Estudi de xarxes WPAN 802.15.4

Aquest projecte proposa l'estudi en profunditat de les característiques de les xarxes WPAN 802.15.4 i de les xarxes ZigBee.

Identificação de microcistina LR ao nível molecular empregando microscopia de força atômica

Microcystins are non-ribosomal peptides that must be detected for its health concern. Here, microcystin LR and its specific antibody were respectively tethered to the substrate and to the tip of an atomic force microscope, after surface functionalization using 3-aminopropyltriethoxysilane and glutaraldehyde. Functionalization was confirmed comparing topographic images taken on bare and modified tips. Force versus distance curves were successfully used to measure the specific antibody-antigen interactions comparing with a control in which microcystin was initially blocked by incubation with free antibodies. The results showed unequivocally the specific recognition of MLR, suggesting that this method could be useful for biosensor development.

Postulação de genes (Lr) de resistência à ferrugem da folha em cultivares brasileiras de trigo

Vinte e dois isolados que diferem quanto aos genes de avirulência/virulência de Puccinia triticina foram inoculados em 55 genótipos de trigo (Triticum aestivum) selecionados entre os recomendados e em experimentação na região sul e centro sul do Brasil nos anos de 1996 e/ou 1997 e em linhas monogênicas para genes (Lr) de resistência à ferrugem da folha, no estádio de plântula. Os tipos de infecção dos genótipos portadores, cada um de distinto gene Lr conhecido foram comparados com os dos genótipos brasileiros, para determinar a existência de possíveis genes de resistência nestes. Os genes de plântula identificados com mais freqüência nas cultivares e linhagens brasileiras foram: Lr26, Lr23, Lr10 e Lr24. O gene Lr16, que confere resistência moderada à maioria das raças, foi encontrado em apenas dois genótipos. Muitos dos trigos analisados possuem um ou mais genes Lr provavelmente ainda não descritos.

Estudo da presença da toxina microcistina-LR em água utilizada em clínica de hemodiálise e validação de um método análítico

Algumas cepas de algas, em especial as cianobactérias, podem produzir toxinas como as microcistinas, as quais podem ocasionar intoxicação e morte de seres humanos e de animais. A literatura reporta a ocorrência de um acidente em uma clínica de hemodiálise de Caruaru, Pernambuco, aonde vieram a falecer 60 pacientes que faziam hemodiálise, devido à presença da toxina microcistina-LR na água. Nesse estudo foi desenvolvido e validado um método analítico, para a determinação e quantificação da microcistina-LR. A cromatografia líquida de alta performance com detector de UV foi empregada como técnica analítica para a determinação de microcistina-LR. Os parâmetros selecionados para a validação do método foram: linearidade, curva analítica, precisão, sensibilidade e ensaios de recuperação. A curva analítica foi construída com sete pontos a partir do padrão. O método apresentou uma linearidade no intervalo de 0,05 a 5 µg L-1, e o coeficiente de correlação foi superior a 0,99. Com base nestes resultados conclui-se que o método é eficiente e pode ser empregado, em futuras análises, para o monitoramento da microcistina-LR em água utilizada em clínicas de hemodiálise.

Effects of microcystin-LR in isolated perfused rat kidney

Microcystin is a hepatotoxic peptide which inhibits protein phosphatase types 1 and 2A. The objective of the present study was to evaluate the physiopathologic effects of microcystin-LR in isolated perfused rat kidney. Adult Wistar rats (N = 5) of both sexes (240-280 g) were utilized. Microcystin-LR (1 µg/ml) was perfused over a period of 120 min, during which samples of urine and perfusate were collected at 10-min intervals to determine the levels of inulin, sodium, potassium and osmolality. We observed a significant increase in urinary flow with a peak effect at 90 min (control (C) = 0.20 ± 0.01 and treated (T) = 0.32 ± 0.01 ml g-1 min-1, P<0.05). At 90 min there was a significant increase in perfusate pressure (C = 129.7 ± 4.81 and T = 175.0 ± 1.15 mmHg) and glomerular filtration rate (C = 0.66 ± 0.07 and T = 1.10 ± 0.04 ml g-1 min-1) and there was a significant reduction in fractional sodium tubular transport at 120 min (C = 78.6 ± 0.98 and T = 73.9 ± 0.95%). Histopathologic analysis of the perfused kidneys showed protein material in the urinary space, suggestive of renal toxicity. These data demonstrate renal vascular, glomerular and urinary effects of microcystin-LR, indicating that microcystin acts directly on the kidney by probable inhibition of protein phosphatases.

