GhMYC1374 regulates the cotton defense response to cotton aphids by mediating the production of flavonoids and free gossypol.

Myelocytomatosis (MYC) transcription factors (TFs) in plants are well-known regulators of plant defense against herbivores. However, the role and mechanism of MYC TFs in cotton (Gossypium hirsutum L.) defense against cotton aphids (Aphis gossypii Glover) remain still elusive. Herein, on the basis of aphid-induced cotton transcriptome analysis, GhMYC1374, a cotton MYC2-like TF that was highly induced by cotton aphid attack, has been identified that confers cotton aphid resistance in cotton. GhMYC1374 was an intranuclear transcription factor with three domains: bHLH-MYC_N, RBR and bHLH_AtAIB_like. GhMYC1374 was induced under cotton aphid feeding, exogenous methyl jasmonate (MeJA) and salicylic acid (SA) treatments. GhMYC1374 transient overexpression in cotton plants enhanced cotton aphid-resistance, while GhMYC1374 silence through VIGS (virus induced gene silencing) decreased cotton aphid-resistance. GhMYC1374 transient overexpression of in cotton plants activated the phenylpropane pathway and promoted the synthesis of flavonoids, and resistance to thus enhanced the cotton resistance against aphids. In contrast, GhMYC1374 silence inhibited the biosynthesis of flavonoids. In addition, GhMYC1374 also positively activated the expression of the biosynthetic genes of free gossypol, leading to the high content of free gossypol. Taken together, our results suggest that GhMYC1374 is involved in the cotton defense response against cotton aphids by regulating the biosynthesis of flavonoids and free gossypol.

Hardware-efficient blind frequency offset estimation for digital subcarrier multiplexing signals.

Since the frequency offset estimation (FOE) must be implemented before the subcarrier de-multiplexing and chromatic dispersion compensation (CDC) for digital subcarrier multiplexing (DSM) signals, traditional FOE algorithms for single carrier transmission is no longer suitable. Here, we propose a hardware-efficient blind FOE solution for the DSM signals by monitoring spectral dips in the frequency domain. With the use of a smoothing filter, the estimation accuracy of FOE can be significantly increased. Moreover, we identify that the proposed FOE method is robust to various transmission impairments, including amplified spontaneous emission (ASE) noise, optical filtering, and fiber nonlinearity. The effective function of the proposed FOE method is numerically and experimentally verified under scenarios of both back-to-back (B2B) and the 2560 km standard single-mode fiber (SSMF) transmission, leading to a FOE error less than 100 MHz with a FFT size of 1024.

Inter-ring and endo anomeric effects, and hydrogen-bonded supramolecular motifs in two 2,4,6,8-tetraazabicyclo[3.3.0]octane derivatives.

In 2,4,6,8-tetrakis(4-chlorophenyl)-2,4,6,8-tetraazabicyclo[3.3.0]octane, C(28)H(22)Cl(4)N(4), the imidazolidine rings adopt envelope conformations, which are favoured by two equal endo anomeric effects. The molecule lies on a crystallographic twofold axis and molecules are linked into a three-dimensional framework via two C-H...Cl hydrogen bonds. In 2,4,6,8-tetrakis(4-methoxyphenyl)-2,4,6,8-tetraazabicyclo[3.3.0]octane, C(32)H(34)N(4)O(4), one of the methyl groups is disordered over two sets of sites and the same methyl group participates in an intermolecular C-H...O hydrogen bond, which in turn causes a considerable deviation from the preferred conformation. There are two unequal inter-ring anomeric effects in the N-C-N groups. Molecules are linked into corrugated sheets by one C-H...pi hydrogen bond and two independent C-H...O hydrogen bonds involving methoxy groups.

Safety and immunogenicity of Escherichia coli O157 O-specific polysaccharide conjugate vaccine in 2-5-year-old children.

BACKGROUND: Escherichia coli O157:H7 causes severe enteritis and hemolytic-uremic syndrome, mostly in young children and older adults. Similar to the case with Shigella, serum IgG against the O-specific polysaccharide of E. coli O157:H7 may confer immunity by lysing the inoculum in the intestine. A phase 1 trial in adults showed that a vaccine of E. coli O157:H7 O-specific polysaccharide conjugated to recombinant exotoxin A of Pseudomonas aeruginosa (O157-rEPA) was safe and immunogenic. METHODS: A phase 2 trial of the O157-rEPA vaccine was conducted in 49 children 2-5 years old who were divided randomly into groups receiving 1 or 2 doses of vaccine. Adverse reactions were monitored. Serum IgG lipopolysaccharide (LPS) antibodies were determined. RESULTS: No significant adverse reactions were observed. At 1 week after the first dose was administered, most children (81%) responded with a >4-fold increase in serum IgG LPS antibodies. At 6 weeks after the first dose was administered, all children responded with a >8-fold increase; a second dose did not elicit a booster response. At 26 weeks after the first dose was administered, the geometric mean titer of serum IgG LPS antibodies was ~20-fold higher than was the prevaccination titer. These serum samples had high titers of bactericidal activity that were correlated roughly with serum IgG LPS antibody titers (r = .78). CONCLUSIONS: The O157-rEPA vaccine was safe and immunogenic in young children. A phase 3 trial of the administration of this conjugate vaccine concurrently with routine immunization in infants is planned.