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A differential diet with royal jelly (RJ) during early larval development in honeybees shapes the phenotype, which is probably mediated by epigenetic regulation of gene expression. Evidence indicates that small molecules in RJ can modulate gene expression in mammalian cells, such as the fatty acid 10-hydroxy-2-decenoic acid (10-HDA), previously associated with the inhibition of histone deacetylase enzymes (HDACs). Therefore, we combined computational (molecular docking simulations) and experimental approaches for the screening of potential HDAC inhibitors (HDACi) among 32 RJ-derived fatty acids. Biochemical assays and gene expression analyses (Reverse Transcriptase – quantitative Polymerase Chain Reaction) were performed to evaluate the functional effects of the major RJ fatty acids, 10-HDA and 10-HDAA (10-hydroxy-decanoic acid), in two human cancer cell lines (HCT116 and MDA-MB-231). The molecular docking simulations indicate that these fatty acids might interact with class I HDACs, specifically with the catalytic domain of human HDAC2, likewise well-known HDAC inhibitors (HDACi) such as SAHA (suberoylanilide hydroxamic acid) and TSA (Trichostatin A). In addition, the combined treatment with 10-HDA and 10-HDAA inhibits the activity of human nuclear HDACs and leads to a slight increase in the expression of HDAC-coding genes in cancer cells. Our findings indicate that royal jelly fatty acids collectively contribute to HDAC inhibition and that 10-HDA and 10-HDAA are weak HDACi that facilitate the acetylation of lysine residues of chromatin, triggering an increase in gene expression levels in cancer cells.

Exponential model for population growth (exponential model) is a foundation to evaluate population dynamics in Population Ecology field. Here, we used a didactic experiment to teach exponential model for an undergraduate course of Population Ecology. We built nine populations of weevils with three different initial population sizes: eight, 16, and 32 individuals with three replicates each. We provided equal food resource availability, and counted their population sizes weekly for 12 weeks. We estimated the intrinsic growth rate (i.e., r parameter), by trials and errors with an exponential model build in an Excel spreadsheet. The population growth rate (i.e., dN/dt parameter) was estimated using r values. Replicates with eight and 16 individuals reached the highest values of r and dN/dt, while replicates with 32 individuals reached the lowest values. Beyond of exponential model, two density dependency issues acting in populations were observed. First, in the lowest initial population sizes we observed the effect of demographic stochasticity acting in both r and dN/dt in one of the three populations. Second, we observed the intraspecific competition reducing r values in largest initial populations. Therefore, we highlight the importance of didactic experiment into learning exponential model in Population Ecology course, both for teaching and learning practices.

This study developed a structured fruit cube (FC) snack using only natural ingredients, specifically red grape and apple, without hydrocolloids and sucrose. After development, physicochemical characterization and analysis of phenolic compounds (PCs), including anthocyanins, flavonols, and hydroxycinnamic acid derivatives, using HPLC-DAD-ESI-MS/MS, were conducted. Sensory quality was also assessed through an acceptance and sensory profile analysis using the rate-all-that-apply methodology. The results showed that the FC had physicochemical characteristics similar to other structured fruits that use hydrocolloids. Additionally, they presented a complex composition of PCs, predominantly including anthocyanins derived from malvidin (tri-substituted methoxylated anthocyanins), notably cumarylated ones. Flavonols compounds comprised the 3-glucoside series of myricetin, quercetin, laricitrin, kaempferol, isorhamnetin, and syringetin; the 3-galactoside series of myricetin and quercetin; and the 3-glucuronic acid series of myricetin and quercitin, along with rutin. The presence of caftaric acid, coutaric acid, fertaric acid, and p-coumaroyl-glucose was also detected, alongside caffeic acid-O-glucoside 1, caffeic acid-O-glucoside 2, chlorogenic acid, 4-O-p-coumaroylquinic acid, and dicaffeoylquinic acid. In conclusion, the selection of natural ingredients was technologically suitable for obtaining an FC. Despite using conventional drying at 60 °C, the product showed notable concentrations of PCs and also achieved great sensory acceptance.

This study explores the application of random matrices to track chaotic dynamics within the Chirikov standard map. Our findings highlight the potential of matrices exhibiting Wishart-like characteristics, combined with statistical insights from their eigenvalue density, as a promising avenue for chaos monitoring. Inspired by a technique originally designed for detecting phase transitions in spin systems, we successfully adapted and applied it to identify analogous transformative patterns in the context of the Chirikov standard map. Leveraging the precision previously demonstrated in localizing critical points within magnetic systems in our prior research, our method accurately pinpoints the Chirikov resonance overlap criterion for the chaos boundary at K≈2.43, reinforcing its effectiveness. Additionally, we verified our findings by employing a combined approach that incorporates Lyapunov exponents and bifurcation diagrams. Lastly, we demonstrate the adaptability of our technique to other maps, establishing its capability to capture the transition to chaos, as evidenced in the logistic map.

Abstract Salvia lachnostachys Benth is native to Brazil and has anti-inflammatory, anti-arthritic, cytotoxic, antitumor, and antihyperalgesic activities. The population, including pregnant women, consume this plant to treat pain, inflammation, flu, spasms, insomnia, and depression, mainly. There are no safety reports on the use of this plant during pregnancy. The present study aimed to evaluate the effects of S. lachnostachys ethanolic extract (EESl) on reproductive performance, embryofetal development, and DNA integrity of pregnant female mice. Pregnant females were randomly divided into three experimental groups (n = 10): The Control group was treated with a vehicle, and treatment groups were administered with EESl at 100 and 1000 mg/kg, respectively. Treatment occurred by gavage throughout the gestational period until day 18. Afterward, reproductive performance, embryofetal development, and DNA integrity parameters were evaluated. The results indicated that EESl did not alter any reproductive performance parameters. However, it changed embryofetal outcome through reduced placental weight (EESl 100 mg/kg), decreased fetal weight (EESl 100 and 1000 mg/kg), and increased frequency of small for gestational age fetuses (EESl 1000 mg/kg). In addition, EES1 increased the frequency of external, visceral, and skeletal malformations. Because of the above, it is considered that EESl is not maternotoxic, does not alter reproductive performance, but does alter embryofetal development. Its use in the gestational period is not indicated due to its teratogenic potential.

Abstract Leaf-cutting ants of the genera Atta and Acromyrmex (Hymenoptera: Formicidae) are the most important pests in forest and agricultural plantations and livestock. Toxic baits are the main method to manage these insects. The objective was to determine whether the behavior of allogrooming, touch, and self-grooming among Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae) workers disperse the fungicide quinone inside inhibitor and whether this product is toxic to them. This fungicide was applied, topically, in groups of workers and the social interactions between them and their mortality with and without the fungicide were evaluated. The interactions and the quinone inside inhibitor fungicide contamination increased with the number of leaf-cutting ant workers per group. Excessive touches, with subsequent allogrooming, and self-grooming among the ant workers dispersed the quinone inside the inhibitor fungicide causing 100% mortality and indicating its toxicity to this insect. The hypothesis that social interactions contaminated ant colony mates and the toxicity of the fungicide quinone inside inhibitor to workers of the leaf-cutting ant A. sexdens rubropilosa was proven.

