342 research outputs found
HTML Macros -- Easing the Construction and Maintenance of Web Texts
Authoring and maintaining large collections of Web texts is a cumbersome, error-prone and time-consuming business. Ongoing development of courseware for the High Performance Computing Consortium (HPCC) TLTP has only helped to emphasise these problems. Courseware requires the application of a coherent document layout (templates) for each page, and also the use of standard icons with a consistent functionality, in order to create a constant look and feel throughout the material. This provides the user with an environment where he or she can access new pages, and instantly recognise the format used, making the extraction of the information on the page much quicker, and less immediately confusing. This paper describes a system that was developed at UKC to provide a solution to the above problems via the introduction of HTML macros. These macros can be used to provide a standard document layout with a consistent look and feel, as well as tools to ease user navigation. The software is written in Perl, and achieves macro expansion and replacement using the Common Gateway Interface (CGI) and filtering the HTML source. Using macros in your HTML results in your document source code being shorter, more robust, and more powerful. Webs of documents can be built extremely fast and maintenance is made much simpler. Keywords: Authoring, Automation Tools, Perl filters for HTML, Teaching and learning on the We
Evidence for the temporal regulation of insect segmentation by a conserved sequence of transcription factors
Long-germ insects, such as the fruit fly Drosophila melanogaster, pattern their segments simultaneously, whereas short-germ insects, such as the beetle Tribolium castaneum, pattern their segments sequentially, from anterior to posterior. While the two modes of segmentation at first appear quite distinct, much of this difference might simply reflect developmental heterochrony. We now show here that, in both Drosophila and Tribolium, segment patterning occurs within a common framework of sequential Caudal, Dichaete, and Odd-paired expression. In Drosophila these transcription factors are expressed like simple timers within the blastoderm, while in Tribolium they form wavefronts that sweep from anterior to posterior across the germband. In Drosophila, all three are known to regulate pair-rule gene expression and influence the temporal progression of segmentation. We propose that these regulatory roles are conserved in short-germ embryos, and that therefore the changing expression profiles of these genes across insects provide a mechanistic explanation for observed differences in the timing of segmentation. In support of this hypothesis we demonstrate that Odd-paired is essential for segmentation in Tribolium, contrary to previous reports
Digital Histories of Crime and Research-Based Teaching and Learning
The proliferation of digitised primary sources has created exciting possibilities for those of us teaching undergraduate modules on crime and punishment in nineteenth century England and Wales. In this article, we reflect on our experience of devising and running a ‘special subject’ at the University of Liverpool in which we encourage our students to see themselves as active, independent researchers - as producers, rather than passive consumers, of knowledge. Working on individual projects in a group of 15, students tackle the different stages of the research process side-by-side, discussing issues of research design, record-linkage and the interpretation and analysis of primary and secondary sources with each other as well as with members of staff and PhD students. In our experience, this approach leads to very high levels of student engagement. It also provides invaluable, ‘hands-on’ research training for final year undergraduates as they prepare to embark on their dissertations
Recommended from our members
Arthropod segmentation.
