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Clear Indication (clear + indication)

Distribution by Scientific Domains
Medical Sciences37%
Life Sciences18%
Chemistry14%
Earth and Environmental Science11%
Physics and Astronomy7%

Selected Abstracts

Anterior neural centres in echinoderm bipinnaria and auricularia larvae: cell types and organization

ACTA ZOOLOGICA, Issue 2 2002
Thurston C. Lacalli
Abstract Serial and interval electron micrograph series were used to examine the anterior part of the ciliary band system in the bipinnaria larva of Pisaster ochraceus and the auricularia larva of Stichopus californicus for evidence of ganglion-like organization. The bipinnaria has paired concentrations of Multipolar with Apical Processes (MAP) cells in this region that correspond in position with previously identified clusters of serotonergic and peptidergic neurones. MAP cells located in the centre of the band have well-developed apical processes, but no cilium. Those at the sides of the band have fewer processes, but some have recumbent cilia that extend under the glycocalyx, suggesting a sensory function. Comparable cell types are not found elsewhere in the band, a clear indication that the apical parts of the ciliary band system are organized in a distinctive fashion. Two neuronal cell types were identified in the apical region of the auricularia larva, a conventional bipolar neurone that corresponds with previously described serotonergic apical cells, and more numerous MAP cells for which there is no previous record and hence, no known transmitter. Previous immunocytochemical studies are summarized and re-examined in the light of these results. Relevant evolutionary issues are also discussed, but the data fail to provide strong evidence either for or against Garstang's hypothesis that the chordate brain and spinal cord derive from larval ciliary bands resembling those of modern echinoderms. [source]

Dissociating the role of the caudate nucleus and dorsolateral prefrontal cortex in the monitoring of events within human working memory

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2010
Jean-Sebastien Provost
Abstract There is evidence that the dorsolateral prefrontal cortex is involved in the monitoring of information held in memory whether it is self-ordered or externally triggered. However, the functional contribution of the caudate nucleus in the monitoring of events has not yet been studied. We have previously proposed that the striatum is involved when a novel self-initiated action needs to be generated. The present study aimed to test the hypothesis that the caudate nucleus is significantly more required when the monitoring is self-ordered as opposed to externally triggered. Self-ordered monitoring refers to keeping track of which items have been selected so far in order to perform the current selection. Externally triggered monitoring refers to keeping track of which items have been selected by an outside source. Thirteen healthy young adults were scanned using functional magnetic resonance imaging while performing a monitoring task with three conditions: self-ordered, externally triggered and recognition. As predicted, a significant increase of activity was found in the dorsolateral prefrontal cortex bilaterally when the self-ordered and externally triggered conditions were compared with the recognition condition. Most importantly, significantly increased activity was found in the right caudate nucleus when comparing the self-ordered with the recognition condition or with the externally triggered condition, but not when comparing the externally triggered with the recognition condition. We suggest that the caudate nucleus is involved in the planning of a self-initiated novel action, especially when no clear indication is given for the response choice, and that this may be the case across different domains of cognition. [source]

Interfertility between North American and European strains of Phlebiopsis gigantea

