeta potential, polydispersity, and pH) was conducted over a period of 270 days, and the particles were found to be stable in solution. In vitro release kinetics experiments revealed controlled release of the herbicides from the nanocapsules, governed mainly by relaxation of the polymer chains. Microscopy analyses showed that the nanocapsules were spherical, dense, and without aggregates. In the infrared spectra of the PCL nanocapsules containing herbicides, there were no bands related to the herbicides, indicating that interactions between the compounds had occurred. Genotoxicity tests showed that formulations of nanocapsules containing the herbicides were less toxic than the free herbicides. The results indicate that the use of PCL nanocapsules is a promising technique that could improve the behavior of herbicides in environmental systems. (C) 2012 Elsevier B.V. All rights reserved.

Synthesis of waterborne polyurethane-urea dispersions with chain extension step in homogeneous and heterogeneous media

Hypothesis: The possibility of tailoring the final properties of environmentally friendly waterborne polyurethane and polyurethane-urea dispersions and the films they produce makes them attractive for a wide range of applications. Both the reagents content and the synthesis route contribute to the observed final properties. Experiments: A series of polyurethane-urea and polyurethane aqueous dispersions were synthesized using 1,2-ethanediamine and/or 1,4-butanediol as chain extenders. The diamine content was varied from 0 to 4.5 wt%. Its addition was carried out either by the classical heterogeneous reaction medium (after phase inversion step), or else by the alternative homogeneous medium (prior to dispersion formation). Dispersions as well as films prepared from dispersions have been later extensively characterized. Findings: 1,2-Ethanediamine addition in heterogeneous medium leads to dispersions with high particle sizes and broad distributions whereas in homogeneous medium, lower particle sizes and narrow distributions were observed, thus leading to higher uniformity and cohesiveness among particles during film formation. Thereby, stress transfer is favored adding the diamine in a homogeneous medium; and thus the obtained films presented quite higher stress and modulus values. Furthermore, the higher uniformity of films tends to hinder water molecules transport through the film, resulting, in general, in a lower water absorption capacity.

Utilization of nitrogen (15N) from urea and green manures by rice as affected by nitrogen fertilizer rate.

The use of green manures (GMs) in combination with nitrogen (N) fertilizer application is a promising practice to improve N fertilizer management in agricultural production systems. The main objective of this study was to evaluate the N use efficiency (NUE) of rice plant, derived from GMs including sunn hemp (Crotalaria juncea L.), millet (Pennisetum glaucum L.) and urea in the greenhouse. The experimental treatments included two GMs (sunn hemp-15N and millet-15N), absence of N organic source (without GM residues in soil) and four N rates, as urea-15N (0, 28.6, 57.2 and 85.8 mg N kg-1). The results showed that both rice grain and straw biomass yields under sunn hemp were greater than that of millet or without the application of GM. The NUE of rice under sunn hemp was greater than that under millet (18.9 and 7.8% under sunn hemp and millet, respectively). The urea N application rates did not affect the fertilizer NUE by rice (53.7%) with or without GMs. The NUE of GMs by rice plants ranged from 14.1% and 16.8% for root and shoot, respectively. The study showed that green manures can play an important role in enhancing soil fertility and N supply to subsequent crops.

Selectivity and efficiency of herbicides in weed control on sweet sorghum.

