723 research outputs found
The resonant B1II+B1II binary BI108
BI108 is a luminous variable star in the Large Magellanic Cloud classified
B1II. The variability consists of two resonant periods (3:2), of which only one
is orbital, however. We discuss possible mechanisms responsible for the second
period and its resonant locking.Comment: 2 pages, 1 figure, IAUS 272 - Active OB Stars: Structure, Evolution,
Mass Loss and Critical Limit
Impact of lattice dynamics on the phase stability of metamagnetic FeRh: Bulk and thin films
We present phonon dispersions, element-resolved vibrational density of states
(VDOS) and corresponding thermodynamic properties obtained by a combination of
density functional theory (DFT) and nuclear resonant inelastic X-ray scattering
(NRIXS) across the metamagnetic transition of B2 FeRh in the bulk material and
thin epitaxial films. We see distinct differences in the VDOS of the
antiferromagnetic (AF) and ferromagnetic (FM) phase which provide a microscopic
proof of strong spin-phonon coupling in FeRh. The FM VDOS exhibits a particular
sensitivity to the slight tetragonal distortions present in epitaxial films,
which is not encountered in the AF phase. This results in a notable change in
lattice entropy, which is important for the comparison between thin film and
bulk results. Our calculations confirm the recently reported lattice
instability in the AF phase. The imaginary frequencies at the -point depend
critically on the Fe magnetic moment and atomic volume. Analyzing these non
vibrational modes leads to the discovery of a stable monoclinic ground state
structure which is robustly predicted from DFT but not verified in our thin
film experiments. Specific heat, entropy and free energy calculated within the
quasiharmonic approximation suggest that the new phase is possibly suppressed
because of its relatively smaller lattice entropy. In the bulk phase, lattice
degrees of freedom contribute with the same sign and in similar magnitude to
the isostructural AF-FM phase transition as the electronic and magnetic
subsystems and therefore needs to be included in thermodynamic modeling.Comment: 15 pages, 12 figure
Experiences from treating seven adult 5q spinal muscular atrophy patients with Nusinersen
Background: The antisense oligonucleotide Nusinersen recently became the first approved drug against spinal muscular atrophy (SMA). It was approved for all ages, albeit the clinical trials were conducted exclusively on children. Hence, clinical data on adults being treated with Nusinersen is scarce. In this case series, we report on drug application, organizational demands, and preliminary effects during the first 10 months of treatment with Nusinersen in
seven adult patients.
Methods: All patients received intrathecal injections with Nusinersen. In cases with severe spinal deformities, we performed computed tomography (CT)-guided applications. We conducted a total of 40 administrations of Nusinersen. We evaluated the patients with motor, pulmonary, and laboratory assessments, and tracked patient-reported outcome.
Results: Intrathecal administration of Nusinersen was successful in most patients, even though access to the lumbar intrathecal space in adults with SMA is often challenging. No severe adverse events occurred. Six of the seven patients reported stabilization of motor function or reduction in symptom severity. The changes in the assessed scores did not reach a
significant level within this short time period.
