973 resultados para Coordinates.
Resumo:
Guava response to liming and fertilization can be monitored by tissue testing. Tissue nutrient signature is often diagnosed against nutrient concentration standards. However, this approach has been criticized for not considering nutrient interactions and to generate numerical biases as a result of data redundancy, scale dependency and non-normal distribution. Techniques of compositional data analysis can control those biases by balancing groups of nutrients, such as those involved in liming and fertilization. The sequentially arranged and orthonormal isometric log ratios (ilr) or balances avoid numerical bias inherent to compositional data. The objectives were to relate tissue nutrient balances with the production of "Paluma" guava orchards differentially limed and fertilized, and to adjust the current patterns of nutrient balance with the range of more productive guava trees. It was conducted one experiment of 7-yr of liming and three experiments of 3-yr with N, P and K trials in 'Paluma' orchards on an Oxisol. Plant N, P, K, Ca and Mg were monitored yearly. It was selected the [N, P, K | Ca, Mg], [N, P | K], [N | P] and [Ca | Mg] balances to set apart the effects of liming (Ca-Mg) and fertilizers (N-K) on macronutrient balances. Liming largely influenced nutrient balances of guava in the Oxisol while fertilization was less influential. The large range of guava yields and nutrient balances allowed defining balance ranges and comparing them with the critical ranges of nutrient concentration values currently used in Brazil and combined into ilr coordinates.
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The current high competition on Citrus industry demands from growers new management technologies for superior efficiency and sustainability. In this context, precision agriculture (PA) has developed techniques based on yield mapping and management systems that recognize field spatial variability, which contribute to increase profitability of commercial crops. Because spatial variability is often not perceived the orange orchards are still managed as uniform and adoption of PA technology on citrus farms is low. Thus, the objective of the present study was to characterize the spatial variability of three factors: fruit yield, soil fertility and occurrence of plant gaps caused by either citrus blight or huanglongbing (HLB) in a commercial Valencia orchard in Brotas, São Paulo State, Brazil. Data from volume, geographic coordinates and representative area of the bags used on harvest were recorded to generate yield points that were then interpolated to produce the yield map. Soil chemical characteristics were studied by analyzing samples collected along planting rows and inter-rows in 24 points distributed in the field. A map of density of tree gaps was produced by georeferencing individual gaps and later by counting the number of gaps within 500 m² cells. Data were submitted to statistical and geostatistical analyses. A t test was used to compare means of soil chemical characteristics between sampling regions. High variation on yield and density of tree gaps was observed from the maps. It was also demonstrated overlapping regions of high density of plant absence and low fruit yield. Soil fertility varied depending on the sampling region in the orchard. The spatial variability found on yield, soil fertility and on disease occurrence demonstrated the importance to adopt site specific nutrient management and disease control as tools to guarantee efficiency of fruit production.
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Electrical resistivity tomography (ERT) is a well-established method for geophysical characterization and has shown potential for monitoring geologic CO2 sequestration, due to its sensitivity to electrical resistivity contrasts generated by liquid/gas saturation variability. In contrast to deterministic inversion approaches, probabilistic inversion provides the full posterior probability density function of the saturation field and accounts for the uncertainties inherent in the petrophysical parameters relating the resistivity to saturation. In this study, the data are from benchtop ERT experiments conducted during gas injection into a quasi-2D brine-saturated sand chamber with a packing that mimics a simple anticlinal geological reservoir. The saturation fields are estimated by Markov chain Monte Carlo inversion of the measured data and compared to independent saturation measurements from light transmission through the chamber. Different model parameterizations are evaluated in terms of the recovered saturation and petrophysical parameter values. The saturation field is parameterized (1) in Cartesian coordinates, (2) by means of its discrete cosine transform coefficients, and (3) by fixed saturation values in structural elements whose shape and location is assumed known or represented by an arbitrary Gaussian Bell structure. Results show that the estimated saturation fields are in overall agreement with saturations measured by light transmission, but differ strongly in terms of parameter estimates, parameter uncertainties and computational intensity. Discretization in the frequency domain (as in the discrete cosine transform parameterization) provides more accurate models at a lower computational cost compared to spatially discretized (Cartesian) models. A priori knowledge about the expected geologic structures allows for non-discretized model descriptions with markedly reduced degrees of freedom. Constraining the solutions to the known injected gas volume improved estimates of saturation and parameter values of the petrophysical relationship. (C) 2014 Elsevier B.V. All rights reserved.