Abstract The objective of this work was to manufacture pizza dough, truffle, and cake using the paste of a by-product from the vinification of 'BRS Violeta' grape, as well as to determine some bromatological characteristics of these products. The by-product was pressed to remove excess must and crushed to obtain the paste. The paste, pasteurized at 80°C for 3 min and frozen at -18°C, was characterized for total phenolic compounds (TPC), total monomeric anthocyanins (TMA), and dietary fiber. The food products were characterized for the following parameters: moisture, energy value, and protein, lipid, ash, dietary fiber, total carbohydrates, and TPC contents. The contents found in the paste were: 326 mg GAE 100 g-1, for TPC; 185 mg mv35diglc 100g-1, for TMA; and 10 g 100 g-1, for dietary fibers. Based on the centesimal compositions of the food products, the pizza dough and truffle can be considered as a source of fiber and protein, respectively. The products show TPC contents between 51 and 63 mg GAE 100 g-1. It is possible to prepare food products of good nutritional quality, using grape by-product paste, to minimize waste in the field.

Random matrix theory, particularly using matrices akin to the Wishart ensemble, has proven successful in elucidating the thermodynamic characteristics of critical behavior in spin systems across varying interaction ranges. This paper explores the applicability of such methods in investigating critical phenomena and the crossover to tricritical points within the Blume–Capel model. Through an analysis of eigenvalue mean, dispersion, and extrema statistics, we demonstrate the efficacy of these spectral techniques in characterizing critical points in both two and three dimensions. Crucially, we propose a significant modification to this spectral approach, which emerges as a versatile tool for studying critical phenomena. Unlike traditional methods that eschew diagonalization, our method excels in handling short timescales and small system sizes, widening the scope of inquiry into critical behavior.

Introduction and Objectives: Hepatopulmonary Syndrome (HPS) is a chronic and irreversible disease caused by systemic changes associated with portal hypertension, which greatly compromises patients' expectations and quality of life. It is associated with an increase in morbidity and mortality regardless of the degree of liver dysfunction. Data on the accuracy of the diagnosis of HPS in cirrhosis is limited. This study aimed to analyze the prevalence of HPS in cirrhotic patients at our service and to correlate it with oxygen saturation (SatO2) using a pulse oximeter to evaluate if this is useful as a screening test for HPS. Materials and Methods: A prospective study was conducted in consecutive patients with hepatic cirrhosis, followed up on demand and selected from November 1, 2021, to May 31, 2022. All the patients underwent an oxygen saturation measurement by pulse oximetry and arterial blood gas analysis. The relationship between SatO2 and HPS was assessed. Results: a total of 29 patients with clinically confirmed cirrhosis were analyzed, 16 (56%) male patients. Twenty-six (90%) patients had no symptoms related to HPS and 5 (17%) had arterial blood gas analysis criteria for HPS. The alcoholic etiology of cirrhosis was the most prevalent (52%). The mean age was 59 years. Twenty-two (76%) patients were classified as Child Pugh A and 7 (24%) as Child Pugh B. The relationship between HPS and SatO2 did not show statistical significance. Conclusions: Oxygen saturation alone was not able to detect HPS in the sample of cirrhotic patients. More accurate methods for screening and diagnosis of the syndrome should be used.

Introduction and Objectives: Identifying independent risk factors for adverse outcomes in patients infected with severe acute respiratory syndrome coronavirus 2 can support prognostication, resource utilization, and treatment. The presenting symptoms of this virus are variable and the evolution and clinical significance of abnormal liver chemistries on outcomes in patients with coronavirus disease 2019 (COVID-19) is not well characterized. This study aimed to evaluate if aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels could predict disease severity in patients with COVID-19. Materials and Methods: a retrospective, observational and cross-sectional study was carried out with data from the medical records of patients who had positive SARS-CoV2 nasal swabs, were over 18 years of age and were admitted consecutively and under free demand at a Brazilian academic hospital from April 1 to May 31, 2021. The characteristics of liver abnormalities and outcomes of patients with COVID-19 were compared. Results: altogether, 222 patients were enrolled, three patients with cirrhosis and 82% with abnormal liver chemistries during hospitalization. Of these, 20% showed transaminases >5 times the upper limit of normal (ULN). The most prevalent liver abnormality was AST. The increase in transaminases was directly proportional to the higher rates of intensive care unit admission, longer hospital stays, higher rates of vasoactive drug use and greater pulmonary involvement in its severe forms. We found that elevations of transaminases >5 times the ULN, at any time during hospitalization were associated with increased mortality. Conclusions: coronavirus 2 hepatitis may lead to poor outcomes in patients who are hospitalized for the disease. Therefore, monitoring liver chemistries, especially AST is necessary for hospitalized patients with COVID-19.

Dark chocolate dragée confectionary was made with BRS Clara raisins pre-treated with extra virgin olive oil (EVOO). The evaluation of the changes in the phenolic composition (flavonols, hydrocinnamic acid derivatives (HCADs), stilbenes and flavan-3-ol monomers, dimers, and proanthocyanidins (PAs)) resulting from the covering process showed that the chocolate coating was responsible for an increase in the concentrations of flavan-3-ols and PAs when compared to just the raisins. For the flavonols and HCADs, a reduction in the total concentration of compounds was observed when comparing the dragées to the raisins. Furthermore, there was a strong influence of chocolate in the qualitative profile with the emergence of new compounds (quercetin-3-pentoside, kampfterol-3-rutinoside, p-coumaric acid, and caffeoyl-aspartate). The combination of these ingredients (raisins and chocolate) resulted in a dark chocolate coated raisin (DC) with good sensory acceptance and a more complex phenolic composition that may positively contribute to its functional quality.

O objetivo deste artigo é analisar como, por meio do jornal Versus, periódico alternativo, que circulou entre 1975 e 1979, pode-se observar uma cultura política de oposição e resistência em um contexto no qual vários países da América Latina passavam por regimes de exceção. A temática da América Latina foi um dos aspectos a distinguir o jornal dos outros periódicos, em um enfoque que procurou utilizar do significante da morte como alegoria de uma época de repressão e perseguições políticas. Posteriormente, o tema da América Latina tornou-se uma das divergências entre os produtores do jornal. Tal divergência deu-se entre o grupo do idealizador do periódico, Marcos Faerman, e a organização política Convergência Socialista, que posteriormente exerceu influência e controle sobre o periódico, passando a priorizar temas sobre a política brasileira em detrimento da temática da América Latina.

Pancreatic cancer remains a disease that is very difficult to treat. S100 proteins are small calcium binding proteins with diverse intra- and extracellular functions that modulate different aspects of tumorigenesis, including tumor growth and metastasis. High mobility group box 1 (HMGB1) protein is a multifaceted protein that also actively influences the development and progression of tumors. In this study, we investigate the possible correlations, at the transcript level, between S100s and HMGB1 in pancreatic cancer. For this purpose, we calculated Pearson’s correlations between the transcript levels of 13 cancer-related S100 genes and HMGB1 in a cDNA array containing 19 pancreatic cancer tumor samples, and in 8 human pancreatic cancer cell lines. Statistically significant positive correlations were found in 5.5% (5 out of 91) and 37.4% (34 of 91) of the possible S100/S100 or S100/HMGB1 pairs in cells and tumors, respectively. Our data suggest that many S100 proteins crosstalk in pancreatic tumors either with other members of the S100 family, or with HMGB1. These newly observed interdependencies may be used to further the characterization of pancreatic tumors based on S100 and HMGB1 transcription profiles.

