1,732 research outputs found
Calculable inverse-seesaw neutrino masses in supersymmetry
We provide a scenario where naturally small and calculable neutrino masses
arise from a supersymmetry breaking renormalization-group-induced vacuum
expectation value. We adopt a minimal supergravity scenario without ad hoc
supersymmetric mass parameters. The lightest supersymmetric particle can be an
isosinglet scalar neutrino state, potentially viable as WIMP dark matter
through its Higgs new boson coupling. The scenario leads to a plethora of new
phenomenological implications at accelerators including the Large Hadron
Collider.Comment: LaTeX, 5 pages, 4 figures. Comments and references added. Final
version to appear in PR
Willingness to pay for biofertilizers among grain legume farmers in northern Ghana
Open Access Journal; Published online: 27 April 2018Background: The call for use of improved Soil Fertility Management (SFM) technologies is a prerequisite to increase agricultural productivity among farmers. This study assessed farmers’ willingness to pay (WTP) for selected financially rewarding biofertilizer technologies/packages for legume production in northern Ghana. Primary data was elicited from 400 grain legume farmers
selected from Northern and Upper West Regions of Ghana through a simple random sampling technique. The double bounded dichotomous choice (DBDC) format of contingent valuation approach was employed to elicit willingness to pay values and determinants of farmers WTP was evaluated using the maximum likelihood estimation procedure.
Results: The results showed that about 60%, 25% and 46% of soya, cowpea and groundnuts farmers were willing to pay for the selected biofertilizers (Biofix, BR3267 and Legumefix respectively) at prices not exceeding GHC 14.00, GHC 28.00 and GHC 20.00 per 0.2kg of the respective biofertilizers. Legume farmers in Northern Region were however willing to pay higher for the three biofertilizer technologies as compared to their counterparts in Upper West Region. For 0.2 kg each of Biofix, BR3267 and Legumefix, farmers in Northern Region were willing to pay approximately GHC 17.00, GHC 12.00 and GHC 23.00 respectively whereas those in Upper West Region were willing to pay GHC 14.00, GHC 9.00 and GHC 11.00 for the same quantity of each
biofertilizer. The study identified farming experience, FBO membership, awareness and previous use of biofertilizers as significant determinants of farmers’ willingness to pay for Biofertilizers.
Conclusion: Comparatively, mean prices farmers are willing to pay for these three technologies are below ex-factory prices, hence subsidizing the cost of production of these biofertilizers in the initial stages would be relevant for improving farmers’ uptake of these fertilizers. Sustained awareness creation through periodic education and sensitization by using FBOs as leverage points
is also highly recommended to improve farmers’ understanding of the concept of biofertilizer use
Dengue Virus Inhibits Immune Responses in Aedes aegypti Cells
The ability of many viruses to manipulate the host antiviral immune response often results in complex host-pathogen interactions. In order to study the interaction of dengue virus (DENV) with the Aedes aegypti immune response, we have characterized the DENV infection-responsive transcriptome of the immune-competent A. aegypti cell line Aag2. As in mosquitoes, DENV infection transcriptionally activated the cell line Toll pathway and a variety of cellular physiological systems. Most notably, however, DENV infection down-regulated the expression levels of numerous immune signaling molecules and antimicrobial peptides (AMPs). Functional assays showed that transcriptional induction of AMPs from the Toll and IMD pathways in response to bacterial challenge is impaired in DENV-infected cells. In addition, Escherichia coli, a Gram-negative bacteria species, grew better when co-cultured with DENV-infected cells than with uninfected cells, suggesting a decreased production of AMPs from the IMD pathway in virus-infected cells. Pre-stimulation of the cell line with Gram-positive bacteria prior to DENV infection had no effect on DENV titers, while pre-stimulation with Gram-negative bacteria resulted in an increase in DENV titers. These results indicate that DENV is capable of actively suppressing immune responses in the cells it infects, a phenomenon that may have important consequences for virus transmission and insect physiology
Current and novel therapeutic opportunities for systemic therapy in biliary cancer
none24Biliary tract cancers (BTCs) are a group of rare and aggressive malignancies that arise in the biliary tree within and outside the liver. Beyond surgical resection, which is beneficial for only a small proportion of patients, current strategies for treating patients with BTCs include chemotherapy, as a single agent or combination regimens, in the adjuvant and palliative setting. Increased characterisation of the molecular landscape of these tumours has facilitated the identification of molecular vulnerabilities, such as IDH mutations and FGFR fusions, that can be exploited for the treatment of BTC patients. Beyond targeted therapies, active research avenues explore the development of novel therapeutics that target the crosstalk between cancer and stroma, the cellular pathways involved in the regulation of cell death, the chemoresistance phenotype and the dysregulation of RNA. In this review, we discuss the therapeutic opportunities currently available in the management of BTC patients, and explore the strategies that can support the implementation of precision oncology in BTCs, including novel molecular targets, liquid biopsies and patient-derived predictive tools.openMarin J.J.G.; Prete M.G.; Lamarca A.; Tavolari S.; Landa-Magdalena A.; Brandi G.; Segatto O.; Vogel A.; Macias R.I.R.; Rodrigues P.M.; Casta A.L.; Mertens J.; Rodrigues C.M.P.; Fernandez-Barrena M.G.; Da Silva Ruivo A.; Marzioni M.; Mentrasti G.; Acedo P.; Munoz-Garrido P.; Cardinale V.; Banales J.M.; Valle J.W.; Bridgewater J.; Braconi C.Marin, J. J. G.; Prete, M. G.; Lamarca, A.; Tavolari, S.; Landa-Magdalena, A.; Brandi, G.; Segatto, O.; Vogel, A.; Macias, R. I. R.; Rodrigues, P. M.; Casta, A. L.; Mertens, J.; Rodrigues, C. M. P.; Fernandez-Barrena, M. G.; Da Silva Ruivo, A.; Marzioni, M.; Mentrasti, G.; Acedo, P.; Munoz-Garrido, P.; Cardinale, V.; Banales, J. M.; Valle, J. W.; Bridgewater, J.; Braconi, C