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Non-vertebrate chordates, specifically amphioxus, are considered of the utmost interest for gaining insight into the evolutionary trends, i.e. differentiation and specialization, of gene/protein systems. In this work, MTs (metallothioneins), the most important metal binding proteins, are characterized for the first time in the cephalochordate subphylum at both gene and protein level, together with the main features defining the amphioxus response to cadmium and copper overload. Two MT genes (BfMT1 and BfMT2) have been identified in a contiguous region of the genome, as well as several ARE (antioxidant response element) and MRE (metal response element) located upstream the transcribed region. Their corresponding cDNAs exhibit identical sequence in the two lancelet species (B. floridae and B. lanceolatum), BfMT2 cDNA resulting from an alternative splicing event. BfMT1 is a polyvalent metal binding peptide that coordinates any of the studied metal ions (Zn, Cd or Cu) rendering complexes stable enough to last in physiological environments, which is fully concordant with the constitutive expression of its gene, and therefore, with a metal homeostasis housekeeping role. On the contrary, BfMT2 exhibits a clear ability to coordinate Cd(II) ions, while it is absolutely unable to fold into stable Cu (I) complexes, even as mixed species. This identifies it as an essential detoxification agent, which is consequently only induced in emergency situations. The cephalochordate MTs are not directly related to vertebrate MTs, neither by gene structure, protein similarity nor metal-binding behavior of the encoded peptides. The closest relative is the echinoderm MT, which confirm proposed phylogenetic relationships between these two groups. The current findings support the existence in most organisms of two types of MTs as for their metal binding preferences, devoted to different biological functions: multivalent MTs for housekeeping roles, and specialized MTs that evolve either as Cd-thioneins or Cu-thioneins, according to the ecophysiological needs of each kind of organisms.
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Sähköiset huutokaupat ovat virtuaalisia markkinapaikkoja, jotka sijaitsevat jossain päin internetiä. Sähköistä huutokauppaa käydään yritysten välillä (B2B), yritysten ja kuluttajien välillä (B2C) sekä kuluttajien kesken (C2C). Tässä työssä sähköisellä huutokaupalla tarkoitetaan ensin mainittua, yritysten keskinäistä kaupankäyntiä. Työn tarkoituksena on tutkia työnkulkukoneen soveltuvuutta sähköisen huutokauppajärjestelmän moottorina. Työssä perehdytään avoimen lähdekoodin ActiveBPEL-koneeseen, ja tutkimus tapahtuu suunnittelemalla, mallintamalla ja testaamalla liiketoimintaprosessi, joka rekisteröi ostajan ja myyjän tiedot järjestelmään. Toteutettava prosessi on yksi osa sähköistä huutokauppaa, mutta saman periaatteen mukaisesti olisi mahdollista toteuttaa myös kokonainen huutokauppa. Tässä työssä tarkastellaan sähköistä huutokauppaa, joka perustuu web-palveluihin, ja jolla on selvä koordinaattori. Koordinaattori ohjaa toisia mukana olevia web-palveluja ja niiden ajettavia operaatioita. Korkean tason mallit kuvataan BPMN-notaation avulla, itse prosessi toteutetaan BPEL-kielellä. Prosessin mallinnuksessa ja simuloinnissa käytetään apuna ActiveBPEL Designer -ohjelmaa. Työn tavoitteena on paitsi toteuttaa osa huutokaupasta, myös antaa lukijalle käsitys siitä liiketoimintaympäristöstä, johon huutokauppa kuuluu, sekä valottaa huutokaupan taustalla olevia teknologioita. Erityisesti web-palvelut ja niihin liittyvät käsitteet tulevat lukijalle tutuiksi.
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In an attempt to increase the number of known microquasars, Paredes et al. (2002) have presented a long-term project focused on the search for new objects of this type. They performed a cross-identification between X-ray and radio catalogs under very restrictive selection criteria for sources with |b|<5 degrees, and obtained a sample of 13 radio-emitting X-ray sources. Follow-up observations of 6 of these sources with the VLA provided accurate coordinates, which were used to discover optical counterparts for all of them. We have observed these six sources with the EVN and MERLIN at 5 GHz. Five of the six objects have been detected and imaged, presenting different morphologies: one source has a two-sided jet, three sources have one-sided jets, and one source is compact. With all the presently available information, we conclude that two of the sources are promising microquasar candidates in our Galaxy.