Decadal predictability of the Atlantic meridional overturning circulation and climate in the IPSL-CM5A-LR model

This study explores the decadal potential predictability of the Atlantic Meridional Overturning Circulation (AMOC) as represented in the IPSL-CM5A-LR model, along with the predictability of associated oceanic and atmospheric fields. Using a 1000-year control run, we analyze the prognostic potential predictability (PPP) of the AMOC through ensembles of simulations with perturbed initial conditions. Based on a measure of the ensemble spread, the modelled AMOC has an average predictive skill of 8 years, with some degree of dependence on the AMOC initial state. Diagnostic potential predictability of surface temperature and precipitation is also identified in the control run and compared to the PPP. Both approaches clearly bring out the same regions exhibiting the highest predictive skill. Generally, surface temperature has the highest skill up to 2 decades in the far North Atlantic ocean. There are also weak signals over a few oceanic areas in the tropics and subtropics. Predictability over land is restricted to the coastal areas bordering oceanic predictable regions. Potential predictability at interannual and longer timescales is largely absent for precipitation in spite of weak signals identified mainly in the Nordic Seas. Regions of weak signals show some dependence on AMOC initial state. All the identified regions are closely linked to decadal AMOC fluctuations suggesting that the potential predictability of climate arises from the mechanisms controlling these fluctuations. Evidence for dependence on AMOC initial state also suggests that studying skills from case studies may prove more useful to understand predictability mechanisms than computing average skill from numerous start dates.

Microcystins -LA, -YR, and -LR action on neutrophil migration

Microcystins (MCs) produced by some freshwater cyanobacterial species possess potent liver toxicity as evidenced by acute neutrophil infiltration. Here, we investigate the ability of three structurally distinct toxins (MC-LA, MC-LR, and MC-YR) to evoke neutrophil recruitment per se and their effects on migration pathways. Intravital Microscopic Studies showed that topical application of only MC-LR enhanced the numbers of rolling and adhered leukocytes in the endothelium of postcapillary mesenteric venules. The latter effects may be dependent upon induction of the synthesis and expression Of L-selectin and beta(2)-integrin in neutrophils, as assessed by flow cytometry and RT-PCR, respectively. Conversely, the three toxins promoted direct locomotion of neutrophils and enhanced their migration in response to NO, as measured by Boyden chamber assays, and increased intracellular calcium, a messenger in the chemotaxic process. In conclusion, our results show that MCs act on specific pathways of neutrophil recruitment, indicating their potential effect on neutrophils activation. (C) 2009 Elsevier Inc. All rights reserved.

Att leva som man lär : Implementering av företagskultur vid företagsförvärv

Så mycket som 83 % av alla företagsförvärv misslyckas med att öka aktieägarvärde och hela 53 % minskar till och med i aktieägarvärde (Daniel & Metcalf, 2001). Det är mycket lättare att göra själva affären, än att få den att fungera menar Nguyen & Kleiner (2003). Misslyckade företagsförvärv beror oftast på kulturella skillnader mellan företag och implementering av företagskultur är en nyckelfaktor för ett framgångsrikt företagsförvärv (Lodofors & Boateng, 2006). Syftet är att undersöka implementering av företagskultur efter ett företagsförvärv och att kartlägga ledningens och mellanchefernas egna upplevelser av framgångsfaktorer och svårigheter under processen. I den teoretiska referensramen definieras företagskultur och beskrivs utifrån ett flertal kulturella nivåer där värderingar får särskild uppmärksamhet då studien fokuserar på värdegrundsarbete. Det görs även en beskrivning av olika sätt att utveckla kulturer på. Vidare beskrivs faktorer som ledning och chefer bör ta hänsyn till vid implementering av företagskultur. Dessa är ledarskap, förtroende och lärande (Schein, 2010, Nguyen & Kleiner, 2003, Lakshman, 2011, Bijlsma-Frankema, 2001 m.fl.). För att undersöka studiens syfte har en kvalitativ metod med semistrukturerade intervjuer genomförts. Undersökningen grundar sig på intervjuer med ledning och mellanchefer på Fastighetsbolaget AB. Resultatet visar att bolagets implementering av värderingar upplevs av de flesta respondenter som väldigt framgångsrik. Framgångsfaktorer i deras värdegrundsarbete sammanfattas med att ta det bästa av två världar, anpassa struktur efter önskad kultur, leva som man lär, ha transparens i information och beslut, skapa en gemensam syn på värderingar och uppföljning av medarbetares upplevelser. Den svårighet som diskuteras är kring att skapa en gemensam värdegrund i hela bolaget. Studiens slutsats är att implementering av företagskultur efter ett företagsförvärv handlar om att ledare måste leva som de lär och att ledningen måste skapa förutsättningar för det och arbeta med uppföljning av medarbetares upplevelser.