Orchidaceae is the most diverse botanical family in the city of Rio de Janeiro, Brazil, with 79 gene-ra and 250 species. Vegetation in Rio de Janeiro is mostly restricted to small fragments of Atlantic Forest, many of which are located within conservation units and act as refuges for flora. Some of the best-known postcards of the city, such as Corcovado and Sugar Loaf mountains, and the Christ the Re-deemer statue, are located within urban conservation units. This work presents the results of a floristic-taxonomic study of Orchidaceae in the Parque Estadual da Chacrinha (PE Chacrinha), a state park located extremely near the famous Copacabana beach in the heart of Rio de Janeiro. Brief morpholo-gical descriptions of the species are provided and an identification key for the orchids of PE Chacrinha is presented, based mainly on vegetative morphological characters. Orchidaceae of PE Chacrinha is represented by thirteen genera and 16 species, most of which restricted to Brazil, seven of them are also endemic to the Atlantic Forest, or South America and occur as terricolous or rupicolous. We highlighted the occurrences of Acianthera limae, Epidendrum ammophilum and Prescottia spiranthophylla, spe-cies that grow exclusively or predominantly on rocky outcrops. With these findings, our goal is to raise awareness among the local population about the importance of conserving the regional flora; stimulate visits to PE Chacrinha and promote the inclusion of this conservation unit in the tourist itinerary of the city of Rio de Janeiro.

Abstract Background Atrazine is one of the most widespread chlorinated herbicides, leaving large bulks in soils and groundwater. The biodegradation of atrazine by bacteria is well described, but many aspects of the fungal metabolism of this compound remain unclear. Thus, we investigated the toxicity and degradation of atrazine by 13 rainforest basidiomycete strains. Results In liquid medium, Pluteus cubensis SXS320, Gloelophyllum striatum MCA7, and Agaricales MCA17 removed 30, 37, and 38%, respectively, of initial 25 mg L− 1 of the herbicide within 20 days. Deficiency of nitrogen drove atrazine degradation by Pluteus cubensis SXS320; this strain removed 30% of atrazine within 20 days in a culture medium with 2.5 mM of N, raising three metabolites; in a medium with 25 mM of N, only 21% of initial atrazine were removed after 40 days, and two metabolites appeared in culture extracts. This is the first report of such different outcomes linked to nitrogen availability during the biodegradation of atrazine by basidiomycetes. The herbicide also induced synthesis and secretion of extracellular laccases by Datronia caperata MCA5, Pycnoporus sanguineus MCA16, and Polyporus tenuiculus MCA11. Laccase levels produced by of P. tenuiculus MCA11 were 13.3-fold superior in the contaminated medium than in control; the possible role of this enzyme on atrazine biodegradation was evaluated, considering the strong induction and the removal of 13.9% of the herbicide in vivo. Although 88% of initial laccase activity remained after 6 h, no evidence of in vitro degradation was observed, even though ABTS was present as mediator. Conclusions This study revealed a high potential for atrazine biodegradation among tropical basidiomycete strains. Further investigations, focusing on less explored ligninolytic enzymes and cell-bound mechanisms, could enlighten key aspects of the atrazine fungal metabolism and the role of the nitrogen in the process.

Neste trabalho, foi planejada a síntese de lipídeos resorcinólicos análogos as citosporonas utilizando métodos clássicos de síntese orgânica. O objetivo principal foi à preparação dos compostos: ácido 2,4-dihidróxi-6-octil-benzóico (6) e 2,4-diidróxi-6-(8-oxooctil)-benzóico (7). Foram estudadas rotas de síntese visando à produção desses compostos, foi possível obtenção de três intermediários avançados, com sucesso: 2,4 dimetóxi-6-octil-benzoato de etila (8), 2-hidróxi-4-metóxi-6-octil-benzoato de etila (9) e ácido 2-hidróxi-4-metóxi-6-octil-benzóico (10), os quais tiveram suas estruturas determinadas por técnicas de espectroscopia de RMN de 1H e de 13C, e no caso de (10) incluindo técnicas bidimensionais (HSQC e HMBC).

A ideia que se faz das pesquisas arqueológicas no Brasil no século XIX ainda não é clara. O objetivo deste artigo é fazer um levantamento da atividade arqueológica no Brasil e sua relação com as instituições museológicas em seus primeiros cem anos centrando-nos no período do reinado de D. Pedro II quando a arqueologia brasileira tem seu primeiro florescimento e alguns dos museus ainda hoje existentes têm sua origem. Podemos dividir os cem primeiros anos da nossa arqueologia em três períodos: um período formativo; uma segunda fase mais científica com missões estrangeiras e uma terceira fase centrada no Museu Nacional e que termina com a República.

In this work, we have tested individual and combination of applications of ozonolysis and liquid hot water (LHW) to pretreat sugarcane bagasse (SCB) for the removal of enzyme and/or microbial inhibitors and generation of potential value-added chemicals. A solid content with 80% cellulose and a liquid phase (liquor) rich in phenolic derived compounds (3 g.L−1) from lignin, sugars (>20 g.L−1), and other compounds, such as furfural and hydroxymethylfurfural (HMF), were generated. Maximal (59%) glucan conversion occurred in the presence of double-pretreated bagasse, which had 32–50% more glucan available than the samples that were individually LHW or ozone-pretreated, resulting in maximal ethanol production (92% after 42 h) from double-pretreated SCB enzyme hydrolyzate. In summary, this work showed that ozone reacts effectively with lignin without the use of any other chemical reagent, and LHW pretreatment, followed by a washing step, was effective in solubilizing and cleaning up the fiber enzyme and microbial inhibitory compounds with ozone being effective against phenolics. Moreover, the generated cellulose-rich substrate is readily fermentable. The acidic liquor fraction removed by sequential washings and containing mainly sugars and phenolic compounds may be evaluated for use in green chemistry bioconversions processes.

Piper glabratum Kunth is a plant traditionally used to treat pain and inflammation in the Mato Grosso do Sul, Brazil. Even pregnant women consume this plant. Toxicology studies of the ethanolic extract from the leaves of P. glabratum (EEPg) could establish the safety of popular use of P. glabratrum. Thus, the effects of the ethanolic extract of leaves of P. glabratum (EEPg) on the reproductive performance and embryofetal development of Swiss mice were evaluated. Pregnant female mice were treated with 100, 1000 and 2000 mg/kg throughout the gestational period by gavage (p.o). The control group received the EEPg vehicle (Tween 80–1%) in the proportion of 0.1 mL/10 g (p.o.). The results demonstrated that EEPg has low maternal toxic potential and does not alter the reproductive performance of females. However, it altered embryofetal development and caused fetal weight reduction (increasing the frequency of small-for-gestational-age fetuses) at the two highest doses. In addition, it interfered with placental weight, placental index and placental efficiency. The frequency of visceral malformations increased by 2.8 times for the lowest dose of EEPg, and skeletal malformations increased by 2.48, 1.89 and 2.11 times for doses of 100, 1000 and 2000 mg/kg of EEPg, respectively. It is noteworthy that 100% of the offspring treated with EEPg showed changes in the ossification process. Thus, it is considered that the EEPg has low maternal toxic potential; it does not alter the reproductive performance of females. However, it is teratogenic and interferes, mainly, in the ossification process, and therefore its use is contraindicated in the gestational period.

