74 resultados para Operational organization


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) are used to investigate molecular organization in Langmuir-Blodgett (LB) films of two kinds of lignins. The lignins were extracted from sugar cane bagasse using distinct extraction processes and are referred to here as ethanol lignin (EL) and saccharification lignin (SAC). AFM images show that LB films from EL have a flat surface in comparison with those from SAC. For the latter, ellipsoidal aggregates are seen oriented perpendicularly to the substrate. This result is confirmed by a combination of transmission and reflection FTIR measurements, which also point to lignin aggregates preferentially oriented perpendicularly to the substrate. For LB films from EL, on the other hand, aggregates are preferentially oriented parallel to the substrate, again consistent with the flat surface observed in AFM data. The vibrational spectroscopy data for cast films from both lignins show random molecular organization, as one should expect.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The structural organization of Sb2O3-SbPO4 glasses has been studied by FTIR, Raman, P-31 MAS and spin echo NMR, Mossbauer and X-ray absorption spectroscopy (EXAFS and XANES at K and L-3,L-1-Sb edges). The combined results can be explained in terms of two potential mechanisms describing the change of the Sb(m) local environment upon incorporation of Q((4))-type phosphate. The formation of the latter species requires anionic compensation that may be adjusted by (a) formation of non bridging oxygen or (b) formation of SbO4E- groups (E = non-bonding electron pair). The second model is favored.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Using food bait stations and colony trap nests, the spatial relation between the foraging activity of established colonies of the polygynous and unicolonial exotic pharaoh's ant, Monomorium pharaonis, and colonization by colony fragments was studied over an 8 month period in a large institutional setting in Brazil. Both foraging activity and colonizations demonstrated significant spatial clumping. However, colonizations were significantly negatively clumped spatially with respect to foraging activity. This suggests that the colonization strategy of this species under the studied conditions was that of complete habitat domination.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Glycogen synthase, an enzyme involved in glycogen biosynthesis, is regulated by phosphorylation and by the allosteric ligand glucose-6-phosphate (G6P). In addition, enzyme levels can be regulated by changes in gene expression. We recently cloned a cDNA for glycogen synthase (gsn) from Neurospora crassa, and showed that gsn transcription decreased when cells were exposed to heat shock (shifted from 30degreesC to 45degreesC). In order to understand the mechanisms that control gsn expression, we isolated the gene, including its 5' and 3' flanking regions, from the genome of N. crassa. An ORF of approximately 2.4 kb was identified, which is interrupted by four small introns (II-V). Intron I (482 bp) is located in the 5'UTR region. Three putative Transcription Initiation Sites (TISs) were mapped, one of which lies downstream of a canonical TATA-box sequence (5'-TGTATAAA-3'). Analysis of the 5'-flanking region revealed the presence of putative transcription factor-binding sites, including Heat Shock Elements (HSEs) and STress Responsive Elements (STREs). The possible involvement of these motifs in the negative regulation of gsn transcription was investigated using Electrophoretic Mobility Shift Assays (EMSA) with nuclear extracts of N. crassa mycelium obtained before and after heat shock, and DNA fragments encompassing HSE and STRE elements from the 5'-flanking region. While elements within the promoter region are involved in transcription under heat shock, elements in the 5'UTR intron may participate in transcription during vegetative growth. The results thus suggest that N. crassa possesses trans-acting elements that interact with the 5'-flanking region to regulate gsn transcription during heat shock and vegetative growth.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The placental vasculature of five hystricomorph rodents was examined by latex injection of the blood vessels, immunohistochemistry and scanning electron microscopy of vessel casts. The pattern of branching of the vessels is described at the level of fine structure. The placenta is divided into lobes separated by interlobular trophoblast. Fetal arteries course through the interlobular areas and give rise to capillaries from which blood drains into veins at the centre of the lobes. Maternal blood reaches the placenta through spiral arteries that pass around the perimeter of the subplacenta. They supply large maternal blood sinuses, lined by trophoblast, which run through the interlobular areas and into the centre of the lobes. Here they supply fine channels that run parallel to the fetal capillaries, so