Very Active (very + active)

Distribution by Scientific Domains

Terms modified by Very Active

  • very active area
  • very active catalyst

  • Selected Abstracts


    Effects of the Little Ice Age on avalanche boulder tongues in the French Alps (Massif des Ecrins)

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2004
    Vincent Jomelli
    Abstract Lichens of the subspecies Rhizocarpon geographicum s.l were measured on 25 avalanche boulder tongues in the Massif des Ecrins to elucidate the Little Ice Age history of avalanche activity. Results show: (1) an increase of lichen size from the median to the distal zone of deposits, and a decrease from the edges to the centre; (2) three types of lichen settlement. From the uppermost to the median zone, lichens are absent, because avalanche activity is very active. Down-slope, lichens occur in two different zones: the median zone is colonized by 5,20 mm size lichens on sides of blocks protected from the abrasional action of avalanches, while in the distal zone lichen diameters are largest (>30 mm) and occur on all sides of the blocks. The spatial distribution of the lichens and their size according to elevation make it possible to distinguish different phases during which avalanche activity has increased. At high elevation, the avalanche activity was at a maximum before ad 1650 and between ad 1730 and 1830. During these two periods avalanches had suf,cient magnitude to reach the basal zone of the deposits. At low elevation since ad 1650 the magnitude and frequency of avalanches have declined. Copyright © 2004 John Wiley & Sons, Ltd. [source]


    Biology of Anagrus atomus (Hymenoptera: Mymaridae), an egg parasitoid of the grape leafhopper Arboridia kermanshah (Homoptera: Cicadellidae)

    ENTOMOLOGICAL SCIENCE, Issue 3 2004
    Shahram HESAMI
    Abstract Biology, morphology and oviposition behavior of Anagrus atomus (Linnaeus), an egg parasitoid of the grape leafhopper Arboridia kermanshah Dlabola in Isfahan, Iran, were investigated. Adults were smaller than those so far reported from other regions. Females continuously drummed on plant surfaces with their antennae to search for host eggs. Parasitoid eggs hatched 2,3 days after oviposition, and A. atomus had two larval instars. First instar larvae were sacciform and immobile. Second instar larvae appeared 4 days after oviposition and were very active, and doubled their body length. The prepupal and pupal stages lasted for 1 and 5,6 days, respectively. Adult emergence began 16 days after oviposition, and peaked on day 17. [source]


    Alkyne Hydroarylations with Chelating Dicarbene Palladium(II) Complex Catalysts: Improved and Unexpected Reactivity Patterns Disclosed Upon Additive Screening,

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2009
    Andrea Biffis
    Abstract Palladium(II) complexes with a ligand set made from a chelating N-heterocyclic dicarbene ligand and two weakly coordinating anions (generally introduced in situ upon addition of 2 equiv. of a suitable silver salt) were found to be very active and selective catalysts for the room-temperature hydroarylation of alkynes at low catalyst loading (0.1 mol-%). Moreover, the screening of various strong acids as reaction promoters revealed that both the strength of the acid and the coordinating ability of its conjugated base influence the catalytic performance. Most remarkably, the use of HBF4 together with a dicarbene Pd complex catalyst provides a dramatic change in the selectivity of the reaction, with the prevalent formation of a product stemming from the insertion of two molecules of alkyne into the aromatic C,H bond. The results presented herein highlight the fact that the dicarbene ligand, apart from stabilising the catalyst, is also able to enhance catalytic activity and, most notably, to steer the reaction selectivity towards novel products. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


    Output of the Spanish Cortes (1979,2000): A case of adaptation to party government

    EUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 4 2006
    MANUEL SANCHEZ DE DIOS
    It mainly examines the output of the lower chamber due to the asymmetrical bicameralism and weak status of the Senate. In Spain, the legislative output has been dependent on different situations of party government. In general terms, the Cortes have been always very active in controlling the executive and its participation in law-making was highly relevant when there was a minority government. Because parties are central actors in parliament and due to the strong party discipline in the Spanish case, the author mainly studied parliament output from the viewpoint of strategies of opposition parties. Sometimes parties behaved in parliament procedures in a competitive way, while in others they behave cooperatively. There was a great variety of patterns of strategic behaviour on account of the different situations of party government and the diverse opposition parties. Half of the parliaments had minority governments in which minority parties played a very important role by supporting the government in parliament; however, the main opposition party was never the same since there were two changes of government. [source]


    Encapsulation and Ostwald Ripening of Au and Au,Cl Complex Nanostructures in Silica Shells,

    ADVANCED FUNCTIONAL MATERIALS, Issue 13 2006
    W. Lou
    Abstract We report a general template strategy for rational fabrication of a new class of nanostructured materials consisting of multicore shell particles. Our approach is demonstrated by encapsulating Au or Pt nanoparticles in silica shells. Other superstructures of these hollow shells, like dimers, trimers, and tetramers can also be formed by nanoparticle-mediated self-assembly. We have also used the as-prepared multicore Au,silica hollow particles to perform the first studies of Ostwald ripening in confined microspace, in which chloride was found to be an efficient mediating ligand. After treatment with aqua regia, Au,Cl complex is formed inside the shell, and is found to be very active under in,situ transmission electron microscopy observations while confined in a microcell. This aspect of the work is expected to motivate further in,situ studies of confined crystal growth. [source]


    Exploring the nutrition and lifestyle knowledge, attitudes and behaviour of student home economics teachers: baseline findings from a 4-year longitudinal study

