Metabolic rate limits the effect of sperm competition on mammalian spermatogenesis.

Sperm competition leads to increased sperm production in many taxa. This response may result from increases in testes size, changes in testicular architecture or changes in the kinetics of spermatogenesis, but the impact of each one of these processes on sperm production has not been studied in an integrated manner. Furthermore, such response may be limited in species with low mass-specific metabolic rate (MSMR), i.e., large-bodied species, because they cannot process energy and resources efficiently enough both at the organismic and cellular levels. Here we compare 99 mammalian species and show that higher levels of sperm competition correlated with a) higher proportions of seminiferous tubules, b) shorter seminiferous epithelium cycle lengths (SECL) which reduce the time required to produce sperm, and c) higher efficiencies of Sertoli cells (involved in sperm maturation). These responses to sperm competition, in turn, result in higher daily sperm production, more sperm stored in the epididymides, and more sperm in the ejaculate. However, the two processes that require processing resources at faster rates (SECL and efficiency of Sertoli cells) only respond to sperm competition in species with high MSMR. Thus, increases in sperm production with intense sperm competition occur via a complex network of mechanisms, but some are constrained by MSMR

Plant Biostimulants from urban waste and crop by-product and their nutrients use efficiency

Plant biostimulants can be microbial or non-microbial, and their function is to improve crops nutrients use efficiency. The aim was to evaluate the nutrients use efficiency of two non-microbial biostimulants from urban waste and olive by-product. The experiment was conducted in a hydroponic chamber in a vegetable (lettuce, Lactuca sativa) and in an aromatic plant (thyme, Thymus vulgaris L.). Three treatments were tested: C= commercial nutrient solution (NS); G1= NS + 5% biostimulant from olive by-product (pomace); B1= NS + 5% biostimulant from urban waste. In both G1 and B1 treatments, biostimulants were produced in aerated conditions. Each crop cycle lasted 22 days. During the experiment, temperature, humidity and luminosity of the chamber were monitored, as well as pH, CE, temperature and SN consumption. At the end of the experiment, root length (RL), leaf and root dry weight (DWL; DWR), leaf and root fresh weight (FWL; FWR) and number of leaves (NL) were measured. As main results, biostimulants presence resulted in an inhibitory effect on lettuce, particularly in NL and FWL. In contrast, biostimulants used in thyme, mainly G1, showed highest values of NL (~65% higher than C), FWL and DWL, and no significant differences between B1 in DWR. In conclusion, biostimulants from urban waste and olive by-product are promising for advancing sustainable agricultural practices and contributing to circular economy. However, a deeper understanding of their mechanism of action is essential for development and market.N/

Selective Sorbent Enrichment of Nickel Ions from Aqueous Solutions using a Hierarchically Hybrid Organic-Inorganic Polymer Based on Double Imprinting Concept

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)This study involves the preparation of an ion imprinted organic-inorganic polymer (IIP) for selective sorbent enrichment of Ni(2+) from aqueous solutions with further determination by GF AAS. The hybrid polymeric network was prepared from a mixture of 2-aminoethyl-3-aminobutylmethyldimethoxysilane as functional monomer, and tetraethoxysilane as crosslinking agent, containing Ni(2+) and cetyltrimethylammonium bromide as templates. The polymers were characterized by IR, TG and SEM. The maximum adsorptive capacity of IIP towards Ni(2+) ions, determined by linear Langmuir model, was found to be 5.44 mg g(-1). When the selectivity coefficient of IIP was compared with the selectivity coefficient of NIP (non imprinted polymer) and IIP2 (ion imprinted polymer in the absence of surfactant), from the binary mixtures of Ni(2+)/Cu(2+), Ni(2+)/Co(2+), Ni(2+)/Cd(2+) and Ni(2+)/Zn(2+), values of relative selectivity coefficient (k') were 36.54 and 3.55, 1.22 and 2.03, 4.43 and 1.42, 28.60 and 1.74, respectively, demonstrating higher selectivity of IIP for Ni(2+) ions. The proposed method provided a limit of detection of 0.16 mu g L(-1) and was successfully applied for Ni(2+) determination in spiked water samples and in a phytoterapic product (Gingko Biloba) with satisfactory recovery values.213419430Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)INCT of Bioanalytical (Instituto Nacional de Ciencia e Tecnologia de Bioanalitica)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