that maternal blood flows from the centre of the lobe to the periphery. This arrangement provides the morphological basis for countercurrent exchange. The maternal channels of the labyrinth drain into spaces formed by the latticework of the interlobular trophoblast and thence through venous lacunae to a basal venous lacunar ring. The subplacenta is supplied by a single fetal artery. The vessels within the subplacenta pursue a tortuous course with dilatations and constrictions as in an endocrine gland. (C) 2003 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There are few reports on the genomic organization of 5S rDNA in fish species. To characterize the 5S rDNA nucleotide sequence and chromosomal localization in the Neotropical fishes of the genus Brycon, 5S rDNA copies from seven species were generated by PCR. The nucleotide sequences of the coding region (5S rRNA gene) and the nontranscribed spacer (NTS) were determined, revealing that the 5S rRNA genes were highly conserved, while the NTSs were widely variable among the species analyzed. Moreover, two classes of NTS were detected in each species, characterized by base substitutions and insertions-deletions. Using fluorescence in situ hybridization (FISH), two 5S rDNA chromosome loci that could be related to the two 5S rDNA NTS classes were observed in at least one of the species studied. 5S rDNA sequencing and chromosomal localization permitted the characterization of Brycon spp. and suggest a higher similarity among some of them. The data obtained indicate that the 5S rDNA can be an useful genetic marker for species identification and evolutionary studies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To address understanding the organization of the 5S rRNA multigene family in the fish genome, the nucleotide sequence and organization array of 5S rDNA were investigated in the genus Leporinus, a representative freshwater fish group of South American fauna. PCR, subgenomic library screening, genomic blotting, fluorescence in situ hybridization, and DNA sequencing were employed in this study. Two arrays of 5S rDNA were identified for all species investigated, one consisting of monomeric repeat units of around 200 bp and another one with monomers of 900 bp. These 5S rDNA arrays were characterized by distinct NTS sequences (designated NTS-I and NTS-II for the 200- and 900-bp monomers, respectively); however, their coding sequences were nearly identical. The 5S rRNA genes were clustered in two chromosome loci, a major one corresponding to the NTS-I sites and a minor one corresponding to the NTS-II sites. The NTS-I sequence was variable among Leporinus spp., whereas the NTS-II was conserved among them and even in the related genus Schizodon. The distinct 5S rDNA arrays might characterize two 5S rRNA gene subfamilies that have been evolving independently in the genome.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effects of massive lesions of the telencephalon on the behavioral repertoire of captive pigeons were investigated. The behavior of four birds with an intact telencephalon was compared to that of four birds submitted to ablation of telencephalic structures. Behavioral audio recording was done according to previously defined categories in three daily sessions for fifteen days. Experimental birds were followed up for one month. Immediately after the lesion, operated birds showed decreases in the occurrence of different behaviors such as coordinated movements, feeding, interaction, preening, maintenance, exploration and vocalization and increases in locomotion and discrete movements of the body when compared to the control birds (P < 0.05). Recovery of exploration (P < 0.05), feeding and localization was observed during the follow-up period. These data are interpreted as suggestive of a functional role of the telencephalon in the organization of behavior and a long-term recovery of behavior after detelencephalation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A case study of convective development in the Southwest Amazon region during the Wet Season Atmospheric Mesoscale Campaign (WETAMC) and Tropical Rainfall Measuring Mission (TRMM)/Large-Scale Biosphere-Atmosphere (LBA) Experiment in Amazonia is presented. The convective development during 7 February 1999 is shown to occur during a period of very weak large-scale forcing in the presence of topography and deforestation. The available data include dual Doppler radar analysis, radiosonde launches, and surface and boundary layer observations. The observational analysis is complemented with a series of model simulations using the RAMS with 2-km resolution over a 300 km 300 km area forced by a morning radiosonde profile. A comparison of the observed and simulated thermodynamic transformation of the boundary layer and of the formation of convective lines, and of their kinematic and microphysical properties is presented. It is shown that only a few very deep and intense convective cells are necessary to explain the overall precipitating line formation and that discrete propagation and coupling with upper atmosphere circulations may explain the appearance of several lines. The numerical simulation indicates that topography may be the cause of initial convective development, although later on the convective line is parallel to the midlevel shear. There are indications that small-scale deforestation may have an effect on increasing rainfall in the wet season when the large-scale forcing is very weak.