Long-Term Effect of Crop Succession Systems on Soil Chemical and Physical Attributes and Soybean Yield.

Most soybean producers in the Cerrado biome use the direct seeding system, making it essential to cultivate cash or cover crops in the off-season, to promote soil protection, as well as increase organic matter, which is directly related to improvements in the chemical and physical characteristics of these soils. In this sense, this work was conducted in Jataí, state of Goias, Brazil, to evaluate the physical-chemical attributes of the soil and the performance of soybeans cultivated in different crop succession systems cultivated for 6 years in the region of Jataí, GO. The experimental design was randomized blocks with four plots and four replications; the crops that followed soybeans were arranged as follows: T1-corn (Zea mays); T2-pearl millet (Pennisetum glaucum); T3-Urochloa ruziziensis; and T4-corn + Urochloa ruziziensis. Soybean yield components and grain yield were evaluated in two harvests (2020/2021 and 2021/2022). Deformed and undisturbed soil samples were collected in 2022 to assess soil fertility and for physical analysis. The data were subjected to analysis of variance (F test) and the means were compared using the Tukey test at 5% probability. The soybean-millet succession system stood out for the chemical and physical attributes of the soil: calcium, magnesium, base saturation, hydrogen + aluminum, and total porosity. The crop succession system did not affect yield for the two years analyzed, but the accumulated grain yields were higher in the crop succession soybean/corn intercropped. The results highlight the importance of using cover crops in improving the physical and chemical qualities of the soil in the long term. However, in the Cerrado, there is a predominance of the soybean/corn succession system motivated by financial issues to the detriment of the qualitative aspects of the soil, in which the introduction of Urochloa ruziziensis in intercropping with corn would improve the chemical attributes of the soil and have a long-term impact on the accumulated grain production.

Causal inference and GWAS: Rubin, Pearl, and Mendelian randomization.

Although Genome Wide Analysis (GWAS) have been widely used to understand the genetic architecture of complex quantitative traits, interpreting their results in terms of the biological processes that determine those traits has been difficult or even lacking, because of the variability in responses to the tests of hypotheses within a trait, species, and breed or cross, and the lack of follow-up studies. It is then essential employing appropriate statistical tests that point out to the causal genes responsible of the relevant fraction of the genetic variability observed. We briefly review the main theoretical aspects of the two schools of causal inference (Rubin's Causal Model, RCM, and Pearl's causal inference, PCI). RCM approachs the hypothesis testing from a randomization perspective by considering a wider space of the observation, i.e. the "potential outcomes", rather than the narrower space that results from defining "treatment" effects after observing the data. Next, we discuss the assumptions involved to meet the requirements of randomization for RCM with observational data (non-designed experiments) with special emphasis on the Stable Unit Treatment Analysis (SUTVA). Due to the presence of "confounders" (i.e. systematic fixed effects, environmental permanent effects, interaction among genes, etc.), causal average treatment effects are viewed through the familiar lens of normal linear (or mixed) models. To overcome the difficulties of association analyses, a tests of causal effects is introduced using independent predicted residual breeding values from animal models of genetic evaluation that avoids the effects of population structure and confounder effects. An independent section discusses the issue of whether the additive effects defined at the "gene" level by R. A. Fisher and popularized in D. S. Falconer's textbook of quantitative genetics can be termed causal from either RCM or PCI.

Antioxidant Activity and Oxidative Damage Associated with Seeding Surgery for Pearl Culture in the Winged Pearl Oyster Pteria sterna.

To evaluate the antioxidant activity and oxidative damage by relaxing, wounding, and seeding of a saibo of different origin on Pteria sterna hosts, five oyster treatments were included: (1) relaxed (REL) but neither wounded nor seeded; (2) relaxed and wounded (WOU) but not seeded; (3) relaxed, wounded, and seeded with an allograft (ALL); (4) relaxed, wounded, and seeded with an autograft (AUT); and (5) unrelaxed, unwounded, and unseeded as control (CTR). Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and thiobarbituric acid (TBARS) activity were quantified between 3 and 24 h post-seeding. Compared to the CTR oysters, which did not suffer oxidative stress, SOD activity significantly decreased in the gonad and digestive gland in all treatments and decreased in mantle tissue in AUT oysters; this indicates that the entire process of preparing oysters for pearl culture (relaxing, wounding, and seeding) generates oxidative stress in the host. CAT was not a sensitive enzyme for measuring the short-term response of oysters to the wounding-seeding processes but rather a more prolonged or chronic stress. Similar to SOD, the lowest GPx and TBARS activity in seeded oysters evidenced their susceptibility to oxidative stress and damage, particularly in the WOU treatment. Evidence from this study indicates that SOD is a more sensitive enzyme for measuring the short-term response of the host oyster to the wounding and seeding of a saibo. It is also clear that the host undergoes stress at all stages of the pearl culture process, mostly during gonad wounding and regardless of the origin of saibo.