3-heptylidene-4,6-dimethoxy-3H-isobenzofuran-1-one (Phthalide 1) is the precursor of three resorcinol lipids that have been described as potential chemotherapeutic agents and capable of potentiating the effects of cyclophosphamide. In this study, we evaluated the genotoxic potential, cell-killing potential, and interactions with cyclophosphamide and cisplatin of phthalide 1. Twelve groups were created from 120 mice: Negative Control, cyclophosphamide (100 mg/kg), cisplatin (6 mg/kg), Phthalide 1 (5, 10 and 20 mg/kg), and associations of 1 with cyclophosphamide and 1 with cisplatin. The results demonstrate that 1 increases (p < 0.05) the frequency of chromosomal damage, liver and kidney cell death, and splenic phagocytosis. The association of 1 with cyclophosphamide and cisplatin demonstrated a chemopreventive effect and, therefore, a reduction (p < 0.05) in the frequency of chromosomal damage. However, cell death and splenic phagocytosis did not suffer significant variations. As a result of the above, 1 has potential chemotherapeutic application and may be a candidate for developing a new generation of chemotherapeutics. In addition, it has characteristics to be used as a chemotherapy adjuvant in association with cyclophosphamide and cisplatin since it increases the frequency of cell death induced by chemotherapy. We also reported that the chemopreventive effect of 1, in association with cyclophosphamide and cisplatin, can prevent adverse effects (induction of DNA damage in non-tumor cells) without interfering with the mode of action of chemotherapy drugs and, therefore, without reducing the induction of cell death.

Gomphrena celosioides is a native Brazilian plant found in the State of Mato Grosso do Sul. It is used in folk medicine to treat kidney diseases, skin diseases, infections, rheumatism, gastrointestinal diseases, and respiratory diseases. It is also used as an abortifacient. To evaluate the effects of the ethanolic extract of Gomphrena celosioides (EEGc) on reproductive performance, embryo development, and chromosome stability, Swiss mice were randomly divided into experimental groups (n = 10). The animals in the control group received the vehicle Tween 80–1% in the proportion of 0.1 mL/10 g of body weight orally, from the first to the 18th gestational day. The animals in the treatment groups received the EEGc (100, 1000, and 2000 mg/kg) from the first to the 18th gestational day. The animals underwent evaluations of their reproductive performance and embryofetal development. The results showed that the EEGc did not change the animals’ final weight, weight gain, uterine weight, or net weight gain. The evaluation showed that the absolute and relative organs’ weights did not vary between the different experimental groups. In addition, the EEGc did not change the numbers of implants, live fetuses, dead fetuses, or fetal resorptions. There were no differences in post-operative loss rates, implantations, or resorptions, nor were there differences in fetal viability or sex ratio. The use of the EEGc did not result in different frequencies of malformations. In addition, the EEGc did not alter the frequency of chromosomal damage or frequency of micronuclei. Based on our findings, we considered the extract of Gomphrena celosioides to be safe for use during pregnancy, although some parameters indicated caution in its use.

Considering the toxic action of P. aquilinum bracken for vertebrates, its insecticidal activity and potential use in agricultural pest control was verified, testing its effects on S. frugiperda. Crude ethanolic extract was made with the aerial part of P. aquilinum, being incorporated into artificial diet (control or extract-free, 1% and 2%) with 50 replicates (caterpillars). There was significant mortality (34% and 86%) at concentrations of 1% and 2%, respectively, compared to control (10%). In treatments at 1% (20.03 days) and 2% (20.42 days), larval stage prolongation (13.51 days) was observed in the control treatment. On the 3rd, 6th, 9th and 12th days after treatment, there was weight reduction, and the 2% treatment resulted in larvae 73% lighter than the control did at day 12. The pupae of the 2% treatment were lighter than the others. In conclusion, 1% and 2% of P. aquilinum ethanolic extract extended the larval cycle, decreased the larvae’s and pupae’s weight, and, at a concentration of 2%, caused effective mortality of S. frugiperda.

ABSTRACT Chemical control using toxic baits containing the active ingredient sulfluramid at 0.3% (w/w) is the main method for controlling leaf-cutting ants of the genera Atta and Acromyrmex. However, since 2009, when sulfluramid was included in Annex B of the Stockholm Convention on Persistent Organic Pollutants, there has been an intense search for new methods that are efficient in controlling these insects. Among said new methods, biological control using pathogenic fungi has shown promising results in laboratory conditions. The objective of this study, given the context presented, was to assess the potential of the fungi Beauveria bassiana and Trichoderma harzianum in controlling Atta sexdens. Colonies of A. sexdens were exposed to the fungi by means of formulated baits provided in a foraging chamber, or of suspensions sprayed on the fungus garden, and had their behavioral changes recorded for 21 days. For both formulations, concentrations of 10 and 20% (w/w) of the fungi being studied were used. The results allowed concluding that baits containing 10 and 20% (w/w) of the fungi B. bassiana and T. harzianum were not efficient in controlling colonies of A sexdens. On the other hand, spraying suspensions of 20% (w/w) of B. bassiana and 10% and 20% (w/w) of T. harzianum was efficient and resulted in 100% mortality of the colonies 11, 9 and 7 days after application, respectively. These findings indicate that the fungi B. bassiana and T. harzianum are promising as agents for the control of A. sexdens colonies, when sprayed on the fungus garden, although there are still some challenges as to their use related to the development of technologies for the application of the pathogen.

A protease from the fungus Mucor subtilissimus URM 4133, capable of producing bioactive peptides from goat casein, was purified. SDS-PAGE and zymography showed a molecular mass of 30 kDa. The enzyme was active and stable in a wide pH range (6.0–10.5) and (5.0–10.5), respectively. Optimum temperature was at 45–50 °C and stability was above 80 % (40 °C/2 h). Activity was not influenced by ions or organic substances (Triton, Tween, SDS and DMSO), but was completely inhibited by PMSF, suggesting that it belongs to the serine protease family. The Km and Vmax were 2.35 mg azocasein.mL-1 and 333.33 U.mg protein-1, respectively. Thermodynamic parameters of irreversible denaturation (40–60 °C) were enthalpy 123.63 – 123.46 kJ.mol-1, entropy 120.24–122.28 kJ.mol-1 and Gibbs free energy 85.97 – 82.45 kJ.mol-1. Any peptide sequences compatible with this protease were found after analysis by MALDI-TOF, which suggests that it is a new serine protease.

Leaf-cutting ants are widely distributed in Brazil, particularly species of the genus Atta. We therefore described the occurrence of leaf-cutting and grass-cutting ant species of the genus Atta. Five routes comprising some of the main highways in the South, Southeast, Center-West, and North of Brazil were sampled, in addition to ants received from other 82 municipalities, composing 300 municipalities sampled. This is the first comprehensive study of Atta in Brazil. The following species were found: A. laevigata, A. capiguara, A. sexdens rubropilosa, A. sexdens piriventris, A. sexdens sexdens and A. cephalotes. Atta laevigata and A. capiguara were the species present in the largest number of the Brazilian municipalities sampled. Atta laevigata assumed the position of species of greatest occurrence in the Brazilian territory. Atta sexdens piriventris was only recorded in the southern region of Brazil. Atta bisphaerica presented lower expansion than A. capiguara. Atta cephalotes and Atta opaciceps are species of very restricted occurrence. Southeastern region was characterized by the occurrence of A. capiguara and A. laevigata. Atta laevigata exhibited a generalized pattern of occurrence in the Center-West and North. Our study contributes to a better understanding of the so far unknown occurrence of leaf-cutting and grass-cutting ants within Brazil.

