958 resultados para DARK CLUMP
Resumo:
Fungi require special substrates for their isolation, vegetative growth and sporulation. In experiments conducted in the laboratory, the influence of substrates, light, filter paper and pH on the sporulation of Cercospora sojina conidia, the causal agent of soybean frogeye leaf spot, was assessed. The media potato sucrose agar, V-8 agar, tomato extract agar, soybean leaf extract agar, soybean seed extract agar, soybean meal agar, soybean flour agar and wheat flour agar were tested, added on the surface, with and without filter paper and under two light regimes, with 12 h light at 25°± 2°C and in the dark. A triple factorial 8x2x2 (substrates x light/dark x with/without filter paper) design with four replicates was used. V-8 agar medium was employed and the pH was adjusted with HCl 0.1N or NaOH 0.1N before autoclaving to the values: 3, 4, 5, 6, 7 and 8, and the pH of V-8 agar medium is 6.7. The evaluation was done on the seventh day of incubation. Data underwent regression analysis. Sporulation was maximized on the agar media V-8, seed extract, oat flour, tomato extract, and potato sucrose in the presence of filter paper and 12h light. On V-8 medium, maximal sporulation was obtained with pH 6.7.
Resumo:
In vitro experiments were conducted to assess the effects of substrate, temperature and time of exposure to temperature and photoperiod on P. pachyrhizi uredospore germination and germ tube growth. The following substrates were tested: water-agar and soybean leaf extract-agar at different leaf concentrations (0.5, 1.0, 2.0 and 4.0 g of leaves and 15g agar/L water), temperatures (10, 15, 20, 25, 30, and 35oC) and times of exposure (1, 2, 3, 4, 5, 6, 7, and 8 hours) to temperature and 12 different photoperiods. The highest germination and germ tube length was found for the soybean leaf extract agar. Maximum P. pachyrhizi uredospore germination was obtained at 21.8 and 22.3°C, and maximum germ tube growth at 21.4 and 22.1°C. The maximum uredospore germination was found at 6.4 hours exposure, while the maximum germ tube length was obtained at 7.7 h exposure. Regarding photoperiod, the maximum spore germination and the maximum uredospore germ tube length were found in the dark. Neither spore germination nor uredospore germ tube growth was completely inhibited by the exposure to continuous light.
Resumo:
Kirjallisuusarvostelu
Resumo:
Paper presented at the 40th Annual Conference of LIBER (Ligue des Bibliothèques Européennes de Recherche - Association of European Research Libraries) on July 1st, 2011; with the slides used at the presentation.
Resumo:
Photosynthesis, the process in which carbon dioxide is converted into sugars using the energy of sunlight, is vital for heterotrophic life on Earth. In plants, photosynthesis takes place in specific organelles called chloroplasts. During chloroplast biogenesis, light is a prerequisite for the development of functional photosynthetic structures. In addition to photosynthesis, a number of other metabolic processes such as nitrogen assimilation, the biosynthesis of fatty acids, amino acids, vitamins, and hormones are localized to plant chloroplasts. The biosynthetic pathways in chloroplasts are tightly regulated, and especially the reduction/oxidation (redox) signals play important roles in controlling many developmental and metabolic processes in chloroplasts. Thioredoxins are universal regulatory proteins that mediate redox signals in chloroplasts. They are able to modify the structure and function of their target proteins by reduction of disulfide bonds. Oxidized thioredoxins are restored via the action of thioredoxin reductases. Two thioredoxin reductase systems exist in plant chloroplasts, the NADPHdependent thioredoxin reductase C (NTRC) and ferredoxin-thioredoxin reductase (FTR). The ferredoxin-thioredoxin system that is linked to photosynthetic light reactions is involved in light-activation of chloroplast proteins. NADPH can be produced via both the photosynthetic electron transfer reactions in light, and in darkness via the pentose phosphate pathway. These different pathways of NADPH production enable the regulation of diverse metabolic pathways in chloroplasts by the NADPH-dependent thioredoxin system. In this thesis, the role of NADPH-dependent thioredoxin system in the redox-control of chloroplast development and metabolism was studied by characterization of Arabidopsis thaliana T-DNA insertion lines of NTRC gene (ntrc) and by identification of chloroplast proteins regulated by NTRC. The ntrc plants showed the strongest visible phenotypes when grown under short 8-h photoperiod. This indicates that i) chloroplast NADPH-dependent thioredoxin system is non-redundant to ferredoxinthioredoxin system and that ii) NTRC particularly controls the chloroplast processes that are easily imbalanced in daily light/dark rhythms with short day and long night. I identified four processes and the redox-regulated proteins therein that are potentially regulated by NTRC; i) chloroplast development, ii) starch biosynthesis, iii) aromatic amino acid biosynthesis and iv) detoxification of H2O2. Such regulation can be achieved directly by modulating the redox state of intramolecular or intermolecular disulfide bridges of enzymes, or by protecting enzymes from oxidation in conjunction with 2-cysteine peroxiredoxins. This thesis work also demonstrated that the enzymatic antioxidant systems in chloroplasts, ascorbate peroxidases, superoxide dismutase and NTRC-dependent 2-cysteine peroxiredoxins are tightly linked up to prevent the detrimental accumulation of reactive oxygen species in plants.
