Identification of I-7 expands the repertoire of genes for resistance to Fusarium wilt in tomato to three resistance gene classes

The tomato I-3 and I-7 genes confer resistance to Fusarium oxysporum f. sp. lycopersici (Fol) race 3 and were introgressed into the cultivated tomato, Solanum lycopersicum, from the wild relative Solanum pennellii. I-3 has been identified previously on chromosome 7 and encodes an S-receptor-like kinase, but little is known about I-7. Molecular markers have been developed for the marker-assisted breeding of I-3, but none are available for I-7. We used an RNA-seq and single nucleotide polymorphism (SNP) analysis approach to map I-7 to a small introgression of S. pennellii DNA (c. 210 kb) on chromosome 8, and identified I-7 as a gene encoding a leucine-rich repeat receptor-like protein (LRR-RLP), thereby expanding the repertoire of resistance protein classes conferring resistance to Fol. Using an eds1 mutant of tomato, we showed that I-7, like many other LRR-RLPs conferring pathogen resistance in tomato, is EDS1 (Enhanced Disease Susceptibility 1) dependent. Using transgenic tomato plants carrying only the I-7 gene for Fol resistance, we found that I-7 also confers resistance to Fol races 1 and 2. Given that Fol race 1 carries Avr1, resistance to Fol race 1 indicates that I-7-mediated resistance, unlike I-2- or I-3-mediated resistance, is not suppressed by Avr1. This suggests that Avr1 is not a general suppressor of Fol resistance in tomato, leading us to hypothesize that Avr1 may be acting against an EDS1-independent pathway for resistance activation. The identification of I-7 has allowed us to develop molecular markers for marker-assisted breeding of both genes currently known to confer Fol race 3 resistance (I-3 and I-7). Given that I-7-mediated resistance is not suppressed by Avr1, I-7 may be a useful addition to I-3 in the tomato breeder's toolbox.

Self and peer review in dance classes using personal video feedback

Many forms of formative feedback are used in dance training to refine the dancer’s spatial and kinaesthetic awareness in order that the dancer’s sensorimotor intentions and observable danced outcomes might converge. This paper documents the use of smartphones to record and playback movement sequences in ballet and contemporary technique classes. Peers in pairs took turns filming one another and then analysing the playback. This provided immediate visual feedback of the movement sequence as performed by each dancer. This immediacy facilitated the dancer’s capacity to associate what they felt as they were dancing with what they looked like during the dance. The often-dissonant realities of self-perception and perception by others were thus guided towards harmony, generating improved performance and knowledge relating to dance technique. An approach is offered for potential development of peer review activities to support summative progressive assessment in dance technique training.

On the coalescence of twisted flux tubes

We study the problem of the coalescence of twisted flux tubes by assuming that the azimuthal field lines reconnect at a current sheet during the coalescence process and everywhere else the magnetic field is frozen in the fluid. We derive relations connecting the topology of the coalesced flux tube with the topologies of the initial flux tubes, and then obtain a structure equation for calculating the field configuration of the coalesced flux tube from the given topology. Some solutions for the two extreme cases of low-β plasma and high-β plasma are discussed. The coalesced flux tube has less twist than the initial flux tube. Magnetic helicity is found to be exactly conserved during the coalescence, but the assumptions in the model put a constraint on the energy dissipation so that we do not get a relaxation to the minimum-energy Taylor state in the low-β case. It is pointed out that the structure equation connecting the topology and the equilibrium configuration is quite general and can be of use in many two-dimensional flux tube problems.

The importance of context in engaging students large first year management classes: A case study

Engaging large first year classes in tertiary education poses a number of significant challenges, most of which have been discussed by others. One area that has not received the kind of attention that it warrants is the context within which the engagement activities take place. This paper examines both the processes used to engage a large first year management class in a major city university and how the context of the classes shaped activities and student responses to these activities. It was recognised that students had certain types of learning styles, but given the total number of students (in excess of 1200) it was realised that is would be impossible to cater to all possibilities. A key outcome of the exercise was the importance of context in shaping student behaviours.

