A Patchwork of memories 1911-1997

Memoir describes her life in Germany, her decision to leave Germany after the death of her parents, and to work in the United States in 1934. Detailed description of every day life in Germany (after World War I) and in the United States, and later of various travels all over the world. Also mentions her German-Jewish ancestors on her maternal side (great-great-grandparents: Moritz and Fanny Hertz, great-grandmother: Helene Hertz nee Orthenberger), who had a textile business.

A predatory patchwork:membrane and surface structures of Bdellovibrio bacteriovorus

Predatory Bdellovibrio bacteriovorus bacteria are remarkable in that they attach to, penetrate and digest other Gram-negative bacteria, living and replicating within them until all resources are exhausted, when they escape the prey ghost to invade fresh prey. Remarkable remodeling of both predator and prey cell occurs during this process to allow the Bdellovibrio to exploit the intracellular niche they have worked so hard to enter, keeping the prey "bdelloplast" intact until the end of predatory growth. If one views motile non-predatory bacteria in a light microscope, one is immediately struck by how rare it is for bacteria to collide. This highlights how the cell surface of Bdellovibrio must be specialized and adapted to allow productive collisions and further to allow entry into the prey periplasm and subsequent secretion of hydrolytic enzymes to digest it. Bdellovibrio can, however, also be made to grow artificially without prey; thus, they have a large genome containing both predatory genes and genes for saprophytic heterotrophic growth. Thus, the membrane and outer surface layers are a patchwork of proteins encompassing not only those that have a sole purpose in heterotrophic growth but also many more that are specialized or employed to attach to, enter, remodel, kill and ultimately digest prey cells. There is much that is as yet not understood, but molecular genetic and post-genomic approaches to microbial physiology have enhanced the pioneering biochemical work of four decades ago in characterizing some of the key events and surface protein requirements for prey attack.

Climate impact research: beyond patchwork

Despite significant progress in climate impacts research, the narratives that science can presently piece together of a 2-, 3-, 4-, or 5-degree warmer world remain fragmentary. Here we briefly review past undertakings to comprehensively characterize and quantify climate impacts based on multi-model approaches. We then report on the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), a community-driven effort to systematically compare impacts models across sectors and scales, and to quantify the uncertainties along the chain from greenhouse gas emissions and climate input data to the modelling of climate impacts themselves. We show how ISI-MIP and similar efforts can substantially advance the science relevant to impacts, adaptation and vulnerability, and we outline the steps that need to be taken in order to make the most of available modelling tools. We discuss pertinent limitations of these methods and how they could be tackled. We argue that it is time to consolidate the current patchwork of impacts knowledge through integrated cross-sectoral assessments, and that the climate impacts community is now in a favourable position to do so.

Robust patchwork-based embedding and decoding scheme for digital audio watermarking

This paper presents a novel patchwork-based embedding and decoding scheme for digital audio watermarking. At the embedding stage, an audio segment is divided into two subsegments and the discrete cosine transform (DCT) coefficients of the subsegments are computed. The DCT coefficients related to a specified frequency region are then partitioned into a number of frame pairs. The DCT frame pairs suitable for watermark embedding are chosen by a selection criterion and watermarks are embedded into the selected DCT frame pairs by modifying their coefficients, controlled by a secret key. The modifications are conducted in such a way that the selection criterion used at the embedding stage can be applied at the decoding stage to identify the watermarked DCT frame pairs. At the decoding stage, the secret key is utilized to extract watermarks from the watermarked DCT frame pairs. Compared with existing patchwork watermarking methods, the proposed scheme does not require information of which frame pairs of the watermarked audio signal enclose watermarks and is more robust to conventional attacks.

