The Multigeneic _Rhg1_ Locus: A Model For The Effects on Root Development, Nematode Resistance and Recombination Suppression.

Soybean (Glycine max L. Merr.) resistance to populations (HgType) of _Heterodera glycines I._, the soybean cyst nematode (SCN), requires a functional allele at rhg1. An apoptosis-like response in the giant cells formed around the nematode results 24-48 h after feeding commences. This study aimed to identify the role of the three genes within the rhg1 locus, a receptor like kinase (RLK), a laccase and an ion anti-porter. Used were near isogeneic lines (NILs) that contrasted at their rhg1 alleles. Features of the rhg1 locus, the candidate genes and their nascent transcripts and proteins in roots were elucidated. First, evidence for a syntenic gene cluster was found and the effectiveness of SNP probes for distinguishing the homeolog sequence variant on linkage group (Lg) B1 from alleles at the rhg1 locus on Lg G was shown. Analysis of plant s heterozygous at rhg1 showed that the allele for resistance was dominant. The absence of recombination events among the NILs between the RLK and other 2 genes eliminated the possibility of a monogeneic rhg1 locus. Finally, an effect on root development was discovered. A model for multigeneic resistance based on developmental control of root growth including a mechanism for segregation distortion is presented

The persistence of open access electronic journals

Purpose – Open access (OA) electronic journals have been identified as potentially at risk of loss without more coordinated preservation efforts. The purpose of this paper is to test the current availability of OA electronic journals indexed in the Directory of Open Access Journals (DOAJ). Design/methodology/approach – Using publicly available journal metadata downloaded from DOAJ, individual journal URLs were tested for validity and accessibility using a Microsoft Excel Visual Basic for Applications macro. Findings – Initial results showed 69.51% of the URLs tested returned a successful HTTP status code. The remainder of the URLs returned codes that indicated redirection or errors. Originality/Value – Unlike past studies of link decay, this is not limited to cited references or a specific discipline. This study utilizes the full DOAJ metadata to analyze the persistence of OA electronic journals

Orientation dependence of ferroelectric properties of pulsed-laser-ablated Bi4-xNdxTi3O12 films

Epitaxial (001)-, (118)-, and (104)-oriented Nd-doped Bi4Ti3O12 films have been grown by pulsed-laser deposition from a Bi4-xNdxTi3O12 (x=0.85) target on SrRuO3 coated single-crystal (100)-, (110)-, and (111)-oriented SrTiO3 substrates, respectively. X-ray diffraction illustrated a unique epitaxial relationship between film and substrate for all orientations. We observed a strong dependence of ferroelectric properties on the film orientation, with no ferroelectric activity in an (001)-oriented film; a remanent polarization 2P(r) of 12 muC/cm(2) and coercive field E-c of 120 kV/cm in a (118)-oriented film; and 2P(r)=40 muC/cm(2), E-c=50 kV/cm in a (104)-oriented film. The lack of ferroelectric activity along the c-axis is consistent with the orthorhombic nature of the crystal structure of the bulk material, as determined by powder neutron diffraction. (C) 2003 American Institute of Physics

Complex octahedral tilt phases in the ferroelectric perovskite system LixNa1–xNbO3

We thank STFC for provision of neutron diffraction facilities at ISIS and Dr Aziz Daoud-Aladine for experimental assistance. CALD was supported by an EPSRC DTA studentship (EP/L50579/1).High-temperature phase behavior in the system LixNa1−xNbO3 has been studied by using high-resolution neutron powder diffraction. Each of the three compositions studied in the Na-rich part of the phase diagram (viz., x=0.03,0.08, and 0.12) shows evidence for distinct and complex structural modulations based on different tilting schemes of NbO6 octahedral units. Whilst octahedral tilting is prevalent in the structural chemistry of perovskites the details of the long-range tilt phases are distinct from those previously observed in NaNbO3 itself. A phase with a well-defined fourfold superlattice is observed for the composition Li0.12Na0.88NbO3, and yet more complex phases with modulations based on 20-fold and 30-fold repeats are observed for Li0.03Na0.97NbO3 and Li0.08Na0.92NbO3, respectively. This peculiar structural frustration makes the system LixNa1−xNbO3 a most structurally complex “simple” perovskite.PostprintPostprintPeer reviewe

Review of the Rpt3 Genes Encoding Part of the 26S Proteasome Associated with Loci Underlying Disease Resistance in Soybean

The 26S proteasomal complex is a multifunctional proteolytic machinery of the cell. The proteasome plays role in myriad of cellular functions, which have been further diversified by its separable proteolytic and non-proteolytic sub-complexes. Protein quality control and turnover, cell cycle regulation, gene regulation and DNA repair are among the key processes controlled by the proteasome. Disease resistance in plants invokes changes in all the processes controlled by the 26S proteasome. In this review, the potential contribution of genes encoding the proteasome to disease resistance in soybean (Glycine max L. Merr.) was examined