Resumo:
ABSTRACT The species of the genus Byrsonima Rich. ex Kunth are of great medicinal and economic importance, but they are still poorly studied with respect to their propagules. This study describes, illustrates and comparse morphological aspects of the pyrenes of Byrsonima crassifolia (L.) Kunth, Byrsonima verbascifolia (L.) DC. and Byrsonima coccolobifolia Kunth occurring in areas of savannah of Boa Vista, Roraima. The pyrenes are globoid, obovoid to ovoid, with endocarp dark brown in color, with a corrugated and reticulate surface and corneous consistency. They possess distinctly septate locules with or without seeds, the outer wall of which are dark brown in color with corneous consistency and thin black inner walls also with corneous consistency. The number of locules and seeds per pyrene among the species varies. The seeds are exalbuminous, globoid, obovoid to ovoid, with a thin, smooth integument and are light-brown in color. They have radicular lobes and hypostasis. The embryo is continuous and axial with cylindrical spirally rolled cotyledons. The diameter of pyrenes of Byrsonima crassifolia is greater than in the other two species. The pyrenes of B. coccolobifolia are longer and heavier, while those of B. verbascifolia are lighter and the seeds have greater lengths, widths and thickness compared to the other two species studied. The three species have similar morphologies, differing in the size and weight of pyrenes and seeds.
Resumo:
Cyanobacteria are a diverse group of oxygenic photosynthetic bacteria that inhabit in a wide range of environments. They are versatile and multifaceted organisms with great possibilities for different biotechnological applications. For example, cyanobacteria produce molecular hydrogen (H2), which is one of the most important alternatives for clean and sustainable energy. Apart from being beneficial, cyanobacteria also possess harmful characteristics and may become a source of threat to human health and other living organisms, as they are able to form surface blooms that are producing a variety of toxic or bioactive compounds. The University of Helsinki Culture Collection (UHCC) maintains around 1,000 cyanobacterial strains representing a large number of genera and species isolated from the Baltic Sea and Finnish lakes. The culture collection covers different life forms such as unicellular and filamentous, N2-fixing and non-N2-fixing strains, and planktonic and benthic cyanobacteria. In this thesis, the UHCC has been screened to identify potential strains for sustainable biohydrogen production and also for strains that produce compounds modifying the bioenergetic pathways of other cyanobacteria or terrestrial plants. Among the 400 cyanobacterial strains screened so far, ten were identified as high H2-producing strains. The enzyme systems involved in H2 metabolism of cyanobacteria were analyzed using the Southern hybridization approach. This revealed the presence of the enzyme nitrogenase in all strains tested, while none of them are likely to have contained alternative nitrogenases. All the strains tested, except for two Calothrix strains, XSPORK 36C and XSPORK 11A, were suggested to contain both uptake and bidirectional hydrogenases. Moreover, 55 methanol extracts of various cyanobacterial strains were screened to identify potent bioactive compounds affecting the photosynthetic apparatus of the model cyanobacterium, Synechocystis PCC 6803. The extract from Nostoc XPORK 14A was the only one that modified the photosynthetic machinery and dark respiration. The compound responsible for this effect was identified, purified, and named M22. M22 demonstrated a dual-action mechanism: production of reactive oxygen species (ROS) under illumination and an unknown mechanism that also prevailed in the dark. During summer, the Baltic Sea is occupied by toxic blooms of Nodularia spumigena (hereafter referred to as N. spumigena), which produces a hepatotoxin called nodularin. Long-term exposure of the terrestrial plant spinach to nodularin was studied. Such treatment resulted in inhibition of growth and chlorosis of the leaves. Moreover, the activity and amount of mitochondrial electron transfer complexes increased in the leaves exposed to nodularin-containing extract, indicating upregulation of respiratory reactions, whereas no marked changes were detected in the structure or function of the photosynthetic machinery. Nodularin-exposed plants suffered from oxidative stress, evidenced by oxidative modifications of various proteins. Plants initiated strategies to combat the stress by increasing the levels of alpha-tocopherol, mitochondrial alternative oxidase (AOX), and mitochondrial ascorbate peroxidase (mAPX).
