A Guy - Academia.edu (original) (raw)
Papers by A Guy
Proceedings of the 23rd International Conference on World Wide Web, 2014
Current discussions of social machines rightly emphasise a human's role as a crucial part of a sy... more Current discussions of social machines rightly emphasise a human's role as a crucial part of a system rather than a user of a system. The human 'parts' are typically considered in terms of their aggregate outcomes and collective behaviours, but human participants are rarely all equal, even within a small system. We argue that due to the complex nature of online identity, understanding participants in a more granular way is crucial for social machine observation and design. We present the results of a study of the personas portrayed by participants in a social machine that produces creative media content, and discover that inconsistent or misleading representations of individuals do not necessarily undermine the system in which they are participating. We describe a preliminary framework for making sense of human participants in social machines, and the ongoing work that develops this further.
British Polymer Journal, 1985
The effect of a range of organic additives on the thermal stability of poly(vinyl chloride), both... more The effect of a range of organic additives on the thermal stability of poly(vinyl chloride), both with and without a chloroparaffin extender, was studied using a number of experimental techniques. Of the additives used the best overall balance was provided by pentaerythritol, which increased stability when the extender was present and had no effect when it was absent. The congo red test emerged as the most suitable technique, being consistent and inexpensive and able to screen several additives simultaneously. Isothermal differential thermal analysis correlated with the congo red test but required more expensive equipment, was time-consuming and demanded good mixing of the poly(vinyl chloride) compound to give reproducible results. Thermogravimetry was not sufficiently sensitive and the heat stability test was the least useful of all.
Soins. Formation, pédagogie, encadrement : avec la participation du CEEIEC, 1994
British journal of experimental pathology, 1989
The object of this study was to discover new M. tuberculosis antigens which are recognized by pat... more The object of this study was to discover new M. tuberculosis antigens which are recognized by patients with tuberculosis, because effective serodiagnostic tests are likely to require combinations of different antigens. In our early experiments using immunoblotting, the findings suggested that human sera from smear-negative tuberculosis patients bound to an antigen in the 45 kDa region. Subsequently, estimates of molecular weight in the immunoblots confirmed that the murine monoclonal antibody (MAB) HGT-6 and sera from patients both recognized the same 45 kDa molecule. An antibody-antibody competition assay between MAB HGT-6 and sera from smear-positive tuberculosis patients yielded a positive result in 23 out of 43 sera from patients, but in only four out of 23 from controls. This is further evidence that the 45 kDa antigen is recognized by tuberculous patients. We analysed whether a combination of the 45 kDa antigen results and those of known antigens might better discriminate betw...
Tetrahedron: Asymmetry, 2000
The kinetic resolution of 3-nitro-cyclopent(or hex)-2-en-1-yl acetates via enzymatic hydrolysis u... more The kinetic resolution of 3-nitro-cyclopent(or hex)-2-en-1-yl acetates via enzymatic hydrolysis using Pseudomonas cepacia lipase is described. A model, based on a strong interaction between the nitro group and the active site, accounts for the structural selectivity and the stereoselectivity observed.
Thermochimica Acta, 1985
Abstract DTA correlates well with the standard congo red test for the thermal stability of polyvi... more Abstract DTA correlates well with the standard congo red test for the thermal stability of polyvinylchloride (PVC). Thermogravimetry is not sufficiently sensitive and the heat stability test is the least useful of all.
Tetrahedron Letters, 1990
Deoxyribosylurea is an alkali sensitive DNA defect induced by the action of ionizing radiation. O... more Deoxyribosylurea is an alkali sensitive DNA defect induced by the action of ionizing radiation. Oligonucleotides bearing this residue were synthesized using 5'-0-(4-methoxytrityI)-2'-deoxyribo.sylurea-3'-0-(P-cyanoethyl-N,N'-diisopropyl) phosphoramidite and PAC protected deoxynucleoside phosphoramidites.
Tetrahedron Letters, 1980
Resume Fully protected mononucleotides are prepared by the action of parachlorophenylphosphodichl... more Resume Fully protected mononucleotides are prepared by the action of parachlorophenylphosphodichloridite in THF on the corresponding nucleosides followed by oxidation with iodine.
Tetrahedron, 1987
Rdsltme : Nous utilisons des nitrocyclohexadienones co-rdactifs de nitration. Ces produits sent z... more Rdsltme : Nous utilisons des nitrocyclohexadienones co-rdactifs de nitration. Ces produits sent znt accessibles A partir des perhalogdnophdnols correspondants ; ils sont stables et faciles A manipuler. L'blan moteur de la reaction est la rdaromstisation du cycle du rdactif qui conduit A la nitration dans des conditions particulierement deuces. Ces rdactifs permettent la nitration directe et avec de bons rendemsnts de composes t&s activds co-les dihydroxynaphtalenes.
