530 research outputs found
Grapevine leafroll-associated virus 3.
Grapevine leafroll disease (GLD) is one of the most important grapevine viral diseases affecting grapevines worldwide. The impact on vine health, crop yield, and quality is difficult to assess due to a high number of variables, but significant economic losses are consistently reported over the lifespan of a vineyard if intervention strategies are not implemented. Several viruses from the family Closteroviridae are associated with GLD. However, Grapevine leafroll-associated virus 3 (GLRaV-3), the type species for the genus Ampelovirus, is regarded as the most important causative agent. Here we provide a general overview on various aspects of GLRaV-3, with an emphasis on the latest advances in the characterization of the genome. The full genome of several isolates have recently been sequenced and annotated, revealing the existence of several genetic variants. The classification of these variants, based on their genome sequence, will be discussed and a guideline is presented to facilitate future comparative studies. The characterization of sgRNAs produced during the infection cycle of GLRaV-3 has given some insight into the replication strategy and the putative functionality of the ORFs. The latest nucleotide sequence based molecular diagnostic techniques were shown to be more sensitive than conventional serological assays and although ELISA is not as sensitive it remains valuable for high-throughput screening and complementary to molecular diagnostics. The application of next-generation sequencing is proving to be a valuable tool to study the complexity of viral infection as well as plant pathogen interaction. Next-generation sequencing data can provide information regarding disease complexes, variants of viral species, and abundance of particular viruses. This information can be used to develop more accurate diagnostic assays. Reliable virus screening in support of robust grapevine certification programs remains the cornerstone of GLD management
Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture II: Intermediate Scattering Function and Dynamic Susceptibility
We have performed a molecular dynamics computer simulation of a supercooled
binary Lennard-Jones system in order to compare the dynamical behavior of this
system with the predictions of the idealized version of mode-coupling theory
(MCT). By scaling the time by the temperature dependent -relaxation
time , we find that in the -relaxation regime and
, the coherent and incoherent intermediate scattering functions, for
different temperatures each follows a -dependent master curve as a function
of scaled time. We show that during the early part of the -relaxation,
which is equivalent to the late part of the -relaxation, these master
curves are well approximated by the master curve predicted by MCT for the
-relaxation. This part is also fitted well by a power-law, the so-called
von Schweidler law. We show that the effective exponent of this power-law
depends on the wave vector if is varied over a large range. The early
part of the -relaxation regime does not show the critical decay
predicted by MCT. The -dependence of the nonergodicity parameter for
and are in qualitative agreement with MCT. On the time
scale of the late -relaxation the correlation functions show a
Kohlrausch-Williams-Watt behavior (KWW). The KWW exponent is
significantly different from the effective von Schweidler exponent . At low
temperatures the -relaxation time shows a power-law behavior
with a critical temperature that is the same as the one found previously for
the diffusion constant [Phys. Rev. Lett. {\bf 73}, 1376 (1994)]. The critical
exponent of this power-law and the von Schweidler exponent fulfill the
connection proposed by MCT between these two quantities. We also show that theComment: 28 Pages of REVTEX, Figures available from W. Ko
Allergologische Diagnostik von Überempfindlichkeitsreaktionen auf Arzneimittel
Überempfindlichkeitsreaktionen auf Arzneimittel müssen ausreichend geklärt werden mit dem Ziel, den Auslöser zu identifizieren. Die Anamnese umfasst neben der allgemeinen Anamnese auch Informationen zu angewandten Arzneimitteln, zur Klassifikation und zu den Umständen der Reaktion. Hauttests erfolgen bei allen Reaktionen mit Symptomen allergischer Überempfindlichkeiten mit geeigneten Testkonzentrationen, möglichst zwischen 4 Wochen und 6 Monate nach Abheilung der Reaktion durch Pricktest, Intrakutantest, Epikutantest oder Photopatchtest. Validierte Tests zum Nachweis spezifischer IgE-Antikörper im Serum sind nur für wenige Arzneistoffe (vor allem Betalaktamantibiotika) verfügbar; andere immunologische Labormethoden, z.B. der Basophilen-Aktivierungstest, werden nur in ausgewählten Fällen angewendet. Provokationstests sind indiziert, wenn der Auslöser durch bisherige Untersuchungen nicht mit Sicherheit identifiziert werden kann. Die Bewertung der Ergebnisse von Provokationstests sollte möglichst anhand objektiver Parameter erfolgen. Das Ergebnis der abschließenden Gesamtbeurteilung wird mit dem Patienten ausführlich besprochen und in einem Allergiepass niedergeleg