FOREST PATHOLOGY, Issue 3 2005
R. Grillo
Summary Thirteen homokaryotic strains of Phlebiopsis gigantea from Canada, six strains from the US and 10 strains from Europe were paired in all possible combinations in order to determine the degree of interfertility between them. The diagnosis of interfertility was based on the production of heterokaryotic fruit bodies in the pairings. Among the resulting 406 pairings, 253 (62%) fruited. Within the strains originating from Canada, USA and Europe, 64, 80 and 64% of the pairings fruited, respectively. The fruiting frequency in pairings between the Canadian and US strains was 65%, between the Canadian and European strains 55%, and between the US and European strains 67%. True hybridization between the European and North American P. gigantea was shown by analysing the single-spore progeny using DNA fingerprinting. In spite of the relatively low interfertility in pairings within and between continents, no clear indication of the existence of intersterility groups was found. The low interfertility is probably due to the ageing of the pure cultures and to deficient fruiting ability of certain heterokaryons on agar medium. The results strongly suggest that although the North American and European strains of P. gigantea show some differentiation they can be regarded as belonging to the same biological species. Résumé Treize souches homocaryotiques de Phlebiopsis gigantea du Canada, 6 des Etats-Unis et 10 d'Europe ont été confrontées par paires selon toutes les combinaisons possibles pour déterminer leur degré d'interfertilité. Le diagnostic d'interfertilité est basé sur la production de fructifications hétérocaryotiques dans les confrontations. Parmi les 406 paires, 253 (62%) ont fructifié. Ce pourcentage est de 64, 80 et 64% respectivement pour les souches du Canada, des Etats-Unis ou d'Europe entre elles. La fréquence de fructification pour les confrontations entre souches du Canada et des Etats-Unis est de 65%, entre souches européennes et canadiennes de 55% et entre souches des USA et d'Europe de 67%. La réalité de l'hybridation entre souches européennes et nord américaines a été démontrée par analyse de la descendance de spores par empreinte génétique. Malgré la relativement faible interfertilité dans les confrontations intra ou inter continents, l'existence de groupes d'interstérilité n'a pu être montrée. La faible interfertilité est probablement due au vieillissement des cultures pures et à une faible capacitéà fructifier sur milieu gélosé de certains hétérocaryons. Les résultats suggèrent fortement que malgré une certaine différenciation entre souches nord américaines et européennes de P. gigantea, celles-ci peuvent être considérées comme appartenant à la même espèce. Zusammenfassung Zur Bestimmung der Interfertilität wurden 13 homokaryotische Isolate von Phlebiopsis gigantea aus Kanada, 6 aus den USA und 10 aus Europa in allen möglichen Kombinationen miteinander gekreuzt. Der Erfolg der Kreuzungen wurde anhand der Bildung von heterokaryotischen Fruchtkörpern beurteilt. Bei insgesamt 406 Kreuzungen wurden in 253 Fällen (62%) Fruchtkörper gebildet. Unter den Stämmen aus Kanada, den USA und Europa kam es in 64, 80 und 64% der Fälle zur Fruchtkörperbildung. Bei Paarungen zwischen Isolaten aus Kanada und den USA fruktifizierten 65%, bei Paarungen zwischen Isolaten aus Kanada und Europa waren dies 55%, Paarungen zwischen Isolaten aus den USA und Europa fruktifizierten zu 67%. Die echte Hybridisierung zwischen europäischen und nordamerikanischen Isolaten von P. gigantea wurde durch Analysen der Einzelsporisolate aus den Fruchtkörpern durch DNA-Fingerprinting nachgewiesen. Trotz der relativ geringen Interfertilität innerhalb und zwischen den Kontinenten wurden keine klaren Hinweise auf die Existenz von Intersterilitätsgruppen gefunden. Die geringe Interfertilität ist möglicherweise durch eine Degeneration der Kulturen in vitro und durch die fehlende Fähigkeit mancher Heterokaryen zur Fruchtkörperbildung auf Agarmedien erklärbar. Die Ergebnisse zeigen, dass Isolate von P. gigantea aus Nordamerika und Europa trotz einer gewissen geographischen Differenzierung zu einer einzigen biologischen Art gehören. [source]

Use of fresh-frozen plasma at Royal Darwin Hospital: a retrospective audit

INTERNAL MEDICINE JOURNAL, Issue 9 2008
S. Moylan
Abstract Background:, The aim of the study was to assess the appropriateness of use of fresh-frozen plasma (FFP) at Royal Darwin Hospital against the National Health and Medical Research Council and Australian and New Zealand Society for Blood Transfusion guidelines. Methods:, A retrospective review of blood product request forms, online pathology storage system data, pathology records and clinical notes between 1 January 2006 and 31 December 2006 was carried out. The appropriateness of requests was assessed against existing guidelines. The percentage of appropriate and inappropriate FFP transfusions was obtained. Results:, Six hundred and forty-eight of 950 units (68%) of FFP were used with an appropriate indication as per National Health and Medical Research Council/Australian and New Zealand Society for Blood Transfusion guidelines. Of the remaining units, 14% (137 units) was given without a clear indication and a decision of appropriateness could not be established for 17% (165 units) because of inadequate clinical or pathology information (e.g. coagulation results). Multiple issues around prescribing practice were identified. Conclusion:, There is significant use of FFP at Royal Darwin Hospital without clear clinical indication. The employment of a transfusion nurse to monitor use of FFP (and other blood products) and provide education is aimed at improving transfusion efficiency and patient safety. [source]

Sub-Micrometer Scale Periodic Porous Cellular Structures: Microframes Prepared by Holographic Interference Lithography,

ADVANCED MATERIALS, Issue 22 2007
M. Maldovan
The ubiquity of multifunctional cellular solids in both natural and engineered materials is a clear indication of the importance of such materials. The mechanical behavior of these structures is the most common critical functionality across different applications. In this Communication, we establish the effective elastic properties of periodic bicontinuous solid/air structures that can be fabricated at small length scales by interference lithography and compare their properties with standard models. [source]

Fatigue behaviour of industrial polymers , a microbeam small-angle X-ray scattering investigation

