Multiple-description iterative coding image watermarking

To embed the multiple watermarks is a way to increase robustness in image watermark. The limitation of embedding multiple watermarks is that the limited capacity of an image severely limits the size of the watermark. Multiple-description coding is a good candidate to solve this limitation by trading off between transmission bandwidth and bit error rate. Traditionally, multiple-description coding is considered in on-off channels where channels are not marred by bit errors but occasional connection outages such as dropped packets. To apply multiple-description coding in image watermarking, we need a form of multiple-description coding for noisy channels instead of on-off channels. In this paper, we propose to add iterative coding in multiple description in order to combat bit errors in image watermarking. We call this method multiple-description iterative coding (MDIC) image watermarking. We tested our system on six images. On average, bit error did not happen until we compressed the image in JPEG to PSNR 36.97 dB. We concluded that MDIC was a very good way to increase robustness for image watermarking. (C) 2009 Elsevier Inc. All rights reserved

INTER-BLOCK DIRECT-SEQUENCE AND FREQUENCY-HOP SPREAD SPECTRUM IMAGE WATERMARKS

One of the most popular image watermark embedding methods is the spread spectrum (SS) technique. The original SS technique proposed by Cox et al. divides the image into NxN blocks and the pseudo-noise (PN) sequence generated from each watermark bit is embedded in one of the blocks. Since there is only one watermark bit embedded in each block, we call this method "intra-block" method. In this paper, we proposed a new approach called "inter-block" method. In our method, vie embedded the PN sequence from one watermark bit into several different blocks as opposed to just one block. In other words, we comprehensively studied the effects of different embedding locations in this paper and to the best of our knowledge, whereas this study has not been done before. To thoroughly study the differences between the new "inter-block" method and the old "intra-block" method, we subjected both methods to various watermark attacks and compared their performances. From the experiments, we found that "inter-block" techniques perform better against all attacks

Mutation of a nitrate transporter, AtNRT1 : 4, results in a reduced petiole nitrate content and altered leaf development

Unlike nitrate uptake of plant roots, less is known at the molecular level about how nitrate is distributed in various plant tissues. In the present study, characterization of the nitrate transporter, AtNRT1:4, revealed a special role of petiole in nitrate homeostasis. Electrophysiological studies using Xenopus oocytes showed that AtNRT1:4 was a low-affinity nitrate transporter. Whole-mount in situ hybridization and RT-PCR demonstrated that AtNRT1:4 was expressed in the leaf petiole. In the wild type, the leaf petiole had low nitrate reductase activity, but a high nitrate content, indicating that it is the storage site for nitrate, whereas, in the atnrt1:4 mutant, the petiole nitrate content was reduced to 50-64% of the wild-type level. Moreover, atnrt1:4 mutant leaves were wider than wild-type leaves. This study revealed a critical role of AtNRT1:4 in regulating leaf nitrate homeostasis, and the deficiency of AtNRT1: 4 can alter leaf development

Use of the WHO Access, Watch, and Reserve classification to define patterns of hospital antibiotic use (AWaRe): an analysis of paediatric survey data from 56 countries

Background Improving the quality of hospital antibiotic use is a major goal of WHO's global action plan to combat antimicrobial resistance. The WHO Essential Medicines List Access, Watch, and Reserve (AWaRe) classification could facilitate simple stewardship interventions that are widely applicable globally. We aimed to present data on patterns of paediatric AWaRe antibiotic use that could be used for local and national stewardship interventions. Methods 1-day point prevalence survey antibiotic prescription data were combined from two independent global networks: the Global Antimicrobial Resistance, Prescribing, and Efficacy in Neonates and Children and the Global Point Prevalence Survey on Antimicrobial Consumption and Resistance networks. We included hospital inpatients aged younger than 19 years receiving at least one antibiotic on the day of the survey. The WHO AWaRe classification was used to describe overall antibiotic use as assessed by the variation between use of Access, Watch, and Reserve antibiotics, for neonates and children and for the commonest clinical indications. Findings Of the 23 572 patients included from 56 countries, 18305 were children (77.7%) and 5267 were neonates (22.3%). Access antibiotic use in children ranged from 7.8% (China) to 61.2% (Slovenia) of all antibiotic prescriptions. The use of Watch antibiotics in children was highest in Iran (77.3%) and lowest in Finland (23.0%). In neonates, Access antibiotic use was highest in Singapore (100.0%) and lowest in China (24.2%). Reserve antibiotic use was low in all countries. Major differences in clinical syndrome-specific patterns of AWaRe antibiotic use in lower respiratory tract infection and neonatal sepsis were observed between WHO regions and countries. Interpretation There is substantial global variation in the proportion of AWaRe antibiotics used in hospitalised neonates and children. The AWaRe classification could potentially be used as a simple traffic light metric of appropriate antibiotic use. Future efforts should focus on developing and evaluating paediatric antibiotic stewardship programmes on the basis of the AWaRe index. Copyright (C) 2019 The Author(s). Published by Elsevier Ltd