1,271 research outputs found
Powdery mildew responsive genes of resistant grapevine cultivar 'Regent'
The ascomycete Erysiphe necator causes powdery mildew disease of grapevine, a disastrous infection which is commonly defeated with multiple fungicide applications in viticulture. Breeding for natural resistance of quality grapes (Vitis vinifera) is thus a major aim of current efforts. The cultivar 'Regent' is resistant to powdery mildew due to an introgression from an American Vitis sp. resistance donor. To identify key regulatory elements in defense responses of 'Regent' we performed transcript analyses after challenging with E. necator inoculation in comparison with a susceptible grapevine. A set of genes selected from preliminary microarray hybridization results were investigated by RT-qPCR. The data indicate an important role of transcription factors MYB15, WRKY75, WRKY33, WRKY7, ethylene responsive transcription factors ERF2 and ERF5 as well as a CZF1/ZFAR transcripton factor in regulating the early defense when the fungus starts the interaction with its host by the formation of haustoria
Productivity and quality of 'Fuji Suprema' apple fruit in different rootstocks and growing conditions.
Planting density increasing with the use of dwarf rootstocks it is a fact that has changed the scenario of the pome culture in Brazil. The objective of this work was to evaluate the plant growth, productivity and fruit quality of the Fuji Suprema cultivar grafted on the rootstocks G.213 and M.9 in a new area (virgin soil) and in the replanting area of apple trees in Vacaria City in Rio Grande do Sul state, Brazil. The cultivar Fuji Suprema grafted on the rootstocks G.213 and M.9 was used, being the experiment 1 in new area and the experiment 2 in area of replanting of apple trees. In both experiments, the orchard was implanted in 2014. The spacing adopted was 4.0 m between rows and 0.9 m between plants, totaling a density of 2,777 plants per hectare. Vegetative/productive evaluations were carried out in the 2014, 2015, 2016, 2017, 2018 and 2019 harvests in commercial orchards of the company Rasip Agro Pastoril S/A. In the experiment 1, the G.213 rootstock was highlighted for the variables accumulated productivity, accumulated productive efficiency, ASTT, number of branches and scion volume. In this same experiment, the M.9 rootstock was overestimated in some crops for the variables fruit mass and pulp firmness. In the experiment 2, the G.213 rootstock was highlighted as to the accumulated productivity, accumulated productive efficiency, ASTT, number of branches and scion volume. In the 2016 crop, the rootstock M.9, stood out for the diameter and mass of fruits and soluble solids and in the 2017 harvest for pulp firmness. In order to cultivate Fuji Suprema, both in the new area and in the replanting area of apple trees, the G.213 rootstock is a new dwarf rootstock option for the southern region of Brazil
Riparian zones increase regional species richness by harboring different, not more, species
Riparian zones are habitats of critical conservation concern worldwide, as they are known to filter agricultural contaminants, buffer landscapes against erosion, and provide habitat for high numbers of species. Here we test the generality of the notion that riparian habitats harbor more species than adjacent upland habitats. Using previously published data collected from seven continents and including taxa ranging from Antarctic soil invertebrates to tropical rain forest lianas and primates, we show that riparian habitats do not harbor higher numbers of species, but rather support significantly different species pools altogether. In this way, riparian habitats increase regional (γ-) richness across the globe by >50%, on average. Thus conservation planners can easily increase the number of species protected in a regional portfolio by simply including a river within terrestrial biodiversity reserves. Our analysis also suggests numerous possible improvements for future studies of species richness gradients across riparian and upland habitats. First, <15% of the studies in our analysis included estimates of more than one taxonomic group of interest. Second, within a given taxonomic group, studies employed variable methodologies and sampling areas in pursuit of richness and turnover estimates. Future analyses of species richness patterns in watersheds should aim to include a more comprehensive suite of taxonomic groups and should measure richness at multiple spatial scales
In-flight scale/distortion calibration of the Hubble Space Telescope fixed-head star trackers