Is pearl millet (Pennisetum glaucum) a good plant species for ecotoxicological tests?

Various plant species can be selected for environmental testing, including pearl millet (Pennisetum glaucum (L.) R. Br), a globally significant cereal crop. This study aims to assess millet's suitability as a species for ecotoxicological tests, examining (1) germination and initial development dynamics, (2) the minimum seed quantity for reliable sampling, (3) optimal experimental design with replication numbers, (4) suitability of positive control, and (5) the effectiveness of the protocol in evaluating toxic effects of environmental pollutants. Millet exhibited rapid and uniform germination as well as consistent initial seedling development. To establish the minimum number of seeds required for reliable experimentation, germination, and seedling growth were compared across plots containing 10, 25, and 50 seeds. Consequently, 10 seeds per plot were chosen for subsequent experiments to reduce labor and costs while maintaining reliability. To validate the selected experimental design, and to establish a positive control for assays, aluminum was used as a toxic element at concentrations ranging from 10-2 to 10-6 M. While aluminum did not affect the final percentage of germinated seeds, it did exhibit an impact on the Germination Speed Index (GSI). Significant differences in root and aerial growth, and with fresh weight, were observed. The 10-3M concentration was chosen as the positive control as the 10-2 concentration showed extreme toxicity. To assess the applicability of the established protocol in determining the toxic effects of environmental pollutants, millet roots were exposed to the toxic agents atrazine, cadmium, methyl methane sulfonate (MMS), and Spent pot liner (SPL). Millet demonstrated sensitivity and efficiency in response to these tests. In conclusion, millet proves to be an effective species for the toxicological risk assessment of environmental pollutants.

"Tabela Periódica" da Anticoncepção ­ uma ferramenta na escolha contraceptiva / "Periodic Table" of Contraception ­ a tool in the contraceptive choice

Estima-se que 40% das gestações no mundo sejam não planejadas. Em países de baixa renda, complicações no parto são a maior causa de morte entre mulheres de 15 a 19 anos. A disponibilidade de métodos contraceptivos reversíveis é necessária para o adequado planejamento reprodutivo. Entre os métodos reversíveis, os de longa ação (LARCs) são os mais efetivos. Métodos de curta ação (SARCs) são preferenciais para pacientes que desejam gestar a curto prazo e para as quais a gestação não será indesejada. O presente estudo é uma revisão narrativa da literatura, de artigos em inglês e português publicados entre 2009 e 2020, utilizando as bases de dados SciELO, Medline e Embase. O objetivo desta revisão é apresentar os LARCs e SARCs em uma tabela com dados comparativos que auxiliem na tomada de decisão do médico e da paciente e permita estabelecer estratégias para um planejamento familiar adequado.(AU)

It is estimated that 40% of pregnancies in the world are unplanned. In low-income countries, complications in childbirth are the major cause of death among women aged 15 to 19 years. The availability of reversible contraceptive methods is necessary for proper reproductive planning. Among the reversible methods, long-acting reversible contraception (LARCs) is the most effective. Short-acting reversible contraception (SARCs) methods are preferred for patients who wish to become pregnant in the short term and for whom pregnancy will not be undesirable. The present study is a narrative review of the literature, of articles in English and Portuguese published between 2009 and 2020, using the databases SciELO, Medline and Embase. The purpose of this review is to present the LARCs and SARCs in a table with comparative data that assist in the decision making of the doctor and the patient and allow to establish strategies for adequate family planning.(AU)

Feed intake, methane yield, and efficiency of utilization of energy and nitrogen by sheep fed tropical grasses.

Forage allowance impacts dry matter (DM) intake and the use of nutrients by ruminants. The efficient use of protein and energy from pasture is related to better livestock performance and lower environmental impacts. The aims of this study were to evaluate the effect of forage allowance levels on intake, digestibility, nitrogen (N) and energy balance, and methane (CH4) emissions by lambs fed fresh pearl millet [Pennisetum americanum (L.) Leeke]. An indoor trial was performed using lambs in a completely randomized design with four treatments [forage allowance at 1.5, 2.0, 2.5 kg DM/100 kg of live weight (LW), and ad libitum allowing 20% of refusals] and four replicates (lambs). Forage intake, digestibility, total urine and feces excretion, and CH4 emission were measured to calculate N and energy balances. An increase in forage allowance resulted in a linear increase in lamb forage intake, N retention, and metabolizable energy intake. Moreover, lamb CH4 emission (g/day) also increased with greater forage allowance, while CH4 yield decreased linearly as forage allowance increased. Our results indicate that maximizing forage intake improves N and energy use efficiency and mitigates CH4 yield and decreases CH4 conversion factor (Ym) by lambs fed pearl millet forage. Thus, management strategies that optimize intake of tropical forages by ruminants improve the use of nutrients ingested and mitigates negative impacts to the environment.