EMPLOY OF SILICA GEL ORGANICALLY MODIFIED AND IONICALLY IMPRINTED FOR SELECTIVE ON-LINE PRECONCENTRATION OF COPPER IONS

EMPLOY OF SILICA GEL ORGANICALLY MODIFIED AND IONICALLY IMPRINTED FOR SELECTIVE ON-LINE PRECONCENTRATION OF COPPER IONS. The present work purposes the preparation of a silica gel sorbent organically modified with 2-aminoethyl-3-aminobutylmethyldimethoxysilane (AAMDMS) and imprinted with Cu(2+) ions by means surface imprinting technique and its use for selective on-line sorbent preconcentration of Cull ions with further UV-VIS spectrophotometric determination by flow injection analysis. The Cu(2+)-imprinted silica gel, when compared with non imprinted silica gel and silica gel, showed from the binary mixture Of Cu(2+)/Ni(2+) relative selectivity coefficient (k') of 6.84 and 5.43 and 6.64 and 19.83 for the mixture Cu(2+)/Pb(2+), thus demonstrating higher selectivity of Cu(2+)-imprinted silica gel towards Cull ions. Under optimized condition, the on-fine preconcentration method provided detection limit of 3.4 mu g L(-1) and linear range ranging from 30.0 up to 300.0 mu g L(-1) (r = 0.995). The accuracy of method was successfully assessed by analyzing different kind of spiked water samples with recovery values ranging from 92.2 up to 103.0%.33230130

Effect of different bulking agents and turning on composting of olive pomace

Portugal é o quarto maior produtor de azeite da União Europeia, gerando grande quantidade de bagaço de azeitona (BA), subproduto fitotóxico. A compostagem é uma alternativa para seu tratamento e este trabalho avaliou dois agentes estruturantes (AE): biomassa florestal (BF) e casca de amêndoa (CA), em 7 pilhas, sendo: pilha BA+ (100%BA; C/N 19); pilha BABF+ (50%BA, 50%BF; C/N 26); pilha BACA+ (50%BA, 50%CA; C/N 33); pilha BABFCA+ (50%BA, 25%BF, 25%CA; C/N 33); pilha BACA- (50%BA, 50%CA; C/N 33); pilha BABF- (50%BA, 50%BF; C/N 26); pilha BA- (100%BA; C/N 19), onde (+) indica pilhas revolvidas e (-) estáticas. Monitorizou-se temperatura (T), humidade, densidade, pH, condutividade elétrica, cinzas e fitotoxicidade. As concentrações de C orgânico total (COT), azoto total (Nt), C/O, H/C e C/N foram obtidas por análise química elementar. Como principais resultados, as pilhas (-) apresentaram valores mais baixos de T e cinzas e maior COT e Nt, indicando a decomposição mais lenta do material. BA+ e BA- apresentaram os maiores teores de Nt e tardaram mais na perda da fitotoxicidade. Conclui-se que houve efeito positivo dos AE e revolvimento na decomposição do material, perda de fitotoxicidade e consequentemente, na estabilização e mineralização da matéria orgânica.Portugal is the fourth largest producer of olive oil in the European Union, resulting in a large generation of olive pomace (BA), a phytotoxic by-product. Composting is an alternative for its treatment and this study evaluated two bulking agents (AE): forest biomass (BF) and almond husk (CA), in 7 piles: pile BA+ (100%BA; C/N 19); BABF+ (50%BA, 50%BF; C/N 26); BACA+ (50%BA, 50%CA; C/N 33); BABFCA+ (50%BA, 25%BF, 25%CA; C/N 33); BACA- (50%BA, 50%CA; C/N 33); BABF- (50%BA, 50%BF; C/N 26); BA- (100%BA; C/N 19), the sign (+) indicates turned piles and (-) static piles. Temperature (T), humidity, density, pH, EC, ash and phytotoxicity were monitored. Concentrations of total organic carbon (COT), total nitrogen (Nt), C/O, H/C and C/N ratios were determined through elemental chemical analyses. As the main results, piles (-) showed lower T and ash content and higher COT and Nt, indicating slower decomposition. BA+ and BA- showed the highest Nt values and the piles lost their phytotoxicity. It was concluded that there was a positive effect of AE and turning, improving the decomposition of the material, losing phytotoxicity and consequently, enhancing the stabilization and mineralization of organic matterOs autores agradecem à empresa Acushla, à equipa do More, ao Instituto Politécnico de Bragança e ao Projeto BIOMA (POCI-01-0247-FEDER-046112) pelo suporte.info:eu-repo/semantics/publishedVersio

Highly improved sensitivity of TS-FF-AAS for Cd(II) determination at ng L-1 levels using a simple flow injection minicolumn preconcentration system with multiwall carbon nanotubes