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3-1 2003
Stephan V. Roth
The results of a microbeam small-angle X-ray scattering investigation performed at ID13/ESRF on the machine fatigue induced by short-term high force bending of an industrial polystyrene sample are presented. A clear indication of craze formation in the deformation zone is seen. For this zone the results suggest a model of cylindrical voids, their radii following a lognormal distribution. Furthermore, the craze's orientation shows a locally varying angular distribution around the axis normal to the force direction. [source]

Crossing boundaries, re-defining care: the role of the critical care outreach team

JOURNAL OF CLINICAL NURSING, Issue 3 2002
MAUREEN COOMBS BSc MSc PhD RN
,,There is clear indication that both government and professional policy in the United Kingdom supports a radical change in the role of healthcare practitioners, with a move towards a patient-focused service delivered by clinical teams working effectively together. ,,Recent health service imperatives driving the agenda for flexible clinical teams have occurred simultaneously with an increased public and political awareness of deficits in availability of critical care services. ,,Against this policy backdrop, working across professional and organizational boundaries is fundamental to supporting quality service improvements. In the acute care sector, the development of critical care outreach teams is an innovation that seeks to challenge the traditional support available for sick ward patients. ,,Activity data and observations from the first 6-month evaluation of two critical care outreach teams identify the need for clinical support and education offered by critical care practitioners to ward-based teams. ,,The experiences from such flexible clinical teams provides a foundation from which to explore key issues for intradisciplinary and interdisciplinary working across clinical areas and organizational boundaries. ,,Adopting innovative approaches to care delivery, such as critical care outreach teams, can enable clinical teams and NHS trusts to work together to improve the quality of care for acutely ill patients, support clinical practitioners working with this client group, and develop proactive service planning. [source]

Effects of ground cover (straw and compost) on the abundance of natural enemies and soil macro invertebrates in vineyards

AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2007
Linda J. Thomson
Abstract 1,Herbicides are commonly applied under grapevines in Australia to remove weeds and thereby to avoid water loss through transpiration. 2,Interest in sustainability promotes a reduction in chemical inputs, including herbicides, leading to trials with surface mulches to suppress weeds. 3,Surface mulches may also influence the abundance of a range of invertebrates. Potentially, an increase in natural enemies will contribute to pest control and encourage a reduction in pesticide application. 4,We used three trapping methods and direct soil sampling to assess invertebrates at ground level, in the canopy and in the soil to determine the influence of mulch on natural enemies, potential pests and soil macroinvertebrates, including earthworms. 5,Collections sorted to family demonstrated that the addition of straw or compost mulches increased natural enemies collected with pitfall traps and soil organisms. However, there was no clear indication of the overall superiority of either mulch. 6,Abundance of ground beetles, parasitoid Hymenoptera and spiders collected with pitfall traps were increased by the addition of mulches. In the canopy, predatory and parasitic Diptera and predatory Hemiptera increased after mulching. 7,Earthworms collected by hand sorting soil increased with straw mulching. 8,No influence on pests was detected. Although Lepidoptera and Sigmurethra, collected in pitfall traps, increased with straw mulching, neither included pest species. 9,The results are discussed with reference to the potential economic impact of mulches. [source]

Use of parenteral nutrition in hospitals in the North of England

JOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 1 2007
S. A. Hearnshaw
Abstract Background, Parenteral nutrition (PN) is a costly technology used widely to provide nutrition to patients who have an inaccessible or nonfunctioning intestine. A prospective survey was designed to collect data on PN for inpatients to study the current use of PN, its complications and outcomes in the north of England. The study objectives were to use the Northern Nutrition Network to collect data from all acute hospital inpatients prospectively receiving PN, for 3 months and to provide evidence for current PN practice, and to establish whether this is in line with recognized published clinical guidelines. Methods, Using a paper-based collection tool information was recorded on aspects of PN including: total inpatient episodes, patient demographics, indications, duration, venous access used, complications, number returning to enteral feeding and mortality. The presence of a nutrition support team was also recorded. Results, Data on 193 patient PN episodes were recorded totalling 1708 patient days. The median age of the patients was 67 years. Of these, 158 (82%) were deemed to have a clear indication for PN using the indications cited in the NICE guidelines (http://www.nice.org.uk). The median duration of PN was 7 days (range 1,93). Thirty (16%) patients developed complications due to PN, 23 (12%) had catheter infections which were most common on medical wards. Thirty-nine (20%) patients died within 28 days of PN starting; no deaths were attributable to PN. A total of 118 (61%) patients returned to full enteral feeding. Only three hospitals had nutrition support teams, which had no significant effect on outcomes. Conclusions, Parenteral nutrition practice in the north of England is generally in line with current guidelines, however, only three of 15 hospitals had nutrition support teams. Eighteen per cent of patients did not have a clearly documented indication for PN and 15% developed a complication, most often a catheter-related infection. [source]