Conclusions: Treating adult SMA patients with Nusinersen is feasible and most patients consider it beneficial. It demands a complex organizational and interdisciplinary effort. Due to the slowly decreasing motor functions in adult SMA patients, long observation phases for this recently approved treatment are needed to allow conclusions about effectiveness of Nusinersen in adults
Calcium Influx through Plasma-Membrane Nanoruptures Drives Axon Degeneration in a Model of Multiple Sclerosis
Axon loss determines persistent disability in multiple sclerosis patients. Here, we use in vivo calcium imaging in a multiple sclerosis model to show that cytoplasmic calcium levels determine the choice between axon loss and survival. We rule out the endoplasmic reticulum, glutamate excitotoxicity, and the reversal of the sodium-calcium exchanger as sources of intra-axonal calcium accumulation and instead identify nanoscale ruptures of the axonal plasma membrane as the critical path of calcium entry
Density of neutral interstellar hydrogen at the termination shock from Ulysses pickup ion observations
By reevaluating a 13-month stretch of Ulysses SWICS H pickup ion measurements
near 5 AU close to the ecliptic right after the previous solar minimum, this
paper presents a determination of the neutral interstellar H density at the
solar wind termination shock and implications for the density and ionization
degree of hydrogen in the LIC. The density of neutral interstellar hydrogen at
the termination shock was determined from the local pickup ion production rate
as obtained close to the cut-off in the distribution function at aphelion of
Ulysses. As shown in an analytical treatment for the upwind axis and through
kinetic modeling of the pickup ion production rate at the observer location,
with variations in the ionization rate, radiation pressure, and the modeling of
the particle behavior, this analysis turns out to be very robust against
uncertainties in these parameters and the modeling. Analysis using current
heliospheric parameters yields the H density at the termination shock equal to
cm, including observational and modeling uncertainties.Comment: Re-edited version, density revised downward due to data
re-processing, accepted by A&
An Unexplained 10 Degree - 40 Degree Shift in the Location of Some Diverse Neutral Atom Data at 1 AU
Four different data sets pertaining to the neutral atom environment at 1 AU
are presented and discussed. These data sets include neutral solar wind and
interstellar neutral atom data from IMAGE/LENA, energetic hydrogen atom data
from SOHO/HSTOF and plasma wave data from the magnetometer on ISEE-3.
Surprisingly, these data sets are centered between 262 degrees and 292 degrees
ecliptic longitude, about 10 degrees - 40 degrees from the upstream
interstellar neutral flow direction at 254 degrees resulting from the motion of
the Sun relative to the local interstellar cloud. Some possible explanations
for this offset, none of which is completely satisfactory, are discussed.Comment: 6 pages, 6 figures, 2 color peer-reviewed paper, in press, COSPAR/WS
Transcriptomic and Exometabolomic Profiling Reveals Antagonistic and Defensive Modes of Clonostachys rosea Action Against Fusarium graminearum
The mycoparasite Clonostachys rosea ACM941 is under development as a biocontrol organism against Fusarium graminearum, the causative agent of Fusarium head blight in cereals. To identify molecular factors associated with this interaction, the transcriptomic and exometabolomic profiles of C. rosea and F. graminearum GZ3639 were compared during coculture. Prior to physical contact, the antagonistic activity of C. rosea correlated with a response heavily dominated by upregulation of polyketide synthase gene clusters, consistent with the detected accumulation of corresponding secondary metabolite products. Similarly, prior to contact, trichothecene gene clusters were upregulated in F. graminearum, while those responsible for fusarielin and fusarin biosynthesis were downregulated, correlating with an accumulation of trichothecene products in the interaction zone over time. A concomitant increase in 15-acetyl deoxynivalenol-3-glucoside in the interaction zone was also detected, with C. rosea established as the source of this detoxified mycotoxin. After hyphal contact, C. rosea was found to predominantly transcribe genes encoding cell wall–degradation enzymes, major facilitator superfamily sugar transporters, anion:cation symporters, as well as alternative carbon source utilization pathways, together indicative of a transition to necrotropism at this stage. F. graminearum notably activated the transcription of phosphate starvation pathway signature genes at this time. Overall, a number of signature molecular mechanisms likely contributing to antagonistic activity by C. rosea against F. graminearum, as well as its mycotoxin tolerance, are identified in this report, yielding several new testable hypotheses toward understanding the basis of C. rosea as a biocontrol agent for continued agronomic development and application