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Within the special geometry of the simplex, the sample space of compositional data, compositional orthonormal coordinates allow the application of any multivariate statistical approach. The search for meaningful coordinates has suggested balances (between two groups of parts)—based on a sequential binary partition of a D-part composition—and a representation in form of a CoDa-dendrogram. Projected samples are represented in a dendrogram-like graph showing: (a) the way of grouping parts; (b) the explanatory role of subcompositions generated in the partition process; (c) the decomposition of the variance; (d) the center and quantiles of each balance. The representation is useful for the interpretation of balances and to describe the sample in a single diagram independently of the number of parts. Also, samples of two or more populations, as well as several samples from the same population, can be represented in the same graph, as long as they have the same parts registered. The approach is illustrated with an example of food consumption in Europe
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Reggies/flotillins are implicated in trafficking of membrane proteins to their target sites and in the regulation of the Rab11a-dependent targeted recycling of E-cadherin to adherens junctions (AJs). Here we demonstrate a function of reggies in focal adhesion (FA) formation and α5- and β1-integrin recycling to FAs. Downregulation of reggie-1 in HeLa and A431 cells by siRNA and shRNA increased the number of FAs, impaired their distribution and modified FA turnover. This was coupled to enhanced focal adhesion kinase (FAK) and Rac1 signaling and gain in plasma membrane motility. Wild type and constitutively-active (CA) Rab11a rescued the phenotype (normal number of FAs) whereas dominant-negative (DN) Rab11a mimicked the loss-of-reggie phenotype in control cells. That reggie-1 affects integrin trafficking emerged from the faster loss of internalized antibody-labeled β1-integrin in reggie-deficient cells. Moreover, live imaging using TIRF microscopy revealed vesicles containing reggie-1 and α5- or β1-integrin, trafficking close to the substrate-near membrane and making kiss-and-run contacts with FAs. Thus, reggie-1 in interaction with Rab11a controls Rac1 and FAK activation and coordinates the targeted recycling of α5- and β1-integrins to FAs to regulate FA formation and membrane dynamics.
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OBJECTIVE: Body mass index (BMI) may cluster in space among adults and be spatially dependent. Whether and how BMI clusters evolve over time in a population is currently unknown. We aimed to determine the spatial dependence of BMI and its 5-year evolution in a Swiss general adult urban population, taking into account the neighbourhood-level and individual-level characteristics. DESIGN: Cohort study. SETTING: Swiss general urban population. PARTICIPANTS: 6481 georeferenced individuals from the CoLaus cohort at baseline (age range 35-74 years, period=2003-2006) and 4460 at follow-up (period=2009-2012). OUTCOME MEASURES: Body weight and height were measured by trained healthcare professionals with participants standing without shoes in light indoor clothing. BMI was calculated as weight (kg) divided by height squared (m(2)). Participants were geocoded using their postal address (geographic coordinates of the place of residence). Getis-Ord Gi statistic was used to measure the spatial dependence of BMI values at baseline and its evolution at follow-up. RESULTS: BMI was not randomly distributed across the city. At baseline and at follow-up, significant clusters of high versus low BMIs were identified and remained stable during the two periods. These clusters were meaningfully attenuated after adjustment for neighbourhood-level income but not individual-level characteristics. Similar results were observed among participants who showed a significant weight gain. CONCLUSIONS: To the best of our knowledge, this is the first study to report longitudinal changes in BMI clusters in adults from a general population. Spatial clusters of high BMI persisted over a 5-year period and were mainly influenced by neighbourhood-level income.
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Objectives: To correlate the chronic stimulated electrode position on postoperative MRI with the clinical response obtained in PD patients. Material and Method: We retrospectively reviewed 14 consecutive parkinsonian patients who were selected for STN-DBS surgery. Coordinates were determined on an IR T2 MRI coronal section per pendicular to AC-PC plane 3 mm posterior to midcommissural point (MCP) and 12 mm lateral to the midline the inferior aspect of subthalamic region. A CRW stereotactic frame was used for the surgical procedure. A 3D IR T2 MRI was performed postoperatively to determine the location of the stimulated contact in each patient. The clinical results were assessed independently by the neurological team. Results: All but 2 patients had monopolar stimulation. The mean coordinates of the stimulated contacts were: AP ^ ÿ4:23G1:4, Lat ^ 1:12G0:15, Vert ^ ÿ4:1 G2:7 to the MCP. With a mean follow-up of 8 months, all stimulated patients had a significant clinical improvement (preop/postop «ON» UPDRS: 25:8G7:0= 23:3 G8:6; preop/postop «OFF» UPDRS: 50:2G11:4=26:0 G7:8), 60% of them without any antiparkinsonian drug. Conclusion: According to the stereotactic atlas of Schaltenbrand and Warren and the 3D shape of the STN, our results show that our targetting is accurate and almost all the stimulated contacts are comprised in the STN volume. This indicates that MRI is a safe, precise and reproducible procedure for targetting the STN. The location of the stimulated contact within the STN volume is a good predictor of the clinical results.
