494 research outputs found
Creating contacts between replication and movement at plasmodesmata – a role for membrane contact sites in plant virus infections?
Parts of this work were funded by the University of Florida, Institute of Food and Agricultural Sciences, Early Career Seed Grant No. 00127818 to AL and by the UK Biotechnology and Biomedical Sciences Research Council (BBSRC) grant BB/M007200/1 to JT.To infect their hosts and cause disease, plant viruses must replicate within cells and move throughout the plant both locally and systemically. RNA virus replication occurs on the surface of various cellular membranes, whose shape and composition become extensively modified in the process. Membrane contact sites (MCS) can mediate non-vesicular lipid-shuttling between different membranes and viruses co-opt components of these structures to make their membrane environment suitable for replication. Whereas animal viruses exit and enter cells when moving throughout their host, the rigid wall of plant cells obstructs this pathway and plant viruses therefore move between cells symplastically through plasmodesmata (PD). PD are membranous channels connecting nearly all plant cells and are now viewed to constitute a specialized type of endoplasmic reticulum (ER)-plasma membrane (PM) MCS themselves. Thus, both replication and movement of plant viruses rely on MCS. However, recent work also suggests that for some viruses, replication and movement are closely coupled at ER-PM MCS at the entrances of PD. Movement-coupled replication at PD may be distinct from the main bulk of replication and virus accumulation, which produces progeny virions for plant-to-plant transmission. Thus, MCS play a central role in plant virus infections, and may provide a link between two essential steps in the viral life cycle, replication and movement. Here, we provide an overview of plant virus-MCS interactions identified to date, and place these in the context of the connection between viral replication and cell-to-cell movement.Publisher PDFPeer reviewe
Charge-Inhomogeneity doping relations in YBCO detected by Angle Dependent Nuclear Quadrupole Resonance
The origin of charge inhomogeneity in YBa_{2}Cu_{3}O_{y} is investigated
using a new experimental method designed to determine the nuclear quadrupole
resonance (NQR) asymmetry parameter eta for very wide NQR lines at different
positions on the line. The method is based on the measurement of the echo
intensity as a function of the angle between the radio frequency field H1 and
the principal axis of the electric field gradient. Static charge inhomogeneity
deduced from eta>0 are found in this compound, but only in conjunction with
oxygen deficiency. This limits considerably the possible forms of charge
inhomogeneity in bulk YBa_{2}Cu_{3}O_{y}.Comment: To be published in Phys. Rev. B; Revised version with a correction to
figure
Transpose Attack: Stealing Datasets with Bidirectional Training
Deep neural networks are normally executed in the forward direction. However,
in this work, we identify a vulnerability that enables models to be trained in
both directions and on different tasks. Adversaries can exploit this capability
to hide rogue models within seemingly legitimate models. In addition, in this
work we show that neural networks can be taught to systematically memorize and
retrieve specific samples from datasets. Together, these findings expose a
novel method in which adversaries can exfiltrate datasets from protected
learning environments under the guise of legitimate models. We focus on the
data exfiltration attack and show that modern architectures can be used to
secretly exfiltrate tens of thousands of samples with high fidelity, high
enough to compromise data privacy and even train new models. Moreover, to
mitigate this threat we propose a novel approach for detecting infected models.Comment: NDSS24 pape
Opto-thermal transport engineering in hybrid organic-inorganic lead halide perovskites metasurfaces
Halide perovskites have recently gained widespread attention for their
exceptional optoelectronic properties which have been illuminated by extensive
spectroscopic investigations. In this article, nanophotonic surface-engineering
using soft-lithography has been used to reproduce nanostructures with enhanced
functionalities. A non-invasive optical technique based on Raman and
photolumines-cence (PL) spectroscopy is employed to investigate the interactive
effect of the thermal and optical behaviour in surface-patterned hybrid
organic-inorganic halide perovskite thin films. The thermophys-ical properties
of the engineered perovskite films are extracted from the softening of the
representa-tive peak positions in the Raman and PL spectra of the samples which
act as temperature markers. The investigation suggests a comparatively higher
rise in the local temperature for the patterned thin films resulting from their
enhanced absorption. Therefore, a cross-talk between the opto-thermal transport
phenomena in imprinted perovskite thin films pertaining to both enhancing
device properties along with maintaining device stability is established
Leaders and Non-leaders: A Comparative Study of Some Major Developmental Aspects
The research presented here is based on the assumption that there are unique features in the development of leaders in social and organizational settings. Fifty Israeli soldiers who were perceived as leaders by their commanders and peers were compared with 30 soldiers who received low scores on leadership evaluations. The participants were selected out of a group of 286 soldiers on a combat training course. Differences were found between those perceived as leaders and those who scored low on leadership evaluations, in developmental aspects such as relations in the family, expectations transmitted to them by the family, exposure to models of leadership, experiences of leadership roles in social frameworks, and openness to experiences
A rapid, inexpensive, and semi-quantitative method for determining pollen tube extension using fluorescence
BACKGROUND: Pollen tubes extend rapidly when pollen grains are incubated in defined media. Tube extension requires many critical functions of plant cells including molecular signaling, cytoskeleton remodeling, secretion, and cell wall synthesis. Consequently, pollen tube growth has been established as a way to conduct primary screens of chemical libraries to identify compounds that perturb key cellular processes in plants. RESULTS: Here we report a simple, inexpensive, rapid and semi-quantitative method for measurement of pollen tube growth in microtiter plates. The method relies on Congo Red binding to pollen tubes and correlates dye fluorescence to tube length. CONCLUSIONS: This method can be used in any laboratory without specialized equipment, and has the potential to enable larger screens as chemical libraries grow and to make chemical screening accessible to researchers building specialized libraries designed to probe pathways in plant biology
- …