A new method for cadmium determination at ng L-1 levels is described. The method is based on the on-line coupling of a flow preconcentration system using multiwall carbon nanotubes (MWCNT) as sorbent with TS-FF-AAS determination. Cadmium preconcentration was at pH 4.9 onto an MWCNT minicolumn (30 mg) for 2 min at a 5.0 mL min(-1) flow rate. The elution step is performed by using 0.5 mol L-1 HNO3 and the cadmium desorbed is directly pumped to a TS-FF-AAS. All experimental parameters that play important roles in system performance were evaluated and optimized by means of fractional factorial designs and response surface methodology. The excellent characteristics of MWCNT as sorbent, mainly owing to its high surface area, make it possible to obtain a preconcentration factor of 51-fold, thus improving the detection and quanti. cation limits in TS-FF-AAS, 11.4 and 38.1 ng L-1, respectively. When the flow preconcentration system, FI-TS-FF-AAS, was compared with FAAS alone, an increase in the sensitivity of 640-fold was obtained. The calibration graph was linear with a correlation coefficent higher than 0.999 from 38.1 to 1250 ng L-1. Repeatability of the measurements (n = 10), assessed as relative standard deviation (RSD), was found to be 6.5 and 2.1% for cadmium concentrations of 100 and 1000 ng L-1, respectively. Important parameters to characterize the flow preconcentration system were also evaluated, the consumption index being 0.196 mL, the concentration efficiency 25.5 min(-1) and the sample throughput 20 samples per hour. In order to demonstrate the accuracy of the system, addition and recovery studies in water samples (mineral water, tap water and river water) and cigarette samples were carried out. Moreover, for the same purpose, cadmium was determined in certified biological materials (Bovine Liver and Rye Grass), giving an average result in close agreement with the certified value.21111305131

PRODUTIVIDADE DA SOJA EM SEMEADURA DIRETA COM ANTECIPAÇÃO DA ADUBAÇÃO NA CULTURA DE Eleusine coracana

The possibility of early soybean fertilization carried out on the predecessor crop has several benefits, mainly operational ones, making the production system more conservationist and balanced. An experiment was carried out at the Anhumas Experimental Station, Luiz de Queiroz College of Agriculture (USP/ESALQ), located in Piracicaba, SP, Brazil, during 2001/2002, 2002/2003, and 2003/2004 agricultural years on a typic Hapludox aiming to evaluate the effects of the early fertilization on soybean yield. The fertilization consisted of applying 90 kg ha−1 of P2O5, 50 kg ha−1 of K2O, and micronutrients (Co, Cu, Fe, Mn, Mo, and Zn). The experiment was conducted in a randomized complete block design with three replications and 12 treatments consisting of different levels of early soybean fertilization carried out on the finger millet crop: T1, no fertilization; T2, conventional soybean fertilization; T3, early 50% K fertilization; T4, early 100% K fertilization; T5, early 50% P fertilization; T6, early 50% P and K fertilization; T7, early 50% P and 100% K fertilization; T8, early 100% P fertilization; T9, early 100% P and 50% K fertilization; T10, early 100% P and K fertilization; T11, early 100% P and K fertilization + micronutrients; and T12, early leaf fertilization with micronutrients. The results showed that the early soybean sowing fertilization with phosphorus and potassium carried out during finger millet sowing does not interfere with the thousand-seed weight and soybean yield.A possibilidade da antecipação da adubação da soja em uma cultura antecessora traz inúmeros benefícios, principalmente, operacionais e colabora para que o sistema de produção seja mais conservacionista e equilibrado. Com o objetivo de avaliar os efeitos da adubação antecipada sobre a produtividade da cultura da soja foi conduzido o presente experimento na Estação Experimental Anhumas, Escola Superior de Agricultura “Luiz de Queiroz” (USP/ESALQ), em Piracicaba-SP, nos anos agrícolas 2001/2002, 2002/2003 e 2003/2004, em Latossolo Amarelo distrófico. A adubação consistiu da aplicação de 90 kg ha-1de P2O5, 50 kg ha-1 de K2O e de micronutrientes (Co, Cu, Fe, Mn, Mo e Zn). O experimento adotou delineamento em blocos completos casualizados com três repetições e 12 tratamentos que consistiram em diferentes níveis de antecipação da adubação da soja para a cultura do capim-pé-de-galinha: T1= nenhuma adubação; T2= adubação convencional na soja; T3= antecipação de 50% de K; T4= antecipação de 100% de K; T5= antecipação de 50% de P; T6= antecipação de 50% de P e K; T7= antecipação de 50% de P e 100 % de K; T8= antecipação de 100% de P; T9= antecipação de 100% de P e 50% de K; T10= antecipação de 100% de P e K; T11= antecipação de 100% de P e K + micronutrientes; T12= antecipação da adubação foliar com micronutrientes. Conclui-se que a antecipação da adubação de semeadura com fósforo e potássio da cultura da soja para a semeadura do capim-pé-de-galinha não interfere com a massa de mil sementes e nem com a produtividade agrícola da soja