Eddy Herman - Academia.edu (original) (raw)

Papers by Eddy Herman

Plastic and Reconstructive Surgery, 1990

... PDF Only. Upper Abdominal Wall Defects: Immediate or Staged Reconstruction? Gottlieb, Jourdan... more ... PDF Only. Upper Abdominal Wall Defects: Immediate or Staged Reconstruction? Gottlieb, Jourdan RMD; Engrav, Loren HMD; Walkinshaw, Marcus DMD; Eddy, A. Craig MD; Herman, Clifford MMD. Collapse Box Abstract. One ...

The impact of 60 MeV proton irradiation on the static device parameters of CMOS transistors fabri... more The impact of 60 MeV proton irradiation on the static device parameters of CMOS transistors fabricated in a 0.18 μm technology is reported and studied as a function of the polysilicon gate length Lpoly. In addition, the role of the gate dielectric in the radiation response of the threshold voltage, the transconductance, the subthreshold swing, the series resistance and the gate-induced drain leakage (GIDL) current is investigated. For certain parameters, an anomalous length dependence has been observed. Furthermore, a stronger degradation is found for the transistors with an NO-annealed gate dielectric compared with a standard thermal gate oxide. Combining the charge separation technique with the GIDL current, additional insight in the damage mechanisms is gained. It is shown that there is evidence for electron trapping close to the drain in the case of the NO devices.

International Journal of Antimicrobial Agents, 2007

Objective: Characterise optochin-resistant strains of Streptococcus pneumoniae associated with pn... more Objective: Characterise optochin-resistant strains of Streptococcus pneumoniae associated with pneumococcal infections in Portugal. Methods: All strains submitted to our laboratory during 1999-2003 were optochin susceptible. Since then, 2 isolates (0.3%) in 2004 and 30 isolates (3.2%) in 2005, recovered from 10 geographically dispersed hospitals, were optochin-resistant. These 32 optochin-resistant S. pneumoniae strains consisted of mixed populations of optochinsusceptible and optochin-resistant isolates. For each isolate, both optochin-resistant and susceptible subpopulations were characterised using a combination of bile solubility, antimicrobial susceptibility, serotyping and macrorestriction profiling, using SmaI and pulsed field gel electrophoresis (PFGE). The BioNumerics software was used to make UPMGA (unweighed pair group method with arithmetic mean) dendrograms of PFGE patterns. The Dice similarity coefficient was used with optimisation and position tolerance settings of 1.0 and 1.5%, respectively. Results: Subculture of individual colonies of each strain exposed a uniformly optochin-resistant subpopulation and a uniformly optochinsusceptible subpopulation. The optochin-resistant subpopulations were bile soluble and reacted with sera targeting pneumococcal capsular polysaccharides, confirming their identification as S. pneumoniae. The antimicrobial susceptibility profile and serotype was identical in both optochin-susceptible and resistant subpopulations suggesting that they corresponded to variants of the same clone. PFGE analysis of each subpopulations revealed indistinguishable PFGE profiles, further supporting the suggestion that these constitute two variants of the same strain. The 32 strains included in this study presented 19 different serotypes, all previously found among invasive and colonisation pneumococcal strains in Portugal. Furthermore, the diversity of PFGE profiles observed and the identification of internationally disseminated clones (ex: clone England14−9) excludes a clonal origin for these strains. Conclusion: Accurate identification of S. pneumoniae isolates is essential for the correct diagnosis and adequate therapy of patients with pneumococcal infections. In view of the findings described here we recommend that at least the bile solubility test should be routinely performed in cases of suspected pneumococcal ethiology, even if the isolates are optochin-resistant, to exclude the possibility of S. pneumoniae.