Efficacy and safety of oral ridogrel in the treatment of ulcerative colitis: two multicentre, randomized, double-blind studies

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2002
G. N. J. Tytgat
Background: Ridogrel at low doses inhibits thromboxane synthase. Oral ridogrel, from 5 mg once daily to 150 mg twice daily, improves the endoscopic appearance of colonic mucosa and clinical manifestations in mild to moderate ulcerative colitis. Aim: One US trial and one international trial were conducted to determine the effect of ridogrel on mild to severe active ulcerative colitis. Methods: Two 12-week, double-blind, randomized, parallel-group trials were conducted. A US trial compared 0.5 mg, 2.5 mg and 5 mg of ridogrel once daily with placebo. An international trial compared 0.5 mg of ridogrel once daily with 2.5 mg and 5.0 mg of ridogrel once daily and 800 mg of mesalazine (known as mesalamine in the USA) three times daily. The primary efficacy outcome measure was the rate of complete remission. Results: In the US trial, complete remission was achieved in 20.8% of patients in the 0.5 mg ridogrel group, 17.9% in the 2.5 mg ridogrel group, 20.6% in the 5.0 mg ridogrel group and 13.6% in the placebo group. In the international trial, 14.4% of patients in the 0.5 mg ridogrel group, 19.6% in the 2.5 mg ridogrel group, 19.4% in the 5.0 mg ridogrel group and 16.4% in the mesalazine group experienced complete remission. In the international trial, rates of complete remission at the end-point were greater in the 2.5 mg and 5.0 mg ridogrel groups than in the 0.5 mg ridogrel group, but the differences were not statistically significant. In the US trial, rates of complete remission at the end-point were greater in the 2.5 mg and 5.0 mg ridogrel groups than in the placebo group, but the differences were not statistically significant. Approximately 30% of the patients in each group discontinued treatment before the 12-week end-point owing to a lack of therapeutic response. All doses of ridogrel were well tolerated and comparable with placebo or mesalazine in terms of safety. Conclusions: No significant differences in the primary efficacy outcome measure were found between either the 2.5 mg or the 5.0 mg dose of ridogrel and placebo in the US trial and between either the 2.5 mg or the 5.0 mg dose of ridogrel and the 0.5 mg dose of ridogrel, a surrogate dose for placebo, in the international trial. There was no clear indication in either trial of an effective dose of ridogrel in the treatment of ulcerative colitis. [source]

Towards a European registry of severe allergic reactions: current status of national registries and future needs

ALLERGY, Issue 6 2010
M. Worm
To cite this article: Worm M, Timmermans F, Moneret-Vautrin A, Muraro A, Malmheden Yman II, Lövik M, Hattersley S, Crevel R. Towards a European registry of severe allergic reactions: current status of national registries and future needs. Allergy 2010; 65: 671,680. Abstract The incidence of severe allergic reactions is largely unknown and information about triggering allergens, aggravating factors, demography of patients and medical care is lacking. A European wide registry could provide a powerful tool to improve the management of severe allergic reactions from both a medical and a public health perspective. Analysis of existing registries regarding the type and quality of data being collected was used to develop a plan for a pan-European registry, including the type of system to be used and the range of data to be entered. Surveillance will provide evidence for the efficacy of risk management measures and may identify the emergence of new allergenic foods, and aid monitoring of novel foods, ingredients and technologies. Patients need a clear indication of factors that may increase their risk of having an adverse reaction, which such a registry can help compile. Based on the collected data, food businesses will be able to develop educational programmes for allergen risk assessment and allergen risk communication. Finally, and most importantly preventive measures can be developed and government agencies receive population based data which may be relevant for legislative purposes. [source]

Target rocks, impact glasses, and melt rocks from the Lonar impact crater, India: Petrography and geochemistry

METEORITICS & PLANETARY SCIENCE, Issue 9-10 2005
Shiloh Osae
A representative set of target basalts, including the basalt flows excavated by the crater, and a variety of impact breccias and impact glasses, were analyzed for their major and trace element compositions. Impact glasses and breccias were found inside and outside the crater rim in a variety of morphological forms and shapes. Comparable geochemical patterns of immobile elements (e.g., REEs) for glass, melt rock and basalt indicates minimal fractionation between the target rocks and the impactites. We found only little indication of post-impact hydrothermal alteration in terms of volatile trace element changes. No clear indication of an extraterrestrial component was found in any of our breccias and impact glasses, indicating either a low level of contamination, or a non-chondritic or otherwise iridium-poor impactor. [source]

