Systematic uncertainties from halo asphericity in dark matter searches

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Complex scalar dark matter in a B-L model

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The community-level effect of light on germination timing in relation to seed mass: a source of regeneration niche differentiation

Within a community, species may germinate at different times so as to mitigate competition and to take advantage of different aspects of the seasonal environment (temporal niche differentiation). We illustrated a hypothesis of the combined effects of abiotic and biotic competitive factors on germination timing and the subsequent upscale effects on community assembly. We estimated the germination timing (GT) for 476 angiosperm species of the eastern Tibetan Plateau grasslands under two light treatments in the field: high (i.e. natural) light and low light. We also measured the shift in germination timing (SGT) across treatments for all species. Furthermore, we used phylogenetic comparative methods to test if GT and SGT were associated with seed mass, an important factor in competitive interactions. We found a significant positive correlation between GT and seed mass in both light treatments. Additionally, small seeds (early germinating seeds) tended to germinate later and large seeds (late germinating seeds) tended to germinate earlier under low light vs high light conditions. Low light availability can reduce temporal niche differentiation by increasing the overlap in germination time between small and large seeds. In turn, reduced temporal niche differentiation may increase competition in the process of community assembly.

GERMINATION OF EUCALYPTUS SEEDS UNDER WATER AND SALT STRESS

The knowledge of the physiology of Eucalyptus spp. germination may contribute significantly to the development of management and choice of suitability of the deployment areas. The aim was to evaluate the effects of water and salt stress on seed germination of Eucalyptus camaldulensis, E. citriodora, E. grandis, E. robusta and E. urophylla. The seeding was done with four replicates of 0.05 g of seeds in paper moistened with solutions at potentials of 0.0, -0.2, -0.4, and -0.8 MPa, induced with polyethylene glycol (PEG 6000) and NaCl. The germination test was in 25 degrees C in the presence of light. Were evaluated the first test score seven days after sowing, and weekly germination (normal seedlings) until 28 days. Were also calculated the germination speed index. Water stress causes a greater reduction in the rate of germination and accumulated germination of E. camaldulensis and E. citriodora seeds than salt stress, and the seeds of E. robusta are more adapted to germinate under salt stress moderate, between -0.2 and -0.4 MPa. Regardless of the substance used to induce stress, the threshold for germination was -0.8 MPa. The E. camaldulensis is the most sensitive specie to water stress and E. urophylla most sensitive to salt stress.

Avaliação dos efeitos citotóxicos, genotóxicos e mutagênicos do fipronil, após fotodegradação, utilizando Allium cepa como organismo teste

Compounds released into the environment can induce genetic alterations in living organisms. A group of chemicals that shows proven toxicity is the pesticides, and the insecticides are the most harmful. The insecticides of the family phenylpyrazole have wide application both in agriculture and in homes. Fipronil, an insecticide of this chemical group, is widely used in various cultures and in homes, mainly for fighting fleas and ticks on dogs and cats. The use of fipronil may represent a risk to man and the environmental health, since this pesticide can potentially induce cell death, regardless of cell type. Fipronil, when in contact with the environment, can undergo various degradation processes, including photodegradation. The toxic effect of one of its metabolites derived from photodegradation, sulfone-fipronil, is approximately 20 fold as great as fipronil itself. The A. cepa test system was used to evaluate cytotoxic, genotoxicity and mutagenic effects of fipronil before and after phptodegradation. Seeds of Allium cepa were subjected to solutions of fipronil, pre-exposed or not exposed to degradation by sunlight. The germination tests were conducted both under the effect of light and in the dark. We evaluated the cumulative potential of this insecticide using 48 and 72-hours recovery tests. The results showed that when fipronil was previously exposed to the sun, it presented a greater genotoxic and mutagenic potential, showing that the metabolites formed by photodegradation can show more harmfull effects

A Confluência de Gêneros em Dark Water, de Walter Salles Jr.

Dark Water is the title of the translation of a short story, ―Floating Water‖, from the book Honogurai mizu no soko kara by Koji Suzuki, originally published in Japan, that the Japanese director Hideo Nakata adapted for the cinema and that was remade by the Brazilian director Walter Salles Jr. The objective of this study is to analyse Walter Salles’ film to demonstrate how it resolved the problems of transcreation, whilst at the same time it fulfilled commercial and artistic functions and incorporated the traces of its aesthetic trajectory. In this case, attention is drawn to the types of relationship between literature and cinema, to the metalinguistic function as a generator of poetics and of an interesting dialogue between genres.

Close Enough to One Another and Far Apart as Well´: The Intersection of Literature and History in Seamus Deane´s Reading in the Dark

This article analyses the intersection of narrative and history in Seamus Deane’s Reading in the Dark (1996). It uses the Benjaminian notions of memory, narration and experience to investigate how this novel creates a self through a language characterized by the absence of what it refers to. The analysis will eventually demonstrate that the tension between recollection and obliteration makes Literature and History converge as products of a narrative act.