Resumo:
Banana is the most consumed fruit in the world and Brazil is the second largest producer. Despite its global position, Brazil has an average of 40% losses during the post-harvest period. So, this experiment aimed at evaluating the efficiency of post-harvest treatments to improve the storage of banana cultivars cv. 'Prata', 'Maçã' and 'Nanica'. The fruits were acquired at CEASA with green peel, and were submitted to six different treatments: T- immersion in drinking water for 3 minutes (control), H3 - hot water (50 °C for 3 minutes), H8 - hot water (50 °C for 8 minutes), HP - immersion in hypochlorite 0.2% for 3 minutes, OS - immersion in soybean oil 10% for 3 minutes, and OM - immersion in mineral oil 10% for 3 minutes. The fruits were stored at room temperature at about 21 °C for 14 days and evaluated in three periods (1, 7 and 14 days) comparing peel color, flesh/peel ratio, titratable acidity (TA), soluble solids (SS), SS/TA ratio, and pH. The fruits of cv. 'Prata' and 'Maçã' submitted to the treatments H3, H8 and HP ripened at the same time as the control for peel color, which showed increased soluble solids, flesh/peel ratio, acidity and a decrease in pH. On the other hand, the cv. 'Nanica' did not respond significantly different when compared to the applied treatments and the control. The fruits treated with OM and OS were kept green for a longer time for the cultivars 'Prata' and 'Nanica', but there were some changes on peel color due dark spots in 'Prata' banana and a softening aspect in 'Nanica', indicating some level of toxicity of these treatments. Fruits of the 'Maçã' cultivar continued green with the application of mineral oil, without toxicity symptoms. In conclusion, the treatments applied did not show any advantage for storage of these fruits.
Resumo:
The potassium ion, present in great amount in the vinasse because it is a monovalent cation, has the characteristic of promoting the dispersion of clay particles, in the same way as the sodium, causing a reduction in the pore space of the soil and, in its turn, reducing its permeability. To evaluate this effect of reduction by application of vinasse to the soil, an experiment was conducted for three different soils, with the objective of evaluating the effect of the application of different doses of vinasse on hydraulic conductivity of saturated soil and verifying its possible chemical changes of these soils. For that, it was used PVC columns (in a scheme of constant head permeameter to obtain the values of hydraulic conductivity of saturated soil), filled with three soils - Dark Red Latosol (DRL), Purple Latosol (PL) and Eutrophic Red Nitossol (ERN) - , in which were applied four doses of vinasse (0, 150, 300 and 450m³ ha-1), distributed in a completely randomized design with a 3x4 factorial scheme with three replications. The results evidenced that only the Dark Red Latosol (DRL) showed a reduction in the values of hydraulic conductivity of saturated soil, and in front of the application of vinasse, up to 300m³ ha-1, it was observed an increase in the concentrations of potassium, calcium and cation exchange capacity (CEC) ions.
Resumo:
Kirjallisuusarvostelu
Resumo:
O sistema de ventilação e de resfriamento utilizado em instalações para frangos de corte desempenha um papel importante no controle ambiental, possibilitando que a ave expresse seu potencial máximo de produção. Nesse sentido, o objetivo deste trabalho foi avaliar, por meio da geoestatística, a influência do sistema de ventilação e das diferentes tipologias construtivas em relação ao ambiente térmico e aéreo em aviários de frangos de corte na fase final de criação. Os aviários avaliados com sistema de ventilação artificial de pressão negativa, por meio de exaustores, foram: Blue House com nebulizadores na entrada de ar e vedação de cortinas; Dark House com painel evaporativo (tijolo cerâmico) e vedação de cortinas e Solid Wall com painel evaporativo (celulose) e vedação de alvenaria. Os atributos avaliados foram: temperatura, umidade relativa, velocidade do ar, concentração de dióxido de carbono e amônia, durante o período de verão às 14h, em 52 pontos equidistantes, no interior do aviário. Os dados foram avaliados pela análise estatística e geoestatística. A análise geoestatística apresentou-se como ferramenta eficiente para a avaliação da distribuição das condições ambientais nos aviários, e a presença ou não do painel evaporativo influenciou na condição padrão de funcionamento do sistema de ventilação.