Haloes around edge-on disc galaxies in the Sloan Digital Sky Survey

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2004
Stefano Zibetti
ABSTRACT We present a statistical analysis of halo emission for a sample of 1047 edge-on disc galaxies imaged in five bands by the Sloan Digital Sky Survey (SDSS). Stacking the homogeneously rescaled images of the galaxies, we can measure surface brightnesses as deep as ,r, 31 mag arcsec,2. The results strongly support the almost ubiquitous presence of stellar haloes around disc galaxies, whose spatial distribution is well described by a power law ,,r,3, in a moderately flattened spheroid (c/a, 0.6). The colour estimates in g,r and r,i, although uncertain, give a clear indication for extremely red stellar populations, hinting at old ages and/or non-negligible metal enrichment. These results support the idea of haloes being assembled via early merging of satellite galaxies. [source]

Use of intravenous sedation in the management of patients with high blood pressure

ORAL SURGERY, Issue 3 2009
S. Woolcombe
Abstract Aim:, We aim to determine the prevalence of undiagnosed/poorly controlled hypertension and study the population demographics. We also aim to study the effects of intravenous midazolam on peri-operative blood pressure and pulse. Finally, we aim to assess the value of screening for hypertension and determine the degree of white coat hypertension. Material and methods:, A cohort of 83 patients with a pre-assessment blood pressure recording ,160/100 mmHg was studied. Oral surgery treatment was performed under intravenous sedation with midazolam or local anaesthesia alone where sedation was contraindicated. Blood pressure and pulse were monitored throughout surgery. Following treatment, patients were advised to attend their General Practitioner (GP) for assessment of their blood pressure and information regarding the outcome of this visit was requested. Results:, Seventy-three percent of the cohort had no previous diagnosis of hypertension. The use of intravenous midazolam significantly reduced peri-operative blood pressure compared with local anaesthesia alone [reduction in systolic blood pressure (BP) of 40 mmHg and diastolic BP of 21 mmHg]. Fifty percent of those who attended their GP received active treatment for hypertension at the first visit. A further 25% were kept under review. Blood pressure measurements at hospital pre-assessment were substantially higher than those recorded by GPs. Conclusion:, A clear indication exists for the use of intravenous sedation with midazolam for oral surgery procedures in patients with high blood pressure. There is a significant prevalence of undiagnosed and poorly controlled hypertension. Blood pressure screening in the dental setting is a valuable tool for identifying hypertensive patients. White coat hypertension is significantly greater in the oral surgery department than at the GP surgery. [source]

Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker Implantation

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2002
MARTINO MARTINELLI
MARTINELLI, M., et al.: Criteria for Pacemaker Explant in Patients Without a Precise Indication for Pacemaker Implantation. Unnecessary pacemaker implantation may cause significant social and psychological consequences, the inconvenience of periodic office visits, and the expense of pulse generator replacement. Establishing adequate criteria for explanting pacemakers is crucial and has not yet been described. This study presents the results of a study protocol for explanting the pacemaker in patients without a clear indication for pacemaker implantation. Seventy pacemaker users without a clear reason for the implantation were included in the study conducted from August 1986 to November 1998 and were prospectively followed. The investigation consisted of clinical and neurological evaluations, echocardiogram, exercise testing, and tilt table testing. When these tests were negative, the pulse generator energy and stimulation rates were reprogrammed to the lowest values. Periodic Holter monitoring was conducted during follow-up. When asymptomatic for 1 year, patients underwent an electrophysiological evaluation of sinus and atrioventricular junction function and ventricular vulnerability. When the electrophysiological study was negative, pacemaker explantation was performed. Of the 70 patients, 35 had their pacemaker explanted; 3 were excluded due to a positive tilt table test and electrophysiological study, and 3 are waiting for pacemaker explantation. Mean follow-up after pacemaker explantation was 30.3 months, and all patients remained asymptomatic, except for one patient who died of a noncardiac cause. Critical analysis of pacemaker users without a well-established indication is justified because it may allow pacemaker explant in a significant proportion of these patients, and it may bring considerable social, economic, and psychological benefits. [source]

The Preauricular Sinus: A Review of its Clinical Presentation, Treatment, and Associations

PEDIATRIC DERMATOLOGY, Issue 3 2004
Noah S. Scheinfeld M.D.
Usually asymptomatic, they manifest as small dells adjacent to the external ear near the anterior margin of the ascending limb of the helix, most frequently on the right side. Preauricular sinuses can be either inherited or sporadic. When inherited, they show an incomplete autosomal dominant pattern with reduced penetrance and variable expression. They may be bilateral, increasing the likelihood of being inherited, in 25,50% of cases. Preauricular sinuses are features of other conditions or syndromes in 3,10% of cases, primarily in association with deafness and branchio-oto-renal (BOR) syndrome. When other congenital anomalies coexist with these sinuses, auditory testing and renal ultrasound should be considered. Sinuses may become infected, most commonly with gram-positive bacteria, in which case their exudates should be cultured and appropriate antibiotics administered. Recurrent infection is a clear indication for complete excision and provides the only definitive cure. Recurrence rates after surgery range from 9% to 42%. Meticulous excision by an experienced head and neck surgeon minimizes the risk of recurrence. [source]

