A survey of potential vectors of apricot chlorotic leaf roll

A comparative survey was done in leafhopper populations captured in apricot orchards in two areas of Valencia, one with considerable natural spread of apricot chlorotic leaf roll (ACLR), and the other where such natural spread is virtually nonexistent. An identification of the leafhopper species found in the first and in the second area suggest that Neoaliturus haematoceps and/or Neoaliturus fertestratus are the potential vectors of ACLR, at least under the conditions of Valencia province. Psammotettix striatus and Austroagallia sinuata are potential secondary vextors of ACLR.

Morphological and functional variability in the root system of Quercus ilex L. subject to confinement: consequences for afforestation

We examined root morphological and functional differences caused by restrictions imposed to vertical growth in the root system of holm oak (Quercus ilex L.) seedlings to assess the consequences of using nursery containers in the development of a confined root system for this species. Thus, root morphological, topological and functional parameters, including hydraulic conductance per leaf unit surface area (K $_{\rm RL})$, were investigated in one-year seedlings cultivated in three PVC tubes differing in length (20, 60 and 100 cm). Longer tubes showed greater projected root area, root volume, total and fine root lengths, specific root length (SRL) and K$_{\rm RL}$ values than did shorter tubes. On the other hand, the length of coarse roots (diameter > 4.5 mm) and the average root diameter were greater in shorter tubes. The strong positive correlation found between K$_{\rm RL}$ and SRL (r=+0.69; P<0.001) indicated that root thickness was inversely related to water flow through the root system. We concluded that root systems developed in longer tubes are more efficient for plant water uptake and, therefore, changes in root pattern produced in standard forest containers (i.e. about 20 cm length) may in fact prevent a proper establishment of the holm oak in the field, particularly in xeric environments.

Surface functionalization of alumina ceramic foams with organic ligands.

Different anchoring groups have been studied with the aim of covalently binding organic linkers to the surface of alumina ceramic foams. The results suggested that a higher degree of functionalization was achieved with a pyrogallol derivative - as compared to its catechol analogue - based on the XPS analysis of the ceramic surface. The conjugation of organic ligands to the surface of these alumina materials was corroborated by DNP-MAS NMR measurements.

Quantification of the relation between surface morphodynamics and subsurface sedimentological product in sandy braided rivers

This study uses digital elevation models and ground-penetrating radar to quantify the relation between the surface morphodynamics and subsurface sedimentology in the sandy braided South Saskatchewan River, Canada. A unique aspect of the methodology is that both digital elevation model and ground-penetrating radar data were collected from the same locations in 2004, 2005, 2006 and 2007, thus enabling the surface morphodynamics to be tied explicitly to the associated evolving depositional product. The occurrence of a large flood in 2005 also allowed the influence of discharge to be assessed with respect to the processproduct relationship. The data demonstrate that the morphology of the study reach evolved even during modest discharges, but more extensive erosion was caused by the large flood. In addition, the study reach was dominated by compound bars before the flood, but switched to being dominated by unit bars during and after the flood. The extent to which the subsurface deposits (the product') were modified by the surface morphodynamics (the process') was quantified using the changes in radar-facies recorded in sequential ground-penetrating radar surveys. These surveys reveal that during the large flood there was an increase in the proportion of facies associated with bar margin accretion and larger dunes. In subsequent years, these facies became truncated and replaced with facies associated with smaller dune sets. This analysis shows that unit bars generally become truncated more laterally than vertically and, thus, they lose the high-angle bar margin deposits and smaller scale bar-top deposits. In general, the only fragments that remain of the unit bars are dune sets, thus making identification of the original unit barform problematic. This novel data set has implications for what may ultimately become preserved in the rock record.