The entropy of the Higgs boson decay probabilities distribution in the Standard Model (SM) is maximized for a Higgs mass value that is less than one standard deviation away from the current experimental measurement. This successful estimate of the Higgs mass encourages us to propose tests of the Maximum Entropy Principle (MEP) as a tool for theoretical inferences in other instances of Higgs physics. In this letter, we show that, irrespective of the extension of the SM predicting a new Higgs boson decay channel, its branching ratio can be inferred to be around 7% in such a way that the new entropy of decays still exhibits a maximum at the experimental Higgs mass. This 7% rule can be tested whenever a new Higgs decay channel is found. In order to illustrate the MEP predictions, we apply the MEP inference to Higgs portal models, Higgs-axion interactions, lepton flavor violating decays of the Higgs boson, and a dark gauge boson model.

Cellulases are essential for the hydrolysis of lignocellulosic materials in the production of second generation ethanol. Solid-state cultivation is a process that provides high concentrations of enzymes that can be used in this hydrolysis. The objectives of this work were to produce cellulases by cultivating the fungus Myceliophthora thermophila I-1D3b in a packed bed bioreactor with sugarcane bagasse (SCB) and wheat bran (WB) as substrate and to evaluate the efficiency of the enzymatic extract in the hydrolysis of SCB in natura (BIN) and pretreated with ozone, alkali and ultrasound (BOU). The conditions for enzyme production in the bioreactor were SCB:WB at a ratio of 2.3:1 (w/w), 75 % moisture content; 45 ºC; aeration rate 240 L h-1 and 96 h. The enzyme production was evaluated by endoglucanase, xylanase, filter paper (FPU) and ?-glycosidase activities. For the application of the enzymes, a central composed response surface design with 5 repetitions of the central point was used, taking enzyme volume and hydrolysis time as factors. Such cultivation yielded the following enzymatic activities: 723 U gss-1 of endoglucanases, 2024 U gss-1 of xylanase, 12.6 U gss-1 of FPU and 41 U gss-1 of ?-glucosidase. The results of the application tests indicated the best conditions as 7.0 ml of the enzyme extract (4.2 FPU) and 6 hours for BIN and BOU. The best cellulose-glucose conversions were obtained for BOU, reaching 32.1 % at 65 ºC. In conclusion, the enzyme production in the packed bed bioreactor was efficient and BOU pretreatment improved the hydrolysis of biomass, increasing the efficiency of conversion of cellulose to glucose.

Resorcinolic lipids, a class of bioactive amphiphilic molecules found widely in nature, hold potential for a variety of biological and industrial applications. This report describes the synthesis of three bioactive structural analogues of resorcinolic lipids, obtained by subjecting ethyl (E)-2-undecenoate and ethyl acetoacetate to a Michael reaction in the presence of sodium ethoxide to generate a Michael adduct, followed by cyclization in the reaction medium. Ethyl 2-octyl-4,6-dioxocyclohexanecarboxylate (7) was thus produced with a 60% yield. To perform an aromatization step, 7 was subsequently treated with I2 in methanol under reflux, producing a combined 80% yield of 2,4-dimethoxy-6-octyl-ethyl benzoate (1) and 2-hydroxy-4-methoxy-6-octyl-ethyl benzoate (2) at a 7:3 ratio, respectively. 2-Hydroxy-4-methoxy-6-octyl-benzoic acid was obtained with a 60% yield by treating 1 with BBr3/CHCl3. The structures of the synthesized compounds and intermediates were elucidated by 1H and 13C NMR spectroscopy, employing two-dimensional techniques (HSQC and HMBC). DOI: http://dx.doi.org/10.17807/orbital.v12i2.237

This study evaluates the properties of chitosan (CS) membranes modified with different percentages (0.5%, 3%, and 5% w/w) of a graphene-based material. Graphene oxide (GO) and reduced graphene oxide (RGO) were obtained by the chemical exfoliation of graphite and thermal reduction. Then, they were characterized by electrical conductivity measurements, FESEM, XRD, AFM, and Raman spectroscopy. The composites’ morphology was evaluated by FESEM. The degree of swelling over a 48 h period and mass loss behavior in phosphate-buffered saline solution for up to 70 days were also studied. The hydrophilicity of the CS and CS/graphene nanocomposites was examined by water contact angle. The graphene materials showed small stacks (6-8 sheets) with low defect density and nanoscale thickness (1.3-5.9 nm). The dispersion of the graphene material in the CS matrix significantly decreased the degree of swelling (460%) but did not modify the hydrolytic degradation process and the hydrophilicity of membranes.

During foraging, worker ants are known for making use of many information sources to guide themselves in external environments, especially individual (memory) and social (trail pheromone) information. Both kinds of information act in a synergic way, keeping the foraging process efficient and organized. However, when social and individual information is conflicting face a trail bifurcation, it is necessary to establish a hierarchical order so prioritizing one of them. This study aims to verify which information (social or individual) is prioritized by Acromyrmex subterraneus workers when facing a bifurcation in a Y-trail system. Only one branch of the Y-trail leads to food resource and it had a section covered by filter paper where trail pheromone was deposited by workers. Pheromone deposition was here estimated by worker flow. After an individually marked forager (target-worker) made 1, 3 or 5 trips to the food resource, the filter paper was transferred to the branch which did not lead to the food. The time spent by target workers on branch selection and their right choice (branch with food) frequency were registered. Regardless of the target worker's previous trips to the resource, right choice frequency stood over 70%. In addition, the number of previous trips did not influence the time spent on decision making. However, the higher the flow of workers, the longer the time spent on decision making. By simulating a situation with conflicting information, it was possible to verify that a hierarchical order is established by A. subterraneus, which prioritized individual information (memory). Keywords: Leafcutter ants, Trail pheromone, Memory, Synergism

Atta bisphaerica is a species of grass-cutting ants commonly found in the Cerrado biome. The Brazilian Cerrado (savanna) biome covers 2 million km representing 23% of the area of the country. It is an ancient biome with rich biodiversity, estimated at 160,000 species of plants, fungi and animals. However, little is known about their nest architecture development. This study investigated the architecture of fourteen A. bisphaerica nests from Botucatu, São Paulo, Brazil. Molds were made of the nests by filling them with cement to allow better visualization of internal structures such as chambers and tunnels. After excavation, the depth and dimensions (length, width, and height) of the chambers were measured. As expected, there was a lateral development in the nests and increase in the number of chambers over time. Results showed that in nests with an estimated age of 14 months, the average depth was 1.6 ± 0.4 m; for those with 18 months it was 2.2 ± 0.7 m and at 28 months it was 2.5 ± 0.7 m. The number of chambers varied from 4 to 7 in 28-month nests, 2 to 4 in 18-month nests, and from 2 to 3 in 14-month nests. With respect to the dimensions of the internal tunnels, there were variations in their average width, increasing with time. The fungus chambers were located beneath the largest mound of loose soil. This study contributes to a better understanding of the so far unknown nest architecture development of A. bisphaerica grass-cutting ants. Keywords: Grass-cutting ants, Nest, Social insects

Os elementos de cocriação, especialmente aqueles defendidos pelo modelo DART (PRAHALAD e RAMASWAMY, 2004) têm sido sugeridos como variáveis que impactam diretamente na percepção de confiança. Este ensaio teórico, portanto, se propõem a analisar a relação entre ambos os conceitos, fazendo um recorte para o cenário de inovação disruptiva de serviço, especialmente voltado a empresas que atuam sob o escopo da chamada economia do compartilhamento. Ao cruzar os modelos teóricos conceituais, este trabalho propõe um quadro que relaciona os elementos de cocriação trabalhados nos pontos de encontro entre os atores, e como estes permitem a comunicação necessária para interferir em variáveis como reputação e reciprocidade, ambas fundamentais para o processo de confiança. Da mesma forma, mostra como a confiança e a pré-disposição para a cooperação e a cocriação podem ser relacionadas de forma cíclica.