Postharvest Biology and Technology, 1996

Modified-atmosphere packaging (MAP) and subsequent storage at refrigeration temperature has been ... more Modified-atmosphere packaging (MAP) and subsequent storage at refrigeration temperature has been developed over the last decade as an adequate technique to prolong high quality shelf-life of minimally processed vegetables. The MAP system employed should be carefully tailored to the physiological and microbiological characteristics of the product in order to achieve good quality, safe products. In the current investigation, controlled atmosphere conditions were employed that mimicked the packaging of fresh cut chicory endive under modified atmospheres in order to establish the microbiological characteristics. It was found that the modified-atmosphere conditions that were favourable for product quality, retarded growth of spoilage micro-organisms during storage at low temperature. Growth of the psychrotrophic pathogen Listeria monocytogenes, inoculated on the product, was not inhibited. The extent to which the pathogen grew depended on its initial number, type of chicory endive and size of the population of competitive spoilage microflora. Reducing the initial microbial load by disinfection could minimize microbial spoilage and improve the safety status of the product. However, L. monocytogenes grew better on disinfected produce than on non-disinfected or water-rinsed produce, indicating the practical importance of avoiding recontamination after disinfection.

Boundary-layer Meteorology, 2006

Mossbauer spectroscopy is a nuclear gamma resonance technique particularly well suited to the stu... more Mossbauer spectroscopy is a nuclear gamma resonance technique particularly well suited to the study of materials that contain iron (Fe-57). It can provide information on the oxidation state of iron as well as the type and proportion of iron-containing mineral species in a sample of interest. Iron Mossbauer spectroscopy (FeMS) has been applied to samples believed to have come from Mars (SNC meteorites) and has been helpful in refining the choice among putative Martian surface materials by suggesting a likely nanophase component of the Martian regolity. FeMS spectrum of a Martial analogue material (Hawaiian palagonite) is shown; it is dominated by ferric-bearing phases and shows evidence of a nanophase component. FeMS has also been applied to lunar materials. It can be used to measure the maturity of lunar surface material and has been proposed as a prospector for lunar ilmenite, an oxygen resource mineral. Several years ago we suggested a backscatter Mossbauer spectrometer (BaMS) for a Mars rover mission. Backscatter design was selected as most appropriate for in-situ application because no sample preparation is required. Since that time, we have continued to develop the BaMS instrument in anticipation that it would eventually find a home on a NASA planetary mission. Gooding proposed BaMS as a geochemistry instrument on MESUR. More recently, an LPI workshop has recommended that BaMS be included in a three-instrument payload on the next (1996?) lunar lander.

Journal of Neurochemistry, 2002

Abstract : The presence of a nucleotide pyrophosphatase (EC 3.6.1.9) on the plasma membrane of ra... more Abstract : The presence of a nucleotide pyrophosphatase (EC 3.6.1.9) on the plasma membrane of rat C6 glioma has been demonstrated by analysis of the hydrolysis of ATP labeled in the base and in the α-and γ-phosphates. The enzyme degraded ATP into AMP and PPi and, depending on the ATP concentration, accounted for ~50-75% of the extracellular degradation of ATP. The association of the enzyme with the plasma membrane was confirmed by ATP hydrolysis in the presence of a varying concentration of pyridoxal phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS), a membrane-impermeable inhibitor of the enzyme. PPADS concentration above 20 μM abolished the degradation of ATP into AMP and PPi. The nucleotide pyrophosphatase has an alkaline pH optimum and a Km for ATP of 17 ± 5 μM. The enzyme has a broad substrate specificity and hydrolyzes nucleoside triphosphates, nucleoside diphosphates, dinucleoside polyphosphates, and nucleoside monophosphate esters but is inhibited by nucleoside monophosphates, adenosine 3′,5′-bisphosphate, and PPADS. The substrate specificity characterizes the enzyme as a nucleotide pyrophosphatase/phosphodiesterase I (PD-I). Immunoblotting and autoadenylylation identified the enzyme as a plasma cell differentiation antigen-related protein. Hydrolysis of ATP terminates the autophosphorylation of a nucleoside diphosphate kinase (NDPK/nm23) detected in the conditioned medium of C6 cultures. A function of the pyrophosphatase/PD-I and NDPK in the purinergic and pyrimidinergic signal transduction in C6 is discussed.