Innovative LIDAR 3D dynamic measurement system to estimate fruit-tree leaf area

In this work, a LIDAR-based 3D Dynamic Measurement System is presented and evaluated for the geometric characterization of tree crops. Using this measurement system, trees were scanned from two opposing sides to obtain two three-dimensional point clouds. After registration of the point clouds, a simple and easily obtainable parameter is the number of impacts received by the scanned vegetation. The work in this study is based on the hypothesis of the existence of a linear relationship between the number of impacts of the LIDAR sensor laser beam on the vegetation and the tree leaf area. Tests performed under laboratory conditions using an ornamental tree and, subsequently, in a pear tree orchard demonstrate the correct operation of the measurement system presented in this paper. The results from both the laboratory and field tests confirm the initial hypothesis and the 3D Dynamic Measurement System is validated in field operation. This opens the door to new lines of research centred on the geometric characterization of tree crops in the field of agriculture and, more specifically, in precision fruit growing.

Modelling leaf development in Oxalis latifolia

This study was carried to develop functions that could explain the growth of Oxalis latifolia, in both early stages and throughout the season, contributing to the improvement of its cultural control. Bulbs of the Cornwall form of O. latifolia were buried at 1 and 8 cm in March 1999 and 2000. Samples were destructive at fixed times, and at each time the corresponding BBCH scale codes as well as the absolute number of growing and adult leaves were noted. Using the absolute number of adult leaves (transformed to percentages), a Gaussian curve of three parameters that explains the growth during the season (R2=0.9355) was developed. The BBCH scale permitted the fit of two regression lines that were accurately adjusted for each burial depth (R2=0.9969 and R2=0.9930 respectively for 1 and 8 cm). The best moment for an early defoliation in Northern Spain could be calculated with these regression lines, and was found to be the second week of May. In addition, it was observed that a burial depth of 8 cm does not affect the growing pattern of the weed, but it affects the number of leaves they produce, which decreases to less than a half of those produced at 1 cm.

Estudio de algunas características de las plantas en variedad de peral y su relación con la incidencia de la psila (Cacopsylla Pyri (L.) Hemiptera: Psyllidae)

Se estudian algunas de las características varietales del peral que pueden influir sobre la instalación y desarrollo de las poblaciones de Cacopsylla pyri (L.). El estudio se realizó en una finca de la Estación Experimental de Lleida en Gimenells, para las variedades Blanquilla y Conference. Los parámetros medidos en la planta fueron: el incremento del perímetro del tronco, la densidad de lamburdas, la superficie foliar, el contenido en clorofila, el contenido en agua y el grosor de la hoja. Para estimar la densidad de poblacion del insecto, se realizaron recuentos de los estados inmaduros de C. pyri en lamburdas durante el invierno y en brotes tiernos durante el periodo vegetativo en los años 2000 y 2001. Se han observado diferencias significativas entre las dos variedades en cuanto a las características de la planta estudiadas y la incidencia de C. pyri. La incidencia de la psila es mayor en la variedad Blanquilla, variedad más vigorosa, con mayor superficie foliar, hojas más delgadas y con menor contenido en clorofila que la variedad Conference.

Effect of humic substances and weather conditions on leaf biochemical changes of fertigated guava tree, during orchard establishment

In São Francisco Valley, Northeast Brazil, humic substances have been used by growers in fertigated fruit crops, due to its improvements on soil conditions and in plant nutrient uptake, metabolism and growth, reported from different growing places and crops. Nevertheless, little information about plant response to humic substance usage for local soil, weather and cropping system conditions is known. Hence, the metabolic response of guava tree during the orchard establishment to fertigation with humic substances and its correlation to the weather conditions were evaluated in Petrolina, State of Pernambuco. The treatments were manure application in soil combined with mineral fertilizers and humic substances applied through water of irrigation. The results showed that the fertigation treatments and plant age did not present conclusive effects in guava leaf contents of carbohydrates, proteins and amino acids. On the other side, the leaf contents of these compounds were influenced by the weather conditions.