Identification of organic hydroperoxides and hydroperoxy acids in secondary organic aerosol formed during the ozonolysis of different monoterpenes and sesquiterpenes by on-line analysis using atmospheric pressure chemical ionization ion trap mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2009
Marc-Christopher Reinnig
On-line ion trap mass spectrometry (ITMS) enables the real-time characterization of reaction products of secondary organic aerosol (SOA). The analysis was conducted by directly introducing the aerosol particles into the ion source. Positive-ion chemical ionization at atmospheric pressure (APCI(+)) ITMS was used for the characterization of constituents of biogenic SOA produced in reaction-chamber experiments. APCI in the positive-ion mode usually enables the detection of [M+H]+ ions of the individual SOA components. In this paper the identification of organic peroxides from biogenic volatile organic compounds (VOCs) by on-line APCI-ITMS is presented. Organic peroxides containing a hydroperoxy group, generated by gas-phase ozonolysis of monoterpenes (, -pinene and , -pinene) and sesquiterpenes (, -cedrene and , -copaene), could be detected via on-line APCI(+)-MS/MS experiments. A characteristic neutral loss of 34,Da (hydrogen peroxide, H2O2) in the on-line MS/MS spectra is a clear indication for the existence of an organic peroxide, containing a hydroperoxy functional group. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Raman Spectroscopic Analysis of Ancient Egyptian Pigments

ARCHAEOMETRY, Issue 4 2001
A. Rosalie David
The application of FT-Raman spectroscopy and visible Raman microscopy to the non-destructive analysis of pigment specimens excavated from Tell el Amarna by Flinders Petrie in the 1890s has provided information about the chemical composition of the materials used by XVIIIth Dynasty artists in the New Kingdom at the time of King Akhenaten, c. 1340 bc. Comparison of the Raman spectra of the samples labelled ,red and yellow ochre' with documented, archival material from geological collections provided a clear indication of the materials used in the iron(III) oxide/hydroxide system, including ,-hematite, goethite, maghemite, magnetite and lepidocrocite. The yellow,orange specimen labelled ,realgar' proved to be a mixture of realgar and pararealgar; since the specimen had been sheltered from light since its excavation, this could indicate that the ancient Egyptian artists recognized the colour variation and may have used this to effect in their decorations. A specimen of yellow ochre contained goethite, ,-FeO.OH, with particles of crystalline, highly ordered graphite; in contrast, the red ochre specimens contained amorphous carbon particles. [source]

New Insight into the Mode of Action of Nickel Superoxide Dismutase by Investigating Metallopeptide Substrate Models

CHEMISTRY - A EUROPEAN JOURNAL, Issue 2 2009
Daniel Tietze M.
Abstract For the first time, the existence of a substrate adduct of a nickel superoxide dismutase (NiSOD) model, based on the first nine residues from the N terminus of the active form of Streptomyces coelicolor NiSOD, has been proven and the adduct has been isolated. This adduct is based on the cyanide anion (CN,), as a substrate analogue of the superoxide anion (O2.,), and the nickel metallopeptide H-HCDLPCGVY-NH2 -Ni. Spectroscopic studies, including IR, UV/Vis, and liquid- and solid-state NMR spectroscopy, show a single nickel-bound cyanide anion, which is embedded in the metallopeptide structure. This complex sheds new light on the question of whether the mode of action of the NiSOD enzyme is an inner- or outer-sphere mechanism. Whereas discussion was previously biased in favor of an outer-sphere electron-transfer mechanism due to the fact that binding of cyanide or azide moieties to the nickel active site had never been observed, our results are a clear indication in favor of the inner-sphere electron-transfer mechanism for the disproportionation of the O2., ion, whereby the substrate is attached to the Ni atom in the active site of the NiSOD. [source]

Metal/Ceramic Interface Properties and Their Effects on SOFC Development

FUEL CELLS, Issue 6 2009
F. Tietz
Abstract Development of solid oxide fuel cells (SOFCs) involves multidisciplinary research, which needs input from many directions. As an example, this contribution describes the influence of basic metallurgical experiments on the selection or the modification of specific materials used in SOFCs. Wettability studies, although typically regarded as model experiments, give clear indications of the combinations of materials, which show better compatibility and might be more successfully integrated in SOFC designs, especially when metal/ceramic interfaces are involved. Various material combinations, i.e. anode cermets, glass/steel and ceramic/silver/steel compounds, are discussed in more detail showing the impact of fundamental studies on the SOFC development actually applied. This work gives a short overview on the basic aspects of selected material combinations. [source]