Synthesis, 1991
The proton at C-9 of 3-methoxyestra-1,3,5(10)-trienes 1-4 was replaced by an azido group regio- a... more The proton at C-9 of 3-methoxyestra-1,3,5(10)-trienes 1-4 was replaced by an azido group regio- and stereospecifically in one step by reaction with hydrazoic acid in chloroform in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)
Surface Science, 1985
Abstract The effect of submonolayer and monolayer amounts of Pb deposited at underpotential on a ... more Abstract The effect of submonolayer and monolayer amounts of Pb deposited at underpotential on a polycrystalline Ag electrode surface on the surface enhanced Raman scattering behavior of pyridine and Cl − adsorbates is presented. Surfaces covered by greater than 70% of a Pb monolayer do not support significant surface enhancement. The changes observed in SERS intensity as a function of fractional Pb coverage are interpreted in terms of changes in surface electronic properties and changes in adsorbate coverage. Evidence for changes in the structure of the Pb overlayer is also presented. Investigation of the reversibility of the SERS behavior after deposition and quantitative stripping of varying amounts of Pb provides information on the roles played by various sizes of surface roughness in SERS. These data suggest that both large scale and atomic scale roughness contribute to the SERS intensities measured in these systems.
Separation Science and Technology, 1995
The nuclear fuel reprocessing currently used generates liquid wastes with a significant level of ... more The nuclear fuel reprocessing currently used generates liquid wastes with a significant level of radioactivity that requires expensive and specific treatments. Therefore, in this study, an attempt has been made to develop another process that is more effective and produces less-active wastes by using a poly(4-vinylpyridine) resin as selective material for fixation of metal ions present at trace level, in
Separation Science and Technology, 1997
In aqueous medium, selective complexation increases the ionic separation by nanofiltration. The c... more In aqueous medium, selective complexation increases the ionic separation by nanofiltration. The combination of nanofiltration and complexation can be applied to the nuclear effluents treatment. To separate radioelements from a sodium salt medium, poly(acrylic acid) is associated to the FILMTEC NF 70 membrane. Effects of transmembrane pressure, pH, ligand concentration and ionic strength on salts retention are described, and the
Review of Scientific Instruments, 2002
The combination of cyclotron and electron cyclotron resonance (ECR) ion source provides the abili... more The combination of cyclotron and electron cyclotron resonance (ECR) ion source provides the ability to accelerate ``cocktails'' of ions, mixtures of ions of near-identical charge-to-mass ratio. This concept was developed soon after the first ECR ion source became operational at the 88 Inch Cyclotron and has become a powerful tool in the field of heavy ion radiation effects testing. The
Psychology and Psychotherapy: Theory, Research and Practice, 2003
Using Q-methodology and structured interviews, this preliminary study set out to explore how a di... more Using Q-methodology and structured interviews, this preliminary study set out to explore how a diverse range of voice hearers construed their experience of hearing voices. Following factor analysis of 20 completed Q-sorts, six factors emerged. Pejorative media stereotypes about voice hearers were rejected, and despite the dominance of the biomedical model in our culture, on no factor did participants adhere to all of the biomedical concepts. All six factors endorsed some elements of psychological discourse on voice-hearing experiences. It is argued that attempting to understand voice hearers within a single theoretical framework may limit or adversely affect engagement and understanding of an individual. Consistent with previous research, users of mental-health services were more likely to nd voices frightening and perceive them as negative experiences than non-users. However, some non-users found managing some of their voices dif cult despite having seemingly positive beliefs about the experience of hearing voices. Comment is made on the potential therapeutic implications of this study along with some acknowledgement of its limitations.
Nucleic Acids Research, 1991
We have determined by two-dimensional nuclear magnetic resonance studies and molecular mechanics ... more We have determined by two-dimensional nuclear magnetic resonance studies and molecular mechanics calculations the three-dimensional solution structure of a 21 residue oligonucleotide capable of forming a hairpin structure with a loop of three thymidine residues. This structure is in equilibrium with a duplex form. At 330C, low ionic strength and in the presence of MgCI2 the hairpin form dominates in solution. Six Watson-Crick base pairs are formed topped by the loop structure. The residues 1-3 and 18-21 are not complementary and form dangling ends. Distance constraints have been derived from nuclear Overhauser enhancement measurements. These, together with molecular mechanics calculations, have been used to determine the structure. We do not observe stacking of thymidine residues either over the 3' or the 5' end of the stem.
