The production of single strand and double strand breaks in DNA in aqueous solution by vacuum UV photons below 10 eV

The mechanisms of break formation in fully hydrated DNA have been investigated using monochromatic photons below 10 eV. This has been achieved by developing a novel 'wet cell' for irradiating DNA in aqueous solution. Our preliminary data show that 7-10 eV photons readily induce strand breaks even though almost all of the energy is absorbed in the water. Therefore, the mechanism for the induction of single and double strand breaks (SSBs and DSBs) most likely involves indirect damage by OH radicals and is substantiated by data from studies in the presence of the OH radical scavenger Tris, which showed a substantial protective effect. The dose-effect curve for DSB induction is seen to be linear, or near-linear, indicating the involvement of 1-hit mediated induction of DSBs. These data point to single-event induction of DSBs being a significant pathway with all radiation types.     

Affordance as context

The concept of affordance is relatively easy to define, but has proved to be remarkably difficult to engineer. This paradox has sparked numerous debates as to its true nature. The discussion presented here begins with a review of the use of the term from which emerges evidence for a two-fold classification—simple affordance and complex affordance. Simple affordance corresponds to Gibson's original formulation, while complex affordances embody such things as history and practice. In trying to account for complex affordance, two contrasting, but complementary philosophical treatments are considered. The first of these is Ilyenkov's account of significances which he claims are ‘ideal’ phenomena. Ideal phenomena occupy are objective characteristics of things and are the product of human purposive activity. This makes them objective, but not independent (of any particular mind or perception) hence their similarity to affordances.

The second perspective is Heidegger's phenomenological treatment of ‘familiarity’ and ‘equipment’. As will be seen, Heidegger has argued that familiarity underpins our ability to cope in the world. A world, in turn, which itself comprises the totality of equipment. We cope by making use of equipment. Despite the different philosophical traditions both Ilyenkov and Heidegger have independently concluded that a thing is identified by its use and that use, in turn, is revealed by way of its affordances/significances. Finally, both authors—Heidegger directly and Ilyenkov indirectly—equate context and use, leading to the conclusion that affordance and context are one and the same.     

一种新型的移动增值服务——动态电话簿

今天的手机采用相对简单的接口就可以进行电话呼叫。虽然相对于传统固定电话拨号略微复杂了一些,但是移动电话接口还是包括了内置电话录和其它崭新的功能。然而,通信远不限于语音通话。现在我们的手机上有文本消息、一键通、图像邮件和多用户游戏。而我们的P C电脑支持即时通信     

The premier CG and A digital media issue

A growing part of the computer graphics field (its science, algorithms, products, and applications) deals with either dynamic situations, digital media, or both. As a result, it's challenging for computing professionals to fully understand, or experience the applications for, dynamic and digital media when the expression of computer graphics is confined to printed articles. IEEE Computer Graphics and Applications has embarked on an experiment in bringing digital media content to our readers-not to replace our print publication but to augment it with a new method of communication. High-quality print articles can do an excellent job of telling the how, but in many instances, digital media can better express the what dimension of understanding graphics. Another goal of CG&A is to provide a professionally reviewed channel for researchers and practitioners of computer graphics. Digital media publication may better serve the needs of a community whose contribution is best expressed or understood through interactive or dynamic content, or whose preferred method of communication isn't the printed word.     

EPLOT: a machine-independent graphics system

EPLOT was designed as an inexpensive and interactive small graphics library to be run on workstations, stand-alone microcomputers and mainframes, or microcomputers used as graphics terminals. It started as a minor extension to the machine-independent UNIX PLOT library but now includes capabilities for menu and mouse operations, animation, and other functions required in student projects. EPLOT allows the easy development and transfer of interactive graphics programs between SUN, MSDOS, Amiga, ATARI, and Apple Macintosh systems. It has played an important role in the philosophy of the computer graphics course offered at the authors' institution. The scope of EPLOT is demonstrated through a series of projects and programs     

Comparison of high-temperature-superconductor and metal-basedresonators

A 50-Ω coplanar waveguide (CPW) resonator designed for a fundamental frequency of about 4.75 GHz was fabricated on LaAlO₃ . Two versions were fabricated: the first using 1.9-μm-thick gold and the second using 0.6-μm-thick YBa₂Cu₃O ₇. The devices were identically packaged and tested at 77 K. It was found that the high-temperature superconductor (HTS) resonator had a surface resistance, R_s, about six to nine times lower than the Au one. At 45 K, the R_s of the HTS resonator decreases by another factor of 4 compared with its 77 K value. Device characteristics for the HTS resonator are presented     

A THEORETICAL AND EXPERIMENTAL INVESTIGATION OF THE CONVECTIVE DRYING OF AUSTRALIAN PINUS RADIATA TIMBER

A series of experiments on the convective drying of Pinus radiata has been undertaken at the CSIRO Division of Forest Products in Australia. This paper uses the experimental results to compare predictions from both a comprehensive mathematical model, which includes wood temperature, moisture content and pressure distributions, and a simplified model (two versions) which assumes constant total pressure. From the- simulations, it is seen that both models adequately predict the overall kinetics of the wood drying process. For a complete understanding of the heat and mass transfer phenomena that occur in wood during drying the comprehensive model is necessary. However, it is computationally long and expensive, and as such, does not suit the practical drying needs of the timber industry in Australia. Consequently, the simplified model, which has acceptable computation time and sufficient accuracy for engineering purposes, enables die wood drying process to be optimised from both performance and economic perspectives.     

Prognostic significance of colony-stimulating factor receptor expression in ipsilateral breast cancer recurrence

The macrophage colony-stimulating factor receptor (CSF-1R), the product of the c-fms proto-oncogene, regulates normal proliferation and differentiation of macrophages and trophoblasts. Recent research found abnormal expression of CSF-1R in human carcinomas of the breast, endometrium, and ovary. Furthermore, activation of CSF-1R by its ligand has been shown to regulate invasiveness and anchorage-independent growth in breast carcinoma cells. To study the significance of CSF-1R expression in breast cancer, we designed a case-controlled immunohistochemical study. We chose 80 patients from a database of 1200 early stage I or II breast cancer patients treated with conservative surgery and radiation therapy. Expression of CSF-1R in the tumors of 40 patients who experienced an ipsilateral breast tumor recurrence (IBTR) as a primary site of relapse were compared with 40 patients who had not experienced an IBTR. The index and control patients were matched by age, clinical stage, nodal status, and follow-up. Paraffin-embedded sections were immunostained with antibodies directed toward CSF-1R. For the CSF-1R antibody, a total of 28 index cases (70%) demonstrated strong staining, whereas only 16 control cases (40%) demonstrated high immunoreactivity (P = 0.007). The CSF-1R antibody showed a positive correlation for local relapse, but no correlation was found between CSF-1R expression and distant metastasis. In summary, our findings provide evidence for the poor prognostic role of CSF-1R in IBTR.