Degrada����o de Ocratoxina a: estudo de processo e toxicidade

A ocratoxina A (OTA), micotoxina encontrada em diferentes n��veis e em diversas matrizes, apresenta efeitos carcinog��nicos, nefrot��xicos e teratog��nicos. O desenvolvimento de m��todos capazes de diminuir esta contamina����o a n��veis permitidos pela legisla����o �� incentivado e os processos biol��gicos utilizados envolvem o uso de enzimas e/ou microrganismos para degrada����o da OTA e s��o preferenciais pela especificidade, bem como pelas condi����es brandas para a detoxifica����o. O objetivo do trabalho foi estudar a a����o de carboxipeptidase A nos n��veis e na toxicidade de OTA, visando aplicar a t��cnica para detoxificar farinhas de trigo. Primeiramente foi estimado o risco de exposi����o �� ocratoxina A pelo consumo de farinhas de trigo. Para isso foram estabelecidas condi����es de determina����o de OTA em farinhas de trigo, empregando t��cnicas de estat��stica multivariada para definir os principais interferentes na extra����o de OTA pelo m��todo de QuEChERS e detec����o em CLAE-FL. O m��todo validado permitiu a avalia����o da ocorr��ncia natural em 20 amostras de farinha de trigo, estando estas contaminadas na faixa de 0,22 a 0,85 ��g.kg-1 , apresentando um valor de ingest��o di��ria de 0,08 ngOTA.dia-1 .kgmassacorp��rea -1 e uma disponibilidade de 94,4%. Em seguida foi realizada a padroniza����o da extra����o de carboxipeptidase A em biomassa de Rhizopus oryzae que consistiu em agita����o ultrass��nica durante 30 minutos numa potencia fixa de 150 W e 40 kHz e a triagem de agentes biol��gicos para degrada����o de OTA. Para o estudo da degrada����o in vitro de OTA, m��todo de extra����o e detec����o de OTA e OT�� em CLAEFL foi validado e o processo de degrada����o foi realizado com Rhizopus oryzae e Trichoderma reesei, obtendo-se uma redu����o m��xima de 63,5% e 57,7%, respectivamente. A degrada����o apresentou uma correla����o alta (R>0,9) e significativa (p<0,05) com a produ����o de Ot��, indicando que ocorreu a produ����o de enzimas capazes de hidrolisar a micotoxina, por exemplo, a carboxipeptidase A. O estudo da toxicidade de OTA e seu metab��lito OT�� foi realizado em neutr��filos humanos, onde foi observado a aus��ncia de efeito t��xico de OT��. Tamb��m foi determinado o mecanismo de toxicidade de OTA pelo aumento de Ca2+ intracelular pela libera����o a partir das reservas internas. Esta libera����o, subsequentemente, provoca uma cascata de eventos, nomeadamente: a produ����o de esp��cies reativas, deple����o de ATP, perda de ����m, levando �� morte por necrose. Para reduzir o risco de exposi����o �� micotoxina pela ingest��o de mat��ria prima contaminada, carboxipeptidase A extra��da de diferentes fontes foi aplicada na hidr��lise de OTA em farinha de trigo para posterior determina����o do conte��do residual de OTA e OT��, empregando m��todo validado. O estudo mostrou uma redu����o de OTA entre 16,8 e 78,5% e produ����o de OT�� entre 2 a 8,2 ng.g-1 . As carboxipeptidases mais promissoras para degrada����o foram as provenientes de Rhizopus e Trichoderma e a carboxipeptidase comercial. Ficou demonstrado que se pode recomendar a aplica����o de enzimas proteol��ticas, tipo carboxipeptidase, para reduzir o risco de exposi����o �� micotoxina quando utilizada mat��ria prima contaminada, por exemplo, farinha de trigo para diferentes processos. A transforma����o de OTA para OT�� e seus efeitos na redu����o da toxicidade da micotoxina corroboram com esta afirma����o.