Benzodiazepines prescription in Dakar: a study about prescribing habits and knowledge in general practitioners, neurologists and psychiatrists

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2006
Amadou Moctar Dièye
Abstract Benzodiazepines are relatively well-tolerated medicines but can induce serious problems of addiction and that is why their use is regulated. However, in developing countries like Senegal, these products are used without clear indications on their prescription, their dispensation or their use. This work focuses on the prescription of these medicines with a view to make recommendations for their rational use. Benzodiazepine prescription was studied with psychiatrists or neurologists and generalists in 2003. Specialist doctors work in two Dakar university hospitals and generalists in the 11 health centres in Dakar. We did a survey by direct interview with 29 of 35 specialists and 23 of 25 generalists. All doctors were interviewed in their office. The questionnaire focused on benzodiazepine indications, their pharmacological properties, benzodiazepines prescribed in first intention against a given disease and the level of training in benzodiazepines by doctors. Comparisons between specialists and generalists were made by chi-square test. Benzodiazepines were essentially used for anxiety, insomnia and epilepsy. With these diseases, the most benzodiazepines prescribed are prazepam against anxiety and insomnia and diazepam against epilepsy. About 10% of doctors do not know that there is a limitation for the period of benzodiazepine use. The principal reasons of drugs choice are knowledge of the drugs, habit and low side effects of drugs. All generalists (100%) said that their training on benzodiazepines is poor vs. 62.1% of specialists, and doctors suggest seminars, journals adhesions and conferences to complete their training in this field. There are not many differences between specialists and generalists except the fact that specialists prefer prazepam in first intention in the insomnia treatment where generalists choose bromazepam. In addition, our survey showed that specialists' training in benzodiazepines is better than that of generalists. Overall, benzodiazepine prescription poses problems particularly in training, and national authorities must take urgent measures for rational use of these drugs. [source]

Molecular Transport Junctions: Clearing Mists,

ADVANCED MATERIALS, Issue 1 2007
M. Lindsay
Abstract Recent progress in the measurement and modeling of transport in molecular junctions has been very significant. Tunnel transport in the Landauer,Imry regime is now broadly understood for several systems, although a detailed understanding of the role of contact geometry is still required. We overview some clear indications from recent research and note the quite reasonable agreement between measured and calculated conductance in metal,molecule,metal junctions. The next challenge lies in obtaining a microscopic understanding of charge transport that involves reduction or oxidation of molecules. [source]

Genetic structure and gene flow in wild beet populations: the potential influence of habitat on transgene spread and risk assessment

JOURNAL OF APPLIED ECOLOGY, Issue 6 2006
A. N. CURETON
Summary 1The consequences of the movement of transgenes from genetically modified (GM) crops into wild populations of plants continues to be of concern to ecologists and conservationists because of the possible threat posed to those populations in terms of their continued survival and because of the further knock-on effects that might occur to habitats in which they occur. 2We examined five UK sea beet Beta vulgaris ssp. maritima populations from each of two major habitat types, cliff top and drift line. We assessed population genetic parameters, genetic diversity, gene flow, population differentiation and isolation by distance, to enable determination of the likelihood and consequences of spread to wild populations of genes from cultivated sugar beet group Beta vulgaris ssp. vulgaris, which could in the future be transgenic. 3Drift line populations were more diverse than cliff top populations and also showed greater levels of gene flow. 4Isolation by distance was identified in both habitats, but the relationship between genetic and geographical distance was detectable over longer distances for drift line populations. However, clear indications of vicariance (the subdivision of a population into distinct taxa by the appearance of a geological barrier) between cliff and drift line populations were also evident, because of the restriction of gene flow between the two habitats occurring more in one direction than the other. 5Synthesis and applications. The likelihood of transgene spread from crop to wild populations is habitat dependent and conservation management decisions could therefore vary from one population to another, for example water courses were found to facilitate seed dispersal. This should be taken into account when estimating isolation distances for GM beet, and when predicting transgene frequencies (exposure estimates) for environmental risk assessments of GM beet. [source]

Use of micreosatellite markers for identification of indigenous brown trout in a geographical region heavily influenced by stocked domensticated trout

JOURNAL OF FISH BIOLOGY, Issue 5 2001
N. G. Fritzner
Based on estimates of genetic differentiation between populations, assignment tests and analysis of isolation by distance, stocked populations of brown trout Salmo trutta of Funen Island, Denmark, had been genetically affected by domesticated trout, whereas the stocking of wild exogenous trout into one of the rivers had little or no impact. At the same time, there were clear indications of remaining indigenous gene pools in the Funen populations. The management implications of these findings are discussed and changes in trout release activity are recommended to avoid further mixing of trout gene pools. [source]

Contrasting metamorphic histories of lenses of high-pressure rocks and host migmatites with a flat orogenic fabric (Bohemian Massif, Czech Republic): a result of tectonic mixing within horizontal crustal flow?

