On the Reversibility of Newton-Raphson Root-Finding Method

Reversibility of a computational method is the ability to execute the method forward as well as backward. Reversible computational methods are generally useful in undoing incorrect computation in a speculative execution setting designed for efficient parallel processing. Here, reversibility is explored of a common component in scientific codes, namely, the Newton-Raphson root-finding method. A reverse method is proposed that is aimed at retracing the sequence of points that are visited by the forward method during forward iterations. When given the root, along with the number of iterations, of the forward method, this reverse method is aimed at backtracking along the reverse sequence of points to finally recover the original starting point of the forward method. The operation of this reverse method is illustrated on a few example functions, serving to highlight the method's strengths and shortcomings

CPW Fed T-Shaped Wearable Antenna for ISM Band, Wi-Fi, WiMAX, WLAN and Fixed Satellite Service Applications

The placement of wearable products integrated with telecommunication systems is having a good impact on healthcare communication all over the world. Embedded communication devices like antennas and RF devices are helping doctors to assess the condition of patients from remote locations. The present work deals with the design and development of a coplanar waveguide fed wearable antenna for ISM band (2.4–2.5 GHz), Wi-Fi, WLAN (2.4–2.48 GHz), WiMAX (3.4–3.6 GHz), and fixed satellite service (3.6–3.7 GHz and 9–11.5 GHz) applications. The designed antenna on jeans substrate (50 × 40 × 1.6 mm) provides a 1.7 GHz bandwidth with a gain of 4.6 dB. A parametric study of different fabrics and the performance characteristics of bending angles are also provided in this work from the application point of view. The simulated results obtained from CST tool and measured results of fabric material based antenna on vector network analyzer are correlated with each other

Morphology of two dimensional fracture surface

We consider the morphology of two dimensional cracks observed in experimental results obtained from paper samples and compare these results with the numerical simulations of the random fuse model (RFM). We demonstrate that the data obey multiscaling at small scales but cross over to self-affine scaling at larger scales. Next, we show that the roughness exponent of the random fuse model is recovered by a simpler model that produces a connected crack, while a directed crack yields a different result, close to a random walk. We discuss the multiscaling behavior of all these models.Comment: slightly revise

A transcriptomic snapshot of early molecular communication between Pasteuria penetrans and Meloidogyne incognita

© The Author(s). 2018Background: Southern root-knot nematode Meloidogyne incognita (Kofoid and White, 1919), Chitwood, 1949 is a key pest of agricultural crops. Pasteuria penetrans is a hyperparasitic bacterium capable of suppressing the nematode reproduction, and represents a typical coevolved pathogen-hyperparasite system. Attachment of Pasteuria endospores to the cuticle of second-stage nematode juveniles is the first and pivotal step in the bacterial infection. RNA-Seq was used to understand the early transcriptional response of the root-knot nematode at 8 h post Pasteuria endospore attachment. Results: A total of 52,485 transcripts were assembled from the high quality (HQ) reads, out of which 582 transcripts were found differentially expressed in the Pasteuria endospore encumbered J2 s, of which 229 were up-regulated and 353 were down-regulated. Pasteuria infection caused a suppression of the protein synthesis machinery of the nematode. Several of the differentially expressed transcripts were putatively involved in nematode innate immunity, signaling, stress responses, endospore attachment process and post-attachment behavioral modification of the juveniles. The expression profiles of fifteen selected transcripts were validated to be true by the qRT PCR. RNAi based silencing of transcripts coding for fructose bisphosphate aldolase and glucosyl transferase caused a reduction in endospore attachment as compared to the controls, whereas, silencing of aspartic protease and ubiquitin coding transcripts resulted in higher incidence of endospore attachment on the nematode cuticle. Conclusions: Here we provide evidence of an early transcriptional response by the nematode upon infection by Pasteuria prior to root invasion. We found that adhesion of Pasteuria endospores to the cuticle induced a down-regulated protein response in the nematode. In addition, we show that fructose bisphosphate aldolase, glucosyl transferase, aspartic protease and ubiquitin coding transcripts are involved in modulating the endospore attachment on the nematode cuticle. Our results add new and significant information to the existing knowledge on early molecular interaction between M. incognita and P. penetrans.Peer reviewedFinal Published versio

Polymorphisms of TNF-enhancer and gene for FcγRIIa correlate with the severity of falciparum malaria in the ethnically diverse Indian population