Allergologische Diagnostik von Überempfindlichkeitsreaktionen auf Arzneimittel
Drug hypersensitivity reactions have to be tested to identify the culprit substance. The history includes the general information and specific data concerning used drugs, the classification and circumstances of the reaction. Skin tests are performed in all hypersensitivity reactions with allergic symptoms. Tests should be done between four weeks and six months after clearance of the symptoms by performing skin prick test, intradermal test, patch test or photopatch test. Validated tests for the detection of specific IgE antibodies in the serum are available for only few drugs, especially betalactam antibiotics. Other laboratory tests, e.g., the basophil activation test are done only in special cases. Provocation tests are indicated, if the culprit drug cannot be identified by the above mentioned tests. If possible, the evaluation of provocation tests should rely on objective parameters. The concluding assessment will be discussed with the patient and will be documented in an allergy pass
Bures volume of the set of mixed quantum states
We compute the volume of the N^2-1 dimensional set M_N of density matrices of
size N with respect to the Bures measure and show that it is equal to that of a
N^2-1 dimensional hyper-halfsphere of radius 1/2. For N=2 we obtain the volume
of the Uhlmann 3-D hemisphere, embedded in R^4. We find also the area of the
boundary of the set M_N and obtain analogous results for the smaller set of all
real density matrices. An explicit formula for the Bures-Hall normalization
constants is derived for an arbitrary N.Comment: 15 revtex pages, 2 figures in .eps; ver. 3, Eq. (4.19) correcte
Mouse nuclear myosin I knock-out shows interchangeability and redundancy of myosin isoforms in the cell nucleus.
Nuclear myosin I (NM1) is a nuclear isoform of the well-known "cytoplasmic" Myosin 1c protein (Myo1c). Located on the 11(th) chromosome in mice, NM1 results from an alternative start of transcription of the Myo1c gene adding an extra 16 amino acids at the N-terminus. Previous studies revealed its roles in RNA Polymerase I and RNA Polymerase II transcription, chromatin remodeling, and chromosomal movements. Its nuclear localization signal is localized in the middle of the molecule and therefore directs both Myosin 1c isoforms to the nucleus. In order to trace specific functions of the NM1 isoform, we generated mice lacking the NM1 start codon without affecting the cytoplasmic Myo1c protein. Mutant mice were analyzed in a comprehensive phenotypic screen in cooperation with the German Mouse Clinic. Strikingly, no obvious phenotype related to previously described functions has been observed. However, we found minor changes in bone mineral density and the number and size of red blood cells in knock-out mice, which are most probably not related to previously described functions of NM1 in the nucleus. In Myo1c/NM1 depleted U2OS cells, the level of Pol I transcription was restored by overexpression of shRNA-resistant mouse Myo1c. Moreover, we found Myo1c interacting with Pol II. The ratio between Myo1c and NM1 proteins were similar in the nucleus and deletion of NM1 did not cause any compensatory overexpression of Myo1c protein. We observed that Myo1c can replace NM1 in its nuclear functions. Amount of both proteins is nearly equal and NM1 knock-out does not cause any compensatory overexpression of Myo1c. We therefore suggest that both isoforms can substitute each other in nuclear processes
Effective Immunological Guidance of Genetic Analyses Including Exome Sequencing in Patients Evaluated for Hemophagocytic Lymphohistiocytosis