Efficiency of the primary health care policy in Brazilian municipalities: an application of the Pearl's Structural Causal Model / A eficiência da política de atenção básica de saúde nos municípios brasileiros: uma aplicação do Modelo Causal Estrutural de Pearl

ABSTRACT Background In recent years, public health policies and their effects on improving health outcomes have been gaining prominence in the economic literature and on the agenda of international organizations. Objective This study aims to evaluate the causal effect of the "Pacto pela Saúde" (Pact for Health) program on health policy performance in terms of a Health Vulnerability Index (HVI) of Brazilian municipalities from 2006 to 2013. The "Pacto pela Saúde" program is the current operational standard of the Brazilian Unified Health System (SUS). One of the main guidelines of this program was to improve health policy governance. Method The effect resulting from efficiency gains of the participation of municipalities in the health policy on the HVI was estimated by the Pearl's Structural Causal Model. Results The results indicate a positive and significant impact of efficiency management on the reduction of health vulnerability in the municipalities. The Pearl's Causal Model and the back-door criterion of causal identification were employed to calculate the effects of the "Pacto pela Saúde" program on the HVI. Conclusion The use of Pearl's method in this study contributed to a more comprehensive analysis of the effects of the "Pacto pela Saúde" program on health outcomes and, therefore, its use in future research on the analysis of public policies is recommended.

RESUMO Introdução A condução da política de saúde pública e seus efeitos sobre a melhoria dos resultados de saúde vêm ganhando destaque nos últimos anos na literatura econômica e na agenda dos organismos internacionais. Objetivo Avaliar o efeito causal do Pacto pela Saúde sobre o desempenho da política de saúde, em termos de um indicador de vulnerabilidade de saúde (IVS), dos municípios brasileiros no período de 2006 a 2013. O Pacto pela Saúde é a norma operacional vigente pelo Sistema Único de Saúde (SUS) do Brasil e teve como uma de suas principais diretrizes o aprimoramento da governança da política de saúde. Método A estimação do efeito causal decorrente dos ganhos de eficiência da participação do município na política sobre o IVS se deu por meio do Modelo Causal Estrutural (MCE) de Pearl. Resultados Houve a estimação de um impacto positivo e significante da eficiência da gestão sobre a queda da vulnerabilidade de saúde dos municípios e a adequação do MCE e do critério back-door de Pearl de identificação causal com o cálculo do efeito do Pacto pela Saúde sobre o IVS. Conclusão A utilização do método de Pearl contribuiu para uma análise mais adequada do efeito do Pacto pela Saúde sobre os IVS, e, portanto, recomenda-se sua utilização em estudos futuros de análise de políticas públicas.

Phosphorus availability and dynamics in soil affected by long-term ruzigrass cover crop.

The use of grasses as cover crops in the off-season of cash crops under no-till has been largely adopted. However, soil phosphorus (P) uptake was previously shown to be reduced when ruzigrass is introduced in the rotation, affecting the viability and sustainability of this cropping system. The objective of this study was to assess the effect of ruzigrass on soil P availability and desorption kinetics under different P fertilizer application rates. A long-term field experiment where soybean (Glycine max) has been grown in rotation with ruzigrass (Urochloa ruziziensis) or fallow for 10 years, with the application of 0, 13, and 26 kg ha-1 of P, was evaluated for two consecutive years. Soil P desorption kinetics was assessed using diffusive equilibrium (DET) and gradient in thin films (DGT) techniques, as well as the DGT-induced fluxes in soils model (DIFS). Microbial biomass P (MBP) was assessed to verify if soil solution P (PDET) was reduced due to immobilization by microorganisms. Ruzigrass reduced MBP and PDET especially when P fertilizer was applied. The concentration of labile P (PDGT) was also lower after ruzigrass than in fallow. The soil ability to resupply P to soil solution was lower after ruzigrass regardless of P rates due to a slower desorption in response to the perturbation imposed by DGT. Growing ruzigrass as cover crop in the soybean off-season decreases soil P availability regardless of P fertilizer application rates by fundamentally reducing P mobility and P resupply from soil solid phase into soil solution.

Stabilization of spherical nanoparticles of iron(III) hydroxides in aqueous solution by wormlike micelles.

