This review covers the toxicology of mercury and its compounds. Special attention is paid to those forms of mercury of current public health concern. Human exposure to the vapor of metallic mercury dates back to antiquity but continues today in occupational settings and from dental amalgam. Health risks from methylmercury in edible tissues of fish have been the subject of several large epidemiological investigations and continue to be the subject of intense debate. Ethylmercury in the form of a preservative, thimerosal, added to certain vaccines, is the most recent form of mercury that has become a public health concern. The review leads to general discussion of evolutionary aspects of mercury, protective and toxic mechanisms, and ends on a note that mercury is still an "element of mystery."

The Toxicology of Mercury and Its Chemical Compounds

Despite its centrality to human thought and practice, aesthetics has for the most part played a petty role in human-computer interaction research. Increasingly, however, researchers attempt to strike a balance between the traditional concerns of human-computer interaction and considerations of aesthetics. Thus, recent research suggests that the visual aesthetics of computer interfaces is a strong determinant of users' satisfaction and pleasure. However, the lack of appropriate concepts and measures of aesthetics may severely constraint future research in this area. To address this issue, we conducted four studies in order to develop a measurement instrument of perceived web site aesthetics. Using exploratory and confirmatory factor analyses we found that users' perceptions consist of two main dimensions, which we termed "classical aesthetics" and "expressive aesthetics". The classical aesthetics dimension pertains to aesthetic notions that presided from antiquity until the 18th century. These notions emphasize orderly and clear design and are closely related to many of the design rules advocated by usability experts. The expressive aesthetics dimension is manifested by the designers' creativity and originality and by the ability to break design conventions. While both dimensions of perceived aesthetic are drawn from a pool of aesthetic judgments, they are clearly distinguishable from each other. Each of the aesthetic dimensions is measured by a five-item scale. The reliabilities, factor structure and validity tests indicate that these items reflect the two perceived aesthetics dimensions adequately.

Assessing dimensions of perceived visual aesthetics of web sites

Two studies considered the interplay between user-perceived usability (i.e., pragmatic attributes), hedonic attributes (e.g., stimulation, identification), goodness (i.e., satisfaction), and beauty of 4 different MP3-player skins. As long as beauty and goodness stress the subjective valuation of a product, both were related to each other. However, the nature of goodness and beauty was found to differ. Goodness depended on both perceived usability and hedonic attributes. Especially after using the skins, perceived usability became a strong determinant of goodness. In contrast, beauty largely depended on identification; a hedonic attribute group, which captures the product's ability to communicate important personal values to relevant others. Perceived usability as well as goodness was affected by experience (i.e., actual usability, usability problems), whereas hedonic attributes and beauty remained stable over time. All in all, the nature of beauty is rather self-oriented than goal-oriented, whereas goodness relates to both.

The interplay of beauty, goodness, and usability in interactive products

Three studies were conducted to ascertain how quickly people form an opinion about web page visual appeal. In the first study, participants twice rated the visual appeal of web homepages presented for 500 ms each. The second study replicated the first, but participants also rated each web page on seven specific design dimensions. Visual appeal was found to be closely related to most of these. Study 3 again replicated the 500 ms condition as well as adding a 50 ms condition using the same stimuli to determine whether the first impression may be interpreted as a 'mere exposure effect' (Zajonc 1980). Throughout, visual appeal ratings were highly correlated from one phase to the next as were the correlations between the 50 ms and 500 ms conditions. Thus, visual appeal can be assessed within 50 ms, suggesting that web designers have about 50 ms to make a good first impression.

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Attention web designers: You have 50 milliseconds to make a good first impression!

Introduction A fundamental objective of cryptography is to enable two persons to communicate over an insecure channel (a public channel such as the internet) in such a way that any other person is unable to recover their message (called the plaintext ) from what is sent in its place over the channel (the ciphertext ). The transformation of the plaintext into the ciphertext is called encryption , or enciphering. Encryption-decryption is the most ancient cryptographic activity (ciphers already existed four centuries b.c.), but its nature has deeply changed with the invention of computers, because the cryptanalysis (the activity of the third person, the eavesdropper, who aims at recovering the message) can use their power. The encryption algorithm takes as input the plaintext and an encryption key K E , and it outputs the ciphertext. If the encryption key is secret, then we speak of conventional cryptography , of private key cryptography , or of symmetric cryptography . In practice, the principle of conventional cryptography relies on the sharing of a private key between the sender of a message (often called Alice in cryptography) and its receiver (often called Bob). If, on the contrary, the encryption key is public, then we speak of public key cryptography . Public key cryptography appeared in the literature in the late 1970s.

/pdf/boolean-models-and-methods-in-mathematics-computer-science-3vbrnbyptk.pdf

Boolean Models and Methods in Mathematics, Computer Science, and Engineering: Boolean Functions for Cryptography and Error-Correcting Codes

The first impressions of web pages presented to users was investigated by using 13 different web pages, three types of scales and 18 participants. Multidimensional analysis of similarity and preference judgements found four important dimensions: beauty, mostly illustrations versus mostly text, overview and structure. Category scales indicated the existence of two factors related to formal aspects and to appeal of the objects, respectively. The best predictor for the overall judgement of the category scales was beauty. Property vector fitting of the multidimensional solutions with the category scales further indicated the importance of beauty for the preference space. Aspects of usability, product design and aesthetics are discussed.

Aesthetics and preferences of web pages

This paper describes new methods for fast correlation attacks, based on the theory of convolutional codes. They can be applied to arbitrary LFSR feedback polynomials, in opposite to the previous methods, which mainly focus on feedback polynomials of low weight. The results improve significantly the few previous results for this general case, and are in many cases comparable with corresponding results for low weight feedback polynomials.

/pdf/improved-fast-correlation-attacks-on-stream-ciphers-via-2vxa5ihpbp.pdf

Improved fast correlation attacks on stream ciphers via convolutional codes

The task of a fast correlation attack is to efficiently restore the initial content of a linear feedback shift register in a stream cipher using a detected correlation with the output sequence. We show that by modeling this problem as the problem of learning a binary linear multivariate polynomial, algorithms for polynomial reconstruction with queries can be modified through some general techniques used in fast correlation attacks. The result is a new and efficient way of performing fast correlation attacks.

https://link.springer.com/content/pdf/10.1007%2F3-540-44598-6_19.pdf

Fast Correlation Attacks through Reconstruction of Linear Polynomials

Fast correlation attacks through reconstruction of linear polynomials

This paper describes new methods for fast correlation attacks on stream ciphers, based on techniques used for constructing and decoding the by now famous turbo codes. The proposed algorithm consists of two parts, a preprocessing part and a decoding part. The preprocessing part identifies several parallel convolutional codes, embedded in the code generated by the LFSR, all sharing the same information bits. The decoding part then finds the correct information bits through an iterative decoding procedure. This provides the initial state of the LFSR.

/pdf/fast-correlation-attacks-based-on-turbo-code-techniques-3rp9o7gxmb.pdf

Fredrik U. Jönsson

Papers

Aesthetics and preferences of web pages

Improved fast correlation attacks on stream ciphers via convolutional codes

Fast Correlation Attacks through Reconstruction of Linear Polynomials

Fast correlation attacks through reconstruction of linear polynomials

Fast Correlation Attacks Based on Turbo Code Techniques