bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical energy gradient in variational calculations of the two lowest P3 states of the carbon atom with explicitly correlated Gaussian basis functions
Authors: Sharkey Keeper L. , Bubin Sergiy , Adamowicz Ludwik
Published: May 2010

Variational calculations of ground and excited bound states on atomic and molecular systems performed with basis functions that explicitly depend on the interparticle distances can generate very accurate results provided that the basis function parameters are thoroughly optimized by the minimization of the energy. In this work we have derived the algorithm for the gradient of the energy determined with respect to the nonlinear exponential parameters of explicitly correlated Gaussian functions used in calculating n-electron atomic systems with two p-electrons and (n−2) s-electrons. The atomic Hamiltonian we used was obtained by rigorously separating out the kinetic energy of the center of mass motion from the laboratory-frame Hamiltonian and explicitly depends on the finite mass of the nucleus. The advantage of having the gradient available in the variational minimization of the energy is demonstrated in the calculations of the ground and the first excited P3 state of the carbon atom. For the former the lowest energy upper bound ever obtained is reported.
Infrared spectroscopy of the organic monolayer sandwiched between a Hg electrode and a Si substrate
Authors: Furuhashi Masayuki , Yoshinobu Jun
Published: May 2010

We have successfully observed the vibrational spectra of organic monolayers sandwiched between a liquid Hg electrode and a Si substrate by means of a newly developed reflection absorption (RA) device. The vibrational spectra of organic monolayers between two electrodes can be observed under a certain bias voltage. The monolayers were fabricated by the reaction of hydrogen-terminated Si(111) with 1-octadecene. A metal/insulator/semiconductor structure was prepared using liquid Hg as a metal electrode and the organic monolayer as an insulator. Infrared (IR) light entered from the Si substrate side with an incident angle of 75°. The reflected IR light from the metallic Hg was detected by a mercury-cadmium-telluride detector. We obtained RA spectra using a bare H–Si(111) substrate as a reference. The absorbance of the RA spectrum was comparable with that of the transmission spectrum for the octadecyl-terminated Si(111) without Hg. The C–H stretching modes in the CH2 group show blueshifts, and the C–H antisymmetric stretching modes in the CH3 are broadened in comparison with the transmission spectrum. Under a certain bias voltage, we observed changes in band shape. We concluded that the variation was due to the temperature increase by resistive heating of the substrate.
Microcontroller-based binary integrator for millimeter-wave radar experiments
Authors: Eskelinen Pekka , Ruoskanen Jukka , Peltonen Jouni
Published: May 2010

An easily on-site reconfigurable multiple binary integrator for millimeter radar experiments has been constructed of static random access memories, an eight bit microcontroller, and high speed video operational amplifiers. The design uses a raw comparator path and two adjustable m-out-of-n chains in a wired-OR configuration. Standard high speed memories allow the use of pulse widths below 100 ns. For eight pulse repetition intervals it gives a maximum improvement of 6.6 dB for stationary low-level target echoes. The doubled configuration enhances the capability against fluctuating targets. Because of the raw comparator path, also single return pulses of relatively high amplitude are processed.
Threshold-variation-enhanced adaptability of response in a nanowire field-effect transistor network
Authors: Kasai Seiya , Miura Kensuke , Shiratori Yuta
Published: May 2010

Stochastic resonance in a summing network with varied thresholds was investigated using GaAs-based etched nanowire field-effect transistors having different threshold voltages. The network’s response adapted to input offset fluctuations in the range of the threshold voltage variation and the network could detect a weak signal without any adjustment of the input offset or the addition of high noise. The observed adaptability resulted from a widened dynamic range of the system due to signal decomposition and reconstruction by multiple thresholds together with the output summation process.
Simulation of magnetization switching by electric-field manipulation of magnetic anisotropy
Authors: Chiba D. , Nakatani Y. , Matsukura F. , Ohno H.
Published: May 2010

Electrical anisotropy modulation was recently observed in ferromagnetic semiconductors and metals. The authors have investigated magnetization switching through magnetic anisotropy modulation induced by external electric field by means of simulation. Macrospin simulation using Landau–Lifshitz–Gilbert equation shows that switching is possible by controlling magnetic anisotropy for appropriate sets of parameters. The condition for quasistatic magnetization switching is also presented, in which magnetization direction is determined to minimize the magnetic free energy.
Group-II acceptors in wurtzite AlN: A screened hybrid density functional study
Authors: Szabó Áron , Son Ngyen Tien , Janzén Erik , Gali Adam
Published: May 2010

We systematically studied the group-II acceptors in wurtzite AlN by screened hybrid density functional calculations. We show that the shallowest isolated group-II substitutional defect is Mg, while codoping of Mg and O may yield even shallower acceptor level.
Charge detrapping and dielectric breakdown of nanocrystalline zinc oxide embedded zirconium-doped hafnium oxide high-k dielectrics for nonvolatile memories
Authors: Yang Chia-Han , Kuo Yue , Lin Chen-Han
Published: May 2010