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Chlamydiales possess a minimal but functional peptidoglycan precursor biosynthetic and remodeling pathway involved in the assembly of the division septum by an atypical cytokinetic machine and cryptic or modified peptidoglycan-like structure (PGLS). How this reduced cytokinetic machine collectively coordinates the invagination of the envelope has not yet been explored in Chlamydiales. In other Gram-negative bacteria, peptidoglycan provides anchor points that connect the outer membrane to the peptidoglycan during constriction using the Pal-Tol complex. Purifying PGLS and associated proteins from the chlamydial pathogen Waddlia chondrophila, we unearthed the Pal protein as a peptidoglycan-binding protein that localizes to the chlamydial division septum along with other components of the Pal-Tol complex. Together, our PGLS characterization and peptidoglycan-binding assays support the notion that diaminopimelic acid is an important determinant recruiting Pal to the division plane to coordinate the invagination of all envelope layers with the conserved Pal-Tol complex, even during osmotically protected intracellular growth.
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Time perception is used in our day-to-day activities. While we understand quite well how our brain processes vision, touch or taste, brain mechanisms subserving time perception remain largely understudied. In this study, we extended an experiment of previous master thesis run by Tatiana Kenel-Pierre. We focused on time perception in the range of milliseconds. Previous studies have demonstrated the involvement of visual areas V1 and V5/MT in the encoding of temporal information of visual stimuli. Based on these previous findings the aim of the present study was to understand if temporal information was encoded in V1 and extrastriate area V5/MT in different spatial frames i.e., head- centered versus eye-centered. To this purpose we asked eleven healthy volunteers to perform a temporal discrimination task of visual stimuli. Stimuli were presented at 4 different spatial positions (i.e., different combinations of retinotopic and spatiotopic position). While participants were engaged in this task we interfered with the activity of the right dorsal V1 and the right V5/MT with transcranial magnetic stimulation (TMS). Our preliminary results showed that TMS over both V1 and V5/MT impaired temporal discrimination of visual stimuli presented at specific spatial coordinates. But whereas TMS over V1 impaired temporal discrimination of stimuli presented in the lower left quadrant, TMS over V5/MT affected temporal discrimination of stimuli presented at the top left quadrant. Although it is always difficult to draw conclusions from preliminary results, we could tentatively say that our data seem to suggest that both V1 and V5/MT encode visual temporal information in specific spatial frames.
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IR bands related to M-C stretchings are not diagnostically significant for the identification of carbonyl groups in the spectra of carbonyl complexes. Otherwise, the frequency, intensity and number of bands for the CO stretchings provide very useful informations about the number of CO ligands and many others structural proprieties, like the presence of bridged CO groups. We report about a relatively simple and useful method for the determination of the CO stretchings of carbonyl complexes, which considers only the bond stretching internal coordinates of the CO groups.
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The reaction of 1,2-dihydroxy-benzene (pyrocatechol) (C6H6O2) with iron oxide (Fe2O3) and sodium thiosulfate (Na2S2O3) in aqueous medium (pH 7) was investigated. Pyrocatechol suffers autoxidation and coordinates with Fe3+ in solution. The presence of S2O3(2-) in solution was fundamental to generate and stabilize the pyrocatechol oxidation products as o-semiquinones. This compound was isolated and its structure characterized using FT-IR, EPR and UV-Vis Spectroscopy as [CTA][Fe(SQ)2(Cat)]. A thermal mass loss mechanism was proposed based on Thermogravimetric Analysis (TG) to support the structural characterization.
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A simple method to obtain molecular Cartesian coordinates as a function of vibrational normal modes is presented in this work. The method does not require the definition of special matrices, like the F and G of Wilson, neither of group theory. The Eckart's conditions together with the diagonalization of kinetic and potential energy are the only required expressions. This makes the present approach appropriate to be used as a preliminary study for more advanced concepts concerning vibrational analysis. Examples are given for diatomic and triatomic molecules.