HYPOTHESIS: The low Ksp value of Fe(OH)3 (3 × 10-38 at 298 K) explain the immediate coagulation when the pH of a solution of Fe(III) is adjusted to 7. However, stable dispersions of Fe(OH)3 can be formed when the pH is adjusted to 7 in the presence of wormlike micelles formed by cetyltrimethylammonium bromide and sodium salicylate. The formation of a structure containing Fe(OH)3 nanoparticles decorating wormlike micelles is responsible for the high stability of the dispersions. EXPERIMENTS: Fe(OH)3 nanoparticles were obtained by increasing the pH of solutions of cetyltrimethylammonium bromide and Fe(III), previously complexed with salicylate at pH 3. The interaction between nanoparticles and the chains of wormlike micelles was investigated by DLS, SAXS, TEM and Cryo-TEM. FINDINGS: DLS revealed higher scattering contrast and slower diffusion for wormlike micelles in the presence of nanoparticles. These results were interpreted as the decoration of the chains of wormlike micelles by nanoparticles of Fe(OH)3. A pearl-necklace model was successfully used to adjust SAXS curves, revealing nanoparticles with ∼3 nm of diameter, spaced ∼2 nm apart along the string. This result agrees with TEM and Cryo-TEM images. The formed structure prevents the coagulation of nanoparticles, assuring high stability to the dispersion.

Pcr-rflp for identification of the pearl oyster Pinctada imbricate from Brazil and Venezuela / Pcr-rflp para identificação de ostras perlíferas (Pinctada imbricate) do Brasil e Venezuela

Oysters of the genus Pinctada are of great economic importance due to their extensive use in human feeding and pearl cultivation. It includes four species: Pinctada radiata (Europe), P. imbricata (Western Atlantic)and the P. fucata-martensi complex (Pacific), the latter being a species complex of difficult morphological differentiation. Although this species complex has several molecular studies corroborating each species as valid, there are still doubts about the validity of P. imbricata in the South of Western Atlantic (ie Brazilian Coast). Here we carried out a RFLP study with populations from Ceará, Rio de Janeiro, São Paulo and Venezuela coast. We analyzed mitochondrial (16S) and nuclear genes (partial IGS). This study confirms the Brazilian and Venezuelan stocks as genetically close to the P. imbricata stocks from Caribbean than the P. martensi-fucata complex. This result is important for pearl-oyster farmers, demonstrating that the Brazilian and Venezuelan stocks are not alien species or hybrids of Indo-Pacific species.(AU)

As ostras do género Pinctada são de grande importância económica devido ao seu uso extensivo na alimentação humana e cultivo de pérolas. Inclui quatro espécies: Pinctada radiata (Europa), P. imbricata (Atlântico Ocidental) e P. fucatamartensi (Pacífico), sendo esta última uma espécie complexa de difícil diferenciação morfológica. Embora este complexo de espécies tenha vários estudos moleculares corroborando cada espécie como válida, ainda há dúvidas sobre a validade de P. imbricata no Sul do Atlântico Ocidental. Neste trabalho realializou-se um estudo de RFLP com populações do Ceará, Rio de Janeiro, São Paulo e costa da Venezuela. Foram analisados genes mitocondriais (16S) e nucleares (IGS parcial). Este estudo confirma que os espécimes brasileiros e venezuelanos são geneticamente mais próximos às populações de P. imbricata do Caribe do que o complexo P. martensi-fucata. Esse resultado é importante para os produtores de ostras perlíferas, demonstrando que os estoques brasileiro e venezuelano não são espécies exóticas ou híbridas de espécies indo-pacíficas.(AU)

Pcr-rflp for identification of the pearl oyster Pinctada imbricate from Brazil and Venezuela / Pcr-rflp para identificação de ostras perlíferas (Pinctada imbricate) do Brasil e Venezuela

Oysters of the genus Pinctada are of great economic importance due to their extensive use in human feeding and pearl cultivation. It includes four species: Pinctada radiata (Europe), P. imbricata (Western Atlantic)and the P. fucata-martensi complex (Pacific), the latter being a species complex of difficult morphological differentiation. Although this species complex has several molecular studies corroborating each species as valid, there are still doubts about the validity of P. imbricata in the South of Western Atlantic (ie Brazilian Coast). Here we carried out a RFLP study with populations from Ceará, Rio de Janeiro, São Paulo and Venezuela coast. We analyzed mitochondrial (16S) and nuclear genes (partial IGS). This study confirms the Brazilian and Venezuelan stocks as genetically close to the P. imbricata stocks from Caribbean than the P. martensi-fucata complex. This result is important for pearl-oyster farmers, demonstrating that the Brazilian and Venezuelan stocks are not alien species or hybrids of Indo-Pacific species.

