181 research outputs found

    Numerical analysis of a family of simultaneous distributed-boundary mixed elliptic optimal control problems and their asymptotic behaviour through a commutative diagram and error estimates

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    In this paper, we consider a family of simultaneous distributed-boundary optimal control problems (PαP_{\alpha}) on the internal energy and the heat flux for a system governed by a mixed elliptic variational equality with a parameter α>0\alpha >0 and a simultaneous distributed-boundary optimal control problem (PP) governed also by an elliptic variational equality with a Dirichlet boundary condition on the same portion of the boundary. We formulate discrete approximations (Phα)\left(P_{h \alpha}\right) and (Ph)\left(P_h\right) of the problems (Pα)\left(P_\alpha\right) and (P)(P) respectively, for each h>0h>0 and for each α>0\alpha>0, through the finite element method with Lagrange's triangles of type 1 with parameter hh (the longest side of the triangles). The goal of this paper is to study the convergence of this family of discrete simultaneous distributed-boundary mixed elliptic optimal control problems (Phα)\left(P_{h \alpha}\right) when the parameters α\alpha goes to infinity and the parameter hh goes to zero simultaneously. We prove the convergence of the problems (Phα)\left(P_{h \alpha}\right) to the problem (Ph)\left(P_h\right) when α→+∞\alpha \rightarrow +\infty, for each h>0h>0. We study the convergence of the problems (Phα)\left(P_{h \alpha}\right) and (Ph)\left(P_h\right), for each α>0\alpha >0, when h→0+h \rightarrow 0^+ obtaining a commutative diagram which relates the continuous and discrete optimal control problems (Phα),(Pα),(Ph)\left(P_{h \alpha}\right),\left(P_\alpha\right),\left(P_h\right) and (P)(P) by taking the limits h→0+h \rightarrow 0^+ and α→+∞\alpha \rightarrow +\infty respectively. We also study the double convergence of (Phα)\left(P_{h \alpha}\right) to (P)(P) when (h,α)→(0+,+∞)(h, \alpha) \rightarrow(0^+,+\infty) which represents the diagonal convergence in the above commutative diagram.Comment: This paper has been published online in Nonlinear Analysis: Real World Applications. arXiv admin note: text overlap with arXiv:1512.0383

    Comparative clinico-pathological observations in young Zebu (Bos indicus) cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse infested areas of Northwest Ethiopia

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    BACKGROUND: The Northwest region of Ethiopia is affected by both tsetse and non-tsetse transmitted trypanosomosis with a huge impact on livestock productivity. The objective of this experimental study was to determine clinical and pathological findings in young Zebu cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse infested areas of Northwest Ethiopia. A total of 18 cattle (Bos indicus) aged between 6 and 12 months, purchased from a trypanosome-free and confirmed to be trypanosome negative divided into three groups of six animals were used. Animals in the first two groups (Group TT: tsetse infested isolate infected and Group NT: non-tsetse infested isolate infected) received 2 mL of infected blood from donor animals at 10(6) trypanosomes/mL, and the remaining group was non-infected control (NIC). Each group was observed for a period of eight consecutive weeks, daily for clinical signs and once per week for parasitaemia. Postmortem examinations were done on euthanized animals, and tissue samples were taken for histopathological analysis. RESULTS: The prepatent period of the disease was earlier in the NT group 6 days post infection (dpi) than TT group 12 dpi. The infection was characterized by reduced feed intake, intermittent pyrexia and parasitaemia, enlarged lymph nodes, lacrimation, reduced feed intake and emaciation. Less frequently diarrhea, oedema and nervous signs were observed in both groups of infected animals. At necropsy, infected animals showed enlarged spleen, enlarged lymph nodes, pneumonic and emphysematous lung, enlarged liver, and haemorrhages on the brain and intestine. Histopathological analysis revealed lymphoid hyperplasia of the spleen, necrosis of the liver, encephalitis and hyperplasia of lymph nodes. CONCLUSION: Trpanosoma vivax isolates from both tsetse infested and non-tsetse areas showed a variety of virulence factors leading to the development of acute clinical signs, gross and histopathological lesions. However, the parasitaemia and clinical signs appeared earlier in the NT compared to TT infected groups

    Longitudinal Evaluation of Serum MOG-IgG and AQP4-IgG Antibodies in NMOSD by a Semiquantitative Ratiometric Method

