A concepção dos professores sobre o uso do blog na disciplina de matemática

Orientador : Jaime WojciechowskiArtigo (especialização) - Universidade Federal do Paraná, Setor de Educação Profissional e Tecnológica, Curso de Especialização em Mídias Integradas na Educação.Inclui referência

Wartość wirtualnej bronchoskopii tomografii komputerowej w ocenie zmian nowotworowych płuc

Background: The aim of the study was to find an optimal method of bronchial tree examination using CT virtual bronchoscopy and to evaluate the method for its diagnostic accuracy in the assessment of lung malignancies. Additionally, diagnostic accuracy of the used CT system was analyzed. Material/Methods: The examination was conducted in 154 patients from the University Hospital in Cracow and the University Hospital in Leuven (Belgium). The first group of patients was examined using single detector-row HeliCat Flash CT scanner (Philips Medical Systems) in the Department of Radiology of the University Hospital in Cracow. The second group of patients was examined using 16-detectorrow Mx8000 IDT 16 CT scanner (Philips Medical System) in the University Hospital in Leuven, Belgium. Lung lesions were evaluated by their central and segmental localization in bronchial tree and the degree of bronchial tree stenosis was assessed subsequently. Results: It was shown that singleslice CT virtual bronchoscopy allows a reliable evaluation of the lesions with central localization in bronchial tree, while diagnostic accuracy of multislice CT virtual bronchoscopy is comparable with bronchofiberoscopy in the evaluation of lesions with central and segmental localization. Conclusions: As a result of the study it was concluded that type of the used CT system affected the obtained results. Multislice CT is more accurate in assessing the lesions localized in bronchial tree in considerably shorter time

The Canada-UK Deep Submillimetre Survey - VIII. Source identifications in the 3-hour field

We present optical, near-infrared (IR) and radio observations of the 3-hour field of the Canada-UK Deep Submillimetre Survey (CUDSS). Of the 27 submillimetre sources in the field, nine have secure identifications with either a radio source or a near-IR source. We show that the percentage of sources with secure identifications in the CUDSS is consistent with that found for the bright ‘8-mJy' submillimetre survey, once allowance is made for the different submillimetre and radio flux limits. Of the 14 secure identifications in the two CUDSS fields, eight are very red objects (VROs) or extremely red objects (EROs), five have colours typical of normal galaxies and one is a radio source that has not yet been detected at optical/near-IR wavelengths. 11 of the identifications have optical/near-IR structures which are either disturbed or have some peculiarity that suggests that the host galaxy is part of an interacting system. One difference between the CUDSS results and the results from the 8-mJy survey is the large number of low-redshift objects in the CUDSS. We give several arguments why these are genuine low-redshift submillimetre sources rather than being gravitational lenses that are gravitationally amplifying a high-z submillimetre source. We construct a K-z diagram for various classes of high-redshift galaxy and show that the SCUBA galaxies are on average less luminous than classical radio galaxies, but are very similar in both their optical/IR luminosities and their colours to the host galaxies of the radio sources detected in μJy radio survey

Challenges and opportunities for quantifying roots and rhizosphere interactions through imaging and image analysis

The morphology of roots and root systems influences the efficiency by which plants acquire nutrients and water, anchor themselves and provide stability to the surrounding soil. Plant genotype and the biotic and abiotic environment significantly influence root morphology, growth and ultimately crop yield. The challenge for researchers interested in phenotyping root systems is, therefore, not just to measure roots and link their phenotype to the plant genotype, but also to understand how the growth of roots is influenced by their environment. This review discusses progress in quantifying root system parameters (e.g. in terms of size, shape and dynamics) using imaging and image analysis technologies and also discusses their potential for providing a better understanding of root:soil interactions. Significant progress has been made in image acquisition techniques, however trade-offs exist between sample throughput, sample size, image resolution and information gained. All of these factors impact on downstream image analysis processes. While there have been significant advances in computation power, limitations still exist in statistical processes involved in image analysis. Utilizing and combining different imaging systems, integrating measurements and image analysis where possible, and amalgamating data will allow researchers to gain a better understanding of root:soil interactions

The Canada-UK Deep Submillimetre Survey VIII: Source Identifications in the 3-hour field

We present optical, near-infrared and radio observations of the 3-hour field of the Canada-UK Deep Submillimetre Survey. Of the 27 submillimetre sources in the field, nine have secure identifications with either a radio source or a near-IR source. We show that the percentage of sources with secure identifications in the CUDSS is consistent with that found for the bright `8 mJy' submillimetre survey, once allowance is made for the different submillimetre and radio flux limits. Of the 14 secure identifications in the two CUDSS fields, eight are VROs or EROs, five have colours typical of normal galaxies, and one is a radio source which has not yet been detected at optical/near-IR wavelengths. Eleven of the identifications have optical/near-IR structures which are either disturbed or have some peculiarity which suggests that the host galaxy is part of an interacting system. One difference between the CUDSS results and the results from the 8-mJy survey is the large number of low-redshift objects in the CUDSS; we give several arguments why these are genuine low-redshift submillimetre sources rather than being gravitational lenses which are gravitationally amplifying a high-$z$ submillimetre source. We construct a $K-z$ diagram for various classes of high-redshift galaxy and show that the SCUBA galaxies are on average less luminous than classical radio galaxies, but are very similar in both their optical/IR luminosities and their colours to the host galaxies of the radio sources detected in $\mu$Jy radio surveys.Comment: accepted for publication in MNRAS, 18 pages, full-resolution versions of Figure 1 and 2 can be found at http://www.astro.cf.ac.uk/groups/cosmo/papers.htm