As ostras do género Pinctada são de grande importância económica devido ao seu uso extensivo na alimentação humana e cultivo de pérolas. Inclui quatro espécies: Pinctada radiata (Europa), P. imbricata (Atlântico Ocidental) e P. fucatamartensi (Pacífico), sendo esta última uma espécie complexa de difícil diferenciação morfológica. Embora este complexo de espécies tenha vários estudos moleculares corroborando cada espécie como válida, ainda há dúvidas sobre a validade de P. imbricata no Sul do Atlântico Ocidental. Neste trabalho realializou-se um estudo de RFLP com populações do Ceará, Rio de Janeiro, São Paulo e costa da Venezuela. Foram analisados genes mitocondriais (16S) e nucleares (IGS parcial). Este estudo confirma que os espécimes brasileiros e venezuelanos são geneticamente mais próximos às populações de P. imbricata do Caribe do que o complexo P. martensi-fucata. Esse resultado é importante para os produtores de ostras perlíferas, demonstrando que os estoques brasileiro e venezuelano não são espécies exóticas ou híbridas de espécies indo-pacíficas.

Occurrence of 15 Haplotypes of Linepithema micans (Hymenoptera: Formicidae) in Southern Brazil.

The ant genus Linepithema is widely known, thanks to the pest species Linepithema humile (Mayr), which is easily mistaken for Linepithema micans (Forel) due to their morphological similarity. Like L. humile, L. micans is associated to the main grapevine pest in Brazil, Eurhizococcus brasiliensis (Wille), also known as ground pearl. Therefore, the present study uses mtDNA fragments to expand the knowledge of haplotype diversity and distribution of L. micans in the state of Rio Grande do Sul (Brazil), to understand the genetic differences of the populations identified in this study. We identified 15 haplotypes of L. micans spread across different localities. Twelve of these haplotypes were new for the species. The high haplotype diversity uncovered in Rio Grande do Sul (Brazil) for this species was predictable, as L. micans is in its native environment. Additional studies that take gene flow into account may reveal interesting aspects of diversity in these populations.

Cálculo del Índice de Pearl de etinilestradiol 30 mcg/drospirenona 3 mg (Genesa®)

Objetivo: Calcular el índice de Pearl de Genesa® en mujeres venezolanas. Métodos: Estudio fase IV, prospectivo y abierto. Las pacientes recibieron etinilestradiol 30 mcg / drospirenona 3 mg (Genesa®): un comprimido diario desde el primer día de la menstruación por 21 días; descanso de siete días y reinicio el día ocho. Resultados: Se ingresaron al estudio 115 pacientes, se obtuvo un índice de Pearl de 0,98. Los efectos adversos fueron: un embarazo, incremento de peso, retención de líquidos, náuseas, manchas en la piel. Conclusiones: Etinilestradiol 30 mcg/drospirenona 3 mg (Genesa®) presenta un adecuado índice de Pearl en mujeres venezolanas.

Objective: To calculate the Pearl index of Genesa® in Venezuelan women. Methods: Phase IV prospective and open study. Patients received ethinylestradiol 30 mcg / drospirenone 3 mg (Genesa®): one tablet daily from the first day of menstruation for 21 days; seven-day break and restart the eighth day. Results: 115 patients were admitted to the study, a Pearl index of 0.98 was obtained. Most common side effects: one pregnancy, weight gain, fluid retention, nausea, skin blemishes. One patient discontinued treatment for adverse effects (vomiting and nausea). Conclusions: Genesa® presents an adequate Pearl Index in Venezuelan woman.

Development of SSR marker by RNA-seq and its application in genotyping pearl sac in pearl oyster Pinctada fucata martensii

Background: Pearl oyster Pinctada fucata martensii is cultured for producing round nucleated pearls. Pearl production involves a surgical operation where a mantle tissue graft from a donor oyster and a round nucleus are implanted in the gonad of a host oyster. Whether the mantle graft implanted in the gonad of a host oyster contributes to the formation of a pearl sac that secretes pearl nacre to form a pearl should be determined. In April 2012, two full-sib families were separately used as donor and host oysters for a nucleus insertion operation. The pearl sac was sampled from the host oysters at day 60 after nucleus operation. A large number of simple sequence repeat (SSR) markers were developed using Illumina HiSeq™ 2000 platform. The two full-sib families were also used to mine diagnostic SSR markers for genotyping donor oyster, host oyster, and pearl sac. Results: A total of 3168 microsatellite loci were identified in 39,078 unigenes, and 1977 SSR primers were designed by Primer 3.0. Forty-seven SSR primers were validated, and the rate of successful amplification was 72.3%. Two diagnostic SSR primers could successfully genotype pearl sac, donor oyster, and host oyster. Donor and host oysters were both homogenous, and the alleles in pearl sac were identical to those in donor and host oysters. Conclusions: The present results confirmed that the mantle graft implanted in the gonad of host oyster contributed to the formation of the pearl sac in pearl oyster P. fucata martensii.

Comparative study of different carbon-supported Fe2O3-Pt catalysts for oxygen reduction reaction.