Microcystin-LR in Brazilian Aquaculture Production Systems

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

Antenas de microfita com patch quase-fractal para aplicações em Redes WPAN/WLAN

The microstrip antennas are in constant evidence in current researches due to several advantages that it presents. Fractal geometry coupled with good performance and convenience of the planar structures are an excellent combination for design and analysis of structures with ever smaller features and multi-resonant and broadband. This geometry has been applied in such patch microstrip antennas to reduce its size and highlight its multi-band behavior. Compared with the conventional microstrip antennas, the quasifractal patch antennas have lower frequencies of resonance, enabling the manufacture of more compact antennas. The aim of this work is the design of quasi-fractal patch antennas through the use of Koch and Minkowski fractal curves applied to radiating and nonradiating antenna s edges of conventional rectangular patch fed by microstrip inset-fed line, initially designed for the frequency of 2.45 GHz. The inset-fed technique is investigated for the impedance matching of fractal antennas, which are fed through lines of microstrip. The efficiency of this technique is investigated experimentally and compared with simulations carried out by commercial software Ansoft Designer used for precise analysis of the electromagnetic behavior of antennas by the method of moments and the neural model proposed. In this dissertation a study of literature on theory of microstrip antennas is done, the same study is performed on the fractal geometry, giving more emphasis to its various forms, techniques for generation of fractals and its applicability. This work also presents a study on artificial neural networks, showing the types/architecture of networks used and their characteristics as well as the training algorithms that were used for their implementation. The equations of settings of the parameters for networks used in this study were derived from the gradient method. It will also be carried out research with emphasis on miniaturization of the proposed new structures, showing how an antenna designed with contours fractals is capable of a miniaturized antenna conventional rectangular patch. The study also consists of a modeling through artificial neural networks of the various parameters of the electromagnetic near-fractal antennas. The presented results demonstrate the excellent capacity of modeling techniques for neural microstrip antennas and all algorithms used in this work in achieving the proposed models were implemented in commercial software simulation of Matlab 7. In order to validate the results, several prototypes of antennas were built, measured on a vector network analyzer and simulated in software for comparison

Prolapse-free relativistic Gaussian basis sets for the superheavy elements up to Uuo (Z=118) and Lr (Z=103)

Prolapse-free basis sets suitable for four-component relativistic quantum chemical calculations are presented for the superheavy elements UP to (118)Uuo ((104)Rf, (105)Db, (106)Sg, (107)Bh, (108)Hs, (109)Mt, (110)Ds, (111)Rg, (112)Uub, (113)Uut, (114)Uuq, (115)Uup, (116)Uuh, (117)Uus, (118)Uuo) and Lr-103. These basis sets were optimized by minimizing the absolute values of the energy difference between the Dirac-Fock-Roothaan total energy and the corresponding numerical value at a milli-Hartree order of magnitude, resulting in a good balance between cost and accuracy. Parameters for generating exponents and new numerical data for some superheavy elements are also presented. (c) 2007 Elsevier B.V. All rights reserved.

Degradation of [D-Leu]-Microcystin-LR by solar heterogeneous photocatalysis (TiO2)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Transporter protein genes are differentially expressed in Acidithiobacillus ferrooxidans LR maintained in contact with covellite

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

Ferric iron uptake genes are differentially expressed in the presence of copper sulfides in Acidithiobacillus ferrooxidans strain LR

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)