We report our experience in using flow cytometry-based immunological screening prospectively as a decision tool for the use of genetic studies in the diagnostic approach to patients with hemophagocytic lymphohistiocytosis (HLH). We restricted genetic analysis largely to patients with abnormal immunological screening, but included whole exome sequencing (WES) for those with normal findings upon Sanger sequencing. Among 290 children with suspected HLH analyzed between 2010 and 2014 (including 17 affected, but asymptomatic siblings), 87/162 patients with "full" HLH and 79/111 patients with "incomplete/atypical" HLH had normal immunological screening results. In 10 patients, degranulation could not be tested. Among the 166 patients with normal screening, genetic analysis was not performed in 107 (all with uneventful follow-up), while 154 single gene tests by Sanger sequencing in the remaining 59 patients only identified a single atypical CHS patient. Flow cytometry correctly predicted all 29 patients with FHL-2, XLP1 or 2. Among 85 patients with defective NK degranulation (including 13 asymptomatic siblings), 70 were Sanger sequenced resulting in a genetic diagnosis in 55 (79%). Eight patients underwent WES, revealing mutations in two known and one unknown cytotoxicity genes and one metabolic disease. FHL3 was the most frequent genetic diagnosis. Immunological screening provided an excellent decision tool for the need and depth of genetic analysis of HLH patients and provided functionally relevant information for rapid patient classification, contributing to a significant reduction in the time from diagnosis to transplantation in recent years
A combined computational and functional approach identifies IGF2BP2 as a driver of chemoresistance in a wide array of pre-clinical models of colorectal cancer
Aim Chemoresistance is a major cause of treatment failure in colorectal cancer (CRC) therapy. In this study, the
impact of the IGF2BP family of RNA-binding proteins on CRC chemoresistance was investigated using in silico, in vitro,
and in vivo approaches.
Methods Gene expression data from a well-characterized cohort and publicly available cross-linking immunoprecipi‑
tation sequencing (CLIP-Seq) data were collected. Resistance to chemotherapeutics was assessed in patient-derived
xenografts (PDXs) and patient-derived organoids (PDOs). Functional studies were performed in 2D and 3D cell culture
models, including proliferation, spheroid growth, and mitochondrial respiration analyses.
Results We identifed IGF2BP2 as the most abundant IGF2BP in primary and metastastatic CRC, correlating with
tumor stage in patient samples and tumor growth in PDXs. IGF2BP2 expression in primary tumor tissue was signif‑
cantly associated with resistance to selumetinib, geftinib, and regorafenib in PDOs and to 5-fuorouracil and oxalipl‑
atin in PDX in vivo. IGF2BP2 knockout (KO) HCT116 cells were more susceptible to regorafenib in 2D and to oxaliplatin,
selumitinib, and nintedanib in 3D cell culture. Further, a bioinformatic analysis using CLIP data suggested stabiliza‑
tion of target transcripts in primary and metastatic tumors. Measurement of oxygen consumption rate (OCR) and
extracellular acidifcation rate (ECAR) revealed a decreased basal OCR and an increase in glycolytic ATP production
rate in IGF2BP2 KO. In addition, real-time reverse transcriptase polymerase chain reaction (qPCR) analysis confrmed
decreased expression of genes of the respiratory chain complex I, complex IV, and the outer mitochondrial membrane
in IGF2BP2 KO cells. Conclusions IGF2BP2 correlates with CRC tumor growth in vivo and promotes chemoresistance by altering mito‑
chondrial respiratory chain metabolism. As a druggable target, IGF2BP2 could be used in future CRC therapy to
overcome CRC chemoresistance
Ultrafast electronic read-out of diamond NV centers coupled to graphene
Nonradiative transfer processes are often regarded as loss channels for an
optical emitter1, since they are inherently difficult to be experimentally
accessed. Recently, it has been shown that emitters, such as fluorophores and
nitrogen vacancy centers in diamond, can exhibit a strong nonradiative energy
transfer to graphene. So far, the energy of the transferred electronic
excitations has been considered to be lost within the electron bath of the
graphene. Here, we demonstrate that the trans-ferred excitations can be
read-out by detecting corresponding currents with picosecond time resolution.
We electrically detect the spin of nitrogen vacancy centers in diamond
electronically and con-trol the nonradiative transfer to graphene by electron
spin resonance. Our results open the avenue for incorporating nitrogen vacancy
centers as spin qubits into ultrafast electronic circuits and for harvesting
non-radiative transfer processes electronically
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