One of the challenges in electrocatalysis is the adequate dispersion of the catalyst on an appropriate porous support matrix, being up to now the most commonly used the carbon-based supports. To overcome this challenge, carbon supports must first be functionalized to guide the catalyst's nucleation, thereby, improving the dispersion and allowing the use of smaller amount of the catalyst material to achieve a higher electrochemically active surface area. This study present the effect of functionalized Vulcan carbon XC72 (FVC) and functionalized Black Pearl carbon (FBPC) as supports on the catalytic activity of decorated Fe2O3 with Pt. Both carbons were functionalized with HNO3 and subsequently treated with ethanolamine. Fe2O3 nanoparticles were synthesized by chemical reduction and decorated with platinum by epitaxial growth. Pt and Fe2O3 structural phases were identified by XRD and XPS; the Pt content was measured by XPS, and results showed to a high Pt content in Fe2O3-Pt/FBPC. TEM micrographs reveal nanoparticles with an average size of 2 nm in both supported catalysts. The Fe2O3-Pt/FVC catalyst presents the highest specific activity and mass activity, 0.21 mA cm-2Pt and 140 mA mgPt-1, respectively, associated to the appropriate distribution of platinum on the Fe2O3 nanoparticles.

Overcoming Phosphorus Deficiency in West African Pearl Millet and Sorghum Production Systems: Promising Options for Crop Improvement.

West Africa (WA) is among the most food insecure regions. Rapid human population growth and stagnating crop yields greatly contribute to this fact. Poor soil fertility, especially low plant available phosphorus (P) is constraining food production in the region. P-fertilizer use in WA is among the lowest in the world due to inaccessibility and high prices, often unaffordable to resource-poor subsistence farmers. This article provides an overview of soil P-deficiency in WA and opportunities to overcome it by exploiting sorghum and pearl millet genetic diversity. The topic is examined from the perspectives of plant breeding, soil science, plant physiology, plant nutrition, and agronomy, thereby referring to recent results obtained in a joint interdisciplinary research project, and reported literature. Specific objectives are to summarize: (1) The global problem of P scarcity and how it will affect WA farmers; (2) Soil P dynamics in WA soils; (3) Plant responses to P deficiency; (4) Opportunities to breed for improved crop adaptation to P-limited conditions; (5) Challenges and trade-offs for improving sorghum and pearl millet adaptation to low-P conditions in WA; and (6) Systems approaches to address soil P-deficiency in WA. Sorghum and pearl millet in WA exhibit highly significant genetic variation for P-uptake efficiency, P-utilization efficiency, and grain yield under P-limited conditions indicating the possibility of breeding P-efficient varieties. Direct selection under P-limited conditions was more efficient than indirect selection under high-P conditions. Combining P-uptake and P-utilization efficiency is recommendable for WA to avoid further soil mining. Genomic regions responsible for P-uptake, P-utilization efficiency, and grain yield under low-P have been identified in WA sorghum and pearl millet, and marker-assisted selection could be possible once these genomic regions are validated. Developing P-efficient genotypes may not, however, be a sustainable solution in itself in the long-term without replenishing the P removed from the system in harvested produce. We therefore propose the use of integrated soil fertility management and systems-oriented management such as enhanced crop-tree-livestock integration in combination with P-use-efficiency-improved varieties. Recycling P from animal bones, human excreta and urine are also possible approaches toward a partially closed and efficient P cycle in WA.

Use of eugenol as an anaesthetic for Geophagus brasiliensis juveniles / Utilização de eugenol como anestésico em juvenis de Geophagus brasiliensis

The eugenol is the active ingredient of clove oil and it has shown to be effective and safe as fish anesthetic. In this study were evaluated the effects of different concentrations of eugenol for anesthesia, recovery time, blood glucose and hematocrit percentage of pearl cichlid (Geophagus brasiliensis) juveniles. Concentrations of 50, 80, 100, 120, 150, 170 and 200 mg L-1 eugenol were evaluated in terms of time to achieve the different stages of anesthesia and recovery in a completely randomized design (CRD) with 12 repetitions. These results were tested using the Kruskal-Wallis test with subsequent Dunn test. The evaluated concentrations had anesthetic action of the deep induction 172.57 ± 25 s (50 mg L-1) and the period of full recovery of 516.25 ± 102 s (200 mg L-1), with statistical difference between the treatments at all the stages. The eugenol effect on blood glucose and on hematocrit percentage at 0 h after deep anesthesia was evaluated for concentrations of 0; 50; 80; 100; 150; 200 mg L-1, in a completely randomized design with five replications, and the results were assessed by One-Way ANOVA. Glucose and percentage of hematocrit: no statistically significant differences (P>0.05) were observed for these variables.All concentrations of eugenol showed to be effective as an anesthetic for G. brasiliensis and did not affect the survival, blood glucose and the percentage of hematocrit. To minimize adverse effects and achieve faster recovery is indicate the use of 50-80 mg L-1 of eugenol for pearl cichlid juveniles.(AU)