ABSTRACT Leaf-cutting ants live symbiotically with a fungus that they cultivate on the plant leaves that they cut. The innumerous studies on the plant selection mechanism used by leaf-cutting ants show the researchers’ interest in this issue. Many classical studies propose that plants are selected according to the fungus garden nutritional needs and the absence of potentially harmful substances. This hypothesis is corroborated by behavioral experiments using cycloheximide (fungicide) with citric pulp or forage plants greatly accepted by leaf-cutting ants. According to this hypothesis, under the action of a fungicide, the fungus emits an allomone that informs worker ants that some food is inadequate to its growth. Although some authors state that the cycloheximide “fungicide” used is specific and non toxic to ants, our findings are distinct. In our study, various concentrations of cycloheximide were administered orally to leaf-cutting worker ants in a citric pulp paste diet. After the ingestion period, the ants were isolated and offered the symbiotic fungus for 21 days and the mortality rate was evaluated. As expected, the treatment with 0.01% cycloheximide showed a low mortality rate (8.86%). At 0.1%, the mortality rate was mild (27.85%), and treatment with 1% cycloheximide resulted in moderate mortality (45.57%). In contrast, the positive control with 0.1% sulfluramid showed a high mortality rate (91.14%). Therefore, we concluded that the ingestion of high concentrations of cycloheximide results in a moderate mortality rate in leaf-cutting worker ants.

Chemical control of leaf-cutting ants is widely used, but alternative control with toxic plant extracts is promising. Substances with insecticidal potential extracted from plants have numerous ecological advantages. This study evaluated the insecticidal and/or fungicidal potential of the plants Asclepias curassavica (tropical milkweed), Rosmarinus officinalis L. (Lamiaceae) (rosemary) and Equisetum spp. (horsetail) for control of the leaf-cutting ant Atta sexdens rubropilosa Forel, 1908 (Hymenoptera: Formicidae). Forty laboratory-reared colonies of Atta sexdens rubropilosa were used. The plants were collected, dried out in a circulating air oven for 48 hours, ground, and macerated in 96o ethanol until exhaustion. After filtration, the products were evaporated under reduced pressure to obtain the ethanolic extracts. Acceptance of the reagent, topical application of the extracts, and application of baits containing 4% of the plant extracts were tested. The results showed that all plant extracts tested negatively influenced the development of the fungus garden. Baits produced with Asclepias curassavica caused the highest mortality of the colonies within 7 days. In conclusion, the ethanolic extracts of Asclepias curassavica, Rosmarinus officinalis and Equisetum spp. exhibit insecticidal (contact and ingestion) and fungicidal activity in colonies of the leaf-cutting ant Atta sexdens rubropilosa.

The success of incipient colonies of leaf-cutter ants depends on multiple factors such as temperature, humidity, soil type, the queen’s fertility and vigor, frequency of harmful microfungi, among others. Based on this observation, three factors related to Atta sexdens were characterized: (1) initial nest morphology (depth and volume); (2) queen oviposition rate; and (3) prevalence of Escovopsis (parasitic fungus) and other fungi in incipient colonies. Our observation showed a variation in chamber dimensions and volume, indicating differences in colony development rates. The oviposition rate of queens from nests of the same age showed a difference among queens. About microfungi prevalence, it was found that many are potentially deleterious. In particular, the parasite Escovopsis was present in 16.7% of the colonies. Our study shows positive correlations between queen condition and nest size/fungus garden size. These correlations collectively suggest that ecological factors such as plant availability can generate substantial variation between nests and thus shape the success of incipient colonies.

Social animals are faced with an intriguing dilemma. On the one hand, interactions between individuals are essential to exchange information and to promote cohesion, while on the other hand such interactions carry with them the risk of catching and transmitting parasites. This trade-off is particularly significant for social insects because low within-colony genetic diversity makes their colonies potentially vulnerable to parasites while frequent interactions are essential to the development of the colonial odor profile necessary for nestmate recognition. Here we investigate whether social interactions between young and old leaf-cutting ant workers show evidence of this trade-off. We find that old workers engage in more selfgrooming and mandibular scraping than young workers, both in keeping with old workers having been more exposed to parasites. In contrast, we find that young workers engaged in more allogrooming than old workers, which seems likely to have a different motivation possibly the transfer of recognition cues. Furthermore, young workers tended to engage in allogrooming with other young workers, although it was the old workers that were most active and with whom allogrooming would seem likely to optimize information or chemicals transfer. This suggests that young workers may be attempting to minimize the risk of parasite transmission during their social interactions. Although limited to behavioral data, these results hint that ant workers may be sensitive to the trade-off between the transmission of recognition cues and disease, and adjust their social interactions accordingly. Keywords: Acromyrmex, Age polyethism, Behavioral interaction, Chemicals transfer

This study investigated the stimuli that trigger digging behavior in Acromyrmex subterraneus during nest building. The hypothesis was that the presence of the fungus garden and/or brood triggers the excavation of tunnels and chambers. For the experiment, the excavation rate of individually marked workers kept in plastic cylinders filled with soil was recorded. Four treatments were applied: (1) 30 medium-sized workers, 5 g fungus garden and 30 brood items (larvae and pupae); (2) 30 medium-sized workers and 5 g fungus garden; (3) 30 medium-sized workers and 30 brood items; (4) 30 medium-sized workers without fungus and brood. After 24 h, morphological parameters of nest structure (length and width of the chambers and tunnels in cm) and the volume of excavated soil were recorded. In contrast to the expected findings, no change in morphological structure, rate of excavation by workers, or volume of excavated soil was observed between treatments, except for tunnel width, which was greater, when no brood or fungus garden was present. Thus, the results do not support the hypothesis that the fungus garden and/or brood are local stimuli for nest excavation or that they mold the internal architecture of the nest. Although this hypothesis was confirmed for Acromyrmex lundii and Atta sexdens rubropilosa, the same does not apply to A. subterraneus. The digging behavior of workers is probably the result of adaptation during nest building in different habitats. Keywords: Acromyrmex subterraneus, Digging behavior, Leaf-cutting ants, Nest building, Social insect

RESUMO Este artigo tem como objetivo fazer a revisão bibliográfica de alguns dos estudos clássicos sobre as relações raciais no Brasil. A revisão engloba o período do início dos anos 30 do século XX até os trabalhos mais recentes, que têm em comum o fato de caracterizarem a discriminação racial como fator importante para a manutenção das desigualdades raciais, reunindo argumentos que fundamentam as reflexões quanto à necessidade da adoção de políticas de ação afirmativa no Brasil, bem como os argumentos que consideram que a pobreza e a desigualdade são os fatores principais que contribuem para a marginalização do negro. Passar a limpo tais teorias e conceitos constitui contribuição significativa para dar efetividade às Diretrizes curriculares nacionais para a educação das relações étnico-raciais e para o ensino de história e cultura afro-brasileira e africana.