O desejo no feminino

Disserta����o de Mestrado apresentada no ISPA ��� Instituto Universit��rio para obten����o de grau de Mestre na especialidade de Psicologia Cl��nica

E-handel- Konkurrent eller komplement f��r mikrof��retag? : En studie om lokala mikrof��retag

I dagens samh��lle har det skett en strukturomvandling p�� marknaden g��llande detaljhandeln.Strukturomvandlingen har inneburit utveckling av bland annat omnikanaler och e-handelvilket har f��r��ndrat f��retagens aff��rsmodellsval f��r att kunna ��verleva p�� marknaden. Ehandelnhar i m��nga ��r setts som en konkurrent f��r mikrof��retag, men det b��rjar ��ven blim��jligt f��r mikrof��retag att inf��ra ett integrerat system som inneb��r att den fysiska butikensamverkar med e-handeln. Resultatet av de ��kade m��jligheterna f��r mikrof��retag ��r att de kanv��lja mellan tre olika aff��rsmodellsval g��llande sin marknadsplats och tillg��nglighet avf��retaget och sedan utifr��n omnikanaler kan f��retagen v��lja hur de vill n�� ut tillkonsumenterna.I denna studie vill vi f�� en ��kad f��rst��else f��r hur lokala mikrof��retag arbetar med att beh��llasin marknadsplats i den ��kade konkurrensen som blir i och med e-handelns tillv��xt. F��r attkunna unders��ka mikrof��retagen har vi till��mpat en kvalitativ metod med djupg��endehalvstrukturerade intervjuer. F��r att f�� reda p�� hur lokala handlare uppfattar marknaden,konkurrensen och handelsutvecklingen, intervjuades fem stycken strategiskt valdadetaljhandelsf��retag.Av unders��kningen framgick det att en gemensam syn kring marknaden f��religger vilketinnebar att oavsett f��retagens val s�� har f��retagen sitt fokus p�� konsumenten. Det framgick��ven att en av de viktigaste framg��ngsfaktorerna ��r att tillgodose konsumenten med h��gservicegrad och p�� s�� s��tt skapa en relation. Relationer bidrar till ��terkommande och lojalakonsumenter vilket i sin tur bidrar till l��nsamhet f��r f��retaget. Samtliga informanter var enigaom att relationer uppr��ttas i den fysiska butiken och har s��ledes valt att fokusera p�� denenskilda butiken i internets st��ndiga utveckling. F��r att attrahera konsumenter till butiken harde valt att tillhandah��lla ett unikt sortiment. Sammanfattningsvis har internet och handelnsutveckling och den konkurrens det medf��r p�� lokala handlarna blivit tvungna ta st��llning tilldet och anpassa en aff��rsmodell utefter sin egen verksamhet.

Towards a sustainable approach for Cultural Heritage Conservation: developing micro-structured green materials and analytical protocols for their performance assessment

Cleaning is one of the most important and delicate procedures that are part of the restoration process. When developing new systems, it is fundamental to consider its selectivity towards the layer to-be-removed, non-invasiveness towards the one to-be-preserved, its sustainability and non-toxicity. Besides assessing its efficacy, it is important to understand its mechanism by analytical protocols that strike a balance between cost, practicality, and reliable interpretation of results. In this thesis, the development of cleaning systems based on the coupling of electrospun fabrics (ES) and greener organic solvents is proposed. Electrospinning is a versatile technique that allows the production of micro/nanostructured non-woven mats, which have already been used as absorbents in various scientific fields, but to date, not in the restoration field. The systems produced proved to be effective for the removal of dammar varnish from paintings, where the ES not only act as solvent-binding agents but also as adsorbents towards the partially solubilised varnish due to capillary rise, thus enabling a one-step procedure. They have also been successfully applied for the removal of spray varnish from marble substrates and wall paintings. Due to the materials' complexity, the procedure had to be adapted case-by-case and mechanical action was still necessary. According to the spinning solution, three types of ES mats have been produced: polyamide 6,6, pullulan and pullulan with melanin nanoparticles. The latter, under irradiation, allows for a localised temperature increase accelerating and facilitating the removal of less soluble layers (e.g. reticulated alkyd-based paints). All the systems produced, and the mock-ups used were extensively characterised using multi-analytical protocols. Finally, a monitoring protocol and image treatment based on photoluminescence macro-imaging is proposed. This set-up allowed the study of the removal mechanism of dammar varnish and semi-quantify its residues. These initial results form the basis for optimising the acquisition set-up and data processing.