    INTERNATIONAL JOURNAL OF CONSUMER STUDIES, Issue 4 2008
    Mary Isobelle Mullaney
    Abstract It is widely acknowledged that obesity linked with reduced exercise contributes to health problems, and that, conversely, individuals who embark on weight reducing diets may become deficient in key nutrients. It is often advocated that these problems, which can be grouped together as poor dietary practice, be tackled through education. This study attempts to examine the relationship between nutrition education and lifestyle behaviours in a select group of third level students. The Irish Home Economics curriculum aims to teach secondary school pupils about nutrition and lifestyle practices conducive to health. However, the attitudes and lifestyle practices of those teaching this subject have never been examined in Ireland. The purpose of the present 4-year longitudinal study, whose first year findings are presented here, is to investigate the nutrition and lifestyle knowledge, attitudes and behaviours of a cohort of Irish student home economics teachers over the 4 years of their Bachelor of Education (Home Economics) degree course. The study was designed to explore possible changes in knowledge, attitudes and practices over the course of their professional education. Nutritional knowledge was measured using a 220-question adapted version of the test devised by Parmenter and Wardle. Attitudes were measured using a questionnaire adapted from the Pan-EU Survey on Consumer Attitudes to Physical Activity, Body-weight and Health. Food, alcohol consumption and exercise were measured using a 7-day reported dietary/exercise diary. Nutrient intake data were determined using dietary analysis. Weight, height and waist circumference were measured and body mass index (BMI) calculated. When starting college, student home economics teachers have broadly similar anthropometric, dietary and lifestyle characteristics to those of their contemporaries. Mean BMI was identical [24.4 kg/m2 (SD 4.3)] to that reported in the North/South Ireland Food Consumption Survey (NSIFCS) for those aged 18,35 years, although energy intakes were significantly higher in the cohort of student teachers (P = 0.000). Thirty-eight per cent were overweight or obese vs. 33.6% in the NSIFCS. Only 17% (n = 6) of students achieved an intake of 300 µg/day of folate as recommended by the Food Safety Authority of Ireland and only one the recommended intake of non-starch polysaccharides (18 g/day). One in three students in this study smoke (16 of 48) and alcohol consumption was high. Only one student was very active. Students scored a mean of 55% (SD 8%) on the knowledge test, with similar scores attained for specific aspects of nutritional knowledge (i.e. food groups, constituents of foods, current dietary advice, nutrients, lifestyle practices). However, knowledge of nutrition definitions was weaker with a mean score of 31% (SD 8.6%). Students had a positive attitude towards food choice, the link between food and health and control over their own diet. Similar attitudes towards exercise, smoking and alcohol consumption were displayed despite students perceiving themselves as not having a balanced diet, having insufficient exercise and having regretted something done as a result of consuming alcohol. They appear to display optimistic bias in relation to health risks. These findings provide baseline data for the longitudinal study and indicate that those choosing to pursue a career as a home economics teacher in Ireland have similar nutritional and lifestyle characteristics to those of their contemporaries. [source]


    Hair biology: an update

    INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2002
    B. A. Bernard
    Synopsis In the past few years, the hair follicle has started revealing its beauty and mysteries. The existence of a growth and regeneration cycle, together with a unique tissue organization and complex regulatory network, make it a true paradigm of tissue homeostasis and dermal,epithelial crosstalk. In this brief review, I will describe some of the most recent results obtained in this very active research field of hair biology, underlining the diversity of the molecular signals that control hair growth and pigmentation. Résumé Au cours des dernières années, le follicule pileux a commencéà révéler sa beauté et ses mystères. L'existence d'un cycle de croissance et de régénération, d'une organization tissulaire unique et d'un circuit complexe de régulation désigne le follicule pileux comme un paradigme d'homéostasie tissulaire et d'interactions dermo,épithéliales. Dans cette courte revue, je décris quelques uns des résultats récemment obtenus dans ce domaine de recherche très actif, en soulignant l'extrême diversité des signaux moléculaires qui contrôlent la croissance du cheveu et sa pigmentation. [source]


    Development of a Supported Ionic Liquid Phase (SILP) Catalyst for Slurry-Phase Friedel,Crafts Alkylations of Cumene

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009
    J. Joni
    Abstract A supported ionic liquid phase (SILP) catalyst material has been developed based on a silica support coated with an acidic chloroaluminate ionic liquid. Compared to the results in a liquid-liquid biphasic reaction these materials showed in the isopropylation of cumene a clearly different selectivity which was found to be related to a reduction of the ionic liquid's acidity by the untreated silica support. By pretreating the support with a defined amount of ionic liquid for neutralization and removal of surface hydroxy groups, a well defined, very active and also very selective SILP catalyst for slurry phase Friedel,Crafts alkylation was obtained. [source]


    Rhodium Complexed C2 -PAMAM Dendrimers Supported on Large Pore Davisil Silica as Catalysts for the Hydroformylation of Olefins

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2005

    Abstract Polyamidoamine (PAMAM) dendrimers up to the third generation were grown for the first time on the surface of a large-pore (18,nm) Davisil silica support. The supported dendrimers of generations 0, 1, 2 and 3 were phosphinomethylated and complexed with rhodium. All the generations were found to be very active for the hydroformylation of olefins. The hydroformylation of 1-octene was accomplished with a turnover frequency of 1700,h,1 at 70,°C. The G(1) material was found to be the most active when the different generations were compared at 50% conversion at 70,°C [source]


