Characterisation of an inbred mouse strain with a deletion of the [alpha]-synuclein locus.

mRNA expression profiling was performed on a knock-in mouse model with a mutation in the NMDA receptor subunit NRl (N598R) that affects the receptors' function as coincidence detector. This approach was aimed at identifying downstream effects produced by the Ca2+ influx through NMDA receptors at the level of gene expression. cDNA array technology revealed striking differences only in the mRNA expression level of [alpha]-synuclein, a protein that has been implicated in the pathophysiology of a range of neurodegenerative diseases. However, this was not caused by the NRl mutation, but by a chromosomal deletion of the [alpha]-synuclein gene locus in the C57BL/6J inbred mice that were used for backcrossing the mutant strain. The deletion was shown to be present only in a subpopulation of C57BL/6J mice, now- referred to as C57BL/6JOlaHsd-Del(6)Snca1Slab. In addition to [alpha]-synuclein, other genes may be affected by the deletion that is estimated to be 120-500 kb in size. [alpha]-synuclein-deficient animals appear phenotypically normal. They show no compensatory upregulation of other members of the synuclein family, namely [alpha]-synuclein and [alpha]-synuclein. Similarly, the expression of synphilin-1, a known interacting partner of [alpha]-synuclein was unaffected. The C57BL/6JOlaHsd-Del(6)SncalSlab mouse model should help in the understanding of the physiological function of [alpha]-synuclein and its involvement in synucleinopathies. Also, the findings exemplify unexpected complications that may arise during the study of transgenic models or inbred strains. A Sindbis virus system was developed for the expression of fluorescent [alpha]-synuclein fusion proteins in neurons. A range of recombinant virion preparations was tested in plaque assays and the expression of the recombinant proteins was characterised. Initial analysis of the expression of [alpha]-synuclein-eGFP in organotypic hippocampal neurons suggested that the protein accumulated in presynaptic locations. This approach could be used for the study of the subcellular localisation and of protein interactions of [alpha]-synuclein

Polarization-controlled single photons

Vacuum-stimulated Raman transitions are driven between two magnetic substates of a rubidium-87 atom strongly coupled to an optical cavity. A magnetic field lifts the degeneracy of these states, and the atom is alternately exposed to laser pulses of two different frequencies. This produces a stream of single photons with alternating circular polarization in a predetermined spatio-temporal mode. MHz repetition rates are possible as no recycling of the atom between photon generations is required. Photon indistinguishability is tested by time-resolved two-photon interference.Comment: 4 pages, 3 figure

Deletion of the alpha-synuclein locus in a subpopulation of C57BL/6J inbred mice

BACKGROUND: The presynaptic protein α-synuclein is involved in a range of neurodegenerative diseases. Here we analyze potential compensatory mechanisms in α-synuclein null mutant mice. Furthermore, the findings reveal problems that may be associated with inbred mouse strains. RESULTS: Expression profiling by cDNA array technology in a transgenic mouse model revealed striking differences only in the expression level of α-synuclein. This was caused by a chromosomal deletion of the α-synuclein locus in the C57BL/6J inbred strain used for backcrossing. However, the deletion is only present in a subpopulation of C57BL/6J mice, namely animals from Harlan. No other genes are known to be affected by the deletion, which is estimated to be smaller than 2 cM. We propose to name this strain C57BL/6S. C57BL/6S animals appear phenotypically normal. They show no upregulation of β-synuclein or γ-synuclein, excluding a compensatory mechanism. Also, the expression of synphilin-1 was unaffected. CONCLUSIONS: The C57BL/6S strain should help in the understanding of the physiological function of α-synuclein and its involvement in synucleinopathies. Also, the findings exemplify unexpected complications that may arise during the study of transgenic models or inbred strains, in particular when combined with genome wide screening techniques

Impact of soil management practices on soil fertility and disease suppressiveness

Soil management practices are targeted to provide adequate crop nutrition and to ensure durable soil fertility and to avoid negative environmental impacts. Soil management also aims to reduce pest and disease pressure on crops. Organic farming is believed to increase soil suppressiveness towards soil-borne diseases as well aerial diseases. In this paper we will discuss the potential of soil manage-ment as a tool to improve disease suppressiveness in practice

Developing Belief in Online Teaching: Efficacy and Digital Transformation

Digital pedagogies, blended, hybrid, and online learning are not new, indeed discussions about their role in higher education are well documented. With some notable exceptions however, many of these discussions, and many more attempts at implementation, have been small in scale, operating at the level of a single course, or even single members of staff. Barriers at national, institutional and personal levels all contributed to slow uptake of digital learning. The summer of 2020 though saw institutions across the UK, and indeed the world, forced into rapid transition to online learning in the face of the COVID-19 pandemic. This paper examines our work supporting a school - which achieved high student satisfaction rates - within a large post-92 university in this transition. With specific attention to academic identity and efficacy, we examine the approaches that were taken in helping academics to climb over the digital hurdle towards good online teaching. We suggest that a three-pronged approach is needed to overcome these barriers and create the belief in digital that is needed for a successful online transition, and for continued growth. These are a collective ‘all in it together’ approach, placing curriculum, rather than technology at the heart of the work, and also ensuring solid institutional support that does not rely on early adopters

Mapping the energy and diffusion landscapes of membrane proteins at the cell surface using high-density single-molecule imaging and Bayesian inference: application to the multi-scale dynamics of glycine receptors in the neuronal membrane