There is now compelling evidence that many arthropods pattern their segments using a clock-and-wavefront mechanism, analogous to that operating during vertebrate somitogenesis. In this Review, we discuss how the arthropod segmentation clock generates a repeating sequence of pair-rule gene expression, and how this is converted into a segment-polarity pattern by 'timing factor' wavefronts associated with axial extension. We argue that the gene regulatory network that patterns segments may be relatively conserved, although the timing of segmentation varies widely, and double-segment periodicity appears to have evolved at least twice. Finally, we describe how the repeated evolution of a simultaneous (Drosophila-like) mode of segmentation within holometabolan insects can be explained by heterochronic shifts in timing factor expression plus extensive pre-patterning of the pair-rule genes.BBSRC grant BB/P009336/1 in Cambridge (MA and EC)
BBSRC grant BB/L020092/1 in Leeds (ADP)
Trinity College JRF to Erik Clark in Cambridge
EMBO Long term fellowship to Erik Clark in Harvar
The responses of Tribolium castaneum to wheat germ oil and fungal produced volatiles: Presentation
The red flour beetle Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) is a significant pest affecting a wide variety of different stored products around the Globe. Despite its economic impact, there is evidence that the lures currently used in traps to monitor for this species are largely ineffective. Based on the evolutionary history of T. castaneum, and the ecological niche it occupies, the volatiles of wheat germ oil and volatiles produced by grain-associated fungi have the potential to act as attractants for this species. We used electroantennography (EAG) to measure the electrophysiological response elicited by sixty-eight volatile compounds found in wheat germ oil and/or grain-associated fungi in two T. castaneum strains; an established lab population (CTC12 strain) and a recently caught wild population. Many volatile compounds from both sources elicited strong antennal depolarisations, and the responses of both strains were highly correlated. We then tested whether the compounds that triggered the strongest antennal depolarisations also elicited behavioural responses by using Y-tube olfactometer bioassays and identified several compounds attractive to both strains. The discovery of novel compounds that elicit strong EAG signals and behavioural responses could prove useful in the design of improved lures for T. castaneum and other stored product pests. Our future research will identify how effective these attractive volatiles might be when used in combination, and when used under conditions that more closely replicate a stored product environment.The red flour beetle Tribolium castaneum Herbst (Coleoptera: Tenebrionidae) is a significant pest affecting a wide variety of different stored products around the Globe. Despite its economic impact, there is evidence that the lures currently used in traps to monitor for this species are largely ineffective. Based on the evolutionary history of T. castaneum, and the ecological niche it occupies, the volatiles of wheat germ oil and volatiles produced by grain-associated fungi have the potential to act as attractants for this species. We used electroantennography (EAG) to measure the electrophysiological response elicited by sixty-eight volatile compounds found in wheat germ oil and/or grain-associated fungi in two T. castaneum strains; an established lab population (CTC12 strain) and a recently caught wild population. Many volatile compounds from both sources elicited strong antennal depolarisations, and the responses of both strains were highly correlated. We then tested whether the compounds that triggered the strongest antennal depolarisations also elicited behavioural responses by using Y-tube olfactometer bioassays and identified several compounds attractive to both strains. The discovery of novel compounds that elicit strong EAG signals and behavioural responses could prove useful in the design of improved lures for T. castaneum and other stored product pests. Our future research will identify how effective these attractive volatiles might be when used in combination, and when used under conditions that more closely replicate a stored product environment
Recommended from our members
Group 11 'Ate Bases: Towards an Understanding of Solid- and Solution-State Structures
Lithium bis(amido)cuprates are an important class of bimetallic base, which can
chemo- and regioselectively metalate aromatic compounds, via directed ortho
cupration (DoCu). This thesis begins with an introduction to aspects of the chemistry
of organolithium compounds, group 11 organometallic compounds and their
lithium 'ate complexes. Examples of such synergic bases are presented and the
introduction is concluded with a discussion of lithium bis(amido)cuprate bases,
which along with their silver congeners, are the subject of this dissertation. In
general, syntheses involve the addition of a lithium amide to a group 11 salt,
resulting in the formation of a lithium bis(amido)cuprate or argentate.
Structurally focussed work commences with the use of new amide ligands to develop
heteroleptic bis(amido)cuprate systems. The reaction of mixtures of lithium
amides with CuBr provides a series of novel Lipshutz-type and Gilman cuprates.
Interesting structural features are uncovered, which are rationalised in terms of
altered steric demands in the newly introduced amide ligands in these systems.