N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yI)colcemid, a probe for different classes of colchincine-binding site on tubulin

The nature of binding of 7-nitrobenz-2-oxa-1,3-diazol-4-yl-colcemid (NBD-colcemid), an environment-sensitive fluorescent analogue of colchicine, to tubulin was tested. This article reports the first fluorometric study where two types of binding site of colchincine analogue on tubulin were detected. Binding of NBD-colcemid to one of these sites equilibrates slsowly. NBD-colcemid competes with colchicine for this site. Binding of NBD-colcemid to this site also causes inhibition of tubulin self-assembly. In contrast, NBD-colcemid binding to the other site is characterised by rapid equilibration and lack of competition with colchicine. Nevertheless, binding to this site is highly specific for the cholchicine nucleus, as alkyl-NBD analogues have no significant binding activity. Fast-reaction-kinetic studies gave 1.76 × 105 M–1 s–1 for the association and 0.79 s–1 for the dissociation rate constants for the binding of NBD-colcemid to the fast site of tubulin. The association rate constants for the two phases of the slow site are 0.016 × 10–4 M–1 s–1 and 3.5 × 10–4 M–1 respectively. These two sites may be related to the two sites of colchicine reported earlier, with binding characteristics altered by the increased hydrophobic nature of NBD-colcemid.

Equivalence conditions for classes of linear and non-linear distributed parameter systems

Equivalence of certain classes of second-order non-linear distributed parameter systems and corresponding linear third-order systems is established through a differential transformation technique. As linear systems are amenable to analysis through existing techniques, this study is expected to offer a method of tackling certain classes of non-linear problems which may otherwise prove to be formidable in nature.

Maximum compatible classes from compatibility matrices

A fast algorithm for the computation of maximum compatible classes (mcc) among the internal states of an incompletely specified sequential machine is presented in this paper. All the maximum compatible classes are determined by processing compatibility matrices of progressingly diminishing order, whose total number does not exceed (p + m), where p is the largest cardinality among these classes, and m is the number of such classes. Consequently the algorithm is specially suitable for the state minimization of very large sequential machines as encountered in vlsi circuits and systems.

Thermal correlation functions of twisted quantum fields

We derive the thermal correlators for twisted quantum fields on noncommutative spacetime. We show that the thermal expectation value of the number operator is same as in commutative spacetime, but that higher correlators are sensitive to the noncommutativity parameters phi(mu nu).

Conformational analysis of the right-hand twisted antiparallel β-Structure

The conformational analysis of a pair of two-linked peptide units in the anti-parallel arrangement is reported here with a view to study the effect of association of one chain with the other. The pair of two-linked peptide units were fixed in space through the hydrogen bonds between them, in accordance with certain hydrogen bond criteria. Model building was undertaken to ascertain whether the proximity of the side-chains could be used to eliminate any one of the right-hand twisted, left-hand twisted or regular β-structures. Stereochemically, it was found possible with all of them. The preference for a right-hand twisted β-structure, however, was indicated by the classical energy calculations. The relevance of the results thus obtained is discussed in the context of the preferential right-hand twist of the β-pleated sheets present in globular proteins. The agreement between the minimum energy conformations obtained for the pair of two-linked peptide units and the globular protein data is also indicated.

Why Don't Students Talk? Causes of Foreign Language Communication Apprehension in English Classes: A Comparison of High Apprehensive and Low Apprehensive Upper Secondary Students.

OBJECTIVES. Oral foreign language skills are an integral part of one's social, academic and professional competence. This can be problematic for those suffering from foreign language communication apprehension (CA), or a fear of speaking a foreign language. CA manifests itself, for example, through feelings of anxiety and tension, physical arousal and avoidance of foreign language communication situations. According to scholars, foreign language CA may impede the language learning process significantly and have detrimental effects on one's language learning, academic achievement and career prospects. Drawing on upper secondary students' subjective experiences of communication situations in English as a foreign language, this study seeks, first, to describe, analyze and interpret why upper secondary students experience English language communication apprehension in English as a foreign language (EFL) classes. Second, this study seeks to analyse what the most anxiety-arousing oral production tasks in EFL classes are, and which features of different oral production tasks arouse English language communication apprehension and why. The ultimate objectives of the present study are to raise teachers' awareness of foreign language CA and its features, manifestations and impacts in foreign language classes as well as to suggest possible ways to minimize the anxiety-arousing features in foreign language classes. METHODS. The data was collected in two phases by means of six-part Likert-type questionnaires and theme interviews, and analysed using both quantitative and qualitative methods. The questionnaire data was collected in spring 2008. The respondents were 122 first-year upper secondary students, 68 % of whom were girls and 31 % of whom were boys. The data was analysed by statistical methods using SPSS software. The theme interviews were conducted in spring 2009. The interviewees were 11 second-year upper secondary students aged 17 to 19, who were chosen by purposeful selection on the basis of their English language CA level measured in the questionnaires. Six interviewees were classified as high apprehensives and five as low apprehensives according to their score in the foreign language CA scale in the questionnaires. The interview data was coded and thematized using the technique of content analysis. The analysis and interpretation of the data drew on a comparison of the self-reports of the highly apprehensive and low apprehensive upper secondary students. RESULTS. The causes of English language CA in EFL classes as reported by the students were both internal and external in nature. The most notable causes were a low self-assessed English proficiency, a concern over errors, a concern over evaluation, and a concern over the impression made on others. Other causes related to a high English language CA were a lack of authentic oral practise in EFL classes, discouraging teachers and negative experiences of learning English, unrealistic internal demands for oral English performance, high external demands and expectations for oral English performance, the conversation partner's higher English proficiency, and the audience's large size and unfamiliarity. The most anxiety-arousing oral production tasks in EFL classes were presentations or speeches with or without notes in front of the class, acting in front of the class, pair debates with the class as audience, expressing thoughts and ideas to the class, presentations or speeches without notes while seated, group debates with the class as audience, and answering to the teacher's questions involuntarily. The main features affecting the anxiety-arousing potential of an oral production task were a high degree of attention, a large audience, a high degree of evaluation, little time for preparation, little linguistic support, and a long duration.