Discriminating crop, weeds and soil surface with a terrestrial LIDAR sensor

In this study, the evaluation of the accuracy and performance of a light detection and ranging (LIDAR) sensor for vegetation using distance and reflection measurements aiming to detect and discriminate maize plants and weeds from soil surface was done. The study continues a previous work carried out in a maize field in Spain with a LIDAR sensor using exclusively one index, the height profile. The current system uses a combination of the two mentioned indexes. The experiment was carried out in a maize field at growth stage 12–14, at 16 different locations selected to represent the widest possible density of three weeds: Echinochloa crus-galli (L.) P.Beauv., Lamium purpureum L., Galium aparine L.and Veronica persica Poir.. A terrestrial LIDAR sensor was mounted on a tripod pointing to the inter-row area, with its horizontal axis and the field of view pointing vertically downwards to the ground, scanning a vertical plane with the potential presence of vegetation. Immediately after the LIDAR data acquisition (distances and reflection measurements), actual heights of plants were estimated using an appropriate methodology. For that purpose, digital images were taken of each sampled area. Data showed a high correlation between LIDAR measured height and actual plant heights (R2 = 0.75). Binary logistic regression between weed presence/absence and the sensor readings (LIDAR height and reflection values) was used to validate the accuracy of the sensor. This permitted the discrimination of vegetation from the ground with an accuracy of up to 95%. In addition, a Canonical Discrimination Analysis (CDA) was able to discriminate mostly between soil and vegetation and, to a far lesser extent, between crop and weeds. The studied methodology arises as a good system for weed detection, which in combination with other principles, such as vision-based technologies, could improve the efficiency and accuracy of herbicide spraying.

Short communication.Wood identification based on their common name and their transversal surface anatomy. Application to the batch from the expedition of Ruiz and Pavon

Aim of study: To identify species of wood samples based on common names and anatomical analyses of their transversal surfaces (without microscopic preparations). Area of study: Spain and South America Material and methods: The test was carried out on a batch of 15 lumber samples deposited in the Royal Botanical Garden in Madrid, from the expedition by Ruiz and Pavon (1777-1811). The first stage of the methodology is to search and to make a critical analysis of the databases which list common nomenclature along with scientific nomenclature. A geographic filter was then applied to the information resulting from the samples with a more restricted distribution. Finally an anatomical verification was carried out with a pocket microscope with a magnification of x40, equipped with a 50 micrometers resolution scale. Main results: The identification of the wood based exclusively on the common name is not useful due to the high number of alternative possibilities (14 for “naranjo”, 10 for “ébano”, etc.). The common name of one of the samples (“huachapelí mulato”) enabled the geographic origin of the samples to be accurately located to the shipyard area in Guayaquil (Ecuador). Given that Ruiz y Pavon did not travel to Ecuador, the specimens must have been obtained by Tafalla. It was possible to determine correctly 67% of the lumber samples from the batch. In 17% of the cases the methodology did not provide a reliable identification. Research highlights: It was possible to determine correctly 67% of the lumber samples from the batch and their geographic provenance. The identification of the wood based exclusively on the common name is not useful.

Recruitment of Matrix Metalloproteinase-9 (MMP-9) to the Fibroblast Cell Surface by Lysyl Hydroxylase 3 (LH3) Triggers Transforming Growth Factor-β (TGF-β) Activation and Fibroblast Differentiation.

Solid tumor growth triggers a wound healing response. Similar to wound healing, fibroblasts in the tumor stroma differentiate into myofibroblasts (also referred to as cancer-associated fibroblasts) primarily, but not exclusively, in response to transforming growth factor-β (TGF-β). Myofibroblasts in turn enhance tumor progression by remodeling the stroma. Among proteases implicated in stroma remodeling, matrix metalloproteinases (MMPs), including MMP-9, play a prominent role. Recent evidence indicates that MMP-9 recruitment to the tumor cell surface enhances tumor growth and invasion. In the present work, we addressed the potential relevance of MMP-9 recruitment to and activity at the surface of fibroblasts. We show that recruitment of MMP-9 to the fibroblast cell surface occurs through its fibronectin-like (FN) domain and that the molecule responsible for the recruitment is lysyl hydroxylase 3 (LH3). Functional assays suggest that both pro- and active MMP-9 trigger α-smooth muscle actin expression in cultured fibroblasts, reflecting myofibroblast differentiation, possibly as a result of TGF-β activation. Moreover, the recombinant FN domain inhibited both MMP-9-induced TGF-β activation and α-smooth muscle actin expression by displacing MMP-9 from the fibroblast cell surface. Together our results uncover LH3 as a new docking receptor of MMP-9 on the fibroblast cell surface and demonstrate that the MMP-9 FN domain is essential for the interaction. They also show that the recombinant FN domain inhibits MMP-9-induced TGF-β activation and fibroblast differentiation, providing a potentially attractive therapeutic reagent toward attenuating tumor progression where MMP-9 activity is strongly implicated.

