8,874 research outputs found
-supercontinuous functions
No full textsummary:A new class of functions called “-supercontinuous functions” is introduced. Their basic properties are studied and their place in the hierarchy of strong variants of continuity that already exist in the literature is elaborated. The class of -supercontinuous functions properly includes the class of -supercontinuous functions, Tyagi, Kohli, Singh (2013), which in its turn contains the class of -supercontinuous ( clopen continuous) functions, Singh (2007), Reilly, Vamanamurthy (1983), and is strictly contained in the class of -supercontinuous, Kohli, Tyagi, Singh, Aggarwal (2014), which in its turn is properly contained in the class of -supercontinuous functions, Kohli, Singh, Aggarwal (2010)
On optimum stratification with proportional allocation for a class of pareto distributions
No full textCum ./LSTA_A_8828879_O_XML_IMAGES/LSTA_A_8828879_O_ILM0001.gif rule [Singh (1975)] has been suggested in the literature for finding approximately optimum strata boundaries for proportional allocation, when the stratification is done on the study variable. This paper shows that for the class of density functions arising from the Wang and Aggarwal (1984) representation of the Lorenz Curve (or DBV curves in case of inventory theory), the cum ./LSTA_A_8828879_O_XML_IMAGES/LSTA_A_8828879_O_ILM0002.gif rule in place of giving approximately optimum strata boundaries, yields exactly optimum boundaries. It is also shown that the conjecture of Mahalanobis (1952) “. . .an optimum or nearly optimum solutions will be obtained when the expected contribution of each stratum to the total aggregate value of Y is made equal for all strata” yields exactly optimum strata boundaries for the case considered in the paper
Time-Dependent Regulation Of LPS-Induced Neutrophil Activation And Cxcr2 Levels By α1-Antitrypsin
No full textInhibition of Alzheimer's BACE-1 by 2,6-dialkyl-4-chromon-3-yl-1,4-dihydropyridine-3,5-dicarboxylates
No full textAlzheimer’s disease is the most common cause of dementia in the elderly, and no disease-modifying therapy is yet available for this devastating pathology. Deposition of different physicochemical forms of amyloid-β peptides is a critical phase in the pathogenesis of Alzheimer’s disease. β-Site amyloid precursor protein cleaving enzyme 1 (BACE-1) is a major enzyme responsible for amyloid-β production; therefore, inhibition of this enzyme represents a promising approach for the discovery of amyloid-β-lowering agents. In this study, a series of novel 2,6-dialkyl-4-chromon-3-yl-1,4-dihydropyridine-3,5-dicarboxylates (14–23) were synthesized and assessed as BACE-1 inhibitors using the Förster resonance energy transfer-based enzyme assay. Synthesized dihydropyridines exhibited weak-to-relatively-good BACE-1 inhibitory activities. Enzyme inhibitory activities ranged from 6.84 ± 6.62 (23) to 51.32 ± 1.04 (14) percent enzyme inhibitions at the concentration of 10 μM. The structure–activity relationship study showed that the presence of 4-[7-(ethanoyloxy)-4-oxo-4H-chromen-3-yl] moiety at C4 position of dihydropyridine ring (14, 16 and 18) confers higher activity compared with other substitutions at this position. Docking simulation predicted a key H-bond interaction between Asp32 residue and dihydropyridine NH group. Moreover, all docked dihydropyridines made good hydrophobic contacts with S1 and S2 subpockets of BACE-1. A good correlation between estimated binding affinities (pKi) and experimental BACE-1 inhibitory activities at 10 μM was obtained (R 2 = 0.639). The findings of this study suggested that 2,6-dialkyl-4-chromon-3-yl-1,4-dihydropyridine-3,5-dicarboxylates could be promising scaffolds for the discovery of novel BACE-1 inhibitors for management of Alzheimer’s disease
UV generation in a pure-silica holey fiber
No full textWe report supercontinuum generation extending to 300nm in the UV from a pure-silica holey fiber. The broad spectrum was obtained by launching ultra-short pulses (~150fs, 10nJ at 820nm) from an amplified Ti:sapphire laser. The extension of holey-fiber-based supercontinuum generation into the UV should prove to be of immediate application in spectroscopy. By slightly detuning the launch conditions we excited a higher order spatial mode, which produced a narrower supercontinuum, but with enhanced conversion efficiency at a series of blue/UV peaks around 360nm. We present numerical simulations, which suggest that differences in the dispersion profiles between the modes are an important factor in explaining this enhancement. In a related experiment, using the same laser source and fiber, we demonstrate a visible supercontinuum from several subsidiary cores, with distinct colours in each core. The subsidiary cores were excited by an appropriate input coupling. Fabrication of a fiber with a range of core sizes (dispersion profiles) for tailored supercontinuum generation can therefore be envisaged for practical applications
Data mining : the textbook / Charu C. Aggarwal.