Alteration of cell-wall porosity is involved in osmotic stress-induced enhancement of aluminium resistance in common bean (Phaseolus vulgaris L.)

Aluminium (Al) toxicity and drought are the two major abiotic stress factors limiting common bean production in the tropics. Using hydroponics, the short-term effects of combined Al toxicity and drought stress on root growth and Al uptake into the root apex were investigated. In the presence of Al stress, PEG 6000 (polyethylene glycol)-induced osmotic (drought) stress led to the amelioration of Al-induced inhibition of root elongation in the Al-sensitive genotype VAX 1. PEG 6000 (>> PEG 1000) treatment greatly decreased Al accumulation in the 1 cm root apices even when the roots were physically separated from the PEG solution using dialysis membrane tubes. Upon removal of PEG from the treatment solution, the root tips recovered from osmotic stress and the Al accumulation capacity was quickly restored. The PEG-induced reduction of Al accumulation was not due to a lower phytotoxic Al concentration in the treatment solution, reduced negativity of the root apoplast, or to enhanced citrate exudation. Also cell-wall (CW) material isolated from PEG-treated roots showed a low Al-binding capacity which, however, was restored after destroying the physical structure of the CW. The comparison of the Al3+, La3+, Sr2+, and Rb+ binding capacity of the intact root tips and the isolated CW revealed the specificity of the PEG 6000 effect for Al. This could be due to the higher hydrated ionic radius of Al3+ compared with other cations (Al3+ >> La3+ > Sr2+ > Rb+). In conclusion, the results provide circumstantial evidence that the osmotic stress-inhibited Al accumulation in root apices and thus reduced Al-induced inhibition of root elongation in the Al-sensitive genotype VAX 1 is related to the alteration of CW porosity resulting from PEG 6000-induced dehydration of the root apoplast

A Downstream CpG Island Controls Transcript Initiation and Elongation and the Methylation State of the Imprinted Airn Macro ncRNA Promoter

A CpG island (CGI) lies at the 5′ end of the Airn macro non-protein-coding (nc) RNA that represses the flanking Igf2r promoter in cis on paternally inherited chromosomes. In addition to being modified on maternally inherited chromosomes by a DNA methylation imprint, the Airn CGI shows two unusual organization features: its position immediately downstream of the Airn promoter and transcription start site and a series of tandem direct repeats (TDRs) occupying its second half. The physical separation of the Airn promoter from the CGI provides a model to investigate if the CGI plays distinct transcriptional and epigenetic roles. We used homologous recombination to generate embryonic stem cells carrying deletions at the endogenous locus of the entire CGI or just the TDRs. The deleted Airn alleles were analyzed by using an ES cell imprinting model that recapitulates the onset of Igf2r imprinted expression in embryonic development or by using knock-out mice. The results show that the CGI is required for efficient Airn initiation and to maintain the unmethylated state of the Airn promoter, which are both necessary for Igf2r repression on the paternal chromosome. The TDRs occupying the second half of the CGI play a minor role in Airn transcriptional elongation or processivity, but are essential for methylation on the maternal Airn promoter that is necessary for Igf2r to be expressed from this chromosome. Together the data indicate the existence of a class of regulatory CGIs in the mammalian genome that act downstream of the promoter and transcription start

Biological flora of Central europe: Baldellia ranunculoides (Alismataceae)

Baldellia ranunculoides (L.) Parl. (Alismataceae) is a taxonomically problematic aquatic plant with an historically ill-defined distribution and global conservation status. This paper finds morphological, ecological and molecular evidence for two distinct taxa, probably best described as subspecies: (1) B. ranunculoides subsp. ranunculoides and (2) B. ranunculoides subsp. repens and provides detailed distribution data on their overlapping range, in different habitats, across the cool, high rainfall areas of western Europe and west Mediterranean. The two subspecies are amongst the relatively large number of threatened European and north Africa aquatic plants and this paper provides a systematic review of their relative conservation pressures and management needs, with particular emphasis on the status of both taxa in central Europe. Other observations indicate probable evolutionary relationships within B. ranunculoides s.l. and its associated taxa and the review points out where these and other research topics could potentially be pursued

Gulf Coast salt domes

Master of ScienceGeologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/115777/1/39015003273896.pd