ABSTRACT Dynamics of the restoration of physical trails in the grass-cutting ant Atta capiguara. Leaf-cutting ants of the genus Atta build long physical trails by cutting the vegetation growing on the soil surface and removing the small objects they find across their path. Little is known on the dynamics of trail construction in these ants. How much time do they need to build a trail? To answer this question we selected six trails belonging to two different nests of A. capiguara and removed on each trail a block of soil of 20 cm × 15 cm that included a portion of the physical trail. This block was then replaced by a new block of the same size that was removed in the pasture near the trail and that was uniformly covered by the same type of vegetation as that found on the block of soil that was removed. The time required to restore the trail was then evaluated by the length of the grass blades found along the former location of the trail. The results show that ants rapidly restore the portion of the physical trail that was interrupted, which suggests that they could also do the same after their trails have been recolonized by the vegetation.

In 2009, sulfluramid, the main ingredient in toxic baits for leaf-cutting ant control, was included in Annex B of the Stockholm Convention on Persistent Organic Pollutants. This resulted in interest in the use of entomopathogenic fungi such as Beauveria bassiana and Trichoderma harzianum for leaf-cutting ant control. The efficiency of these fungi in controlling these insects and the way that ants react individually or in group to the biological risks posed by these fungi is poorly understood. For this reason, we assessed the effects of B. bassiana and T. harzianum on Atta sexdens rubropilosa larvae, pupae and workers. Moreover, we investigated whether the number of contaminated individuals within a group has an influence in controlling the spread of fungi among workers. We found that the fungus T. harzianum showed high pathogenicity against A. sexdens rubropilosa larvae and pupae, leading to faster mortality and a survival rates. On the other hand, the fungus B. bassiana was responsible for causing faster worker mortality and lower survival rates. In addition, we observed that an increase in individuals contaminated with B. bassiana or T. harzianum in the group decreases its survival rate. The results support the hypothesis that entomopathogenic fungi are efficient in controlling leaf-cutting ants when contaminated workers are allocated to groups of healthy workers.

Abstract The increased incidence of cancer and its high treatment costs have encouraged the search for new compounds to be used in adjuvant therapies for this disease. This study discloses the synthesis of (Z)-4-((1,5-dimethyl-3-oxo-2-phenyl-2,3dihydro-1H-pyrazol-4-yl) amino)-4-oxobut-2-enoic acid (IR-01) and evaluates not only the action of this compound on genetic integrity, increase in splenic phagocytosis and induction of cell death but also its effects in combination with the commercial chemotherapeutic agents doxorubicin, cisplatin and cyclophosphamide. IR-01 was designed and synthesized based on two multifunctionalyzed structural fragments: 4-aminoantipyrine, an active dipyrone metabolite, described as an antioxidant and anti-inflammatory agent; and the pharmacophore fragment 1,4-dioxo-2-butenyl, a cytotoxic agent. The results indicated that IR-01 is an effective chemoprotector because it can prevent clastogenic and/or aneugenic damage, has good potential to prevent genomic damage, can increase splenic phagocytosis and lymphocyte frequency and induces cell death. However, its use as an adjuvant in combination with chemotherapy is discouraged since IR-01 interferes in the effectiveness of the tested chemotherapeutic agents. This is a pioneer study as it demonstrates the chemopreventive effects of IR-01, which may be associated with the higher antioxidant activity of the precursor structure of 4-aminoantipyrine over the effects of the 1,4-dioxo-2-butenyl fragment.

Indigenous, African and Western cultures, along with Christianity form the cultural background of almost all countries that have gone through the process of European colonization. In all these countries the popular, social and community education has been made since its discovery and there is consensus on the quality, relevance and impact of educational practices in the constitution of the identity of their people. Each country and each people have their own historicity, motivation and strategies but all educational practices that they develop are structured from the same anthropological and cultural matrices that form their social structures, characterizing them as strategies of resistance and cultural survival, alternative to official ideology. These elements common to many peoples and countries allow to conceive to the popular, social and community education, in which a same theoretical framework is developed - the Social Pedagogy - whose most prominent theorist is undoubtedly Paulo Freire, without disregarding the contribution of many others theorists that are important for each context and specific country. Discuss about the possibility of a Social Pedagogy perspective based on Paulo Freire means to redesign the scope of Social Pedagogy itself discuss the role that it can play into the consolidation of the process of liberation of people under slavery, genocide, cultural domination and economic exploitation, as well as carry out the efforts of systematization and theorizing of different educational practices that can benefit from the same theoretical and methodological framework that can offer bases to the research, teaching and work of a large number of educators that today are not recognized as such by national education systems.

Este artigo recupera parte da pesquisa de doutoramento intitulada A eficácia sociopedagógica da pena de privação da liberdadeII, realizada no período de 1997 a 2001, junto ao Programa de Pós-Graduação em Educação da Universidade de São Paulo e defendida em 21 de agosto de 2001. A pertinência de voltar a refletir sobre o tema decorre da aprovação das Diretrizes Nacionais para a Oferta da Educação em Estabelecimentos Penais, conforme Resolução no 3, de 11 de março de 2009, do Conselho Nacional de Política Criminal e Penitenciária (CNPCP) e homologada pelo Ministério da Educação, por meio da Resolução nº 2 do Conselho Nacional de Educação (CNE) em 19 de maio de 2010. Uma consequência prática dessa normativa é a elaboração do Plano Nacional de Educação no Sistema Prisional e a obrigatoriedade de que cada estado da federação tenha o seu Plano Estadual de Educação nas Prisões, de onde emerge, implícita ou explicitamente, a ideia de um projeto político pedagógico para a educação em prisões. A pesquisa foi desenvolvida em quatro unidades de privação da liberdade, no estado de São Paulo, com uma amostra que envolve adolescentes, mulheres, homens adultos no interior do estado e homens cumprindo mais de doze anos de sentença. Trata-se de uma pesquisa longitudinal, documentada da infância à fase adulta e que diagnostica o estado em que os indivíduos entraram na prisão, as transformações que sofreram e as condições objetivas que teriam ao saírem em liberdade. As conclusões da pesquisa constituem importante subsídio para o atual debate sobre a educação em prisões no Brasil.

The isolation of microorganisms from soil impacted by xenobiotic chemicals and exposing them in the laboratory to the contaminant can provide important information about their response to the contaminants. The purpose of this study was to isolate bacteria from soil with historical application of herbicides and to evaluate their potential to degrade diuron. The isolation media contained either glucose or diuron as carbon source. A total of 400 bacteria were isolated, with 68% being Gram-positive and 32% Gram-negative. Most isolates showed potential to degrade between 10 and 30% diuron after five days of cultivation; however Stenotrophomonas acidophila TD4.7 and Bacillus cereus TD4.31 were able to degrade 87% and 68%, respectively. The degradation of diuron resulted in the formation of the metabolites DCPMU, DCPU, DCA, 3,4-CAC, 4-CA, 4-CAC and aniline. Based on these results it was proposed that Pseudomonas aeruginosa TD2.3, Stenotrophomonas acidaminiphila TD4.7, B. cereus TD4.31 and Alcaligenes faecalis TG 4.48, act on 3,4-DCA and 4-CA by alkylation and dealkylation while Micrococcus luteus and Achromobacter sp follow dehalogenation directly to aniline. Growth on aniline as sole carbon source demonstrates the capacity of strains to open the aromatic ring. In conclusion, the results show that the role of microorganisms in the degradation of xenobiotics in the environment depends on their own metabolism and also on their synergistic interactions.