O eugenol, substância ativa do óleo de cravo, tem demonstrado ser eficiente e seguro como anestésico para peixes. Neste estudo foram avaliados os efeitos de diferentes concentrações de eugenol na anestesia, tempo de recuperação, glicemia e percentual de hematócrito de cará (Geophagus brasiliensis). Concentrações de 50, 80, 100, 120, 150, 170 e 200 mg L-1 de eugenol foram avaliadas em relação aos tempos para atingir os diferentes estágios de anestesia e de recuperação, em desenho inteiramente casualizado (DIC), com 12 repetições. Os resultados foram analisados pelos testes de Kruskal-Wallis e teste Dunn. As concentrações avaliadas produziram ação anestésica em período de indução profunda de 172,57 ± 25 s (50 mg L-1) e no período de total recuperação de 516,25 ± 102 s (200 mg L-1), com diferença estatística entre os tratamentos para todas as fases avaliadas. Foi avaliado o efeito do eugenol sobre a glicose no sangue e sobre o percentual de hematócrito, em 0 h após anestesia profunda, nas concentrações 0, 50, 80, 100, 150 e 200 mg L-1, em DIC com cinco repetições, e os resultados avaliados através de ANOVA uma via. Não foram observadas diferenças estatísticas significativas (P>0,05) para glicose e hematócrito. Todas asconcentrações de eugenol avaliadas apresentaram eficiência como anestésico para G. brasiliensis enão afetaram a sobrevivência, a glicose sanguínea e o percentual de hematócrito. Para minimizarefeitos adversos não avaliados e obter recuperação mais rápida, indica-se o uso de 50 a 80 mg L-1 deeugenol para juvenis de carás.(AU)

Anatomical differences among specimens of Pinctada imbricata Rõding, 1798 from different South American localities / Diferenças anatômicas entre espécimes de Pinctada imbricata Rõding, 1798 de diferentes localidades da América do Sul

In the present study, we compared the internal and external anatomy of pearl oyster (Pinctada imbricata Rõding, 1798) from some South American localities, including Venezuela and several regions of Brazil. The anatomical data shows non-geographical variations characterized by variable outline in adults, different degrees of posterior auricle shell development and mantle papillae ranging from normal to digitiform. The geographical variations can be divided into two major groups: the Venezuelan group presents a more folded mantle; pallial muscle grouped in anterior and median-posterior sets; poorly-developed perpendicular mantle groove; inner lamella not extended into the anterior mantle. Brazilian group specimens present a smoother mantle, with less clear separation between anterior and posterior mantle muscle groups; externally-developed perpendicular groove; inner lamella extension developed in anterior mantle. These differences may represent ecophenotypes or differences among isolated South American populations, which may be elucidated by subsequent phylogeographic studies.(AU)

No presente estudo comparou-se a anatomia da ostra perlífera (Pinctada imbricata Rõding, 1798) de algumas localidades da América do Sul, incluindo a Venezuela e várias regiões do Brasil. Foram encontradas variações não geográficas e geográficas. As variações não geográficas foram caracterizadas por adultos com contorno bem variável, diferentes graus de desenvolvimento da aurícula posterior e papilas da lamela interna do manto variando de normal a digitiformes. Variações geográficas podem ser divididas em dois grandes grupos: o grupo venezuelano apresentou um manto mais pregueado; musculatura palial agrupada em dois conjuntos de feixes um anterior e outro mediano-posterior; sulco perpendicular do manto pouco desenvolvido. Espécimes dos grupos brasileiros apresentaram um manto menos pregueado, com separação menos nítida entre os feixes musculares paliais anterior e posterior do manto; sulco perpendicular do manto bem desenvolvido; lamela interna do manto se estendendo externamente na região do manto anterior. Essas diferenças podem ser ecofenótipos ou diferenças entre as populações com certo grau de isolamento da América do Sul, que podem ser elucidados por estudos filogeográficos subsequentes.(AU)

Use of eugenol as an anaesthetic for Geophagus brasiliensis juveniles / Utilização de eugenol como anestésico em juvenis de Geophagus brasiliensis