JOURNAL OF METAMORPHIC GEOLOGY, Issue 6 2008
TÍPSKÁ
Abstract Migmatites with sub-horizontal fabrics at the eastern margin of the Variscan orogenic root in the Bohemian Massif host lenses of eclogite, kyanite-K-feldspar granulite and marble within a matrix of migmatitic paragneiss and amphibolite. Petrological study and pseudosection modelling have been used to establish whether the whole area experienced terrane-wide exhumation of lower orogenic crust, or whether smaller portions of higher-pressure lower crust were combined with a lower-pressure matrix. Kyanite-K-feldspar granulite shows peak conditions of 16.5 kbar and 850 °C with no clear indications of prograde path, whereas in the eclogite the prograde path indicates burial from 10 kbar and 700 °C to a peak of 18 kbar and 800 °C. Two contrasting prograde paths are identified within the host migmatitic paragneiss. The first path is inferred from the presence of staurolite and kyanite inclusions in garnet that contains preserved prograde zoning that indicates burial with simultaneous heating to 11 kbar and 800 °C. The second path is inferred from garnet overgrowths of a flat foliation defined by sillimanite and biotite. Garnet growth in such an assemblage is possible only if the sample is heated at 7,8 kbar to around 700,840 °C. Decompression is associated with strong structural reworking in the flat fabric that involves growth of sillimanite in paragneiss and kyanite-K-feldspar granulite at 7,10 kbar and 750,850 °C. The contrasting prograde metamorphic histories indicate that kilometre-scale portions of high-pressure lower orogenic crust were exhumed to middle crustal levels, dismembered and mixed with a middle crustal migmatite matrix, with the simultaneous development of a flat foliation. The contrasting P,T paths with different pressure peaks show that tectonic models explaining high-pressure boudins in such a fabric cannot be the result of heterogeneous retrogression during ductile rebound of the whole orogenic root. The P,T paths are compatible with a model of heterogeneous vertical extrusion of lower crust into middle crust, followed by sub-horizontal flow. [source]

Admixture facilitates adaptation from standing variation in the European aspen (Populus tremula L.), a widespread forest tree

MOLECULAR ECOLOGY, Issue 8 2010
DULCINEIA DE CARVALHO
Abstract Adaptation to new environments can start from new mutations or from standing variation already present in natural populations. Whether admixture constrains or facilitates adaptation from standing variation is largely unknown, especially in ecological keystone or foundation species. We examined patterns of neutral and adaptive population divergence in Populus tremula L., a widespread forest tree, using mapped molecular genetic markers. We detected the genetic signature of postglacial admixture between a Western and an Eastern lineage of P. tremula in Scandinavia, an area suspected to represent a zone of postglacial contact for many species of animals and plants. Stringent divergence-based neutrality tests provided clear indications for locally varying selection at the European scale. Six of 12 polymorphisms under selection were located less than 1 kb away from the nearest gene predicted by the Populus trichocarpa genome sequence. Few of these loci exhibited a signature of ,selective sweeps' in diversity-based tests, which is to be expected if adaptation occurs primarily from standing variation. In Scandinavia, admixture explained genomic patterns of ancestry and the nature of clinal variation and strength of selection for bud set, a phenological trait of great adaptive significance in temperate trees, measured in a common garden trial. Our data provide a hitherto missing direct link between past range shifts because of climatic oscillations, and levels of standing variation currently available for selection and adaptation in a terrestrial foundation species. [source]

The role of glitazones in management of type 2 diabetes.

OBESITY REVIEWS, Issue 5 2007
A DREAM or a nightmare?
Summary Glitazones have been introduced as second-step medication for type 2 diabetics, and today rosiglitazone and pioglitazone are blockbuster drugs. However, glitazones may have important adverse effects that outweight their beneficial effect on insulin resistance and glycemia. The larger trials have shown that glitazones produce a weight gain of 4,5 kg over 3,4 years of treatment, and the weight gain cannot be explained by fluid retention. Moreover, the risk of myocardial infarction is increased by 43% by rosiglitazone, and there are clear indications of increased risk of heart failure. Furthermore, there are studies to suggest that glitazones also increase the risk of fractures, whereas an increased cancer risk is not supported. In conclusion, given the increased cardiovascular risk, and that a weight gain of few kg can increase risks of cancer of the breast, colon, prostate and endometrium, the use of glitazones should be questioned. There is a need for more safe and weight neutral drugs to treat type 2 diabetes. [source]