The 2005 outburst of the halo black hole X-ray transient XTE J1118+480
We present optical and infrared monitoring of the 2005 outburst of the halo black hole X-ray transient XTE J1118+480. We measured a total outburst amplitude of ~5.7 ± 0.1 mag in the R band and ~5 mag in the infrared J, H, and Ks bands. The hardness ratio HR2 (5-12 keV : 3-5 keV) from the RXTE ASM data is 1.53 ± 0.02 at the peak of the outburst, indicating a hard spectrum. Both the shape of the light curve and the ratio LX(1-10 keV)/Lopt resemble the minioutbursts observed in GRO J0422+32 and XTE J1859+226. During early decline, we find a 0.02 mag amplitude variation consistent with a superhump modulation, like the one observed during the 2000 outburst. Similarly, XTE J1118+480 displayed a double-humped ellipsoidal modulation distorted by a superhump wave when settled into a near-quiescence level, suggesting that the disk expanded to the 3 : 1 resonance radius after outburst, where it remained until early quiescence. The system reached quiescence at R = 19.02 ± 0.03, about 3 months after the onset of the outburst. The optical rise preceded the X-ray rise by at most 4 days. The spectral energy distributions (SEDs) at the different epochs during outburst are all quasi-power laws with Fν να increasing toward the blue. At the peak of the outburst, we derived α = 0.49 ± 0.04 for the optical data alone and α = 0.1 ± 0.1 when fitting solely the infrared. This difference between the optical and the infrared SEDs suggests that the infrared is dominated by a different component (a jet?), whereas the optical is presumably showing the disk evolution
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV
We report the first measurement of charged particle elliptic flow in Pb-Pb
collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron
Collider. The measurement is performed in the central pseudorapidity region
(||<0.8) and transverse momentum range 0.2< < 5.0 GeV/. The
elliptic flow signal v, measured using the 4-particle correlation method,
averaged over transverse momentum and pseudorapidity is 0.087 0.002
(stat) 0.004 (syst) in the 40-50% centrality class. The differential
elliptic flow v reaches a maximum of 0.2 near = 3
GeV/. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow
increases by about 30%. Some hydrodynamic model predictions which include
viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/389
High proportion of cactus species threatened with extinction
This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.Consejo Nacional de Ciencia y Tecnologí
Mapping Protein Interactions between Dengue Virus and Its Human and Insect Hosts
Dengue virus (DENV) represents a major disease burden in tropical and subtropical regions of the world, and has shown an increase in the number of cases in recent years. DENV is transmitted to humans through the bite of an infected mosquito, typically Aedes aegypti, after which it begins the infection and replication lifecycle within human cells. To perform the molecular functions required for invasion, replication, and spread of the virus, proteins encoded by DENV must interact with and alter the behavior of protein networks in both of these hosts. In this work, we used a computational method based on protein structures to predict interactions between DENV and its human and insect hosts. We predict numerous interactions, with many involved in known cell death, stress, and immune system pathways. Further investigation of these predicted protein-protein interactions should provide targets to combat the clinical manifestations of this disease in humans as well as points of intervention focused within the mosquito vector
Nuclear expression of Rac1 in cervical premalignant lesions and cervical cancer cells
<p>Abstract</p> <p>Background</p> <p>Abnormal expression of Rho-GTPases has been reported in several human cancers. However, the expression of these proteins in cervical cancer has been poorly investigated. In this study we analyzed the expression of the GTPases Rac1, RhoA, Cdc42, and the Rho-GEFs, Tiam1 and beta-Pix, in cervical pre-malignant lesions and cervical cancer cell lines.</p> <p>Methods</p> <p>Protein expression was analyzed by immunochemistry on 102 cervical paraffin-embedded biopsies: 20 without Squamous Intraepithelial Lesions (SIL), 51 Low- grade SIL, and 31 High-grade SIL; and in cervical cancer cell lines C33A and SiHa, and non-tumorigenic HaCat cells. Nuclear localization of Rac1 in HaCat, C33A and SiHa cells was assessed by cellular fractionation and Western blotting, in the presence or not of a chemical Rac1 inhibitor (NSC23766).</p> <p>Results</p> <p>Immunoreacivity for Rac1, RhoA, Tiam1 and beta-Pix was stronger in L-SIL and H-SIL, compared to samples without SIL, and it was significantly associated with the histological diagnosis. Nuclear expression of Rac1 was observed in 52.9% L-SIL and 48.4% H-SIL, but not in samples without SIL. Rac1 was found in the nucleus of C33A and SiHa cells but not in HaCat cells. Chemical inhibition of Rac1 resulted in reduced cell proliferation in HaCat, C33A and SiHa cells.</p> <p>Conclusion</p> <p>Rac1 is expressed in the nucleus of epithelial cells in SILs and cervical cancer cell lines, and chemical inhibition of Rac1 reduces cellular proliferation. Further studies are needed to better understand the role of Rho-GTPases in cervical cancer progression.</p
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