The eugenol is the active ingredient of clove oil and it has shown to be effective and safe as fish anesthetic. In this study were evaluated the effects of different concentrations of eugenol for anesthesia, recovery time, blood glucose and hematocrit percentage of pearl cichlid (Geophagus brasiliensis) juveniles. Concentrations of 50, 80, 100, 120, 150, 170 and 200 mg L-1 eugenol were evaluated in terms of time to achieve the different stages of anesthesia and recovery in a completely randomized design (CRD) with 12 repetitions. These results were tested using the Kruskal-Wallis test with subsequent Dunn test. The evaluated concentrations had anesthetic action of the deep induction 172.57 ± 25 s (50 mg L-1) and the period of full recovery of 516.25 ± 102 s (200 mg L-1), with statistical difference between the treatments at all the stages. The eugenol effect on blood glucose and on hematocrit percentage at 0 h after deep anesthesia was evaluated for concentrations of 0; 50; 80; 100; 150; 200 mg L-1, in a completely randomized design with five replications, and the results were assessed by One-Way ANOVA. Glucose and percentage of hematocrit: no statistically significant differences (P>0.05) were observed for these variables.All concentrations of eugenol showed to be effective as an anesthetic for G. brasiliensis and did not affect the survival, blood glucose and the percentage of hematocrit. To minimize adverse effects and achieve faster recovery is indicate the use of 50-80 mg L-1 of eugenol for pearl cichlid juveniles.

O eugenol, substância ativa do óleo de cravo, tem demonstrado ser eficiente e seguro como anestésico para peixes. Neste estudo foram avaliados os efeitos de diferentes concentrações de eugenol na anestesia, tempo de recuperação, glicemia e percentual de hematócrito de cará (Geophagus brasiliensis). Concentrações de 50, 80, 100, 120, 150, 170 e 200 mg L-1 de eugenol foram avaliadas em relação aos tempos para atingir os diferentes estágios de anestesia e de recuperação, em desenho inteiramente casualizado (DIC), com 12 repetições. Os resultados foram analisados pelos testes de Kruskal-Wallis e teste Dunn. As concentrações avaliadas produziram ação anestésica em período de indução profunda de 172,57 ± 25 s (50 mg L-1) e no período de total recuperação de 516,25 ± 102 s (200 mg L-1), com diferença estatística entre os tratamentos para todas as fases avaliadas. Foi avaliado o efeito do eugenol sobre a glicose no sangue e sobre o percentual de hematócrito, em 0 h após anestesia profunda, nas concentrações 0, 50, 80, 100, 150 e 200 mg L-1, em DIC com cinco repetições, e os resultados avaliados através de ANOVA uma via. Não foram observadas diferenças estatísticas significativas (P>0,05) para glicose e hematócrito. Todas asconcentrações de eugenol avaliadas apresentaram eficiência como anestésico para G. brasiliensis enão afetaram a sobrevivência, a glicose sanguínea e o percentual de hematócrito. Para minimizarefeitos adversos não avaliados e obter recuperação mais rápida, indica-se o uso de 50 a 80 mg L-1 deeugenol para juvenis de carás.

Anatomical differences among specimens of Pinctada imbricata Rõding, 1798 from different South American localities / Diferenças anatômicas entre espécimes de Pinctada imbricata Rõding, 1798 de diferentes localidades da América do Sul

In the present study, we compared the internal and external anatomy of pearl oyster (Pinctada imbricata Rõding, 1798) from some South American localities, including Venezuela and several regions of Brazil. The anatomical data shows non-geographical variations characterized by variable outline in adults, different degrees of posterior auricle shell development and mantle papillae ranging from normal to digitiform. The geographical variations can be divided into two major groups: the Venezuelan group presents a more folded mantle; pallial muscle grouped in anterior and median-posterior sets; poorly-developed perpendicular mantle groove; inner lamella not extended into the anterior mantle. Brazilian group specimens present a smoother mantle, with less clear separation between anterior and posterior mantle muscle groups; externally-developed perpendicular groove; inner lamella extension developed in anterior mantle. These differences may represent ecophenotypes or differences among isolated South American populations, which may be elucidated by subsequent phylogeographic studies.

No presente estudo comparou-se a anatomia da ostra perlífera (Pinctada imbricata Rõding, 1798) de algumas localidades da América do Sul, incluindo a Venezuela e várias regiões do Brasil. Foram encontradas variações não geográficas e geográficas. As variações não geográficas foram caracterizadas por adultos com contorno bem variável, diferentes graus de desenvolvimento da aurícula posterior e papilas da lamela interna do manto variando de normal a digitiformes. Variações geográficas podem ser divididas em dois grandes grupos: o grupo venezuelano apresentou um manto mais pregueado; musculatura palial agrupada em dois conjuntos de feixes um anterior e outro mediano-posterior; sulco perpendicular do manto pouco desenvolvido. Espécimes dos grupos brasileiros apresentaram um manto menos pregueado, com separação menos nítida entre os feixes musculares paliais anterior e posterior do manto; sulco perpendicular do manto bem desenvolvido; lamela interna do manto se estendendo externamente na região do manto anterior. Essas diferenças podem ser ecofenótipos ou diferenças entre as populações com certo grau de isolamento da América do Sul, que podem ser elucidados por estudos filogeográficos subsequentes.