Researchers on the pier: Academics’ use of a local internet gateway

This paper describes the establishment of an Internet gateway local to the University of Sussex, firstly as a Gopher and more recently as a World Wide Web server. There follows an account of a project currently underway to assess the practical value of Internet resources to research and the consequential training and support requirements. This assessment is planned to determine the value of a local gateway to academic researchers at Sussex and the roles specific to a local gateway that such comprehensive resources as Yahoo and BUBL cannot fulfil. The project is using an interview‐based methodology to gain an understanding of researchers’ views of Internet resource provision, and these interviews are being analysed with the help of the NUD*IST qualitative data analysis software package. The account is of research in progress, and hence does not conclude with the set of pragmatic policy proposals that forms its key objective. Instead, some indication is given of the broad early findings of the project     

Implementation intentions, occupational stress, and the exercise intention-behavior relationship.

Many individuals intend to exercise, but fail to link this intention to behavior. The present study examined the impact of an implementation intention intervention (i.e., instructions to form specific if-then plans) on an exercise intention-behavior relationship among working adults who varied in reported occupational stress levels. Results indicated that implementation intentions backfired, such that participants who did not form an implementation intention exercised significantly more than participants who formed an implementation intention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do citations and impact factors relate to the real numbers in publications? A case study of citation rates, impact, and effect sizes in ecology and evolutionary biology

Metrics of success or impact in academia may do more harm than good. To explore the value of citations, the reported efficacy of treatments in ecology and evolution from close to 1,500 publications was examined. If citation behavior is rationale, i.e. studies that successfully applied a treatment and detected greater biological effects are cited more frequently, then we predict that larger effect sizes increases study relative citation rates. This prediction was not supported. Citations are likely thus a poor proxy for the quantitative merit of a given treatment in ecology and evolutionary biology—unlike evidence-based medicine wherein the success of a drug or treatment on human health is one of the critical attributes. Impact factor of the journal is a broader metric, as one would expect, but it also unrelated to the mean effect sizes for the respective populations of publications. The interpretation by the authors of the treatment effects within each study differed depending on whether the hypothesis was supported or rejected. Significantly larger effect sizes were associated with rejection of a hypothesis. This suggests that only the most rigorous studies reporting negative results are published or that authors set a higher burden of proof in rejecting a hypothesis. The former is likely true to a major extent since only 29 % of the studies rejected the hypotheses tested. These findings indicate that the use of citations to identify important papers in this specific discipline—at least in terms of designing a new experiment or contrasting treatments—is of limited value.     

Reference Stress Approximations for J and COD of Circumferential Through-Wall Cracked Pipes

Reference stress approximations for the J integral and crack tip opening displacement (COD) for circumferential through-wall cracked pipes under tension and under bending are reported. The proposed J estimation equation is fully compatible with the existing reference stress based J estimation, currently embedded in the R6 assessment procedure, but involves a slightly different definition of the reference stress, using an optimised reference load instead of the limit load. This modification enhances the accuracy of the J estimation for circumferentially cracked pipes. Confidence in the proposed equation is gained from the significantly reduced hardening dependence of the plastic influence functions in the GE/EPRI method. The proposed COD estimation equation includes two further modifications. One is the use of a power-law fit to the plastic portion of the stress strain data, instead of the use of the actual stress strain data. In this context, a robust estimation equation for the strain hardening index is given. The other modification is to the plasticity correction term in contained yielding. A lower bound COD estimation equation is also given, similar to the R6 option 1 Jestimation curve, which is suitable when only limited tensile properties are available. The resulting estimation equations are simple to use. Comparisons with experimental pipe test data show that the proposed COD estimation equations provide overall good agreement, which gives confidence in applying them to Leak-before-Break (LBB) analyses.     

