Leavitt path algebras satisfying a polynomial identity

Leavitt path algebras L of an arbitrary graph E over a field K satisfying a polynomial identity are completely characterized both in graph-theoretic and algebraic terms. When E is a finite graph, L satisfying a polynomial identity is shown to be equivalent to the Gelfand-Kirillov dimension of L being at most one, though this is no longer true for infinite graphs. It is shown that, for an arbitrary graph E, the Leavitt path algebra L has Gelfand-Kirillov dimension zero if and only if E has no cycles. Likewise, L has Gelfand-Kirillov dimension one if and only if E contains at least one cycle, but no cycle in E has an exit.Comment: 12 page

Hirayama disease: a rare neurological condition of cervical cord pathology

The disease is characterized by a progressive muscle weakness and wasting of distal upper limb muscles sparing brachioradialis. The pathology is in the lower cervical cord due to forward displacement of dural sac and spinal cord by neck flexion. Repeated neck flexion may result in ischemia of the lower cervical anterior horns. The diagnosis can be confirmed by MRI, EMG. It requires a high degree of suspicion in a young patient presenting with unilateral upper limb distal muscle weakness with no sensory involvement, as early diagnosis will help in preventing the progression of the disease by employing simple measures like usage of a cervical collar. We report a case of a 25 year old man presenting with progressive distal upper limb muscle wasting, on investigating further diagnosed to have Hirayama disease

Molecular detection and characterization of phytoplasma associated with China aster (Callistephus chinensis) phyllody in India

China aster (Callistephus chinensis L.) is one of the most popular annual flowering plant grown through-out the world. Phyllody disease of China aster is a phytoplasma associated disease that induces severe economic losses. Phytoplasmal disease in China aster was assessed for phytoplasma by direct polymerase chain reaction primed by using phytoplasma universal primer pairs PI/P7. A 1.8 Kb DNA fragments encoding the portion of phyto-plasma 16SrDNA amplified by PCR was cloned and sequenced. Sequencing of the PCR product and BLAST analy-sis indicated that China aster phyllody phytoplasma strain shared maximum sequence identity (99%) with strains of Peanut Witches’ broom (16SrII) phytoplasma group. Phylogenetic relationship of 16SrDNA sequence of China aster phyllody phytoplasma strain in the present study confirmed association of Peanut Witches’ broom (16SrII) group of phytoplasmas with China aster phyllody disease in India

Validation of SSR Markers Linked to the Bean Common Mosaic Virus (BCMV) Resistance in Cowpea (\u3cem\u3eVigna unguiculata\u3c/em\u3e L.) Genotypes

Cowpea, Vigna unguiculata (L.) is one of the important grain and fodder legume crops in the world, especially in tropics and subtropics. Which can adapted different climatic conditions such as high temperature and drought. It is not only important as a grain and fodder but also improve fertility of poor soils by fixing atmospheric nitrogen. An estimated cultivated area of cowpea is 12.5mha in worldwide (FAOSTAT, 2013). The grain and fodder productivity of cowpea are greatly affected by a number of biotic factors such as plant pathogens and insect pests. Among plant pathogens, viruses are considered to be a major constraint (Gioi et al., 2010). More than 40 viruses are reported from cowpea growing areas of the world. Among viruses, Bean common mosaic virus (BCMV) is very serious problem on cowpea in southern part of India especially cowpea growing areas of Karnataka. The BCMV is a member of potyvirus group and it can infect other legume crop family. Virus is seed borne and easily spread by aphids. Its chemical and cultural control neither economical nor ecofriendly. The host plant resistance has been proved the best strategy for its management. Hence it is necessary to identify stable resistance sources for BCMV disease in cowpea. Therefore large scale screening is needed to identify the durable resistance among diverse genotypes of cowpea. The basic requirements for any crop improvement programme are genetic variation for the trait of interest

Biological relationship of Bean common mosaic virus (BCMV) infecting cowpea with leguminous plant species

Bean common mosaic virus (BCMV) associated with cowpea mechanically inoculated to different legumi-nous plants. Out of nineteen including cowpea Var.C-152, the virus was easily transferred to ten different legumi-nous hosts. All other hosts assessed for the presence of BCMV were found to be uninfected. The number of days taken for symptom expression and symptoms were varied within plant species. Pole bean expressed mosaic symp-tom after long incubation period (15-18 days) whereas, shorter incubation period was observed in common bean and rice bean (7- 10 days). BCMV produced chlorosis, mosaic, leaf distortion, puckering, vein banding, vein clearing and vein netting on cowpea(C-152). A typical virus symptom, mosaic was observed in green gram, common bean, lime bean, rice bean and yard long bean, whereas, leaf rolling and leaf distortion was observed in black gram, pole bean and snap bean. The virus-host relationship was confirmed by back inoculation test to C. amaranticolor. Further symptomatic plants were subjected for Reverse Transcriptase polymerase chain reaction (RT-PCR) for molecular confirmation using BCMV coat protein (CP) specific primer pair. A PCR fragment size of 439bp was amplified for the symptomatic plants. The results generated indicated the ability of a plant to support virus expression and host speci-ficity of BMCV within the leguminous plant species

Several methods applied to measuring residual stress in a known specimen

In this study, a beam with a precisely known residual stress distribution provided a unique experimental opportunity. A plastically bent beam was carefully prepared in order to provide a specimen with a known residual stress profile. 21Cr-6Ni-9Mn austenitic stainless steel was obtained as 43 mm square forged stock. Several methods were used to determine the residual stresses, and the results were compared to the known values. Some subtleties of applying the various methods were exposed

Ratio of pions to protons and ratio of neutral to charged interacting particles at mountain altitude of 800 gm/cm<SUP>2</SUP>

Using a combined set-up of a multiplate cloud chamber, an air Cerenkov counter and a total absorption spectrometer, the ratio of pions to protons not associated with large air showers has been determined to be 0&#183;50 &#177; &#183;07 in the energy region 20-40 GeV at an altitude of 800 gm/cm2. In the same energy region the ratio of neutral to charged particles is found to be 0.66 &#177; &#183;07. From the ratio of neutrons to protons deduced from these measurements (i.e., 0&#183;99 &#177; &#183;11), it is concluded that most of the charge excess of nuclear active particles of energies &gt; 20 GeV at mountain altitudes and sea-level is due to pions

Evaluation of pigeonpea genotypes for resistance to pigeonpea sterility Mmsaic Vvrus - B Isolate

Pigeonpea genotypes (89) were evaluated for resistance to Pigeonpea sterility mosaic virus Bangalore isolate (PPSMV-B). Of these, three genotypes, ICP 7035, MAL 14 and MAL 19, were found resistant, and two genotypes, ICP 6997 and ICP 8862, were tolerant to PPSMV-B. All the resistant lines tested negative to virus in enzyme-linked immunosorbent assay (ELISA) using PPSMV polyclonal antiserum. The resistant lines can be used in breeding programme for developing PPSMV-resistant high yielding cultivar

Evaluation of Advanced Peanut Breeding Lines for Resistance to Late Leaf Spot and Rust

Peanut (Arachis hypogaea L.) in India are grown in 6.7 million ha with a total production of 6.5 million t and an average productivity of <1 t/ha. The rainy season (June/July- Oct/Nov) is the main cropping season for peanut where the crop is grown generally under rainfed conditions. Rainy season productivity (0.8 t/ha) is much lower than that of the postrainy season. Late leaf spot (LLS) caused by Phaeoisariopsis personata..............