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    Background and purpose: Immunoadsorption (IA) is an antibody-depleting therapy used to treat neuromyelitis optica spectrum disorder (NMOSD) associated to antiaquaporin 4 (anti-AQP4-IgG) and antimyelin oligodendrocyte glycoprotein (anti-MOG-IgG) serum autoantibodies. Our aim was to evaluate longitudinal changes of serum MOG-IgG and AQP4-IgG antibody titer and to correlate it with the clinical status. Methods: Autoantibody titer and clinical features of two MOG-IgG+/AQP4-IgG– and two AQP4-IgG+/MOG-IgG– patients with NMOSD were collected at baseline (T0), after 6 IA courses (T1), and then 2 weeks (T2) and 6 months after treatment (T3). A fluorescent ratiometric assay was used for a quantitative detection of MOG and AQP4 antibodies, based on HEK-293 cells transfected with the full-length hMOG fused to GFP or h-AQP4-M23 isoform fused to m-cherry, respectively. We defined the antibody titer as MOG quantitative ratio (MOGqr) and AQP4 quantitative ratio (AQP4qr). Results: In Case 1, the MOGqr dropped from 0.98 at T0 to 0.14 at T3, and in Case 2, it decreased from 0.96 at T0 to undetectable at T3. In Case3, the AQP4qr remained high: 0.90 at T0 and 0.92 at T3. In Case 4, the AQP4qr decreased from 0.50 at T0 to undetectable at T3. Complete recovery was found in Cases 1, 2, and 4. Conclusions: Semiquantitative ratiometric method accurately detects even slight variation of MOG-IgG and AQP4-IgG titer, suggesting it may be useful to monitor the antibody titer during the disease course and maintenance immunotherapy

    Characterization of the ablation zones produced by three commercially available systems from a single vendor for radiofrequency thermoablation in an ex vivo swine liver model

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    Background: Radiofrequency Ablation (RFA) is rarely performed in veterinary medicine. A rationale exists for its use in selected cases of canine liver tumours. RFA induces ablation zones of variable size and geometry depending on the technique used and on the impedance of the targeted organ. Objectives: (a) to describe the geometry and reproducibility of the ablation zones produced by three commercially available systems from a single company, using isolated swine liver parenchyma as a model for future veterinary applications in vivo; (b) to study the effects of local saline perfusion into the ablated parenchyma through the electrode tip and of single versus double passage of the electrode on size, geometry and reproducibility of the ablation zones produced. Methods: Size, and geometry of ablation zones reproduced in six livers with one cooled and perfused (saline) and two cooled and non-perfused systems, after single or double passage (n = 6/condition), were assessed macroscopically on digitalized images by a blinded operator. Longitudinal and transverse diameters, equivalent diameter, estimated volume and roundness index were measured. Reproducibility was assessed as coefficient of variation. Results and Conclusions: Ablation zone reproducibility was higher when expressed in terms of ablation zone diameters than estimated volume. Local saline perfusion of the parenchyma through the electrode tip during RFA increased the ablation zone longitudinal diameter. Ablation zone estimated volume increased with saline perfusion only when double passage was performed. These data may provide useful information for those clinicians who intend to include RFA as an additive tool in veterinary interventional radiology

    MHC class I-related antigen-processing machinery component defects in feline mammary carcinoma.

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    Defects in HLA class I antigen-processing machinery (APM) component expression and/or function are frequent in human tumors. These defects may provide tumor cells with a mechanism to escape from recognition and destruction by HLA class I antigen-restricted, tumor antigen-specific cytotoxic T cells. However, expression and functional properties of MHC class I antigens and APM components in malignant cells in other animal species have been investigated to a limited extent. However, this information can contribute to our understanding of the mechanisms underlying the association of MHC class I antigen and APM component defects with malignant transformation of cells and to identify animal models to validate targeted therapies to correct these defects. To overcome this limitation in the present study, we have investigated the expression of the catalytic subunits of proteasome (Y, X, and Z) and of immunoproteasome (LMP2, LMP7, and LMP10) as well as of MHC class I heavy chain (HC) in 25 primary feline mammary carcinomas (FMCs) and in 23 matched healthy mammary tissues. We found a reduced expression of MHC class I HC and of LMP2 and LMP7 in tumors compared with normal tissues. Concordantly, proteasomal cleavage specificities in extracts from FMCs were different from those in healthy tissues. In addition, correlation analysis showed that LMP2 and LMP7 were concordantly expressed in FMCs, and their expression was significantly correlated with that of MHC class I HC. The abnormalities we have found in the APM in FMCs may cause a defective processing of some tumor antigens