No full textcomputer bookfair2016Includes bibliographical references and index.xxix, 734 pages
The Role of Optical Coherence Tomography Angiography in the Diagnosis and Management of Acute Vogt-Koyanagi-Harada Disease
No full textPURPOSE:To report the imaging characteristics of acute Vogt-Koyanagi-Harada (VKH) disease using optical coherence tomography angiography (OCTA).
METHODS: In this prospective study, patients with acute VKH (n = 10; mean age: 30.5 ± 13.43 years) underwent multimodal imaging (baseline and follow-up) using fundus photography, fluorescein angiography (FA), indocyanine green angiography (ICGA), OCT, and OCTA. The OCTA images were analyzed to assess the retinochoroidal vasculature and compared with other imaging techniques.
RESULTS: During the active stage, all eyes showed multiple foci of choriocapillaris flow void that correlated with ICGA. These foci decreased in number and size after initiation of therapy. In one patient, flow void areas reappeared after cessation of therapy without any detectable change on ICGA. This patient soon developed clinical recurrence requiring re-initiation of immunosuppression.
CONCLUSIONS: OCTA allows high-resolution imaging of inflammatory foci suggestive of choriocapillaris hypoperfusion in acute VKH disease non-invasively. OCTA may be very helpful in the follow-up of such patients
Biological pathways in B-cell non-Hodgkin's lymphoma
No full textNon-Hodgkin’s lymphomas have become more prevalent in the past 20 years. They constitute a diverse group of lymphoid tumors that have been understood and classified according to their clinical behaviour, anatomic location, morphology, immunophenotype, cytogenetics, and gene expression profile. Microarray profiling yields information about large number of genes, which can be involved in different functional pathways of importance for the biology of lymphomas.In this thesis, we started to look at major types of B-cell lymphomas by using the microarrays, with the aim to have a macroscopic view of the signaling pathways involved in their biology. Functional signatures such as cell cycle, apoptosis, cytokine-cytokine receptor interaction, T-cell receptor, B-cell receptor (BCR), cell adhesion, and NF-kappaB activation describe multiple dysregulated pathways in lymphomas. The BCR gene expression delineates distinct functional heterogeneity within each lymphoma. In CLL, the BCR genes were positively correlated to the expression of the pathways for CREB, MAPK/ERK5, BCR Signaling and MET. In MCL, the BCR genes were additionally coregulated to GC T-helper cell, integrins, CXCR4 and blood pan-B cell genes. In FL, BCR genes showed positive correlation to the mTOR-, GC B-cell-, Akt- and BCR Signaling-, blood pan B-cell- and ERK5- pathways while in DLBCL they were co-expressed with GC-B-cell, blood pan-B cell and c-myc targets. Interestingly, targets for BLIMP-1, an important transcription factor, were positively correlated to the expression of BCR genes in all the four mentioned lymphomas (Paper I).During unsupervised clustering, we observed that BCR genes and TCL1 oncogene were expressed in the same cluster. Variation in the level of gene array expression of TCL1A was significantly associated with gene signatures recognizing B-cell lymphoma biology, such as germinal center, BCR, NF-êB (and its target genes), death, MAP kinases, TNFR1, TOLL, and IL1R. High expression of TCL1 was related to poor prognosis in CLL and MCL in microarray and immunohistochemistry respectively. (Paper II).Thus, we found in these studies (Paper I and II) that BCR and TCL1 are important to lymphoma biology, while they also define striking heterogeneity within known lymphoma types.The role of somatic hypermutation(SHM) of the B-cell receptor in the lymphoma biology was demonstrated (paperIII); we identified here surrogate markers or genes in the cell machinery that accompany the process. Markers of SHM (such as RAD51C and CDK7) and ongoing SHM (TFDP1 and POLA) are some of the genes involved in DNA repair and replication. CDK7 and RCC1, separately and together, showed prognostic value in Mantle Cell Lymphoma on immunohistochemistry (Paper III).In the end, we narrowed our attention to Follicular Lymphoma (FL) and