Charge detrapping and dielectric breakdown phenomena of the nanocrystalline zinc oxide embedded zirconium-doped hafnium oxide high-k dielectric have been investigated. Charges were loosely or strongly retained at the nanocrystal sites which were saturated above a certain stress voltage. From the polarity change of the relaxation current, it was confirmed that the high-k part of the dielectric film was broken under a high gate bias voltage condition while the nanocrystals still retained charges. These charges were gradually released. These unique characteristics are important to the performance and reliability of the memory device.
Structural defects working as active oxygen-reduction sites in partially oxidized Ta-carbonitride core-shell particles probed by using surface-sensitive conversion-electron-yield x-ray absorption spectroscopy
Authors: Imai Hideto , Matsumoto Masashi , Miyazaki Takashi , Fujieda Shinji , Ishihara Akimitsu , Tamura Motoko , Ota Ken-ichiro
Published: May 2010

We analyzed the local structure of the surface Ta-oxide phase of TaCN/Ta2O5 core-shell particles that have a high oxygen reduction activity by using surface-sensitive conversion-electron-yield x-ray absorption spectroscopy, suppressing the contribution from the TaCN cores. The radial structure analysis revealed that the catalytically-active Ta2O5 phase in the TaCN/Ta2O5 particle surface contains oxygen-vacancy defects with shorter Ta–O bonds leading to the slight expansion of the first Ta–O shell. Such oxygen defects are likely responsible for the oxygen reduction capability by creating electronically favorable oxygen adsorption sites and electron conduction pathways.
Sunlight exposure caused yellowing and increased mineral content in wool
Authors: Fleet M. R. , Millington K. R. , King A. L.
Published: May 2010

This study determines how levels of various trace metals in wool and the colour of the fibre change as a result of sunlight exposure and treatment with chelating compounds during wool growth. Twenty-four yearling Merino sheep were clipped on the shoulders and rumps and fitted with sheep coats modified with transparent patches. Patches over the shoulder wool (one per sheep) were either polyethylene (PE) that transmits ultraviolet light or polyvinyl chloride (PVC) that excludes ultraviolet light. The rump wool on each sheep was treated either with a copper chelator treatment (kojic acid or methyl gentisate in aqueous alcohol) or aqueous alcohol only. For 12 of the sheep the rumps were exposed to sunlight through PE patches while rump wool on the other sheep was covered by the sheep coat. Wool was harvested after 11 weeks’ growth with yellowness (Y-Z) and individual mineral contents measured using the same clean wool sample. Sunlight exposure through PE patches caused a mean increase in Y-Z to 9.1 (shoulder) or 9.5–10.1 (rump) from a base level of 7.1–7.2 (shoulder) or 7.0–7.6 (rump) in wool protected by the sheep coat. In contrast, there was no significant change in Y-Z for the PVC patch (shoulder). Therefore, it appears that ultraviolet light damage caused the increased Y-Z. Most of the trace metals analysed increased in the shoulder wool exposed to sunlight but the paired differences for PVC were lower than PE. It appears that changes in fibre caused by sunlight exposure (especially ultraviolet light) facilitate adsorption of minerals from the environment, including the animal’s own suint. Application of the chelating compounds to the rump wool caused pronounced yellowing of the wool with Y-Z increase being most pronounced for kojic acid. Copper levels in the wool were reduced by kojic acid and methyl gentisate while calcium levels were increased by kojic acid and reduced by methyl gentisate. It is not clear from these findings whether minerals and copper in particular contribute to yellowing of wool. However, the different effects of sunlight and chelation on mineral contents in wool shown may well relate to alternative mechanisms of discoloration (i.e. photoyellowing versus bacterial).
Development of profitable milk production systems for northern Australia: a field assessment of the productivity of five potential farming systems using farmlets
Authors: Chataway R. G. , Walker R. G. , Callow M. N.
Published: May 2010

Farmlets, each of 20 cows, were established to field test five milk production systems and provide a learning platform for farmers and researchers in a subtropical environment. The systems were developed through desktop modelling and industry consultation in response to the need for substantial increases in farm milk production following deregulation of the industry. Four of the systems were based on grazing and the continued use of existing farmland resource bases, whereas the fifth comprised a feedlot and associated forage base developed as a greenfield site.
The field evaluation was conducted over 4 years under more adverse environmental conditions than anticipated with below average rainfall and restrictions on irrigation. For the grazed systems, mean annual milk yield per cow ranged from 6330 kg/year (1.9 cows/ha) for a herd based on rain-grown tropical pastures to 7617 kg/year (3.0 cows/ha) where animals were based on temperate and tropical irrigated forages. For the feedlot herd, production of 9460 kg/cow.year (4.3 cows/ha of forage base) was achieved. For all herds, the level of production achieved required annual inputs of concentrates of ~3 t DM/animal and purchased conserved fodder from 0.3 to 1.5 t DM/animal. This level of supplementary feeding made a major contribution to total farm nutrient inputs, contributing 50% or more of the nitrogen, phosphorus and potassium entering the farming system, and presents challenges to the management of manure and urine that results from the higher stocking rates enabled.
Mean annual milk production for the five systems ranged from 88 to 105% of that predicted by the desktop modelling. This level of agreement for the grazed systems was achieved with minimal overall change in predicted feed inputs; however, the feedlot system required a substantial increase in inputs over those predicted. Reproductive performance for all systems was poorer than anticipated, particularly over the summer mating period.
We conclude that the desktop model, developed as a rapid response to assist farmers modify their current farming systems, provided a reasonable prediction of inputs required and milk production. Further model development would need to consider more closely climate variability, the limitations summer temperatures place on reproductive success and the feed requirements of feedlot herds.
Low rates of phosphorus fertiliser applied strategically throughout the growing season under rain-fed conditions did not affect dry matter production of perennial ryegrass (Lolium perenne L.)
Authors: Burkitt L. L. , Donaghy D. J. , Smethurst P. J.
Published: May 2010