Protein content of leaf-cutting ant queens before the nuptial flight and during the post-claustral phase. This study evaluated the crude protein content of queens of Atta sexdens before the nuptial flight and after the claustral phase in laboratory and field colonies. The hypothesis was that protein is used for survival of the queen and for early colony growth during the claustral phase. Additionally, the nest morphology, live biomass and adult population of field colonies were evaluated. Crude protein was determined by digestion of the organic material with sulfuric acid at high temperatures. The mean crude protein content was 123.23 ± 11.20 mg for females before the nuptial flight and 70.44 ± 12.21 mg for laboratory-reared queens after the claustral phase. The post-claustral crude protein content of field-collected queen was 55.90 ± 9.18 mg. With respect to the loss of crude protein as a function of duration of the claustral phase, laboratory-reared queens lost 52.79 mg and field-collected queens lost 67.33 mg compared to females before the nuptial flight. A positive linear correlation was observed between the weight of field-collected queens (256.4 ± 36.3 mg) and colony biomass (13.02 ± 9.12 g), but there was no correlation between biomass and nest depth (13.11 ± 3.82 cm). As expected, the present results support the hypothesis that protein is used for survival of the queen and for early colony growth, as demonstrated by the reduction in crude protein content as a function of duration of the claustral phase. To our knowledge, this is the first study to provide data of the dynamics of protein reserves in leaf-cutting ant queens during the claustral phase.

Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius). During nest excavation, leaf-cutting ant workers undergo reduction in their body reserve, particularly carbohydrates. In order to estimate the energetic cost of digging, groups of 30 workers of the leaf-cutting ant Atta sexdens were sealed in a hermetic chamber for 24, 48 and 72 hours, with and without soil for digging, and had the CO2 concentration measured using respirometric chambers as well as volume of soil excavated (g). As expected, the worker groups that carried out soil excavation expelled more carbon dioxide than the groups that did not excavate. Therefore, a worker with body mass of 9.65 ± 1.50 mg dug in average 0.85 ± 0.27 g of soil for 24 hours, consuming ca. 0.58 ± 0.23 J. In this study, we calculate that the energetic cost of excavation per worker per day in the experimental set-up was ca. 0.58 J.

O conhecimento do conteúdo energético das operárias é essencial para mensurar a disponibilidade energética, responsável pela manutenção e execução de atividades essenciais para o crescimento da colônia de formigas. Mas pouco se conhece sobre o conteúdo energético das operárias e quanto estará disponível para realizar atividades de, por exemplo, escavar do ninho. O presente estudo determinou o teor de lipídeo e o conteúdo energético das operárias de formigas cortadeiras inativas, antes e pós atividade de escavação. Por meio da determinação do teor de lipídeos, pode-se calcular o conteúdo energético das operárias em repouso (paradas) e compará-las com as que escavaram. O teor de lipídeo e conteúdo energético das operárias foram em média 9,1±0,8% e 111,31±54,71J, respectivamente, entretanto, as séries experimentais não diferiram significativamente. Adicionalmente, a taxa do fluxo catabólico, embasado na massa corporal das operárias foi de 14,76±10,11µW. Conclui-se que o recurso energético para a escavação do ninho não é proveniente de reserva de lipídeos corporal e, dessa forma, o conteúdo energético das operárias não alterou antes e pós-atividade de escavação.

Será que a vida em grupo acarreta uma maior atividade individual, e consequentemente, um maior gasto energético? Para responder a essa questão, hipotetizou-se que exista uma maior produção de CO2, quando se aumenta o tamanho do grupo de formigas operárias e, consequentemente, um maior custo energético ao indivíduo quando está em grupo. Assim, grupos de 10, 20, 30, 40 e 50 operárias foram fechados em uma câmara hermética, durante 24 horas. Posteriormente, efetuou-se a medição das concentrações de CO2 nos recipientes respirométricos. Ao contrário do esperado, a produção de CO2, e consequentemente, o gasto energético individual, não diferiram estatisticamente quando se aumentou o tamanho do grupo de operárias. Dessa forma, refuta-se a hipótese de que o tamanho do grupo conduz a um maior custo energético individual, haja vista a maior interação entre os indivíduos. O estudo com operárias de Atta sexdens rubropilosa evidenciou que o tamanho do grupo não conduz a um maior custo energético individual, sendo a produção de CO2 e, consequentemente, o gasto energético individual similar, independente do tamanho do grupo.

Anualmente, as colônias maduras de Atta spp. produzem formigas aladas, machos e fêmeas, que abandonam a colônia na qual foram produzidas para formarem novas colônias e, dessa forma, continuarem a perpetuação da espécie. A fundação de colônias de Atta spp. sempre envolve grande esforço da rainha, única responsável pelo cultivo do fungo e pelos cuidados consigo mesma e com sua prole. Nesse período de fundação ocorre o consumo de grande parte de suas reservas. O presente estudo investigou como o ambiente influencia o desenvolvimento das colônias recém-fundadas de Atta sexdens rubropilosa. Para tanto, foram comparadas colônias de campo coletadas cinco meses após a revoada e colônias mantidas em laboratório desde o voo nupcial. Foram analisados o peso e o tamanho da população (número de operárias, de larvas, de pupas e de ovos), o tamanho das operárias, o volume e peso do jardim de fungo e o esforço para a fundação dos ninhos (teor de lipídeos e peso das rainhas). Comparadas às colônias de campo, as colônias de laboratório apresentaram maiores valores no tamanho e no peso da população, no volume e no peso do jardim de fungo. As medidas das operárias, por classe de tamanho, não variaram entre as colônias de campo e de laboratório. O esforço da fundação dos ninhos foi maior nas colônias de campo, cujas rainhas apresentaram menor porcentagem de lipídeos e menor peso em relação às colônias de laboratório. Esses resultados demonstram que o ambiente exerce forte influência no desenvolvimento das colônias durante a fase de fundação, bem como sobre o status fisiológico das rainhas, sendo, portanto, a sobrevivência, o desenvolvimento e o sucesso da colônia reflexos das condições do ambiente e do esforço da rainha.

As formigas cortadeiras, importantes pragas agrícolas, anualmente realizam a fundação de novas colônias. Para o início de novas colônias, é preciso a escavação de túneis e de câmaras no solo, sendo que, para isso, as rainhas recém fecundadas gastam muita energia, no entanto a quantificação dessa energia gasta é desconhecida. Nossa hipótese é que a reserva lipídica, armazenada no corpo da rainha, seja utilizada durante a escavação do ninho. Testamos essa hipótese comparando o aumento do esforço de escavação das rainhas, as quais foram experimentalmente estimuladas a escavar uma, duas ou três vezes consecutivas, em relação ao controle, ou seja, em relação às rainhas que não escavaram. Foram quantificados a massa corporal e o teor de lipídios das rainhas. Os resultados mostraram que, ao contrário de nossas expectativas iniciais, massa e teor de lípideos não foram afetadas pelo aumento do esforço de escavação do ninho. Conclui-se que a escavação pelas rainhas não afetou os percentuais de lipídios em seu corpo, consequentemente, o conteúdo de energia. Provavelmente, os recursos energéticos para a escavação não se originam de fontes lipídicas, mas de outros, provavelmente carboidratos.