This paper describes an in-flight scale and distortion calibration procedure that has been developed for the Ball Aerospace Systems Division Fixed-Head Star Trackers (FHST's) used on the Hubble Space Telescope (HST). The FHST is a magnetically focused and deflected imaging sensor that is designed to track stars as faint as m(sub v) = 5.7 over an 8 degree by 8 degree field of view. Raw FHST position measurements are accurate to approximately 200 arcseconds, but this can be improved to 10-15 arcseconds by processing the raw measurements through calibration polynomials that correct for flat field, temperature intensity, and magnetic field effects. The coefficients for these polynomials were initially determined using ground test data. On HST the use of three FHST's is an integral part of the preliminary attitude update procedures required before the acquisition of guide stars for science observations. To this end, FHST-based attitude determination having single-axis errors no worse than 22 arcseconds (1 sigma) is required. In early 1991 it became evident that one of the HST FHST's was experiencing a significant change in its optical scale. By mid-1993 the size of this error had grown to a point that, if not corrected, it would correspond to a maximum position error on the order of 100 arcseconds. Subsequent investigations demonstrated that substantial, uncompensated cubic distortion effects had also developed, the maximum contribution to position errors from the cubic terms being on the order of 30 arcseconds. To ensure accurate FHST-based attitude updates, procedures have been developed to redetermine the FHST scale and distortion calibration coefficients based on in-flight data gathered during normal HST operations. These scale and distortion calibrations have proven very effective operationally, and procedures are in place to monitor FHST calibration changes on a continuing basis
Anthracnose susceptibility for grapevines with resistance loci to downy and powdery mildew in Southern Brazil
Anthracnose, downy and powdery mildew are the principal fungal diseases of grapes in tropical and subtropical regions. The pesticide active ingredients that control downy and powdery mildew diseases provide some protection against anthracnose attack. The release of varieties with resistance alleles to downy and powdery mildew results in less pesticide use that can increase anthracnose attack. Thus, the present work aimed to evaluate anthracnose susceptibility of genotypes with resistance loci to downy and powdery mildew under Southern Brazilian conditions. Genotype susceptibility was tested, as well as the influence of the environment (location and crop season) on increased susceptibility to anthracnose infection. To accomplish the objective, a trifactorial design was established that included 20 genotypes, two locations, and two crop seasons. Anthracnose incidence and severity were evaluated under natural infection in the field. Temperature around 16 °C and relative humidity at 84 % increased susceptibility to anthracnose infection compared to temperature around 20 °C and relative humidity at 75 %. All tested genotypes with resistance alleles to downy and powdery mildew presented symptoms of anthracnose. 'Baron', 'Cabernet Cortis' and 'Calardis Blanc' showed the least susceptibility to anthracnose, whereas 'Aromera', 'Felicia', 'Gf.2004-043-0004' and 'Gf.2004-043-0021' were the most susceptible and bore symptoms of anthracnose. Other genotypes showed variable susceptibility during the evaluation period, depending on environmental conditions. Overall, all interactions among the three tested factors were highly significant
Spin-state driven ferromagnetic and spin glass states in layered LaSrCoO
Famous for its spin-state puzzle, LaSrCoO (Co) is an intermediate
between antiferromagnetic (AFM) LaCoO (Co) and ferromagnetic
(FM) SrCoO (Co). The appearance of the Co valence state
(not present in the end compounds) is intriguing because of the spin-state
transitions associated with it. In this work, we report two magnetic
transitions in LaSrCoO: (i) a transition at T T 225 K,
from the paramagnetic state to a state with an inhomogeneous long-range
ferromagnetic (FM) order wherein finite FM clusters coexist with infinite FM
matrix in the percolation sense, and (ii) the transition to the cluster spin
glass (CSG) state at T T 8 K. Finite FM clusters (which at low
temperatures give rise to the cluster spin glass state) and infinite FM matrix
are formed due to the spin-spin interactions brought about by the
inhomogeneously distributed Co high spin (HS) and Co low spin
(LS) ions. A firm support to the presence of an unconventional (inhomogeneous)
ferromagnetic order comes from the anomalous values of the critical exponents
, and for the spontaneous magnetization, `zero-field'
magnetic susceptibility and the critical M - H isotherm, while the coexistence
of HS Co and LS Co ions is confirmed by the results of the
extended X-ray absorption fine structure spectroscopy.Comment: 18 pages, 6 figure
Superconductivity in the YIr2Si2 and LaIr2Si2 Polymorphs