Using A Minimum Tile Path For Plant Transformations Encompassing the Entire Soybean Genome

Genomes like Glycine max (soybean) that have been highly conserved following increases in ploidy represent a frontier for genome analysis. Many soybean QTL analyzed to date have been composed of gene clusters each with contributing a portion of the trait rather than alleles of single genes. At the Soybean Genome Database (SoyGD) http://soybeangenome.siu.edu the genome browser that integrates and served the publicly available soybean physical map, BAC fingerprint database and genetic map associated genomic data shows a minimum tile of transformation ready BIBAC-like clones in pCLD04541 (pV41; oriV; tra; bom). Sequence resources made available through the DOE genome sequencing project have allowed the minimum tile to be revised and new functional analyses to be made. There are 3,840 MTP clones that appeared to encompass 90% of the genome (see http://soybeangenome.siu.edu/cgi-bin/gbrowse/BES_scaffolds). The BIBAC-like clones (tetR) from E. coli DH10 B were transferred en masse to Agrobacterium tumefaciens by triparental matings with EHA105 (rifR) mediated by pRK2013 (oriP) in DH10B (kanR) in 384 well plates. Although not necessary the extra helper plasmid boosted efficiency 10 fold. Individual A. tumefaciens rifampicin and tetracyclin resistant strains were used for transformation of Arabidopsis thaliana flowers in 384 well arrays. Initially kanamycin selection was used to isolate transgenic plants. Because the BACs were already tetR the recA mutants of A. tumefaciens could not be used (Tn3 insertions). Consequent to this and partial transconjugation events only some inserts are transferred completely while other transformed lines contain a substitution series of deleted inserts anchored on the Ti-left border (LB). These are maintained as kanR mixtures of seed. Phenotypes found for lines transgenic for particular BACs that were repeated include seed composition (protein, oil), development (growth, senescence) and disease resistance (suddean death syndrome (SDS) and soybean cyst nematode (SCN)

Effect of drip irrigation circuits design and lateral line length on: II-flow velocity and velocity head

The objectives of the work were to study the effect of drip irrigation circuits (DIC) and lateral lines lengths (LLL) on: Flow velocity (FV) and velocity head (VH). Laboratory tests were con- ducted at Irrigation Devices and Equipments Tests Laboratory, Agricultural Engineering Research Institute, Agriculture Research Center, Giza, Egypt. The experimental design of laboratory experiments was split in randomized complete block design with three replicates. Laboratory tests carried out on three irrigation lateral lines 40, 60, 80 m (LLL1, LLL2; LLL3) under the following three drip irrigation circuits (DIC): a) one manifold for lateral lines or closed circuits with one manifold of drip irrigation system (CM1DIS); b) closed circuits with two manifolds for lateral lines (CM2DIS), and c) traditional drip irrigation system (TDIS) as a control. Concerning FV values, DIC and LLL treatments could state in the following ascending orders: TDIS \u3c CM1DIS \u3c CM2DIS and LLL1 \u3c LLL2 \u3c LLL3, respectively. FV varied from 0.593 m·sec–1 to 1.376 m·sec–1. i.e. FV \u3c 5 ft·sec–1 and this is necessary to avoid the effect of water hammer in the main and sub-main lines, but in lateral line, it can cause silt and clay precipitation problems. The differences in FV among DIC and LLL were significant at the 1% level. The effect of interaction: DIC X LLL on FV values, were significant at the 1% level. The maximum and minimum values of FV were noticed in these interactions: CM2DIS X LLL3 and TDIS X LLL1, respectively. The following ascending orders TDIS \u3c CM1DIS \u3c CM2DIS and LLL1 \u3c LLL2 \u3c LLL3 expressed their effects on VH respectively. Differences in VH among DIC and/or LLL were significant at the 1% with few exceptions. The effects of interactions: DIC X LLL on VH were significant at the 1% level in some cases. The maximum and minimum values of VH were found in the interactions: CM2DIS X LLL3 and TDIS X LLL1, respectively