Pasture is the cheapest source of feed for dairy cows, therefore, dairy pastures in Australia are intensively managed to maximise milk production and profits. Although soil testing commonly suggests that soils used for dairy pasture production have adequate supplies of phosphorus (P), many Australian dairy farmers still apply fertiliser P, often by applying smaller rates more frequently throughout the year. This study was designed to test the hypotheses that more frequent, but lower rates of P fertiliser applied strategically throughout the growing season have no effect on dry matter production and P concentration in perennial ryegrass (Lolium perenne L.), when soil extractable P concentrations are above the critical value reported in the literature. Three field sites were established on rain-fed dairy pasture soils ranging in P sorption capacity and with adequate soil P concentrations for maximising pasture production. Results showed that applied P fertiliser had no effect on pasture production across the 3 sites (P > 0.05), regardless of rate or the season in which the P was applied, confirming that no P fertiliser is required when soil extractable P concentrations are adequate. This finding challenges the viability of the current industry practice. In addition, applying P fertiliser as a single annual application in summer did not compromise pasture production at any of the 3 sites (P > 0.05), which supports the current environmental recommendations of applying P during drier conditions, when the risk of surface P runoff is generally lower. The current results also demonstrate that the short-term cessation of P fertiliser application may be a viable management option, as a minimal reduction in pasture production was measured over the experimental period.
Variation in salinity tolerance, early shoot mass and shoot ion concentrations within Lotus tenuis: towards a perennial pasture legume for saline land
Authors: Teakle N. L. , Snell A. , Real D. , Barrett-Lennard E. G. , Colmer T. D.
Published: May 2010

Perennial legumes are needed for productive pastures in saline areas. We evaluated 40 lines of Lotus tenuis for tolerance to salinity at both germination and vegetative growth stages. Salt tolerance during the early vegetative stage was assessed in a sand-tank experiment with NaCl concentrations of 0–450 mm NaCl for 5 weeks. Most L. tenuis lines were more salt tolerant and had at least 50% lower shoot Na+ plus Cl– (% dry mass (DM)) compared with some other common pasture legumes, Medicago sativa, M. polymorpha and Trifolium subterraneum. Within L. tenuis significant variation in salt tolerance was found, with C50 values (concentrations of NaCl that decreased shoot dry matter to 50% of control) ranging from ~100 to 320 mm. Shoot concentrations of Cl–, Na+ and K+ did not always correlate with salt tolerance; some tolerant lines had low shoot Na+ and Cl– (and thus better nutritive value), while others tolerated high shoot Na+ and Cl–. We also found variation within L. tenuis for salt tolerance of seeds, with lines ranging from 0 to 70% germination after recovery from a prior exposure to 800 mm NaCl for 15 days. There was no relationship between salinity tolerance of scarified seeds and subsequent growth of seedlings; therefore, testing of seeds alone would not be an appropriate screening method for salt tolerance in L. tenuis. This study of 40 L. tenuis lines has shown significant genetic variation for salt tolerance within this species, and we have identified key lines with potential to be productive in saltland pasture systems.
Insulin/IGF-1 signaling mutants reprogram ER stress response regulators to promote longevity
Authors: Henis-Korenblit Sivan , Zhang Peichuan , Hansen Malene , McCormick Mark , Lee Seung-Jae , Cary Michael , Kenyon Cynthia
Published: May 2010

When unfolded proteins accumulate in the endoplasmic reticulum (ER), the unfolded protein response is activated. This ER stress response restores ER homeostasis by coordinating processes that decrease translation, degrade misfolded proteins, and increase the levels of ER-resident chaperones. Ribonuclease inositol-requiring protein–1 (IRE-1), an endoribonuclease that mediates unconventional splicing, and its target, the XBP-1 transcription factor, are key mediators of the unfolded protein response. In this study, we show that in
Caenorhabditis elegans
insulin/IGF-1 pathway mutants, IRE-1 and XBP-1 promote lifespan extension and enhance resistance to ER stress. We show that these effects are not achieved simply by increasing the level of spliced
xbp-1
mRNA and expression of XBP-1’s normal target genes. Instead, in insulin/IGF-1 pathway mutants, XBP-1 collaborates with DAF-16, a FOXO-transcription factor that is activated in these mutants, to enhance ER stress resistance and to activate new genes that promote longevity.
Unregulated ARF6 Activation in Epithelial Cysts Generates Hyperactive Signaling Endosomes and Disrupts Morphogenesis
Authors: Tushir Jogender S. , Clancy James , Warren Andrew , Wrobel Carolyn , Brugge Joan S. , D'Souza-Schorey Crislyn
Published: May 2010

Tumor development in glandular tissues is associated with structural alterations in the hollow ducts and spherical structures that comprise such tissues. We describe a signaling axis involving sustained activation of the GTP-binding protein, ARF6, that provokes dramatic changes in the organization of epithelial cysts, reminiscent of tumorigenic glandular phenotypes. In reconstituted basement membrane cultures of renal epithelial cysts, enhanced ARF6 activation induces the formation of cell-filled glandular structures with multiple lumens and disassembled cadherin-based cell–cell contacts. All of these alterations are accompanied by growth factor receptor internalization into signaling endosomes and reversed by blocking ARF6 activation or receptor endocytosis. Receptor localization in signaling endosomes results in hyperactive extracellular signal-regulated kinase signaling leading to Bcl-2 stabilization and aberrant cysts. Similarly, formation of hyperproliferative and disorganized mammary acini induced by chronic stimulation of colony-stimulating factor 1 receptor is coupled to endogenous ARF6 activation and constitutive receptor internalization and is reversed by ARF6 inhibition. These findings identify a previously unrecognized link between ARF6-regulated receptor internalization and events that drive dramatic alterations in cyst morphogenesis providing new mechanistic insight into the molecular processes that can promote epithelial glandular disruption.
What is a Contradiction?
Authors: Grim Patrick
Published: May 2010