A carência de herbicidas registrados para o controle de plantas daninhas, em sorgo sacarino, torna-se fator limitante à produção. Objetivou-se avaliar a seletividade de herbicidas em sorgo sacarino e a eficiência no controle de plantas daninhas. O delineamento experimental foi de blocos ao acaso, com quarto repetições. Os tratamentos incluíram cultivares de sorgo sacarino (BRS 506, BRS 509 e BRS 511) e herbicidas aplicados isoladamente em pré-emergência (atrazine - 1.500 g ha-1; atrazine + s-metolachlor - 1.665 g ha-1 + 1.035 g ha-1; flumioxazin - 50 g ha-1; s-metolachlor - 1.440 g ha-1) e pós-emergência (tembotrione - 100,8 g ha-1) e de forma sequencial em pré e pós-emergência (atrazine + s-metolachlor + tembotrione - 1.665 g ha-1 + 1.035 g ha-1 + 100,8 g ha-1; atrazine + tembotrione - 1.500 g ha-1 + 100,8 g ha-1; flumioxazin + tembotrione - 50 g ha-1 + 100,8 g ha-1), mais duas testemunhas, uma capinada e outra sem capina. A fitotoxicidade ao sorgo foi de 98,0 %, 98,0 % e 100 % de tembotrione; 100 %, 98,7 % e 100 % de flumioxazin + tembotrione; 100 %, 100 % e 100 % de atrazine + s-metolachlor + tembotrione; e 98,7 %, 98,7 % e 99,7 % de atrazine + tembotrione, respectivamente para as cultivares BRS 509, BRS 506 e BRS 511. Tembotrione, flumioxazin + tembotrione, atrazine + s-metolachlor + tembotrione e atrazine + tembotrione apresentaram bom controle de Ipomoea indivisa, Digitaria ciliaris e Urochloa plantaginea, porém, não demonstraram seletividade às cultivares de sorgo. O atrazine, de modo geral, apresentou maior seletividade aos componentes de rendimento das cultivares BRS 509 e BRS 506.

Porta-enxertos clonais para pessegueiro: estabelecimento da unidade de observação com a cultivar jade na colônia Santa Áurea, em Pelotas-RS.

2015

Effect of post-emergent herbicides application on carotenoid concentration in green corn.

Considering the influence of herbicides in the metabolism of the carotenoids in corn, the objective of the present study was to evaluate the effect of herbicides and genotype on carotenoids concentration. The green corn hybrids BRS 1030 and P30F53 were subjected to a post-emergent herbicides application at 20 and 30 days after emergence. Carotenoids were extracted from corn grains and analyzed to quantify ?- and ?-carotene, lutein, zeaxanthin, ?-cryptoxanthin, total carotenoids (TC), and total of vitamin A carotenoids precursors (proVA). The application of foramsulfuron + iodosulfuron-methyl-sodium (40 + 2.6 g ha-1), nicosulfuron (20 g ha-1), mesotrione (120 g ha-1) and tembotrione (80 g ha-1 and 100 g ha-1) promoted higher concentration of carotenoids in fresh green corn. Lutein, zeaxanthin, ?-cryptoxanthin, ?-carotene, ?-carotene, proVA carotenoids, and TC concentration increased after foramsulfuron + iodosulfuron-methyl-sodium in late application (V5 to V6), nicosulfuron in both applications, mesotrione applied post-initial (V3 to V4), tembotrione (100 g ha-1) in both applications and tembotrione (80 g ha-1) in late post-application, at least for one hybrid. The content of carotenoids in the green corn kernels differed between ?BRS 1030? and ?P30F53?. Our results suggest a possibility of significant increase of carotenoids in green corn kernels through the handling of corn production with post-emergent herbicides.

Fertilizers with coated urea in upland rice production and nitrogen apparent recovery.

Urea is the most used N fertilizer for upland rice, however, a great percentage of N loss can occur with the use of this fertilizer. The use of products that provide reduction of N loss for urea fertilizers can contribute to increase N use efficiency. The objective of this study was to determine the effect of N rates applied in the form of coated urea in the content and accumulation of N in dry biomass, apparent recovery of nitrogen and grain yield of upland rice. The experimental design was a randomized complete blocks arranged in a 4 x 3 + 1 factorial scheme. The treatments consisted of four sources of N fertilizer [1. Common urea; 2. Polymer-coated urea for slow release of N (PCU); 3. urea with the urease inhibitor N-(n-Butyl) thiophosphoric triamide (NBPT); and 4. urea coated with copper sulfate and boric acid as urease inhibitors (UCCB)], with three fertilization rates (30, 60 and 90 kg ha-1 of N). In addition, we included a control treatment without N application. Coated urea did not provide increases in rice grain yield in relation to common urea. The increasing amount of N resulted in significant increases in rice grain yield (from 3217 to 5548 kg ha-1, 2010/11, and from 3392 to 4560 kg ha-1, 2011/12). The apparent nitrogen recovery rate decreased with the increase in N applied doses.