    The H{\alpha} Luminosity Function of Galaxies at z {\sim} 4.5

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    We present the H{\alpha} luminosity function (LF) derived from a large sample of Lyman break galaxies at z {\sim} 4.5 over the GOODS-South and North fields. This study makes use of the new, full-depth Spitzer/IRAC [3.6] and [4.5] imaging from the GOODS Re-ionization Era wide-Area Treasury from the Spitzer program. The H{\alpha} flux is derived from the offset between the continuum flux estimated from the best-fit spectral energy distribution, and the observed photometry in IRAC [3.6]. From these measurements, we build the H{\alpha} LF and study its evolution providing the best constraints of this property at high redshift, where spectroscopy of H{\alpha} is not yet available. Schechter parameterizations of the H{\alpha} LF show a decreasing evolution of {\Phi^\star} with redshift, increasing evolution in L{^\star}, and no significant evolution in the faint-end slope at high z. We find that star formation rates (SFRs) derived from H{\alpha} are higher than those derived from the rest-frame UV for low SFR galaxies but the opposite happens for the highest SFRs. This can be explained by lower mass galaxies (also lower SFR) having, on average, rising star formation histories (SFHs), while at the highest masses the SFHs may be declining. The SFR function is steeper, and because of the excess SFR(H{\alpha}) compared to SFR(UV) at low SFRs, the SFR density estimated from H{\alpha} is higher than the previous estimates based on UV luminosities.Comment: Astrophysical Journal, Accepted, 17 pages, 16 figure

    The BarYon CYCLE Project (ByCycle): Identifying and Localizing MgII Metal Absorbers with Machine Learning

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    The upcoming ByCycle project on the VISTA/4MOST multi-object spectrograph will offer new prospects of using a massive sample of ∌1\sim 1 million high spectral resolution (RR = 20,000) background quasars to map the circumgalactic metal content of foreground galaxies (observed at RR = 4000 - 7000), as traced by metal absorption. Such large surveys require specialized analysis methodologies. In the absence of early data, we instead produce synthetic 4MOST high-resolution fibre quasar spectra. To do so, we use the TNG50 cosmological magnetohydrodynamical simulation, combining photo-ionization post-processing and ray tracing, to capture MgII (λ2796\lambda2796, λ2803\lambda2803) absorbers. We then use this sample to train a Convolutional Neural Network (CNN) which searches for, and estimates the redshift of, MgII absorbers within these spectra. For a test sample of quasar spectra with uniformly distributed properties (λMgII,2796\lambda_{\rm{MgII,2796}}, EWMgII,2796rest=0.05−5.15\rm{EW}_{\rm{MgII,2796}}^{\rm{rest}} = 0.05 - 5.15 \AA, SNR=3−50\rm{SNR} = 3 - 50), the algorithm has a robust classification accuracy of 98.6 per cent and a mean wavelength accuracy of 6.9 \AA. For high signal-to-noise spectra (SNR>20\rm{SNR > 20}), the algorithm robustly detects and localizes MgII absorbers down to equivalent widths of EWMgII,2796rest=0.05\rm{EW}_{\rm{MgII,2796}}^{\rm{rest}} = 0.05 \AA. For the lowest SNR spectra (SNR=3\rm{SNR=3}), the CNN reliably recovers and localizes EWMgII,2796rest_{\rm{MgII,2796}}^{\rm{rest}} ≄\geq 0.75 \AA\, absorbers. This is more than sufficient for subsequent Voigt profile fitting to characterize the detected MgII absorbers. We make the code publicly available through GitHub. Our work provides a proof-of-concept for future analyses of quasar spectra datasets numbering in the millions, soon to be delivered by the next generation of surveys.Comment: 13 pages, 9 figures, 1 table. Accepted for publication in MNRA

    Functionalization of gold nanostars with cationic ß-cyclodextrin-based polymer for drug co-loading and SERS monitoring

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    Gold nanostars (AuNSs) exhibit modulated plasmon resonance and have a high SERS enhancement factor. However, their low colloidal stability limits their biomedical application as a nanomaterial. Cationic ß-cyclodextrin-based polymer (CCD/P) has low cytotoxicity, can load and transport drugs more efficiently than the corresponding monomeric form, and has an appropriate cationic group to stabilize gold nanoparticles. In this work, we functionalized AuNSs with CCD/P to load phenylethylamine (PhEA) and piperine (PIP) and evaluated SERS-based applications of the products. PhEA and PIP were included in the polymer and used to functionalize AuNSs, forming a new AuNS-CCD/P-PhEA-PIP nanosystem. The system was characterized by UV–VIS, IR, and NMR spectroscopy, TGA, SPR, DLS, zeta potential analysis, FE-SEM, and TEM. Additionally, Raman optical activity, SERS analysis and complementary theoretical studies were used for characterization. Minor adjustments increased the colloidal stability of AuNSs. The loading capacity of the CCD/P with PhEA-PIP was 95 ± 7%. The physicochemical parameters of the AuNS-CCD/P-PhEA-PIP system, such as size and Z potential, are suitable for potential biomedical applications Raman and SERS studies were used to monitor PhEA and PIP loading and their preferential orientation upon interaction with the surface of AuNSs. This unique nanomaterial could be used for simultaneous drug loading and SERS-based detection
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