the microenvironment. Using a unique approach of flow cytometry and automated microscopy scoring in FL, we identified that the clinical outcome was independently predicted by different immune cells: CD4+ T-cells and macrophages were associated with poor prognosis while cytotoxic T-lymphocytes and T-regulatory cells were associated with better prognosis (Paper IV).The results presented in the thesis provide insight and understanding of lymphoma biology that would facilitate discovery of markers of prognostic and hopefully therapeutic importance.List of scientific papersI. Aggarwal M, Sánchez-Beato M, Aggarwal M, Sánchez-Beato M, Gómez-López G, Al-Shahrour F, Martínez N, Rodríguez A, Ruiz-Ballesteros E, Camacho FI, Pérez-Rosado A, de la Cueva P, Artiga MJ, Pisano DG, Kimby E, Dopazo J, Villuendas R, Piris MA (2009). Functional signatures identified in B-cell non-Hodgkin lymphoma profiles. Leuk Lymphoma. 50(10): 1699-708. https://doi.org/10.3109/10428190903189035 II. Aggarwal M, Villuendas R, Gomez G, Rodriguez-Pinilla SM, Sanchez-Beato M, Alvarez D, Martinez N, Rodriguez A, Castillo ME, Camacho FI, Montes-Moreno S, Garcia-Marco JA, Kimby E, Pisano DG, Piris MA (2009). TCL1A expression delineates biological and clinical variability in B-cell lymphoma. Mod Pathol. 22(2): 206-15. https://doi.org/10.1038/modpathol.2008.148 III. Tracey L, Aggarwal M, García-Cosio M, Villuendas R, Algara P, Sánchez-Beato M, Sánchez-Aguilera A, García JF, Rodríguez A, Camacho FI, Martínez N, Ruiz-Ballesteros E, Mollejo M, Piris MA (2008). Somatic hypermutation signature in B-cell low-grade lymphomas. Haematologica. 93(8): 1186-94. https://doi.org/10.3324/haematol.12999 IV. Engelbrekt Wahlin B, Aggarwal M, Montes-Moreno S, Gonzalez LF, Roncador G, Sanchez-Verde L, Christensson B, Sander B, Kimby E (2009). A unifying model of the microenvironment of follicular lymphoma: outcome is predicted by programmed death-1-positive, regulatory, cytotoxic and helper T cells and macrophages. Clinical Cancer Research. [Accepted] https://doi.org/10.1158/1078-0432.CCR-09-2487 V. Ruiz-Vela A, Aggarwal M, de la Cueva P, Treda C, Herreros B, Martín-Pérez D, Dominguez O, Piris MA (2008). Lentiviral (HIV)-based RNA interference screen in human B-cell receptor regulatory networks reveals MCL1-induced oncogenic pathways. Blood. 111(3): 1665-76. https://doi.org/10.1182/blood-2007-09-110601 </p
Improved Lower Bounds for 3-Query Matching Vector Codes
No full textA Matching Vector (MV) family modulo a positive integer m ≥ 2 is a pair of ordered lists U = (u_1, ⋯, u_K) and V = (v_1, ⋯, v_K) where u_i, v_j ∈ ℤ_m^n with the following property: for any i ∈ [K], the inner product ⟨u_i, v_i⟩ = 0 mod m, and for any i ≠ j, ⟨u_i, v_j⟩ ≠ 0 mod m. An MV family is called r-restricted if inner products ⟨u_i, v_j⟩, for all i,j, take at most r different values. The r-restricted MV families are extremely important since the only known construction of constant-query subexponential locally decodable codes (LDCs) are based on them. Such LDCs constructed via matching vector families are called matching vector codes. Let MV(m,n) (respectively MV(m, n, r)) denote the largest K such that there exists an MV family (respectively r-restricted MV family) of size K in ℤ_m^n. Such a MV family can be transformed in a black-box manner to a good r-query locally decodable code taking messages of length K to codewords of length N = m^n.
For small prime m, an almost tight bound MV(m,n) ≤ O(m^{n/2}) was first shown by Dvir, Gopalan, Yekhanin (FOCS'10, SICOMP'11), while for general m, the same paper established an upper bound of O(m^{n-1+o_m(1)}), with o_m(1) denoting a function that goes to zero when m grows. For any arbitrary constant r ≥ 3 and composite m, the best upper bound till date on MV(m,n,r) is O(m^{n/2}), is due to Bhowmick, Dvir and Lovett (STOC'13, SICOMP'14).In a breakthrough work, Alrabiah, Guruswami, Kothari and Manohar (STOC'23) implicitly improve this bound for 3-restricted families to MV(m, n, 3) ≤ O(m^{n/3}).
In this work, we present an upper bound for r = 3 where MV(m,n,3) ≤ m^{n/6 +O(log n)}, and as a result, any 3-query matching vector code must have codeword length of N ≥ K^{6-o(1)}
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