Definitions drawn from the literature show that the central notion of contradiction is neither simple nor agreed upon. Contradiction has been outlined ontologically, semantically, syntactically, and in terms of assertion and denial; interpretations of the Law of Non-Contradiction (LNC) and of Dialetheism will vary accordingly. Does the range of different concepts of contradiction allow at least some easy cases in deciding for or against Dialetheism or the LNC? Even that attempt, it turns out, quickly faces a crucial impasse regarding exclusionary negation, here outlined in terms of ‘not’. This chapter explores possible responses to the impasse, on both sides, but offers no logically coercive solution.
True and False—As If
Authors: Beall JC
Published: May 2010

This chapter advances a version of ‘deflated dialetheism’, a dialetheic truth theory motivated by a ‘deflationary’ conception of truth. In short: truth is an expressive device that we have constructed for practical purposes; it is also an inconsistent device (some sentences are true and not), but such inconsistency does not get in the way of the job ‘true’ was brought in to do. After presenting the target view, objections are addressed.
‘To Pee and not to Pee?’ Could That Be the Question? (Further Reflections of The Dog)
Authors: Garfield Jay
Published: May 2010

Priest's LP is formulated with truth value gaps, but no gluts. The Dog argues on epistemological grounds that a paraconsistent logic with truth value gaps as well as gluts is better than one with gluts alone, and shows how this can be achieved with minimal fuss.
An Anti-Realist Critique of Dialetheism
Authors: Tennant Neil
Published: May 2010

This chapter criticizes dialetheism from the point of view of an anti-realist with sympathy for relevantism in logical reasoning. It argues that the view that there are true contradictions suffers both from an improper understanding of the interrelations among absurdity, contrariety, falsity, and negation, and from an incorrect diagnosis of what gives rise to the well-known contradictions in semantics and mathematical foundations. Anti-realism emerges as a better reflective equilibrium than dialetheism in confrontation with all these phenomena. Both positions require logical revisions of classical logic. But anti-realism's logical reforms are better motivated than those of the dialetheist, and the resulting logic is more adequate for the methodological demands of mathematics and empirical science. Priest's prospect of an ‘intuitionist dialetheism’ is unconvincing, both because of important features of intuitionistic logic, such as the independence of the logical operators and the normalizability of proof, and because the intuitionist (or anti-realist) disagrees so strongly on the actual alleged examples of dialetheias in logic and foundations.
There Are No True Contradictions
Authors: Weir Alan
Published: May 2010

This chapter argues that it is both reasonable and worthwhile for the non-dialetheist to engage in dispute with the dialetheist. From principles acceptable to dialetheists, it can be shown that affirming true contradictions involves the violation of meaning constraints; here, appeal is made to the relationship between Quinean matrices of belief and disbelief, and the voluntary practices of accepting and rejection. It is further argued that dialetheism involves an ad hoc asymmetry between the roles of truth and falsity, that it is unable to give an adequate account of the ‘classical recapture’ of the classical mathematics we need for science, and that it cannot provide a non-subjective characterization of the distinction between good and bad contradictions, this implicating it in a form of irrationalism.
The Great Urban Transformation
Authors: Hsing You-tien
Published: May 2010

This book emphasizes the centrality of cities in China's ongoing transformation. Based on fieldwork in twenty-four Chinese cities between 1996 and 2007, the author forwards an analysis of the relations between the city, the state, and society through two novel concepts: urbanization of the local state and civic territoriality. Urbanization of the local state is a process of state power restructuring entailing an accumulation regime based on the commodification of state-owned land, the consolidation of territorial authority through construction projects, and a policy discourse dominated by notions of urban modernity. Civic territoriality encompasses the politics of distribution engendered by urban expansionism, and social actors' territorial strategies toward self-protection. Findings are based on observations in three types of places. In the inner city of major metropolitan centers, municipal governments battle high-ranking state agencies to secure land rents from redevelopment projects, while residents mobilize to assert property and residential rights. At the urban edge, as metropolitan governments seek to extend control over their rural hinterland through massive-scale development projects, villagers strategize to profit from the encroaching property market. At the rural fringe, township leaders become brokers of power and property between the state bureaucracy and villages, while large numbers of peasants are dispossessed, dispersed, and deterritorialized; their mobilizational capacity is consequently undermined.
Chapter 2 Municipal Governments, Socialist Land Masters, and Urban Land Battles
Authors: Hsing You‐tien
Published: May 2010

Chapter 2 discusses local politics at the municipal government level. It focuses on land battles in the urban core between high‐ranking state units (or “socialist land masters”) and municipal governments. It argues that while the socialist land masters occupy premium land parcels inherited from the planned economy, the municipal government's authority is reinforced by a modernist discourse, Western urban planning doctrines, and recent policies that grant authority over state‐owned urban land to the territorial government. Rather than settling the matter of power in the city, however, municipal leaders' granted authority is tested and defined by their political, regulatory, organizational, and moral authority in negotiations with those above, within, and below them. The municipal government's regulatory capacity is especially challenged by a fragmented real estate industry that includes players from state, non‐state, and hybrid sectors.
Chapter 8 A New Territorial Order
Authors: Hsing You‐tien
Published: May 2010