A DUCTILE FRACTURE MODEL IN MIXED MODES 1 AND 2

Abstract— Fracture due to crack growth under mixed Modes 1 and 2 loading is considered. The cracking mechanism addressed is that of microvoid growth and linkage under small-scale-yielding conditions. Stress analyses are described which take into account the blunting of the crack tip as the load increases. A damage function is defined, and is evaluated in the intensely-straining region near the blunted notch tip. As the load increases, the size of this damaged region increases until a critical level of damage has been reached over a material-dependent length scale and fracture ensues. The local fracture criterion is then related to the applied loads. The predictions of the model are tested against experiments under Mode 1 loading and also against some mixed Modes 1 and 2 data on a range of materials. The results of the model are conservative and reproduce the experimentally observed Mode 1 failures, in terms of AT, at fracture, to within 25%. In the case of mixed mode loading the model conservatively predicts the fracture load for most of the data.     

The Role of Altered Nucleotide Excision Repair and UVB-Induced DNA Damage in Melanomagenesis

UVB radiation is the most mutagenic component of the UV spectrum that reaches the earth’s surface and causes the development of DNA damage in the form of cyclobutane pyrimidine dimers and 6-4 photoproducts. UV radiation usually results in cellular death, but if left unchecked, it can affect DNA integrity, cell and tissue homeostasis and cause mutations in oncogenes and tumour-suppressor genes. These mutations, if unrepaired, can lead to abnormal cell growth, increasing the risk of cancer development. Epidemiological data strongly associates UV exposure as a major factor in melanoma development, but the exact biological mechanisms involved in this process are yet to be fully elucidated. The nucleotide excision repair (NER) pathway is responsible for the repair of UV-induced lesions. Patients with the genetic disorder Xeroderma Pigmentosum have a mutation in one of eight NER genes associated with the XP complementation groups XP-A to XP-G and XP variant (XP-V). XP is characterized by diminished repair capacity, as well as a 1000-fold increase in the incidence of skin cancers, including melanoma. This has suggested a significant role for NER in melanoma development as a result of UVB exposure. This review discusses the current research surrounding UVB radiation and NER capacity and how further investigation of NER could elucidate the role of NER in avoiding UV-induced cellular death resulting in melanomagenesis.     

The natural history of ocular onchocerciasis over a period of 14--15 years and the effect on this of a single course of suramin therapy

In 1959 a population of 638 persons over the age of seven years, suffering from heavy endemic onchocerciasis in the Sudan-Savannah of West Africa was examined, and approximately half were allotted to a group for treatment with suramin (up to a total of 4-2 g for healthy adults). In 1973 and 1974 it was possible to re-examine 145 persons allotted to the treatment group and 118 persons allotted to the control group. Measurements were made of the incidence of new "eye lesions", the progress of pre-existing "eye-lesions" and the deterioration in visual acuity. These were greater in men than in women, and increased with age. They were also greater in persons who in 1959 had microfilariae in the anterior chamber, and particularly in those who had already developed "eye lesions". Severe reactions occurred in a significant proportion of patients who received suramin, and one died. However, these was less deterioration in the eyes of persons in the treated than in the control group.     

The R6 procedure: recent developments and comparison with alternative approaches

The R6 defect assessment procedure has been continually developed since 1976. It is currently at Revision 3 and a major new release, Revision 4, is planned for 2000. Recent developments in R6 include the incorporation of new appendices on crack arrest methods, weld mismatch effects, local approach and finite element methods. These additions to R6 and other recent developments are briefly described in this paper. The overall aim has been to provide additional advice, which can reduce conservatism in the basic procedure, to increase validation, and to maintain R6 up-to-date with progress in fracture mechanics. R6 has had a major influence on the development of other codes and standards, including the new BS guide BS7910:1999 and the SINTAP procedure. The relationship between these other approaches and R6 is discussed. The paper concludes with a brief outline of the intended framework of R6 Revision 4.     

Ductile tearing simulation of Battelle pipe test using simplified stress‐modified fracture strain concept

In this paper, numerical ductile tearing simulation results are compared with six circumferential through‐wall and surface cracked pipes made of two materials (SA‐333 Gr. 6 and A106 Gr. B carbon steels), performed at Battelle. For simulation, a model using a simplified fracture strain model is employed, by analysing tensile data of the material. By comparing experimental J‐R data with FE simulation results, the damage model dependent on the element size is determined based on the ductility exhaustion concept. The model is used to simulate ductile tearing behaviour of six circumferential through‐wall and surface cracked pipes. In all cases, simulated results agree well with experimental load, crack length and crack mouth opening displacement versus load line displacement data.