4,021 research outputs found
Property B: Two-Coloring Non-Uniform Hypergraphs
No full textThe following is a classical question of Erdős (Nordisk Matematisk Tidskrift, 1963) and of Erdős and Lovász (Colloquia Mathematica Societatis János Bolyai, vol. 10, 1975). Given a hypergraph ℱ with minimum edge-size k, what is the largest function g(k) such that if the expected number of monochromatic edges in ℱ is at most g(k) when the vertices of ℱ are colored red and blue randomly and independently, then we are guaranteed that ℱ is two-colorable? Duraj, Gutowski and Kozik (ICALP 2018) have shown that g(k) ≥ Ω(log k). On the other hand, if ℱ is k-uniform, the lower bound on g(k) is much higher: g(k) ≥ Ω(√{k / log k}) (Radhakrishnan and Srinivasan, Rand. Struct. Alg., 2000). In order to bridge this gap, we define a family of locally-almost-uniform hypergraphs, for which we show, via the randomized algorithm of Cherkashin and Kozik (Rand. Struct. Alg., 2015), that g(k) can be much higher than Ω(log k), e.g., 2^Ω(√{log k}) under suitable conditions
Bactrocera (Bactrocera) digressa Radhakrishnan (in Drew & Romig 2013
No full textBactrocera (Bactrocera) digressa Radhakrishnan Bactrocera (Bactrocera) digressa Radhakrishnan, 1999: 1. Bactrocera (Daculus) yercaudiae Drew (in Drew & Raghu, 2002) 2002: 346. (synonymised by David & Ramani, 2011). Bactrocera (Daculus) digressa Radhakrishnan (in Drew & Romig, 2013: 199). Bactrocera (Bactrocera) digressa Radhakrishnan (in Hancock, 2015: 42). Material examined: 5♀♀, INDIA, Karnataka, Gowribidanur, Kolar, 23.vii. 2007, Naveen Kumar, V., 1♂, INDIA, Karnataka, Bangalore, Attur farm, 18.ii.2013, David, K. J., 1♂, INDIA, Karnataka, Bangalore, Hebbal, 13.ii.2013, David, K. J., 1♂, INDIA, Karnataka, Bangalore, Hebbal, 30.xi.2012, David, K. J. (NBAIR). Diagnosis: Male with epandrium and surstyli oval in outline (posterior view) (Fig. 5H), Lateral surstylus shorter than epandrium; posterior lobe of surstylus blunt (in profile view), curved in, as long as anterior lobe (Fig. 3H). Proctiger membranous, quadrate and smaller than epandrium (Fig. 3H). Medial surstylus, longer than lateral surstylus with a pair of thick prensisetae (Fig. 5H). Phallus 3.5 mm long, excluding glans (0.4 mm); 0.75 of glans sclerotised with unpatterned praeputium; subapical lobe and basal lobe present (Fig. 8H). Female with reddishbrown, dorsoventrally flattened oviscape (1.05 mm); eversible membrane (1.06 mm) with spicules on distal end having 1̄3 sharp projections (Fig. 11F); aculeus short (0.9 mm) with bifid apex and four pairs of preapical setae (Fig. 13F); two black convoluted berry shaped spermathecae (Fig. 15E).Published as part of David, K. J. & Ramani, S., 2019, New species, redescriptions and phylogenetic revision of tribe Dacini (Diptera: Tephritidae: Dacinae) from India based on morphological characters, pp. 101-146 in Zootaxa 4551 (2) on page 118, DOI: 10.11646/zootaxa.4551.2.1, http://zenodo.org/record/262263
Dr Radhakrishnan as a Philosopher
No full textDr Radhakrishnan’s thinking was Upanishadic. He also firmly believed in the birth of a new order based on ancient Indian wisdom. Drawing his inspiration from the Vedas, the Upanisads and the Gita, Radhakrishnan believed that humanity must become one. What kind of religion did Radhakrishnan advocate? Not a credal or dogmatic one, not an intellectual theology disputing over dogmas and contemplations. Radhakrishnan takes pride in the fact that Hinduism is not bound up with a creed or a dogma, with a founder – prophet or a historical personality, with a book like the Bible or the Quran, but a “persistent search for truth on the basis of a continuously renewed experience”. Radhakrishnan, as an ardent Hindu, could not transcend Hinduism itself. He was respectful of all religions, but it is ultimately Hindu standards by which he judged other religions. Hinduism was always for him the ideal religion, of course, a Hinduism re-interpreted, purged of all that he found distasteful in it. That President Radhakrishnan was a dhvajasthambalam in the temple of our nation’s consciousness: upright and resplendent in rough weather and fair, inspiring us to a higher purpose. K R Srinivas Iyengar noted that without the reserves of the spirit, the inner poise, the hidden fire, all other endowments cannot count for much. And the spirit that moved and sustained our ancient Indian Rishis and Acharyas is not foreign to Professor Radhakrishna
Bactrocera (Bactrocera) digressa Radhakrishnan, s.str.