    Deproteinized cancellous bovine bone (Bio-Oss®) as bone substitute for sinus floor elevation

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 3 2003
    A retrospective, histomorphometrical study of five cases
    Abstract Objectives: To study in detail the performance of deproteinized cancellous bovine bone (DPBB, Bio-Osso®) granules as a bone substitute, a histomorphometric was performed on five patients treated with DPBB for reconstruction of the severely atrophic maxilla. Material and Methods: DPBB was used as mixture with autogenous bone particles, in concentrations that increased from 20% to 100% DPBB, with the time of healing increasing accordingly from 5 to 8 months. A total of 20 vertical biopsies was taken at the time of fixture installation and used for histomorphometry as undecalcified Goldner stained sections. Results: The results show that in all cases, the DPBB granules had been interconnected by bridges of vital newly formed bone. The volume of bone in the grafted area correlated inversely with the concentration of DPBB grafted, and varied between 37% and 23%. However, the total volume of mineralized material (bone plus DPI3B granules) remained within the same range in all five patients (between 53% and 59%). The high values for osteoid and resorption surface, and the presence of tartrate-resistant acid phosphatase-positive multinucleated osteoclasts in resorption lacunae, indicated that bone remodeling was very active in all grafts. Osteoclasts were also observed in shallow resorption pits on DPBB surfaces. The percentage DPBB surface in contact with bone remained stable at about 35% and could not be related to the proportion of DPBB grafted. Conclusion: Although the number of patients examined was limited, the data suggest that deproteinized cancellous bovine bone, preferably combined with autogenous bone particles, is a suitable material for sinus floor elevation in the severely atrophic human maxilla. Zusammenfassung Ent-Proteinisierter spöngiöser boviner Knochen (Bio-Oss) als Knochenersatz zur Sinusboden-Elevation. Eine retrospektive histomorphometrische Studie an 5 Fällen. Ziele:Um das Verhalten Ent-Proteinisierten spöngiösen bovinen Knochengranulats (DPBB, Bio,Oss) als Knochenersatzmaterial detailliert zu studieren, wurde an 5 Patienten, die mit DPBB zur Rekonstruktion der stark atrophischen Maxilla behandelt wurden, eine histomorphometrische Studie durchgeführt. Material und Methoden:DPBB wurde als Mischung mit autogenen Knochenpartikeln in einer Konzentration von 20 , 100% DPBB verwendet. Die Heilungsdauer wurde entsprechend von 5 auf 8 Monate erhöht. Zum Zeitpunkt der Implantatsetzung wurden insgesamt 20 vertikale Biopsien entnommen und für die Histomorphometrie als nicht-entkalkte, Goldner-gefärbte Schnitte verwendet. Ergebnisse: Die Ergebnisse zeigten in allen Fällen, dass die DPBB-Granula über Brücken von vitalem neu gebildetem Knochen miteinander verbunden waren. Das Volumen des Knochens in dem transplantiertem Gebiet korrelierte umgekehrt mit der Konzentration der transpantierten DPBB und variierte zwischen 37% und 23%. Jedoch lag das Gesamtvolumen des mineralisierten Materials (Knochen+DPBB-Granula)bei allen 5 Patienten im selben Bereich (zwischen 53% und 59%). Die hohen Werte für Ostoid und Resorptionsflächen sowie die Anwesenheit von TRAP-positiven multinukleären Osteoklasten in Resorptionslakunen, zeigte, dass das Knochenremodelling in allen Transplantaten sehr aktiv war. Auch in flachen Resorpionsgrübchen auf der DPBB-Oberfläche wurden Osteoklasten beobachtet. Der Prozentsatz der DPBB-Oberfläche welche im Knochenkontakt war blieb mit etwa 35% stabil und korrelierte nicht mit dem Anteil des transplantierten DPBBs. Schlussfolgerung:Obwohl die untersuchte Patientenzahl sehr gering ist, lassen die Daten vermuten, dass Ent-Proteinisierter spöngiöser boviner Knochen, vorzugsweise mit autogenen Knochenpartikeln kombiniert, ein geeignetes Material für die Sinusboden-Elevation bei stark atrophischer Maxilla ist. Résumé Os bovin spongieux déprotéiné comme substitut osseux dans l'épaississement sinusal. Une étude histomorphométrique rétrospective de cinq cas Le but de cette étude a été d'analyser en détail les performances de l'os bovin spongieux déprotéiné (DPBB, Bio-Oss®) en granules comme substitut osseux par une analyse histomorphométrique effectuée chez cinq patients traités pour une reconstruction au niveau d'un maxillaire sévèrement atrophié. DPBB a été utilisé en mélange avec des particules osseuses autogènes en concentrations augmentaient de 20 à 100% de DPBB, avec un temps de guérison augmentant paralèllement de cinq à huit mois. Vingt biopsies verticales ont ainsi été prélevées au moment du placement des implants et utilisées pour l'histomorphométrie sur coupes colorées Goldner non-décalcifiées. Les résultats ont indiqué que dans tous les cas les granules DPBB ont été interconnectées par des bridges d'os néoformé vivant. Le volume d'os dans l'aire greffée était en corrélation inverse avec les concentrations de DPBB greffées et variait entre 37 et 23 %. Cependant le volume total de matériel minéralisé (os+granules DPBB) restait dans les mêmes moyennes chez les cinq patients (entre 53 et 59 %). Les valeurs importantes pour la surface de résorption et ostéides, et la présence d'ostéoclastes multinucléaires positifs au TRAP dans les lacunes de résorption indiquaient que le remodelage osseux était très actif dans tous les greffons. Les ostéoclastes étaient également observés dans des petites crevasses de résorption étroites sur les surfaces DPBB. Le pourcentage DPBB en contact avec l'os demeurait stable à environ 35% et ne pouvait pas être mis en relation avec la proportion de DPBB greffé. Bien que le nombre de patients examinés aie été très limité, les données suggèrent que l'os bovin spongieux déprotéiné de préférence en combinaison avec des particules d'os autogène est un bon matériel pour l'épaississement du plancher sinusal en présence de maxillaire humain sévèrement atrophié. [source]