Resolving the Submillimeter Background: the 850-micron Galaxy Counts

Recent deep blank field submillimeter surveys have revealed a population of luminous high redshift galaxies that emit most of their energy in the submillimeter. The results suggest that much of the star formation at high redshift may be hidden to optical observations. In this paper we present wide-area 850-micron SCUBA data on the Hawaii Survey Fields SSA13, SSA17, and SSA22. Combining these new data with our previous deep field data, we establish the 850-micron galaxy counts from 2 mJy to 10 mJy with a >3-sigma detection limit. The area coverage is 104 square arcmin to 8 mJy and 7.7 square arcmin to 2.3 mJy. The differential 850-micron counts are well described by the function n(S)=N_0/(a+S^3.2), where S is the flux in mJy, N_0=3.0 x 10^4 per square degree per mJy, and a=0.4-1.0 is chosen to match the 850-micron extragalactic background light. Between 20 to 30 per cent of the 850-micron background resides in sources brighter than 2 mJy. Using an empirical fit to our >2 mJy data constrained by the EBL at lower fluxes, we argue that the bulk of the 850-micron extragalactic background light resides in sources with fluxes near 1 mJy. The submillimeter sources are plausible progenitors of the present-day spheroidal population.Comment: 5 pages, accepted by The Astrophysical Journal Letter

Effects of drip irrigation circuit design and lateral line lengths: I—On pressure and friction loss

Laboratory tests were conducted at the Irrigation Devices and Equipment’s Test Laboratory, Agricultural Engineering Research Institute, Agriculture Research Center, Giza, Egypt. The experimental design of laboratory experiments was split in randomized complete block design with three replicates. Laboratory tests carried out on three irrigation lateral lines of 40, 60, 80 m under the following three drip irrigation circuit (DIC) designs; 1) one manifold for lateral lines or closed circuits with one manifold of drip irrigation system (CM1DIS); 2) closed circuits with two manifolds for lateral lines (CM2DIS), and 3) traditional drip irrigation system (TDIS) as a control. The aims of the work were to study the effect of drip irrigation circuits (DIC) and lateral lines lengths (LLL; where): (LLL1 = 40 m, LLL2 = 60 m, and LLL3 = 80 m) on pressure head (PH) and friction loss (FL). Regarding to LLL and according to PH values, DIC designs could be ranked in the following ascending order: TDIS \u3c CM1DIS \u3c CM2DIS. The differences in PH among DIC de-signs were significant at the 1% level. The de-pressive effects of LLL on PH could be ranked in the following ascending order: LLL1 \u3c LLL2 ≤ LLL3. Differences in PH among LLL treatments were significant at the 1% level except that be-tween LLL2 and LLL3. The effects of interactions among: DIC × LLL on PH were significant at the 1% level with some exceptions. The highest value of PH (9.5 m) and the lowest one (6.05 m) were achieved in the interactions of CM2DIS × LLL1 and TDIS × LLL3, respectively. The shapes of the energy gradient lines were affected by DIC and LLL treatments used through their effect on ΔH/H ratio. However, they followed similar trends. According to the FL values, DIC and LLL treatments could be ranked in the following descending orders TDIS \u3e CM1DIS \u3e CM2DIS and LLL1 \u3e LLL2 \u3e LLL3. The differences in FL among DIC and LLL were significant and the effects of interactions among DIC × LLL on FL were significant at the 1% level. The maximum and mi- nimum values of FL were obtained in the inter-actions: TDIS × LLL3 and CM2DIS × LLL1, respectively. Therefore, the CM2DIS system is recommended for use where technically feasible

Simultaneous extraction, optimization, and analysis of flavonoids and polyphenols from peach and pumpkin extracts using a TLC-densitometric method

Background: The use of medicinal plants has been reported throughout human history. In the fight against illnesses, medicinal plants represent the primary health care system for 60 % of the world’s population. Flavonoids are polyphenolic compounds with active anti-microbial properties; they are produced in plants as pigments. Quercetin, myricetin, and rutin are among the most well-known and prevalent flavonoids in plants, with an antioxidant activity capable of decreasing the oxidation of low density lipoproteins [LDLs]. To date, this research is the first of its kind to employ a coupled thin-layer chromatography (TLC) and a densitometric quantification method with a Box-Behnken design (BBD) response surface methodology (RSM) for optimization of ultrasonic-assisted extraction and determination of rutin and quercetin from peach and ellagic acid and myricetin from pumpkin fruits. Results: The effect of process variables (extraction temperature (°C), extraction power (%) and extraction time (min)) on ultrasound-assisted extraction (UAE) were examined by using BBD and RSM. TLC followed by Quantity-One™ (BioRad) image analysis as a simple and rapid method was used for identification and quantification of the compounds in complex mixtures. The results were consistent under optimal conditions among the experimental values and their predicted values. A mass spectrometry (MALDI-TOF MS) technique was also used to confirm the identity of the natural products in the TLC spots resolved. Conclusion: The results show that the coupled TLC-densitometric methods & BBD can be a very powerful approach to qualitative and quantitative analysis of; rutin and quercetin from peach extracts; and ellagic acid and myricetin contents from pumpkin extracts