Nucleic Acids Research, 1993
The structure of d(CGCGm4CG) where m4C = N4methylcytosine has been determined by crystallographic... more The structure of d(CGCGm4CG) where m4C = N4methylcytosine has been determined by crystallographic methods. The crystals are multifaced prisms, with orthorhombic space group P212121 and unit cell dimensions of a = 17.98, b = 30.77 and c = 44.75A. The asymmetric unit consists of one duplex of hexanucleotide and 49 waters. The R-factor is 0.189 for 1495 reflections with F 2 a(F) to a resolution limit of 1.8A. The double helix has a Z-DNA type structure which appears to be intermediate in structure to the two previously characterised structure types for Z-DNA hexamers. The two m4C-G base-pairs adopt structures that are very similar to those of the equivalent basepairs in the structure of the native sequence d(CGCGCG) except for the presence of the methyl groups which are trans to the N3 atoms of their parent nucleotides and protrude into the solvent region. The introduction of the modified base-pairs into the d(CGCGCG) duplex appears to have a minimal effect on the overall base-pair morphology of the Z-DNA duplex.
Journal of Radioanalytical and Nuclear Chemistry Letters, 1994
Journal of Natural Resources and Life Sciences Education, 2010
A field-based, soil methods, and instrumentation course was developed to expose graduate students... more A field-based, soil methods, and instrumentation course was developed to expose graduate students to numerous strategies for measuring soil parameters. Given the northern latitude of North Dakota State University and the rapid onset of winter, this course met once per week for the first 8 weeks of the fall semester and centered on the field as a classroom, allowing the students to learn through hands-on participation. The major focus of the course was providing a real-life example where the scientific method was used to answer a testable hypothesis. Students developed testable hypotheses, designed an experiment, determined sampling protocol and sample analysis, conducted statistical analysis, and wrote results in a peer-reviewed format. The research question for this course was, "What is the concentration of total mercury (Hg) in roadside soils of North Dakota?" The results from the student project indicated that total soil Hg concentration increased with increasing distance from the roadside shoulder and that total soil Hg concentration was not statistically different between high-traffic and low-traffic areas. Field-based courses and student-driven research projects are excellent ways to introduce research methods to graduate students. Student learning was enhanced during the experiential learning process by allowing the students to follow the scientific method starting from the formulation of ideas (research question and testable hypotheses) to the preparation of a manuscript.
Proceedings of the 23rd International Conference on World Wide Web, 2014
Current discussions of social machines rightly emphasise a human's role as a crucial part of a sy... more Current discussions of social machines rightly emphasise a human's role as a crucial part of a system rather than a user of a system. The human 'parts' are typically considered in terms of their aggregate outcomes and collective behaviours, but human participants are rarely all equal, even within a small system. We argue that due to the complex nature of online identity, understanding participants in a more granular way is crucial for social machine observation and design. We present the results of a study of the personas portrayed by participants in a social machine that produces creative media content, and discover that inconsistent or misleading representations of individuals do not necessarily undermine the system in which they are participating. We describe a preliminary framework for making sense of human participants in social machines, and the ongoing work that develops this further.
British Polymer Journal, 1985
The effect of a range of organic additives on the thermal stability of poly(vinyl chloride), both... more The effect of a range of organic additives on the thermal stability of poly(vinyl chloride), both with and without a chloroparaffin extender, was studied using a number of experimental techniques. Of the additives used the best overall balance was provided by pentaerythritol, which increased stability when the extender was present and had no effect when it was absent. The congo red test emerged as the most suitable technique, being consistent and inexpensive and able to screen several additives simultaneously. Isothermal differential thermal analysis correlated with the congo red test but required more expensive equipment, was time-consuming and demanded good mixing of the poly(vinyl chloride) compound to give reproducible results. Thermogravimetry was not sufficiently sensitive and the heat stability test was the least useful of all.
Soins. Formation, pédagogie, encadrement : avec la participation du CEEIEC, 1994
British journal of experimental pathology, 1989
The object of this study was to discover new M. tuberculosis antigens which are recognized by pat... more The object of this study was to discover new M. tuberculosis antigens which are recognized by patients with tuberculosis, because effective serodiagnostic tests are likely to require combinations of different antigens. In our early experiments using immunoblotting, the findings suggested that human sera from smear-negative tuberculosis patients bound to an antigen in the 45 kDa region. Subsequently, estimates of molecular weight in the immunoblots confirmed that the murine monoclonal antibody (MAB) HGT-6 and sera from patients both recognized the same 45 kDa molecule. An antibody-antibody competition assay between MAB HGT-6 and sera from smear-positive tuberculosis patients yielded a positive result in 23 out of 43 sera from patients, but in only four out of 23 from controls. This is further evidence that the 45 kDa antigen is recognized by tuberculous patients. We analysed whether a combination of the 45 kDa antigen results and those of known antigens might better discriminate betw...