    The distribution and diversity of amphibian fauna of Lake Nabugabo and surrounding areas

    AFRICAN JOURNAL OF ECOLOGY, Issue 2004
    M. Behangana
    Abstract Six major vegetation types surrounding Lake Nabugabo were sampled for amphibians. These types were: shoreline zone (habitat type code A) representing vegetation on the shoreline about 2 m from the shoreline; Miscanthidium violaceum (B); Eragrostis-Loudetia (C); swamp forest (D); Cyperus papyrus (E); and medium altitude evergreen forest (F). A total of 168 days were spent in the field with a total of 288 1 h counts. Forty-eight counts were carried out in each vegetation type. Sampling was carried out between 17.00 and 24.00 h to coincide with the time amphibians are very active. Twenty-four species were recorded during the study period. These account for about 27.9% of total number of amphibian species recorded in Uganda. Four families were identified, which included: Ranidae (12 spp.), Hyperolidae (8 spp.), Bufonidae (3 spp.) and Pipidae (1 sp.). There was substantial variation in observed species composition among vegetation types. The most species rich habitat was the Eragrostis-Loudetia vegetation zone (17 spp.), followed by the swamp forest zone (14 spp.), then the M. violeceum swamp (11 spp.) and the shoreline (10 spp.). The most species poor sites were C. papyrus swamp (6 spp.) followed by the medium altitude forest (7 spp.). In terms of species abundance, the swamp forest and the M. violecium zones were the most important amphibian habitats for the common species while the Eragrostis-Laudetia zone stood out as the most important for the rare species. From the data collected, it can be deduced that the three most important habitats for the conservation of amphibian fauna in the study area are the Eragrostis-Laudetia, M. violeceum and the swamp forest zones. [source]


    Classic and soma-restricted proteolipids are targeted to different subcellular compartments in oligodendrocytes

    JOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2001
    Ernesto R. Bongarzone
    Abstract The myelin proteolipid (PLP) gene is very active in oligodendrocytes (OLs) and generates at least four proteins: the classic PLP and DM20 proteolipids, which are associated with compact myelin and the srPLP and srDM20, which are associated with the cell soma. These proteins are extremely hydrophobic and appear to follow the biosynthetic route used by secretory proteins. In this study, we have analyzed the subcellular distribution of the newly described sr-proteolipids and compared it to that of the classic proteolipids. Immunocytochemical analysis indicates that the sr-proteolipids and classic proteolipids are found in association with the endoplasmic reticulum (ER) and Golgi apparatus of mature OLs in vitro. Whereas the classic proteolipids become associated with the myelin-like sheets elaborated by OLs, the sr-proteolipids are not targeted to the myelin leaflets. The sr-proteolipids were associated with endosomes and with recycling vesicles as determined by double immunocytochemistry with markers such as syntaxin 6 and clathrin. In vivo, immunohistochemical analysis showed a distribution of the sr-proteolipids that was similar to that obtained in vitro, with a total absence of incorporation of sr-proteolipids into compact myelin. This differential subcellular localization is further evidence for a biological role for these products of the PLP/DM20 gene, which is different from that of the classic proteolipids. J. Neurosci. Res. 65:477,484, 2001. © 2001 Wiley-Liss, Inc. [source]


    Pathogenesis of Potato Gangrene Caused by Phoma exigua var. foveata: II.

    JOURNAL OF PHYTOPATHOLOGY, Issue 7 2004
    Activities of some Hydrolases, Dehydrogenases
    Abstract The location of enzyme activity in gangrene-diseased tubers was determined using the nitrocellulose blotting method. The activity of aminopeptidase and esterase was located in tissues adjacent to dry rot caused by Phoma exigua var. foveata and in other apparently healthy tissues. The activity of glucuronidase, succinic and glucose-6-phosphate dehydrogenases (G-6-PDH), however, was confined to tissues adjacent to the rotted tissue. The pathogen produces very active , - and , -glycosidases, so their highest activity occurred in rotten tissue that was filled with fungal mycelium. Results suggest that all these enzymes are involved in alteration of cell metabolism and the destruction of diseased tuber tissue. [source]


    A new tetradentate ligand for atom transfer radical polymerization

    JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 14 2004
    Shijie Ding
    Abstract The properties of a ligand, including molecular structure and substituents, strongly affect the catalyst activity and control of the polymerization in atom transfer radical polymerization (ATRP). A new tetradentate ligand, N,N,-bis(pyridin-2-ylmethyl-3-hexoxo-3-oxopropyl)ethane-1,2-diamine (BPED) was synthesized and examined as the ligand of copper halide for ATRP of styrene (St), methyl acrylate (MA), and methyl methacrylate (MMA), and compared with other analogous linear tetrdendate ligands. The BPED ligand was found to significantly promote the activation reaction: the CuBr/BPED complex reacted with the initiators so fast that a large amount of Cu(II)Br2/BPED was produced and thus the polymerizations were slow for all the monomers. The reaction of CuCl/BPED with the initiator was also fast, but by reducing the catalyst concentration or adding CuCl2, the activation reaction could be slowed to establish the equilibrium of ATRP for a well-controlled living polymerization of MA. CuCl/BPED was found very active for the polymerization of MA. For example, 10 mol% of the catalyst relatively to the initiator was sufficient to mediate a living polymerization of MA. The CuCl/BPED, however, could not catalyze a living polymerization of MMA because the resulting CuCl2/BPED could not deactivate the growing radicals. The effects of the ligand structures on the catalysis of ATRP are also discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3553,3562, 2004 [source]