Grant-Free Access for Massive IoT Based on Interference Cancellation and Massive MIMO

Recent years have witnessed an increasing evolution of wireless mobile networks, with an intensive research work aimed at developing new efficient techniques for the future 6G standards. In the framework of massive machine-type communication (mMTC), emerging Internet of Things (IoT) applications, in which sensor nodes and smart devices transmit unpredictably and sporadically short data packets without coordination, are gaining an increasing interest. In this work, new medium access control (MAC) protocols for massive IoT, capable of supporting a non-instantaneous feedback from the receiver, are studied. These schemes guarantee an high time for the acknowledgment (ACK) messages to the base station (BS), without a significant performance loss. Then, an error floor analysis of the considered protocols is performed in order to obtain useful guidelines for the system design. Furthermore, non-orthogonal multiple access (NOMA) coded random access (CRA) schemes based on power domain are here developed. The introduction of power diversity permits to solve more packet collision at the physical (PHY) layer, with an important reduction of the packet loss rate (PLR) in comparison to the number of active users in the system. The proposed solutions aim to improve the actual grant-free protocols, respecting the stringent constraints of scalability, reliability and latency requested by 6G networks.

Asynchronous Massive Machine-Type Access with Massive MIMO

In this thesis asynchronous contention resolution diversity slotted ALOHA (ACRDA) is studied and implemented on computer to simulate a typical massive IoT scenario. Chapter 1 gives a general overview of existing multiple access schemes, reporting their fundamental concepts focusing more on Coded Random Access schemes and their characteristics. In Chapter 2 the asynchronous protocol ACRDA is explained in depth analyzing all parts of the scheme. In the third Chapter the results obtained following various simulations of the asynchronous scheme are reported and their performance are analyzed.

Qualidade da classifica����o do tomate de mesa em unidades de beneficiamento

Quality evaluation of classification was done in two fresh market tomatoes packing house, using electronically and mechanical equipments in two harvest periods, summer and winter seasons. The main goal of this work was to evaluate size and color grading conformity with the standards proposed by the Brazilian Program for Horticulture Modernization and size grading obtainded with the one established by the packer. The cultivar studied was Carmen. The results showed that there was no grade conformity with the fresh tomato quality standards proposed by the Brazilian Program for Horticulture Modernization. The grade conformity obtained when compared with the one programmed by the packer, was only for large sizes, in both equipments. The electronically equipment has presented better performance, over the mechanical, considering grading quality and fruits post-harvest quality. However, the electronically equipment must be constantly monitored to achieve efficiency and investment return. On the other side, for mechanical equipment it will be necessary to review the actual system of size grading, in order to follow the fresh tomato quality standards.

Reduction of Chromium from Al(2)O(3)-CaO-SiO(2)-CrOx Slags by Carbon Dissolved in Liquid Iron

The goal of this work is to investigate the reduction of chromium from a quaternary slag by carbon dissolved in liquid steel. Laboratory scale experiments were conducted to study the reduction of chromium oxides in the slag by carbon dissolved in the melt. These experiments were made under different conditions of slag basicity and amount of added carbon. Thermodynamic calculations based on Double Sublattice model were applied using the commercial software Thermo-Calc, with the IRSID database. The results obtained showed good correlation with practical and calculated results, making it possible to predict equilibrium conditions of the system and to determine the activities of chromium oxides in the slag.

Dietary glutamine supplementation increases the activity of peritoneal macrophages and hemopoiesis in early-weaned mice inoculated with Mycobacterium bovis bacillus Calmette-Guerin

