Properties of Matrix Orthogonal Polynomials via their Riemann-Hilbert Characterization

We give a Riemann-Hilbert approach to the theory of matrix orthogonal polynomials. We will focus on the algebraic aspects of the problem, obtaining difference and differential relations satisfied by the corresponding orthogonal polynomials. We will show that in the matrix case there is some extra freedom that allows us to obtain a family of ladder operators, some of them of 0-th order, something that is not possible in the scalar case. The combination of the ladder operators will lead to a family of second-order differential equations satisfied by the orthogonal polynomials, some of them of 0-th and first order, something also impossible in the scalar setting. This shows that the differential properties in the matrix case are much more complicated than in the scalar situation. We will study several examples given in the last years as well as others not considered so far

Flavour and polarisation in heavy neutrino production at e+ e- colliders

We analyse l W nu production at ILC, paying special attention to the role of the final lepton flavour and beam polarisation in the search for a new heavy neutrino N. We show that a sizeable coupling to the electron V_eN ~ 10^-2 is necessary to have an observable signal in any of the channels, despite the fact that the signal may be more visible in muon or tau final states. The non-observation of a heavy neutrino at ILC will improve the present upper bound on its mixing with the electron by more than one order of magnitude, V_eN < 0.007 for m_N between 200 and 400 GeV.Comment: 17 pages, 5 PS figures. References added. To be published in PL

Tuning the size and composition of manganese oxide nanoparticles through varying temperature ramp and aging time

Manganese oxide (MnO) nanoparticles (NPs) can serve as robust pH-sensitive contrast agents for magnetic resonance imaging (MRI) due to Mn2+ release at low pH, which generates a ~30 fold change in T1 relaxivity. Strategies to control NP size, composition, and Mn2+ dissolution rates are essential to improve diagnostic performance of pH-responsive MnO NPs. We are the first to demonstrate that MnO NP size and composition can be tuned by the temperature ramping rate and aging time used during thermal decomposition of manganese(II) acetylacetonate. Two different temperature ramping rates (10°C/min and 20°C/min) were applied to reach 300°C and NPs were aged at that temperature for 5, 15, or 30 min. A faster ramping rate and shorter aging time produced the smallest NPs of ~23 nm. Shorter aging times created a mixture of MnO and Mn3O4 NPs, whereas longer aging times formed MnO. Our results indicate that a 20°C/min ramp rate with an aging time of 30 min was the ideal temperature condition to form the smallest pure MnO NPs of ~32 nm. However, Mn2+ dissolution rates at low pH were unaffected by synthesis conditions. Although Mn2+ production was high at pH 5 mimicking endosomes inside cells, minimal Mn2+ was released at pH 6.5 and 7.4, which mimic the tumor extracellular space and blood, respectively. To further elucidate the effects of NP composition and size on Mn2+ release and MRI contrast, the ideal MnO NP formulation (~32 nm) was compared with smaller MnO and Mn3O4 NPs. Small MnO NPs produced the highest amount of Mn2+ at acidic pH with maximum T1 MRI signal; Mn3O4 NPs generated the lowest MRI signal. MnO NPs encapsulated within poly(lactide-co-glycolide) (PLGA) retained significantly higher Mn2+ release and MRI signal compared to PLGA Mn3O4 NPs. Therefore, MnO instead of Mn3O4 should be targeted intracellularly to maximize MRI contrast

Linear polarization Yb³⁺-doped fiber laser with novel innerclad structures

Results on high radiance Yb3+-doped fiber lasers with novel double innerclad structures (double-D clad and four hole) and polarized output at ≈1090 nm are presented. We have demonstrated >40% of the total output power being polarized, making the fiber laser suitable for LIDAR and second-harmonic generation (SHG) applications. It also showed a 10-nm tuning range with low (less than 10 mW) average power variations. The narrow linewidth source was pumped with a low cost, low brightness laser diode, and exhibited a relatively low slope efficiency, which gives room for improvement by using a 976-nm pump source where Yb3+ has a narrower linewidth and at least five times higher absorption

Raman threshold for nth-order cascade Raman amplification

We study theoretically and experimentally Raman threshold for 1, 2, ... , n orders Stokes in a free running configuration. Using alternative way to solve the differential coupled equations that describe the stimulate Raman scattering, we find simple mathematical expressions that allow calculating the necessary pumping power to obtain Raman threshold for nth-order Stokes and the maximum output power available in each Stokes. The theoretical calculations coincide with the results obtained experimentally

SAVASA project @ TRECVID 2012: interactive surveillance event detection

In this paper we describe our participation in the interactive surveillance event detection task at TRECVid 2012. The system we developed was comprised of individual classifiers brought together behind a simple video search interface that enabled users to select relevant segments based on down~sampled animated gifs. Two types of user -- `experts' and `end users' -- performed the evaluations. Due to time constraints we focussed on three events -- ObjectPut, PersonRuns and Pointing -- and two of the five available cameras (1 and 3). Results from the interactive runs as well as discussion of the performance of the underlying retrospective classifiers are presented