    Physical Activity Pattern of Prepubescent Filipino School Children During School Days

    JOURNAL OF SCHOOL HEALTH, Issue 7 2009
    Consuelo B. Gonzalez-Suarez MD
    ABSTRACT Background:, Little is known about pre-pubescent Filipino children's involvement in moderate-to-vigorous physical activity (MVPA). There are international guidelines regarding required levels of MVPA for healthy children. Methods:, This study describes participation of 11- to 12-year-olds in randomly selected public and private schools in San Juan, Metromanila, in MVPA and sports during a school day. The Filipino-modified Physical Activity Questionnaire for Older Children (F_PAQ_C) was administered in English and Filipino. Additional data was collected on sex, age, type of school, and amount of time spent using television and computers. Children's self-assessment of physical activities (1 question in the F_PAQ_C) was correlated with their cumulative F_PAQ_C score. Results:, Three hundred eighty subjects (167 boys, 213 girls) participated. Participation in MVPA varied between sex and age groups, from 56.1% to 65.0%. Fewer than 10% of participants were very active. The children were more active during physical education classes than at recess or lunch, after class, or in the evening. Walking for exercise, jumping, jogging and running, free play, and dance were most common. Boys, younger children, and private school students most commonly engaged in MVPA. Self-assessed physical activity had modest correlation (r2= 0.21) with cumulative F_PAQ_C score, after adjusting for sex, age, and school type. Conclusion:, Most children were not physically active during the school day, except in physical education classes. To reduce the gap between recommended and current activity levels, more opportunities should be provided for preteen Filipino children to engage in MVPA during and after school. [source]


    In vitro anti-biofilm activity of Boswellia spp. oleogum resin essential oils

    LETTERS IN APPLIED MICROBIOLOGY, Issue 5 2008
    D. Schillaci
    Abstract Aims:, To evaluate the anti-biofilm activity of the commercially available essential oils from two Boswellia species. Methods and Results:, The susceptibility of staphylococcal and Candida albicans biofilms was determined by methyltiazotetrazolium (MTT) staining. At concentrations ranging from 217·3 ,g ml,1 (25% v/v) to 6·8 ,g ml,1 (0·75% v/v), the essential oil of Boswellia papyrifera showed considerable activity against both Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213 biofilms. The anti-microbial efficacy of this oil against S. epidermidis RP62A biofilms was also tested using live/dead staining in combination with fluorescence microscopy, and we observed that the essential oil of B. papyrifera showed an evident anti-biofilm effect and a prevention of adhesion at sub-MIC concentrations. Boswellia rivae essential oil was very active against preformed C. albicans ATCC 10231 biofilms and inhibited the formation of C. albicans biofilms at a sub-MIC concentration. Conclusions:, Essential oils of Boswellia spp. could effectively inhibit the growth of biofilms of medical relevance. Significance and Impact of the Study:,Boswellia spp. essential oils represent an interesting source of anti-microbial agents in the development of new strategies to prevent and treat biofilms. [source]


    Parkinson's disease: 10 years of progress, 1997,2007,,

    MOVEMENT DISORDERS, Issue S1 2010
    Stanley Fahn MD
    Abstract Many people with Parkinson's disease (PD) and their family members ask their physicians "What is happening in research on Parkinson's disease? Is there anything new?" As the initial speaker at the symposium organized by the Parkinson's Disease Foundation in celebration of its 50th anniversary, I sought to address these questions, focusing on research published between the years 1997 and 2007. I cataloged the advances I considered most important in the field, recognizing my viewpoint is a subjective one and most likely differs from similar listings that others would put together. Space limitation allows me to discuss only a tiny fraction of the remarkable new findings that have been discovered during this 10-year span. Nevertheless, I expect the readers of this summation of advances in the field to be as impressed as I am on the wealth, breadth, and excitement stirring in the field of PD research. Included in this overview are highlights in both laboratory science and clinical science of PD research. In the former category are advances in knowledge on the genetics of PD; potential etiologic and pathogenic causes, especially the better understanding of endogenous factors within dopaminergic neurons; pathologic changes including deposition of alpha-synuclein aggregates; and the consequences of altered alpha-synuclein on the degradation of proteins by both the ubiquitin-proteasomal pathway and the lysosome. Clinical science has also been very active and impressively productive with important clinical advances. In this category are new information on the epidemiology of PD, including awareness of additional factors (besides smoking) that might slow the onset and worsening of PD, such as caffeine and urate; neuroimaging with positron emission tomography and single photon emission tomography; keener awareness of nonmotor features of PD and their impact on quality of life for the persons with PD and their family; recognition of behavioral complications of medications utilized to treat PD, such as impulse control problems; appreciation of the natural history of PD with the increasing impairments as the disease relentlessly worsens over time; the many controlled clinical trials attempting to slow the progression of the disease and to provide new symptomatic therapies; and surgical approaches to alleviate symptoms and progression, including cellular and gene therapy as well as deep brain stimulation. © 2010 Movement Disorder Society [source]