Infants who are breast-fed have been shown to have a lower incidence of certain infectious diseases compared with formula-fed infants. Glutamine is one of the most abundant amino acids found in maternal milk and it is essential for the function of immune system cells such as macrophages. The purpose of this study was to investigate the effect of glutamine supplementation on the function of peritoneal macrophages and on hemopoiesis in early-weaned mice inoculated with Mycobacterium bovis bacillus Calmette-Guerin (BCG). Mice were wearied at 14 d of age and distributed to 2 groups and fed either a glutamine-free diet (n = 16) or a glutamine-supplemented diet (+Gln (n = 16). Both diets were isonitrogenous (with addition of a mixture of nonessential amino acids) and isocaloric. At d 21, 2 subgroups of mice (n = 16) were intraperitoneally injected with BCG and all mice were killed at d 28. Plasma, muscle and liver glutamine concentrations and muscle glutamine synthetase activity were not affected by diet or inoculation with BCG. The +GIn diet led to increased leukocyte and lymphocyte counts in the peripheral blood (P < 0.05) and granulocyte and lymphocyte counts in the bone marrow and spleen (P < 0.05). The +GIn diet increased spreading and adhesion capacities, hydrogen peroxide, nitric oxide, and tumor necrosis factor-alpha (TNF alpha) syntheses and the phagocytic and fungicidal activity of peritoneal macrophages (P < 0.05). The interaction between the +GIn diet and BCG inoculation increased the area under the curve of interleukin (IL)-1 beta and TNF alpha syntheses (P < 0.05). In conclusion, the intake of glutamine increases the function of peritoneal macrophages and hemopoiesis in early-weaned and BCG-inoculated mice. These data have important implications for the design of breast milk substitutes for human infants.

Does Cyclophosphamide Play a Protective Role Against Neuronal Loss in Chronic T. cruzi Infection?

In this study, we verified the possible role of cyclophosphamide (CY) in protecting or not against neuronal losses in young and aged male Calomys callosus chronically infected with the MORC-1 strain of Trypanosoma cruzi through numerical quantification of neurons from the myenteric plexus of the colon and quantification of nitric-oxide concentration (NO) during the acute and chronic phase of infection. For this purpose, groups of young C. callosus were infected with the MORC-1 strain of T. cruzi. A group of infected animals received i.p. 0.2 mg/ml genuxal dissolved in distilled water treatment with CY. NO concentration in aged animals displayed reduced levels when compared to those found in young animals. No significant alterations in the number of neurons were observed in young animals, but for aged ones, a protective role of CY in reducing neuron loss was noted, in addition to enhancing the neuronal volume, area, and perimeter. These results suggest that CY administration, depending on the dose and time span, can act as a protective agent against neuronal losses.

Diabetes induces metabolic alterations in dental pulp

Diabetes can interfere in tissue nutrition and can impair dental pulp metabolism. This disease causes oxidative stress in cells and tissues. However, little is known about the antioxidant system in the dental pulp of diabetics. Thus, it would be of importance to study this system in this tissue in order to verify possible alterations indicative of oxidative stress. The aim of this study was to evaluate some parameters of antioxidant system of the dental pulp of healthy (n = 8) and diabetic rats (n = 8). Diabetes was induced by streptozotocin in rats. Six weeks after diabetes induction, a pool of the dental pulp of the 4 incisors of each rat (healthy and diabetic) was used for the determination of total protein and sialic acid concentrations and catalase and peroxidase activities. Data were compared by a Student t test (p <= 0.05). Dental pulps from both groups presented similar total protein concentrations and peroxidase activity. Dental pulps of diabetic rats exhibited significantly lower free, conjugated, and total sialic acid concentrations than those of control tissues. Catalase activity in diabetic dental pulps was significantly enhanced in comparison with that of control pulps. The result of the present study is indicative of oxidative stress in the dental pulp caused by diabetes. The increase of catalase activity and the reduction of sialic acid could be resultant of reactive oxygen species production.

Quantum dynamics of two coupled qubits

We investigate the difference between classical and quantum dynamics of coupled magnetic dipoles. We prove that in general the dynamics of the classical interaction Hamiltonian differs from the corresponding quantum model, regardless of the initial state. The difference appears as nonpositive-definite diffusion terms in the quantum evolution equation of an appropriate positive phase-space probability density. Thus, it is not possible to express the dynamics in terms of a convolution of a positive transition probability function and the initial condition as can be done in the classical case. It is this feature that enables the quantum system to evolve to an entangled state. We conclude that the dynamics are a quantum element of nuclear magnetic resonance quantum-information processing. There are two limits where our quantum evolution coincides with the classical one: the short-time limit before spin-spin interaction sets in and the long-time limit when phase diffusion is incorporated.