Protein mobility is conventionally analyzed in terms of an effective diffusion. Yet, this description often fails to properly distinguish and evaluate the physical parameters (such as the membrane friction) and the biochemical interactions governing the motion. Here, we present a method combining high-density single-molecule imaging and statistical inference to separately map the diffusion and energy landscapes of membrane proteins across the cell surface at ~100 nm resolution (with acquisition of a few minutes). When applying these analytical tools to glycine neurotransmitter receptors (GlyRs) at inhibitory synapses, we find that gephyrin scaffolds act as shallow energy traps (~3 kBT) for GlyRs, with a depth modulated by the biochemical properties of the receptor-gephyrin interaction loop. In turn, the inferred maps can be used to simulate the dynamics of proteins in the membrane, from the level of individual receptors to that of the population, and thereby, to model the stochastic fluctuations of physiological parameters (such as the number of receptors at synapses). Overall, our approach provides a powerful and comprehensive framework with which to analyze biochemical interactions in living cells and to decipher the multi-scale dynamics of biomolecules in complex cellular environments.Comment: 23 pages, 4 figure

Immature stages of Spodoptera eridania (Lepidoptera: noctuidae): developmental parameters and host plants.

This study aimed to detail the temporal and morphological parameters of the immature stages of southern armyworm Spodoptera eridania (Stoll, 1782) with larvae feed on artificial diet, under controlled conditions (25?±?1°C, 70?±?10% relative humidity and 14-h photophase) and gather information about their larval host plants. The viability of the egg, larval, pupal, and prepupal stages was 97.82, 93.62, 96.42, and 97.03%, respectively. The average duration of the egg, larval, pupal, and pre-pupal stages was 4.00, 16.18, 1.58, and 9.17 d, respectively. During the larval stage, 43.44% of females passed through seven instars, observing that the female's development was significant slower than males. The female larvae that developed through six and seven instars exhibited a mean growth rate of 1.52 and 1.44, respectively. Female pupae were significantly larger, exhibiting faster development than males. The rearing method proved to be adequate, providing more detailed observations of the biological cycle, especially at the larval stage, and resulting in an overall survival of almost 85%. Two hundred two plant species belonging to 58 families are listed as natural hosts for S. eridania, mainly including Asteraceae, Fabaceae, Solanaceae, Poaceae, Amaranthaceae, and Malvaceae

Cell wall chitosan is necessary for virulence in the opportunistic pathogen Cryptococcus neoformans

Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningoencephalitis. Its cell wall is composed of glucans, proteins, chitin, and chitosan. Multiple genetic approaches have defined a chitosan-deficient syndrome that includes slow growth and decreased cell integrity. Here we demonstrate chitosan is necessary for virulence and persistence in the mammalian host

Photocycloaddition Of 4,5\u27,8-trimethylpsoralen And Oleic-acid Methyl-ester - Product Structures And Reaction-mechanism

The stereochemical structures of the four adducts formed between oleic acid methyl ester (OAME) and 4,5\u27,8-trimethylpsoralen (tmPso) have been determined. Assignment of the tmPso \u27H NMR spectrum was accomplished by analogy to two coumarin model compounds and with the use of homonuclear decoupling and resonance enhancement. Assignment of the lH NMR spectra for the OAME-tmPso adducts was made by analogy to the spectra of OAME and tmPso and using 2D &resolved and COSY analyses. The configurations of the cyclobutyl rings in these adducts was determined by The stereochemical structures of the four adducts formed between oleic acid methyl ester (OAME) and 4,5\u27,8-trimethylpsoralen (tmPso) have been determined. Assignment of the tmPso \u27H NMR spectrum was accomplished by analogy to two coumarin model compounds and with the use of homonuclear decoupling and resonance enhancement. Assignment of the lH NMR spectra for the OAME-tmPso adducts was made by analogy to the spectra of OAME and tmPso and using 2D &resolved; and COSY analyses. The configurations of the cyclobutyl rings in these adducts was determined by MM2 energy minimization calculations, homonuclear \u27H NOE analysis, and comparison of products obtained with cis-OAME and trans-EAME (elaidic acid methyl ester). Only four of the eight possible disastereomeric adducts are detected. These adducts have the cis-cis- , cis-cis-HT, trans-cis- , and trans-cis-HT configurations. The lack of formation of the other isomers may be due to the geometric requirements of exciplex formation. The mechanism of the reaction was established to involve initial bond formation at the 4 position of tmPso, most likely to form a diradical intermediate. The rate of dissociation of the trans diradical is much faster than ring closure, in contrast to the cis diradical whose rate of ring closure is at least as fast as dissociation. The rate of cis-trans isomerization of the 9,lO-bond of the fatty ester portion of the diradical is faster than ring closure for the cis diradical and slower than ring closure for the trans diradical

Criterion of unitary similarity for upper triangular matrices in general position

Each square complex matrix is unitarily similar to an upper triangular matrix with diagonal entries in any prescribed order. Let A and B be upper triangular n-by-n matrices that (i) are not similar to direct sums of matrices of smaller sizes, or (ii) are in general position and have the same main diagonal. We prove that A and B are unitarily similar if and only if ||h(A_k)||=||h(B_k)|| for all complex polynomials h(x) and k=1, 2, . . , n, where A_k and B_k are the principal k-by-k submatrices of A and B, and ||M|| is the Frobenius norm of M.Comment: 16 page