Wikis and Blogs in the 21st Century Classroom (original) (raw)
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The Plant Cell, 2013
Under the endosymbiont hypothesis, over a billion years ago a heterotrophic eukaryote entered into a symbiotic relationship with a cyanobacterium (the cyanobiont). This partnership culminated in the plastid that has spread to forms as diverse as plants and diatoms. However, why primary plastid acquisition has not been repeated multiple times remains unclear. Here, we report a possible answer to this question by showing that primary plastid endosymbiosis was likely to have been primed by the secretion in the host cytosol of effector proteins from intracellular Chlamydiales pathogens. We provide evidence suggesting that the cyanobiont might have rescued its afflicted host by feeding photosynthetic carbon into a chlamydiacontrolled assimilation pathway. PERSPECTIVE 8 of 15 The Plant Cell PERSPECTIVE Figure 4. Glycogen Metabolism Putative Effectors in Extant and Ancient Chlamydiales.
Virasoro representations and fusion for general augmented minimal models
Journal of Physics A-mathematical and General, 2006
In this paper we present explicit results for the fusion of irreducible and higher rank representations in two logarithmically conformal models, the augmented c 2,3 = 0 model as well as the augmented Yang-Lee model at c 2,5 = −22/5. We analyse their spectrum of representations which is consistent with the symmetry and associativity of the fusion algebra. We also describe the first few higher rank representations in detail. In particular, we present the first examples of consistent rank 3 indecomposable representations and describe their embedding structure.
Fish & Shellfish Immunology, 2008
RNA interference (RNAi) is an evolutionarily conserved mechanism by which double-stranded RNA (dsRNA) initiates post-transcriptional silencing of homologous genes. Here we report the amplification and characterisation of a full length cDNA from black tiger shrimp (Penaeus monodon) that encodes the bidentate RNAase III Dicer, a key component of the RNAi pathway. The full length of the shrimp Dicer (Pm Dcr1) cDNA is 7629 bp in length, including a 5 0 untranslated region (UTR) of 130 bp, a 3 0 UTR of 77 bp, and an open reading frame of 7422 bp encoding a polypeptide of 2473 amino acids with an estimated molecular mass of 277.895 kDa and a predicted isoelectric point of 4.86. Analysis of the deduced amino acid sequence indicated that the mature peptide contains all the seven recognised functional domains and is most similar to the mosquito (Aedes aegypti) Dicer-1 sequence with a similarity of 34.6%. Quantitative RTePCR analysis showed that Pm Dcr1 mRNA is most highly expressed in haemolymph and lymphoid organ tissues (P < 0.05). However, there was no correlation between Pm Dcr1 mRNA levels in lymphoid organ and the viral genetic loads in shrimp naturally infected with gill-associated virus (GAV) and Mourilyan virus (P > 0.05). Treatment with synthetic dsRNA corresponding to Pm Dcr1 sequence resulted in knock-down of Pm Dcr1 mRNA expression in both uninfected shrimp and shrimp infected experimentally with GAV. Knock-down of Pm Dcr1 expression resulted in more rapid mortalities and higher viral loads. These data demonstrated that Dicer is involved in antiviral defence in shrimp. ª
Rigidity of non-negatively curved metrics on open five-dimensional manifolds
2004
As the first step in the direction of the Hopf conjecture on the non-existence of metrics with positive sectional curvature on S2timesS2S^2 \times S^2S2timesS2 D.Gromoll and K.Tapp in [GT] suggested the following (Weak Hopf) conjecture (on the rigidity of non-negatively curved metrics on S2timesR3S^2 \times R^3S2timesR3): "The boundary S2timesS2S^2\times S^2S2timesS2 of the S2timesB3subsetS2timesR3S^2 \times B^3\subset S^2 \times R^3S2timesB3subsetS2timesR3 with an arbitrary complete metric of non-negative sectional curvature contains a point where a curvature of S2timesS2S^2 \times S^2S2timesS2 vanish". In this note we verify this.
Geodesics in stationary spacetimes. Application to Kerr spacetime
2001
The Levi-Civita connection and geodesic equations for a stationary spacetime are studied in depth. General formulae which generalize those for warped products are obtained. These results are applicated to some regions of Kerr spacetime previously studied by using variational methods. We show that they are neither space-convex nor geodesically connected. Moreover, the whole stationary part of Kerr spacetime is not geodesically connected, except when the angular momentum is equal to zero (Schwarzschild spacetime).
Conservation of mass -Mass -density Newton's second law -Momentum -velocity The first law of thermodynamics -internal energy -temperature 1.2 a) density = mass/volume = M L / 3 b) pressure = force/area = F L ML T L M LT / / / 2 2 2 2 − =×=− 2.16 Use the result of Example 2.2: p = 101 e −gz/RT . a) p = 101 e −9.81 ×10 000/287 ×273 = 28.9 kPa. b) p = 101 e −9.81 ×10 000/287 ×288 = 30.8 kPa. c) p = 101 e −9.81 ×10 000/287 ×258 = 26.9 kPa. 2.17 Use Eq. 2.4.8: p = 9.81 0.0065287 101(10.0065/288). z × − a) z = 3000. ∴p = 69.9 kPa. b) z = 6000. ∴p = 47.0 kPa. c) z = 9000. ∴p = 30.6 kPa. d) z = 11 000. ∴p = 22.5 kPa.