Chapter 8 broadens the scope of this book and makes programmatic connections both between the urbanized local state and China's emerging territorial order, and between civic territoriality and the prospects of grassroots mobilization in Chinese cities and the countryside. Both issues are at the center of the recent property crisis and rural reform in China. On the former, the author proposes that while state power is restructured through the double movement of power decentralization and reconcentration among competing local states, leading cities of metropolitan regions rise to dominate the new territorial order. On the latter, two theoretical connections can be made between civic territoriality and social activism. The first one responds to debates on the relative importance of community and class in urban social movements; the second examines rural collectivism and suggests that while much‐criticized collective land ownership persists in China, peasants' collective organization and identity have been paradoxically dismantled to a significant extent.
Characterization and Epidemiological Significance of Potato Plants Grown from Seed Tubers Affected by Zebra Chip Disease
Authors: Henne D. C. , Workneh F. , Wen A. , Price J. A. , Pasche J. S. , Gudmestad N. C. , Rush C. M.
Published: May 2010

An emerging disease of potato in the United States, known as “Zebra Chip” or “Zebra Complex” (ZC), is increasing in scope and threatens to spread further. Here, we report on studies performed to understand the role of tuberborne ZC in the epidemiology of this disease. Depending on variety, up to 44% of ZC-affected seed tubers (ZCST) were viable, producing hair sprouts and weak plants. Chip discoloration in progeny tubers of ZCST was more severe than those from ZC-asymptomatic seed tubers but varied depending on whether progeny tubers or foliage were positive or negative for ‘Candidatus Liberibacter solanacearum’. A low percentage of greenhouse-grown plants produced by ZCST tested positive for ‘Ca. Liberibacter’. No adult potato psyllids became infective after feeding upon these plants but they did acquire ‘Ca. Liberibacter’ from field-grown plants produced by ZCST. Plants with new ZC infections near plants produced by ZCST were not significantly different from healthy plants, whereas plants affected with ZC from infectious potato psyllids had significantly more ZC infections near either plants produced by ZCST or healthy plants. We conclude that, in areas where ZC is currently established, plants produced by ZCST do not significantly contribute to ZC incidence and spread within potato fields.
Managing Phytophthora Crown and Root Rot in Bell Pepper Using Fungicides and Host Resistance
Authors: Foster J. M. , Hausbeck M. K.
Published: May 2010

A resistant pepper cultivar and nine fungicides were tested in both the field and greenhouse and their ability to limit Phytophthora crown and root rot was demonstrated. In both settings, the resistant pepper ‘Paladin’ and the susceptible pepper ‘Red Knight’ were inoculated with prepared millet seed infested with Phytophthora capsici. Foliar sprays were applied to the pepper plants on a 7-day interval in the field, and foliar sprays or drenches were applied at 7- or 14-day intervals in the greenhouse. Cv. Paladin had significantly less plant death than Red Knight. In the field, plants treated with fluopicolide or mandipropamid had significantly less plant death than the untreated control plants and, in the greenhouse, all fixed effects, including cultivar, fungicide treatment, application method, and application interval, were significant. The interactions among fungicide–cultivar, application method–cultivar, application method–fungicide, and fungicide–cultivar–application method were also significant in the greenhouse. Treatments applied as drenches provided greater control of P. capsici than those applied foliarly. Combining a resistant cultivar with a fungicide applied as a drench may help reduce the incidence of crown and root rot in pepper.
Effects of Chloride and Ammonium Salts on the Incidence of Phytophthora Root and Stem Rot of Soybean
Authors: Canaday C. H. , Schmitthenner A. F.
Published: May 2010

In growth chamber experiments using field soil naturally infested with Phytophthora sojae, addition of KCl at 150 to 400 μg of K per gram of dry soil increased the incidence of Phytophthora root and stem rot on susceptible soybean (Glycine max) compared with a distilled water control. Other potassium salts at 150 to 400 μg of K, phosphorus salts at 20 to 317 μg of P, and sulfate salts of K, Ca, Mg, Na, and Al at 491 μg of SO4 per gram of soil did not affect disease incidence. Application of chloride salts of K, Na, Mg, Ca, NH4, Al, Fe, and Sr at 250 μg of Cl per gram of soil all increased disease incidence compared with the distilled water control. Addition of other ammonium salts also increased disease incidence. Disease incidence increased when KCl at 300 μg of K per gram soil was applied to naturally infested Blount silt loam but not to naturally infested Hoytville silty clay. The effects of chloride salts on plant growth and on natural inoculum of P. sojae were investigated. At 450 μg Cl/g of soil, addition of NaCl increased plant fresh weight but had no effect on germination, emergence, transpiration, height, and dry weight of plants grown in pasteurized, pathogen-free soil. When soybean plants were grown without a deplasmolytic shock and without promoting zoospore release by saturating the soil, the addition of chloride salts at 304 μg of Cl per gram of soil increased disease. In a leaf-disc-baiting bioassay, leaf infection by P. sojae zoospores decreased when 0.01 or 0.02 M KCl was added to soil extracts from flooded soil but was unaffected by KCl at 150 to 600 μg of K per gram of soil applied to the soil 5 days before baiting. Energy-dispersive X-ray analysis of taproots of 5-day-old soybean plants indicated a reduction in the calcium content of the outer cell layers with KCl at 400 μg of K per gram of soil but not with K2SO4. Disease increases with addition of KCl appear to be due to the presence of chloride and may be associated with changes in the micropartitioning of root calcium.
First Report of Leaf Spot of Dracaena reflexa Caused by Burkholderia gladioli Worldwide
Authors: Romberg M. K. , Griffin R. L. , Murugan S. , Quinn B. D. , Alexander B. J. R.
Published: May 2010