No full textBactrocera (Bactrocera) digressa Radhakrishnan Bactrocera (Bactrocera) digressa Radhakrishnan, 1999. Rec.Zool.Surv. India, 97(4):1. Holotype ♀. India (Tamil Nadu: Salem dist., Shevroy Hills, Semmanathan) (ZSI) [not examined] Bactrocera (Daculus) yercaudiae Drew, 2002. Raffles Bull.Zool., 50(2): 346. Holotype ♂. India (Tamil Nadu: Yercaud, 15 Km from Yercaud) (BMNH) [not examined]; syn.nov. Material examined INDIA: Karnataka: 11 ♂, Bangalore, 916m, 10.vii.1989, S. Ramani; 2 ♂, same data except 11.vii.1989; 1 ♂, same data except 4.ii.1989; 2 ♂, same data except 3.vii.1988, G. Bhat; 3 ♂, Bangalore, Hessaraghatta, 916m, 14.iii.1987, G. Bhat; 3 ♂ same data except 23.i.1988; 2 ♂ same data except 9.vii.1988; 2 ♂, 1♀, Bangalore, GKVK, 4.ii.2008, David, K. J.; 1 ♂, same data except 20.i.2008; 1 ♂, same data except 8.vi.2008, Sudha, M.; 1 ♂, Gouribidanur, 29.vi.2009, Praveen; 1 ♂, Mandya, 24-30.vii.1989, Gubbaiah; 2 ♂, Tamil Nadu, Yercaud, 3.vii.1992, S. Ramani (UASB); 2 ♀, Karnataka, Gowribidanur, Kolar, 23.vii.07, Naveen Kumar (NBAII). Radhakrishnan (1999) described Bactrocera digressa based on two females collected from Salem district, Tamil Nadu. The diagnostic characters of the species are reddish brown scutum, bifid aculeus tip, absence of acrostichal and anterior supra-alar setae. Later, Drew and Raghu (2002) described Bactrocera (Daculus) yercaudiae based on males collected from Yercaud, Tamil Nadu and Bangalore which responded to cue lure. Perusal of original description of the two species showed complete congruence of characters except costal band, which was mentioned as confluent with vein R 2+ 3 in Bactrocera digressa and slightly overlapping R in B. yercaudiae. Material mentioned above which were keyed out as Bactrocera yercaudiae were examined to confirm the identity. Examination of aculeus tip of the females revealed that it has a bifid aculeus and all the characters are in concordance with that of B. digressa except for a slightly overlapping costal band which might have been overlooked by Radhakrishnan (1999) because it is very faint beyond vein R 2+3. Hence we propose B. yercaudiae as a junior synonymn of B. digressa. Since all the Asian species in subgenus Daculus are aberrant Bactrocera s.str. and true Daculus are African, B. digressa is retained in subgenus Bactrocera (Copeland et al., 2004). As per ICZN rules, Bactrocera digressa Radhakrishnan is the valid name. Three females have been reared from fruits of Alangium lamarkii collected from Yercaud, Tamil Nadu and are deposited in BMNH (Ian M. White, pers. comm.)Published as part of David, K. J. & Ramani, S., 2011, An illustrated key to fruit flies (Diptera: Tephritidae) from Peninsular India and the Andaman and Nicobar Islands, pp. 1-31 in Zootaxa 3021 on page 1
V. Radhakrishnan—Scientist Par Excellence
No full text56-57Prof. V.