A Multi frequency study of Radio Intensity Variations For Active Galactic Nuclei of Different Optical Classes

A study of radio intensity variations at seven frequencies in the range 0.3 to 90 GHz for compact extragalactic radio sources classified as BL Lacs and high- and low-optical polarization quasars (HPQs and LPQs) is presented. This include the results of flux-density monitoring of 33 compact sources for three years at 327 MHz with the Ooty Synthesis Radio Telescope. The degrees of 'short-term' (tau less than about 1 yr) variability for the three optical types are found to be indistinguishable at low frequencies (less than 1 GHz), pointing to an extrinsic origin for the low-frequency variability. At high frequencies, a distinct dependence on optical type is present, the variability increasing from LPQs, through HPQs to BL Lacs. This trend persists even when only sources with ultra-flat radio spectra (alpha greater than -0.2) are considered. Implications of this for the phenomenon of high-frequency variability and the proposed unification schemes for different optical types of active galactic nuclei are discussed.

3,12-dinitro-5,10,15,20-tetraphenylporphyrin- an example of a twisted intramolecular charge-transfer system

he porphyrin ring in the title compound, 10,19-dinitro-2,7,12,17-tetraphenyl-21,22,23,24-tetraazapenta-cyclo[16.2.1.1(3,6).1(8,11).1(13,16)]tetracosa-1,3,5,7,9,11(23),-12,14,16,18(21),19-undecaene 0.5-dichloromethane solvate, C44H28N6O4.0.5CH2Cl2, adopts a saddle conformation with neighbouring pyrrole rings tilted with respect to each other. The two nitro groups are situated on alternate pyrrole rings and have their planes angled away from those of the pyrrole rings, thereby indicating that interaction between the porphyrin and nitro groups is slight.

Hierarchies of circuit classes that are closed under complement

We examine three hierarchies of circuit classes and show they are closed under complementation. (1) The class of languages recognized by a family of polynomial size skew circuits with width O(w), are closed under complement. (2) The class of languages recognized by family of polynomial size circuits with width O(w) and polynomial tree-size, are closed under complement. (3) The class of languages recognized by a family of polynomial size, O(log(n)) depth, bounded AND fan-in with OR fan-in f (f⩾log(n)) circuits are closed under complement. These improve upon the results of (i) Immerman (1988) and Szelepcsenyi (1988), who show that 𝒩L𝒪𝒢 is closed under complementation, and (ii) Borodin et al. (1989), who show that L𝒪𝒢𝒞ℱL is closed under complement

Twisted aromatics, 9-anthryl and 1-pyrenyl terpyridines organize into novel multi-directional 'ladder-like' motifs in the solid state

9-Anthryl and 1-pyrenyl terpyridines (1 and 2, respectively), key precursors for the design of novel fluorescent sensors have been synthesized and characterized by H-1 NMR, mass spectroscopy and X-ray crystallography. Twisted molecular conformations for each 1 and 2 were observed in their single crystal structures. Energy minimization calculations for the 1 and 2 using the semi-empirical AM1 method show that the 'twisted' conformation is intrinsic to these systems. We observe interconnected networks of edge-to-face CH...pi interactions, which appear to be cooperative in nature, in each of the crystal structures. The two twisted molecules, although having differently shaped polyaromatic hydrocarbon substituents, show similar patterns of edge-to-face CH...pi interactions.The presently described systems comprise of two aromatic surfaces that are almost orthogonal to each other. This twisted or orthogonal nature of the molecules leads to the formation of interesting multi-directional ladder like supramolecular organizations. A combination of edge-to-face and face-to-face packing modes helps to stabilize these motifs. The ladder like architecture in 1 is helical in nature. (C) 2002 Published by Elsevier Science B.V.