<p>Abstract</p> <p>Background</p> <p>Susceptibility/resistance to <it>Plasmodium falciparum </it>malaria has been correlated with polymorphisms in more than 30 human genes with most association analyses having been carried out on patients from Africa and south-east Asia. The aim of this study was to examine the possible contribution of genetic variants in the <it>TNF </it>and <it>FCGR2A </it>genes in determining severity/resistance to <it>P. falciparum </it>malaria in Indian subjects.</p> <p>Methods</p> <p>Allelic frequency distribution in populations across India was first determined by typing genetic variants of the <it>TNF </it>enhancer and the <it>FCGR2A </it>G/A SNP in 1871 individuals from 55 populations. Genotyping was carried out by DNA sequencing, single base extension (SNaPshot), and DNA mass array (Sequenom). Plasma TNF was determined by ELISA. Comparison of datasets was carried out by Kruskal-Wallis and Mann-Whitney tests. Haplotypes and LD plots were generated by PHASE and Haploview, respectively. Odds ratio (OR) for risk assessment was calculated using EpiInfo™ version 3.4.</p> <p>Results</p> <p>A novel single nucleotide polymorphism (SNP) at position -76 was identified in the <it>TNF </it>enhancer along with other reported variants. Five <it>TNF </it>enhancer SNPs and the <it>FCGR2A </it>R131H (G/A) SNP were analyzed for association with severity of <it>P. falciparum </it>malaria in a malaria-endemic and a non-endemic region of India in a case-control study with ethnically-matched controls enrolled from both regions. <it>TNF </it>-1031C and -863A alleles as well as homozygotes for the TNF enhancer haplotype CACGG (-1031T>C, -863C>A, -857C>T, -308G>A, -238G>A) correlated with enhanced plasma TNF levels in both patients and controls. Significantly higher TNF levels were observed in patients with severe malaria. Minor alleles of -1031 and -863 SNPs were associated with increased susceptibility to severe malaria. The high-affinity IgG2 binding FcγRIIa AA (131H) genotype was significantly associated with protection from disease manifestation, with stronger association observed in the malaria non-endemic region. These results represent the first genetic analysis of the two immune regulatory molecules in the context of <it>P. falciparum </it>severity/resistance in the Indian population.</p> <p>Conclusion</p> <p>Association of specific <it>TNF </it>and <it>FCGR2A </it>SNPs with cytokine levels and disease severity/resistance was indicated in patients from areas with differential disease endemicity. The data emphasizes the need for addressing the contribution of human genetic factors in malaria in the context of disease epidemiology and population genetic substructure within India.</p

Nanomechanical sensing using spins in diamond

Nanomechanical sensors and quantum nanosensors are two rapidly developing technologies that have diverse interdisciplinary applications in biological and chemical analysis and microscopy. For example, nanomechanical sensors based upon nanoelectromechanical systems (NEMS) have demonstrated chip-scale mass spectrometry capable of detecting single macromolecules, such as proteins. Quantum nanosensors based upon electron spins of negatively-charged nitrogen-vacancy (NV) centers in diamond have demonstrated diverse modes of nanometrology, including single molecule magnetic resonance spectroscopy. Here, we report the first step towards combining these two complementary technologies in the form of diamond nanomechanical structures containing NV centers. We establish the principles for nanomechanical sensing using such nano-spin-mechanical sensors (NSMS) and assess their potential for mass spectrometry and force microscopy. We predict that NSMS are able to provide unprecedented AC force images of cellular biomechanics and to, not only detect the mass of a single macromolecule, but also image its distribution. When combined with the other nanometrology modes of the NV center, NSMS potentially offer unparalleled analytical power at the nanoscale.Comment: Errors in the stress susceptibility parameters present in the original arXiv version have been correcte

Spin Glass and Antiferromagnetic Behaviour in a Diluted fcc Antiferromagnet

We report on a Monte Carlo study of a diluted Ising antiferromagnet on a fcc lattice. This is a typical model example of a highly frustrated antiferromagnet, and we ask, whether sufficient random dilution of spins does produce a spin glass phase. Our data strongly indicate the existence of a spin glass transition for spin--concentration $p<0.75$: We find a divergent spin glass susceptibility and a divergent spin glass correlation length, whereas the antiferromagnetic correlation length saturates in this regime. Furthermore, we find a first order phase transition to an antiferromagnet for $1\ge p>0.85$, which becomes continuous in the range $0.85>p>0.75$. Finite size scaling is employed to obtain critical exponents. We compare our results with experimental systems as diluted frustrated antiferromagnets as ${\rm Zn_{1-p}Mn_{p}Te}$.Comment: 29 pages (revtex) and 10 figures uuencoded and Z-compresse

New appraisal values of travel time saving and reliability in Great Britain

© 2017, The Author(s). This paper provides an overview of the study ‘Provision of market research for value of time savings and reliability’ undertaken by the Arup/ITS Leeds/Accent consortium for the UK Department for Transport (DfT). The paper summarises recommendations for revised national average values of in-vehicle travel time savings, reliability and time-related quality (e.g. crowding and congestion), which were developed using willingness-to-pay (WTP) methods, for a range of modes, and covering both business and non-work travel purposes. The paper examines variation in these values by characteristics of the traveller and trip, and offers insights into the uncertainties around the values, especially through the calculation of confidence intervals. With regards to non-work, our recommendations entail an increase of around 50% in values for commute, but a reduction of around 25% for other non-work—relative to previous DfT ‘WebTAG’ guidance. With regards to business, our recommendations are based on WTP, and thus represent a methodological shift away from the cost saving approach (CSA) traditionally used in WebTAG. These WTP-based business values show marked variation by distance; for trips of less than 20miles, values are around 75% lower than previous WebTAG values; for trips of around 100miles, WTP-based values are comparable to previous WebTAG; and for longer trips still, WTP-based values exceed those previously in WebTAG