The membrane-permeable calmodulin inhibitors (W-7/W-13) bind to membranes changing the electrostatic surface potential. Dual effect of W-13 on EGFR activation

Membrane-permeable calmodulin inhibitors, such as the napthalenesulfonamide derivatives W-7/W-13, trifluoperazine, and calmidazolium, are used widely to investigate the role of calcium/calmodulin (Ca2+/CaM) in living cells. If two chemically different inhibitors (e.g. W-7 and trifluoperazine) produce similar effects, investigators often assume the effects are due to CaM inhibition. Zeta potential measurements, however, show that these amphipathic weak bases bind to phospholipid vesicles at the same concentrations as they inhibit Ca 2 /CaM; this suggests that they also bind to the inner leaflet of the plasma membrane, reducing its negative electrostatic surface potential. This change will cause electrostatically bound clusters of basic residues on peripheral (e.g. Src and K-Ras4B) and integral (e.g. epidermal growth factor receptor (EGFR)) proteins to translocate from the membrane to the cytoplasm. We measured inhibitor-mediated translocation of a simple basic peptide corresponding to the calmodulin-binding juxtamembrane region of the EGFR on model membranes; W-7/W-13 causes translocation of this peptide from membrane to solution, suggesting that caution must be exercised when interpreting the results obtained with these inhibitors in living cells. We present evidence that they exert dual effects on autophosphorylation of EGFR;W-13 inhibits epidermal growth factordependent EGFR autophosphorylation under different experimental conditions, but in the absence of epidermal growth factor, W-13 stimulates autophosphorylation of the receptor in four different cell types. Our interpretation is that the former effect is due toW-13inhibition of Ca 2 /CaM, but thelatter results could be due to binding of W-13 to the plasma membrane.

Controlling the spin of metal atoms adsorbed on oxide surfaces: Ni on regular and defective sites of the MgO(001) surface

We have analyzed the relative energy of nonmagnetic and magnetic low-lying electronic states of Ni atoms adsorbed on regular and defective sites of the MgO(001) surface. To this end cluster and periodic surface models are used within density functional theory. For Ni atoms adsorbed on oxygen vacancies at low coverage, the interaction energy between the metal and the support is much larger than on regular sites. Strong bonding results in a diamagnetic adsorbed species and the energy required to reach the high-spin state increases. Moreover, a correlation appears between the low-spin to high-spin energy difference and the interaction energy hypothesizing that it is possible to prepare the surface to tune the high-spin to low-spin energy difference. Magnetic properties of adsorbed thin films obtained upon increasing coverage are more difficult to interpret. This is because the metallic bond is readily formed and dominates over the effect of the atoms directly bound to the vacancy.

Paper Surface Image Processing for Roughness Quality Measurement

Diplomityössä on käsitelty paperin pinnankarkeuden mittausta, joka on keskeisimpiä ongelmia paperimateriaalien tutkimuksessa. Paperiteollisuudessa käytettävät mittausmenetelmät sisältävät monia haittapuolia kuten esimerkiksi epätarkkuus ja yhteensopimattomuus sileiden papereiden mittauksissa, sekä suuret vaatimukset laboratorio-olosuhteille ja menetelmien hitaus. Työssä on tutkittu optiseen sirontaan perustuvia menetelmiä pinnankarkeuden määrittämisessä. Konenäköä ja kuvan-käsittelytekniikoita tutkittiin karkeilla paperipinnoilla. Tutkimuksessa käytetyt algoritmit on tehty Matlab® ohjelmalle. Saadut tulokset osoittavat mahdollisuuden pinnankarkeuden mittaamiseen kuvauksen avulla. Parhaimman tuloksen perinteisen ja kuvausmenetelmän välillä antoi fraktaaliulottuvuuteen perustuva menetelmä.