    The performance of QoS-aware IP multicast routing protocols,

    NETWORKS: AN INTERNATIONAL JOURNAL, Issue 2 2003
    Chih-Jen Tseng
    Abstract Research in the area of QoS-aware dynamic multicast routing protocols has been very active in recent years. Protocols based on dynamic Steiner tree strategies, such as YAM and QoSMIC, have been consistently shown to outperform those based on shortest path heuristics, such as PIM and DVMRP. However, these protocols all suffer from the problem of poor scalability for one or more of the following reasons: high control overhead, insufficient robustness with the adoption of a centralized group manager, and excessively long join latency. In addition, these protocols perform well only when group members are either densely populated or sparsely populated, but, unfortunately, not both. In this paper, we propose a protocol, named DSDMR, which can adapt its strategy based on sensed group member densities. Underlying DSDMR is an adaptive two-direction join mechanism that tries to find good attaching points for new group members either from the source or from the new joining member depending on member densities. We evaluate our scheme using extensive simulations and found that DSDMR can build multicast trees with costs close to the best greedy strategy, very low control overhead, and very short join latency across a wide member density spectrum. Furthermore, its success ratio is only slightly lower than is the best greedy strategy in finding feasible routes subject to both bandwidth and end-to-end delay constraints. © 2003 Wiley Periodicals, Inc. [source]


    (615) Combined Use of Cervical Spinal Cord Stimulator (SCS) and Occipital Nerve Stimulator (ONS)

    PAIN MEDICINE, Issue 2 2000
    Article first published online: 25 DEC 200
    Author: Y. Eugene Mironer, Carolinas Center for Advanced Management of Pain A 51-year-old female patient was referred to the clinic in March 1997 with severe cervicalgia and right shoulder girdle pain. She rated her pain at 9/10 on a Visual Analog Scale (VAS). MRI showed multilevel severe spondylosis with significant neural foraminal stenosis at 3 levels. Multiple modalities of treatment (physiotherapy, epidural steroid injections, cervical plexus blocks) and a variety of medications (opioids, NSAIDs, anticonvulsants, antidepressants, etc.) failed to provide any improvement. The patient twice consulted neurosurgeons but was considered a poor surgical candidate. Finally, in July 1997, after a successful trial, a cervical SCS was implanted with the tip of the lead at level C2, achieving excellent coverage of the pain area. For the next 18 months the patient continued to do well, having minimal neck and shoulder discomfort and using only occasional oral analgesics. However, by January 1999, she developed intractable right-sided occipital neuralgia. Occipital nerve blocks were providing extremely short-term relief and the intake of different analgesics, including opioids, started to increase. In March 1999, after successful trial, an ONS was implanted. Unfortunately, it migrated shortly after implantation and had to be revised and re-anchored. After this procedure all headaches were completely controlled without medications. The patient continues to be very active, uses both stimulators daily, does not take any analgesics and rates her pain at 0/10 to 1/10 on VAS. [source]


    Carbon nanotube-supported bimetallic palladium,gold electrocatalysts for electro-oxidation of formic acid

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2010
    Cheng-Han Chen
    Abstract It is known that palladium-based catalysts are initially very active in direct formic acid oxidation but they suffer from fast deactivation caused by a strongly adsorbed CO intermediate. Reactivation of the catalysts involving application of anodic potential may cause palladium dissolution. The aim of the present study is to increase the stability and performance of palladium-based catalysts in direct formic acid fuel cells (DFAFCs). Preparation and characterization of palladium/multiwalled carbon nanotubes (Pd/MWCNTs) and towards formic acid oxidation via different treatments are described. The catalysts were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and cyclic voltammetry (CV). It was shown that the Pd and Pd,Au MWCNTs supported catalysts after reduction in H2,Ar at 200,°C (R200 treatment) were highly active in formic acid electro-oxidation, whereas the catalysts after heating in argon at 250,°C (C250 treatment) were inactive. The catalysts after hydrogen treatment have smaller metal particles and better contact with MWCNTs support. CV, simulating reactivation of the catalysts, showed that the Pd catalyst suffers from severe Pd dissolution, whereas for the Pd,Au selective leaching of Pd is considerably slower. [source]


    Antibacterial activity of medicinal plant extracts against periodontopathic bacteria

    PHYTOTHERAPY RESEARCH, Issue 6 2003
    L. Iauk
    Abstract This study was performed to evaluate the antibacterial activity of Althaea of,cinalis L. roots, Arnica montana L. ,owers, Calendula of,cinalis L. ,owers, Hamamelis virginiana L. leaves, Illicium verum Hook. fruits and Melissa of,cinalis L. leaves, against anaerobic and facultative aerobic periodontal bacteria: Porphyromonas gingivalis, Prevotella spp., Fusobacterium nucleatum, Capnocytophaga gingivalis, Veilonella parvula, Eikenella corrodens, Peptostreptococcus micros and Actinomyces odontolyticus. The methanol extracts of H. virginiana and A. montana and, to a lesser extent, A. of,cinalis were shown to possess an inhibiting activity (MIC , 2048 mg/L) against many of the species tested. In comparison, M. of,cinalis and C. of,cinalis extracts had a lower inhibiting activity (MIC , 2048 mg/L) against all the tested species with the exception of Prevotella sp. Illicium verum methanol extract was not very active though it had a particular good activity against E. corrodens. The results suggest the use of the alcohol extracts of H. virginiana, A. montana and A. of,cinalis for topical medications in periodontal prophylactics. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Catalytic behavior of wool,Rh complex in asymmetric hydrogenation of 2-methyl furan,

    POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3-5 2003
    Man He
    Abstract A Wool,Rh complex was prepared by the reaction of wool with RhCl3·3H2O in ethanol solution, and was found to be useful as a chiral catalyst for the asymmetric hydrogenation of 2-methyl furan to (S)-(+)-2-methyl tetrahydrofuran at 28,°C and under atmospheric hydrogen pressure. When an appropriate Rh content in the Wool,Rh complex was selected, the yield and optical yield amounted to 53.7 and 76.9%, respectively, and the Wool,Rh complex catalyst could be reused several times without any noticeable loss in its optical catalytic activity. Wool is a very cheap natural biopolymer ligand, and Wool,Rh complex is very easy to prepare, and it is a very active, enantioselective and stable chiral catalyst for asymmetric hydrogenation of 2-methyl furan. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Light and Electron Microscopic Study of the Thyroid Gland of the Camel (Camelus dromedarius)

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2000
    E. M. Abdel-Magied
    The thyroid gland of sexually immature dromedary camels was studied using both light and electron microscopy. The thyroid gland contained follicles of different sizes in both summer and winter. However, most of the follicles were large in summer and small in winter. The large follicles were lined by very low cuboidal or semi-squamous follicular cells whereas the small ones were lined by high cuboidal or low columnar follicular cells. Electron microscopy showed that the very low cuboidal follicular cells were poor in organelles and were considered hypoactive. High cuboidal follicular cells on the other hand, were rich in organelles that included mitochondria, cisternae of rough endoplasmic reticulum, secretory vesicles, colloid droplets, heterosomes and autophagic vacuoles; they were considered to be very active. The possible role played by these organelles in synthesis of thyroglobulin and liberation of tri- and tetraiodothyronine is discussed. A few degenerate follicular cells were infrequently encountered in the camel thyroid. Parafollicular (C) cells were not seen in this study either with light or electron microscopy. [source]


    Charity and self-help: Migrants' social networks and health care in the homeland (Respond to this article at http://www.therai.org.uk/at/debate)

    ANTHROPOLOGY TODAY, Issue 4 2010
    Abdoulaye Kane
    This article examines the delivery of healthcare by Haalpulaar immigrants' village association in France to their rural villages in Senegal. In the context of the neo-liberal reforms in Senegal, the Haalpulaar immigrants have been very active in funding community project in the health sector for their communities of origin left to fend for themselves by the State. Haalpulaar migrants associations like TAD (Thilogne Association Developpement) and Fuuta Santé are improving access to healthcare in the Senegal River valley through the remittances of biomedicine, medical equipment as well as the organization of annual health caravans with the participation of French health professionals and local partners. [source]


    Amino-acid hydroselenites: synthesis and cytotoxicity,

    APPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2002
    E. Lukevics
    Abstract Amino acids, di- and tri-peptides readily react with selenic acid (H2SeO3, formed during solution of selenium(IV) oxide in water) to give the corresponding ammonium hydroselenites. Most selenites synthesized are very active (0.4,11,µg,ml,1) against mouse hepatoma MG-22A and readily increase NO concentration in the cultural medium on the HT-1080 line (up to TG100,=,1500%). The amino-acid hydroselenites studied influenced the cell phenotype. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Ir A.H. de Voogt: life and career of a radio pioneer

    ASTRONOMISCHE NACHRICHTEN, Issue 5 2007
    R.G. Strom
    Abstract There are probably few radio astronomers who would be able to recall A.H. de Voogt, which is unfortunate, but at the same time unsurprising: for he published no original astronomical research, never carried out pioneering observations, nor is his name linked to either theoretical or instrumental breakthroughs. Yet he was described by the man who first observed the 21 cm hydrogen line from the Netherlands as a radio astronomy pioneer, at the very birth of the Dutch effort. He was, moreover, a trail blazer at the cutting edge of radio, not once but twice in his career. Without him it is unlikely that the 21 cm line would have been observed in the Netherlands in 1951, and arguably the H I mapping of the Milky Way under Jan Oort's leadership would have taken place much later, if at all. Radio astronomy observing itself might well have been compromised by interference had it not been for De Voogt's foresight. Anthonet Hugo de Voogt (1892,1969) built, while still a teenager, one of the very first amateur radio stations (call letters VO: · · · ,/, , ,) in Holland, earned the radio-telegrapher's diploma during his student days, and was intimately involved in the foundation of the Dutch Society for Radio-Telegraphy in 1916. Until the 1920s, he was very active in amateur radio and astronomy circles. Trained in electrical engineering at Delft, he joined the PTT (Post Office) as a telegraph engineer in 1919, worked his way through the ranks to become head of the telephone district of Breda in 1939, and was promoted to head the PTT Radio Service just days after the end of the war. As his department was responsible for overseas radio communication, he initiated a research effort to study radio propagation in the ionosphere and the effects of solar activity. To this end, he rescued a number of Würzburg-Riese 7.5-m radar antennas abandoned at the end of the war, made one available for Jan Oort's H I work, and launched a series of radio astronomical initiatives. His group also built a number of antennas, monitored solar emission, and participated in the International Geophysical Year (1957,1958). (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Modulation of aggressive behaviour by fighting experience: mechanisms and contest outcomes