Spatial and temporal patterns in Australian wheat yield and their relationship with ENSO

Spatial and temporal variability in wheat production in Australia is dominated by rainfall occurrence. The length of historical production records is inadequate, however, to analyse spatial and temporal patterns conclusively. In this study we used modelling and simulation to identify key spatial patterns in Australian wheat yield, identify groups of years in the historical record in which spatial patterns were similar, and examine association of those wheat yield year groups with indicators of the El Nino Southern Oscillation (ENSO). A simple stress index model was trained on 19 years of Australian Bureau of Statistics shire yield data (1975-93). The model was then used to simulate shire yield from 1901 to 1999 for all wheat-producing shires. Principal components analysis was used to determine the dominating spatial relationships in wheat yield among shires. Six major components of spatial variability were found. Five of these represented near spatially independent zones across the Australian wheatbelt that demonstrated coherent temporal (annual) variability in wheat yield. A second orthogonal component was required to explain the temporal variation in New South Wales. The principal component scores were used to identify high- and low-yielding years in each zone. Year type groupings identified in this way were tested for association with indicators of ENSO. Significant associations were found for all zones in the Australian wheatbelt. Associations were as strong or stronger when ENSO indicators preceding the wheat season (April-May phases of the Southern Oscillation Index) were used rather than indicators based on classification during the wheat season. Although this association suggests an obvious role for seasonal climate forecasting in national wheat crop forecasting, the discriminatory power of the ENSO indicators, although significant, was not strong. By examining the historical years forming the wheat yield analog sets within each zone, it may be possible to identify novel climate system or ocean-atmosphere features that may be causal and, hence, most useful in improving seasonal forecasting schemes.

Production and photosynthetic activity of Mimosa Verde and Mimosa Roxa lettuce in two farming systems

Lettuce (Lactuca sativa L.) is the most commonly consumed leaf vegetable in the Brazilian diet, and it is a good source of vitamins and minerals. It is widely grown in the conventional farming system. However, the hydroponic farming system has been gaining importance in the market, wining confidence from consumers, who are becoming increasingly more demanding on food quality. The objective of this study was to evaluate the performance of two lettuce cultivars on hydroponic and conventional farming systems for the production of fresh mass (FM) and dry mass (DM), photosynthesis, contents of chlorophyll and anthocyanin. The following two experiments were carried out: hydroponics farming (HF) and conventional farming (CF), performed in protect and unprotect environments, respectively, in Florian��polis, SC. Mimosa Verde cultivar (MV) showed greater fresh mass than Mimosa Roxa (MR), in both farming systems and the two cultivars presented better performance in the hydroponic system (287.7 g MV and 139.1 g MR) than the conventional system (129.7 g MV and 111.8 g MR). Mimosa Verde cultivar presented lower average contents of total chlorophyll (7.7 mg g-�� FM) than Mimosa Roxa (11.8 mg g-��FM), and both cultivars displayed higher means for this variable in the hydroponic farming system. Mimosa Roxa presented higher contents of anthocyanin in the conventional system (88.24 mg g-�� FM) than the ones in the hydroponic system (36.89 mg g-�� FM). The best results for CO2 net assimilation rate regarded to photosyntheticaly active photon flux density were found in the hydroponic system, for both lettuce cultivars. Variation in the contents of chlorophyll were also found. Those variations were higher in the protected system than in the hydroponic system and contents of anthocyanin were higher in the conventional system.

Thinking over b���learning strategy: the MIPO model approach

This article describes the main research results in a new methodology, in which the stages and strategies of the technology integration process are identified and described. A set of principles and recommendations are therefore presented. The MIPO model described in this paper is a result of the effort made regarding the understanding of the main success features of good practices, in the web environment, integrated in the information systems/information technology context. The initial model has been created, based on experiences and literature review. After that, it was tested in the information and technology system units at higher school and also adapted as a result of four cycles of an actionresearch work combined with a case study research. The information, concepts and procedures presented here give support to teachers and instructors, instructional designers and planning teams ��� anyone who wants to develop effective b���learning instructions.