PH-Sensitive self-assembling nanoparticles for tumor near-infrared fluorescence imaging and chemo-photodynamic combination therapy

The development of visual tumor theranostic nanoparticles has become a great challenge. In this study, d-a-tocopheryl polyethylene glycol 1000 succinate (TPGS) was conjugated to acid-sensitive cis-aconitic anhydride-modified doxorubicin (CAD) to obtain pH-sensitive anti-tumor prodrug nanoparticles (TCAD NPs) via self-assembling. Subsequently, the photosensitizer chlorin e6 (Ce6) was loaded into the resulting prodrug nanoparticles to prepare a novel tumor near-infrared fluorescence imaging and chemo-photodynamic combination therapy system (TCAD@Ce6 NPs). An accelerated release of doxorubicin (DOX) and chlorin e6 (Ce6) from the TCAD@Ce6 NPs could be achieved due to the hydrolysis of the acid-sensitive amide linker under mild acidic conditions (pH = 5.5). An in vitro experiment showed that A549 lung cancer cells exhibited a significantly higher uptake of DOX and Ce6 by using our delivery system than the free form of DOX and Ce6. An in vivo experiment showed that TCAD@Ce6 NPs displayed better tumor targeting gathering through the enhanced permeability and retention (EPR) effect than free Ce6, thus improving fluorescence imaging. Moreover, the chemo-photodynamic combination therapy of TCAD@Ce6 NPs combined with near-infrared laser irradiation was confirmed to be capable of inducing high apoptosis and necrosis of tumor cells (A549) in vitro and to display a significantly higher tumor growth suppression in the A549 lung cancer-bearing mice model. Furthermore, compared with exclusive chemotreatment (DOX) or photodynamic treatment (Ce6), our system showed enhanced therapeutic effects both in vitro and in vivo. In conclusion, the high performance TCAD@Ce6 NPs can be used as a promising NIR fluorescence imaging and highly effective chemo-photodynamic system for theranostics of lung cancer, etc. in the near future

Molecular and biological characterization of an isolate of Tomato mottle mosaic virus (ToMMV) infecting tomato and other experimental hosts in eastern Spain