In December 2008 (austral summer), a new disease of Dracaena reflexa Lam. cv. Anita was observed in a postentry quarantine greenhouse near Auckland, New Zealand on plants imported from Costa Rica. Symptoms included rust-colored, water-soaked lesions with chlorotic margins approximately 5 by 10 mm. When the disease was first noticed, incidence approached 80%, but subsequent reduction in greenhouse temperature dramatically reduced symptom expression and lesions were only visible on some leaf tips. Bacteria consistently isolated from the lesions on King's medium B (KB) were cream-colored, shiny, and produced a yellow, diffusible, nonfluorescent pigment. All isolates were able to rot onion slices. On the basis of BIOLOG (Hayward, CA) carbon utilization profiles, isolates were initially identified as Burkholderia gladioli (Severini 1913) Yabuuchi et al. 1993 with a probability index of 100% and a similarity index of 0.85. For molecular identification, a near full-length sequence of the 16S rDNA gene was amplified from all isolates using primers fD2 and rP1 (1), obtaining a PCR product of approximately 1,500 bp. The nucleotide sequences were 100% identical to a number of B. gladioli GenBank entries, including Accession Nos. EF193645 and EF088209. To confirm pathogenicity, three isolates (two isolated prior to greenhouse temperature reduction and one after) were used. Three D. reflexa plants were inoculated per bacterial isolate by wounding three young fully expanded leaves on each plant (four wounds per leaf) and spraying the leaves with a bacterial suspension in sterile distilled water at 108 CFU/ml. At the same time, Gladiolus nanus plants were inoculated in a similar manner. Control plants (D. reflexa and G. nanus) were wounded and sprayed with sterile distilled water. All inoculated plants were covered with plastic bags to maintain humidity and placed in a growth chamber at 25°C. At 3 days, all inoculated plants began to show water soaking and reddish coloration around the inoculation sites, and by 7 days, the lesions had expanded to resemble natural infection. Bacteria isolated on KB from the leading edge of each lesion were morphologically identical to the initial isolates. No bacteria were recovered from the wound sites on the control plants. The 16S rDNA sequences of selected isolates from inoculated plants showed 100% identity to the sequences of the initial isolates, thereby fulfilling Koch's postulates. To our knowledge, this is the first report of B. gladioli causing leaf spot of D. reflexa in the world.

Reference: (1) W. G. Weisburg et al. J. Bacteriol. 173:697, 1991.
First Report of Grapevine Virus Sequences Highly Similar to Grapevine Syrah virus-1 from Washington Vineyards
Authors: Mekuria T. A. , Naidu R. A.
Published: May 2010

Grapevine Syrah virus-1 (GSyV-1), a tentative member of the genus Marafivirus in the family Tymoviridae, has recently been found in a declining Syrah grapevine in California vineyards (1). To determine if GSyV-1 is present in grapevines grown in Washington State vineyards, extracts prepared from individual grapevines of six cultivars (Merlot, Chardonnay, Pinot Noir, Lemberger, Cabernet Sauvignon, and Syrah/Shiraz) were tested by single-tube reverse transcription (RT)-PCR using the primer pair GSyV-1 Det-F (5′-CAAGCCATCCGTGCATCTGG-3′) and GSyV-1 Det-R (5′-GCCGATTTGGAACCCGATGG-3′). The primer GSyV-1 Det-F is identical to nucleotides (nt) 1125 to 1144 and GSyV-1 Det-R complementary to nt 1401 to 1420 of the GSyV-1 genome (GenBank Accession No. NC_012484) in the putative movement protein encoding gene (1). DNA fragment of approximately 296 base pairs (bp) was amplified only from 7 of 60 and 2 of 20 individual grapevines of cv. Syrah/Shiraz and Chardonnay, respectively, obtained from geographically separate vineyards. The 296-bp fragments from three Syrah/Shiraz and two Chardonnay grapevines were cloned individually into the pCR2.1 plasmid (Invitrogen Corp., Carlsbad, CA). Three independent clones derived from each DNA fragment were sequenced from both orientations and the sequences edited and assembled using ContigExpress project in the Vector NTI Advance 11 sequence analysis software packages (Invitrogen). Pairwise comparison of four of these sequences (Accession Nos. GU372349–52) showed 99 to 100% amino acid (aa) sequence identity among themselves and with corresponding sequences of GSyV-1. Because of the lack of antibodies, an additional 611-bp fragment specific to the capsid protein (CP) gene of GSyV-1 was amplified from six isolates (five from cv. Syrah/Shiraz, and one from cv. Chardonnay) (Accession Nos. GU372353–66) using primers GSyV-1-F (5′-TGTCGACGCTCCAATGTCTGA-3′) and GSyV-1-R (5′-CATTGCTGCGCTTTGGAGGCTTTA-3′). GSyV-1-F is identical to nt 5775 to 5795 and GSyV-1-R is complementary to nt 6385 to 6408 of the GSyV-1 genome. The amplicons were cloned and sequenced as described above. Comparison of these sequences among themselves and with corresponding sequences of GSyV-1 showed 96 to 99% aa sequence identity, further complementing the results obtained above. To our knowledge, this is the first report of the occurrence of viral sequences closely related to GSyV-1 in Washington vineyards. Together with other reports (1,2), this study suggests that viruses similar to GSyV-1 could be widely distributed in wine grape cultivars across grape-growing regions.