Resumo:
ABSTRACT Broiler poultry is highly dependent on artificial lightening. Power consumption costs of artificial lighting systems is the second largest expense related to broiler industry, second only to feed expenses. Therefore, the current study focused to analyze technical and economic feasibility of replacing incandescent lamps already used in aviaries with other lamp types. Costs related to power consumption, implementation and maintenance of the lighting systems were evaluated with the aid of financial mathematics using net present value, return over investment and payback. Systems composed of six lamp types were analyzed in two different configurations to meet the minimum illuminance of 5 and 20 lux and for use in conventional sheds and dark house. The lamps tested were incandescent (LI) of 100 W, compact fluorescent (CFL) of 34 W, mixed (ML) 160 W sodium vapor (SVL) of 70 W, tubular fluorescent T8 (TFL T8) of 40 W and tubular fluorescent T5 (TFL T5) of 28 W. For the systems tested, it was found that the tubular fluorescent lamps T8 and T5 showed the best results of technical and economic feasibility.
Resumo:
Tutkimuksen tavoitteena oli kartoittaa alueellisen jäteyhtiön Kymenlaakson Jäte Oy:n mahdollisuuksia rakeistaa ja termisesti kuivata mekaanisesti kuivattua mädätysjäännöstä sekä mahdollisuuksia toimittaa termisesti kuivattua materiaalia energiahyötykäyttöön. Tutkimuksessa selvitettiin myös kokemuksia lattialämmityksen käyttämisestä mädätysjäännöksen kuivaukseen. Tutkimuksessa perehdyttiin erilaisiin rakeistus- ja kuivausmenetelmiin sekä termisen kuivurin valintaan vaikuttaviin asioihin. Kuvaukset perustuvat kirjallisuudesta ja internetistä saatuihin tietoihin. Tekniikkakuvausten pohjalta lähdettiin kyselemään tarjouksia termisiä kuivauslaitteistoja myyviltä yrityksiltä. Tarjoukset pyydettiin kuiva-ainepitoisuuden muutokselle 30 %:sta 90 %:iin ja oletettiin, että kuivaukseen on käytettävissä lämpöä viideltä kaatopaikkakaasua käyttävältä mikroturbiinilta. Tutkimuksen aikana saatiin tarjous kuudelta yritykseltä. Saadut tarjoukset esiteltiin tiivistetysti raportissa ja kokonaisuudessaan ne sisällytettiin Kymenlaakson Jäte Oy:n laajempaan raporttiin, joka ei ole julkinen. Yritykset antoivat hyvin erilaisia tietoja siitä, mitä tarjoukseen sisältyy, joten tarjoukset eivät olleet suoraan vertailukelpoisia. Tarjouksista myös havaittiin, että jos Mäkikylän biokaasulaitokselta vastaanotettaisiin enimmäismäärä (19 500 t/a) mädätysjäännöstä, mikroturbiineilta saatava lämpömäärä ei riittäisi kuivaamaan kaikkea mädätysjäännöstä 90 % kuiva-ainepitoisuuteen. Tutkimuksen aikana huomattiin myös, että sitovan tarjouksen saamiseksi mädätysjäännös tulee toimittaa testattavaksi, jolloin saadaan vahvistus kuivausmenetelmän soveltuvuudesta kyseiselle materiaalille. Tutkimuksessa selvitettiin myös, minkälaisia kokemuksia löytyy lattialämmityksen käyttämisestä kuivaukseen niin Suomesta kuin maailmalta ja voiko menetelmää käyttää mädätysjäännöksen kuivaukseen. Kyseistä menetelmää on käytetty tehostamaan aurinkokuivausta, joten tutkimuksen aikana perehdyttiin erityisesti aurinkokuivaukseen liittyviin tieteellisiin artikkeleihin. Lattialämmityksen käytöstä löytyi niin heikkouksia kuin vahvuuksia. Suomessa aurinkokuivauksen ja lattialämmityksen yhdistelmä ei ole kuitenkaan päätynyt laajaan käyttöön ja syynä voidaan nähdä muun muassa kylmät ja pimeät vuodenajat sekä suuri pinta-alan tarve. Tutkimusraportissa selvitettiin lisäksi polttolaitosten edustajien kiinnostusta ja rajoituksia ottaa vastaan termisesti kuivattua mädätysjäännöstä. Tutkimuksen aikana otettiin yhteyttä alle 100 km etäisyydellä Kymenlaakson Jäte Oy:stä sijaitsevien jätteenpolttoluvan omaavien yritysten