620 research outputs found
Cancer, Fertility Preservation, and Future Pregnancy: A Comprehensive Review
Given the increases in 5-year cancer survival and recent advances in fertility preserving technologies, an increasing number of women with cancer are presenting for discussion of fertility preserving options. This review will summarize the risk of infertility secondary to cancer treatment, available treatment options for fertility preservation, and techniques to reduce future risks for patients. Concerns that will be addressed include the risk of the medications and procedures, the potential delay in cancer treatment, likelihood of pregnancy complications, as well as the impact of future pregnancy on the recurrence risk of cancer. Recent advances in oocyte cryopreservation and ovarian stimulation protocols will be discussed. Healthcare providers need to be informed of available treatment options including the risks, advantages, and disadvantages of fertility preserving options to properly counsel patients
Stochastic Cellular Automata Model for Stock Market Dynamics
In the present work we introduce a stochastic cellular automata model in
order to simulate the dynamics of the stock market. A direct percolation method
is used to create a hierarchy of clusters of active traders on a two
dimensional grid. Active traders are characterised by the decision to buy,
(+1), or sell, (-1), a stock at a certain discrete time step. The remaining
cells are inactive,(0). The trading dynamics is then determined by the
stochastic interaction between traders belonging to the same cluster. Most of
the stylized aspects of the financial market time series are reproduced by the
model.Comment: 17 pages and 7 figure
Brain glucose sensors play a significant role in the regulation of pancreatic glucose-stimulated insulin secretion.
As patients decline from health to type 2 diabetes, glucose-stimulated insulin secretion (GSIS) typically becomes impaired. Although GSIS is driven predominantly by direct sensing of a rise in blood glucose by pancreatic β-cells, there is growing evidence that hypothalamic neurons control other aspects of peripheral glucose metabolism. Here we investigated the role of the brain in the modulation of GSIS. To examine the effects of increasing or decreasing hypothalamic glucose sensing on glucose tolerance and insulin secretion, glucose or inhibitors of glucokinase, respectively, were infused into the third ventricle during intravenous glucose tolerance tests (IVGTTs). Glucose-infused rats displayed improved glucose handling, particularly within the first few minutes of the IVGTT, with a significantly lower area under the excursion curve within the first 10 min (AUC0-10). This was explained by increased insulin secretion. In contrast, infusion of the glucokinase inhibitors glucosamine or mannoheptulose worsened glucose tolerance and decreased GSIS in the first few minutes of IVGTT. Our data suggest a role for brain glucose sensors in the regulation of GSIS, particularly during the early phase. We propose that pharmacological agents targeting hypothalamic glucose-sensing pathways may represent novel therapeutic strategies for enhancing early phase insulin secretion in type 2 diabetes
S-acylation stabilizes ligand-induced receptor kinase complex formation during plant pattern-triggered immune signalling
SummaryPlant receptor kinases are key transducers of extracellular stimuli, such as the presence of beneficial or pathogenic microbes or secreted signalling molecules. Receptor kinases are regulated by numerous post-translational modifications. Here, using the immune receptor kinases FLS2 and EFR, we show that S-acylation at a cysteine conserved in all plant receptor kinases is crucial for function. S-acylation involves the addition of long-chain fatty acids to cysteine residues within proteins, altering their biophysical properties and behaviour within the membrane environment. We observe S-acylation of FLS2 at C-terminal kinase domain cysteine residues within minutes following perception of its ligand flg22, in a BAK1 co-receptor dependent manner. We demonstrate that S-acylation is essential for FLS2-mediated immune signalling and resistance to bacterial infection. Similarly, mutating the corresponding conserved cysteine residue in EFR supressed elf18 triggered signalling. Analysis of unstimulated and activated FLS2-containing complexes using microscopy, detergents and native membrane DIBMA nanodiscs indicates that S-acylation stabilises and promotes retention of activated receptor kinase complexes at the plasma membrane to increase signalling efficiency
S-acylation stabilizes ligand-induced receptor kinase complex formation during plant pattern-triggered immune signaling
