FÓSFORO: DE NUTRIENTE À POLUENTE!

http://dx.doi.org/10.5902/223611706430Phosphorus is an essential element for plants and animals. The nutrient is widely used incultivation areas, but when applied to the soil in high quantities have pollution potential especiallyin surface waters, but Brazilian law does not recognize with polluter. When contaminant causeeutrophication of waters and fish kills. Phosphorus is difficult to recover, but control measures asconservation practices, sizing and use of fertilizer plants extractors (pasture) can be used. Theobjective of the review was to present the basic aspects of the dynamics of phosphorus in the soil,and use as nutrient pollution potential.http://dx.doi.org/10.5902/223611706430O fósforo é um elemento essencial a plantas e animais. Este nutriente é largamente utilizado em áreas de cultivo, mas, quando aplicado ao solo em demasia têm potencial poluidor especialmente em águas superficiais, porém a legislação brasileira não o reconhece com este potencial. Quando contaminante causa eutrofização das águas e mortandade de peixes. O fósforo é de difícil recuperação, porém medidas de controle como práticas conservacionistas, dimensionamento de adubações e uso de plantas extratoras (pastagens) podem ser adotadas. O objetivo da revisão foi apresentar aspectos básicos da dinâmica do fósforo no solo, uso como nutriente e potencial poluente

Corticothalamic feedback sculpts visual spatial integration in mouse thalamus

En route from retina to cortex, visual information travels through the dorsolateral geniculate nucleus of the thalamus (dLGN), where extensive cortico-thalamic (CT) feedback has been suggested to modulate spatial processing. How this modulation arises from direct excitatory and indirect inhibitory CT feedback components remains enigmatic. We show that in awake mice topographically organized cortical feedback modulates spatial integration in dLGN by sharpening receptive fields (RFs) and increasing surround suppression. Guided by a network model revealing wide-scale inhibitory CT feedback necessary to reproduce these effects, we targeted the visual sector of the thalamic reticular nucleus (visTRN) for recordings. We found that visTRN neurons have large receptive fields, show little surround suppression, and have strong feedback-dependent responses to large stimuli, making them an ideal candidate for mediating feedback-enhanced surround suppression in dLGN. We conclude that cortical feedback sculpts spatial integration in dLGN, likely via recruitment of neurons in visTRN

Managing a document-based information space

We present a novel user interface in the form of a complementary virtual environment for managing personal document archives, i.e., for document filing and retrieval. Our implementation of a spatial medium for document interaction, exploratory search and active navigation plays to the strengths of human visual information processing and further stimulates it. Our system provides a high degree of immersion so that the user readily forgets the artificiality of our environment. Three well-integrated features support this immersion: first, we enable users to interact more naturally through gestures and postures (the system can be taught custom ones); second, we exploit 3D display technology; and third, we allow users to manage arrangements (manually edited structures, as well as computer-generated semantic structures). Our ongoing evaluation indicates that even non-expert users can efficiently work with the information in a document collection and that the process can actually be enjoyable. ACM Classification: H5.2 [Information interfaces and presentation]

A Single Peroxisomal Targeting Signal Mediates Matrix Protein Import in Diatoms

Peroxisomes are single membrane bound compartments. They are thought to be present in almost all eukaryotic cells, although the bulk of our knowledge about peroxisomes has been generated from only a handful of model organisms. Peroxisomal matrix proteins are synthesized cytosolically and posttranslationally imported into the peroxisomal matrix. The import is generally thought to be mediated by two different targeting signals. These are respectively recognized by the two import receptor proteins Pex5 and Pex7, which facilitate transport across the peroxisomal membrane. Here, we show the first in vivo localization studies of peroxisomes in a representative organism of the ecologically relevant group of diatoms using fluorescence and transmission electron microscopy. By expression of various homologous and heterologous fusion proteins we demonstrate that targeting of Phaeodactylum tricornutum peroxisomal matrix proteins is mediated only by PTS1 targeting signals, also for proteins that are in other systems imported via a PTS2 mode of action. Additional in silico analyses suggest this surprising finding may also apply to further diatoms. Our data suggest that loss of the PTS2 peroxisomal import signal is not reserved to Caenorhabditis elegans as a single exception, but has also occurred in evolutionary divergent organisms. Obviously, targeting switching from PTS2 to PTS1 across different major eukaryotic groups might have occurred for different reasons. Thus, our findings question the widespread assumption that import of peroxisomal matrix proteins is generally mediated by two different targeting signals. Our results implicate that there apparently must have been an event causing the loss of one targeting signal even in the group of diatoms. Different possibilities are discussed that indicate multiple reasons for the detected targeting switching from PTS2 to PTS1

Peroxisome assembly: matrix and membrane protein biogenesis

The biogenesis of peroxisomal matrix and membrane proteins is substantially different from the biogenesis of proteins of other subcellular compartments, such as mitochondria and chloroplasts, that are of endosymbiotic origin. Proteins are targeted to the peroxisome matrix through interactions between specific targeting sequences and receptor proteins, followed by protein translocation across the peroxisomal membrane. Recent advances have shed light on the nature of the peroxisomal translocon in matrix protein import and the molecular mechanisms of receptor recycling. Furthermore, the endoplasmic reticulum has been shown to play an important role in peroxisomal membrane protein biogenesis. Defining the molecular events in peroxisome assembly may enhance our understanding of the etiology of human peroxisome biogenesis disorders

Style of Lecture Notes in Computer Science (LNCS) Results of a Study on Invoice-Reading Systems in Germany

Abstract. Companies order, receive, and pay for goods. Hence they continually receive and process invoices. For the most part these are printed on paper and are dealt with manually, so that each invoice after receipt involves processing costs of about 9 Euro on average. Often, human searching and typing of data into computer forms is required to transfer the information from paper into the computer, e.g. into ERP-systems, like SAP, that many companies run. This article presents the main results of our 300-page market survey of 11 suppliers of invoice reading systems (   ¢¡¤£¥¡§ ¦), which automate the transfer of invoice data to ERP-systems. For the scientific  ¢¡¤£¥¡¨¦ community we hope to provide the service of a better visibility of our discipline to potential investors and users.

Evaluating SEE - A Benchmarking System for Document Page Segmentation

The decomposition of a document into segments such as text regions and graphics is a significant part of the document analysis process. The basic requirement for rating and improvement of page segmentation algorithms is systematic evaluation. The approaches known from the literature have the disadvantage that manually generated reference data (zoning ground truth) are needed for the evaluation task. The effort and cost of the creation of these data are very high