Electronic structure of the molecule based magnet Cu PM(NO3)2 (H2O)2

We present density functional calculations on the molecule based S=1/2 antiferromagnetic chain compound Cu PM(NO3)2 (H2O)2; PM = pyrimidine. The properties of the ferro- and antiferromagnetic state are investigated at the level of the local density approximation and with the hybrid functional B3LYP. Spin density maps illustrate the exchange path via the pyrimidine molecule which mediates the magnetism in the one-dimensional chain. The computed exchange coupling is antiferromagnetic and in reasonable agreement with the experiment. It is suggested that the antiferromagnetic coupling is due to the possibility of stronger delocalization of the charges on the nitrogen atoms, compared to the ferromagnetic case. In addition, computed isotropic and anisotropic hyperfine interaction parameters are compared with recent NMR experiments

Linear analysis of the influence of FIR feedback filters on the response of the pulsed digital oscillator

The original publication is available at www.springerlink.comThe objective of this work is to extend the linear analysis of PulsedDigitalOscillators to those topologies having a Finite Impulse Response (FIR) in the feedback loop of the circuit. It will be shown with two specific examples how the overall response of the oscillator can be adjusted to some point by changing the feedback filter, when the resonator presents heavy damping losses. Extensive discrete-time simulations and experimental results obtained with a MEMS cantilever with thermoelectric actuation and piezoresistive position sensing are presented. It will be experimentally shown that the performance of the oscillator is good even below the Nyquist limit

Insight into the exoproteome of the tissue-derived trypomastigote form of <em>trypanosoma cruzi</em>

The protozoan parasite Trypanosoma cruzi causes Chagas disease, one of the major neglected infectious diseases. It has the potential to infect any nucleated mammalian cell. The secreted/excreted protein repertoire released by T. cruzi trypomastigotes is crucial in host-pathogen interactions. In this study, mammalian tissue culture-derived trypomastigotes (Y strain) were used to characterize the exoproteome of the infective bloodstream life form. Proteins released into the serum-free culture medium after 3h of incubation were harvested and digested with trypsin. NanoLC-MS/MS analysis resulted in the identification of 540 proteins, the largest set of released proteins identified to date in Trypanosome spp. Bioinformatic analysis predicted most identified proteins as secreted, predominantly by non-classical pathways, and involved in host-cell infection. Some proteins possess predicted GPI-anchor signals, these being mostly trans-sialidases, mucin associated surface proteins and surface glycoproteins. Moreover, we enriched phosphopeptides and glycopeptides from tryptic digests. The majority of identified glycoproteins are trans-sialidases and surface glycoproteins involved in host-parasite interaction. Conversely, most identified phosphoproteins have no Gene Ontology classification. The existence of various proteins related to similar functions in the exoproteome likely reflects this parasite’s enhanced mechanisms for adhesion, invasion and internalization of different host-cell types, and escape from immune defences

Artificial Neural Networks as Non-Linear Extensions of Statistical Methods in Astronomy

We attempt to de-mistify Artificial Neural Networks (ANNs) by considering special cases which are related to other statistical methods common in Astronomy and other fields. In particular we show how ANNs generalise Bayesian methods, multi-parameter fitting, Principal Component Analysis (PCA), Wiener filtering and regularisation methods. Examples of morphological classification of galaxies illustrate how non-linear ANNs improve on linear techniques.Comment: 9 pages, uu-encoded compressed postscript file. Also available by anonymous ftp to cast0.ast.cam.ac.uk (131.111.68.35) at ftp://cast0.ast.cam.ac.uk/pub/lahav/vistas/vistas4.ps.Z with figure at ftp://cast0.ast.cam.ac.uk/pub/lahav/vistas/fig1.ps.Z To appear in Vistas in Astronomy, special issue on Artificial Neural Networks in Astronom