Plant receptor kinases are key transducers of extracellular stimuli, such as the presence of beneficial or pathogenic microbes or secreted signaling molecules. Receptor kinases are regulated by numerous post-translational modifications.1,2,3 Here, using the immune receptor kinases FLS24 and EFR,5 we show that S-acylation at a cysteine conserved in all plant receptor kinases is crucial for function. S-acylation involves the addition of long-chain fatty acids to cysteine residues within proteins, altering their biochemical properties and behavior within the membrane environment.6 We observe S-acylation of FLS2 at C-terminal kinase domain cysteine residues within minutes following the perception of its ligand, flg22, in a BAK1 co-receptor and PUB12/13 ubiquitin ligase-dependent manner. We demonstrate that S-acylation is essential for FLS2-mediated immune signaling and resistance to bacterial infection. Similarly, mutating the corresponding conserved cysteine residue in EFR suppressed elf18-triggered signaling. Analysis of unstimulated and activated FLS2-containing complexes using microscopy, detergents, and native membrane DIBMA nanodiscs indicates that S-acylation stabilizes, and promotes retention of, activated receptor kinase complexes at the plasma membrane to increase signaling efficiency
Efficient photoionization for barium ion trapping using a dipole-allowed resonant two-photon transition
Two efficient and isotope-selective resonant two-photon ionization techniques
for loading barium ions into radio-frequency (RF)-traps are demonstrated. The
scheme of using a strong dipole-allowed transition at \lambda=553 nm as a first
step towards ionization is compared to the established technique of using a
weak intercombination line (\lambda=413 nm). An increase of two orders of
magnitude in the ionization efficiency is found favoring the transition at 553
nm. This technique can be implemented using commercial all-solid-state laser
systems and is expected to be advantageous compared to other narrowband
photoionization schemes of barium in cases where highest efficiency and
isotope-selectivity are required.Comment: 8 pages, 5 figure
Whole-genome analysis of Exserohilum rostratum from an outbreak of fungal meningitis and other infections
Exserohilum rostratum was the cause of most cases of fungal meningitis and other infections associated with the injection of contaminated methylprednisolone acetate produced by the New England Compounding Center (NECC). Until this outbreak, very few human cases of Exserohilum infection had been reported, and very little was known about this dematiaceous fungus, which usually infects plants. Here, we report using whole-genome sequencing (WGS) for the detection of single nucleotide polymorphisms (SNPs) and phylogenetic analysis to investigate the molecular origin of the outbreak using 22 isolates of E. rostratum retrieved from 19 case patients with meningitis or epidural/spinal abscesses, 6 isolates from contaminated NECC vials, and 7 isolates unrelated to the outbreak. Our analysis indicates that all 28 isolates associated with the outbreak had nearly identical genomes of 33.8 Mb. A total of 8 SNPs were detected among the outbreak genomes, with no more than 2 SNPs separating any 2 of the 28 genomes. The outbreak genomes were separated from the next most closely related control strain by ∼136,000 SNPs. We also observed significant genomic variability among strains unrelated to the outbreak, which may suggest the possibility of cryptic speciation in E. rostratum
Search for the exotic Resonance in 340GeV/c -Nucleus Interactions
We report on a high statistics search for the resonance in
-nucleus collisions at 340GeV/c. No evidence for this resonance is
found in our data sample which contains 676000 candidates above
background. For the decay channel and the
kinematic range 0.150.9 we find a 3 upper limit for the
production cross section of 3.1 and 3.5 b per nucleon for reactions with
carbon and copper, respectively.Comment: 5 pages, 4 figures, modification of ref. 43 and 4
Measurement of the Omega_c Lifetime
We present the measurement of the lifetime of the Omega_c we have performed
using three independent data samples from two different decay modes. Using a
Sigma- beam of 340 GeV/c we have obtained clean signals for the Omega_c
decaying into Xi- K- pi+ pi+ and Omega- pi+ pi- pi+, avoiding topological cuts
normally used in charm analysis. The short but measurable lifetime of the
Omega_c is demonstrated by a clear enhancement of the signals at short but
finite decay lengths. Using a continuous maximum likelihood method we
determined the lifetime to be tau(Omega_c) = 55 +13-11(stat) +18-23(syst) fs.
This makes the Omega_c the shortest living weakly decaying particle observed so
far. The short value of the lifetime confirms the predicted pattern of the
charmed baryon lifetimes and demonstrates that the strong interaction plays a
vital role in the lifetimes of charmed hadrons.Comment: 15 pages, including 7 figures; gzipped, uuencoded postscrip
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