We have designed and successfully tested a prototype of a backscatter Moessbauer spectrometer (Ba... more We have designed and successfully tested a prototype of a backscatter Moessbauer spectrometer (BaMS) targeted for use on the Martian surface to (1) determine oxidation states of iron, and (2) identify and determine relative abundances of iron-bearing mineralogies. No sample preparation is required to perform measurements; it is only necessary to bring sample and instrument into physical contact. The prototype meets our projected specification for a flight instrument in terms of mass, power, and volume. A Moessbauer spectrometer on the Martian surface would provide wide variety of information about the current state of the Martian surface, and this information is described.

Cellular Signalling, 2006

Previously it was shown that stimulation of the P2Y 12 receptor activates PKB signalling in C6 gl... more Previously it was shown that stimulation of the P2Y 12 receptor activates PKB signalling in C6 glioma cells [K. Van Kolen and H. Slegers, J. Neurochem. 89, 442.]. In the present study, the mechanisms involved in this response were further elucidated. In cells transfected with the Gβγscavenger β-ARK1/GRK2 or Rap1GAPII, stimulation with 2MeSADP failed to enhance PKB phosphorylation demonstrating that the signalling proceeds through Gβγ-subunits and Rap1. Moreover, Rap1-GTP pull-down assays revealed that P2Y 12 receptor stimulation induced a rapid activation of Rap1. Treatment of cells with the Ca 2+ chelator BAPTA-AM and inhibition of Src and PLD2 with PP2 or 1-butanol, respectively, abrogated P2Y 12 receptor-mediated activation of Rap1 and PKB. In addition inhibition of PKCζ decreased basal and 2MeSADP-stimulated phosphorylation of PKB indicating a role for this PKC isoform in PKB signalling. Although the increased PKB phosphorylation was abolished in the presence of the IGF-I receptor tyrosine kinase inhibitor AG 1024, 2MeSADP did not significantly increase receptor phosphorylation. Nevertheless, phosphorylation of a 120 kDa IGF-I receptor-associated protein was observed. The latter protein was identified by MALDI-TOF/ TOF-MS as the proline-rich tyrosine kinase 2 (Pyk2) that co-operates with Src in a PLD2-dependent manner. Consistent with the signalling towards Rap1 and PKB, activation of Pyk2 was abrogated by Ca 2+ chelation, inhibition of PLD2 and IGF-I receptor tyrosine kinase activity. In conclusion, the data reveal a novel type of cross-talk between P2Y 12 and IGF-I receptors that proceeds through Gβγ-, Ca 2+ -and PLD2-dependent activation of the Pyk2/Src pathway resulting in GTP-loading of Rap1 required for an increased PKB phosphorylation. signal-regulated kinase; IGFR, insulin-like growth factor-I receptor; MALDI-TOF/TOF-MS, matrix-assisted laser desorption-time of flight/time of flight-mass spectrometry; 2MeSADP, 2-methylthioadenosine-5′-diphosphate; MRS 2395, 2-

Journal of Geophysical Research, 2010

1] The flow in the Mozambique Channel is dominated by large, southward propagating, anti-cyclonic... more 1] The flow in the Mozambique Channel is dominated by large, southward propagating, anti-cyclonic eddies, as opposed to a steady western boundary current. These Mozambique Channel eddies feed their waters into the Agulhas Current system, where they are thought to have a significant influence on the formation of the Natal Pulse and Agulhas Ring shedding. Here we use in situ hydrographic and nutrient data, together with satellite altimetry and surface velocity profilers to provide a detailed characterization of the Mozambique Channel eddies. Two warm eddies in the Channel at 20°S and 24°S had diameters of over 200 km. They rotated anti-cyclonically with a tangential velocity of over 0.5 m.s −1 . Vertical sections show that the eddies reached to the bottom of the water column. Relative to the surrounding waters, the features were warm and saline. The total heat and salt anomalies for the southernmost eddy were computed relative to a reference station close by. At 24°S the total anomalies were 1.3 × 10 20 J and 6.9 × 10 12 kg, respectively, being on par with Agulhas rings. Mozambique Channel eddies thus have the potential to form a major contribution to the southward eddy heat flux in the Agulhas Current system. The feature also had positive nutrient and negative oxygen anomalies. The large magnitude of the water mass anomalies within the eddy suggests that interannual variability in Mozambique Channel eddy numbers would have a significant impact on downstream water mass characteristics.