Time delay of SBS 0909+532

The time delays between the components of a lensed quasar are basic tools to analyze the expansion of the Universe and the structure of the main lens galaxy halo. In this paper, we focus on the variability and time delay of the double system SBS 0909+532A,B as well as the time behaviour of the field stars. We use VR optical observations of SBS 0909+532A,B and the field stars in 2003. The frames were taken at Calar Alto, Maidanak and Wise observatories, and the VR light curves of the field stars and quasar components are derived from aperture and point-spread function fitting methods. We measure the R-band time delay of the system from the chi-square and dispersion techniques and 1000 synthetic light curves based on the observed records. One nearby field star (SBS 0909+532c) is found to be variable, and the other two nearby field stars are non-variable sources. With respect to the quasar components, the R-band records seem more reliable and are more densely populated than the V-band ones. The observed R-band fluctuations permit a pre-conditioned measurement of the time delay. From the chi-square minimization, if we assume that the quasar emission is observed first in B and afterwards in A (in agreement with basic observations of the system and the corresponding predictions), we obtain a delay of - 45 (+ 1)/(- 11) days (95% confidence interval). The dispersion technique leads to a similar delay range. A by-product of the analysis is the determination of a totally corrected flux ratio in the R band (corrected by the time delay and the contamination due to the galaxy light). Our 95% measurement of this ratio (0.575 +/- 0.014 mag) is in excellent agreement with previous results from contaminated fluxes at the same time of observation.Comment: 26 pages, 15 figures, Astronomy and Astrophysics (see also http://www.astro.ulg.ac.be/RPub/Colloques/JENAM/proceedings/proceedings.html - Quasars Section

Il Cristo in forma Pietatis del Rosso Fiorentino fra devozione e bellezza

<p>Differential distribution pattern of root- identified proteins in the four conditions described: TT, 42T, 42FS and 42RS.</p

Inoculation of cucumber, melón and zucchini varieties with Tomato leaf curl New Delhi virus (ToLCNDV) and evaluation of infection using different methods

This is the peer reviewed version of the following article: Figás-Moreno, MDR.; Alfaro Fernández, AO.; Font San Ambrosio, MI.; Borràs Palomares, D.; Casanova-Calancha, C.; Hurtado Ricart, M.; Plazas Ávila, MDLO.... (2017). Inoculation of cucumber, melón and zucchini varieties with Tomato leaf curl New Delhi virus (ToLCNDV) and evaluation of infection using different methods. Annals of Applied Biology. 170(3):405-414. doi:10.1111/aab.12344, which has been published in final form at http://doi.org/10.1111/aab.12344. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] The disease caused by Tomato leaf curl New Delhi virus (ToLCNDV), which is naturally transmitted by the whitefly Bemisia tabaci, causes important economic losses in cucurbit crops. The availability of simple and efficient inoculation protocols and detection methods is necessary for screening varieties and germplasm collections as well as for breeding populations. We evaluated the infectivity of ToLCNDV inocula prepared using three different buffers for mechanical sap inoculation in a susceptible variety of zucchini. We found that inoculum prepared with buffer III, which contains polyvinylpyrrolidone, is highly efficient for mechanical inoculation, with 100% of plants displaying severe symptoms 21 days post-inoculation. Using this buffer, we mechanically inoculated 19 commercial varieties of cucurbit crops (six of cucumber, six of melon and seven of zucchini), evaluated the evolution of symptoms and diagnosed infection using nine different ToLCNDV detection methods (four based on serology, four based on molecular hybridization and one based on PCR detection). The results revealed that all varieties are susceptible, although cucumber varieties display less severe symptoms than those of melon or zucchini. All detection methods were highly efficient (more than 85% of plants testing positive) in melon and zucchini, but in cucumber, the percentage of positive plants detected with serology and molecular hybridization methods ranged from 20.4% with Squash leaf curl virus (SLCV) antiserum, to 78.5% with DNA extract hybridization. Overall, the best detection results were obtained with PCR, with 92.6%, 92.4% and 98.4% cucumber, melon and zucchini plants, respectively, testing positive. When considering the overall results in the three crops, the best serology and molecular hybridization methods were those using Watermelon chlorotic stunt virus (WmCSV) antiserum and DNA extract, respectively. The inoculation methodology developed and the information on detection methods are of great relevance for the selection and breeding of varieties of cucurbit crops that are tolerant or resistant to ToLCNDV.Figás-Moreno, MDR.; Alfaro Fernández, AO.; Font San Ambrosio, MI.; Borràs Palomares, D.; Casanova-Calancha, C.; Hurtado Ricart, M.; Plazas Ávila, MDLO.... (2017). Inoculation of cucumber, melón and zucchini varieties with Tomato leaf curl New Delhi virus (ToLCNDV) and evaluation of infection using different methods. Annals of Applied Biology. 170(3):405-414. doi:10.1111/aab.12344S405414170