Tetrahedron: Asymmetry, 2000
The kinetic resolution of 3-nitro-cyclopent(or hex)-2-en-1-yl acetates via enzymatic hydrolysis u... more The kinetic resolution of 3-nitro-cyclopent(or hex)-2-en-1-yl acetates via enzymatic hydrolysis using Pseudomonas cepacia lipase is described. A model, based on a strong interaction between the nitro group and the active site, accounts for the structural selectivity and the stereoselectivity observed.
Thermochimica Acta, 1985
Abstract DTA correlates well with the standard congo red test for the thermal stability of polyvi... more Abstract DTA correlates well with the standard congo red test for the thermal stability of polyvinylchloride (PVC). Thermogravimetry is not sufficiently sensitive and the heat stability test is the least useful of all.
Tetrahedron Letters, 1990
Deoxyribosylurea is an alkali sensitive DNA defect induced by the action of ionizing radiation. O... more Deoxyribosylurea is an alkali sensitive DNA defect induced by the action of ionizing radiation. Oligonucleotides bearing this residue were synthesized using 5'-0-(4-methoxytrityI)-2'-deoxyribo.sylurea-3'-0-(P-cyanoethyl-N,N'-diisopropyl) phosphoramidite and PAC protected deoxynucleoside phosphoramidites.
Tetrahedron Letters, 1980
Resume Fully protected mononucleotides are prepared by the action of parachlorophenylphosphodichl... more Resume Fully protected mononucleotides are prepared by the action of parachlorophenylphosphodichloridite in THF on the corresponding nucleosides followed by oxidation with iodine.
Tetrahedron, 1987
Rdsltme : Nous utilisons des nitrocyclohexadienones co-rdactifs de nitration. Ces produits sent z... more Rdsltme : Nous utilisons des nitrocyclohexadienones co-rdactifs de nitration. Ces produits sent znt accessibles A partir des perhalogdnophdnols correspondants ; ils sont stables et faciles A manipuler. L'blan moteur de la reaction est la rdaromstisation du cycle du rdactif qui conduit A la nitration dans des conditions particulierement deuces. Ces rdactifs permettent la nitration directe et avec de bons rendemsnts de composes t&s activds co-les dihydroxynaphtalenes.
Synthesis, 1991
The proton at C-9 of 3-methoxyestra-1,3,5(10)-trienes 1-4 was replaced by an azido group regio- a... more The proton at C-9 of 3-methoxyestra-1,3,5(10)-trienes 1-4 was replaced by an azido group regio- and stereospecifically in one step by reaction with hydrazoic acid in chloroform in the presence of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)
Surface Science, 1985
Abstract The effect of submonolayer and monolayer amounts of Pb deposited at underpotential on a ... more Abstract The effect of submonolayer and monolayer amounts of Pb deposited at underpotential on a polycrystalline Ag electrode surface on the surface enhanced Raman scattering behavior of pyridine and Cl − adsorbates is presented. Surfaces covered by greater than 70% of a Pb monolayer do not support significant surface enhancement. The changes observed in SERS intensity as a function of fractional Pb coverage are interpreted in terms of changes in surface electronic properties and changes in adsorbate coverage. Evidence for changes in the structure of the Pb overlayer is also presented. Investigation of the reversibility of the SERS behavior after deposition and quantitative stripping of varying amounts of Pb provides information on the roles played by various sizes of surface roughness in SERS. These data suggest that both large scale and atomic scale roughness contribute to the SERS intensities measured in these systems.