    BIOLOGICAL REVIEWS, Issue 1 2006
    Yuying Hsu
    ABSTRACT Experience in aggressive contests often affects behaviour during, and the outcome of, later contests. This review discusses evidence for, variations in, and consequences of such effects. Generally, prior winning experiences increase, and prior losing experiences decrease, the probability of winning in later contests, reflecting modifications of expected fighting ability. We examine differences in the methodologies used to study experience effects, and the relative importance and persistence of winning and losing experiences within and across taxa. We review the voluminous, but somewhat disconnected, literature on the neuroendocrine mechanisms that mediate experience effects. Most studies focus on only one of a number of possible mechanisms without providing a comprehensive view of how these mechanisms are integrated into overt behaviour. More carefully controlled work on the mechanisms underlying experience effects is needed before firm conclusions can be drawn. Behavioural changes during contests that relate to prior experience fall into two general categories. Losing experiences decrease willingness to engage in a contest while winning experiences increase willingness to escalate a contest. As expected from the sequential assessment model of contest behaviour, experiences become less important to outcomes of contests that escalate to physical fighting. A limited number of studies indicate that integration of multiple experiences can influence current contest behaviour. Details of multiple experience integration for any species are virtually unknown. We propose a simple additive model for this integration of multiple experiences into an individual's expected fighting ability. The model accounts for different magnitudes of experience effects and the possible decline in experience effects over time. Predicting contest outcomes based on prior experiences requires an algorithm that translates experience differences into contest outcomes. We propose two general types of model, one based solely on individual differences in integrated multiple experiences and the other based on the probability contests reach the escalated phase. The difference models include four algorithms reflecting possible decision rules that convert the perceived fighting abilities of two rivals into their probabilities of winning. The second type of algorithm focuses on how experience influences the probability that a subsequent contest will escalate and the fact that escalated contests may not be influenced by prior experience. Neither type of algorithm has been systematically investigated. Finally, we review models for the formation of dominance hierarchies that assume that prior experience influences contest outcome. Numerous models have reached varied conclusions depending on which factors examined in this review are included. We know relatively little about the importance of and variation in experience effects in nature and how they influence the dynamics of aggressive interactions in social groups and random assemblages of individuals. Researchers should be very active in this area in the next decade. The role of experience must be integrated with other influences on contest outcome, such as prior residency, to arrive at a more complete picture of variations in contest outcomes. We expect that this integrated view will be important in understanding other types of interactions between individuals, such as mating and predator-prey interactions, that also are affected significantly by prior experiences. [source]


    Synthesis, Cruzain Docking, and in,vitro Studies of Aryl-4-Oxothiazolylhydrazones Against Trypanosoma cruzi

    CHEMMEDCHEM, Issue 9 2007
    Cristina, Lima Leite Prof.
    Abstract Research in recent years has demonstrated that the Trypanosoma cruzi cysteine protease cruzain (TCC) is a valid chemotherapeutic target. Herein we describe a small library of aryl-4-oxothiazolylhydrazones that have been tested in assays against T.,cruzi cell cultures. The docking studies carried out suggest that these compounds are potential ligands for the TCC enzyme. The most promising compound of this series, N -(4-oxo-5-ethyl-2,-thiazolin-2-yl)- N,-phenylthio-(Z)-ethylidenehydrazone (6,f), was shown to be very active at non-cytotoxic concentrations in in,vitro assays with mammalian cells and has a potency comparable with reference drugs such as nifurtimox (Nfx) and benznidazole (Bdz). [source]


    Dynamics of gonococcal type IV pili during infection

    CHEMPHYSCHEM, Issue 9-10 2009
    Dirk Opitz
    Abstract Keep that motor running: Type IV pili are among the strongest molecular motors characterized to date. Herein it is reported that pilus motors of the human pathogen Neisseria gonorrhoeae are very active for at least one day post-infection of epithelial cells. They generate force in the range on 70 pN and retract at a higher velocity as compared to abiotic environments (see picture). Type IV pili are important bacterial virulence factors that mediate attachment to mammalian host cells and elicit downstream signals. When adhered to abiotic surfaces, the human pathogen Neisseria gonorrhoeae generates force by retracting these polymeric cell appendages. We recently found that single pili generate stalling forces that exceed 100 pN, but it is unclear whether bacteria generate force once they adhere to their human host cells. Here, we report that pili retract very actively during infection of human epithelial cells. The retraction velocity is bimodal and the high velocity mode persisted at higher forces in contrast to an abiotic environment. Bacteria generate considerable force during infection, but the maximum force is reduced from 120±40 pN on abiotic surfaces to 70±20 pN on epithelial cells, most likely due to elastic effects. Velocity and maximum force of pilus retraction are largely independent of the infection period within 1 h and 24 h post-infection. Thus, the force generated by type IV pili during infection is high enough to induce cytoskeletal rearrangements in the host cell. [source]


    New Generation of Gold Catalysts: Nanoporous Foams and Tubes,Is Unsupported Gold Catalytically Active?

    CHEMPHYSCHEM, Issue 13 2007
    Masatake Haruta Prof. Dr.
    Gold fever: Gold turns out to be catalytically very active, provided that either one or two of the three conditions shown in the graphic are fulfilled. In CO oxidation at room temperature even unsupported gold is active in the presence of alkaline water. The active states of gold in the gold catalysts reported so far can be classified into four groups: bulk gold, nanoparticles, clusters or thin layers with specific sizes, and cations. [source]