Acute Graft-vs.-Host Disease-Associated Endothelial Activation in vitro Is Prevented by Defibrotide

Altres ajuts: This study was supported in part by Jazz Pharmaceuticals Plc (IST-16-10355), German Jose Carreras Leukaemia Foundation (11R/2016 and 03R/2019).Angiogenesis and endothelial activation and dysfunction have been associated with acute graft-vs.-host disease (aGVHD), pointing to the endothelium as a potential target for pharmacological intervention. Defibrotide (DF) is a drug with an endothelium-protective effect that has been approved for the treatment of veno-occlusive disease/sinusoidal obstruction syndrome after allogeneic hematopoietic cell transplantation. Clinical data suggest that DF also reduces the incidence of aGVHD; however, the mechanisms of DF-mediated aGVHD regulation have not been examined. To investigate possible DF-mediated prophylactic and therapeutic mechanisms in aGVHD, we performed in vitro studies using endothelial cell (EC) lines. We found that DF significantly and dose-dependently suppressed EC proliferation and notably reduced their ability to form vascular tubes in Matrigel. To explore whether DF administered prophylactically or therapeutically has a significant effect on aGVHD endothelial dysfunction, ECs were exposed to media containing sera from patients with aGVHD (n = 22) in the absence or presence of DF and from patients that did not develop aGVHD (n = 13). ECs upregulated adhesion molecules (vascular cell adhesion molecule 1, intercellular adhesion molecule 1), the adherence junction protein VE-cadherin, von Willebrand factor (VWF), and Akt phosphorylation in response to aGVHD sera. These responses were suppressed upon treatment with DF. In summary, DF inhibits vascular angiogenesis and endothelial activation induced by sera from aGVHD patients. Our results support the view that DF has notable positive effects on endothelial biology during aGVHD

Discovery and physical characterization as the first response to a potential asteroid collision: The case of 2023 DZ2

Near-Earth asteroids (NEAs) that may evolve into impactors deserve detailed threat assessment studies. Early physical characterization of a would-be impactor may help in optimizing impact mitigation plans. We first detected NEA 2023~DZ$_{2}$ on 27--February--2023. After that, it was found to have a Minimum Orbit Intersection Distance (MOID) with Earth of 0.00005~au as well as an unusually high initial probability of becoming a near-term (in 2026) impactor. We aim to perform a rapid but consistent dynamical and physical characterization of 2023~DZ$_{2}$ as an example of a key response to mitigate the consequences of a potential impact. We use a multi-pronged approach, drawing from various methods (observational/computational) and techniques (spectroscopy/photometry from multiple instruments), and bringing the data together to perform a rapid and robust threat assessment.} The visible reflectance spectrum of 2023~DZ$_{2}$ is consistent with that of an X-type asteroid. Light curves of this object obtained on two different nights give a rotation period $P$=6.2743$\pm$0.0005 min with an amplitude $A$=0.57$\pm$0.14~mag. We confirm that although its MOID is among the smallest known, 2023~DZ$_{2}$ will not impact Earth in the foreseeable future as a result of secular near-resonant behaviour. Our investigation shows that coordinated observation and interpretation of disparate data provides a robust approach from discovery to threat assessment when a virtual impactor is identified. We prove that critical information can be obtained within a few days after the announcement of the potential impactor.Comment: Accepted for publication in Astronomy and Astrophysics, 15 page