Rapid Communications in Mass Spectrometry, 2002

A liquid chromatography/mass spectrometry (LC/MS) method for the analysis of complex mixtures of ... more A liquid chromatography/mass spectrometry (LC/MS) method for the analysis of complex mixtures of nucleoside mono-, di- and triphosphates has been developed. A short capillary column (35mm × 0.3mm i.d.) was operated under ion-pair high-performance liquid chromatography conditions and hyphenated to (negative) electrospray (tandem) mass spectrometry. As such, the separation of 12 nucleotides was performed by a binary gradient elution using CH3OH/H2O and N,N-dimethylhexylamine (N,N-DMHA) as ion-pairing agent. The influence of different N,N-DMHA concentrations on the chromatographic and mass spectrometric performance was evaluated to achieve optimal LC/MS conditions. In addition it was demonstrated that a controlled admission of ammonium dihydrogen phosphate (NH4H2PO4) improved both chromatographic performance and mass spectrometric detection. Because the system was hyphenated to an orthogonal designed electrospray interface (Z-spray™), long acquisition times were possible without loss of sensitivity. Copyright © 2002 John Wiley & Sons, Ltd.

Deep-sea Research Part Ii-topical Studies in Oceanography, 2003

Between 1995 and 2000, on average 4 eddies per year are observed from satellite altimetry to prop... more Between 1995 and 2000, on average 4 eddies per year are observed from satellite altimetry to propagate southward through the Mozambique Channel, into the upstream Agulhas region. Further south, these eddies have been found to control the timing and frequency of Agulhas ring shedding.

European Journal of Social Psychology, 1999

Abstract In line with a social-support-for-shared-self-interest interpretation of competitive int... more Abstract In line with a social-support-for-shared-self-interest interpretation of competitive intergroup behavior Schopler, Insko, Graetz, Drigotas, Smith and Dahl (1993) observed that, in the face of consistent cooperative outgroup behavior, two ingroup members behaved ...

Journal of Moral Education, 2012

This is a study of teachers’ modelling of civic virtues in the classroom. It focusses on three vi... more This is a study of teachers’ modelling of civic virtues in the classroom. It focusses on three virtues of good citizenship: justice, tolerance and solidarity. The aim is to explore the extent to which teachers can be regarded as models of these virtues. Questionnaires were developed for both students and teachers. Factor analyses showed that the three virtues could be empirically distinguished in teachers’ behaviour. The students rated their teachers higher on the justice and solidarity scales than on the tolerance scale. The teachers rated themselves as less just, but more tolerant than they were rated by their students. Furthermore, the correspondence between students’ perceptions and teachers’ self-ratings was not high: correlations were only found between ratings of teachers’ level of justice. The results of the study indicate that teachers need to become more aware of their exemplary function and the way they are perceived by their students.