edustajiin. Saatuja vastauksia käsiteltiin tiivistetysti raportissa ja vastaukset sisällytettiin kokonaisuudessaan Kymenlaakson Jäte Oy:n laajempaan raporttiin, joka ei ole julkinen. Puhelinhaastattelujen pohjalta nähtiin, että yrityksillä on kiinnostusta materiaalia kohtaan, mutta samalla vastauksiin vaikuttavat mädätysjäännöksen analyysitulokset. Poltto-ominaisuuksiin liittyvät analyysit tullaan toteuttamaan vuoden 2012 aikana. Laitoksilla oli myös vaihtelevia rajoituksia materiaalia kohtaan, mutta analyysituloksista riippuen materiaalia voidaan hyödyntää energiana tuhansia tai jopa kymmeniä tuhansia tonneja vuodessa alle 100 km etäisyydellä Kymenlaakson Jäte Oy:stä.
Resumo:
Two outbreaks of zigomycosis with rhinofacial and two other with rhinopharyngeal lesions involving fungi with filamentous coaenocytic hyphae characteristic of entomoph-thoramycetous fungi are reported in the state of Paraíba, northeastern Brazil. One outbreak of rhinofacial zygomycosis occurred during the rainy season affecting 5 sheep. Another outbreak of the clinical form affected one out of 40 sheep during the dry season. Common clinical signs of the rhinofacial infection were bilateral serosanguineous nasal discharge with swelling of nostrils, upper lip, and the skin of the face. At necropsy the nasal mucosa showed dark brownish ulcerated areas which extended from the mucocutaneous region to 10cm inside the nasal vestibule. The mucosa of the hard palate was also ulcerated. The cutting surface of nostrils and palate showed a brownish or red spongeous tissue of friable consistency. One outbreak of rhinopharyngitis took place on an irrigated coconut farm; 7 out of 60 adult sheep were affected. Another outbreak affected a sheep in a flock of 80 during the dry season. Clinical signs as noisy respiration and dyspnoea due to mechanical blockage of the nasal cavities, swelling of the nostrils, and serosanguineous nasal discharge were observed. Six out of 8 sheep in this group showed exophthalmia, keratitis and unilateral corneal ulceration of the eye. The sheep either died of their infection or were euthanized after a clinical course of 7-30 days. At necropsy there was a dense yellow exudate in the nasopharyngeal area affecting the ethmoidal region, turbinate bones, paranasal sinuses, hard and soft palates, orbital cavity, pharynges, regional muscles and lymph nodes. Histopathologically both forms of the disease showed multifocal granulomas with an eosinophilic necrotic reaction (Splendore-Hoeppli phenomenon) containing ribbon-type coenocytic hyphae with 7-30mum in diameter similar to hyphae of zygomycetous fungi, possibly Conidiobolus spp. Outbreaks of both forms of mycotic rhinitis are common in northeastern Brazil and in other regions of the country.
Resumo:
Two eimerid coccidia are reported in a capybara (Hydrochoerus hydrochaeris) population kept in captivity in the south of Bahia, northeastern Brazil (14º 47' 57.89"S and 39º 10' 10.58" W). Oocysts of Eimeria ichiloensis are subspheroidal to ellipsoidal, 26.2 x 21.7mm with bi-layered wall, the outer yellow and sculptured and the inner, dark and smooth. Residuum is absent, but usually 2-3 polar granules are present. Sporocysts are ovoid, 12.0 x 7.6mm. Stieda body and sporocyst residuum are present. Oocysts of Eimeria trinidadensis are subspheroidal to ellipsoidal, 22.2 x 19.6mm with bi-layered wall, the outer yellow and smooth, and the inner dark and smooth. Residuum is absent, but one polar granule is present. Sporocysts are ovoid, 11.0 x 6.9mm. Stieda body and sporocyst residuum are present. Based on these descriptions and previous ones it can be concluded that these coccidea species are widely dispersed in capybaras in South America.