15,492 research outputs found
Molecular analysis and phenotype characterization of the progeny of two antisense potato plants
Two transgenic potato lines csr2-1 and csr4-8, containing two different antisense constructs, csr2 and csr4, respectively, were crossed to investigate the possibility of achieving double transformants with combined effects of the two antisense transgenes on plant phenotypes and cellulose deposition. Molecular analysis revealed an expected segregation ratio of 1:1:1:1 of the four classes. Phenotype characterization revealed that offspring containing either one or both transgenes produced more tubers than the control plants but individual tubers were mostly smaller and had lesser weight than the control tubers
Systemic inflammation: Cancer's long-distance reach to maximize metastasis
While major improvements have been made in targeting primary tumor growth, metastasis and combating cancer spread remain an enigma. We recently identified a systemic inflammatory cascade involving IL17-producing γδ T cells and neutrophils that advance breast cancer metastasis. These data provide insights into how immune cells promote cancer spread
Revving up dendritic cells while braking PD-L1 to jump-start the cancer-immunity cycle motor
Although it is successful for some, most melanoma patients are refractory to T cell checkpoint inhibition. In this issue of Immunity, Merad and colleagues (2016) describe a dendritic-cell-based strategy to heighten the efficacy of therapeutic anti-PD-L1 and BRAF inhibitors in mouse melanoma models
Applied Biotechnology to combat the late blight in potato caused by Phytophthora infestans
Potato is an important crop, grown worldwide. It suffers from many pests and diseases among which late blight, caused by the oomycete Phytophthora infestans, is the worst. The disease is still causing major damage in many potato production areas and control is only possible by applying fungicides frequently. The knowledge on the molecular biology and genetics of the interaction between the plant and the oomycete is developing rapidly. These are relevant fields of study, currently dominated by the discovery of many resistance genes and numerous effector proteins and the analysis of their specific mode of action. These studies may yield essential information needed for the development of durable resistance. The long-term and worldwide effort to breed for resistance so far has had little effect. A novel breeding approach may change this. It is based on cisgenic modification (CM) consisting of marker-free pyramiding of several resistance genes and their spatial and temporal deployment yielding dynamic varieties that contain potato genes only. It is envisioned that this CM approach with potato¿s own genes will not only prove societally acceptable but may also result in simplifications in the legislation on use of the CM approach. Various parties in the potato research arena intend to cooperate in this novel approach in a number of developing countries where potato substantially contributes to food security. The use of resources such as land, water and energy improves when the effect of late blight is markedly reduce
Differential expression of cellulose synthase (CesA) gene transcripts in potato as revealed by QRT-PCR
Two transgenic potato lines, csr2–1 and csr4–8 that contained two different antisense cellulose synthase
(CesA) genes, csr2 and csr4, respectively were crossed. The aim, amongst others, was to investigate the
possibility of generating double transformants to validate a hypothetical presence of the proteins of the
two CesA genes in the same cellulose synthase enzyme complex. SYBR-Green quantitative real-time
reverse transcription polymerase chain reaction (RT-PCR) assays were carried out on four CesA gene
transcripts (CesA1, 2, 3, and 4) in the wild type genetic background, and on the two antisense CesA gene
transcripts (CesA2 and 4) in the progeny resulting from the cross between the two transgenic potato
lines. The quantitative RT-PCR analyses revealed different expression patterns of the two CesA genes. The
CesA2 mRNA was shown to be relatively more abundant than CesA4 mRNA, regardless of the genetic
background, suggesting that the two proteins are not present in the same enzyme complex
Theorems on gravitational time delay and related issues
Two theorems related to gravitational time delay are proven. Both theorems
apply to spacetimes satisfying the null energy condition and the null generic
condition. The first theorem states that if the spacetime is null geodesically
complete, then given any compact set , there exists another compact set
such that for any , if there exists a ``fastest null
geodesic'', , between and , then cannot enter . As
an application of this theorem, we show that if, in addition, the spacetime is
globally hyperbolic with a compact Cauchy surface, then any observer at
sufficiently late times cannot have a particle horizon. The second theorem
states that if a timelike conformal boundary can be attached to the spacetime
such that the spacetime with boundary satisfies strong causality as well as a
compactness condition, then any ``fastest null geodesic'' connecting two points
on the boundary must lie entirely within the boundary. It follows from this
theorem that generic perturbations of anti-de Sitter spacetime always produce a
time delay relative to anti-de Sitter spacetime itself.Comment: 15 pages, 1 figure. Example of gauge perturbation changed/corrected.
Two footnotes added and one footnote remove
Warped space-time for phonons moving in a perfect nonrelativistic fluid
We construct a kinematical analogue of superluminal travel in the ``warped''
space-times curved by gravitation, in the form of ``super-phononic'' travel in
the effective space-times of perfect nonrelativistic fluids. These warp-field
space-times are most easily generated by considering a solid object that is
placed as an obstruction in an otherwise uniform flow. No violation of any
condition on the positivity of energy is necessary, because the effective
curved space-times for the phonons are ruled by the Euler and continuity
equations, and not by the Einstein field equations.Comment: 7 pages, 1 figure. Version as published; references update
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