Biochemical Pharmacology, 2004

Cyclic AMP-dependent differentiation of rat C6 glioma cells into an astrocyte type II is characte... more Cyclic AMP-dependent differentiation of rat C6 glioma cells into an astrocyte type II is characterized by inhibition of cell growth and induction of glial fibrillary acidic protein (GFAP) synthesis. Activation of the P2Y 12 receptor with 2-methylthioadenosine-5 0 -diphosphate inhibited b-adrenergic receptor-induced differentiation. The selective P2Y 12 receptor antagonist N 6 -(2-methylthioethyl)-2-(3,3,3trifluoropropylthio)-b,g-dichloromethylene ATP abolished the receptor-mediated effect on differentiation. In contrast non-selective antagonists of P2Y receptors did not revert the inhibiting effect of the P2Y 12 receptor on differentiation. Reactive blue 2 (RB2), a potent P2Y 12 receptor antagonist, completely inhibited the synthesis of GFAP, while the P2Y receptor antagonists suramin and pyridoxalphosphate-6-azophenyl-2 0 ,4 0 -disulfonic acid were less efficient. However, although P2Y receptor antagonists inhibited GFAP synthesis to a different extent they were unable to relieve the growth inhibition that accompanied induction of differentiation, whereas stimulation of the P2Y 12 receptor with 2-methylthioadenosine-5 0 -diphosphate inhibited GFAP expression and restored cell proliferation. Assay of the activity of phosphatidylinositol 3-kinase (PI 3-K), an enzyme required for GFAP expression [J. Neurochem. 76 (2001) 610], showed that RB2 inhibited this enzyme after cellular uptake, while suramin and pyridoxalphosphate-6-azophenyl-2 0 ,4 0 -disulfonic acid inhibited PI 3-K to a lesser extent. The intracellular concentration of RB2 increased in time and attained the IC 50 for PI 3-K inhibition (4 mM) after 40min incubation with 50 mM RB2. In conclusion, cAMP-induced differentiation in C6 cells is inhibited by activation of the P2Y 12 receptor. In addition, synthesis of GFAP is also inhibited by cellular uptake of non-selective nucleotide receptor antagonists that inhibit PI 3-K, a kinase required for the cAMP-dependent induction of differentiation. # 2004 Elsevier Inc. All rights reserved. fibrillary acidic protein; MAPK, mitogen-activated protein kinase; MEM, minimal essential medium; 2MeSADP, 2-methylthioadenosine-5 0 -diphosphate; PI 3-K, phosphatidylinositol 3-kinase; PI(3)P, phosphatidylinositol 3-phosphate; PIPES, 1,4-piperazinediethanesulfonic acid; PPADS, pyridoxalphosphate-6-azophenyl-2 0 ,4 0 -disulfonic acid; RB2, reactive blue 2.

Nephron, 1987

A 14-year-old boy with end-stage renal failure secondary to reflux nephropathy received a renal t... more A 14-year-old boy with end-stage renal failure secondary to reflux nephropathy received a renal transplant and was immunosuppressed with prednisone, azathioprine, and Minnesota antilymphoblast globulin, followed by cyclosporine A. A renal biopsy was performed 43 days post-transplantation because of fever and an elevated serum creatinine. The biopsy showed a mild interstitial lymphocytic infiltrate and immunosuppression was not changed. A second renal biopsy was performed 66 days after transplantation because of a persistent elevation of the serum creatinine following a cytomegalovirus (CMV) infection. CMV inclusions were seen by light microscopy (LM) in glomerular and peritubular capillary endothelial cells and tubular epithelial cells but no viral inclusions were present on the grids examined by electron microscopy (EM). However, the inclusions seen by LM were confirmed as CMV by immunohistochemistry, using polyclonal and monoclonal antibodies to CMV, and by in situ hybridization, using a biotinylated CMV DNA probe, emphasizing the usefulness of these techniques when studies by EM are not contributory.

Journal of General Virology, 2002

Cell-mediated immunity is thought to play a decisive role in protecting cats against feline infec... more Cell-mediated immunity is thought to play a decisive role in protecting cats against feline infectious peritonitis (FIP), a progressive and lethal coronavirus disease. In view of the potential of DNA vaccines to induce cell-mediated responses, their efficacy to induce protective immunity in cats was evaluated. The membrane (M) and nucleocapsid (N) proteins were chosen as antigens, because antibodies to the spike (S) protein of FIP virus (FIPV) are known to precipitate pathogenesis. However, vaccination by repeated injections of plasmids encoding these proteins did not protect kittens against challenge infection with FIPV. Also, a prime-boost protocol failed to afford protection, with priming using plasmid DNA and boosting using recombinant vaccinia viruses expressing the same coronavirus proteins. Because of the role of IL-12 in initiating cell-mediated immunity, the effects of co-delivery of plasmids encoding the feline cytokine were studied. Again, IL-12 did not meet expectations -on the contrary, it enhanced susceptibility to FIPV challenge. This study shows that DNA vaccination failed to protect cats against FIP and that IL-12 may yield adverse effects when used as a cytokine adjuvant.