[EN] Tomato is known to be a natural and experimental reservoir host for many plant viruses. In the last few years a new tobamovirus species, Tomato mottle mosaic virus (ToMMV), has been described infecting tomato and pepper plants in several countries worldwide. Upon observation of symptoms in tomato plants growing in a greenhouse in Valencia, Spain, we aimed to ascertain the etiology of the disease. Using standard molecular techniques, we first detected a positive sense single-stranded RNA virus as the probable causal agent. Next, we amplified and sequenced its full-length genomic RNA which identified the virus as a new ToMMV isolate. Through extensive assays on distinct plant species, we investigated the host range of the Spanish ToMMV isolate. Several plant species were locally and/or systemically infected by the virus, some of which had not been previously reported as ToMMV hosts despite they are commonly used in research greenhouses. Finally, two reliable molecular diagnostic techniques were developed and used to assess the presence of ToMMV. This is the first observation of ToMMV in tomato plants in Europe. We discuss the possibility that, given the high sequence homology between ToMMV and Tomato mosaic virus, the former may have been mistakenly diagnosed as the latter by serological methods.This work was supported by grants BFU2015-70261-P and BFU2015-65037-P (to C.H. and S.F.E., respectively) from Spain Ministry of Economy, Industry and Competitiveness/FEDER.Ambros Palaguerri, S.; Martinez, F.; Ivars, P.; Hernandez Fort, C.; De La Iglesia Jordán, F.; Elena Fito, SF. (2017). Molecular and biological characterization of an isolate of Tomato mottle mosaic virus (ToMMV) infecting tomato and other experimental hosts in eastern Spain. European Journal of Plant Pathology. 149(2):261-268. https://doi.org/10.1007/s10658-017-1180-2S2612681492Fillmer, K., Adkins, S., Pongam, P., & D’Ella, T. (2015). Complete genome sequence of a Tomato mottle mosaic virus isolated from the United States. Genome Announcements, 3(2), e00167–e00115.Hadas, R., Pearlsman, M., Gefen, T., Lachman, O., Hadar, E., Sharabany, G., et al. (2004). Indexing system for Tomato mosaic virus (ToMV) in commercial tomato seed lots. Phytoparasitica, 32(4), 421–424.Lewandowski, D. J., & Dawson, W. O. (1998). Tobamoviruses. In A. Granoff & R. G. Webster (Eds.), Encyclopedia of virology (Vol. 3, 2nd ed., pp. 1780–1783). New York: Academic Press Inc..Li, R., Gao, S., Fel, Z., & Ling, K. (2013). Complete genome sequence of a new Tobamovirus naturally infecting tomatoes in Mexico. Genome Announcements, 1(5), e00794–e00713.Li, Y. Y., Wang, C. L., Xiang, D., Li, R. H., Liu, Y., & Li, F. (2014). First report of Tomato mottle mosaic virus infection of pepper in China. Plant Disease, 98(10), 1447.Martin, D. P., Murrell, B., Golden, M., Khoosal, A., Muhire, B. (2015). RDP4: detection and analysis of recombination patterns in virus genomes. Virus Evolution, 1(1), vev003.Moreira, S. R., Eiras, M., Chaves, A. L. R., Galleti, S. R., & Colariccio, A. (2003). Characterição de uma nova estirpe do Tomato mosaic virus isolada de tomateiro no estado de São Paulo. Fitopatologia Brasileira, 28(6), 602–607.Padmanabhan, C., Zheng, Y., Li, R., Martin, G. B., Fei, Z., & Ling, K. S. (2015). Complete genome sequence of a tomato-infecting Tomato mottle mosaic virus in New York. Genome Announcements, 3(6), e01523–e01515.Pirovano, W., Boetzer, M., Miozzi, L., & Pantaleo, V. (2015). Bioinformatics approaches for viral metagenomics in plants using short RNAs: Model case of study and application to a Cicer arietinum population. Frontiers in Microbiology, 5, 790.Ruiz-Ruiz, S., Moreno, P., Guerri, J., & Ambrós, S. (2006). The complete nucleotide sequence of a severe stem pitting isolate of Citrus tristeza virus from Spain: Comparison with isolates from different origins. Archives of Virology, 151(2), 387398.Salem, N., Mansour, A., Ciuffo, M., Falk, B. W., & Turina, M. (2016). A new tobamovirus infecting tomato crops in Jordan. Archives of Virology, 161(2), 503–506.Soler, S., Prohens, J., López, C., Aramburu, J., Galipienso, L., & Nuez, F. (2010). Viruses infecting tomato in València, Spain: Occurrence, distribution and effect of seed origin. Journal of Phytopathology, 158(11–12), 797–805.Tamura, L., Stecher, G., Peterson, D., Filipski, A., & Kumar, S. (2013). MEGA6: Molecular evolutionary genetics analysis version 6.0. Molecular Biology and Evolution, 30(12), 2725–2729.Turina, M., Geraats, B. P. J., & Ciuffo, M. (2016). First report of Tomato mottle mosaic virus in tomato crops in Israel. New Disease Reports, 33, 1.Webster, C. G., Rosskopf, E. N., Lucas, L., Mellinger, H. C., & Adkins, S. (2014). First report of Tomato mottle mosaic virus infecting tomato in the United States. Plant Health Progress. doi: 10.1094/PHP-BR-14-0023

Defects of splicing in antithrombin deficiency

Background: There is increasing evidence supporting the relevance of aberrant splicing in multiple disorders. In antithrombin deficiency only 22 intronic mutations affecting splicing sites (7% of SERPINC1 mutations) are considered as splicing mutations. Methods: SERPINC1 was analyzed by Sanger sequencing and MLPA in 141 unrelated cases with antithrombin deficiency. Plasma antithrombin was studied by functional and western blot assays, purified by FPLC and characterized by proteomic analysis. In silico predictions on splicing was done with the Human Splicing Finder software. Results: We detected 89 different SERPINC1 defects, 13 with potential effect on splicing. Ten cases presented 9 mutations disturbing splicing sites, 5 new. Three gross or small gene defects also disturbed a correct splicing. Interestingly, the first duplication of a single exon ever described (c.1154-13_1218+115dup), caused mild deficiency (75%). A deeper intronic mutation (c.1154-14G>A), identified in three unrelated patients with traces of disulphide dimers of antithrombin in plasma, created a cryptic splicing site that might generate a variant with 4 additional in frame residues according to in silico predictions. This aberrant splicing was confirmed by proteomic analysis of the dimer purified from plasma. Conclusions: A high proportion of cases with antithrombin deficiency (up to 13%) may be explained by an aberrant splicing. Up to 15% of mutations in SERPINC1: splicing site variations, gross gene defects and deep intronic mutations, may affect a correct splicing with three potential consequences type I, type II, and even moderate antithrombin deficiency

Potential Energy Landscape Equation of State

Depth, number, and shape of the basins of the potential energy landscape are the key ingredients of the inherent structure thermodynamic formalism introduced by Stillinger and Weber [F. H. Stillinger and T. A. Weber, Phys. Rev. A 25, 978 (1982)]. Within this formalism, an equation of state based only on the volume dependence of these landscape properties is derived. Vibrational and configurational contributions to pressure are sorted out in a transparent way. Predictions are successfully compared with data from extensive molecular dynamics simulations of a simple model for the fragile liquid orthoterphenyl.Comment: RevTeX4, 4 pages, 5 figure