Separation Science and Technology, 1995
The nuclear fuel reprocessing currently used generates liquid wastes with a significant level of ... more The nuclear fuel reprocessing currently used generates liquid wastes with a significant level of radioactivity that requires expensive and specific treatments. Therefore, in this study, an attempt has been made to develop another process that is more effective and produces less-active wastes by using a poly(4-vinylpyridine) resin as selective material for fixation of metal ions present at trace level, in
Separation Science and Technology, 1997
In aqueous medium, selective complexation increases the ionic separation by nanofiltration. The c... more In aqueous medium, selective complexation increases the ionic separation by nanofiltration. The combination of nanofiltration and complexation can be applied to the nuclear effluents treatment. To separate radioelements from a sodium salt medium, poly(acrylic acid) is associated to the FILMTEC NF 70 membrane. Effects of transmembrane pressure, pH, ligand concentration and ionic strength on salts retention are described, and the
Review of Scientific Instruments, 2002
The combination of cyclotron and electron cyclotron resonance (ECR) ion source provides the abili... more The combination of cyclotron and electron cyclotron resonance (ECR) ion source provides the ability to accelerate ``cocktails'' of ions, mixtures of ions of near-identical charge-to-mass ratio. This concept was developed soon after the first ECR ion source became operational at the 88 Inch Cyclotron and has become a powerful tool in the field of heavy ion radiation effects testing. The
Psychology and Psychotherapy: Theory, Research and Practice, 2003
Using Q-methodology and structured interviews, this preliminary study set out to explore how a di... more Using Q-methodology and structured interviews, this preliminary study set out to explore how a diverse range of voice hearers construed their experience of hearing voices. Following factor analysis of 20 completed Q-sorts, six factors emerged. Pejorative media stereotypes about voice hearers were rejected, and despite the dominance of the biomedical model in our culture, on no factor did participants adhere to all of the biomedical concepts. All six factors endorsed some elements of psychological discourse on voice-hearing experiences. It is argued that attempting to understand voice hearers within a single theoretical framework may limit or adversely affect engagement and understanding of an individual. Consistent with previous research, users of mental-health services were more likely to nd voices frightening and perceive them as negative experiences than non-users. However, some non-users found managing some of their voices dif cult despite having seemingly positive beliefs about the experience of hearing voices. Comment is made on the potential therapeutic implications of this study along with some acknowledgement of its limitations.
Nucleic Acids Research, 1991
We have determined by two-dimensional nuclear magnetic resonance studies and molecular mechanics ... more We have determined by two-dimensional nuclear magnetic resonance studies and molecular mechanics calculations the three-dimensional solution structure of a 21 residue oligonucleotide capable of forming a hairpin structure with a loop of three thymidine residues. This structure is in equilibrium with a duplex form. At 330C, low ionic strength and in the presence of MgCI2 the hairpin form dominates in solution. Six Watson-Crick base pairs are formed topped by the loop structure. The residues 1-3 and 18-21 are not complementary and form dangling ends. Distance constraints have been derived from nuclear Overhauser enhancement measurements. These, together with molecular mechanics calculations, have been used to determine the structure. We do not observe stacking of thymidine residues either over the 3' or the 5' end of the stem.
Nucleic Acids Research, 1993
The structure of d(CGCGm4CG) where m4C = N4methylcytosine has been determined by crystallographic... more The structure of d(CGCGm4CG) where m4C = N4methylcytosine has been determined by crystallographic methods. The crystals are multifaced prisms, with orthorhombic space group P212121 and unit cell dimensions of a = 17.98, b = 30.77 and c = 44.75A. The asymmetric unit consists of one duplex of hexanucleotide and 49 waters. The R-factor is 0.189 for 1495 reflections with F 2 a(F) to a resolution limit of 1.8A. The double helix has a Z-DNA type structure which appears to be intermediate in structure to the two previously characterised structure types for Z-DNA hexamers. The two m4C-G base-pairs adopt structures that are very similar to those of the equivalent basepairs in the structure of the native sequence d(CGCGCG) except for the presence of the methyl groups which are trans to the N3 atoms of their parent nucleotides and protrude into the solvent region. The introduction of the modified base-pairs into the d(CGCGCG) duplex appears to have a minimal effect on the overall base-pair morphology of the Z-DNA duplex.
Journal of Radioanalytical and Nuclear Chemistry Letters, 1994
Journal of Natural Resources and Life Sciences Education, 2010
A field-based, soil methods, and instrumentation course was developed to expose graduate students... more A field-based, soil methods, and instrumentation course was developed to expose graduate students to numerous strategies for measuring soil parameters. Given the northern latitude of North Dakota State University and the rapid onset of winter, this course met once per week for the first 8 weeks of the fall semester and centered on the field as a classroom, allowing the students to learn through hands-on participation. The major focus of the course was providing a real-life example where the scientific method was used to answer a testable hypothesis. Students developed testable hypotheses, designed an experiment, determined sampling protocol and sample analysis, conducted statistical analysis, and wrote results in a peer-reviewed format. The research question for this course was, "What is the concentration of total mercury (Hg) in roadside soils of North Dakota?" The results from the student project indicated that total soil Hg concentration increased with increasing distance from the roadside shoulder and that total soil Hg concentration was not statistically different between high-traffic and low-traffic areas. Field-based courses and student-driven research projects are excellent ways to introduce research methods to graduate students. Student learning was enhanced during the experiential learning process by allowing the students to follow the scientific method starting from the formulation of ideas (research question and testable hypotheses) to the preparation of a manuscript.