References: (1) M. Rwahnih et al. Virology 387:395, 2009. (2) S. Sabanadzovic. Virology 394:1, 2009.
First Report of Papaya ringspot virus–Type W and Zucchini yellow mosaic virus Infecting Trichosanthes cucumerina in Brazil
Authors: Jadão A. S. , Buriola J. E. , Rezende J. A. M.
Published: May 2010

Trichosanthes cucumerina L., known as snake gourd, is a cucurbitaceous plant that is probably native to and originally domesticated in India. It is cultivated in humid subtropical and tropical countries of Australia, Latin America, and Africa (2). Plants of this species exhibiting symptoms of mosaic and leaf malformation were found during November 2008 near an experimental field of the Departamento de Fitopatologia e Nematologia, Universidade de São Paulo, Piracicaba, State of São Paulo, Brazil. Electron microscopy examination of negatively stained extract of infected tissue showed the presence of filamentous potyvirus-like particles. Sap from these infected plants reacted in plate-trapped antigen (PTA)-ELISA with the antiserum against Papaya ringspot virus–type W (PRSV-W) or Zucchini yellow mosaic virus (ZYMV), but not with the antiserum against Cucumber mosaic virus (CMV) or Zucchini lethal chlorosis virus (ZLCV). PRSV-W and ZYMV were simultaneously transmitted by mechanical inoculation to four plants of Cucurbita pepo cv. Caserta and one plant of T. cucumerina, causing mosaic. In addition, PRSV-W and ZYMV isolates from our virus collection separately infected one plant of T. cucumerina after mechanical inoculation. Infections were confirmed by PTA-ELISA. Total RNA extracted from infected and healthy T. cucumerina was analyzed by reverse transcription (RT)-PCR using a primer pair specific to the coat protein (CP) gene of PRSV-W (4) or ZYMV (3). Fragments of 864 bp and 1,045 bp were amplified with each pair of primers, respectively. Nucleotide sequences directly obtained from purified PCR products were used for further identification of these potyviruses. The nucleotide and deduced amino acid sequences of part of the CP gene (792 nt) of PRSV-W (GenBank Accession No. GU586789) shared 99 and 98% identity, respectively, with that of the Brazilian isolate PRSV-W-C (GenBank Accession No. 4152). The nucleotide and deduced amino acid sequences of the entire CP gene (837 nt) of ZYMV (GenBank Accession No. 6790) shared 91 to 98% and 94 to 100% identity, respectively, with innumerous isolates of ZYMV deposited in the GenBank (e.g., Accession Nos. AB004640, D13914, AB004641, and AJ420019). Natural infection of T. cucumerina by PRSV-W was reported in Nepal (1). To our knowledge, this is the first report of T. cucumerina infected by PRSV-W and ZYMV in Brazil.

References: (1) G. Dahal et al. Ann. Appl. Biol. 130:491, 1997. (2) R. W. Robinson and D. S. Decker-Walters. Cucurbits. CAB International, Wallingford, UK. 1997. (3) K. G. Thomson et al. J. Virol. Methods 55:83, 1995. (4) M. G. S. D. Vechia. Fitopatol. Bras. 28:678, 2003.
First Report of Cucumber mosaic virus in Paeonia lactifera in France
Authors: Cardin L. , Onesto J. P. , Moury B.
Published: May 2010

Chinese peony (Paeonia lactiflora Pall.), a hardy ornamental plant of the family Paeoniaceae cultivated in gardens and for cut flower production, is frequently infected by Tobacco rattle virus (TRV) in the field. The virus usually induces severe mosaic and chlorotic ringspot symptoms in the leaves, decreasing the commercial value of cut flowers. TRV is routinely detected by mechanical inoculation onto Nicotiana tabacum cv Xanthi, where it induces typical necrotic local ringspots in 3 to 7 days, followed by a reverse transcription (RT)-PCR test (2). In 2004, Xanthi test plants inoculated with sap extracts from 4 of 36 P. lactiflora cv. Odile plants grown in a field plot in the region of Hyères (southeast France) showed systemic mosaic symptoms in addition to the TRV-typical response. In each case, Cucumber mosaic virus (CMV) was detected by the reactions of a range of inoculated plants (1), the observation of 30 nm isometric particles in crude leaf extracts with the electron microscope, and by positive reactions in double antibody sandwich (DAS)-ELISAs with specific polyclonal antibodies. In double-immunodiffusion analysis, these isolates were shown to belong to the group II of CMV isolates (3). ELISA of the peony plants confirmed the presence of CMV and revealed two additional infected plants in the spring of 2006. Following isolation from local lesions on Vigna unguiculata and multiplication in Xanthi tobacco plants, one of the isolates was used to inoculate manually or with Myzus persicae aphids 10 CMV-free plants of P. lactiflora cv. Odile obtained from meristem culture. Three months postinoculation, only three of the aphid-inoculated plants were CMV positive by DAS-ELISA. No change was observed at 1 year postinoculation and no symptoms have been observed, even in CMV-infected plants. CMV appears to be latent in P. lactiflora, therefore detection of CMV before vegetative propagation of the plants is advised because of the risks of synergism for symptoms with other viruses such as TRV. To our knowledge this is the first report of CMV in peony.