Neutral H density at the termination shock: a consolidation of recent results
We discuss a consolidation of determinations of the density of neutral
interstellar H at the nose of the termination shock carried out with the use of
various data sets, techniques, and modeling approaches. In particular, we focus
on the determination of this density based on observations of H pickup ions on
Ulysses during its aphelion passage through the ecliptic plane. We discuss in
greater detail a novel method of determination of the density from these
measurements and review the results from its application to actual data. The H
density at TS derived from this analysis is equal to 0.087 \pm 0.022 cm-3, and
when all relevant determinations are taken into account, the consolidated
density is obtained at 0.09 \pm 0.022 cm-3. The density of H in CHISM based on
literature values of filtration factor is then calculated at 0.16 \pm 0.04
cm-3.Comment: Submitted to Space Science Review
Clonal karyotype evolution involving ring chromosome 1 with myelodysplastic syndrome subtype RAEB-t progressing into acute leukemia
s Karyotypic evolution is a well-known phenomenon in patients with malignant hernatological disorders during disease progression. We describe a 50-year-old male patient who had originally presented with pancytopenia in October 1992. The diagnosis of a myelodysplastic syndrome (MDS) FAB subtype RAEB-t was established in April 1993 by histological bone marrow (BM) examination, and therapy with low-dose cytosine arabinoside was initiated. In a phase of partial hernatological remission, cytogenetic assessment in August 1993 revealed a ring chromosome 1 in 13 of 21 metaphases beside BM cells with normal karyotypes {[}46,XY,r(1)(p35q31)/46,XY]. One month later, the patient progressed to an acute myeloid leukemia (AML), subtype M4 with 40% BM blasts and cytogenetic examination showed clonal evolution by the appearance of additional numerical aberrations in addition to the ring chromosome{[}46,XY,r(1),+8,-21/45,XY,r(1),+8,-21,-22/46, XY]. Intensive chemotherapy and radiotherapy was applied to induce remission in preparation for allogeneic bone marrow transplantation (BMT) from the patient's HLA-compatible son. After BMT, complete remission was clinically, hematologically and cytogenetically (normal male karyotype) confirmed. A complete hematopoietic chimerism was demonstrated. A relapse in January 1997 was successfully treated using donor lymphocyte infusion and donor peripheral blood stem cells (PB-SC) in combination with GM-CSF as immunostimulating agent in April 1997, and the patient's clinical condition remained stable as of January 2005. This is an interesting case of a patient with AML secondary to MDS. With the ring chromosome 1 we also describe a rare cytogenetic abnormality that predicted the poor prognosis of the patient, but the patient could be cured by adoptive immunotherapy and the application of donor's PB-SC. This case confirms the value of cytogenetic analysis in characterizing the malignant clone in hernatological neoplasias, the importance of controlling the quality of an induced remission and of the detection of a progress of the disease. Copyright (c) 2006 S. Karger AG, Basel
Reduced functional measure of cardiovascular reserve predicts admission to critical care unit following kidney transplantation
Background: There is currently no effective preoperative assessment for patients undergoing kidney transplantation that is
able to identify those at high perioperative risk requiring admission to critical care unit (CCU). We sought to determine if
functional measures of cardiovascular reserve, in particular the anaerobic threshold (VO2AT) could identify these patients.
Methods: Adult patients were assessed within 4 weeks prior to kidney transplantation in a University hospital with a 37-bed
CCU, between April 2010 and June 2012. Cardiopulmonary exercise testing (CPET), echocardiography and arterial
applanation tonometry were performed.
Results: There were 70 participants (age 41.7614.5 years, 60% male, 91.4% living donor kidney recipients, 23.4% were
desensitized). 14 patients (20%) required escalation of care from the ward to CCU following transplantation. Reduced
anaerobic threshold (VO2AT) was the most significant predictor, independently (OR = 0.43; 95% CI 0.27–0.68; p,0.001) and
in the multivariate logistic regression analysis (adjusted OR = 0.26; 95% CI 0.12–0.59; p = 0.001). The area under the receiveroperating-
characteristic curve was 0.93, based on a risk prediction model that incorporated VO2AT, body mass index and
desensitization status. Neither echocardiographic nor measures of aortic compliance were significantly associated with CCU
admission.
Conclusions: To our knowledge, this is the first prospective observational study to demonstrate the usefulness of CPET as a
preoperative risk stratification tool for patients undergoing kidney transplantation. The study suggests that VO2AT has the
potential to predict perioperative morbidity in kidney transplant recipients
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