Short-term effect of alginate-biochar microbeads in corn germination

Biochar is the solid by-product of biomass pyrolysis. It is a promising soil conditioner and can be a material with high aggregate economic value, since its performance can improve plant’s nutrient utilization and reduce the usage of conventional fertilizers. Biochar can be used in the formulation of new types of fertilizers as polymeric microbeads. These microbeads can be enriched with biochar and nutrients in its matrix to form fertilizers of slow release of nutrients. Thus, as a promising agricultural material, it is important to assess the environmental hazards caused by the implementation of these microbeads. In this context, seeds were sown in a soil-less Petri dish with microbeads produced with biochar from sugarcane enriched with or without phosphate. The seeds germination and its vitality were evaluated by the first germination count (FGC) and the germination speed index (GSI). The short-term effects showed that the microbeads, in general, assessed by the means of FGC, GSI and mass gain showed the best performance, suggesting that the environment created by these materials provided the best chemical and physical interaction with the embryonic axes.

Bioconversion of Cellulose to Hydrogen by dark fermentation

Hydrogen is known as a clean energy resource. The biological production of hydrogen has been attracting attention as an environmentally friendly processs that does not consume fossil fuels. Cellulosic plant and waste materials are potential resources for fermentative hydrogen production. Cellulose is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Enzymatic hydrolysis of cellulose requires the presence of cellulase. The present study aimed to investigate the efficiency of acid pretreatment on ruminal fluid in order to enrich H2 producing bacteria consortia to enhance biohydrogen rate and substrate removal efficiency. In this study, fermentative hydrogen producers were enriched on cellulose (2g/L) in a modificated Del Nery medium (DNM) at 37ºC and initial pH 7.0 using rumen fluid (10% v/v) as inoculum. To increase the hydrogen production it was added cellulose (10mL) to the medium. The gas products (mainly H2 and CO2) was analyzed by gas chromatography (Shimadzu GC 2010) using a thermal conductivity detector. The volatile fatty acids and ethanol were also detected by GC using a flame ionization detector. Cellulose degradation was quantified by using the phenolsulfuric acid method. Analysis showed that the biogas produced from the anaerobic fermentation contained only hydrogen and carbon dioxide, without detectable methane after acid pretreatment test. On DNM the hydrogen production started with 4 h (5,3 x 105 mmol H2/L) of incubation, and the maximum H2 concentration was observed with 34 h (7,1 x 106 mmol H2/L) of incubation. During the process, it was observed a predominance of acetic acid and butyric acid as well as a low production of acetone, ethanol and nbutanol in all experimental phases. Butyrate accounted for more than 77% of total. As a result of the accumulation of volatile fatty acids (VFAs), the pH value in anaerobic digestion system was reduced to 4,0. On microscopy analyses there were observed rods with endospores. The batch anaerobic fermentation assays performed on anaerobic mixed inoculum from rumen fluid demonstrated the feasibility of H2 generation utilizing cellulose as substrate. Based on the results, it can be concluded that the acid treatment was efficient to inhibit the methanogenic archaea cells present in rumen fluid. The rumen fluid cells present a potential route in converting renewable biomass such as cellulose into hydrogen energy.

Phytotoxicity of Tagetes erecta L. and Tagetes patula L. on plant germination and growth

This study evaluated the phytotoxic potential and antioxidant activity of Tagetes patula and Tagetes erecta, and total phenols and flavonoids of the extracts were quantified. Laboratory bioassays for both pre- and post-emergence were performed in Lactuca sativa L. seeds and in the Allium cepa seeds test. The antioxidant activity was evaluated by DPPH radical scavenging and reducing power of iron, besides total phenols and flavonoids quantification in the extracts. Thus, was observed a reduction in the mitotic index when in compared with the negative control. Was observed also a reduction the germination and development of tested seedlings and was verified a considerable antioxidant potential and presence of flavonoids and phenolic compounds in the extracts. According to these results, it is possible to conclude that T. erecta and T. patula have phytotoxic compounds that may enhance and expand their use in the management of organic agriculture, mainly in vegetables.

Priming and temperature limits for germination of dispersal units of Urochloa brizantha (Stapf) Webster cv. basilisk

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigation on the s of guava (Psidium guajava L.) infusions on germination, root tips and meristematic cells of Latuca sativa

Guava (Psidium guajava L.) is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa (purple) - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L-1) prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic was significant. Therefore, guava should not be used indiscriminately in popular medicine.

Effects of hormonal priming on seed germination of pigeon pea under cadmium stress

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A intersecção entre literatura, memória e história em Reading in the dark, de Seamus Deane

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Evidence for dark matter in the inner Milky Way

The ubiquitous presence of dark matter in the Universe is today a central tenet in modern cosmology and astrophysics(1). Throughout the Universe, the evidence for dark matter is compelling in dwarfs, spiral galaxies, galaxy clusters as well as at cosmological scales. However, it has been historically difficult to pin down the dark matter contribution to the total mass density in the Milky Way, particularly in the innermost regions of the Galaxy and in the solar neighbourhood(2). Here we present an up-to-date compilation of Milky Way rotation curve measurements(3-13), and compare it with state-of-the-art baryonic mass distribution models(14-26). We show that current data strongly disfavour baryons as the sole contribution to the Galactic mass budget, even inside the solar circle. Our findings demonstrate the existence of dark matter in the inner Galaxy without making any assumptions about its distribution. We anticipate that this result will compel new model-independent constraints on the dark matter local density and profile, thus reducing uncertainties on direct and indirect dark matter searches, and will help reveal the structure and evolution of the Galaxy.