We report on existence of superconductivity in YIr2Si2 and LaIr2Si2 compounds
in relation to crystal structure. The two compounds crystallize in two
structural polymorphs, both tetragonal. The high temperature polymorph (HTP)
adopts the CaBe2Ge2-structure type (space group P4/nmm) while the low
temperature polymorph (LTP) is of the ThCr2Si2 type (I4/mmm). By studying
polycrystals prepared by arc melting we have observed that the rapidly cooled
samples retain the HTP even at room temperature (RT) and below. Annealing such
samples at 900C followed by slow cooling to RT provides the LTP. Both, the HTP
and LTP were subsequently studied with respect to magnetism and
superconductivity by electrical resistivity, magnetization, AC susceptibility
and specific heat measurements. The HTP and LTP of both compounds respectively,
behave as Pauli paramagnets. Superconductivity has been found exclusively in
the HTP of both compounds below Tsc (= 2.52 K in YIr2Si2 and 1.24 K in
LaIr2Si2). The relations of magnetism and superconductivity with the electronic
and crystal structure are discussed with comparing experimental data with the
results of first principles electronic structure calculations
Metabolic fate, mass spectral fragmentation, detectability, and differentiation in urine of the benzofuran designer drugs 6-APB and 6-MAPB in comparison to their 5-isomers using GC-MS and LC-(HR)-MSn techniques
The number of so-called new psychoactive substances (NPS) is still increasing by modification of the chemical structure of known (scheduled) drugs. As analogues of amphetamines, 2-aminopropyl-benzofurans were sold. They were consumed because of their euphoric and empathogenic effects. After the 5-(2-aminopropyl)benzofurans, the 6-(2-aminopropyl)benzofuran isomers appeared. Thus, the question arose whether the metabolic fate, the mass spectral fragmentation, and the detectability in urine are comparable or different and how an intake can be differentiated. In the present study, 6-(2-aminopropyl)benzofuran (6-APB) and its N-methyl derivative 6-MAPB (N-methyl-6-(2-aminopropyl)benzofuran) were investigated to answer these questions. The metabolites of both drugs were identified in rat urine and human liver preparations using GC-MS and/or liquid chromatography-high resolution-mass spectrometry (LC-HR-MSn). Besides the parent drug, the main metabolite of 6-APB was 4-carboxymethyl-3-hydroxy amphetamine and the main metabolites of 6-MAPB were 6-APB (N-demethyl metabolite) and 4-carboxymethyl-3-hydroxy methamphetamine. The cytochrome P450 (CYP) isoenzymes involved in the 6-MAPB N-demethylation were CYP1A2, CYP2D6, and CYP3A4. An intake of a common users’ dose of 6-APB or 6-MAPB could be confirmed in rat urine using the authors’ GC-MS and the LC-MSn standard urine screening approaches with the corresponding parent drugs as major target allowing their differentiation. Furthermore, a differentiation of 6-APB and 6-MAPB in urine from their positional isomers 5-APB and 5-MAPB was successfully performed after solid phase extraction and heptafluorobutyrylation by GC-MS via their retention times
Optogenetics and deep brain stimulation neurotechnologies
Brain neural network is composed of densely packed, intricately wired neurons whose activity patterns ultimately give rise to every behavior, thought, or emotion that we experience. Over the past decade, a novel neurotechnique, optogenetics that combines light and genetic methods to control or monitor neural activity patterns, has proven to be revolutionary in understanding the functional role of specific neural circuits. We here briefly describe recent advance in optogenetics and compare optogenetics with deep brain stimulation technology that holds the promise for treating many neurological and psychiatric disorders
Possible pseudogap behavior of electron doped high-temperature superconductors
We have measured the low-energy quasiparticle excitation spectrum of the
electron doped high-temperature superconductors (HTS) Nd(1.85)Ce(0.15)CuO(4-y)
and Pr(1.85)Ce(0.15)CuO(4-y) as a function of temperature and applied magnetic
field using tunneling spectroscopy. At zero magnetic field, for these optimum
doped samples no excitation gap is observed in the tunneling spectra above the
transition temperature Tc. In contrast, below Tc for applied magnetic fields
well above the resistively determined upper critical field, a clear excitation
gap at the Fermi level is found which is comparable to the superconducting
energy gap below Tc. Possible interpretations of this observation are the
existence of a normal state pseudogap in the electron doped HTS or the
existence of a spatially non-uniform superconducting state.Comment: 4 pages, 4 ps-figures included, to be published in Phys. Rev. B,
Rapid Com
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