Patchwork-based stereo audio watermarking against de-synchronization attack

Audio watermarking schemes using patchworkbased algorithm have good robustness against majority of the watermarking attacks. However, these watermarking schemes are vulnerable to de-synchronization attack. This paper proposes a patchwork-based watermarking scheme for stereo audio signals to address this problem. To improve the robustness, the proposed method exploits the similarities of both channels in the stereo audio signals. Given a stereo audio signal, we first compute the discrete cosine transform (DCT) of both channels, which gives two sets of DCT coefficients. Then DCT segments are formed form DCT coefficients belong to a certain frequency range. The DCT segment formation is determined by a pseudonoise (PN) sequence which acts as a secret key. Then watermark bits are embedded into DCT segments by modifying the DCT coefficients. In the decoding process the secret key is used to extract the watermark bits embedded in the DCT segments. Simulation results illustrate the effectiveness of the proposed method against de-synchronization attack, compared to latest patchwork-based audio watermarking scheme. Besides, the proposed algorithm also gives better robustness against other conventional attacks.

Analysis of a patchwork-based audio watermarking scheme

Recently, a patchwork-based audio watermarking scheme has been proposed in [1], which embeds watermarks by modifying the means of absolute-valued discrete cosine transform (DCT) coefficients corresponding to suitable fragments. This audio watermarking scheme is more robust to common attacks than the existing counterparts. In this paper, we presents a detailed analysis of this audio watermarking scheme. We first derive a probability density function (pdf) of a random variable corresponding to the mean of an absolute-valued DCT fragment. Then, based on the obtained pdf, we show how watermarking parameters affect the performance of the concerned audio watermarking scheme. The analysis result provides a guideline for the selection of watermarking parameters. The effectiveness of our analysis is verified by simulations using a large number of real-world audio segments.

Robust patchwork-based watermarking method for stereo audio signals

This paper presents a patchwork-based watermarking method for stereo audio signals, which exploits the similarity of the two sound channels of stereo signals. Given a segment of stereo signal, we first compute the discrete Fourier transforms (DFTs) of the two sound channels, which yields two sets of DFT coefficients. The DFT coefficients corresponding to certain frequency range are divided into multiple subsegment pairs and a criterion is proposed to select those suitable for watermark embedding. Then a watermark is embedded into the selected subsegment pairs by modifying their DFT coefficients. The exact way of modification is determined by a secret key, the watermark to be embedded, and the DFT coefficients themselves. In the decoding process, the subsegment pairs containing watermarks are identified by another criterion. Then the secret key is used to extract the watermark from the watermarked subsegments. Compared to the existing patchwork methods for audio watermarking, the proposed method does not require knowledge of which segments of the watermarked audio signal contain watermarks and is more robust to conventional attacks.

Patchwork-based audio watermarking method robust to de-synchronization attacks

This paper presents a patchwork-based audio watermarking method to resist de-synchronization attacks such as pitch-scaling, time-scaling, and jitter attacks. At the embedding stage, the watermarks are embedded into the host audio signal in the discrete cosine transform (DCT) domain. Then, a set of synchronization bits are implanted into the watermarked signal in the logarithmic DCT (LDCT) domain. At the decoding stage, we analyze the received audio signal in the LDCT domain to find the scaling factor imposed by an attack. Then, we modify the received signal to remove the scaling effect, together with the embedded synchronization bits. After that, watermarks are extracted from the modified signal. Simulation results show that at the embedding rate of 10 bps, the proposed method achieves 98.9% detection rate on average under the considered de-synchronization attacks. At the embedding rate of 16 bps, it can still obtain 94.7% detection rate on average. So, the proposed method is much more robust to de-synchronization attacks than other patchwork watermarking methods. Compared with the audio watermarking methods designed for tackling de-synchronization attacks, our method has much higher embedding capacity.

Panama patchwork: poems,

"Seventh thousand."

Panama patchwork; poems,

Mode of access: Internet.

Panama patchwork /

Mode of access: Internet.

The patchwork girl of Oz,

A boy, a patchwork girl, and a glass cat go on a mission to find the ingredients for a charm which will transform some people turned to marble.