Radhakrishnan, who entered the heavenly abode on the 3rd of March 2011, was
fondly known as RAD to all his friends. He was the Director of the Raman
Research Institute, Bangalore
from 1972 to 1994, and a distinguished astrophysicist in his own right
Distance-Preserving Subgraphs of Interval Graphs
No full textWe consider the problem of finding small distance-preserving subgraphs of undirected, unweighted interval graphs that have k terminal vertices. We show that every interval graph admits a distance-preserving subgraph with O(k log k) branching vertices. We also prove a matching lower bound by exhibiting an interval graph based on bit-reversal permutation matrices. In addition, we show that interval graphs admit subgraphs with O(k) branching vertices that approximate distances up to an additive term of +1
Tight Bounds for Communication-Assisted Agreement Distillation
No full textSuppose Alice holds a uniformly random string X in {0,1}^N and Bob holds a noisy version Y of X where each bit of X is flipped independently with probability epsilon in [0,1/2]. Alice and Bob would like to extract a common random string of min-entropy at least k. In this work, we establish the communication versus success probability trade-off for this problem by giving a protocol and a matching lower bound (under the restriction that the string to be agreed upon is determined by Alice's input X). Specifically, we prove that in order for Alice and Bob to agree on a common string with probability 2^{-gamma k} (gamma k >= 1), the optimal communication (up to o(k) terms, and achievable for large N) is precisely (C *(1-gamma) - 2 * sqrt{ C * (1-C) gamma}) * k, where C := 4 * epsilon * (1-epsilon). In particular, the optimal communication to achieve Omega(1) agreement probability approaches 4 * epsilon * (1-epsilon) * k.
We also consider the case when Y is the output of the binary erasure channel on X, where each bit of Y equals the corresponding bit of X with probability 1-epsilon and is otherwise erased (that is, replaced by a "?"). In this case, the communication required becomes (epsilon * (1-gamma) - 2 * sqrt{ epsilon * (1-epsilon) * gamma}) * k. In particular, the optimal communication to achieve Omega(1) agreement probability approaches epsilon * k, and with no communication the optimal agreement probability approaches 2^{- (1-sqrt{1-epsilon})/(1+sqrt{1-epsilon}) * k}.
Our protocols are based on covering codes and extend the approach of (Bogdanov and Mossel, 2011) for the zero-communication case. Our lower bounds rely on hypercontractive inequalities. For the model of bit-flips, our argument extends the approach of (Bogdanov and Mossel, 2011) by allowing communication; for the erasure model, to the best of our knowledge the needed hypercontractivity statement was not studied before, and it was established (given our application) by (Nair and Wang 2015). We also obtain information complexity lower bounds for these tasks, and together with our protocol, they shed light on the recently popular "most informative Boolean function" conjecture of Courtade and Kumar
ERp44 mediates a thiol-independent retention of formylglycine-generating enzyme in the endoplasmic reticulum
No full textMariappan M, Radhakrishnan K, Dierks T, Schmidt B, von Figura K. ERp44 mediates a thiol-independent retention of formylglycine-generating enzyme in the endoplasmic reticulum. JOURNAL OF BIOLOGICAL CHEMISTRY. 2008;283(10):6375-6383.Inside the endoplasmic reticulum (ER) formylglycine-generating enzyme (FGE) catalyzes in newly synthesized sulfatases the post-translational oxidation of a specific cysteine. Thereby formylglycine is generated, which is essential for sulfatase activity. Here we show that ERp44 interacts with FGE forming heterodimeric and, to a lesser extent, also heterotetrameric and octameric complexes, which are stabilized through disulfide bonding between cysteine 29 of ERp44 and cysteines 50 and 52 in the N-terminal region of FGE. ERp44 mediates FGE retrieval to the ER via its C-terminal RDEL signal. Increasing ERp44 levels by overexpression enhances and decreasing ERp44 levels by silencing reduces ER retention of FGE. Suppressing disulfide bonding by mutating the critical cysteines neither abrogates ERp44.FGE complex formation nor interferes with ERp44-mediated retention of FGE, indicating that noncovalent interactions between ERp44 and FGE are sufficient to mediate ER retention. The N-terminal region of FGE harboring Cys(50) and Cys(52) is dispensible for catalytic activity in vitro but required for FGE-mediated activation of sulfatases in vivo. This in vivo activity is affected neither by overexpression nor by silencing of ERp44, indicating that a further ER component interacting with the N-terminal extension of FGE is critical for sulfatase activation
sj-docx-1-tim-10.1177_01423312221147553 – Supplemental material for An enhanced dynamic soft sensor–based online estimation of missing data for water distribution system with inherent disturbances
No full textSupplemental material, sj-docx-1-tim-10.1177_01423312221147553 for An enhanced dynamic soft sensor–based online estimation of missing data for water distribution system with inherent disturbances by K Mohamed Hussain, N Sivakumaran, S Sankaranarayanan, TK Radhakrishnan and G Swaminathan in Transactions of the Institute of Measurement and Control</p
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