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The complete nucleotide sequence of the genomic RNA 1 (8745 nt) and RNA 2 (4986 nt) of Citrus leprosis virus cytoplasmic type (CiLV-C) was determined using cloned cDNA. RNA 1 contains two open reading frames (ORFs), which correspond to 286 and 29 kDa proteins. The 286 kDa protein is a polyprotein putatively involved in virus replication, which contains four conserved domains: methyltransferase, protease, helicase and polymerase. RNA 2 contains four ORFs corresponding to 15, 61, 32 and 24 kDa proteins, respectively. The 32 kDa protein is apparently involved in cell-to-cell movement of the virus, but none of the other putative proteins exhibit any conserved domain. The 5' regions of the two genomic RNAs contain a 'cap' structure and poly(A) tails were identified in the 3'-terminals. Sequence analyses and searches for structural and non-structural protein similarities revealed conserved domains with members of the genera Furovirus, Bromovirus, Tobravirus and Tobamovirus, although phylogenetic analyses strongly suggest that CiLV-C is a member of a distinct, novel virus genus and family, and definitely demonstrate that it does not belong to the family Rhabdoviridae, as previously proposed. Based on these results it was proposed that Citrus leprosis virus be considered as the type member of a new genus of viruses, Cilevirus.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective. To investigate the proxy-reported health-related quality of life (HRQOL) and its determinants in patients with juvenile idiopathic arthritis (JIA).Methods. In this multinational, multicenter, cross-sectional study, HRQOL of patients with JIA was assessed through the Child Health Questionnaire (CHQ) and was compared with that of healthy children of similar age from the same geographic area. of joint inflammation, Childhood Health Assessment Questionnaire (CHAQ), and erythrocyte sedimentation rate.Results. A total of 6,639 participants (3,324 with JIA and 3,315 healthy) were enrolled from 32 countries. The mean SD physical and psychosocial summary scores of the CHQ were significantly lower in patients with JIA than in healthy children (physical: 44.5 +/- 10.6 versus 54.6 +/- 4.0, P < 0.0001; psychosocial: 47.6 +/- 8.7 versus 51.9 +/- 7.59 P < 0.0001), with the physical well-being domain being most impaired. Patients with persistent oligoarthritis had better HRQOL compared with other subtypes, whereas HRQOL was similar across patients with systemic arthritis, polyarthritis, and extended oligoarthritis. A CHAQ score > 1 and a pain intensity rating > 3.4 cm on a 10-cm visual analog scale were the strongest determinants of poorer HRQOL in the physical and psychosocial domains, respectively.Conclusion. We found that patients with JIA have a significant impairment of their HRQOL compared with healthy peers, particularly in the physical domain. Physical well-being was mostly affected by the level of functional impairment, whereas the intensity of pain had the greatest influence on psychosocial health.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Common sense tells us that the future is an essential element in any strategy. In addition, there is a good deal of literature on scenario planning, which is an important tool in considering the future in terms of strategy. However, in many organizations there is serious resistance to the development of scenarios, and they are not broadly implemented by companies. But even organizations that do not rely heavily on the development of scenarios do, in fact, construct visions to guide their strategies. But it might be asked, what happens when this vision is not consistent with the future? To address this problem, the present article proposes a method for checking the content and consistency of an organization's vision of the future, no matter how it was conceived. The proposed method is grounded on theoretical concepts from the field of future studies, which are described in this article. This study was motivated by the search for developing new ways of improving and using scenario techniques as a method for making strategic decisions. The method was then tested on a company in the field of information technology in order to check its operational feasibility. The test showed that the proposed method is, in fact, operationally feasible and was capable of analyzing the vision of the company being studied, indicating both its shortcomings and points of inconsistency. (C) 2007 Elsevier Ltd. All rights reserved.