References: (1) L. Cardin et al. Plant Dis. 87:1263, 2003. (2) D. J. Robinson J. Virol. Methods 40:55, 1992. (3) M. J. Roossinck. J. Virol. 76:3382, 2002.
First Report of Tomato apical stunt viroid in the Symptomless Hosts Lycianthes rantonnetii and Streptosolen jamesonii in the Netherlands
Authors: Verhoeven J. Th. J. , Botermans M. , Jansen C. C. C. , Roenhorst J. W.
Published: May 2010

In 2009, in the framework of surveying for pospiviroids, samples of various ornamental plants from the Netherlands were tested by reverse transcription (RT)-PCR with the primer pairs Pospi1-RE/FW and Vid-RE/FW (2). With primer pair Pospi1-RE/FW, amplicons of the expected size were obtained in two samples of symptomless plants of Lycianthes rantonnetii and Streptosolen jamesonii. Sequencing of the amplicons, which were expected to correspond with partial pospiviroid genomes, showed identities of 100 and 98% to the sequence of Tomato apical stunt viroid (TASVd), NCBI GenBank Accession No. AM777161 (3). For the amplification of the complete viroid genomes, RT-PCRs were performed with primer pair CEVd-FW/RE (1). Sequencing of these amplicons yielded sequences of 364 nt and identities to TASVd AM777161 of 100 and 98.1%, respectively. Therefore, both isolates were identified as TASVd. The sequence variant from S. jamesonii was submitted to the NCBI GenBank as No. GU911351. In addition, both isolates were mechanically inoculated to four tomato plants (Solanum lycopersicum) of cv. Moneymaker. All inoculated plants developed chlorosis and growth reduction after 4 weeks and TASVd infections were confirmed in a bulked sample by RT-PCR with primer pair CEVd-FW/RE after 6 weeks. Hence, two more ornamental host plant species have been identified that may act as symptomless sources of pospiviroid inoculum.

References: (1) N. Önelge. Turk. J. Agric. For. 21:419, 1997. (2) J. Th. J. Verhoeven et al. Eur. J. Plant Pathol. 110:823, 2004. (3) J. Th. J. Verhoeven et al. Plant Dis. 92:973, 2008.
Precise Undersampling Theorems
Authors: Donoho David L. , Tanner Jared
Published: May 2010

Undersampling theorems state that we may gather far fewer samples than the usual sampling theorem while exactly reconstructing the object of interest-provided the object in question obeys a sparsity condition, the samples measure appropriate linear combinations of signal values, and we reconstruct with a particular nonlinear procedure. While there are many ways to crudely demonstrate such undersampling phenomena, we know of only one mathematically rigorous approach which precisely quantifies the true sparsity-undersampling tradeoff curve of standard algorithms and standard compressed sensing matrices. That approach, based on combinatorial geometry, predicts the exact location in sparsity-undersampling domain where standard algorithms exhibitphase transitionsin performance. We review the phase transition approach here and describe the broad range of cases where it applies. We also mention exceptions and state challenge problems for future research. Sample result: one can efficiently reconstruct a k-sparse signal of length N from n measurements, provided n ?? 2k ?? log(N/n), for (k,n,N) large.k ?? N.AMS 2000 subject classifications. Primary: 41A46, 52A22, 52B05, 62E20, 68P30, 94A20; Secondary: 15A52, 60F10, 68P25, 90C25, 94B20.
Flavonoid accumulation in Arabidopsis thaliana root galls caused by the obligate biotrophic pathogen Plasmodiophora brassicae
Authors: PÄSOLD SUSANNE , SIEGEL INA , SEIDEL CLAUDIA , LUDWIG‐MÜLLER JUTTA
Published: May 2010

Three different flavonoids—naringenin, quercetin and kaempferol—accumulate in root galls of Arabidopsis thaliana after infection with the obligate biotrophic pathogen Plasmodiophora brassicae. In addition, high‐performance liquid chromatography and thin layer chromatography analysis indicated that these flavonoids and their glycosides were induced in galls rather than in healthy roots. The transcripts of selected genes involved in the biosynthesis of flavonoids were up‐regulated during the time course of the disease. Some, such as chalcone synthase and chalcone isomerase, were up‐regulated at both times investigated in this study, whereas up‐regulation was observed only at later times for others, such as a flavonol synthase‐like gene. Plants with mutations in different flavonoid biosynthesis genes were slightly more tolerant to clubroot at low infection pressure. However, flavonoid treatment of either leaves or roots did not reduce gall development. The possibility that flavonoids might influence auxin levels by regulating auxin transport or auxin degradation in roots was investigated by measuring auxin levels and response in roots of flavonoid‐deficient mutants and the wild‐type after inoculation with P. brassicae, as well as the antioxidative potential of flavonoids in the peroxidase‐catalysed degradation of indole‐3‐acetic acid. In addition, the auxin transport rate from the shoots to the roots was measured in infected wild‐type or flavonoid mutant plants compared with controls. In conclusion, our results indicate a role of flavonoids in the modulation of auxin efflux in root galls.