CuSCN and CuOCN are investigated as inexpensive and safer alternatives to
CuCN in cuprate formation. In the solid state, a series of Lipshutz-type cuprates
(TMP)2Cu(SCN)Li2(L) (L = Et2O, THF, THP) are revealed, whose molecular
conformations are infuenced by the identity of the Lewis base. However, in benzene
solution, in situ conversion of Lipshutz-type to Gilman cuprate is found to
occur. Moving to the synthetic setting, derivatisation of chloropyridines is attempted
and gives functionalised halopyridines in 51-71 % yield. CuOCN is found
to behave quite differently when reacted in the same way as CuSCN, whereby
X-ray crystallography reveals structures in which Cu-Li substitution is apparent. The unique reactivity of CuOCN is interpreted with the aid of multinuclear NMR
spectroscopy. A new route to Lipshutz-type cuprates is explored by the synthesis
of (TMP)2Cu(OCN)Li2(THF) from Gilman cuprate and LiOCN. This avoids
Cu-Li substitution. Meanwhile, reaction of lithium N,N-diisopropylamide with
CuOCN also avoids metal disorder, to give a novel lithium cuprate-lithium amide
adduct.
Further advances in our understanding of group 11 'ate complexes are made
by introducing silver as a spectroscopically active nucleus in the lithium argentates
(TMP)2AgLi and (TMP)2Ag(CN)Li2(THF). In the solid state, these parallel
the structures known for Gilman cuprate (TMP)2CuLi and Lipshutz cuprate
(TMP)2Cu(CN)Li2(THF), respectively. In solution, NMR spectroscopy reveals
features consistent with retention of these structures. Lastly, the formation of
mixed Cu-Li aggregates from combining TMPLi and TMPCu in aromatic solvent
are investigated. Surprising reactivity is uncovered, in which the aromatic solvent
is metalated and incorporated into mixed-metal aggregates.
This thesis concludes with a summary of the findings and suggestions for future
work, including how the findings presented herein may be transformed into practical
improvements to cuprate systems. In particular, the possibility that Gilman
cuprate may be activated towards the metalation of aromatic substrates by the
addition of sub-stoichiometric or catalytic amounts of a lithium salt additive is
explored.EPSRC grant EP/J500380/
Twin Ice Cores from Greenland Reveal History of Climate Change, More
Two projects conducted from 1989 to 1993 collected parallel ice cores—just 30 km apart— from the central part of the Greenland ice sheet. Each core is more than 3 km deep and extends back 110,000 years. In short, the ice cores tell a clear story: humans came of age agriculturally and industrially during the most stable climatic regime recorded in the cores. Change—large, rapid, and global—is more characteristic of the Earth\u27s climate than is stasis
Preface
This special issue of the Journal of Geophysical Research presents 47 papers developed from research on the two deep ice cores drilled in central Greenland during the years 1989-1993 by the U.S. Greenland Ice Sheet Project 2 (GISP2) and the European Greenland Ice Core Program (GRIP). In this grand experiment, two large ice-core-drilling programs were combined. A major reason was to validate the presence of fast climate oscillations that could not be verified by a single deep ice core
HTML macros - easing the construction and maintenance of web texts
Abstract Authoring and maintaining large collections of Web texts is a cumbersome, error-prone and time-consuming business. Ongoing development of courseware for the High Performance Computing Consortium (HPCC) TLTP 2 has only helped to emphasise these problems. Courseware requires the application of a coherent document layout (templates) for each page, and also the use of standard icons with a consistent functionality, in order to create a constant look and feel throughout the material. This provides the user with an environment where he or she can access new pages, and instantly recognise the format used, making the extraction of the information on the page much quicker, and less immediately confusing. This paper describes a system that was developed at UKC to provide a solution to the above problems via the introduction of HTML macros. These macros can be used to provide a standard document layout with a consistent look and feel, as well as tools to ease user navigation. The software is written in Perl, and achieves macro expansion and replacement using the Common Gateway Interface (CGI) and filtering the HTML source. Using macros in your HTML results in your document source code being shorter, more robust, and more powerful. Webs of documents can be built extremely fast and maintenance is made much simpler
- …